Objective: To investigate the role of transmembrane prostate androgen-induced protein 1 (PMEPA1), an important gene downstream of transforming growth factor-β (TGF-β) signaling, in the process of breast cancer cell migration and epithelial-mesenchymal transition.
Methods: We treated MDA-MB-231 breast cancer cells with TGF-β and TGF-β inhibitor SB431542, and then detect the level of PMEPA1 using Western blotting. PMEPA1-specific siRNA was designed and its knockdown efficiency was tested by quantitative real-time PCR (qRT-PCR). After the expression of PMEPA1 in MDA-MB-231 cells was successfully silenced, the wound-healing assay and Transwell(TM) assay were used to investigate the effect of PMEPA1 silencing on the migration of MDA-MB-231 cells. Moreover, phalloidin was used to label the actin cytoskeleton of breast cancer cells to observe the effect of PMEPA1 silencing on cell morphology.
Results: In breast cancer cells, PMEPA1 was upregulated by classical TGF-β/Smad signaling pathway. Silencing of PMEPA1 significantly inhibited the migration ability of MDA-MB-231 cells and promoted the process of mesenchymal-epithelial transition.
Conclusion: Over-expressed PMEPA1 can promote cell migration and maintain the mesenchymal-like morphology of breast cancer cells.