7291

TWIST1

twist family bHLH transcription factor 1;TWIST1;twist family bHLH transcription factor 1

B-HLH DNA binding protein|H-twist|TWIST homolog of drosophila|class A basic helix-loop-helix protein 38|twist basic helix-loop-helix transcription factor 1|twist homolog 1|twist-related protein 1

7p21.2

protein-coding

Endothelin receptor B (ET(B)R) is a G-protein-coupled receptor overexpressed in melanoma, blood, and lymphatic endothelial cells. Given that aberrant signal transduction can be mediated through cross talk between receptors, here, we explore the functional relationship between ET(B)R and the vascular endothelial growth factor receptor (VEGFR)-3 system and how this cross talk might influence the aggressive behavior of melanoma cells. The expression of VEGFR-3 and its ligands, VEGF-C and VEGF-D, significantly increased after activating ET(B)R by ET-1 in primary and metastatic melanoma cell lines. These effects, similarly to those induced by hypoxia, were mediated by hypoxia-inducible factor (HIF)-1alpha and HIF-2alpha. ET-1 caused the phosphorylation of VEGFR-3, which was accompanied by the activation of the downstream signaling molecules, such as MAPK and AKT. Inhibition of c-Src activity or silencing of the scaffold protein beta-arrestin-1 reduced ET-1-induced VEGFR-3 phosphorylation, demonstrating that, upon ET-1 stimulus, beta-arrestin-1 is involved with c-Src in the ET(B)R-mediated VEGFR-3 transactivation. Moreover, ET-1 in combination with VEGF-C further increased VEGFR-3, MAPK, and AKT phosphorylation and markedly promoted cell migration and vasculogenic mimicry. Dual inhibition of ET(B)R and VEGFR-3 was required for the effective inhibition of these effects, as well as for VEGFR-3 phosphorylation, demonstrating that ET(B)R cross talk with VEGFR-3 enhances cell plasticity and motility. Finally, in melanoma xenografts, ET(B)R antagonist inhibited tumor growth and the activation of the VEGF-C/VEGFR-3 axis, indicating that targeting ET(B)R may improve melanoma treatment acting directly or indirectly by impairing ET(B)R cross talk with VEGFR-3.

The dynamic nature of cancer stem cells that underlie metastasis or their ability to switch between different cellular identities, as in EMT and MET, has profound implications for cancer therapy. The functional relationship between molecules involved in cancer cell stemness and metastasis is not clear. In this regard, our studies on hGBM tissue grade IV specimens showed significant expression of Twist1 and Sox2, known mesenchymal and stemness related markers, respectively, indicating their association with glial tumor genesis and metastasis. The glioma stem cells obtained from CD133+ cells demonstrated increased expression of Twist1 and Sox2 accompanied by significant increase in the mesenchymal markers such as N-cadherin, vimentin and beta-catenin. Our studies on glioma stem cells treatment with human umbilical cord blood derived- mesenchymal stem cells, showed down regulation of Twist1 and Sox2 proteins, apart from other mesenchymal stem cell markers. Based on the in vitro experiments and in vivo intracranial xenograft mouse model studies, we elucidated the potential therapeutic role of hUCBSC in suppressing glioma cancer stemness by the induction of MET.

PURPOSE: Micrometastatic cells detected in the bone marrow have prognostic significance in breast cancer. These cells are heterogeneous and likely do not exhibit uniform biological behavior. To understand the molecular diversity of disseminated cancer cells that reside in bone marrow, we enriched this cell population and did global gene expression profiling in the context of a prospective clinical trial involving women with clinical stage II/III breast cancer undergoing neoadjuvant chemotherapy. EXPERIMENTAL DESIGN: Enrichment of TACSTD1 (EpCAM)-expressing cells from bone marrow of breast cancer patients was achieved using immunomagnetic beads. Gene expression profiles were compared between enriched cell populations and whole bone marrow from 5 normal volunteers and 23 breast cancer patients after neoadjuvant chemotherapy treatment. Enriched cells from bone marrow samples of breast cancer patients before treatment or at 1 year follow-up were also analyzed (total of 87 data sets). The expression of transcripts specifically detected in enriched cell populations from breast cancer patients was correlated with 1-year clinical outcome using quantitative reverse transcription-PCR in an independent cohort of bone marrow samples. RESULTS: Analysis of EpCAM-enriched bone marrow cells revealed specific expression of a subgroup of transcripts, including the metastasis regulator, TWIST1. Most transcripts identified, including TWIST1, were not expressed in enriched populations of bone marrow from normal volunteers, suggesting that this expression profile reflects a signature of breast cancer bone marrow micrometastases that persist after chemotherapy. In an independent set of bone marrow samples obtained before any treatment, TWIST1 expression correlated with early disease relapse. CONCLUSIONS: Disseminated breast cancer cells present in bone marrow after chemotherapy possess unique transcriptional signatures. Genes whose expression is overrepresented in these cell populations, such as TWIST1, may prove to be excellent markers of early distant relapse in breast cancer patients.

OBJECTIVE: To investigate the expression of Twist, E-cadherin and N-cadherin in breast carcinoma tissue and to analyse their effects on the breast carcinoma differentiation, size, infiltration and metastasis of the breast carcinoma. METHODS: The expression of Twist, E-cadherin and N-cadherin in 56 cases of breast invasive ductal carcinoma, 38 cases of invasive lobular carcinoma, 41 cases of carcinoma in situ and 10 cases of normal breast tissue was detected using immunohistochemistry. RESULTS: (1) The expression rate of Twist in three types of breast carcinoma was 46.4% (26/56), 79.0% (30/38) and 26.8% (11/41) respectively, and the expression of Twist in invasive lobular carcinoma was significantly higher than that in invasive ductal carcinoma and carcinoma in situ (P = 0.002, P = 0.000). The expression rate of E-cadherin in three types of breast carcinoma was 78.6% (44/56), 29.0% (11/38) and 80.5% (33/41) respectively, and the expression of E-cadherin in invasive ductal carcinoma and carcinoma in situ was significantly higher than that in invasive lobular carcinoma (P = 0.000, P = 0.000). The expression rate of N-cadherin in three types of breast carcinoma was 53.6% (30/56), 68.4% (26/38) and 31.7% (13/41) respectively, and the expression of N-cadherin in invasive ductal carcinoma and invasive lobular carcinoma was significantly higher than that in carcinoma in situ (P = 0.033, P = 0.001). (2) In all the 135 cases, the expression of Twist was not correlated with that of E-cadherin (P = 0.005, Spearman correlation coefficient = -0.239), however, there was a positive correlation between the expression of Twist and N-cadherin and statistically significant(P = 0.000, Spearman correlation coefficient = 0.319). (3) In the invasive ductal carcinoma, the expression of N-cadherin in poorly-differentiated carcinoma was significantly higher than that of the moderately-or well-differentiated ones (P = 0.004). (4) In the invasive lobular carcinoma, the expression of Twist in cases with lymph node metastasis was significantly higher than that of cases without metastasis (P = 0.037). CONCLUSIONS: Twist, E-cadherin and N-cadherin have different expression patterns in the three kinds of breast carcinoma. The positive expression of Twist was correlated to lymph node metastasis in invasive lobular carcinoma and the positive expression of N-cadherin was correlated to cell the tissue differentiation in invasive ductal carcinoma. Detection of the expression of these biomarkers may provide a valuable reference for the study of breast carcinoma progression, metastasis and for the judgment of the biological behavior of the carcinoma.

