Induction of apoptosis by HBI-8000 in adult T-cell leukemia/lymphoma is associated with activation of Bim and NLRP3

Adult T-cell leukemia/lymphoma (ATL) is an aggressive T-cell malignancy caused by human T-cell lymphotropic virus 1. Treatment options for acute ATL patients include chemotherapy, stem cell transplantation, and recently the anti-chemokine (C-C motif) receptor 4 antibody, although most patients still have a poor prognosis and there is a clear need for additional options. HBI-8000 is a novel oral histone deacetylase inhibitor with proven efficacy for treatment of T-cell lymphomas that recently received approval in China. In the present study, we evaluated the effects of HBI-8000 on ATL-derived cell lines and primary cells obtained from Japanese ATL patients. In most cases HBI-8000 induced apoptosis in both primary ATL cells and cell lines. In addition, findings obtained with DNA microarray suggested Bim activation and, interestingly, the contribution of the NLR family, pyrin domain containing 3 (NLRP3) inflammasome pathway in HBI-8000-induced ATL cell death. Further investigations using siRNAs confirmed that Bim contributes to HBI-8000-induced apoptosis. Our results provide a rationale for a clinical investigation of the efficacy of HBI-8000 in patients with ATL. Although the role of NLRP3 inflammasome activation in ATL cell death remains to be verified, HBI-8000 may be part of a novel therapeutic strategy for cancer based on the NLRP3 pathway

Simultaneous screening for JAK2 and calreticulin gene mutations in myeloproliferative neoplasms with high resolution melting

Introduction Recently, novel calreticulin (CALR) mutations were discovered in Janus kinase 2 (JAK2) non-mutated myelofibrosis (PMF) and essential thrombocythemia (ET) cases, with a frequency of 60?80%. We examined clinical correlations and CALR mutation frequency in our myeloproliferative neoplasms (MPN) cases, and introduce an effective test method for use in clinical practice. Methods We examined 177 samples previously investigated for the JAK2 mutation for differential diagnosis of MPN. JAK2 and CALR mutations were analyzed using melting curve analysis and microchip electrophoresis, respectively. Next, we constructed a test for simultaneous screening of the JAK2 and CALR mutations utilizing high resolution melting (HRM). Results Among 99 MPN cases, 60 possessed the JAK2 mutation alone. Of the 39 MPN cases without the JAK2 mutation, 14 were positive for the CALR mutation, all of which were ET. Using our novel screening test for the JAK2 and CALR mutations by HRM, the concordance rate of conventional analysis with HRM was 96% for the JAK2 mutation and 95% for the CALR mutation. Conclusion Our novel simultaneous screening test for the JAK2 and CALR gene mutations with HRM is useful for diagnosis of MPN