Methylation Patterns of the IFN-γ Gene in Cervical Cancer Tissues

OBJECTIVE To explore the relationship between methylation of interferon gamma (IFN-γ) gene and tumorigenesis in cervical cancer tissues, the biopsy specimens of cervical cancer and cervical intraepithelial neoplasia (CIN) (I-III) patients as well as normal controls were collected and analyzed. METHODS The methylation of the IFN-γ gene was verified by using methylation-specific PCR and DNA sequencing analysis, and the expression levels of IFN-γ mRNA were detected using quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). RESULTS The methylation rates of the IFN-γ gene were significantly higher in cervical cancer tissues (15/43, 34.9%) than those in CIN (3/23, 13.0% of CIN I; 6/39, 15.4% of CIN II/III) and normal cervical tissues (2/43, 4.7%) (P < 0.01). Furthermore, the mRNA expression of IFN-γ in cervical tumors with methylation (0.71 ± 0.13, n = 8) was lower than that in those without methylation (1.58 ± 0.32, n = 27) (P < 0.05). Likewise, the IFN-γ expression levels in CIN II/III tissues with methylation (0.87 ± 0.16, n = 5) were significantly (P < 0.01) lower compared to those without methylation (2.12 ± 0.27, n = 32). CONCLUSION The hypermethylation of IFN-γ gene may be related with tumorigenesis of cervical cancer.