Twist1, a basic helix-loop-helix transcription factor, promotes breast tumor cell epithelial-mesenchymal transition (EMT), invasiveness, and metastasis. However, the mechanisms responsible for regulating Twist1 stability are unknown in these cells. We identified the serine 68 (Ser 68) as a major phosphorylation site of Twist1 by mass spectrometry and with specific antibodies. This Ser 68 is phosphorylated by p38, c-Jun N-terminal kinases (JNK), and extracellular signal-regulated kinases1/2 in vitro, and its phosphorylation levels positively correlate with Twist1 protein levels in human embryonic kidney 293 and breast cancer cells. Prevention of Ser 68 phosphorylation by an alanine (A) mutation (Ser 68A) dramatically accelerates Twist1 ubiquitination and degradation. Furthermore, activation of mitogen-activated protein kinases (MAPK) by an active Ras protein or TGF-beta treatment significantly increases Ser 68 phosphorylation and Twist1 protein levels without altering Twist1 mRNA expression, whereas blocking of MAPK activities by either specific inhibitors or dominant negative inhibitory mutants effectively reduces the levels of both induced and uninduced Ser 68 phosphorylation and Twist protein. Accordingly, the mammary epithelial cells expressing Twist1 exhibit much higher degrees of EMT and invasiveness on stimulation with TGF-beta or the active Ras and paclitaxel resistance compared with the same cells expressing the Ser 68A-Twist1 mutant. Importantly, the levels of Ser 68 phosphorylation in the invasive human breast ductal carcinomas positively correlate with the levels of Twist1 protein and JNK activity and are significantly higher in progesterone receptor-negative and HER2-positive breast cancers. These findings suggest that activation of MAPKs by tyrosine kinase receptors and Ras signaling pathways may substantially promote breast tumor cell EMT and metastasis via phoshorylation and stabilization of Twist1.

Breast cancer metastasis is more resistant to chemotherapy and radiotherapy than is cancer of the visceral tissues; therefore, new treatment strategies are urgently needed. Moscatilin, derived from the orchid Dendrobrium loddigesii, has shown anticancer activity. We evaluated the mechanism by which moscatilin suppresses the migration and metastasis of human breast cancer MDA-MB-231 cells in vitro and in vivo. We demonstrated that moscatilin significantly inhibits MDA-MB-231 cell migration by using scratch assays and Boyden chambers. Transcriptional factors inducing epithelial-mesenchymal transition, such as Twist, Snail, and Akt, play important roles in cell migration and cancer metastasis. Moscatilin inhibited the mRNA and protein expression of Twist, but not that of Snail, and subsequently inhibited N-cadherin expression. However, these effects were reversed by constitutively expressing active myristoylated (myr)-Akt and Twist overexpression. Moscatilin also suppressed Akt phosphorylation. However, Akt overexpression reversed the inhibitory effects of moscatilin on phospho-Akt protein expression but not its effects on Twist. The moscatilin-mediated inhibition of cell migration was reversed by Akt and Twist overexpression, demonstrating that moscatilin blocked cell migration by inhibiting Akt and Twist. In an MDA-MB-231 metastatic animal model, moscatilin (100 mg/kg) significantly suppressed breast cancer metastasis to the lungs and reduced the number of metastatic lung nodules and lung weight without causing any toxicity. These results indicated that moscatilin inhibited MDA-MB-231 cell migration via Akt- and Twist-dependent pathways; this finding was consistent with moscatilin's antimetastatic activity in vivo. Therefore, moscatilin may be an effective compound for the prevention of human breast cancer metastasis.

The FERM domain containing protein Kindlin-3 has been recognized as a major regulator of integrin function in hematopoietic cells, but its role in neoplasia is totally unknown. We have examined the relationship between Kindlin-3 and breast cancer in mouse models and human tissues. Human breast tumors showed a approximately 7-fold elevation in Kindlin-3 mRNA compared with nonneoplastic tissue by quantitative polymerase chain reaction. Kindlin-3 overexpression in a breast cancer cell line increased primary tumor growth and lung metastasis by 2.5- and 3-fold, respectively, when implanted into mice compared with cells expressing vector alone. Mechanistically, the Kindlin-3-overexpressing cells displayed a 2.2-fold increase in vascular endothelial growth factor (VEGF) secretion and enhanced beta1 integrin activation. Increased VEGF secretion resulted from enhanced production of Twist, a transcription factor that promotes tumor angiogenesis. Knockdown of Twist diminished VEGF production, and knockdown of beta1 integrins diminished Twist and VEGF production by Kindlin-3-overexpressing cells, while nontargeting small interfering RNA had no effect on expression of these gene products. Thus, Kindlin-3 influences breast cancer progression by influencing the crosstalk between beta1 integrins and Twist to increase VEGF production. This signaling cascade enhances breast cancer cell invasion and tumor angiogenesis and metastasis.

Cervical carcinoma is associated with high propensity for local invasion and lymph node metastasis. However, the molecular alterations that drive progression and metastasis of cervical cancer remain unclear. Cellular senescence has been proposed as the mechanism that protects an organism against cancer progression and metastasis. In addition, Twist, a basic helix-loop-helix transcription factor, has been suggested as an oncogene because it is overexpressed in many types of human cancer. This gene also exhibits a positive function in regulating invasion and metastasis. In this study, Twist was strongly and positively expressed in normal tissue, squamous cell carcinoma (SCC) IA-IIA, and SCC IIB-IIIB (4.3%, 44%, and 88.9%, respectively). The strong positive expressions of the senescence marker CBX3 were 39.1%, 32%, and 15.6%, respectively. The strong positive expressions of Twist in the SCC groups with or without lymph node metastasis were 80.8% and 50%. For CBX3, such expressions were 7.7% and 29.5%, respectively. Results also showed that the expression of Twist was inversely correlated with that of CBX3. Moreover, the knockdown of Twist with target siRNA in SiHa triggered the induction of the chromatin marker of the cellular senescence CBX3 and senescence-associated beta-galactosidase activity. Our results suggested that the expression of Twist increased during the progression and metastasis of cervical cancer. Furthermore, Twist-induced senescence bypass is important in this process.

Deep vein thrombosis associated with advanced cancer is known as Trousseau's syndrome. We hypothesized that thrombin, an activator of protease-activated receptor (PAR)-1 and PAR-4 contributes to tumor metastasis. In this study, we demonstrated that thrombin and the PAR-1 activating peptide (AP) SFLLRN, but not the PAR-4 AP GYPGKF, induced HIF-1alpha activities, protein expression, and cell motility in colorectal cancer cells, and these actions were significantly inhibited by the PAR-1 antagonist SCH79797. Moreover, thrombin-induced HIF-1alpha activity and cell motility were blocked by inhibiting important mediators of signaling transduction, including the ERK, PI3K, and mTOR pathways. These results showed that thrombin induced HIF-1alpha protein expression through PAR-1 and HIF-1alpha translational de novo protein synthesis. Twist can regulate epithelial-mesenchymal transition (EMT) and increase tumor metastasis. However, we observed that thrombin-induced HIF-1alpha increased Twist mRNA and its protein level was mediated by the modulation of PAR-1 activation and the HIF-1alpha translational pathway. In addition, Twist could increase N-cadherin but not E-cadherin to promote tumor metastasis. Overexpression of dominant-negative HIF-1alpha reversed thrombin-mediated Twist and Twist-induced N-cadherin expression. Moreover, siTwist inhibited Twist-induced N-cadherin and Thrombin-induced cell motility. In conclusion, our study showed that thrombin-induced HIF-1alpha upregulated Twist at the transcriptional level to enhance cell motility. These findings show that thrombin upregulates Twist via HIF-1alpha to make tumor cells malignant and also establish a link between the coagulation disorder and cancer metastasis.

Snail and Twist, transcriptional repressors of E-cadherin as well as inducers of epithelial-mesenchymal transition, play pivotal roles in tumor invasion and metastasis. We investigated the expression of Snail, Twist, and E-cadherin by immunohistochemistry in 193 colorectal cancers, including 79 with positive lymph nodes, 36 with tumor deposits, 39 with both, and 39 with no metastases. Snail was expressed to a greater extent in the group with positive lymph nodes (68.4%), whereas Twist was overexpressed in patients with other metastases (75.0%). Ectopic expression of Snail and Twist correlated with reduced membranous expression of E-cadherin. Importantly, Snail overexpression correlated significantly with lymph node metastasis (P < .0001), whereas Twist up-regulation correlated strongly with other metastases (P < .0001). Multivariate logistic regression analysis showed that Snail was an independent predictor of lymph node metastasis (odds ratio, 4.445; 95% confidence interval, 2.250-8.781; P < .0001), whereas Twist displayed predictive value for metastasis formation (odds ratio, 5.606; 95% confidence interval, 2.829-11.111; P < .0001), suggesting that lymph node and other metastases may follow different signaling pathways. In conclusion, ectopic expression of Snail and Twist contributed to lymph node and disseminated metastasis, respectively, by reducing E-cadherin expression, providing a novel role for Snail and Twist in the progression of colorectal cancer.

