MiR-133b regulates the expression of CTGF in epithelial-mesenchymal transition of ovarian cancer

L. Yang, J. Hou, X.-H. Cui, L.-N. Suo, Y.-W. Lv

Department of Obstetrics and Gynecology, First Affiliated Hospital of Chinese PLA General Hospital, Haidian District, Beijing, China. yanglee2000@126.com

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• Oncology

OBJECTIVE: To explore the role of miR-133b in ovarian cancer and to preliminarily elucidate the mechanism of miR-133b in epithelial-mesenchymal transition (EMT) of ovarian cancer.

PATIENTS AND METHODS: MiR-133b was detected in ovarian cancer specimens, and the relationship of miR-133b with each pathological index and clinical index of ovarian cancer was analyzed. The action targets of miR-133b in ovarian cancer were analyzed systematically and studied deeply via the target validation and cell function validation. Finally, the possible reasons of ovarian cancer metastasis were analyzed through the molecular regulation mechanism in EMT of ovarian cancer.

RESULTS: The miR-133b level in ovarian cancer was significantly lower than in normal ovarian tissues and benign ovarian tumors (p<0.05). The level of miR-133b in ovarian cancer was related to differentiated degree and lymphatic metastasis. Dual-luciferase assay indicated that connective tissue growth factor (CTGF) was the target gene regulated by miR-133b. Reverse transcriptase-polymerase chain reaction (RT-PCR) as well as Western blot results proved that the expression level of E-cadherin representing the epithelial cell phenotype was increased, while the expression level of vimentin representing the mesenchymal cell phenotype was decreased. Transwell assay confirmed that the migration and invasion abilities of ovarian cancer cells declined after transfection with miR-133b plasmid. After co-transfection with miR-133b and CTGF overexpression plasmids, RT-PCR and Western blotting proved that the expression level of E-cadherin representing the epithelial cell phenotype was decreased, while the expression level of vimentin representing the mesenchymal cell phenotype was increased; transwell assay confirmed that the cell migration and invasion abilities were increased after co-transfection.

CONCLUSIONS: The results of this study showed that miR-133b may serve as a new molecular marker of EMT of ovarian cancer, and act as a molecular marker of differentiated degree and lymphatic metastasis of ovarian cancer.

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