Abstract
Aberrant expression of P68 RNA helicase (p68), a prototypical member of the DEAD box family of RNA helicases, contributes to tumor development and progression. P68 tyrosine phosphorylation induced by PDGF signaling facilitates cancer metastasis by promoting EMT. In this report, we show that p68 promotes breast cancer cell EMT and cell migration by upregulation of PDGF receptor β (PDGFR-β). Knockdown of p68 in MDA-MB-231 and BT549 cells significantly decreases PDGFR-β both in mRNA and protein levels. P68 promotes EMT and cell migration in response to PDGF-BB stimulation via upregulation of PDGFR-β, suggesting that p68 enhances PDGF signaling by a positive feedback loop in cancer cells. Furthermore, our study reveals that p68 mediates the effects of PDGFR-β in regulation of androgen receptor (AR) in breast cancer cells. We demonstrate that p68 and PDGFR-β co-regulate AR expression and promote androgen-mediated proliferation in breast cancer cells. Our studies uncover an important pathway of p68-PDGFR-β axis in promoting breast cancer progression.