JAK1

Gene Summary

Gene:JAK1; Janus kinase 1
Aliases: JTK3, JAK1A, JAK1B
Location:1p32.3-p31.3
Summary:Janus kinase 1 (JAK1), is a member of a new class of protein-tyrosine kinases (PTK) characterized by the presence of a second phosphotransferase-related domain immediately N-terminal to the PTK domain. The second phosphotransferase domain bears all the hallmarks of a protein kinase, although its structure differs significantly from that of the PTK and threonine/serine kinase family members. JAK1 is a large, widely expressed membrane-associated phosphoprotein. JAK1 is involved in the interferon-alpha/beta and -gamma signal transduction pathways. The reciprocal interdependence between JAK1 and TYK2 activities in the interferon-alpha pathway, and between JAK1 and JAK2 in the interferon-gamma pathway, may reflect a requirement for these kinases in the correct assembly of interferon receptor complexes. These kinases couple cytokine ligand binding to tyrosine phosphorylation of various known signaling proteins and of a unique family of transcription factors termed the signal transducers and activators of transcription, or STATs. [provided by RefSeq, Jul 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:tyrosine-protein kinase JAK1
HPRD
Source:NCBIAccessed: 06 August, 2015

Ontology:

What does this gene/protein do?
Show (22)
Pathways:What pathways are this gene/protein implicaed in?
Show (14)

Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 06 August 2015 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Transcription Factors
  • Suppressor of Cytokine Signaling Proteins
  • Signal Transduction
  • JAK1
  • Mutation
  • DNA-Binding Proteins
  • Acute Lymphocytic Leukaemia
  • Myeloproliferative Disorders
  • Transduction
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma
  • STAT1 Transcription Factor
  • Tyrphostins
  • T-Lymphocytes
  • Zinc Fingers
  • beta Catenin
  • Chromosome 1
  • Gene Expression Profiling
  • Receptors, Cytokine
  • Transforming Growth Factor beta2
  • Transcription
  • JAK2
  • Apoptosis
  • Protein-Tyrosine Kinases
  • Stomach Cancer
  • Tumor Suppressor Proteins
  • Tumor Markers
  • Messenger RNA
  • STAT3 Transcription Factor
  • Thrombocythemia, Essential
  • Single-Stranded Conformational Polymorphism
  • Janus Kinase 3
  • Trans-Activators
  • Protein-Serine-Threonine Kinases
  • Cell Proliferation
  • Transcription Factor 7-Like 1 Protein
  • Point Mutation
  • Janus Kinases
  • Cancer Gene Expression Regulation
  • Sequence Homology
  • Recurrence
  • Phosphorylation
Tag cloud generated 06 August, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: JAK1 (cancer-related)

Crescenzo R, Abate F, Lasorsa E, et al.
Convergent mutations and kinase fusions lead to oncogenic STAT3 activation in anaplastic large cell lymphoma.
Cancer Cell. 2015; 27(4):516-32 [PubMed] Related Publications
A systematic characterization of the genetic alterations driving ALCLs has not been performed. By integrating massive sequencing strategies, we provide a comprehensive characterization of driver genetic alterations (somatic point mutations, copy number alterations, and gene fusions) in ALK(-) ALCLs. We identified activating mutations of JAK1 and/or STAT3 genes in ∼20% of 88 [corrected] ALK(-) ALCLs and demonstrated that 38% of systemic ALK(-) ALCLs displayed double lesions. Recurrent chimeras combining a transcription factor (NFkB2 or NCOR2) with a tyrosine kinase (ROS1 or TYK2) were also discovered in WT JAK1/STAT3 ALK(-) ALCL. All these aberrations lead to the constitutive activation of the JAK/STAT3 pathway, which was proved oncogenic. Consistently, JAK/STAT3 pathway inhibition impaired cell growth in vitro and in vivo.

Lee JH, Kim C, Kim SH, et al.
Farnesol inhibits tumor growth and enhances the anticancer effects of bortezomib in multiple myeloma xenograft mouse model through the modulation of STAT3 signaling pathway.
Cancer Lett. 2015; 360(2):280-93 [PubMed] Related Publications
Aberrant activation of signal transducer and activator of transcription 3 (STAT3) is frequently observed in multiple myeloma (MM) cancer and can upregulate the expression of several genes involved in proliferation, survival, metastasis, and angiogenesis. The effect of farnesol (FOH) on STAT3 activation, associated protein kinases, its regulated gene products, cellular proliferation, and apoptosis was examined. The in vivo effect of FOH on the growth of human MM xenograft tumors alone and in combination with bortezomib (Bor) in athymic nu/nu female mice was also investigated. We found that FOH suppressed both constitutive and inducible STAT3 activation at Tyr705 in MM cells. The suppression of STAT3 was mediated through the inhibition of activation of upstream JAK1, JAK2, and c-Src kinases. Also, treatment with the protein tyrosine phosphatase (PTP) inhibitor, pervanadate treatment reversed the FOH-induced down-regulation of STAT3, possibly indicating the involvement of a PTP. Indeed, we found that FOH treatment induces the increased expression of SHP-2 protein and knockdown of the SHP-2 gene by small interfering RNA suppressed the ability of FOH to inhibit STAT3 activation. FOH inhibited proliferation and significantly potentiated the apoptotic effects of bortezomib (Bor) in U266 cells. When administered intraperitoneally, FOH enhanced Bor-induced growth suppression of human MM xenograft tumors in athymic nu/nu female mice. Our results suggest that FOH is a novel blocker of STAT3 signaling pathway and exerts both anti-proliferative and apoptotic activities in MM in vitro and in vivo.

Moon SU, Kang MH, Sung JH, et al.
Effect of Smad3/4 on chemotherapeutic drug sensitivity in colorectal cancer cells.
Oncol Rep. 2015; 33(1):185-92 [PubMed] Related Publications
Smad3 and Smad4 are signaling mediators in the transforming growth factor β (TGFβ) pathway and play a major role in the progression and migration of many types of cancers. The TGFβ pathway is correlated with resistance against both targeted and conventional chemotherapeutic drugs. The aim of this study was to determine the effect of Smad3/4 on drug sensitivity in chemotherapy-resistant colorectal cancer (CRC) cells. We isolated the TGFβ-mediated chemoresistant CRC cell line DLD1-5FU-C10, which showed high expression of Smad3/4 and p21. In order to analyze the influence of Smad3/4 on drug sensitivity in DLD1-5FU-C10 cells, we knocked down Smad3/4 using small interfering RNAs (siRNA). The results showed similar drug sensitivity between the DLD1‑5FU-C10 and the DLD1 control cells and reduced p21 expression. In addition, we found a significant increase in the levels of 3 TGFβ downstream factors: interleukin 6 (IL6), plasminogen activator (PLAU) and prostaglandin-endoperoxide synthase 2 (PTGS2). Furthermore, we showed that Smad3/4 regulated the JAK1/STAT3 pathway via IL6 in the chemoresistant CRC cell line. In conclusion, we identified Smad3/4 as a novel drug sensitivity regulator in TGFβ-mediated chemotherapy-resistant CRC cells. Our results suggest that Smad3/4 regulate p-STAT3 signaling by IL6 and p21 and highlight an important role for STAT3 signaling in Smad3/4 regulated drug sensitivity in chemoresistant CRC cells.

