117581

TWIST2

The epithelial to mesenchymal transition (EMT) is a highly conserved cellular programme that has an important role in normal embryogenesis and in cancer invasion and metastasis. We report here that Twist2, a tissue-specific basic helix-loop-helix transcription factor, is overexpressed in human breast cancers and lymph node metastases. In mammary epithelial cells and breast cancer cells, ectopic overexpression of Twist2 results in morphological transformation, downregulation of epithelial markers and upregulation of mesenchymal markers. Moreover, Twist2 enhances the cell migration and colony-forming abilities of mammary epithelial cells and breast cancer cells in vitro and promotes tumour growth in vivo. Ectopic expression of Twist2 in mammary epithelial cells and breast cancer cells increases the size and number of their CD44(high)/CD24(low) stem-like cell sub-populations, promotes the expression of stem cell markers and enhances the self-renewal capabilities of stem-like cells. In addition, exogenous expression of Twist2 leads to constitutive activation of STAT3 (signal transducer and activator of transcription 3) and downregulation of E-cadherin. Thus, the overexpression of Twist2 may contribute to breast cancer progression by activating the EMT programme and enhancing the self-renewal of cancer stem-like cells.

BACKGROUND: Adenoid cystic carcinoma (ACC) of salivary gland is characterized by advanced local invasion and distant metastasis. Intratumoral hypoxia was reported to be associated with epithelial-mesenchymal transition (EMT) regulators. The purpose of this study was to evaluate the relationship between hypoxia-inducible factor (HIF)-2alpha, TWIST2, and SIP1 expression and the invasion and metastasis in ACC of salivary gland. METHOD: In vitro we first detected the expression of HIF-2alpha, TWIST2, and SIP1 in two ACC cell lines by Western blot and real-time RT-PCR. Then, in vivo, a retrospective investigation of 121 patients with ACC from Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University between 1996 and 2005 was carried out using immunohistochemistry to analyze the association between the expression of these three factors and clinical-pathological factors of patients. RESULTS: The protein and mRNA levels of HIF-2alpha, TWIST2, and SIP1 in the high-metastasis cell line (ACC-M) were much higher than those of the low-metastasis cell line (ACC-2). The positive expression of HIF-2alpha, TWIST2, and SIP1 (71.07%, 42.98%, and 38.02%, respectively) was associated with the perineural invasion, the local recurrence, and distant metastasis of patients with ACC (P < 0.05). The patients with the positive coexpression of the three factors had a lower survival rate than those with the negative expression (P < 0.05). CONCLUSION: It is proposed that the elevated expression of HIF-2alpha, TWIST2, and SIP1 can contribute to invasion and metastasis of ACC, and there might be some correlation between the hypoxia microenvironment and EMT in ACC.CI - (c) 2011 John Wiley & Sons A/S.

BACKGROUND: Twist2 has been shown to promote human tumor invasion as in breast cancer and cervical cancer. However, whether Twist2 promotes human ovarian cancer progression remains to be elucidated. Here, we investigate the role of Twist2 in ovarian cancer invasion and metastasis as well as the underlying molecular mechanisms. METHODS: Twist2 expression was detected by Immunohistochemistry (IHC) on tissue microarray of human ovarian cancers with scoring procedure according to the staining intensity and pattern. Twist2 gene was stably introduced into SKOV-3 ovarian cancer cells to examine the changes of cellular morphology, motility, invasiveness, and EMT molecular markers. RESULTS: Twist2 expression is significantly increased in ovarian cancers along with the FIGO disease stage, indicating that Twist2 may be associated with ovarian cancer metastasis. Overexpression of Twist2 induced the EMT phenotype including downregulation of E-cadherin, and upregulation of N-cadherin and beta-catenin in human ovarian cancer cells, suggesting that Twist2 might promote beta-catenin release from the E-cadherin/beta-catenin complex through inhibition of E-cadherin. Thus, beta-catenin degradation was inhibited due to inhibition of APC, and the Wnt/beta-catenin pathway was then activated by nuclear beta-catenin accumulation, which may activate transcription of downstream target genes to promote tumor invasion and metastasis. Collectively, these data indicated that beta-catenin is involved in Twist2-induced EMT in ovarian cancer. CONCLUSION: Our data indicates that upregulation of Twist2 is correlated with the FIGO stage in human ovarian cancers. In this report, we demonstrated that nuclear beta-catenin is accumulated in Twist2-induced EMT cells to facilitates ovarian cancer invasion and metastasis.

