Differential gene expression in cervical cancer cell lines before and after ionizing radiation

Our previous study demonstrated a correlation between increased apoptotic index in pre-radiotherapy cervical cancer and poor patient survival. Apoptosis may thus play an important role in the response of cervical cancer to radiation. Most of cervical carcinomas are associated with human papillomavirus (HPV), and the oncoproteins E6 and E7 disrupt the functions of tumour suppressor genes, resulting in genetic alteration. To understand the multiple genetic changes related to cell radiosensitivity and the induction of apoptosis, two cervical cancer cell lines, SiHa (with HPV infection) and C-33A (contains a mutant p53 gene), were selected for present studied. The gene expression patterns in these cell lines were compared before and after radiation. When compared to normal cervical tissues, differential expressions were observed in 46 genes among the two cell lines studied. Thirty-three genes showed altered expressions after radiation induction. Three out of ten genes that showed differential responsiveness to radiation in the two cell lines were further confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR). Bak and c-abl were found to be potential genes that may play important roles in signaling apoptosis in cervical cancer cells following radiation induction.