IL7R

Gene Summary

Gene:IL7R; interleukin 7 receptor
Aliases: ILRA, CD127, IL7RA, CDW127, IL-7R-alpha
Location:5p13.2
Summary:The protein encoded by this gene is a receptor for interleukin 7 (IL7). The function of this receptor requires the interleukin 2 receptor, gamma chain (IL2RG), which is a common gamma chain shared by the receptors of various cytokines, including interleukins 2, 4, 7, 9, and 15. This protein has been shown to play a critical role in V(D)J recombination during lymphocyte development. Defects in this gene may be associated with severe combined immunodeficiency (SCID). Alternatively spliced transcript variants have been found. [provided by RefSeq, Dec 2015]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:interleukin-7 receptor subunit alpha
Source:NCBIAccessed: 16 March, 2017

Ontology:

What does this gene/protein do?
Show (25)
Pathways:What pathways are this gene/protein implicaed in?
Show (4)

Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 16 March 2017 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.

  • Genetic Predisposition
  • Janus Kinases
  • Risk Factors
  • Mutation
  • Transcription
  • Receptors, Cytokine
  • Oligonucleotide Array Sequence Analysis
  • NOTCH1 Receptor
  • RTPCR
  • Protein Kinase Inhibitors
  • Acute Lymphocytic Leukaemia
  • Th1 Cells
  • Molecular Sequence Data
  • Cancer Gene Expression Regulation
  • Homeodomain Proteins
  • DNA Mutational Analysis
  • Childhood Cancer
  • Case-Control Studies
  • T-Lymphocytes
  • Base Sequence
  • Acute Myeloid Leukaemia
  • Mice, Inbred NOD
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma
  • Smoking
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma
  • Single Nucleotide Polymorphism
  • Gene Expression
  • Cell Line
  • Receptors, Interleukin-7
  • Apoptosis
  • Biomarkers, Tumor
  • Leukemic Gene Expression Regulation
  • Adolescents
  • Flow Cytometry
  • Translocation
  • fms-Like Tyrosine Kinase 3
  • Gene Expression Profiling
  • Infant
  • Chromosome 5
  • Signal Transduction
Tag cloud generated 16 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (3)

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: IL7R (cancer-related)

Cheng Y, Chikwava K, Wu C, et al.
LNK/SH2B3 regulates IL-7 receptor signaling in normal and malignant B-progenitors.
J Clin Invest. 2016; 126(4):1267-81 [PubMed] Free Access to Full Article Related Publications
Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a high-risk ALL commonly associated with alterations that affect the tyrosine kinase pathway, tumor suppressors, and lymphoid transcription factors. Loss-of-function mutations in the gene-encoding adaptor protein LNK (also known as SH2B3) are found in Ph-like ALLs; however, it is not clear how LNK regulates normal B cell development or promotes leukemogenesis. Here, we have shown that combined loss of Lnk and tumor suppressors Tp53 or Ink4a/Arf in mice triggers a highly aggressive and transplantable precursor B-ALL. Tp53-/-Lnk-/- B-ALLs displayed similar gene expression profiles to human Ph-like B-ALLs, supporting use of this model for preclinical and molecular studies. Preleukemic Tp53-/-Lnk-/- pro-B progenitors were hypersensitive to IL-7, exhibited marked self-renewal in vitro and in vivo, and were able to initiate B-ALL in transplant recipients. Mechanistically, we demonstrated that LNK regulates pro-B progenitor homeostasis by attenuating IL-7-stimuated JAK/STAT5 signaling via a direct interaction with phosphorylated JAK3. Moreover, JAK inhibitors were effective in prolonging survival of mice transplanted with Lnk-/-Tp53-/- leukemia. Additionally, synergistic administration of PI3K/mTOR and JAK inhibitors further abrogated leukemia development. Hence, our results suggest that LNK suppresses IL-7R/JAK/STAT signaling to restrict pro-/pre-B progenitor expansion and leukemia development, providing a pathogenic mechanism and a potential therapeutic approach for B-ALLs with LNK mutations.

Noronha EP, Andrade FG, Zampier C, et al.
Immunophenotyping with CD135 and CD117 predicts the FLT3, IL-7R and TLX3 gene mutations in childhood T-cell acute leukemia.
Blood Cells Mol Dis. 2016; 57:74-80 [PubMed] Related Publications
With the combination of immunophenotyping and molecular tests, it is still a challenge to identify the characteristics of T cell acute lymphoblastic leukemia (T-ALL) associated with distinct outcomes. This study tests the possible correlation of cellular expression of CD135 and CD117 with somatic gene mutations in T-ALL. One hundred sixty-two samples were tested, including 143 at diagnosis, 15 from T-lymphoblastic lymphoma at relapse, and four relapse samples from sequential follow-up of T-ALL. CD135 and CD117 monoclonal antibodies were included in the T-ALL panel of flow cytometry. The percentage of cells positivity and the median fluorescence intensity were correlated with gene mutational status. STIL-TAL1, TLX3, FLT3 and IL7R mutations were tested using standard techniques. STIL-TAL1 was found in 24.8%, TLX3 in 12%, IL7R in 10% and FLT3-ITD in 5% of cases. FLT3 and IL7R mutations were mutually exclusive, as were FLT3-ITD and STIL-TAL1. Associations of CD135(high) (p<0.01), CD117(intermediate/high) (p=0.02) and FLT3-ITD, CD117(low) with IL7R(mutated) (p<0.01) and CD135(high) with TLX3(pos) were observed. We conclude that the addition of CD135 and CD117 to the diagnosis can predict molecular aberrations in T-ALL settings, mainly segregating patients with FLT3-ITD, who would benefit from treatment with inhibitors of tyrosine.