Wang X, Breeze A, Kulka M
N-3 polyunsaturated fatty acids inhibit IFN-γ-induced IL-18 binding protein production by prostate cancer cells.
Cancer Immunol Immunother. 2015; 64(2):249-58 [PubMed] Related Publications
Prostate cancer cells can produce IL-18 binding protein (IL-18BP) in response to interferon-γ (IFN-γ), which may function to neutralize IL-18, an anti-tumor factor formerly known as IFN-γ inducing factor. The consumption of n-3 polyunsaturated fatty acids (PUFAs) has been associated with a lower risk of certain types of cancer including prostate cancer, although the precise mechanisms of this effect are poorly understood. We hypothesized that n-3 PUFAs could modify IL-18BP production by prostate cancer cells by altering IFN-γ receptor-mediated signal transduction. Here, we demonstrate that n-3 PUFA treatment significantly reduced IFN-γ-induced IL-18BP production by DU-145 and PC-3 prostate cancer cells by inhibiting IL-18BP mRNA expression and was associated with a reduction in IFN-γ receptor expression. Furthermore, IFN-γ-induced phosphorylation of Janus kinase 1 (JAK1), signal transducers and activators of transcription 1 (STAT1), extracellular signal-regulated kinases 1/2 (ERK1/2), and P38 were suppressed by n-3 PUFA treatment. By contrast, n-6 PUFA had no effect on IFN-γ receptor expression, but decreased IFN-γ-induced IL-18BP production and IFN-γ stimulation of JAK1, STAT1, ERK1/2, and JNK phosphorylation. These data indicate that both n-3 and n-6 PUFAs may be beneficial in prostate cancer by altering IFN-γ signaling, thus inhibiting IL-18BP production and thereby rendering prostate cancer cells more sensitive to IL-18-mediated immune responses.

Slattery ML, Wolff RK, Lundgreen A
A pathway approach to evaluating the association between the CHIEF pathway and risk of colorectal cancer.
Carcinogenesis. 2015; 36(1):49-59 [PubMed] Article available free on PMC after 01/01/2016 Related Publications
Inflammation, hormones and energy-related factors have been associated with colorectal cancer (CRC) and it has been proposed that convergence and interactions of these factors importantly influence CRC risk. We have previously hypothesized that genetic variation in the CHIEF (convergence of hormones, inflammation and energy-related factors) pathway would influence risk of CRC. In this paper, we utilize an Adaptive Rank Truncation Product (ARTP) statistical method to determine the overall pathway significance and then use that method to identify the key elements within the pathway associated with disease risk. Data from two population-based case-control studies of colon (n = 1555 cases and 1956 controls) and rectal (n = 754 cases and 959 controls) cancer were used. We use ARTP to estimate pathway and gene significance and polygenic scores based on ARTP findings to further estimate the risk associated with the pathway. Associations were further assessed based on tumor molecular phenotype. The CHIEF pathway was statistically significant for colon cancer (P(ARTP)= 0.03) with the most significant interferons (P(ARTP) = 0.0253), JAK/STAT/SOCS (P(ARTP) = 0.0111), telomere (P(ARTP) = 0.0399) and transforming growth factor β (P(ARTP) = 0.0043) being the most significant subpathways for colon cancer. For rectal cancer, interleukins (P(ARTP) = 0.0235) and selenoproteins (P ARTP = 0.0047) were statistically significant although the pathway overall was of borderline significance (P(ARTP) = 0.06). Interleukins (P(ARTP) = 0.0456) and mitogen-activated protein kinase (P(ARTP) = 0.0392) subpathways were uniquely significant for CpG island methylator phenotype-positive colon tumors. Increasing number of at-risk alleles was significantly associated with both colon [odds ratio (OR) = 6.21, 95% confidence interval (CI): 4.72, 8.16] and rectal (OR = 7.82, 95% CI: 5.26, 11.62) cancer. We conclude that elements of the CHIEF pathway are important for CRC risk.

Mohan CD, Bharathkumar H, Bulusu KC, et al.
Development of a novel azaspirane that targets the Janus kinase-signal transducer and activator of transcription (STAT) pathway in hepatocellular carcinoma in vitro and in vivo.
J Biol Chem. 2014; 289(49):34296-307 [PubMed] Article available free on PMC after 05/12/2015 Related Publications
Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates genes involved in cell growth, proliferation, and survival, and given its association with many types of cancers, it has recently emerged as a promising target for therapy. In this work, we present the synthesis of N-substituted azaspirane derivatives and their biological evaluation against hepatocellular carcinoma (HCC) cells (IC50 = 7.3 μm), thereby identifying 2-(1-(4-(2-cyanophenyl)1-benzyl-1H-indol-3-yl)-5-(4-methoxy-phenyl)-1-oxa-3-azaspiro(5,5) undecane (CIMO) as a potent inhibitor of the JAK-STAT pathway with selectivity over normal LO2 cells (IC50 > 100 μm). The lead compound, CIMO, suppresses proliferation of HCC cells and achieves this effect by reducing both constitutive and inducible phosphorylation of JAK1, JAK2, and STAT3. Interestingly, CIMO displayed inhibition of Tyr-705 phosphorylation, which is required for nuclear translocation of STAT3, but it has no effect on Ser-727 phosphorylation. CIMO accumulates cancer cells in the sub-G1 phase and decreases STAT3 in the nucleus and thereby causes down-regulation of genes regulated via STAT3. Suppression of STAT3 phosphorylation by CIMO and knockdown of STAT3 mRNA using siRNA transfection displayed a similar effect on the viability of HCC cells. Furthermore, CIMO significantly decreased the tumor development in an orthotopic HCC mouse model through the modulation of phospho-STAT3, Ki-67, and cleaved caspase-3 in tumor tissues. Thus, CIMO represents a chemically novel and biologically in vitro and in vivo validated compound, which targets the JAK-STAT pathway as a potential cancer treatment.

