The prognostic value of IDH1 mutations has been systematically evaluated in acute myeloid leukemia (AML) patients recently. However, the role of IDH1 expression in AML is still under exploration. To investigate the clinical significance, we analyzed the IDH1/2 expression in 320 patients with cytogenetically normal AML (CN-AML) by quantitative real-time reverse-transcription polymerase chain reaction. High expression of IDH1 was predominant in patients with FLT3-ITD and DNMT3A mutations and less prevalent in cases with CEBPA double allele mutations. Strong association was observed between high IDH1 expression and low expression of microRNA 181 family. Prognosis was adversely affected by high IDH1 expression, with shorter overall survival and event-free survival in the context of clinical characteristics, including age, WBC count, and gene mutations of NPM1, FLT3-ITD, CEBPA, IDH1, IDH2 and DNMT3A in CN-AML. Moreover, the clinical outcome of IDH1 expression in terms of overall survival, event-free survival and complete remission rate still remained in multivariate models in CN-AML. Importantly, the prognostic value was validated using the published microarray data from 79 adult patients treated according to the German AMLCG-1999 protocol. Our results demonstrated that high IDH1 expression is associated with a poor prognosis of CN-AML.

The risk factors and the role of prophylactic antiviral therapy of hepatitis B virus (HBV) reactivation in patients with hepatitis B surface antigen (HBsAg) negative/hepatitis B core antibody (HBcAb) positive disease remain controversial. We reviewed 629 patients with diffuse large B-cell lymphoma (DLBCL). Among 629 patients, 150 of 246 patients with resolved HBV (HBsAg negative and HBcAb positive) were treated with rituximab-combined therapy. Among these 150 patients, none of 104 patients (0.0%) who were hepatitis B surface antibody (HBsAb) positive experienced HBV reactivation versus four of 46 patients (8.7%) who were HBsAb negative (p = 0.008). One of 113 patients (0.9%) with International Prognostic Index (IPI) 0-2 suffered HBV reactivation versus three of the remaining 37 patients (8.1%) with IPI 3-5 (p = 0.047). HBsAb and IPI are potential risk factors for HBV reactivation. The use of prophylactic agents may not be recommended for these patients until the occurrence of HBV reactivation.

The prognostic value of IDH1 mutations has been systematically evaluated in acute myeloid leukemia (AML) patients recently. However, the role of IDH1 expression in AML is still under exploration. To investigate the clinical significance, we analyzed the IDH1 expression in 320 patients with cytogenetically normal AML (CN-AML) by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). High expression of IDH1 was predominant in patients with FLT3-ITD and DNMT3A mutations, and less prevalent in cases with CEBPA double allele mutations. Strong association was observed between high IDH1 expression and low expression of micro-RNA 181 family. Prognosis was adversely affected by high IDH1 expression with shorter overall survival (OS) and event free survival (EFS) in the context of clinical characteristics including age, WBC, and gene mutations of NPM1, FLT3-ITD, CEBPA, IDH1, IDH2, and DNMT3A in CN-AML. Moreover, the clinical outcome of IDH1 expression in terms of OS, EFS and complete remission rate still remained in multivariate models in CN-AML. Importantly, the prognostic value was validated using the published microarray data from 79 adult patients treated according to the German AMLCG-1999 protocol. Our results demonstrated that high IDH1expression is associated with a poor prognosis of CN-AML. Disclosures No relevant conflicts of interest to declare.

BACKGROUND AND PURPOSEHomoharringtonine (HHT) is a natural alkaloid isolated from various Cephalotaxus species. HHT has been used to treat acute myeloid leukaemia (AML), chronic myeloid leukaemia (CML), chronic lymphocyte leukaemia and myelodysplastic syndromes. Although HHT inhibits protein synthesis and promotes apoptosis of leukaemia cells in preclinical studies, its molecular target proteins remain unknown. The aim of this study was to identify target proteins of HHT. EXPERIMENTAL APPROACHWe have synthesized a biotinylated affinity column and used it to identify targets of HHT and confirmed the results by MS and Western blots. We also examined the effects of HHT on the target protein and determined roles of the target protein in antileukaemia activities of HHT through Western blots, flow cytometry and retrovirus transfection. KEY RESULTSMyosin-9, a member of the myosin super-family, was identified as a direct interactor of HHT. Furthermore, HHT up-regulated the expression level of myosin-9 in both AML and CML cell lines in a time-dependent manner. Thus, HHT-induced apoptosis of leukaemia cells begins in 6 h and continues to increase for 24 h. There is a positive correlation between up-regulated myosin-9 expression level and increased percentage of apoptotic cells mediated by HHT. Overexpression of myosin-9 could increase the sensitivity of the leukaemia cells to the cytotoxicity of HHT and arrest cells in S and G2/M phases. CONCLUSIONS AND IMPLICATIONSOur results indicated that myosin-9 was the target protein of HHT and played an important role in the HHT-induced apoptosis of leukaemia cells. AbbreviationsAML, acute myeloid leukaemia; CML, chronic myeloid leukaemia; GST, glutathione S-transferase; HHT, homoharringtonine; NM II, non-muscle myosin II; NMHC-IIA, non-muscle myosin heavy chain-IIA; alternatively called myosin-9; TKI, TK inhibitor BJP British Journal of Pharmacology