Effect of down-regulation of MLAA-22 gene on proliferation and differentiation of U937 cells / 西安交通大学学报(医学版)

ABSTRACT

Objective To explore the effect of down-regulation of MLAA-22 gene on proliferation and differentiation of U937 cells.Methods MLAA-22 gene was down-regulated by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9)system in U937 cells.The activity of single guide RNA (sgRNA)was detected by CruiserTMenzyme digestion assay.The mutation rate of MLAA-22 gene was analyzed by TA cloning and sequencing assay of PCR products of the gene mutation region.Cell proliferation was evaluated by CCK-8 assay.Expression of CD11b was tested by flow cytometry to evaluate cell differentiation. Results CruiserTMenzyme digestion assay showed the sgRNA of the CRISPR/Cas9 system identified the target spot efficiently.TA cloning and sequencing assay displayed the mutation rate of MLAA-22 gene was 61.3%.CCK-8 assay demonstrated that the proliferation was obviously inhibited in MLAA-22-knockdown U937 cells.In addition, flow cytometry assay indicated CD11b-positive cells significantly increased in MLAA-22-knockdown U937 cells. Conclusion MLAA-22 gene regulates the proliferation of U937 cells probably by regulating their differentiation, thus promoting the occurrence and development of acute monocytic leukemia.