Ye F, Tang C, Shi W, et al.
A MDM2-dependent positive-feedback loop is involved in inhibition of miR-375 and miR-106b induced by Helicobacter pylori lipopolysaccharide.
Int J Cancer. 2015; 136(9):2120-31 [PubMed] Related Publications
Dysregulation of microRNAs (miRNAs) has been linked to virulence factors of Helicobacter pylori and shown to contribute to the progression of gastric cancer. However, the mechanisms of these processes remain poorly understood. The aim of this study was to investigate the mechanisms by which lipopolysaccharide (LPS), a virulence factor of H. pylori, regulates miR-375 and miR-106b expression in gastric epithelial cells. The results show that LPS from H. pylori 26695 downregulated the expression of miR-375 and miR-106b in gastric epithelial cells, and low levels of Dicer were also observed. Downregulation of miR-375 was found to increase expression of MDM2 with SP1 activation. Overexpression of MDM2 inhibited Dicer by repressing p63 to create a positive-feedback loop involving SP1/MDM2/p63/Dicer that leads to inhibition of miR-375 and miR-106b expression. In addition, we demonstrated that JAK1 and STAT3 were downstream target genes of miR-106b. H. pylori LPS also enhanced the tyrosine phosphorylation of JAK1, JAK2 and STAT3. Together, these results provide insight into the regulatory mechanisms of MDM2 on H. pylori LPS-induced specific miRNAs, and furthermore, suggest that gastric epithelial cells treated with H. pylori LPS may be susceptible to JAK/STAT3 signal pathway activation via inhibition of miR-375 and miR-106b.

Schwaab J, Knut M, Haferlach C, et al.
Limited duration of complete remission on ruxolitinib in myeloid neoplasms with PCM1-JAK2 and BCR-JAK2 fusion genes.
Ann Hematol. 2015; 94(2):233-8 [PubMed] Related Publications
Rearrangements of chromosome band 9p24 are known to be associated with JAK2 fusion genes, e.g., t(8;9)(p22;p24) with a PCM1-JAK2 and t(9;22)(p24;q11) with a BCR-JAK2 fusion gene, respectively. In association with myeloid neoplasms, the clinical course is aggressive, and in absence of effective conventional treatment options, long-term remission is usually only observed after allogeneic stem cell transplantation (ASCT). With the discovery of inhibitors of the JAK2 tyrosine kinase and based on encouraging in vitro and in vivo data, we treated two male patients with myeloid neoplasms and a PCM1-JAK2 or a BCR-JAK2 fusion gene, respectively, with the JAK1/JAK2 inhibitor ruxolitinib. After 12 months of treatment, both patients achieved a complete clinical, hematologic, and cytogenetic response. Non-hematologic toxicity was only grade 1 while no hematologic toxicity was observed. However, remission in both patients was only short-term, with relapse occurring after 18 and 24 months, respectively, making ASCT indispensable in both cases. This data highlight (1) the ongoing importance of cytogenetic analysis for the diagnostic work-up of myeloid neoplasms as it may guide targeted therapy and (2) remission under ruxolitinib may only be short-termed in JAK2 fusion genes but it may be an important bridging therapy prior to ASCT.

Jhunjhunwala S, Jiang Z, Stawiski EW, et al.
Diverse modes of genomic alteration in hepatocellular carcinoma.
Genome Biol. 2014; 15(8):436 [PubMed] Article available free on PMC after 05/12/2015 Related Publications
BACKGROUND: Hepatocellular carcinoma (HCC) is a heterogeneous disease with high mortality rate. Recent genomic studies have identified TP53, AXIN1, and CTNNB1 as the most frequently mutated genes. Lower frequency mutations have been reported in ARID1A, ARID2 and JAK1. In addition, hepatitis B virus (HBV) integrations into the human genome have been associated with HCC.
RESULTS: Here, we deep-sequence 42 HCC patients with a combination of whole genome, exome and transcriptome sequencing to identify the mutational landscape of HCC using a reasonably large discovery cohort. We find frequent mutations in TP53, CTNNB1 and AXIN1, and rare but likely functional mutations in BAP1 and IDH1. Besides frequent hepatitis B virus integrations at TERT, we identify translocations at the boundaries of TERT. A novel deletion is identified in CTNNB1 in a region that is heavily mutated in multiple cancers. We also find multiple high-allelic frequency mutations in the extracellular matrix protein LAMA2. Lower expression levels of LAMA2 correlate with a proliferative signature, and predict poor survival and higher chance of cancer recurrence in HCC patients, suggesting an important role of the extracellular matrix and cell adhesion in tumor progression of a subgroup of HCC patients.
CONCLUSIONS: The heterogeneous disease of HCC features diverse modes of genomic alteration. In addition to common point mutations, structural variations and methylation changes, there are several virus-associated changes, including gene disruption or activation, formation of chimeric viral-human transcripts, and DNA copy number changes. Such a multitude of genomic events likely contributes to the heterogeneous nature of HCC.

Zhang Z, Fye S, Borecki IB, Rader JS
Polymorphisms in immune mediators associate with risk of cervical cancer.
Gynecol Oncol. 2014; 135(1):69-73 [PubMed] Article available free on PMC after 01/10/2015 Related Publications
OBJECTIVE: The immune system is critical for controlling the progression of HPV cervical disease and the development of cancer. This study aimed to identify cervical cancer susceptibility alleles in candidate immune-modulating genes.
METHODS: Our family-based study involved a cohort of 641 probands (women with ICC/CIN III) and their biologic parents or siblings (641 trios). In the discovery phase (stage 1), involving 288 of the trios, 80 tag single nucleotide polymorphisms (SNPs) in 11 immune-modulating genes (IFNG, IFNGR1, IFNGR2, JAK1, JAK2, STAT1, STAT6, IL12A, TNF, LTA and LTB) were evaluated on the GoldenGate platform. We used the combined dataset for a total of 641 trios (stage 2) and the Taqman platform to validate the SNPs that had proved significant in the discovery dataset. The transmission disequilibrium test was used to detect significant shifts in allelic transmissions in the datasets.
RESULTS: Two SNPs in JAK2 and one SNP in STAT6 showed significant allelic association with cervical cancer in the stage 1 discovery dataset and were replicated in the larger joint analysis stage 2 dataset (JAK2 rs10815144, P=0.0029 and rs12349785, P=0.0058; and STAT6 rs3024971, P=0.0127). An additional SNP in exon 19 of JAK2 (rs2230724) was also examined in the combined dataset due to its strong linkage disequilibrium (LD) with rs10815144. It was also significant (P=0.0335).
CONCLUSIONS: Our results suggest an association of SNPs in JAK2 and STAT6 with cervical cancer. This association should be investigated in additional cervical cancer populations.