PURPOSE: Epithelial-mesenchymal transition (EMT) is a key event in cancer metastasis. This study immunohistochemically examined the expression of EMT-related molecules in both primary colorectal cancer and pulmonary metastases, and analyzed the expression pattern. METHODS: Ten patients with colorectal cancer that underwent surgical resections for both the primary tumor and metastatic pulmonary tumors were included. The expression status of EMT-related molecules was examined using immunohistochemical staining. RESULTS: Nine of the 10 cases maintained the expression of both E-cadherin and beta-catenin in the primary site. The expression of E-cadherin and beta-catenin in the pulmonary metastatic site was preserved in 10 and 12 out of 15 metastatic lesions, respectively. The EMT-related transcription factor, Twist, was positively expressed in all 10 cases, Smad interacting protein 1 (Sip1) in 9, Snail in 4 and Slug in 3 of the primary sites. On the other hand, staining for Twist, Sip1 and Snail at the metastatic pulmonary site, was negative in all 10 cases. CONCLUSION: The expression of EMT-related transcription factors in metastatic pulmonary tumors from colorectal cancer decreased in comparison to the primary tumors. These findings suggested that the expression status of EMT-related transcription factors might play an important role in the implantation of metastatic foci.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is a key step of the progression of tumor cell metastasis. Recent work has demonstrated some miRNAs play critical roles in EMT. In this study, we focused on the roles of miR-300 in regulating EMT. METHODS: The expression levels of miR-300 were examined in epithelial carcinoma cells that underwent an EMT using quantitative reverse transcription-PCR. The role of miR-300 in EMT was investigated by transfection of the miR-300 mimic or inhibitor in natural epithelial-mesenchymal phenotype cell line pairs and in transforming growth factor (TGF) beta-induced EMT cell models. A luciferase reporter assay and a rescue experiment were conducted to confirm the target gene of miR-300. The efficacy of miR-300 against tumor invasion and metastasis was evaluated both in vitro and in vivo. Correlation analysis between miR-300 expression and the expression levels of its target gene, as well as tumor metastasis was performed in specimens from patients with head and neck squamous cell carcinoma (HNSCC). RESULTS: MiR-300 was found down-regulated in the HNSCC cells and breast cancer cells that underwent EMT. Ectopic expression of miR-300 effectively blocked TGF-beta-induced EMT and reversed the phenotype of EMT in HN-12 and MDA-MB-231 cells, but inhibition of miR-300 in the epithelial phenotype cells, HN-4 and MCF-7 cells, could induce EMT. The luciferase reporter assay and the rescue assay results showed that miR-300 directly targets the 3'UTR of Twist. Enforced miR-300 expression suppressed cell invasion in vitro and experimental metastasis in vivo. Clinically, miR-300 expression was found inversely correlated with Twist expression and reduced miR-300 was associated with metastasis in patient specimens. CONCLUSIONS: Down-regulation of miR-300 is required for EMT initiation and maintenance. MiR-300 may negatively regulate EMT by direct targeting Twist and therefore inhibit cancer cell invasion and metastasis, which implicates miR-300 as an attractive candidate for cancer therapy.

The transcription factor Twist plays a key role in cancer metastasis. The present study aimed at investigating clinical Twist expression in patients with esophageal squamous cell carcinoma (ESCC) in order to correlate the Twist levels with the patients' survival rates and their other clinical parameters. Immunohistochemical staining using polyclonal Twist antibody was performed on paraffin embedded specimens of 112 ESCC patients and non-neoplastic esophageal epithelium used as a control. The overall staining intensity was analyzed along with clinicopathologic data and prognosis of ESCC. Twist expression was significantly higher in ESCC than in non-neoplastic oesophageal epithelium (P < 0.001). The Twist expression directly correlated with distant metastasis after esophagectomy (P = 0.001). Kaplan-Meier estimate in conjunction with the log-rank test revealed an inverse proportion relationship between postoperative survival rates of the patients and their Twist expression levels (log-rank, P < 0.001). In addition, Cox mono-variate analysis revealed that T/N classification, pTNM stage, distant metastasis and Twist expression were significantly correlated with mortality risk of patients after operation (P < 0.05). By Cox multi-variate analysis, Twist expression (risk ratio = 2.394; P < 0.001) and N classification were identified as the independent prognostic factors of patient survival. In conclusion, upregulated Twist expression in the primary ESCC significantly correlates with the high risk of subsequent development of distant metastasis and low postoperative survival rates; the latter was not significantly correlated with patients' age, gender, tumor location and differentiation. Twist may serve as an independent prognostic marker for predicting development of distant metastasis in ESCC patients and their survival.

BACKGROUND: Epithelial-mesenchymal transition has recently attracted great attention in studying the malignant progression of cells through a converging pathway of oncogenesis and metastasis. Twist1 and Mastermind-like 1 (MAML1) are major regulators of EMT through different pathways. The aim of this study was to investigate the clinicopathological relevance of the expression of MAML-1 and Twist1 genes in esophageal squamous cell carcinoma (ESCC). METHODS: tumoral and corresponding normal tissues from 55 treatment-naive ESCC patients were subjected for expression analysis with quantitative real-time RT-PCR. RESULTS: Overexpression of MAML-1 and Twist1 were significantly associated with lymph node metastasis and the surgical staging of tumor. Overexpression of Twist1 was associated with tumor depth of invasion. Mean relative expression (MRE) of MAML1 was significantly higher in patients with metastasis to lymph nodes (3.07 +/- 0.51 vs. 0.86 +/- 0.58, P = .008). MRE of Twist1 was significantly higher in patients with invasion of tumor to adventitia (T3, T4) (1.97 +/- 0.29 vs. 0.39 +/- 0.73, P = .036). In advanced stages of tumor (stage III, IV), a significantly higher MRE of Twist1 (2.47 +/- 0.41 vs. 1.25 +/- 0.36, P = .035) and MAML1 (3.05 +/- 0.45 vs. 1.07 +/- 0.59, P = .021) mRNA was observed. CONCLUSIONS: We introduce Twist1 and MAML1 as new molecular markers of advanced tumor, which determine the characteristics and aggressive behavior of ESCC. Along with the emerging evidence of their role in different cellular processes and aberrations in various cancers, they are suggested as potentially interesting therapeutic targets to reverse a broad spectrum of functional aberrations that promote ESCC development.

We have investigated mRNA and protein expression of TWIST, Vimentin and E-cadherin in ESCC (oesophageal squamous cell carcinoma) and explored their relationship with tumour's infiltration and metastasis. RT-PCR (reverse transcriptase-PCR) was used to evaluate mRNA expression of TWIST, E-cadherin and Vimentin in 40 cases of ESCC. The protein expression of the genes was examined by immunohistochemical staining in each specimen. expression of TWIST, E-cadherin and Vimentin mRNA and protein with clinicopathologic parameters were analysed. mRNAs of TWIST, Vimentin and E-cadherin were expressed in 75, 55 and 35% respectively of ESCC, i.e. significantly different from that in normal oesophageal mucosa (15, 0 and 85% respectively; P<0.01). In ESCC with LN (lymph node) metastasis, expression of TWIST and Vimentin mRNA, but not E-cadherin mRNA was significantly higher (100 and 83%) than in ESCC without LN metastasis (64 and 43%, P=0.018) respectively. Levels of mRNA expression of the 3 genes followed similar patterns to their above-mentioned frequencies. Protein expression of TWIST, E-cadherin and Vimentin were observed in 70, 35 and 50% respectively of ESCC, which were significantly different from normal mucosa (15, 80 and 0%; P<0.001). In ESCC with LN metastasis, protein expression of TWIST and Vimentin, but not E-cadherin, were significantly higher (100 and 75%) than in ESCC without LN metastasis (61 and 39%). Protein expression of TWIST was positively correlated with Vimentin (r=0.327, P=0.039), but negatively correlated with E-cadherin (r= -0.633, P=0.000). Thus, both mRNAs and proteins of TWIST and Vimentin were significantly overexpressed in ESCC, especially ESCC with LN metastasis. The mRNA and protein of E-cadherin were down-regulated in ESCC. These results suggest potential roles of TWIST as the promoter of tumour invasion and metastasis associated with down-regulation of E-cadherin.

