HIF-1α restricts proliferation and apoptosis of Tca8113 cells through up regulation of Hippo signaling pathway under hypoxic conditions.

Abstract

The hypoxia-inducible factor-1α (HIF-1α) is a key factor for tumor cells adaptation to hypoxia. Studies have shown that under hypoxic conditions, HIF-1α expression was significantly increased in human tongue squamous cell carcinoma cells (Tca8113). This research aims to determine the exact mechanism of HIF-1α on the proliferation and apoptosis of Tca8113 cells. Tca8113 cells were cultured under normoxia and hypoxia. Real Time-PCR and Western blot were used to measure the expression levels of HIF-1α and TAZ. Under hypoxic condition, HIF-1α siRNA was transfected into Tca8113 cells. CCK8 was used to measure the proliferation of Tca8113 cells. Flow cytometry was used to detect apoptosis of Tca8113 cells. Under hypoxic condition, the expression levels of HIF-1α and TAZ at both mRNA and protein levels were significantly increased (p <0.05). The downregulation of HIF-1α by siRNA significantly inhibited Tca8113 cells proliferation, increased their apoptosis, and reduced the expression level of TAZ. Under hypoxic conditions, HIF-1α inhibits the proliferation and apoptosis of Tca8113 cells via the elevation of the Hippo signaling pathway.