Siveen KS, Nguyen AH, Lee JH, et al.
Negative regulation of signal transducer and activator of transcription-3 signalling cascade by lupeol inhibits growth and induces apoptosis in hepatocellular carcinoma cells.
Br J Cancer. 2014; 111(7):1327-37 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
BACKGROUND: Constitutive activation of signal transducer and activator of transcription signalling 3 (STAT3) has been linked with survival, proliferation and angiogenesis in a wide variety of malignancies including hepatocellular carcinoma (HCC).
METHODS: We evaluated the effect of lupeol on STAT3 signalling cascade and its regulated functional responses in HCC cells.
RESULTS: Lupeol suppressed constitutive activation of STAT3 phosphorylation at tyrosine 705 residue effectively in a dose- and time-dependent manner. The phosphorylation of Janus-activated kinases (JAKs) 1 and 2 and Src was also suppressed by lupeol. Pervanadate treatment reversed the downregulation of phospho-STAT3 induced by lupeol, thereby indicating the involvement of a phosphatase. Indeed, we observed that treatment with lupeol increased the protein and mRNA levels of SHP-2, and silencing of SHP-2 abolished the inhibitory effects of lupeol on STAT3 activation. Treatment with lupeol also downregulated the expression of diverse STAT3-regulated genes and decreased the binding of STAT3 to VEGF promoter. Moreover, the proliferation of various HCC cells was significantly suppressed by lupeol, being associated with substantial induction of apoptosis. Depletion of SHP-2 reversed the observed antiproliferative and pro-apoptotic effects of lupeol.
CONCLUSIONS: Lupeol exhibited its potential anticancer effects in HCC through the downregulation of STAT3-induced pro-survival signalling cascade.

Lee HJ, Zhuang G, Cao Y, et al.
Drug resistance via feedback activation of Stat3 in oncogene-addicted cancer cells.
Cancer Cell. 2014; 26(2):207-21 [PubMed] Related Publications
Pathway-targeted cancer drugs can produce dramatic responses that are invariably limited by the emergence of drug-resistant cells. We found that many drug-treated "oncogene-addicted" cancer cells engage a positive feedback loop leading to Stat3 activation, consequently promoting cell survival and limiting overall drug response. This was observed in cancer cells driven by diverse activated kinases, including EGFR, HER2, ALK, and MET, as well as mutant KRAS. Specifically, MEK inhibition led to autocrine activation of Stat3 via the FGF receptor and JAK kinases, and pharmacological inhibition of MEK together with JAK and FGFR enhanced tumor regression. These findings suggest that inhibition of a Stat3 feedback loop may augment the response to a broad spectrum of drugs that target pathways of oncogene addiction.

Pritchett TL, Bader HL, Henderson J, Hsu T
Conditional inactivation of the mouse von Hippel-Lindau tumor suppressor gene results in wide-spread hyperplastic, inflammatory and fibrotic lesions in the kidney.
Oncogene. 2015; 34(20):2631-9 [PubMed] Related Publications
Mutations of the tumor suppressor gene von Hippel-Lindau (VHL) can lead to benign and malignant tumors, including clear-cell renal cell carcinoma (ccRCC). To understand the progression of ccRCC, we generated a novel mouse Vhlh conditional knockout, using Hoxb7-driven Cre that is specific for the collecting ducts and a subset of distal tubules. These mice exhibited wide-spread epithelial disruption and interstitial inflammation as early as 2 months of age with high penetrance. Lesions are cystic, show severe fibrosis and display significant hyperplasia. An abundance of infiltrating macrophages and lymphocytes was detected. Interestingly, the Vhlh mutant lesions could be rescued when Hif-1α, but not Hif-2α, was also knocked out. In addition, administration of a JAK1/2 kinase inhibitor alleviated the Vhlh knockout phenotypes. Taken together, these results suggest that HIF-1α-dependent inflammation and fibrosis may be an early event in the development of ccRCC.

Lupardus PJ, Ultsch M, Wallweber H, et al.
Structure of the pseudokinase-kinase domains from protein kinase TYK2 reveals a mechanism for Janus kinase (JAK) autoinhibition.
Proc Natl Acad Sci U S A. 2014; 111(22):8025-30 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
Janus kinases (JAKs) are receptor-associated multidomain tyrosine kinases that act downstream of many cytokines and interferons. JAK kinase activity is regulated by the adjacent pseudokinase domain via an unknown mechanism. Here, we report the 2.8-Å structure of the two-domain pseudokinase-kinase module from the JAK family member TYK2 in its autoinhibited form. We find that the pseudokinase and kinase interact near the kinase active site and that most reported mutations in cancer-associated JAK alleles cluster in or near this interface. Mutation of residues near the TYK2 interface that are analogous to those in cancer-associated JAK alleles, including the V617F and "exon 12" JAK2 mutations, results in increased kinase activity in vitro. These data indicate that JAK pseudokinases are autoinhibitory domains that hold the kinase domain inactive until receptor dimerization stimulates transition to an active state.

Kiel MJ, Velusamy T, Rolland D, et al.
Integrated genomic sequencing reveals mutational landscape of T-cell prolymphocytic leukemia.
Blood. 2014; 124(9):1460-72 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
The comprehensive genetic alterations underlying the pathogenesis of T-cell prolymphocytic leukemia (T-PLL) are unknown. To address this, we performed whole-genome sequencing (WGS), whole-exome sequencing (WES), high-resolution copy-number analysis, and Sanger resequencing of a large cohort of T-PLL. WGS and WES identified novel mutations in recurrently altered genes not previously implicated in T-PLL including EZH2, FBXW10, and CHEK2. Strikingly, WGS and/or WES showed largely mutually exclusive mutations affecting IL2RG, JAK1, JAK3, or STAT5B in 38 of 50 T-PLL genomes (76.0%). Notably, gain-of-function IL2RG mutations are novel and have not been reported in any form of cancer. Further, high-frequency mutations in STAT5B have not been previously reported in T-PLL. Functionally, IL2RG-JAK1-JAK3-STAT5B mutations led to signal transducer and activator of transcription 5 (STAT5) hyperactivation, transformed Ba/F3 cells resulting in cytokine-independent growth, and/or enhanced colony formation in Jurkat T cells. Importantly, primary T-PLL cells exhibited constitutive activation of STAT5, and targeted pharmacologic inhibition of STAT5 with pimozide induced apoptosis in primary T-PLL cells. These results for the first time provide a portrait of the mutational landscape of T-PLL and implicate deregulation of DNA repair and epigenetic modulators as well as high-frequency mutational activation of the IL2RG-JAK1-JAK3-STAT5B axis in the pathogenesis of T-PLL. These findings offer opportunities for novel targeted therapies in this aggressive leukemia.

