The associations of Janus kinase-2 (JAK2) A830G polymorphism and the treatment outcomes in patients with acute myeloid leukemia

Tumor microenvironment: a prospective target of natural alkaloids for cancer treatment

Malignant tumor has become one of the major diseases that seriously endangers human health. Numerous studies have demonstrated that tumor microenvironment (TME) is closely associated with patient prognosis. Tumor growth and progression are strongly dependent on its surrounding tumor microenvironment, because the optimal conditions originated from stromal elements are required for cancer cell proliferation, invasion, metastasis and drug resistance. The tumor microenvironment is an environment rich in immune/inflammatory cells and accompanied by a continuous, gradient of hypoxia and pH. Overcoming immunosuppressive environment and boosting anti-tumor immunity may be the key to the prevention and treatment of cancer. Most traditional Chinese medicine have been proved to have good anti-tumor activity, and they have the advantages of better therapeutic effect and few side effects in the treatment of malignant tumors. An increasing number of studies are giving evidence that alkaloids extracted from traditional Chinese medicine possess a significant anticancer efficiency via regulating a variety of tumor-related genes, pathways and other mechanisms. This paper reviews the anti-tumor effect of alkaloids targeting tumor microenvironment, and further reveals its anti-tumor mechanism through the effects of alkaloids on different components in tumor microenvironment.

Inactivated STAT5 pathway underlies a novel inhibitory role of EBF1 in chronic lymphocytic leukemia

B-cell chronic lymphocytic leukemia (CLL) is a disease caused by gradual accumulation of functionally incompetent lymphocytes. The majority of CLL cases are accompanied by chemoresistance. Early B cell factor 1 (EBF1) is a crucial contributor to B-cell lymphopoiesis. This study is to explore the effect of EBF1 on CLL cell progression and its involvement in regulating the signal transducers and activators of transcription 5 (STAT5) pathway. We conducted a correlation analysis between EBF1 and the clinical characteristics of CLL patients. Subsequently, EBF1 was overexpressed by transfection with EBF1 overexpression plasmid and the STAT5 pathway was also blocked by treatment with SH-4-54 in isolated CD20⁺ B lymphocytes to investigate their roles in the regulation of cellular functions. STAT5, Janus kinase 2 (JAK2) expression and their phosphorylation levels were determined by quantitative PCR and Western blot analyses. The in vivo effects of EBF1 on tumor growth were evaluated using a xenotransplant model. Downregulation of EBF1 was observed in CD20⁺ B lymphocytes of CLL patients. EBF1 overexpression disrupted the activation of STAT5 pathway, as evidenced by decreased expression and phosphorylation levels of STAT5 and JAK2. Furthermore, overexpression of EBF1 repressed viability and cell cycle entry, and increased apoptosis of CD20⁺ B lymphocytes by inhibiting the STAT5 pathway. Finally, EBF1 exerted antitumor effects in nude mice. Overall, our study elucidates the inhibitory role of EBF1 in CLL through inactivation of the STAT5 pathway, which may provide new targets for CLL treatment.

Recipient and donor JAK2 46/1 haplotypes are associated with acute graft-versus-host disease following allogeneic hematopoietic stem cell transplantation

Several genetic polymorphisms have been implicated to affect the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT). The role of cytokines in acute graft-versus-host disease (aGvHD) is well established and many of the involved cytokines signal through the Janus kinase (JAK) pathways. In this study, we assessed the association of recipient and donor JAK2 46/1 haplotypes and allo-HSCT outcome in a cohort of 124 acute myeloid leukemia patients. Both, recipient and donor 46/1 haplotypes significantly affected aGvHD grades II-IV development (p = 0.006 and p = 0.031, respectively), furthermore the influence of the haplotypes seemed to be additive. In multivariate analyses the recipient haplotype remained independently related (p = 0.012) to aGvHD, while the donor not (p = 0.08). We observed significantly less relapses among haplotype carriers (p = 0.004), but overall survival did not differ (p = 0.732). Our findings suggest that recipient and donor JAK2 46/1 haplotypes might be involved in the regulation of aGvHD.

Mass spectrometry in leukemia research and treatment

Mass spectrometry (MS) is a complex analytical chemistry tool that allows qualitative and quantitative assessments of the components of complex chemical compounds. Applications of MS in medicine include the identification and quantification of drugs and metabolites; identification of proteins, biopolymers and disease markers and investigation of differential protein expression and proteins altered by mutations and/or post-translational changes. A variety of MS methods and technologies now play valuable and expanding roles in the diagnosis and monitoring of acute leukemia, as well as in identification of therapeutic targets and biomarkers, drug discovery, and other important areas of leukemia research. The objective of this review is to present a clinically oriented review of the roles of MS in the research, diagnosis and therapy of acute leukemia.

