Relationship between CYP17A1-Mediated DNA Demethylation and Proliferation, Invasion and Metastasis of Glioma Cells.

Objective: We investigated the relationship between CYP17A1-mediated DNA demethylation and proliferation, invasion, and metastasis of glioma cells.
Methods: The expression of CYP17A1 mRNA and protein in cells was determined by PCR and Western blot assays. The methylation status of CYP17A1 was detected by the MSP method. Cell proliferation and apoptosis were detected by MTT assays and flow cytometry. Cell invasion and metastasis were measured by cell invasion assays.
Results: The relative expression of CYP17A1 mRNA was significantly different among the model, experimental, and normal groups (P < 0.05). Relative expression was significantly decreased in the experimental group relative to the cancer model group (P < 0.05). Immunohistochemistry showed that expression of CYP17A1 in glioma was significantly higher than in the normal group (P < 0.05). Methylation analysis showed that CYP17A1 was not detected in normal cells, and the methylation rate in the model group was 89.03%. The methylation rate in the experimental group was 43.93%, which was significantly lower than that of the model group (P < 0.05). MTT assays showed that DHEA plus temozolomide (TMZ) pretreatment significantly inhibited cell proliferation rate (P < 0.05). Flow cytometry showed that DHEA plus TMZ pretreatment significantly increased apoptosis rate (P < 0.05). In colony formation assays, the number of CYP17A1 colonies in the model and experimental groups was 78.09% ± 10.21% and 38.97% ± 11.32%, respectively. The number of colonies in the experimental group was significantly lower than in the model group (P < 0.05). The migration ability of the model group was significantly higher than that of the control group (P < 0.05). The invasion rate of the experimental group was significantly lower than that of the model group (P < 0.05).
Conclusion: CYP17A1-induced DNA demethylation can inhibit proliferation, invasion, and metastasis of glioma cells.