Ding X, Yang Y, Han B, et al.
Transcriptomic characterization of hepatocellular carcinoma with CTNNB1 mutation.
PLoS One. 2014; 9(5):e95307 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
PURPOSE: Hepatocellular carcinoma (HCC) is the sixth most common solid tumor worldwide and the third leading cause of cancer-related death. HCC is a particularly serious threat to the Chinese population. Although many molecular alterations are known to be involved in the tumorigenesis of hepatocytes, no systemic survey has examined the somatic mutations in HCC samples from Chinese patients. Our goal was to elucidate somatic mutations in Chinese HCC patients and investigate the possible molecular mechanisms involved in tumorigenesis.
EXPERIMENTAL DESIGN: A total of 110 hepatitis B virus (HBV)-positive HCC samples and 46 HBV-negative HCC samples were genotyped for hot-spot mutations in the CSF1R, CTNNB1, KRAS, BRAF, NRAS, ERBB2, MET, PIK3CA, JAK1, and SMO genes. The transcriptomes of the CTNNB1 mutation-positive HCC samples from the HBV-positive patients (CB+ HCC) were compared to adjacent non-cancerous livers, and significantly altered genes were functionally validated in vitro.
RESULTS: CTNNB1 mutations accounted for the majority of the mutations detected in our study. A slightly higher mutation rate was found in the HBV-positive patients than in their negative counterparts. A distinct pattern of CTNNB1 mutation was detected in these two populations, and drastic changes at the transcriptomic level were detected in the CB+ tumors compared to adjacent non-cancerous livers. Potential tumor suppressors (FoxA3 and Onecut1) and oncogenes (MAFG and SSX1) were functionally validated.
CONCLUSIONS: Our work is the first systemic characterization of oncogenic mutations in HCC samples from Chinese patients. Targeting the Wnt-β-catenin pathway may represent a valid treatment option for Chinese HCC patients. Our work also suggests that targeting ONECUT1, FOXA3, SSX1, and MAFG may be a valid treatment option for CTNNB1 mutation positive HCC patients.

Miller CP, Thorpe JD, Kortum AN, et al.
JAK2 expression is associated with tumor-infiltrating lymphocytes and improved breast cancer outcomes: implications for evaluating JAK2 inhibitors.
Cancer Immunol Res. 2014; 2(4):301-6 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
Janus kinase-2 (JAK2) supports breast cancer growth, and clinical trials testing JAK2 inhibitors are under way. In addition to the tumor epithelium, JAK2 is also expressed in other tissues including immune cells; whether the JAK2 mRNA levels in breast tumors correlate with outcomes has not been evaluated. Using a case-control design, JAK2 mRNA was measured in 223 archived breast tumors and associations with distant recurrence were evaluated by logistic regression. The frequency of correct pairwise comparisons of patient rankings based on JAK2 levels versus survival outcomes, the concordance index (CI), was evaluated using data from 2,460 patients in three cohorts. In the case-control study, increased JAK2 was associated with a decreasing risk of recurrence (multivariate P = 0.003, n = 223). Similarly, JAK2 was associated with a protective CI (<0.5) in the public cohorts: NETHERLANDS CI = 0.376, n = 295; METABRIC CI = 0.462, n = 1,981; OSLOVAL CI = 0.452, n = 184. Furthermore, JAK2 was strongly correlated with the favorable prognosis LYM metagene signature for infiltrating T cells (r = 0.5; P < 2 × 10(-16); n = 1,981) and with severe lymphocyte infiltration (P = 0.00003, n = 156). Moreover, the JAK1/2 inhibitor ruxolitinib potently inhibited the anti-CD3-dependent production of IFN-γ, a marker of the differentiation of Th cells along the tumor-inhibitory Th1 pathway. The potential for JAK2 inhibitors to interfere with the antitumor capacities of T cells should be evaluated.

Pilati C, Letouzé E, Nault JC, et al.
Genomic profiling of hepatocellular adenomas reveals recurrent FRK-activating mutations and the mechanisms of malignant transformation.
Cancer Cell. 2014; 25(4):428-41 [PubMed] Related Publications
Hepatocellular adenomas (HCA) are benign liver tumors predominantly developed in women using oral contraceptives. Here, exome sequencing identified recurrent somatic FRK mutations that induce constitutive kinase activity, STAT3 activation, and cell proliferation sensitive to Src inhibitors. We also found uncommon recurrent mutations activating JAK1, gp130, or β-catenin. Chromosome copy number and methylation profiling revealed patterns that correlated with specific gene mutations and tumor phenotypes. Finally, integrative analysis of HCAs transformed to hepatocellular carcinoma revealed β-catenin mutation as an early alteration and TERT promoter mutations as associated with the last step of the adenoma-carcinoma transition. In conclusion, we identified the genomic diversity in benign hepatocyte proliferation, several therapeutic targets, and the key genomic determinants of the adenoma-carcinoma transformation sequence.

Li W, Wei Q, Liang J
Phosphorylated signal transducer and activator of transcription 1 is a potential predictor of interferon response in patients with advanced renal cell carcinoma.
Mol Med Rep. 2014; 9(5):1929-34 [PubMed] Related Publications
The present study aimed to evaluate the expression status of Janus kinase (JAK)-Signal Transducer and Activator of Transcription (STAT) in renal cell carcinoma and benign renal tissue, and identify a potential biomarker for interferon (IFN) response prediction. A total of 32 specimens of human renal cell carcinoma and 10 specimens of benign renal tissue were harvested from surgically removed kidneys. The expression levels of JAK‑STAT were determined by immunohistochemical staining and quantitative polymerase chain reaction. Furthermore, the expression levels of JAK‑STAT in renal cell carcinoma tissues that were stimulated with IFN-α were quantified by western blot analysis. The positive expression rates of JAK1, STAT1 and phosphorylated (P)‑STAT1 in the renal cell carcinomas were significantly lower than that in the benign renal tissues (25.0, 31.2, and 12.5% vs. 70.0, 50.0, and 70.0%, respectively; P<0.05). The relative expression levels of JAK1 (0.696 ± 0.102) and STAT1 mRNA (0.341 ± 0.068) in the tumor tissue were lower than those in the benign tissue (0.957 ± 0.103 and 0.547 ± 0.082, respectively; P<0.05). IFN stimulation enhanced the expression levels of P‑STAT1 in the renal cell carcinoma tissues, and enhancement of the P‑STAT1 expression levels was associated with tumor relapse and metastasis. In conclusion, P‑STAT1 is a potential predictor of IFN response in patients with advanced renal cell carcinoma.