This study aimed to investigate the expression of Twist in gastric cancer tissues and its correlation between Twist and the epithelial-mesenchymal transition (EMT). By means of RT-PCR and Western blot, the mRNA and protein expressions of Twist, E-cadherin, and Vimentin in 61 gastric cancer tissues and adjacent normal tissues were detected. The positive rates of Twist, E-cadherin, and Vimentin mRNA expression in gastric cancer tissues were 73.9. 40.6, and 60.9 %, respectively; compared to the expression of these genes in adjacent normal tissues (2.9, 75.4, and 27.5 %), the differences were significant (p < 0.05). The E-cadherin protein expression level in gastric cancer tissues was significantly lower than that in the adjacent normal tissues (p < 0.05). After the transfection of Twist siRNA into the MKN45 cells, the protein expression of Twist was significantly reduced (p < 0.05), the protein expression of E-cadherin was significantly increased, and the number of cells that passed through the Transwell chamber was significantly lower than that in the non-transfected control group as well as the transfected control group (p < 0.05). Twist may be associated with the epithelial-mesenchymal transition in gastric cancer and the tumorigenesis, invasion, and metastasis of gastric cancer.

Trefoil factor 3 (TFF3) is a member of the TFF-domain peptide family and essential in regulating cell migration and maintaining mucosal integrity in gastrointestinal tract. However, the role of TFF3 and its downstream regulating mechanisms in cancer cell migration remain unclear. We previously reported that TFF3 prolonged the up-regulation of Twist protein to modulate IL-8 secretion in intestinal epithelial cells. In this study, we investigated the role of Twist protein in TFF3-induced migration of SGC7901 cells. While Twist was activated by TFF3, siRNA-mediated knockdown of Twist abolished TFF3-induced cell migration. Furthermore, the migration related marker CK-8 as well as ZO-1 and MMP-9 was also regulated by TFF3 via a Twist-dependent mechanism. Our study suggests that Twist, as an important potential downstream effector, plays a key role in TFF3-modulated metastasis in gastric cancer and can be a promising therapeutic target against intestinal-type gastric cancer.

BACKGROUND: Twist, a basic helix-loop-helix transcription factor, has been reported to play a key role in the metastatic progression of several types of cancer. AIMS: To investigate the expression and clinical significance of Twist, E-cadherin, and N-cadherin in gastrointestinal stromal tumors (GISTs). METHODS: The expression of Twist, E-cadherin, and N-cadherin in GISTs was determined by immunohistochemistry, and their relationship with clinicopathological characteristics was analyzed. RESULTS: The positive rates of Twist, E-cadherin, and N-cadherin in GISTs were 66.7 % (52/78), 35.9 % (28/78), and 75.6 % (59/78), respectively. Twist was expressed significantly more in GISTs with distant metastasis or local invasion (p < 0.05). Although E-cadherin was expressed significantly less in cases of GISTs with distant metastasis (p < 0.05), expression of N-cadherin did not differ significantly according to clinical and pathological characteristics (p > 0.05). expression of Twist was correlated positively with E-cadherin (rs = -0.253, p = 0.026) and negatively with N-cadherin (rs = 0.245, p = 0.030). CONCLUSIONS: Twist was expressed significantly more and E-cadherin significantly less in GISTs with metastasis, and expression of both was closely related to metastasis of GISTs.

Hepatocellular carcinoma (HCC) is a highly invasive tumor characterized by vigorous neovascularization. The purpose of this study is to examine the expression of Twist, a highly conserved bHLH transcription factor that is known to promote EMT, and evaluate its effect on tumor angiogenesis and metastasis of HCC. The mRNA expression of Twist, VEGF, E-cadherin, and N-cadherin was determined by Real-Time RT-PCR in 30 pairs of hepatocellular carcinomas and matched non-cancerous tissues. Immunohistochemistry was carried out to analyze the protein expression of Twist, VEGF, E-cadherin, and N-cadherin in 40 hepatocellular carcinoma cases. The staining of endothelial cells for CD34 was used to evaluate the MVD. We found that Twist mRNA and protein were both increased in HCC as compared to non-cancerous tissues. The HCC specimens showing positive Twist expression had a higher microvessel density than those without Twist expression. And up-regulated Twist protein was significantly associated with intrahepatic and extrahepatic metastasis (p=0.048 and P=0.039 respectively). In addition, patients with Twist expression had poor prognosis. We also found that the expression of Twist positively correlated with up-regulation of VEGF and N-cadherin (P=0.002 and p=0.016 respectively), but not with downregulation of E-cadherin in HCC. Our results demonstrate that Twist may play an important role in the angiogenesis and metastasis of HCC. Twist expression may become a potential novel prognostic factor for the disease survival of HCC.

The epithelial-mesenchymal transition regulator Twist1 has been implicated in tumor invasion, metastasis, and vasculogenic mimicry formation of human hepatocellular carcinoma. However, the relationship between Twist1 expression and endothelium-dependent angiogenesis is not clear. In this study, to investigate the role of Twist1 in hepatocellular carcinoma angiogenesis, we measured the microvessel density by CD31 immunohistochemistry stain and explored the microvessel density as an angiogenesis indicator. The microvessel density in paraffin sections from 97 patients was correlated with Twist1 expression up-regulation. Nuclear relocation was also identified based on immunohistochemistry stain, presenting a significant clinical pattern in hepatocellular carcinoma metastasis and prognosis. Twist1 expression, which is both located in the cytoplasm and relocated into the nucleus, was associated with matrix metalloproteinase 9 up-regulation; matrix metalloproteinase 2 did not appear to present these effects in hepatocellular carcinoma. An assessment of microvessel density could provide an estimate of the degree of angiogenic activity in tissues, as well as its association with Twist1 up-regulated expression. To the best of our knowledge, not only is Twist1 related to metastasis by tumor cells, but vasculogenic mimicry is also significantly related to microvessel density; this process is also associated with matrix metalloproteinase 9 up-regulated expression. This work provides a better understanding of the role of Twist1 in hepatocellular carcinoma angiogenesis and metastasis, suggesting that our findings could represent tumor cell epithelial-mesenchymal transition and endothelium-dependent angiogenesis, as can be seen in hepatocellular carcinoma.

BACKGROUND: To examine the expression of signal transducer and activator of transcription 3 (STAT3) and its activated form (p-STAT3), Twist, and E-cadherin in hepatocellular carcinoma (HCC), and explore their correlations with HCC progression and prognosis. MATERIALS AND METHODS: The expression profiles of STAT3, p-STAT3, Twist, and E-cadherin were assessed on 100 clinical HCC samples and 10 normal liver tissues by using an immunohistochemical staining method, and their correlations with clinicopathologic parameters and survival of HCC patients were statistically analyzed. RESULTS: The results demonstrated that the positive rate of STAT3, p-STAT3, and Twist in HCC was significantly higher than that in normal liver tissues; furthermore, 52% of HCC lesions showed reduced E-cadherin expression. Correlation analysis indicated that p-STAT3 was positively correlated with Twist expression, whereas Twist was negatively correlated with E-cadherin expression; p-STAT3, Twist, or E-cadherin expression was significantly associated with HCC invasion and metastasis. Survival analysis showed that HCC patients with p-STAT3, Twist positive expression, or reduced E-cadherin expression had a significantly shorter survival duration than those with p-STAT3, Twist negative expression, or those with normal E-cadherin expression. Multivariate analysis identified p-STAT3, Twist, or E-cadherin expression as an independent prognostic factor for overall survival of HCC patients after surgery. CONCLUSIONS: By this study, we suggest that activated STAT3 signal may associate with Twist and E-cadherin expression and mediate HCC invasiveness and metastasis; abnormal p-STAT3/Twist/E-cadherin signal axis may predict poor prognosis of HCC patients.

