9839

ZEB2

zinc finger E-box binding homeobox 2;ZEB2;zinc finger E-box binding homeobox 2

SMAD interacting protein 1|Smad-interacting protein 1|zinc finger E-box-binding homeobox 2|zinc finger homeobox 1b

2q22.3

protein-coding

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.

The epithelial-mesenchymal transition (EMT) contributes to cancer metastasis. Two ZEB family members, ZEB1 and ZEB2(SIP1), inhibit transcription of the E-cadherin gene and induce EMT in vitro. However, their relevance to human cancer is insufficiently studied. Here, we performed a comparative study of SIP1 and ZEB1 proteins in cancer cell lines and in one form of human malignancy, carcinoma of the bladder. Whereas ZEB1 protein was expressed in all E-cadherin-negative carcinoma cell lines, being in part responsible for the high motility of bladder cancer cells, SIP1 was hardly ever detectable in carcinoma cells in culture. However, SIP1 represented an independent factor of poor prognosis (P = 0.005) in a series of bladder cancer specimens obtained from patients treated with radiotherapy. In contrast, ZEB1 was rarely expressed in tumor tissues; and E-cadherin status did not correlate with the patients' survival. SIP1 protected cells from UV- and cisplatin-induced apoptosis in vitro but had no effect on the level of DNA damage. The anti-apoptotic effect of SIP1 was independent of either cell cycle arrest or loss of cell-cell adhesion and was associated with reduced phosphorylation of ATM/ATR targets in UV-treated cells. The prognostic value of SIP1 and its role in DNA damage response establish a link between genetic instability and metastasis and suggest a potential importance for this protein as a therapeutic target. In addition, we conclude that the nature of an EMT pathway rather than the deregulation of E-cadherin per se is critical for the progression of the disease and patients' survival.

The expression of Smad interacting protein-1 (SIP1; ZEB2) and the de novo expression of vimentin are frequently involved in epithelial-to-mesenchymal transitions (EMTs) under both normal and pathological conditions. In the present study, we investigated the potential role of SIP1 in the regulation of vimentin during the EMT associated with breast tumor cell migration and invasion. Examining several breast tumor cell lines displaying various degrees of invasiveness, we found SIP1 and vimentin expression only in invasive cell lines. Also, using a model of cell migration with human mammary MCF10A cells, we showed that SIP1 is induced specifically in vimentin-positive migratory cells. Furthermore, transfection of SIP1 cDNA in MCF10A cells increased their vimentin expression both at the mRNA and protein levels and enhanced their migratory abilities in Boyden Chamber assays. Inversely, inhibition of SIP1 expression by RNAi strategies in BT-549 cells and MCF10A cells decreased vimentin expression. We also showed that SIP1 transfection did not activate the TOP-FLASH reporter system, suggesting that the beta-catenin/TCF pathway is not implicated in the regulation of vimentin by SIP1. Our results therefore implicate SIP1 in the regulation of vimentin observed in the EMT associated with breast tumor cell migration, a pathway that may contribute to the metastatic progression of breast 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.

OBJECTIVES: Both epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties may be involved in metastasis, which contributes to the high mortality rate of patients with head and neck cancers (HNCs). However, the mechanisms through which the EMT transcription factors ZEB1 and ZEB2 regulate HNC are still unclear. METHODS: tumor initiating capability of HNC-CH133(+) cells with ZEB1/2 knockdown or co-overexpression was presented in vitro and in vivo. RESULTS: In the present study, we demonstrated that ZEB1/ZEB2 expression was significantly increased in HNC-CD133(+) CSC-like cells compared with HNC-CD133(-) cells. The small interfering RNA (siRNA)-mediated co-knockdown of ZEB1 and ZEB2 (siZEB1/2) in HNC-CH133(+) cells suppressed their CSC-like properties, including self-renewal ability, the expression of stemness markers, and drug resistance. In contrast, the co-overexpression of ZEB1/ZEB2 in HNC-CD133(-) cells enhanced their sphere-forming ability and increased the percentage of CD44-positive cells and side population cells. In vivo studies showed that the delivery of siZEB1/2 to xenograft tumors in nude mice reduced tumor growth and the rate of distant metastasis. In clinical samples, the levels of ZEB1/ZEB2 expression were low in local lesions but high in metastatic lymph nodes in HNC tissues. Patients with tumors that co-expressed ZEB1(high) and ZEB2(high) had especially poor survival rates. CONCLUSION: Therapies targeting ZEB1/ZEB2 in HNC-CD133(+) cells may provide a new approach for HNC therapy in the future.