tumor budding in colorectal cancer is likened to an epithelial-mesenchymal transition (EMT) characterized predominantly by loss of E-cadherin and up-regulation of E-cadherin repressors like TWIST1 and TWIST2. Here we investigate a possible epigenetic link between TWIST proteins and the tumor budding phenotype. TWIST1 and TWIST2 promoter methylation and protein expression were investigated in six cell lines and further correlated with tumor budding in patient cohort 1 (n = 185). Patient cohort 2 (n = 112) was used to assess prognostic effects. Laser capture microdissection (LCM) of tumor epithelium and stroma from low- and high-grade budding cancers was performed. In colorectal cancers, TWIST1 and TWIST2 expression was essentially restricted to stromal cells. LCM results of a high-grade budding case show positive TWIST1 and TWIST2 stroma and no methylation, while the low-grade budding case was characterized by negative stroma and strong hypermethylation. TWIST1 stromal cell staining was associated with adverse features like more advanced pT (p = 0.0044), lymph node metastasis (p = 0.0301), lymphatic vessel invasion (p = 0.0373), perineural invasion (p = 0.0109) and worse overall survival time (p = 0.0226). Stromal cells may influence tumor budding in colorectal cancers through expression of TWIST1. Hypermethylation of the tumor stroma may represent an alternative mechanism for regulation of TWIST1.

Twist2, one of the basic helix-loop-helix protein (bHLH) family members, is responsible for the transcriptional regulation in mesenchymal cell lineages during its development. Twist2 functions as a molecular switch to activate or repress target genes by direct or indirect mechanisms. Twist2 can directly bind with conserved E-box on DNA sequence, to recruit co-activators or repressors, and interfere with the activation or inhibition function through protein-protein interactions with E-protein modulators. Nonsense mutations of Twist2 cause Setleis syndrome. Early research on Twist2 focused on osteogenesis, and then expression differences were found in a wide variety of tumors. Further studies showed that Twist2 plays an important role in cancer epithelial-mesenchymal transition (EMT). Regulation function of Twist2 is controlled by temporal and spatial expression, phosphorylation, dimerization and cell positioning adjustment. The involvement of Twist2 in a broad spectrum of regulatory pathways highlights the importance of understanding its role in normal development, homeostasis and disease. In this review, we summarize the role of Twist2 in osteogenesis differentiation, tumor formation and EMT, and its molecular mechanism. It is helpful to have a thorough understanding of the biological functions of Twist2, and facilitate the transformation and application in diagnosis, development and therapy.

BACKGROUND: epithelial-mesenchymal transition (EMT) is a dedifferentiation process that mainly involves in mesenchymal marker upregulation, epithelial maker downregulation and cell polarity loss. Related hypoxia factors play a crucial role in EMT, however, it remains few evidence to clarify the role of HIF-2alpha in EMT in pancreatic cancer. METHOD: In this study, we investigated the expression of HIF-2alpha and E-cadherin by immunohistochemistry in 70 pancreatic cancer patients, as well as the correlation to the clinicopathologic characteristics. Then we regulated the expression of HIF-2alpha in pancreatic cancer cells to examine the role of HIF-2alpha on invasion and migration in vitro. Finally, we tested the relation of HIF-2alpha and EMT related proteins by Western blot and determined whether HIF-2alpha regulated EMT through Twist regulating the expression of E-cadherin by Chromatin immunoprecipitation (ChIP) assay. RESULTS: We found that HIF-2alpha protein was expressed positively in 67.1% (47/70) of pancreatic cancer tissues and 11.4% (8/70) of adjacent non-tumor pancreatic tissues, and there was a significant difference in the positive rate of HIF-2alpha protein between two groups (chi2 = 45.549, P < 0.05). In addition, the staining for HIF-2alpha was correlated with tumor differentiation (P < 0.05), clinical stage (P < 0.05) and lymph node metastasis (P < 0.05), while E-cadherin expression was only correlated with lymph node metastasis (P < 0.05). HIF-2alpha promoted cell migration, invasion in vitro, and regulated the expression of E-cadherin and MMPs, which are critical to EMT. Our further ChIP assay suggested that only Twist2 could bind to the promoter of E-cadherin in -714 bp region site, but there is no positive binding capacity in -295 bp promoter region site of E-cadherin. Clinical tissues IHC staining showed that Twist2 and E-cadherin expression had an obviously negative correlation in pancreatic cancer. Nevertheless, it had no obvious correlation between Twist1 and E-cadherin. CONCLUSION: These findings indicated that HIF-2alpha promotes EMT in pancreatic cancer by regulating Twist2 binding to the promoter of E-cadherin, which meant that HIF-2alpha and this pathway may be effective therapeutic targets for pancreatic cancer.