Willerslev-Olsen A, Krejsgaard T, Lindahl LM, et al.
Staphylococcal enterotoxin A (SEA) stimulates STAT3 activation and IL-17 expression in cutaneous T-cell lymphoma.
Blood. 2016; 127(10):1287-96 [PubMed] Free Access to Full Article Related Publications
Cutaneous T-cell lymphoma (CTCL) is characterized by proliferation of malignant T cells in a chronic inflammatory environment. With disease progression, bacteria colonize the compromised skin barrier and half of CTCL patients die of infection rather than from direct organ involvement by the malignancy. Clinical data indicate that bacteria play a direct role in disease progression, but little is known about the mechanisms involved. Here, we demonstrate that bacterial isolates containing staphylococcal enterotoxin A (SEA) from the affected skin of CTCL patients, as well as recombinant SEA, stimulate activation of signal transducer and activator of transcription 3 (STAT3) and upregulation of interleukin (IL)-17 in immortalized and primary patient-derived malignant and nonmalignant T cells. Importantly, SEA induces STAT3 activation and IL-17 expression in malignant T cells when cocultured with nonmalignant T cells, indicating an indirect mode of action. In accordance, malignant T cells expressing an SEA-nonresponsive T-cell receptor variable region β chain are nonresponsive to SEA in monoculture but display strong STAT3 activation and IL-17 expression in cocultures with SEA-responsive nonmalignant T cells. The response is induced via IL-2 receptor common γ chain cytokines and a Janus kinase 3 (JAK3)-dependent pathway in malignant T cells, and blocked by tofacitinib, a clinical-grade JAK3 inhibitor. In conclusion, we demonstrate that SEA induces cell cross talk-dependent activation of STAT3 and expression of IL-17 in malignant T cells, suggesting a mechanism whereby SEA-producing bacteria promote activation of an established oncogenic pathway previously implicated in carcinogenesis.

Bołkun Ł, Rusak M, Eljaszewicz A, et al.
Enhanced pretreatment CD25 expression on peripheral blood CD4+ T cell predicts shortened survival in acute myeloid leukemia patients receiving induction chemotherapy.
Pharmacol Rep. 2016; 68(1):12-9 [PubMed] Related Publications
BACKGROUND: Recently, identification of CD25 (interleukin-2 receptor alpha) expression on leukemic blasts was correlated to early treatment failure and unfavorable outcome in acute myeloid leukemia (AML) patients. Here we wished to determine whether quantification of CD25 on peripheral blood CD4+ T cells could improve prognostication in newly diagnosed AML patients.
METHODS: The mean fluorescence intensity (MFI) of CD25 expression and frequencies of peripheral blood CD4+ T cells with varying levels of CD25 and CD127 expression were assessed by flow cytometry in all studied individuals.
RESULTS: Using univariate (unadjusted) and multivariate (adjusted) analyses we demonstrated that detection of high pretreatment CD25 expression on circulating CD4+ T cells was associated with significantly decreased survival rate of AML patients subjected to standard induction chemotherapy. These associations held true for both entire group of analyzed AML patients and different subgroups of patients identified by presence or absence of favorable and adverse molecular prognostic factors.
CONCLUSIONS: Our data indicate that quantification of CD25 expression on peripheral blood CD4+ T cells could become a novel, easily accessible method of shortened survival prognostication of AML patients subjected to standard cytotoxic therapy.

Hopkins TG, Mura M, Al-Ashtal HA, et al.
The RNA-binding protein LARP1 is a post-transcriptional regulator of survival and tumorigenesis in ovarian cancer.
Nucleic Acids Res. 2016; 44(3):1227-46 [PubMed] Free Access to Full Article Related Publications
RNA-binding proteins (RBPs) are increasingly identified as post-transcriptional drivers of cancer progression. The RBP LARP1 is an mRNA stability regulator, and elevated expression of the protein in hepatocellular and lung cancers is correlated with adverse prognosis. LARP1 associates with an mRNA interactome that is enriched for oncogenic transcripts. Here we explore the role of LARP1 in epithelial ovarian cancer, a disease characterized by the rapid acquisition of resistance to chemotherapy through the induction of pro-survival signalling. We show, using ovarian cell lines and xenografts, that LARP1 is required for cancer cell survival and chemotherapy resistance. LARP1 promotes tumour formation in vivo and maintains cancer stem cell-like populations. Using transcriptomic analysis following LARP1 knockdown, cross-referenced against the LARP1 interactome, we identify BCL2 and BIK as LARP1 mRNA targets. We demonstrate that, through an interaction with the 3' untranslated regions (3' UTRs) of BCL2 and BIK, LARP1 stabilizes BCL2 but destabilizes BIK with the net effect of resisting apoptosis. Together, our data indicate that by differentially regulating the stability of a selection of mRNAs, LARP1 promotes ovarian cancer progression and chemotherapy resistance.

