Hypoxia promotes the proliferation of cervical carcinoma cells through stimulating the secretion of IL-8

To explore whether hypoxia and interleukin 8 (IL-8) regulate the viability and apoptosis of cervical carcinomas cells and the possible mechanism. We evaluated the expression of hypoxia inducible factor-1α (HIF-1α), IL-8 and its receptors (CXCR1 and CXCR2) in cervical cancer and cervicitis tissues by immunohistochemistry. Then the effects of hypoxia and IL-8 on the viability and apoptosis of HeLa and SiHa cells were detected by the SRB and apoptosis assays. Here we observed that the expression of HIF-1α, IL-8 and CXCR1 in cervical cancer tissues was significantly higher than that in cervicitis tissues. Hypoxic condition stimulated the secretion of IL-8 and the expression of CXCR1 and CXCR2 on HeLa and SiHa cells. Recombinant human IL-8 enhanced the viability and reduced the apoptosis in HeLa and SiHa cells. HeLa and SiHa cells cultured in 1% oxygen showed the increased viability and apoptosis, and the former effect could be partly reversed by anti-human IL-8 neutralizing antibody. This data suggested that IL-8 secreted by cervical carcinomas cells induced by hypoxia can stimulate the viability of cervical carcinomas cells in an autocrine dependent manner, and contribute to the pathogenesis of cervical cancer.