Aggressive NK-cell leukemia (ANKL) is a rare form of NK cell neoplasm that is more prevalent among people from Asia and Central and South America. Patients usually die within days to months, even after receiving prompt therapeutic management. Here we performed the first comprehensive study of ANKL by integrating whole genome, transcriptome and targeted sequencing, cytokine array as well as functional assays. Mutations in the JAK-STAT pathway were identified in 48% (14/29) of ANKL patients, while the extracellular STAT3 stimulator IL10 was elevated by an average of 56-fold (P < 0.0001) in the plasma of all patients examined. Additional frequently mutated genes included TP53 (34%), TET2 (28%), CREBBP (21%) and MLL2 (21%). Patient NK leukemia cells showed prominent activation of STAT3 phosphorylation, MYC expression and transcriptional activities in multiple metabolic pathways. Functionally, STAT3 activation and MYC expression were critical for the proliferation and survival of ANKL cells. STAT signaling regulated the MYC transcription program, and both STAT signaling and MYC transcription were required to maintain the activation of nucleotide synthesis and glycolysis. Collectively, the JAK-STAT pathway represents a major target for genomic alterations and IL10 stimulation in ANKL. This newly discovered JAK/STAT-MYC-biosynthesis axis may provide opportunities for the development of novel therapeutic strategies in treating this subtype of leukemia.

Recurrent mutations of isocitrate dehydrogenase isoforms 1 and 2 (IDH1 and IDH2) have recently been studied in adult patients with acute myeloid leukemia (AML). A meta-analysis was performed to demonstrate their controversial prognostic impacts. The associations of IDH1 or IDH2 mutations with other molecular abnormalities were also investigated. In patients with AML, IDH1/2 mutations were significantly associated with normal karyotype and isolated trisomy 8 (p < .05). After adjusting for well-studied prognostic factors, IDH1 mutation seems to be associated with subtle but significantly inferior event-free survival (EFS) (p = 0.02) and possible adverse overall survival (OS) (p = 0.13) in patients with AML, especially in the favorable genotype subset with mutated NPM1 but without FLT3-ITD mutation (p < 0.05). Longer OS (p = 0.01) and better EFS tendency (p = 0.18) are implicated in patients with IDH2 mutations, which suggests that IDH2 mutations appear to confer a favorable prognosis. Moreover, IDH1 and IDH2 mutations may play a more important role in abnormal cytogenetics subgroups such as isolated trisomy 8. Screening of IDH1/2 mutations could help to identify patients at high risk within some subsets of AML.

ObjectivesVarious studies have investigated the prognostic value of C-MYC aberrations in diffuse large B-cell lymphoma (DLBCL). However, the role of C-MYC as an independent prognostic factor in clinical practice remains controversial. A systematic review and meta-analysis were performed to clarify the clinical significance of C-MYC aberrations in DLBCL patients.MethodsThe pooled hazard ratios (HRs) for overall survival (OS) and event-free survival (EFS) were calculated as the main effect size estimates. The procedure was conducted according to the Cochrane handbook and PRISMA guidelines, including the use of a heterogeneity test, publication bias assessment, and meta-regression, as well as subgroup analyses.ResultsTwenty-four eligible studies enrolling 4662 patients were included in this meta-analysis. According to the nature of C-MYC aberrations (gene, protein, and mRNA), studies were divided into several subgroups. For DLBCL patients with C-MYC gene abnormalities, the combined HR was 2.22 (95% confidence interval, 1.89 to 2.61) for OS and 2.29 (95% confidence interval, 1.81 to 2.90) for EFS, compared to patients without C-MYC gene abnormalities. For DLBCL patients with overexpression of C-MYC protein and C-MYC mRNA, pooled HRs for OS were 2.13 and 1.62, respectively. C-MYC aberrations appeared to play an independent role among other well-known prognostic factors in DLBCL. Addition of rituximab could not overcome the inferior prognosis conferred by C-MYC.ConclusionThe present systematic review and meta-analysis confirm the prognostic value of C-MYC aberrations. Screening of C-MYC should have definite prognostic meaning for DLBCL stratification, thus guaranteeing a more tailored therapy.