Tanaka T, Arai M, Jiang X, et al.
Downregulation of microRNA-431 by human interferon-β inhibits viability of medulloblastoma and glioblastoma cells via upregulation of SOCS6.
Int J Oncol. 2014; 44(5):1685-90 [PubMed] Related Publications
miRNAs are small non-coding RNAs that inhibit gene expression by cleaving or hindering the translation of target mRNAs. In this study, we focused on miR-431, which mediated inhibition of cell viability by human interferon-β (HuIFN-β). We aimed to demonstrate an antineoplastic effect of HuIFN-β via miR-431 expression against medulloblastoma and glioblastoma, because HuIFN-β is frequently used in adjuvant therapy of these tumors. Addition of HuIFN-β to medulloblastoma and glioblastoma cells reduced viability, significantly decreased miR-431 expression, upregulated expression of SOCS6 (putative miR-431 target genes) and inhibited Janus kinase (JAK) 1 and signal transducer and activator of transcription (STAT) 2. The mitogen-activated protein kinase (MAPK) pathway, but not the phosphoinositide 3-kinase (PI3K)-Akt pathway, was downregulated in medulloblastoma cells, whereas the PI3K-Akt pathway, but not the MAPK pathway, was downregulated in glioblastoma cells. Addition of HuIFN-β and transient transfection with miR-431 to medulloblastoma and glioblastoma cells did not reduce viability, downregulated expression of SOCS6, and concomitantly activated the JAK1 and STAT2. We propose that, in medulloblastoma and glioblastoma cells, HuIFN-β decreases miR-431 expression and upregulates SOCS6 expression, and consequently inhibit cell proliferation by suppressing the JAK-STAT signaling pathway.

Gu L, Talati P, Vogiatzi P, et al.
Pharmacologic suppression of JAK1/2 by JAK1/2 inhibitor AZD1480 potently inhibits IL-6-induced experimental prostate cancer metastases formation.
Mol Cancer Ther. 2014; 13(5):1246-58 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
Metastatic prostate cancer is lethal and lacks effective strategies for prevention or treatment, requiring novel therapeutic approaches. Interleukin-6 (IL-6) is a cytokine that has been linked with prostate cancer pathogenesis by multiple studies. However, the direct functional roles of IL-6 in prostate cancer growth and progression have been unclear. In the present study, we show that IL-6 is produced in distant metastases of clinical prostate cancers. IL-6-activated signaling pathways in prostate cancer cells induced a robust 7-fold increase in metastases formation in nude mice. We further show that IL-6 promoted migratory prostate cancer cell phenotype, including increased prostate cancer cell migration, microtubule reorganization, and heterotypic adhesion of prostate cancer cells to endothelial cells. IL-6-driven metastasis was predominantly mediated by Stat3 and to lesser extent by ERK1/2. Most importantly, pharmacologic inhibition of Jak1/2 by AZD1480 suppressed IL-6-induced signaling, migratory prostate cancer cell phenotypes, and metastatic dissemination of prostate cancer in vivo in nude mice. In conclusion, we demonstrate that the cytokine IL-6 directly promotes prostate cancer metastasis in vitro and in vivo via Jak-Stat3 signaling pathway, and that IL-6-driven metastasis can be effectively suppressed by pharmacologic targeting of Jak1/2 using Jak1/2 inhibitor AZD1480. Our results therefore provide a strong rationale for further development of Jak1/2 inhibitors as therapy for metastatic prostate cancer.

Song CQ, Zhang JH, Shi JC, et al.
Bioinformatic prediction of SNPs within miRNA binding sites of inflammatory genes associated with gastric cancer.
Asian Pac J Cancer Prev. 2014; 15(2):937-43 [PubMed] Related Publications
Polymorphisms in miRNA binding sites have been shown to affect miRNA binding to target genes, resulting in differential mRNA and protein expression and susceptibility to common diseases. Our purpose was to predict SNPs (single nucleotide polymorphisms) within miRNA binding sites of inflammatory genes in relation to gastric cancer. A complete list of SNPs in the 3'UTR regions of all inflammatory genes associated with gastric cancer was obtained from Pubmed. miRNA target prediction databases (MirSNP, Targetscan Human 6.2, PolymiRTS 3.0, miRNASNP 2.0, and Patrocles) were used to predict miRNA target sites. There were 99 SNPs with MAF>0.05 within the miRNA binding sites of 41 genes among 72 inflammation-related genes associated with gastric cancer. NF-κB and JAK-STAT are the two most important signaling pathways. 47 SNPs of 25 genes with 95 miRNAs were predicted. CCL2 and IL1F5 were found to be the shared target genes of hsa-miRNA-624-3p. Bioinformatic methods could identify a set of SNPs within miRNA binding sites of inflammatory genes, and provide data and direction for subsequent functional verification research.

Mathieu MG, Miles AK, Ahmad M, et al.
The helicase HAGE prevents interferon-α-induced PML expression in ABCB5+ malignant melanoma-initiating cells by promoting the expression of SOCS1.
Cell Death Dis. 2014; 5:e1061 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
The tumour suppressor PML (promyelocytic leukaemia protein) regulates several cellular pathways involving cell growth, apoptosis, differentiation and senescence. PML also has an important role in the regulation of stem cell proliferation and differentiation. Here, we show the involvement of the helicase HAGE in the transcriptional repression of PML expression in ABCB5+ malignant melanoma-initiating cells (ABCB5+ MMICs), a population of cancer stem cells which are responsible for melanoma growth, progression and resistance to drug-based therapy. HAGE prevents PML gene expression by inhibiting the activation of the JAK-STAT (janus kinase-signal transducers and activators of transcription) pathway in a mechanism which implicates the suppressor of cytokine signalling 1 (SOCS1). Knockdown of HAGE led to a significant decrease in SOCS1 protein expression, activation of the JAK-STAT signalling cascade and a consequent increase of PML expression. To confirm that the reduction in SOCS1 expression was dependent on the HAGE helicase activity, we showed that SOCS1, effectively silenced by small interfering RNA, could be rescued by re-introduction of HAGE into cells lacking HAGE. Furthermore, we provide a mechanism by which HAGE promotes SOCS1 mRNA unwinding and protein expression in vitro. Finally, using a stem cell proliferation assay and tumour xenotransplantation assay in non-obese diabetic/severe combined immunodeficiency mice, we show that HAGE promotes MMICs-dependent tumour initiation and tumour growth by preventing the anti-proliferative effects of interferon-α (IFNα). Our results suggest that the helicase HAGE has a key role in the resistance of ABCB5+ MMICs to IFNα treatment and that cancer therapies targeting HAGE may have broad implications for the treatment of malignant melanoma.

