The compari̇son of the telomerase acti̇vi̇ty on melatoni̇n and 13-ci̇s-reti̇noi̇c aci̇d treated ykg-1 gli̇oblastoma multi̇forme cell li̇ne

Glioblastoma Multiforme (GBM) is the most common and most malignant astrocytic brain tumor seen in adults. They constitute 12-15% of intracranial tumors and 50-60% of astrocytic tumors. The incidence is higher in males than in females. Although the mortality rate of GBM is very high, there is no effective treatment method yet. On the other hand, 85% of malignancies (eg hematological malignancies) were found to have high telomerase activity. Therefore, telomerase activity is thought to be an important indicator in cancer diagnosis. High levels of telomerase activity are detected in 90% of tumors. The ability of cancer cells to have infinite cleavage ability and resistance is due to this recovered telomerase activity. We compared the effects of isotretinoin (13-cis retinoic acid), a vitamin A analogue, and an endogenous hormone, melatonin (MLT) on telomerase activity in YKG-1 glioblastoma cell line cells, a highly lethal tumor. Melatonin and 13-cis retinoic acid were separately and combined to calculate viability in these combinations using MTT. While MTT results were obtained, immunocytochemical staining and apoptotic staining of the same samples were performed to determine the caspase-3 and beclin-1 expressions in the samples. Then, immunopositive and immunonegative cells were counted in the light microscope and the results were statistically analyzed. As a result; We concluded that the effects of 13-cis retinoic acid on cell viability in the YKG-1 GBM cell line were not due to its effects on telomerase activity and other pathways or mechanisms were effective in this process and cell death was caused by autophagic cell death caused by beclin-1 expression.