Leukemia
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Oncogenic NRAS and KRAS mutations are prevalent in human juvenile and chronic myelomonocytic leukemia (JMML/CMML). However, additional genetic mutations cooperating with oncogenic RAS in JMML/ CMML progression and/or their transformation to acute myeloid leukemia (AML) remain largely unknown. Here we tested the potential genetic interaction of DNMT3A mutations and oncogenic RAS mutations in leukemogenesis. ⋯ Moreover, ~33% of animals developed an AML-like disease, which is driven by Kras(G12D/+); Dnmt3a(-/-) MPs. Consistent with our result, COSMIC database mining demonstrates that the combination of oncogenic RAS and DNMT3A mutations exclusively occurred in patients with JMML, CMML or AML. Our results suggest that DNMT3A mutations and oncogenic RAS cooperate to regulate hematopoietic stem and progenitor cells and promote myeloid malignancies.
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Randomized Controlled Trial Multicenter Study Comparative Study
Phase III trial of bortezomib, cyclophosphamide and dexamethasone (VCD) versus bortezomib, doxorubicin and dexamethasone (PAd) in newly diagnosed myeloma.
We aimed at demonstrating non-inferiority of bortezomib/cyclophosphamide/dexamethasone (VCD) compared to bortezomib/doxorubicin/dexamethasone (PAd) induction therapy with respect to very good partial response rates or better (⩾VGPR) in 504 newly diagnosed, transplant-eligible multiple myeloma patients. VCD was found to be non-inferior to PAd with respect to ⩾VGPR rates (37.0 versus 34.3%, P=0.001). The rates of progressive disease (PD) were 0.4% (VCD) versus 4.8% (PAd; P=0.003). ⋯ Stem cell collection was not impeded by VCD. VCD is as effective as PAd in terms of achieving ⩾VGPR rates with fewer PD and has a favorable toxicity profile. Therefore, VCD is preferable to PAd as induction therapy.
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CXCR4(WHIM) somatic mutations are common Waldenstrom's Macroglobulinemia (WM), and are associated with clinical resistance to ibrutinib. We engineered WM cells to express the most common WHIM (Warts, Hypogammaglobulinemia, Infections and Myelokathexis), CXCR(S338X) mutation in WM. Following SDF-1a stimulation, CXCR4(S338X) WM cells exhibited decreased receptor internalization, enhanced and sustained AKT kinase (AKT) and extracellular regulated kinase (ERK) signaling, decreased poly (ADP-ribose) polymerase and caspase 3 cleavage, and decreased Annexin V staining versus CXCR4 wild-type (WT) cells. ⋯ Enhanced bone marrow pAKT staining was also evident in CXCR4(WHIM) versus CXCR4(WT) WM patients, and remained active despite ibrutinib therapy in CXCR4(WHIM) patients. Last, CXCR4(S338X) WM cells showed varying levels of resistance to other WM relevant therapeutics, including bendamustine, fludarabine, bortezomib and idelalisib in the presence of SDF-1a. These studies demonstrate a functional role for CXCR4(WHIM) mutations, and provide a framework for investigation of CXCR4 inhibitors in WM.