Zhang Q, Wang HY, Wei F, et al.
Cutaneous T cell lymphoma expresses immunosuppressive CD80 (B7-1) cell surface protein in a STAT5-dependent manner.
J Immunol. 2014; 192(6):2913-9 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
In this article, we report that cutaneous T cell lymphoma (CTCL) cells and tissues ubiquitously express the immunosuppressive cell surface protein CD80 (B7-1). CD80 expression in CTCL cells is strictly dependent on the expression of both members of the STAT5 family, STAT5a and STAT5b, as well as their joint ability to transcriptionally activate the CD80 gene. In IL-2-dependent CTCL cells, CD80 expression is induced by the cytokine in a Jak1/3- and STAT5a/b-dependent manner, whereas in the CTCL cells with constitutive STAT5 activation, CD80 expression is also STAT5a/b dependent but is independent of Jak activity. Although depletion of CD80 expression does not affect the proliferation rate and viability of CTCL cells, induced expression of the cell-inhibitory receptor of CD80, CD152 (CTLA-4), impairs growth of the cells. Coculture of CTCL cells with normal T lymphocytes consisting of both CD4(+) and CD8(+) populations or the CD4(+) subset alone, transfected with CD152 mRNA, inhibits proliferation of normal T cells in a CD152- and CD80-dependent manner. These data identify a new mechanism of immune evasion in CTCL and suggest that the CD80-CD152 axis may become a therapeutic target in this type of lymphoma.

Nam D, Song J, Kim SM, et al.
8-hydrocalamenene, derived from Reynoutria elliptica, suppresses constitutive STAT3 activation, inhibiting proliferation and enhancing chemosensitization of human multiple myeloma cells.
J Med Food. 2014; 17(3):365-73 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
The identification of the active compounds of herbal medicines and the molecular targets of those compounds is an attractive therapeutic objective. Reynoutria elliptica has been used for the treatment of various inflammatory diseases as a Korean folk remedy. Based on the evidence that anti-inflammatory agents frequently exert antiproliferative activity, we tested two sesquiterpene derivatives, 8-hydrocalamenene (HC) and 8,14-dihydrocalamenene (DHC), for their ability to induce apoptosis and suppress signal transducer and activator of transcription 3 (STAT3) activation in multiple myeloma (MM) U266 cells. We found that HC inhibited cell viability in U266, but not in peripheral blood mononuclear cells. HC exerted significant cytotoxicity and induced substantial subG1-phase arrest and apoptosis as compared with DHC. HC inhibited the expression of gene products involved in antiapoptosis (Bcl-2 and Bcl-xL), proliferation (cyclin D1), and invasion (MMP-9), all of which are known to be regulated by STAT3. Furthermore, HC up-regulated cyclin-dependent kinase inhibitor p21 and induced apoptosis through the activation of caspase-8, -9, and -3 in U266 cells. Interestingly, HC blocked constitutive STAT3 activation through the inhibition of activation of upstream kinases Janus-like kinase 1 (JAK1), JAK2, and c-Src and up-regulated PIAS3. Deletion of STAT3 reversed cytotoxic effects and the down-regulation of cyclin D1 and c-myc by HC in MM cells. Finally, this sesquiterpene significantly synergized the cytotoxic and apoptotic effects of bortezomib in U266 cells. Taken together, these results suggest that HC is a novel blocker of STAT3 activation which may have a potential in the prevention and treatment of MM.

Pratt J, Annabi B
Induction of autophagy biomarker BNIP3 requires a JAK2/STAT3 and MT1-MMP signaling interplay in Concanavalin-A-activated U87 glioblastoma cells.
Cell Signal. 2014; 26(5):917-24 [PubMed] Related Publications
Plant lectins have been considered as possible anti-tumor drugs because of their property to induce autophagic cell death. Given that expression of membrane type-1 matrix metalloproteinase (MT1-MMP) has been found to regulate expression of the autophagy biomarker Bcl-2/adenovirus E1B 19kDa interacting protein 3 (BNIP3), we sought to investigate possible signaling interplay mechanisms between MT1-MMP and BNIP3 in Concanavalin-A (ConA) lectin-activated U87 glioblastoma cells. ConA induced acidic vacuole organelle formation as well as BNIP3 and MT1-MMP gene and protein expressions, whereas only BNIP3 expression was dose-dependently inhibited by the JAK2 tyrosine kinase inhibitor AG490 suggesting a requirement for some STAT-mediated signaling. Gene silencing of MT1-MMP and of STAT3 abrogated ConA-induced STAT3 phosphorylation and BNIP3 expression. Correlative analysis shows that STAT3 signaling events occur downstream from MT1-MMP induction. Overexpression of a full length MT1-MMP recombinant protein led to increased BNIP3 gene and protein expressions. The cytoplasmic domain of MT1-MMP was also found necessary for transducing STAT3 phosphorylation. Among JAK1, JAK2, JAK3, and TYK2, only JAK2 gene silencing abrogated ConA's effects on MT1-MMP and BNIP3 gene and protein expressions. Our study elucidates how MT1-MMP signals autophagy, a process which could contribute to the chemoresistance phenotype in brain cancer cells.

Stuart E, Buchert M, Putoczki T, et al.
Therapeutic inhibition of Jak activity inhibits progression of gastrointestinal tumors in mice.
Mol Cancer Ther. 2014; 13(2):468-74 [PubMed] Related Publications
Aberrant activation of the latent transcription factor STAT3 and its downstream targets is a common feature of epithelial-derived human cancers, including those of the gastrointestinal tract. Mouse models of gastrointestinal malignancy implicate Stat3 as a key mediator of inflammatory-driven tumorigenesis, in which its cytokine/gp130/Janus kinase (Jak)-dependent activation provides a functional link through which the microenvironment sustains tumor promotion. Although therapeutic targeting of STAT3 is highly desirable, such molecules are not available for immediate clinical assessment. Here, we investigated whether the small-molecule Jak1/2 inhibitor AZD1480 confers therapeutic benefits in two mouse models of inflammation-associated gastrointestinal cancer, which are strictly dependent of excessive Stat3 activation. We confirm genetically that Cre-mediated, tumor cell-specific reduction of Stat3 expression arrests the growth of intestinal-type gastric tumors in gp130(F/F) mice. We find that systemic administration of AZD1480 readily replicates this effect, which is associated with reduced Stat3 activation and correlates with diminished tumor cell proliferation and increased apoptosis. Likewise, AZD1480 therapy also conferred a cytostatic effect on established tumors in a colitis-associated colon cancer model in wild-type mice. As predicted from our genetic observations in gp130(F/F) mice, the therapeutic effect of AZD1480 remains fully reversible upon cessation of compound administration. Collectively, our results provide the first evidence that pharmacologic targeting of excessively activated wild-type Jak kinases affords therapeutic suppression of inflammation-associated gastrointestinal cancers progression in vivo.