The antiapoptotic protein Bcl-2 plays multiple roles in apoptosis, immunity, and autophagy. Its expression in tumors correlates with tumor grade and malignancy. The recapitulation of the normal developmental process of epithelial-mesenchymal transition (EMT) contributes to tumor cell plasticity. This process is also a characteristic of metastatic cells and vasculogenic mimicry. In the present study we report functional and structural interactions between Bcl-2 and the EMT-regulating transcription factor Twist1 and the relationship with metastasis and vascular mimicry. Bcl-2 and Twist1 are coexpressed under hypoxia conditions. The Bcl-2 can bind to Twist1 in vivo and in vitro. This interaction involves basic helix-loop-helix DNA binding domain within Twist1 and through two separate domains within Bcl-2 protein. Formation of the Bcl-2/Twist1 complex facilitates the nuclear transport of Twist1 and leads to transcriptional activation of wide ranges of genes that can increase the tumor cell plasticity, metastasis, and vasculogenic mimicry. Finally, nuclear expression of Bcl-2 and Twist1 is correlated with poor survival of these patients in a cohort of 97 cases of human hepatocellular carcinoma. CONCLUSION: The results describe a novel function of Bcl-2 in EMT induction, provide insight into tumor progression, and implicate the Bcl-2/Twist1 complex as a potential target for developing chemotherapeutics.

The epithelial-mesenchymal transition (EMT) converts epithelial tumor cells into invasive and metastatic cancer cells, leading to mortality in cancer patients. Although TWIST is a master regulator of EMT and metastasis for breast and other cancers, the mechanisms responsible for TWIST-mediated gene transcription remain unknown. In this study, purification and characterization of the TWIST protein complex revealed that TWIST interacts with several components of the Mi2/nucleosome remodeling and deacetylase (Mi2/NuRD) complex, MTA2, RbAp46, Mi2 and HDAC2, and recruits them to the proximal regions of the E-cadherin promoter for transcriptional repression. Depletion of these TWIST complex components from cancer cell lines that depend on TWIST for metastasis efficiently suppresses cell migration and invasion in culture and lung metastasis in mice. These findings not only provide novel mechanistic and functional links between TWIST and the Mi2/NuRD complex but also establish new essential roles for the components of Mi2/NuRD complex in cancer metastasis.

Epithelial-mesenchymal transition (EMT), which involves the persistent loss of epithelial markers and expression of mesenchymal markers, is assumed to have a critical role in not only tissue development during embryogenesis but also central mechanisms that enhance the invasive and metastatic ability of cancer cells. Twist has been identified to play an essential role in EMT-mediated tumor invasion and metastasis. Although recent studies suggest that twist expression levels in tissue specimens of lung cancer might be associated with prognosis, the expression of twist in lung cancer cells itself and its effect have not been fully evaluated. Here, we evaluated twist expression and its effect on phenotype alteration in lung cancer cell lines. Twist expression varied among human lung cancer cell lines. The lung cancer cell lines with high twist expression also tended to show a high vimentin/E-cadherin ratio, which was supported by a migration assay, in which high twist expression gave rise to high cell motility. Furthermore, in comparison to control cells, the lung cancer cells with ectopic expression of twist showed a significant phenotype alteration through EMT and an increasing ability to migrate in vitro, in part, due to a tenfold increase in matrix metalloproteinases activity and almost a 60% increase in modulation of focal adhesion kinase activity, although a contribution of microRNA appeared unlikely in our study. Our present analysis of twist expression in lung cancer provide clues to comprehensive understanding of the mechanisms, by which metastasis often develops in lung cancer.

tumor cells often use developmental processes to progress toward advanced disease. The E-box transcription factor TWIST1 is essential to epithelial-mesenchymal transition (EMT) and cell migration in the developing neural crest. In melanoma, which derives from the neural crest cell lineage, enhanced TWIST1 expression has been linked to worse clinical prognosis. However, mechanisms underlying TWIST1 expression and whether aberrant TWIST1 levels promote steps in melanoma progression remain unknown. Here, we report that elevated TWIST1 mRNA/protein expression is dependent on extracellular signal-regulated kinase (ERK)1/2 signaling, which is hyperactive in the majority of melanomas. We show that TWIST1 protein levels are especially high in melanoma cell lines generated from invasive, premetastatic stage tumors. Furthermore, TWIST1 expression is required and sufficient to promote invasion through Matrigel and spheroid outgrowth in three-dimensional dermal-mimetic conditions. Alterations to spheroid outgrowth were not as a result of altered cell death, cell-cycle profile, or paradigm EMT protein changes. Importantly, we identify matrix metalloproteinase-1 (MMP-1) as a novel downstream target of TWIST1. We have determined that TWIST1 acts, in a dose-dependent manner, as a mediator between hyperactive ERK1/2 signaling and regulation of MMP-1 transcription. Together, these studies mechanistically show a previously unrecognized interplay between ERK1/2, TWIST1, and MMP-1 that is likely significant in the progression of melanoma toward metastasis.

Melanoma patients frequently have elevated serum levels of interleukin-6 (IL-6), which is correlated with a poor prognosis. IL-6 activates STAT3 phosphorylation, inducing the transcription of genes that regulate tumor cell proliferation and antiapoptosis. In addition, recent evidence suggests that IL-6 induces the epithelial-to-mesenchymal transition and enhances the invasiveness of tumor cells of epithelial origin. However, it is unknown whether IL-6 affects mesenchymal tumor cells. In this study, we examined the effects of IL-6 on melanoma cells and found that IL-6 can enhance their metastatic potential by regulating the expression of Twist and N-cadherin. First, we confirmed that human melanoma tissues express IL-6 (especially at the lesion site), the IL-6 receptor, N-cadherin, and nuclear Twist. Next, we found that IL-6 induces STAT3 phosphorylation in WM-266-4 human melanoma cells, resulting in transient upregulation of Twist, which is a key regulator of metastasis. Importantly, the expression of N-cadherin, a protein downstream of Twist, was also increased on the cell surface after treatment with IL-6. These cells showed enhanced invasiveness, assessed using an invasion assay, and formed more metastatic nodules in the lungs of NOD-SCID mice after an intravenous injection. Importantly, melanoma cells with knocked-down N-cadherin formed less lung nodules compared with control in the NOD-SCID mouse model. Our data suggest that increased serum IL-6 in cancer patients could increase the invasiveness of melanoma cells and accelerate metastasis. Blocking IL-6 in the melanoma microenvironment may therefore inhibit disease progression.

metastasis is a multistep process during which cancer cells disseminate from the site of primary tumors and establish secondary tumors in distant organs. In a search for key regulators of metastasis in a murine breast tumor model, we have found that the transcription factor Twist, a master regulator of embryonic morphogenesis, plays an essential role in metastasis. Suppression of Twist expression in highly metastatic mammary carcinoma cells specifically inhibits their ability to metastasize from the mammary gland to the lung. Ectopic expression of Twist results in loss of E-cadherin-mediated cell-cell adhesion, activation of mesenchymal markers, and induction of cell motility, suggesting that Twist contributes to metastasis by promoting an epithelial-mesenchymal transition (EMT). In human breast cancers, high level of Twist expression is correlated with invasive lobular carcinoma, a highly infiltrating tumor type associated with loss of E-cadherin expression. These results establish a mechanistic link between Twist, EMT, and tumor metastasis.

Stabilization of the hypoxia-inducible factor-1alpha (HIF-1alpha) transcription complex, caused by intratumoural hypoxia, promotes tumour progression and metastasis, leading to treatment failure and mortality in different types of human cancers. The transcription factor TWIST is a master regulator of gastrulation and mesoderm-specification and was implicated recently as an essential mediator of cancer metastasis. Notably, HIF-1alpha- and TWIST-null mice show similarities in their phenotypes. Here, we have shown that hypoxia or overexpression of HIF-1alpha promotes epithelial-mesenchymal transition (EMT) and metastastic phenotypes. We also found that HIF-1 regulates the expression of TWIST by binding directly to the hypoxia-response element (HRE) in the TWIST proximal promoter. However, siRNA-mediated repression of TWIST in HIF-1alpha-overexpressing or hypoxic cells reversed EMT and metastastic phenotypes. Co-expression of HIF-1alpha, TWIST and Snail in primary tumours of patients with head and neck cancers correlated with metastasis and the worst prognosis. These results provide evidence of a key signalling pathway involving HIF-1alpha and TWIST that promotes metastasis in response to intratumoural hypoxia.

