Aberrant activated APOBEC3B is associated with p53 mutant-driven refractory/relapsed Diffuse Large B-cell Lymphoma

Abstract BackgroundAlthough treatment of diffuse large B-cell lymphoma (DLBCL) has progressed considerably in recent years, treatment failure still occurs in about 40% of patients who are refractory/relapse. Recent studies suggest that TP53 mutation may be an important cause of refractory/relapse in DLBCL, but the cause of TP53 mutation remains unclear. MethodsIn the present study, the correlation between TP53 mutation status and APOBEC3A and APOBEC3B expression in DLBCL specimens was searched by detecting the correlation between TP53 mutation and APOBEC3B expression in combination with database informatics analysis. Further, the relationship between APOBEC3B expression and TP53 mutation was analyzed by constructing APOBEC3B induced expression DLBCL cell lines. The effects of APOBEC3B-induced TP53 mutants on DLBCL cell proliferation and drug resistance were also tested. ResultsWe identify APOBEC3B as a critical factor that regulates p53-mutant driven drug resistance of DLBCL. APOBEC3B induces TP53 mutations of DLBCL cells, and its mutation patterns are similar to those in DLBCL patients. Moreover, APOBEC3B-induced p53 mutants promoted growth of DLBCL cells as well as contributed to drug resistance. In human DLBCL, APOBEC3B is aberrantly activated and associated with p53 mutant-mediated refractory/relapsed DLBCL. ConclusionThese findings yield insights into the mechanism of refractory/relapsed DLBCL induced by p53 mutants and reveal APOBEC3B as a new therapeutic target.