Inhibition of the proliferation, invasion, migration, and epithelial-mesenchymal transition of prostate cancer cells through the action of ATP1A2 on the TGF-β/Smad pathway

摘要

Background: Prostate cancer (PC) is one of the major male malignancies worldwide. Because Na+-K+-ATPase is widely involved in various pathological processes, but the action of its alpha 2 subtype (ATP1A2) in PC is unclear, we investigated the role of ATP1A2 in the invasion and migration of PC cells. @@@ Methods: We measured the expression levels of ATP1A2 in human normal prostate epithelial cell line (RWPE-1) and PC cell lines (PC-3 and DU145) by quantitative real-time PCR (qRT-PCR) and western blot. Cell proliferation, apoptosis, migration, and invasion of PC-3 and DU145 cells were investigated through clone formation assay, EdU assay, flow cytometry and transwell assay, respectively. The effect of ATP1A2 on a tumor-inhibitory pathway [transforming growth factor-beta (TGF-beta)/Smad] was assessed using western blot. In addition, tumor formation was detected using in vivo xenograft model in male BALB/c nude mice. @@@ Results: The Cancer Genome Atlas (TCGA) analysis showed that ATP1A2 expression was reduced in PC patients (P<0.05), and patients with low ATP1A2 expression had a lower survival rate (P<0.05). ATP1A2 levels were significantly reduced in PC-3 and DU145 cells, compared with RWPE-1 cells (P<0.01). We also demonstrated that overexpression of ATP1A2 significantly inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of PC-3 and DU145 cells (P<0.01) and promoted apoptosis (P<0.01). However, silencing ATP1A2 had the opposite effect (P<0.01). In addition, overexpression of ATP1A2 significantly inhibited the TGF-beta/Smad pathway (P<0.01), whereas silencing ATP1A2 activated the TGF-beta/Smad pathway (P<0.01). Meanwhile, the effect of ATP1A2 silencing on the proliferation, apoptosis, migration and invasion was reversed by TGF-beta/Smad pathway inhibitor (LY364947). Furthermore, ATP1A2 inhibited tumor growth in vivo. @@@ Conclusions: ATP1A2 inhibited proliferation, apoptosis, migration, invasion, and EMT in PC by inhibiting the TGF-beta/Smad pathway.

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