Twist1 and Twist2 are major regulators of embryogenesis. Twist1 has been shown to favor the metastatic dissemination of cancer cells through its ability to induce an epithelial-mesenchymal transition (EMT). Here, we show that a large fraction of human cancers overexpress Twist1 and/or Twist2. Both proteins override oncogene-induced premature senescence by abrogating key regulators of the p53- and Rb-dependent pathways. Twist1 and Twist2 cooperate with Ras to transform mouse embryonic fibroblasts. Interestingly, in epithelial cells, the oncogenic cooperation between Twist proteins and activated mitogenic oncoproteins, such as Ras or ErbB2, leads to complete EMT. These findings suggest an unanticipated direct link between early escape from failsafe programs and the acquisition of invasive features by cancer cells.

The Twist1 transcription factor is known to promote tumor metastasis and induce Epithelial-Mesenchymal Transition (EMT). Here, we report that Twist1 is capable of promoting the formation of invadopodia, specialized membrane protrusions for extracellular matrix degradation. Twist1 induces PDGFRalpha expression, which in turn activates Src, to promote invadopodia formation. We show that Twist1 and PDGFRalpha are central mediators of invadopodia formation in response to various EMT-inducing signals. Induction of PDGFRalpha and invadopodia is essential for Twist1 to promote tumor metastasis. Consistent with PDGFRalpha being a direct transcriptional target of Twist1, coexpression of Twist1 and PDGFRalpha predicts poor survival in breast tumor patients. Therefore, invadopodia-mediated matrix degradation is a key function of Twist1 in promoting tumor metastasis.

Proinflammatory cytokines produced in the tumor microenvironment facilitate tumor development and metastatic progression. In particular, TNF-alpha promotes cancer invasion and angiogenesis associated with epithelial-mesenchymal transition (EMT); however, the mechanisms underlying its induction of EMT in cancer cells remain unclear. Here we show that EMT and cancer stemness properties induced by chronic treatment with TNF-alpha are mediated by the upregulation of the transcriptional repressor Twist1. Exposure to TNF-alpha rapidly induced Twist1 mRNA and protein expression in normal breast epithelial and breast cancer cells. Both IKK-beta and NF-kappaB p65 were required for TNF-alpha-induced expression of Twist1, suggesting the involvement of canonical NF-kappaB signaling. In support of this likelihood, we defined a functional NF-kappaB-binding site in the Twist1 promoter, and overexpression of p65 was sufficient to induce transcriptional upregulation of Twist1 along with EMT in mammary epithelial cells. Conversely, suppressing Twist1 expression abrogated p65-induced cell migration, invasion, EMT, and stemness properties, establishing that Twist1 is required for NF-kappaB to induce these aggressive phenotypes in breast cancer cells. Taken together, our results establish a signaling axis through which the tumor microenvironment elicits Twist1 expression to promote cancer metastasis. We suggest that targeting NF-kappaB-mediated Twist1 upregulation may offer an effective a therapeutic strategy for breast cancer treatment.

OBJECTIVE: To investigate the expression of Twist1 and MMP-2 protein and their significance in endometrial endometrioid adenocarcinoma. METHODS: The expression of Twist1 and MMP-2 protein in 70 cases of endometrial endometrioid adenocarcinoma was detected on tissue chips using immunohistochemical staining. RESULTS: The positive rates of Twist1 and MMP-2 protein expression were 65.7% and 67.1%, respectively. Both of the high expressions of Twist1 and MMP-2 were positively correlated with FIGO staging and tumor myometrial invasion (P < 0.05, respectively). Also the high expression of Twist1 was positively correlated with ovarian metastasis and the expression of MMP-2 was positively correlated with tumor grading (P < 0.05). The patients overall survival and relapse-free survival in the group of high Twist1 expression were shorter than that in the group of low Twist1 expression (P < 0.05). The expression of MMP-2 was positively correlated with Twist1 expression (P < 0.01, respectively). CONCLUSIONS: The expression of Twist1 may be closely correlated with the tumor invasion, metastasis and prognosis in patients with endometrial endometrioid adenocarcinoma. The expression of Twist1 has a close relationship with MMP-2 in endometrial endometrioid adenocarcinoma.

Basic helix-loop-helix (bHLH) transcription factor Twist is one of the key inducers of epithelial to mesenchymal transition (EMT) that is a transdifferentiation program associated with embryo development and tumor metastasis. High level of Twist expression is shown to be correlated with cancer malignancy. Although Twist has been reported to be degraded by F-box and leucine-rich repeat protein 14 (FBXL14), the molecular mechanisms by which Twist levels are regulated have not been fully elucidated. In the present study, we identified Twist to be a ubiquitin substrate of beta-transducin repeat-containing protein (beta-TRCP), the adaptor subunit of SCF(beta-TRCP) (Skp1-Cul1-F-box protein) E3 ligase complex. We observed that depletion of beta-TRCP leads to an accumulation of Twist protein, which could enhance tumor cell motility and cancer metastasis. Moreover, phosphorylation of Twist by inhibitor of KappaB kinase beta (IKKbeta) at multiple sites triggers its cytoplasmic translocation and the destruction by SCF(beta-TRCP). Thus, our results provide the potential molecular mechanism of how the mesenchymal marker Twist is degraded, thereby shedding lights into regulation of the EMT, and providing the rationale for development of new therapeutic intervention to achieve better treatment outcomes in human cancer.

The epithelial-to-mesenchymal transient (EMT) is associated with tumor metastasis. Twist is one of the key transcription factors for EMT and relates to tumor cell migration. Long non-coding RNAs (lncRNAs) have recently emerged as important regulatory molecules involved in a broad range of biological processes and complicated diseases. However, it is unknown whether a signal network and lncRNAs are involved in Twist-induced EMT program. Taking MCF10A/Twist as a model, more than 99 lncRNAs and 3164 genes are regulated in the Twist-induced EMT process using lncRNA-array and cDNA micro-array. We establish a downstream signal network associated with EMT induced by Twist using bioinformatic analysis (Gene Ontology, pathway analysis) and experimental data. A set of multiple canonical signal pathways (such as WNT, MAPK, JAK/STAT, TGF-beta, mTOR, Hedgehog and P53 signaling pathways) and several lncRNAs [such as lncRNA (chr6, 26124411-26139312, +), lncRNA (chr1, 41944445-41949874, -), lncRNA (chr17, 44833874-44834830, +)] are altered in MCF10A/Twist cells. More interestingly, lncRNA (chr17, 44833874-44834830, +), lncRNA (chr17, 21142183-21156578, -), lncRNA (chr6, 26124411-26139312, +) and lncRNA (chr19, 438420-2083745, -) may be involved in regulation or activation of WNT signaling pathway in the Twist-induced EMT process. These findings first determine that Twist contributes to invasion and metastasis by inducing wide-ranging transcriptional and functional changes of lncRNAs and signal pathways in our study.

The present study was aimed to determine twist expression in nasopharyngeal carcinoma (NPC) and to investigate the clinicopathological significance in the progress of NPC. Semiquantitative RT-PCR and Western blotting were carried out to investigate the expression of Twist in NPC cell lines and normal nasopharyngeal epithelial cell line, which showed that both Twist mRNA and protein were up-regulated in the tumor cells in comparison with the normal cells. We then examined Twist mRNA expression in non-cancerous nasopharyngeal mucosa (10 cases) and NPC (95 cases) using in situ hybridization. The results showed that Twist was overexpressed in 59 of 95 (62.1%) NPC samples. In contrast, there was no obvious expression of Twist mRNA in non-cancerous tissues. In addition, another 75 NPC samples were analyzed by immunohistochemistry, and 33 of the 75 samples were shown to be positive for Twist protein. Both Twist mRNA expression and Twist protein expression were positively associated with lymph-node metastasis and distant metastasis. Furthermore, expression of Twist protein was correlated with the NPC prognosis. Patients with NPC who were Twist protein-positive had a worse 5-year survival rate. These findings demonstrate that the Twist may play an important role in the invasion and metastasis of NPC. Twist protein is valuable marker for assessing the prognosis of NPC.

