Role of hypoxia-inducible-1α in hepatocellular carcinoma cells using a Tet-on inducible system to regulate its expression in vitro

Hypoxia-inducible-1 alpha (HIF-1 alpha) expression was intimately correlated with apoptosis and proliferation of cancer cells. However, conclusions of different studies on the effects of HIF-1 alpha expression on cell apoptosis and cell proliferation of hepatoma cells remain controversial. In view of the current status, we reassess its roles and possible mechanism in hepatoma cells. In order to acquire more convincing and reliable results, we used a Tet-on system to stably and effectively regulate HIF-1 alpha expression in the HepG2 cells in vitro. In our study we not only confirmed some common conclusions of previous studies, but also acquired some different and significant results that HI F-la facilitates cell proliferation and cell cycle through influencing the expression of cyclin A and cyclin D, and suppresses cell apoptosis through inducing the expression of survivin and Bcl-2. These results further enrich our knowledge on the role of HIF-1 alpha expression on cell apoptosis and cell proliferation of hepatoma cells.