Effect of 5- azacytidine (5-aza-CR on the expression of DNMT1, DNMT3A, DNMT3B, p14ARF, p16INK4a, and p15INK4b, cell growth inhibition and apoptosis induction lung cancer A549 cell line

Background and aim: Lung cancer is one of the most leading causes of cancer death in males and females and the second leading cause of cancer death. Epigenetic alterations, including DNA hypermethylation, histone deacetylation, and miRNAs lead to the silencing of tumor suppressor genes (TSGs) resulting in tumorigenesis. This change has been reported in various cancers. The activity of DNA methyltransferase (DNMT) enzymes leads to hypermethylation of TSGs resulting in silenced genes and tumorigenesis. Hence, the use of specific inhibitors of DNMTs such as 5- azacytidine (5-aza-CR) can reactivate TSGs. Previously, we reported the effect of 5-AZA-CdR on hepatocellular carcinoma (HCC) and colon cancer [9-11]. The present study was designed to investigate the effect of 5-AZA-CdR on DNMT1, DNMT3A, DNMT3B, p14ARF, p16INK4a, and p15INK4b gene expression, cell growth inhibition, and apoptosis induction in lung cancer A549 cell line. Materials and Methods: The A549 cells were treated with 5-AZA-CdR. To determine cell viability, cell apoptosis and gene expression, MTT assay, flow cytometry and Real-time quantitative RT-PCR (qRT-PCR) were done respectively.  Results: 5-aza-CR inhibited cell viability, induced apoptosis, decreased DNMT1, DNMT3a, and DNMT3b and increased p14ARF, p16INK4a, and p15INK4b significantly. Conclusion: 5-AZA-CdR can down-regulate DNMT1, DNMT3a, and DNMT3b, and up-regulate p14ARF, p16INK4a, and p15INK4b and induce apoptosis in lung cancer cell A549 line.