Investigation and analysis of single nucleotide polymorphisms in Janus kinase/signal transducer and activator of transcription genes with leukemia

Aberrant activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway may predispose to leukemia due to deregulation of proliferation, differentiation or apoptosis. This study was conducted to investigate whether any association exists between genetic polymorphisms in the JAK2, STAT3 and STAT5 genes and individual susceptibility to leukemia. A case-control study was carried out using a Chinese sample set with 344 cases of leukemia and 346 controls matched by age and ethnicity. Genomic DNA was assayed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) on 13 single nucleotide polymorphisms (SNPs). Genotype analyses showed that two SNPs, namely rs17886724 and rs2293157 located in STAT3 and STAT5, respectively, were significantly associated with leukemia (p < 0.05 for all). Interaction analyses of SNPs (rs17886724|rs2293157; rs11079041| rs2293157) showed that there were inferior associations in chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML) compared to the control group (0.1 > p > 0.05). Linkage disequilibrium existed between rs11079041 and rs2293157 in both leukemia and control groups (r(2) = 0.7). The haplotypes displayed significant association between rs11079041 and rs2293157 in both leukemia and control groups (p < 0.05). The accuracy rate of the support vector machine (SVM) classification model in making a prediction of leukemia was 97%. The results indicated that STAT3 and STAT5 gene SNPs may be prognostic of leukemia.

JAK-1 rs2780895 C-related genotype and allele but not JAK-1 rs10789166, rs4916008, rs2780885, rs17127114, and rs3806277 are associated with higher susceptibility to asthma

BACKGROUND

Asthma, one major respiratory consequence, might be caused by a complex interaction between multiple candidate genes and environmental factors. Herein, we aimed to investigate whether Janus kinase (JAK)-1 gene polymorphisms are associated with asthma susceptibility.

MATERIALS AND METHODS

Patients were divided into two groups: (1) asthma (n=117) and (2) nonasthma (n=60). The JAK-1 polymorphisms (rs2780895, rs10789166, rs4916008, rs2780885, rs17127114, and rs3806277) were amplified by polymerase chain reaction and detected by electrophoresis after restriction enzyme (HpyCH4IV, Tsp45I, HpaII, XmnI, MspI, and HpaII) digestions. Genotypes, allelic frequencies, and association of haplotypes in both groups were compared.

RESULTS

JAK-1 rs2780895 gene polymorphism is associated with susceptibility to asthma. Distributions of JAK-1 rs2780895*CC/CT/TT and C/T allele in both groups are: (1) 80/4/16% and 82/18%; (2) 48/45/7% and 71/29%. Other 5 JAK-1 SNPs (rs10789166, rs4916008, rs2780885, rs17127114, and rs3806277) are not associated with asthma susceptibilities. Distributions of JAK-1 rs10789166*AA/AG/GG, rs4916008*CC/CT/TT, rs2780885*CC/CT/TT, rs17127114*AA/AG/GG, rs3806277*AA/AG/GG in both groups are: (1) 50/40/10%, 42/49/9%, 50/40/10%, 9/37/54%, 8/35/57%; (2) 43/50/7%, 40/50/10%, 50/43/7%, 7/48/45%, 6/42/52%. Haplotype analyses for JAK-1 gene polymorphisms (rs2780895-rs10789166-rs4916008-rs2780885-rs17127114-rs3806277) revealed that JAK-1 haplotypes are not associated with asthma susceptibilities.

CONCLUSIONS

JAK-1 rs2780895 C-related genotype and allele are associated with higher susceptibility to asthma. JAK-1 rs10789166, rs4916008, rs2780885, rs17127114, and rs3806277 single-nucleotide polymorphisms are not associated with asthma development. Some JAK-related genetic variations might be associated with asthma pathogenesis, which deserve further surveys.

The prognostic impact of germline 46/1 haplotype of Janus kinase 2 in cytogenetically normal acute myeloid leukemia

BACKGROUND

Prognostic risk stratification according to acquired or inherited genetic alterations has received increasing attention in acute myeloid leukemia in recent years. A germline Janus kinase 2 haplotype designated as the 46/1 haplotype has been reported to be associated with an inherited predisposition to myeloproliferative neoplasms, and also to acute myeloid leukemia with normal karyotype. The aim of this study was to assess the prognostic impact of the 46/1 haplotype on disease characteristics and treatment outcome in acute myeloid leukemia.

DESIGN AND METHODS

Janus kinase 2 rs12343867 single nucleotide polymorphism tagging the 46/1 haplotype was genotyped by LightCycler technology applying melting curve analysis with the hybridization probe detection format in 176 patients with acute myeloid leukemia under 60 years diagnosed consecutively and treated with curative intent.

RESULTS

The morphological subtype of acute myeloid leukemia with maturation was less frequent among 46/1 carriers than among non-carriers (5.6% versus 17.2%, P = 0.018, cytogenetically normal subgroup: 4.3% versus 20.6%, P = 0.031), while the morphological distribution shifted towards the myelomonocytoid form in 46/1 haplotype carriers (28.1% versus 14.9%, P = 0.044, cytogenetically normal subgroup: 34.0% versus 11.8%, P = 0.035). In cytogenetically normal cases of acute myeloid leukemia, the 46/1 carriers had a considerably lower remission rate (78.7% versus 94.1%, P = 0.064) and more deaths in remission or in aplasia caused by infections (46.8% versus 23.5%, P = 0.038), resulting in the 46/1 carriers having shorter disease-free survival and overall survival compared to the 46/1 non-carriers. In multivariate analysis, the 46/1 haplotype was an independent adverse prognostic factor for disease-free survival (P = 0.024) and overall survival (P = 0.024) in patients with a normal karyotype. Janus kinase 2 46/1 haplotype had no impact on prognosis in the subgroup with abnormal karyotype.

CONCLUSIONS

Janus kinase 2 46/1 haplotype influences morphological distribution, increasing the predisposition towards an acute myelomonocytoid form. It may be a novel, independent unfavorable risk factor in acute myeloid leukemia with a normal karyotype.