Yüksek Doz Metilprednizolon’un HL-60 AML Hücrelerinde DNA Metilasyonu Üzerine Etkisi

Acute Myeloblastic Leukemia (AML) is a disease characterized with disruption of normal hematopoietic growth and differentiation and accumulation of numerous abnormal unmatured myeloid cells. Epigenetic mechanisms, in particular DNA methylation and histon modifications, play a major role in the modulation of gene activity in cancer and cause acute leukemias. Epigenetic changes can reverse pharmacologically with demethylating agents which are in use as targeted therapy of hematological malignancies. Methylprednisolone(MP) has been used with short course and high dose for treating newly diagnosed children with AML. Methylprednisolone induces differentiation of myeloid leukemia cells to granulocytes and macrophages and induces apoptosis of myleoid leukemia cells. First, MTT test is performed for evaluating how different MP doses effect cell cytotoxicity in time dependent manner. Viability decreased with increasing MP doses both 24. And 48. hours. For these doses, apoptosis and differentiation determinations were done with flow cytometry analysis. Following this step, the high and effective dose for HL- 60 cells established as 5x10-3. For this dose, DNA isolation wass done. After isolation, methylation specific PCR analysis was performed for p15, ER, CDX2 and Bcl-2 genes. According to results, while p15 and Bcl-2 gene promoters are unmethylated, ER and CDX2 gene promoters are methylated. In conclusion, the methylation profiles of p15, CDX2, ER and Bcl-2 do not change after MP treatment. MP has apoptotic effect and differentiates myeloid blast cells but it does not effect DNA methylation. It is the first in the literature that demonstrates if methylprednisolone shows its effect with epigenetic pathway. In conclusion HL-60 cell line shows that MP doesn’t effect DNA methylation.