Overexpression of transcriptional co-activator with PDZ-binding motif promotes epithelial mesenchymal transformation of ovarian cancer cells by upregulating Smad3 and Snail1

Abstract

This study is intended to explore the effect of transcriptional coactivator with PDZ binding motif (TAZ) expression in ovarian cancer cells as well as investigate the expression of signal proteins Smad3 and Snail1. Ovarian cancer cells (SKOV-3) were divided into two groups: control and TAZ overexpression. The overexpression of TAZ in SKOV-3 cells was determined by immunofluorescence, western blot, and qRT-PCR. The proliferation, invasiveness, and expression of epithelial mesenchymal transformation (EMT)-associated proteins were detected, and the expression of Smad3 and Snail1 proteins was determined by qRT-PCR and western blot, respectively. Small interfering RNA (siRNA) targeting TAZ were synthesized and used to transfect SKOV-3. Cell migration and invasion were observed via a wound healing assay and a transwell assay, respectively. The expressions of representative genes involved in proliferation and migration, EMT-associated proteins and Smad3 and Snail1 proteins were also detected by western blot assays. The results of qRT-PCR, immunofluorescence, and western blot showed that, compared with the control group, the expressions of Smad3 and Snail1 protein were upregulated, and the expression of EMT-related genes-including Actin, N-cadherin, and Vimentin protein-was downregulated in the TAZ overexpression group. After TAZ mRNA was suppressed, the migration and invasion ability of the TAZ siRNA group was weaker than that of the control group. In addition, the expression level of Smad3 and Snail1 decreased when TAZ was silenced, while the expression of EMT-related genes increased. Therefore, TAZ in ovarian cancer cells can promote growth, migration, and invasiveness of cancer cells by regulating genes related to proliferation, migration, and invasion.