Aberrant DNA methylation patterns in leukemia might be exploited for therapeutic targeting. In this study, we employed a genetically deficient mouse model to explore the role of the methylated DNA binding protein MBD2 in normal and malignant hematopoiesis. MBD2 ablation led to diminished lymphocytes. Functional defects of the lymphoid compartment were also observed after reconstitution of MBD2-deficient hematopoietic stem cells (HSC). In an established model of Notch1-driven T-cell acute lymphoblastic leukemia (T-ALL), MBD2 ablation impeded malignant progression and maintenance by attenuating the Wnt signaling pathway. In clinical specimens of human T-ALL, Wnt signaling pathway signatures were significantly enhanced and positively correlated with the expression and function of MBD2. Furthermore, a number of typical Wnt signaling inhibitory genes were abnormally hypermethylated in primary human T-ALL. Abnormal activation of Wnt signaling in T-ALL was switched off by MBD2 deletion, partially by reactivating epigenetically silenced Wnt signaling inhibitors. Taken together, our results define essential roles for MBD2 in lymphopoiesis and T-ALL and suggest MBD2 as a candidate therapeutic target in T-ALL. This study highlights a methylated DNA binding protein as a candidate therapeutic target to improve the treatment of T-cell acute lymphoblastic leukemias, as a new starting point for developing epigenetic therapy in this and other lymphoid malignancies. .

Aberrant methylation of tumour suppressor genes is associated with the progression to a blast crisis in chronic myeloid leukaemia (CML). Methyl-CpG-binding domain protein 2 (MBD2) has been studied as a "reader" of DNA methylation in many cancers, but its role in CML is unclear. We constructed cell models of a homozygous deletion mutation of MBD2 using gene-editing technology in K562 cells and BV173 cells. Here, we demonstrated that the deletion of MBD2 inhibited cell proliferation capacity in vitro. MBD2 deletion also significantly inhibited K562 cell proliferation in a xenograft tumour model in vivo. Additionally, the JAK2/STAT3 signalling pathway, which is abnormally active in CML, was inhibited by MBD2 deletion, and MBD2 deletion could up-regulate the expression of SHP1. In conclusion, our findings suggest that MBD2 is a candidate therapeutic strategy for the CML blast phase.

Internal tandem duplication (ITD) mutations of FMS-like tyrosine kinase-3 (FLT3) are the most frequent genetic alterations in acute myeloid leukemia (AML) and predict a poor prognosis. FLT3 tyrosine kinase inhibitors (TKIs) provide short-term clinical responses, but the long-term prognosis of FLT3/ITD + AML patients remains poor. Notch signaling is important in numerous types of tumors. However, the role of Notch signaling in FLT3/ITD + AML remains to be elucidated. In the current study, we found that Notch signaling was activated upon FLT3-TKI treatment in FLT3/ITD + cell lines and primary cells. As Notch signaling can be blocked by γ-secretase inhibitors (GSIs), we examined the combinatorial antitumor efficacy of FLT3-TKIs and GSIs against FLT3/ITD + AML and explored the underlying molecular mechanisms. As a result, we observed synergistic cytotoxic effects, and the treatment preferentially reduced cell proliferation and induced apoptosis in FLT3/ITD + AML cell lines and in primary AML cells. Furthermore, the combination of FLT3-TKI and GSI eradicated leukemic cells and prolonged survival in an FLT3/ITD + patient-derived xenograft AML model. Mechanistically, differential expression analysis suggested that CXCR3 may be partially responsible for the observed synergy, possibly through ERK signaling. Our findings suggest that combined therapies of FLT3-TKIs with GSI may be exploited as a potential therapeutic strategy to treat FLT3/ITD + AML.

The paired box domain gene 5 (PAX5) is frequently altered in both childhood and adult B-cell acute lymphoblastic leukemia, and takes part in leukemogenesis. We analyzed data from the database of Gene Expression Omnibus (accession number: GSE11877) using bioinformatical and statistical methods. The results showed that cases of PAX5 alteration can cluster using unsupervised clustering algorithms, and one gene, zinc and ring finger 1 (ZNRF1), was characterized and validated by quantitative RT-PCR. ZNRF1 may be associated with leukemogenesis of ALL with PAX5 alteration.

A homocysteine-independent role for B-group vitamins on venous thrombosis (VT) development has been reported. However, related research findings remain inconsistent. PUBMED, EMBASE, and COCHRANE databases were searched to collect information on all eligible studies to make a meta-analysis about the relationship between B-group vitamins and VT. Literature search results did not suggest a correlation between thiamin, pantothenic acid, niacin, or riboflavin with VT. Based on their correlations in the literature, folic acid, vitamin B12, B6 were considered in the meta-analysis and systematic review. Significant standardized mean differences were obtained for plasma folic acid (-0.55; 95% CI, -0.75 to -0.36) and vitamin B12 (-0.34; 95% CI, -0.55 to -0.13). Reduced levels of folic acid and vitamin B12 may be independent risk factors of VT. Moreover, a qualitative systematic review indicated that low level of vitamin B6 was an independent risk factor of VT. Randomized clinical studies of B-group vitamins supplementation showed varying results on VT prevention. Multivitamin supplementation for VT prevention, regardless of homocysteine level, would be of interest. Further prospective clinical studies are needed to provide additional evidence on the clinical benefits of B-group vitamin supplementation for VT.