Telomerase and DNA repair in glioma

Both DNA repair (MGMT) and immortalisation (telomerase) have been linked to the root of cancer. In glioma, MGMT expression is negatively regulated through promoter methylation and its absence is associated with enhanced chemosensitivity. However, recent studies indicate that telomerase is positively regulated through methylation and its elimination enhances chemotherapy. These observations suggest that suppression of telomerase in combination with MGMT may have additional anti-proliferative and anti-apoptotic effects, which may lead to increased patient survival rates. However, different approaches may be required to compliment the epigenetic events that regulate these genes. Nevertheless, given that median survival of glioma patients is less than a year, this review focuses on the recent approaches used to target MGMT and telomerase, with a view to increase life expectancy of patients while limiting side effects.