Nasopharyngeal carcinoma (NPC), an EBV-associated malignancy, is highly metastatic compared with other head and neck tumors, perhaps because of its viral link. Here, we show that the principal EBV oncoprotein, latent membrane protein 1 (LMP1), induces epithelial-mesenchymal transition (EMT) via Twist, a master transcriptional regulator in embryogenesis and newly implicated in metastasis, which, in turn, are likely to contribute to the highly metastatic character of NPC. LMP1 could induce EMT and its associated cell motility and invasiveness in a cell culture model, whereas expression of Twist small interfering RNA reversed LMP1-induced EMT. In diverse EBV-infected cell lines, expression of Twist correlates with expression of LMP1. Dominant-negative LMP1 could suppress Twist expression in EBV-positive cells, whereas LMP1 could induce Twist in EBV-negative nasopharyngeal cells. LMP1 signals through the nuclear factor-kappaB pathway, and an IkappaB superrepressor inhibited induction of Twist by LMP1. Finally, in human NPC tissues, expression of Twist and LMP1 is directly correlated and expression of Twist is associated with metastasis clinically. These results suggest that induction of Twist by a human viral oncoprotein LMP1 directly contributes to the metastatic nature of NPC.

PURPOSE: To investigate the protein expression of Twist, Snail, and Slug in oral squamous cell carcinoma (OSCC) samples and evaluate the potential correlation between the expression status and clinicopathologic features in patients with OSCC. PATIENTS AND METHODS: Twist, Snail, and Slug protein expression was assessed by immunohistochemistry in a total of 60 OSCC samples and 10 normal oral mucosal samples. The associations between the protein expression and clinicopathologic parameters were mainly detected using the chi(2) test. The survival analysis was performed using the Kaplan-Meier method, and the prognostic analysis was performed using Cox regression models. RESULTS: Immunohistochemistry stain analysis showed that positive Twist, Snail, and Slug protein expression was observed in 70%, 63.3%, and 58.3% of the cases, respectively. Twist protein expression was positively associated with lymph node metastasis, pathologic grade, and tumor stage (P = .012, P = .008, and P = .004, respectively, chi(2) test). All patients were followed up for 6 to 59 months (mean 37). A correlation between Twist protein expression and tumor recurrence was detected (log-rank test, P = .025). Nevertheless, no correlation was found between the Snail and Slug protein expression and the clinicopathologic parameters. CONCLUSIONS: Twist might serve as a useful molecular marker for lymph node metastasis and a poor prognosis in OSCC.

Twist, a basic helix-loop-helix transcription factor, and E-cadherin are both correlated with the metastatic progression of several types of cancer. However, it is currently unknown whether their activations have relevance to the progression of osteosarcoma. The purpose of the present study was to investigate the clinicopathological and prognostic value of Twist and E-cadherin in osteosarcoma. Twist and E-cadherin expressions were determined by immunohistochemistry. Patient survival rates were determined by Kaplan-Meier method and log-rank test. Cox regression was adopted for multivariate analysis of prognostic factors. The positive rates of Twist and E-cadherin in 107 osteosarcoma specimens were 31.8 % (34/107) and 20.6 % (22/107), respectively. Twist expression was significantly correlated with that of E-cadherin (r = -0.209, P = 0.031). The positive expression of Twist and E-cadherin was significantly associated with metastasis in 107 osteosarcoma specimens (both P < 0.05). Patients with positive Twist expression had significantly poorer overall survival (OS; P < 0.05) and disease-free survival (DFS, P < 0.05) when compared with patients with the negative expression of Twist. Patients with positive expression of E-cadherin had significantly poorer OS (P < 0.05) when compared with patients with negative E-cadherin expression, but not a significantly poorer DFS (P = 0.081). On multivariate analysis, Twist expression and age were found to be independent prognostic factors for OS (both P < 0.05) and DFS (both P < 0.05). Our results suggest that Twist was expressed significantly more and E-cadherin significantly less in osteosarcoma with metastasis, and expression of both might be related to the prediction of metastasis potency and poor prognosis for patients with osteosarcoma.

PURPOSE: This study aimed to explore the role of the Twist gene in the epithelial-mesenchymal transition of ovarian cancer. METHODS: An RNA interference plasmid expressing a small interfering RNA (siRNA)-targeting Twist (Twist siRNA vector) was designed, constructed, and transfected into the human ovarian cancer cell line A2780. Transfection efficiency was assessed under a fluorescence microscope. Changes in the expression of Twist mRNA in A2780 after transfection with the pGenesil Twist shRNA plasmid were analyzed through RT-PCR. MTT assays and adhesion experiments were applied to determine changes in proliferation and adhesion ability of A2870 after transfection with the Twist shRNA plasmid. Changes in the expression of the E-cadherin and N-cadherin proteins in A2780 after transfection with the Twist shRNA plasmid were analyzed using Western blotting. RESULT: The restructuring plasmid pGenesil-Twist shRNA was constructed successfully. After 48 h of culture, 80% of the cells expressed high-intensity GFP fluorescence and stability. The expression of Twist decreased significantly after the transfection of the Twist shRNA plasmid (P<0.05). Proliferation of the transfected Twist shRNA cells showed no difference with that of the A2780-nontransfection or A2780-si-control groups (P>0.05) but the adhesion ability of A2780 decreased dramatically (P<0.05). expression of the E-cadherin protein increased, whereas that of the N-cadherin protein decreased compared with that in the A2780-nontransfection or A2780- si-control groups (P<0.05). CONCLUSION: Twist is essential for epithelial-mesenchymal transition, invasion, and metastasis of ovarian cancer.

OBJECTIVE: To investigate the expression of Twist and E-cadherin in ovarian cancer tissues as well as the role of epithelial-mesenchymal transformation (EMT) in ovarian cancer metastasis. METHOD: The expressions of Twist and E-cadherin in 54 cases of ovarian cancer and paracancerous tissues were detected by Western blottin g and reverse transcriptase polymerase chain reaction. We used RNA interference to silence Twist expression in human ovarian cancer cell line, and detected E-cadherin expression using Western blotting. RESULTS: There was an increase in the relative abundance of Twist proteins and a decrease in E-cadherin in ovarian cancer compared with normal ovary tissues (P < 0.05). The expression levels of Twist and E-cadherin mRNA were 1.49 +/- 0.53 and 0.82 +/- 0.24 in ovarian cancer, and 1.14 +/- 0.38 and 1.08 +/- 0.19 in paracancerous tissues, respectively. The difference between the indicators in ovarian cancer and in paracancerous tissues was statistically significant (P < 0.05). When the Twist expression was silenced in an ovarian cancer cell line, the expression of the E-cadherin protein increased (P<0.05). CONCLUSION: The expression of Twist is upregulated, whereas that of E-cadherin is downregulated in ovarian cancer. EMT, mediated by Twist, may be correlated with ovarian cancer metastasis.

Androgen-independent metastatic prostate cancer is the main obstacle in the treatment of this cancer. Unlike a majority of solid cancers, prostate cancer usually shows poor response to chemotherapeutic drugs. In this study, we have shown a potential novel target, TWIST, a highly conserved bHLH transcription factor, in the treatment of prostate cancer. Using malignant and nonmalignant prostate tissues, we found that TWIST expression was highly expressed in the majority (90%) of prostate cancer tissues but only in a small percentage (6.7%) of benign prostate hyperplasia. In addition, the TWIST expression levels were positively correlated with Gleason grading and metastasis, indicating its role in the development and progression of prostate cancer. Furthermore, down-regulation of TWIST through small interfering RNA in androgen-independent prostate cancer cell lines, DU145 and PC3, resulted in increased sensitivity to the anticancer drug taxol-induced cell death which was associated with decreased Bcl/Bax ratio, leading to activation of the apoptosis pathway. More importantly, inactivation of TWIST suppressed migration and invasion abilities of androgen-independent prostate cancer cells, which was correlated with induction of E-cadherin expression as well as morphologic and molecular changes associated with mesenchymal to epithelial transition. These results were further confirmed on the androgen-dependent LNCaP cells ectopically expressing the TWIST protein. Our results have identified TWIST as a critical regulator of prostate cancer cell growth and suggest a potential therapeutic approach to inhibit the growth and metastasis of androgen-independent prostate cancer through inactivation of the TWIST gene.

