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

Hypoxia-inducible-1α (HIF-1α) expression was intimately correlated withapoptosis and proliferation of cancer cells. However, conclusions of differentstudies on the effects of HIF-1α expression on cell apoptosis and cell proliferationof hepatoma cells remain controversial. In view of the current status, we reassessits roles and possible mechanism in hepatoma cells. In order to acquire more convincingand reliable results, we used a Tet-on system to stably and effectively regulateHIF-1α expression in the HepG2 cells in vitro. In our study we not only confirmedsome common conclusions of previous studies, but also acquired some differentand significant results that HIF-1α facilitates cell proliferation and cell cyclethrough influencing the expression of cyclin A and cyclin D, and suppresses cellapoptosis through inducing the expression of survivin and Bcl-2. These resultsfurther enrich our knowledge on the role of HIF-1α expression on cell apoptosisand cell proliferation of hepatoma cells.