Forkhead box Q1 (FoxQ1) is a master regulator of tumor metastasis. However, the molecular mechanism of FoxQ1 in regulating hepatocellular carcinoma (HCC) metastasis remains unknown. Here we report a novel function for FoxQ1 in modifying the tumor microenvironment to promote HCC metastasis. FoxQ1 expression was an independent and significant risk factor for the recurrence and survival in two independent cohorts totaling 1,002 HCC patients. FoxQ1 induced epithelial-mesenchymal transition (EMT) through the transactivation of ZEB2 expression by directly binding to the ZEB2 promoter. Knockdown of ZEB2 decreased FoxQ1-enhanced HCC metastasis, whereas up-regulation of ZEB2 rescued the decreased metastasis induced by FoxQ1 knocking down. Additionally, serial deletion, site-directed mutagenesis, and a chromatin immunoprecipitation assays showed that VersicanV1, which promoted HCC metastasis and macrophage attraction, was a direct transcriptional target of FoxQ1. FoxQ1-induced VersicanV1 expression promoted the secretion of chemokine (C-C motif) ligand 2 (CCL2) from HCC cells. Chemotaxis assay showed that the culture media from FoxQ1-overexpressing HCC cells increased the migratory activity of the macrophages. Inhibition of VersicanV1 and CCL2 expression significantly inhibited FoxQ1-mediated macrophage migration. In animal studies, the up-regulation of FoxQ1 in HCC cells promoted HCC metastasis and intratumoral tumor associated macrophage (TAM) infiltration, whereas knockdown of VersicanV1 reduced FoxQ1-mediated HCC metastasis and intratumoral TAM infiltration. Depletion of macrophages using clodronate liposomes dramatically decreased FoxQ1-enhanced HCC metastasis. In human HCC tissues, FoxQ1 expression was positively correlated with ZEB2 and VersicanV1 expression and intratumoral TAM infiltration. Patients with positive coexpression of FoxQ1 and ZEB2, FoxQ1, and VersicanV1, or FoxQ1 and intratumoral TAMs were associated with poorer prognosis. CONCLUSION: FoxQ1 promotes HCC metastasis by transactivating ZEB2 and VersicanV1 expression, resulting in the induction of EMT and the recruitment of macrophage infiltration.

Epithelial to mesenchymal transition (EMT) facilitates tissue remodelling during embryonic development and is viewed as an essential early step in tumour metastasis. We found that all five members of the microRNA-200 family (miR-200a, miR-200b, miR-200c, miR-141 and miR-429) and miR-205 were markedly downregulated in cells that had undergone EMT in response to transforming growth factor (TGF)-beta or to ectopic expression of the protein tyrosine phosphatase Pez. Enforced expression of the miR-200 family alone was sufficient to prevent TGF-beta-induced EMT. Together, these microRNAs cooperatively regulate expression of the E-cadherin transcriptional repressors ZEB1 (also known as deltaEF1) and SIP1 (also known as ZEB2), factors previously implicated in EMT and tumour metastasis. Inhibition of the microRNAs was sufficient to induce EMT in a process requiring upregulation of ZEB1 and/or SIP1. Conversely, ectopic expression of these microRNAs in mesenchymal cells initiated mesenchymal to epithelial transition (MET). Consistent with their role in regulating EMT, expression of these microRNAs was found to be lost in invasive breast cancer cell lines with mesenchymal phenotype. expression of the miR-200 family was also lost in regions of metaplastic breast cancer specimens lacking E-cadherin. These data suggest that downregulation of the microRNAs may be an important step in tumour progression.

BACKGROUND AND OBJECTIES: Phenotypic plasticity of cancer cells via epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) is essential for tumor progression and metastasis. METHODS: Tissue samples were obtained from 76 pancreatic head cancers. We assessed the expression of E-cadherin, vimentin, ZEB-1, and ZEB-2 by immunohistochemical and immunofluorescence staining. Next, 147 metastatic lymph nodes from 45 pancreatic cancers with low expression of E-cadherin were obtained and divided into two categories according to the maximum diameter of the metastases: 2 mm or more and less than 2 mm. RESULTS: High expressions of ZEB-1 and ZEB-2 in the primary tumors were significantly associated with repression of E-cadherin (P = 0.0007), and poorer prognosis (P = 0.0322). Forty-three (29.3%) of the 147 metastatic tumors from pancreatic cancers with low expression of E-cadherin showed high E-cadherin expression. cancer cells in the larger metastases showed high expression of E-cadherin (P = 0.0061) and low expression of ZEB-1 (P = 0.0170) and ZEB-2 (P = 0.0036) compared with those in the smaller metastases. CONCLUSIONS: In primary pancreatic tumors and metastatic lymph nodes, high and low expression of ZEB-1 and ZEB-2 was associated with mesenchymal and epithelial phenotype of cancer cells, respectively.

MicroRNAs (miRNAs) represent a class of small, non-coding RNAs that control gene expression by targeting mRNA and triggering either translational repression or RNA degradation. The objective of our study was to evaluate the involvement of miRNAs in human medullary thyroid carcinoma (MTC) and to identify the markers of metastatic cells and aggressive tumour behaviour. Using matched primary and metastatic tumour samples, we identified a subset of miRNAs aberrantly regulated in metastatic MTC. Deregulated miRNAs were confirmed by quantitative real-time PCR and validated by in situ hybridisation on a large independent set of primary and metastatic MTC samples. Our results uncovered ten miRNAs that were significantly expressed and deregulated in metastatic tumours: miR-10a, miR-200b/-200c, miR-7 and miR-29c were down-regulated and miR-130a, miR-138, miR-193a-3p, miR-373 and miR-498 were up-regulated. Bioinformatic approaches revealed potential miRNA targets and signals involved in metastatic MTC pathways. Migration, proliferation and invasion assays were performed in cell lines treated with miR-200 antagomirs to ascertain a direct role for this miRNA in MTC tumourigenesis. We show that the members of miR-200 family regulate the expression of E-cadherin by directly targeting ZEB1 and ZEB2 mRNA and through the enhanced expression of tumour growth factor beta (TGFbeta)-2 and TGFbeta-1. Overall, the treated cells shifted to a mesenchymal phenotype, thereby acquiring an aggressive phenotype with increased motility and invasion. Our data identify a robust miRNA signature associated with metastatic MTC and distinct biological processes, e.g., TGFbeta signalling pathway, providing new potential insights into the mechanisms of MTC metastasis.