Identification of genes responsive to hypoxia in human cervical epithelial adenocarcinoma HeLa cells

It has been well-known that cancer cells acquire approximately three-fold radioresistance under hypoxia than under normoxia due to both radiation chemical and radiation biological mechanisms, causing a negative impact on the outcome of radiation therapy. In the present study, to identify genes responsive to hypoxia in human cervical epithelial adenocarcinoma HeLa cells, global-scale gene expression analysis was carried out using a GeneChip® system. Human cervical carcinoma cell line HeLa cells were used. Cells were cultured at 37°C in Dulbecco’s modified Eagle medium (DMEM) containing 10% FBS, 100 U/mL penicillin, and 100 μg/mL streptomycin. Cells were incubated in a well-humidified 5% CO2 and 95% air for the normoxic culture, or in a RUSKINN INVIVO2 500 for hypoxic culture at < 0.1% O2. Total RNA samples were prepared from the cells. Gene expression was analyzed by an Affymetrix GeneChip® system with a Human Genome U133-plus 2.0 array. Sample preparation for array hybridization was carried out as described in the manufacturer’s instructions.