UNLABELLED: Globally, most patients are at late-stage when they have been diagnosed with ovarian cancer. Investigating the potential mechanisms involved in tumor progression and prognosis is essential for improving treatment options, outcomes, and survival. OBJECTIVE: This study elucidated the clinico-pathological significance of TWIST2 and the relationship of TWIST2, E-cadherin, and Vimentin expression in the progression and prognosis of epithelial ovarian cancer (EOC). MATERIALS AND METHODS: Immunohistochemical staining was used to quantify the expression and relevance of TWIST2, E-cadherin, and Vimentin in 103 ovarian specimens, including 30 cases of benign ovarian tumors, 30 cases of borderline ovarian tumors, and 43 cases of EOC. RESULTS: The expression of TWIST2 in the cytoplasm may help to maintain characteristics of epithelial cancer cells with E-cadherin normal membranous expression, while nuclear TWIST2 induces tumor translation front with membranous expression of Vimentin, which eventually promotes cancer metastasis. Moreover, the upregulation of TWIST2 was also related to the aberrant expression of E-cadherin and the increased expression of Vimentin, which were reported as important indicators of epithelial-mesenchymal transition (EMT). DISCUSSION: The data suggested that co-expression of TWIST2/Vimentin was an independent prognostic indicator for both overall survival and disease-free survival by multivariate Cox proportional hazards model. TWIST2 regulates EMT by depriving the epithelial cell phenotype of E-cadherin and endowing the mesenchymal cell phenotype with Vimentin, which may be involved in the progression and prognosis of ovarian cancer, and TWIST2/Vimentin co-expression might be a novel indicator with prognostic potential in EOC patients.

In this study, we aimed to explore new downstream effectors of TWIST1/2 in inducing epithelial-to-mesenchymal transition in gastric cancer. Bioinformatic data mining was performed using data in The cancer Genome Atlas Stomach Adenocarcinoma. Survival curves were generated using Kaplan-Meier plotter. Gastric cancer cell lines (AGS and SGC-7901) were used as in vitro cell model to investigate the regulative effect of TWIST1/2 on epithelial membrane protein 3 expression and the progression of epithelial-to-mesenchymal transition. Results showed that TWIST1 and TWIST2 are usually co-upregulated in patients with primary gastric cancer. High TWIST1 expression is associated with worse overall survival (hazard ratio = 1.26; 95% confidence interval = 1.06-1.49; p = 0.007) and also worse first progression-free survival (hazard ratio = 1.47; 95% confidence interval = 1.18-1.82; p < 0.0001). Similarly, high TWIST2 expression is associated with unfavorable overall survival (hazard ratio = 1.71; 95% confidence interval = 1.32-2.22; p < 0.0001) and progression-free survival (hazard ratio = 1.99; 95% confidence interval = 1.45-2.72; p < 0.0001). epithelial membrane protein 3 is negatively correlated to CDH1 expression (Pearson's r = -0.46) but is positively correlated to VIM expression (Pearson's r = 0.83). Knockdown of epithelial membrane protein 3 significantly increased E-cadherin but significantly decreased Vimentin expression in AGS cells. Gastric cancer patients with metastasis have significantly higher epithelial membrane protein 3 expression than the cases without metastasis. In addition, high epithelial membrane protein 3 expression is associated with worse overall survival (hazard ratio = 2.59; 95% confidence interval = 2.06-3.26; p < 0.0001) and also worse progression-free survival (hazard ratio = 2.21; 95% confidence interval = 1.78-2.74; p < 0.0001). In conclusion, epithelial membrane protein 3 is a downstream effector of TWIST1/2 in inducing epithelial-to-mesenchymal transition in gastric cancer. epithelial membrane protein 3 upregulation might be associated with gastric cancer metastasis and is a potential indicator of unfavorable overall survival and progression-free survival in gastric cancer patients.

We have earlier found abnormal expression of the mitochondrial ribosomal protein S18-2 (MRPS18-2, S18-2) in endometrial cancer, compared to the expression in hyperplasia and in normal endometrium. Here we report that expression of S18-2 was increased with disease progression in clinical specimens of prostate cancer (PCa). The level of induction of epithelial to mesenchymal cell transition (EMT) correlated with the expression level of S18-2 in PCa cell lines. Moreover, cells acquired increased ability of migration upon S18-2 overexpression, as was evaluated in zebrafish embryo model and in trans-well assay. We found that this is due to increased CXCR4 cell surface expression. Neutralizing CXCR4 protein or abrogating S18-2 expression in cells significantly reduced their migratory ability directed toward CXCL12. The mRNA expression of TWIST2, encoding one of transcription factors that induce EMT upon CXCR4 increase, positively correlated with the S18-2 protein level. Together, these data suggest that the S18-2 protein induces EMT through the TWIST2/E-cadherin signalling and, consequently, CXCR4-mediated migration of PCa cells.