Key Points• ATRA and ATO affect NPM1 protein levels in AML cells and induce cell growth inhibition and apoptosis.• AML cells with mutated NPM1respond to ATRA/ATO, and this might be exploited therapeutically.Nucleophosmin (NPM1) mutations represent an attractive therapeutic target in acute myeloid leukemia (AML) because they are common (∼30% AML), stable, and behave as a founder genetic lesion. Oncoprotein targeting can be a successful strategy to treat AML, as proved in acute promyelocytic leukemia by treatment with all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO), which degrade the promyelocytic leukemia (PML)-retinoic acid receptor fusion protein. Adjunct of ATRA to chemotherapy was reported to be beneficial for NPM1-mutated AML patients. Leukemic cells with NPM1 mutation also showed sensibility to ATO in vitro. Here, we explore the mechanisms underlying these observations and show that ATO/ATRA induce proteasome-dependent degradation of NPM1 leukemic protein and apoptosis in NPM1-mutated AML cell lines and primary patients' cells. We also show that PML intracellular distribution is altered in NPM1-mutated AML cells and reverted by arsenic through oxidative stress induction. Interestingly, similarly to what was described for PML, oxidative stress also mediates ATO-induced degradation of the NPM1 mutant oncoprotein. Strikingly, NPM1 mutant downregulation by ATO/ATRA was shown to potentiate response to the anthracyclin daunorubicin. These findings provide experimental evidence for further exploring ATO/ATRA in preclinical NPM1-mutated AML in vivo models and a rationale for exploiting these compounds in chemotherapeutic regimens in clinics. (Blood. 2015;125(22):3455-3465)
Multiple Myeloma (MM) is a systemic hematologic disease due to uncontrolled proliferation of monoclonal plasma cells (PC) in bone marrow (BM). Emerging in other solid and liquid cancers, the host immune system and the microenvironment have a pivotal role for PC growth, proliferation, survival, migration, and resistance to drugs and are responsible for some clinical manifestations of MM. In MM, microenvironment is represented by the cellular component of a normal bone marrow together with extracellular matrix proteins, adhesion molecules, cytokines, and growth factors produced by both stromal cells and PC themselves. All these components are able to protect PC from cytotoxic effect of chemo- and radiotherapy. This review is focused on the role of immunome to sustain MM progression, the emerging role of myeloid derived suppressor cells, and their potential clinical implications as novel therapeutic target.
SummaryIn the attempt to find a peripheral blood biological marker that could mirror the dysregulated microenvironment of Hodgkin Lymphoma (HL), we analysed the amount of myeloid-derived suppressor cells (MDSC), including the three main sub-types (monocytic, granulocytic and CD34 + fraction). The absolute MDSC count was investigated in 60 consecutive newly diagnosed HL patients and correlated with clinical variables at diagnosis and outcome. Patients received standard-of-care chemotherapy with the exception of interim fluorodeoxyglucose positron emission tomography (PET-2)-positive patients, who were switched early to a salvage regimen. All MDSC subsets were increased in HL patients compared to normal subjects (P < 0Á0001) and were higher in non-responders. However, a strong prognostic significance was limited to immature (CD34 + ) MDSC. A cut-off level of 0Á0045 9 10 9 /l for CD34 + MDSC resulted in 89% (95% confidence interval [CI] 52-99%) sensitivity and 92% (95% CI 81-98%) specificity. The positive predictive value to predict progression-free survival was 0Á90 for PET-2 and 0Á98 for CD34 + MDSC count; the negative predictive value was 0Á57 for PET-2 and 0Á73 for CD34 + MDSC. PFS was significantly shorter in patients with more than 0Á0045 9 10 9 CD34 + MDSC cells/l at diagnosis and/or PET-2 positivity (P < 0Á0001). In conclusion, all circulating MDSC subsets are increased in HL; CD34 + MDSC predict short PFS, similarly to PET-2 but with the advantage of being available at diagnosis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.