AIM: Development of metastasis is one of the main causes of prostatic cancer-related death. We have previously found that up-regulation of TWIST, a highly conserved basic helix-loop-helix transcription factor, in prostatic cancer cells can promote epithelial to mesenchymal transition through down-regulation of E-cadherin. The present study aimed to investigate the prognostic significance of TWIST and to correlate TWIST and E-cadherin expression in prostatic cancer specimens. METHODS AND RESULTS: TWIST and E-cadherin expression was studied in 115 prostatic cancer specimens, eight cases of prostatic intraepithelial neoplasia and 37 cases of benign prostatic hyperplasia by immunohistochemistry. Increased cytoplasmic expression of TWIST was associated with malignant transformation of prostatic epithelium and histological progression of prostatic cancer, while nuclear TWIST expression was significant in predicting the metastatic potential of the primary prostatic cancer. In addition, high levels of TWIST expression were also significantly associated with aberrant E-cadherin expression. CONCLUSIONS: These results suggest that TWIST may serve as a prognostic marker for high-grade prostatic cancer. In addition, up-regulation of TWIST in combination with aberrant E-cadherin expression in primary prostatic cancer specimens may predict development of distal metastatic disease.

Twist1, a basic helix-loop-helix transcription factor, plays a key role during development and is a master regulator of the epithelial-mesenchymal transition (EMT) that promotes cancer metastasis. Structure-function relationships of Twist1 to cancer-related phenotypes are underappreciated, so we studied the requirement of the conserved Twist box domain for metastatic phenotypes in prostate cancer. Evidence suggests that Twist1 is overexpressed in clinical specimens and correlated with aggressive/metastatic disease. Therefore, we examined a transactivation mutant, Twist1-F191G, in prostate cancer cells using in vitro assays, which mimic various stages of metastasis. Twist1 overexpression led to elevated cytoskeletal stiffness and cell traction forces at the migratory edge of cells based on biophysical single-cell measurements. Twist1 conferred additional cellular properties associated with cancer cell metastasis including increased migration, invasion, anoikis resistance, and anchorage-independent growth. The Twist box mutant was defective for these Twist1 phenotypes in vitro. Importantly, we observed a high frequency of Twist1-induced metastatic lung tumors and extrathoracic metastases in vivo using the experimental lung metastasis assay. The Twist box was required for prostate cancer cells to colonize metastatic lung lesions and extrathoracic metastases. Comparative genomic profiling revealed transcriptional programs directed by the Twist box that were associated with cancer progression, such as Hoxa9. Mechanistically, Twist1 bound to the Hoxa9 promoter and positively regulated Hoxa9 expression in prostate cancer cells. Finally, Hoxa9 was important for Twist1-induced cellular phenotypes associated with metastasis. These data suggest that the Twist box domain is required for Twist1 transcriptional programs and prostate cancer metastasis. IMPLICATIONS: Targeting the Twist box domain of Twist1 may effectively limit prostate cancer metastatic potential.

BACKGROUND: Twist is a highly conserved epithelial-mesenchymal transcription factor that has been reported to be a key factor in tumor malignancy, including lymph node metastasis. It represents the major step of dissemination and serves as a chief prognostic indicator of disease progression. However, the mechanism by which Twist regulates lymph node metastasis remains incompletely understood. Studies on the mechanism of metastasis are thus required for determining appropriate therapeutic strategies. METHODS: Immunohistochemistry for lymphatic vessel endothelial receptor 1 (LYVE-1), Ki-67, Twist, vascular endothelial growth factor C (VEGF-C), and vascular endothelial growth factor receptor 3 (VEGFR-3) was performed to detect lymphatic vessel density (LVD), cell proliferation levels and the expressions of Twist, VEGF-C, and VEGFR-3 were determined from 66 primary supraglottic carcinoma tissue samples from 36 patients with lymph node metastasis (pathological N+, pN+) and 30 patients without metastasis (pathological N0, pN0). Western blotting analysis of the proteins in pN+ and pN0 primary tumors was used to characterize the expressions of Twist, VEGF-C, and VEGFR-3 further. RESULTS: The LVD was 22.4 +/- 10.3 in pN+ patients and 6.8 +/- 4.1 in pN0 ones. For Ki-67, the number of proliferous cells in pN+ patients was greater than that in pN0 ones. Both, however, were associated with their clinical nodal stages. In pN+ patients, Twist, VEGF-C, and VEGFR-3 expressions were 86.11% (31/36), 80.56% (29/36), and 58.33% (21/36), respectively. These values were higher than those found for pN0 patients (i.e., 13/30, 11/30, and 7/30, respectively) (P < 0.05). Among the samples with Twist expression, 88.64% were VEGF-C-positive and 59.09% were VEGFR-3-positive. The pN0 counterparts were 4.55% and 9.09%, respectively (P < 0.05). The expressions of Twist, VEGF-C, and VEGFR-3 in pN+ patients obtained through Western blotting analysis were significantly higher than those in pN0 patients, and the levels of VEGF-C and VEGFR-3 were positively correlated with that of Twist. CONCLUSIONS: Twist expression correlates with lymph node metastasis. The mechanism involved in such a correlation may be related to lymphangiogenesis.

This study aimed to examine HIF-2alpha, TWIST, and CXCR4 expression in papillary thyroid carcinoma (PTC) and assesses the association of their expression with clinicopathological indicators. HIF-2alpha, TWIST, and CXCR4 protein expression in 129 PTCs, 61 nodular hyperplasia, and 118 normal thyroid tissue specimens was analyzed using immunohistochemistry. The protein expression levels of these three molecules were upregulated in PTCs. High protein expression of HIF-2alpha, TWIST, and CXCR4 was significantly correlated with lymph node metastasis (LNM) (P < 0.001). Furthermore, HIF-2alpha, TWIST, and CXCR4 protein expression was correlated with one another. Concomitant high expression of these molecules had stronger correlation with LNM than did each alone (P = 0.032 for HIF-2alpha/TWIST, P < 0.001 for HIF-2alpha/CXCR4, P = 0.018 for TWIST/CXCR4, and P < 0.001 for HIF-2alpha/TWIST/CXCR4). Additionally, HIF-2alpha, TWIST, and CXCR4 mRNA expression were assessed in 30 PTCs, 10 nodular hyperplasia, and 10 normal thyroid tissue specimens using real-time RT-PCR. TWIST and CXCR4 mRNA expression levels were up-regulated in PTCs, and high mRNA expression of TWIST and CXCR4 was significantly correlated with LNM (P = 0.005 and P = 0.010, resp.). These results demonstrated that the evaluation of HIF-2alpha, TWIST, and CXCR4 expression in PTC may be useful in predicting the risk of LNM.

Although many researches have been undertaken to disclose the mechanisms of chemoresistance, the mechanisms remain unclear. The aim of this study is to elucidate the role of miR-181a-Twist1 pathway in the chemoresistance of tongue squamous cell carcinoma (TSCC). We found that cisplatin-induced chemoresistance in TSCC cell lines underwent EMT (epithelial-mesenchymal transition) and was accompanied by enhancing metastatic potential (migration and invasion in vitro), miR-181a downregulation and Twist1 upregulation. Functional analyses indicated that miR-181a reversed chemoresistance, inhibited EMT and metastatic potential in TSCC cells. Twist1 was confirmed as a direct miR-181a target gene by luciferase reporter gene assays. Twist1 knockdown by siRNA led to a reversal of the chemoresistance, inhibited EMT and metastatic potential in TSCC cells. Our study demonstrates that miR-181a-Twist1 pathway may play an important role in the development of cisplatin-chemoresistance, with EMT and an increase the metastatic potential of TSCC cells.