Development of Tumor-Induced Bystander Effect and Radiosensitivity in the Peripheral Blood Lymphocytes of Glioblastoma Patients with Different MGMT Gene Methylation Statuses in Tumor Cells

The effect of the MGMT gene methylation in glioblastoma cells on the development of the tumor-induced bystander effect and the modification of sensitivity, due to the impact of ionizing radiation, in the untransformed bystander cells (peripheral blood lymphocytes) was studied. The obtained results showed development of a glioblastoma-induced bystander effect. No association between the manifestation of the tumor-induced bystander effect and the methylation status of the MGMT gene promoter region in tumor cells has been found. After the exposure to radiation, statistically significant (p < 0.01) changes were observed in the apoptotic activity and radiosensitivity of peripheral blood lymphocytes with different statuses of the MGMT gene methylation in the tumor cells of glioblastoma patients.