Study of DNA demethylation acting on DNA methyltransferase gene and microRNA in B-cell acute lymphocytic leukemia cell line

Abstract

Objective To explore the function of 5-Aza-CdR in B-cell acute lymphocytic leukemia cell line NALM-6 and its influence on the expression of microRNA (miRNA) in the cells. Methods NALM-6 was treated with different concentrations of 5-Aza-CdR. Cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) test, and DNA methyltransferase (DNMT) mRNA expression level was detected by reverse transcription PCR (RT-PCR). The expression changes of miRNA were detected by miScript miRNA PCR Array chip in cells after methylation. Results NALM-6 cell growth was inhibited by different concentrations of 5-Aza-CdR processing time, reaching to the maximum inhibitory rate was (74.163±0.381)%. 5-Aza-CdR affected concentrations was inversely proportional with expression level of DNMT mRNA. After 1 000 μmol/L of 5-Aza-CdR was dealed with cell 72 h, the relative expression of DNMT-1 was reduced to 0.453±0.021, DNMT-3L was 0.003±0.001, DNMT-3B was 0.395±0.019. MiScript miRNA PCR array sieved out 3 miRNA (miR-184, miR-23a-3p, miR-34a-5p) associated with DNA methylation. Conclusions 5-Aza-CdR down regulates the expression of DNMT gene in NALM-6 cells, and inhibits the proliferation of cells. MiR-184, miR-23a-3p and miR-34a-5p are related to DNA methylation in the occurrence and development of B-cell acute lymphocytic leukemia. Key words: Leukemia, B-cell lymphocytic, acute; DNA methylation; MicroRNA; 5-Aza-CdR