DNMT3A low-expression is correlated to poor prognosis in childhood B-ALL and confers resistance to daunorubicin on leukemic cells.

BACKGROUND: Little is known about DNMT3A expression and its prognostic significance in childhood B cell acute lymphoblastic leukemia (B-ALL).

METHODS: We determined DNMT3A mRNA expression in 102 children with B-ALL. Correlations with relapse-free survival (RFS) and common clinical characteristics were analyzed. DNMT3A was stably knocked out by CRISPR/Cas9 gene editing technology in Reh and 697 B-ALL cell lines. Cell proliferation activity after treated with daunorubicin (DNR) was determined by CCK8 assay in DNMT3A KO Reh and 697 cell lines.

RESULTS: DNMT3A expression in B-ALL patients who were in continuous complete remission (CCR) was higher than in those who got relapse (P = 0.0111). Receiver operating characteristic curve showed prognostic significance of DNMT3A expression (P = 0.003). Low expression of DNMT3A (≤ 0.197) was significantly correlated with poor RFS (P < 0.001) in children with B-ALL. Knock-out of DNMT3A in Reh and 697 cell lines significantly increased IC50 of DNR (P = 0.0201 and 0.0022 respectively), indicating elevated resistance to DNR.

CONCLUSION: Low expression of DNMT3A associates with poor prognosis in children with B-ALL. Knock-out of DNMT3A confers resistance to DNR on leukemic cells.