Gu DL, Chen YH, Shih JH, et al.
Target genes discovery through copy number alteration analysis in human hepatocellular carcinoma.
World J Gastroenterol. 2013; 19(47):8873-9 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
High-throughput short-read sequencing of exomes and whole cancer genomes in multiple human hepatocellular carcinoma (HCC) cohorts confirmed previously identified frequently mutated somatic genes, such as TP53, CTNNB1 and AXIN1, and identified several novel genes with moderate mutation frequencies, including ARID1A, ARID2, MLL, MLL2, MLL3, MLL4, IRF2, ATM, CDKN2A, FGF19, PIK3CA, RPS6KA3, JAK1, KEAP1, NFE2L2, C16orf62, LEPR, RAC2, and IL6ST. Functional classification of these mutated genes suggested that alterations in pathways participating in chromatin remodeling, Wnt/β-catenin signaling, JAK/STAT signaling, and oxidative stress play critical roles in HCC tumorigenesis. Nevertheless, because there are few druggable genes used in HCC therapy, the identification of new therapeutic targets through integrated genomic approaches remains an important task. Because a large amount of HCC genomic data genotyped by high density single nucleotide polymorphism arrays is deposited in the public domain, copy number alteration (CNA) analyses of these arrays is a cost-effective way to reveal target genes through profiling of recurrent and overlapping amplicons, homozygous deletions and potentially unbalanced chromosomal translocations accumulated during HCC progression. Moreover, integration of CNAs with other high-throughput genomic data, such as aberrantly coding transcriptomes and non-coding gene expression in human HCC tissues and rodent HCC models, provides lines of evidence that can be used to facilitate the identification of novel HCC target genes with the potential of improving the survival of HCC patients.

Lee JH, Chiang SY, Nam D, et al.
Capillarisin inhibits constitutive and inducible STAT3 activation through induction of SHP-1 and SHP-2 tyrosine phosphatases.
Cancer Lett. 2014; 345(1):140-8 [PubMed] Related Publications
Signal transducers and activators of transcription (STAT)-3 is a latent cytosolic transcription factor that has been closely associated with survival, proliferation, chemoresistance, and metastasis of tumor cells. Whether the anti-proliferative, pro-apoptotic, and anti-metastatic effects of capillarisin (CPS), derived from Artemisia capillaris (Compositae), are linked to its capability to inhibit STAT3 activation was investigated. We found that CPS specifically inhibited both constitutive and inducible STAT3 activation at tyrosine residue 705 but not at serine residue 727 in human multiple myeloma cells. Besides the inhibition of STAT3 phosphorylation, CPS also abrogated STAT3 constitutive activity and nuclear translocation. The suppression of STAT3 was mediated through the inhibition of activation of upstream JAK1, JAK2, and c-Src kinases. Treatment with the protein tyrosine phosphatase (PTP) inhibitor pervanadate treatment reversed the CPS-induced down-regulation of JAK1/2 and STAT3, thereby suggesting the involvement of a PTP. Indeed, knockdown of the SHP-1 and SHP-2 genes by small interfering RNA suppressed the ability of CPS to inhibit JAK1 and STAT3 activation, suggesting the critical role of both SHP-1 and SHP-2 in its possible mechanism of action. CPS downregulated the expression of STAT3-regulated antiapoptotic and proliferative gene products; and this correlated with suppression of cell viability, the accumulation of cells in sub-G1 phase of cell cycle and induction of apoptosis. Moreover, CPS potentiated bortezomib-induced apoptotic effects in MM cells, and this correlated with down-regulation of various gene products that mediate cell proliferation (Cyclin D1 and COX-2), cell survival (Bcl-2, Bcl-xl, IAP1, IAP2, and Survivin), invasion (MMP-9), and angiogenesis (VEGF). Thus, overall, our results suggest that CPS is a novel blocker of STAT3 activation and thus may have a potential in negative regulation of growth, metastasis, and chemoresistance of tumor cells.

Jiao Y, Yonescu R, Offerhaus GJ, et al.
Whole-exome sequencing of pancreatic neoplasms with acinar differentiation.
J Pathol. 2014; 232(4):428-35 [PubMed] Article available free on PMC after 23/09/2015 Related Publications
Pancreatic carcinomas with acinar differentiation, including acinar cell carcinoma, pancreatoblastoma and carcinomas with mixed differentiation, are distinct pancreatic neoplasms with poor prognosis. Although recent whole-exome sequencing analyses have defined the somatic mutations that characterize the other major neoplasms of the pancreas, the molecular alterations underlying pancreatic carcinomas with acinar differentiation remain largely unknown. In the current study, we sequenced the exomes of 23 surgically resected pancreatic carcinomas with acinar differentiation. These analyses revealed a relatively large number of genetic alterations at both the individual base pair and chromosomal levels. There was an average of 119 somatic mutations/carcinoma. When three outliers were excluded, there was an average of 64 somatic mutations/tumour (range 12-189). The mean fractional allelic loss (FAL) was 0.27 (range 0-0.89) and heterogeneity at the chromosome level was confirmed in selected cases using fluorescence in situ hybridization (FISH). No gene was mutated in >30% of the cancers. Genes altered in other neoplasms of the pancreas were occasionally targeted in carcinomas with acinar differentiation; SMAD4 was mutated in six tumours (26%), TP53 in three (13%), GNAS in two (9%), RNF43 in one (4%) and MEN1 in one (4%). Somatic mutations were identified in genes in which constitutional alterations are associated with familial pancreatic ductal adenocarcinoma, such as ATM, BRCA2 and PALB2 (one tumour each), as well as in genes altered in extra-pancreatic neoplasms, such as JAK1 in four tumours (17%), BRAF in three (13%), RB1 in three (13%), APC in two (9%), PTEN in two (9%), ARID1A in two (9%), MLL3 in two (9%) and BAP1 in one (4%). Perhaps most importantly, we found that more than one-third of these carcinomas have potentially targetable genetic alterations, including mutations in BRCA2, PALB2, ATM, BAP1, BRAF and JAK1.

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Cite this page: Cotterill SJ. JAK1 gene, Cancer Genetics Web: http://www.cancer-genetics.org/JAK1.htm Accessed:

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