Valletta S, Dolatshad H, Bartenstein M, et al.
ASXL1 mutation correction by CRISPR/Cas9 restores gene function in leukemia cells and increases survival in mouse xenografts.
Oncotarget. 2015; 6(42):44061-71 [PubMed] Free Access to Full Article Related Publications
Recurrent somatic mutations of the epigenetic modifier and tumor suppressor ASXL1 are common in myeloid malignancies, including chronic myeloid leukemia (CML), and are associated with poor clinical outcome. CRISPR/Cas9 has recently emerged as a powerful and versatile genome editing tool for genome engineering in various species. We have used the CRISPR/Cas9 system to correct the ASXL1 homozygous nonsense mutation present in the CML cell line KBM5, which lacks ASXL1 protein expression. CRISPR/Cas9-mediated ASXL1 homozygous correction resulted in protein re-expression with restored normal function, including down-regulation of Polycomb repressive complex 2 target genes. Significantly reduced cell growth and increased myeloid differentiation were observed in ASXL1 mutation-corrected cells, providing new insights into the role of ASXL1 in human myeloid cell differentiation. Mice xenografted with mutation-corrected KBM5 cells showed significantly longer survival than uncorrected xenografts. These results show that the sole correction of a driver mutation in leukemia cells increases survival in vivo in mice. This study provides proof-of-concept for driver gene mutation correction via CRISPR/Cas9 technology in human leukemia cells and presents a strategy to illuminate the impact of oncogenic mutations on cellular function and survival.

Pham LV, Lu G, Tamayo AT, et al.
Establishment and characterization of a novel MYC/BCL2 "double-hit" diffuse large B cell lymphoma cell line, RC.
J Hematol Oncol. 2015; 8:121 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Diffuse large B cell lymphoma (DLBCL) is the most common type of lymphoid malignancy worldwide. Approximately 5 % of cases of DLBCL are so-called double-hit lymphomas (DHL), defined by a chromosomal translocation or rearrangement involving MYC/8q24.2 in combination with another recurrent breakpoint, usually BCL2/18q21.3. Patients with MYC/BCL2 DHL are resistant to standard front-line therapy, and currently, there is no consensus for a therapeutic strategy to treat these patients. Lack of clinically relevant or validated human experimental DHL models of any type that would improve our understanding of the biologic basis of MYC/BCL2 DHL pathophysiology continues to hamper identification of valid therapeutic targets. We describe a unique MYC/BCL2 DHL cell line with morphologic features of DLBCL that we have established, designated as RC.
METHODS: We used tissue culture techniques to establish the RC cell line from primary DLBCL cells. We also utilized molecular and cellular biological techniques including flow cytometry, polymerase chain reaction (PCR), DNA fingerprinting, reverse-phase protein array, conventional cytogenetics, and fluorescence in situ hybridization (FISH) analysis to characterize the RC cell line. NSG-severe combined immunodeficiency (SCID) mice were utilized as a model for xeno-transplantation of RC cells.
RESULTS: RC cells had the following immunophenotype: positive for CD10, CD19, CD20, CD22, CD38, CD43, CD44, and CD79b and negative for CD3, CD4, CD5, CD8, CD11c, CD14, CD30, CD56, and CD200, which was identical to the primary tumor cells. Conventional cytogenetic analysis showed a t(2;8)(p12;q24.2) and t(14;18)(q32;q21.3), corresponding to MYC and BCL2 gene rearrangements, respectively. DNA fingerprinting authenticated the RC cell line to be of the same clone as the primary tumor cells. In addition, RC cells were established in SCID mice as an in vivo model for translational therapeutics studies. Proteomic analysis showed activation of the mTOR signaling pathway in RC cells that can be targeted with an mTOR inhibitor.
CONCLUSION: The data presented confirm the validity of the RC cell line as a representative model of MYC/BCL2 DHL that will be useful for both in vitro and in vivo studies of DHL pathogenesis and therapeutics.

Sharma N, Nanta R, Sharma J, et al.
PI3K/AKT/mTOR and sonic hedgehog pathways cooperate together to inhibit human pancreatic cancer stem cell characteristics and tumor growth.
Oncotarget. 2015; 6(31):32039-60 [PubMed] Free Access to Full Article Related Publications
Cancer stem cells (CSCs) play major roles in cancer initiation, progression, and metastasis. It is evident from growing reports that PI3K/Akt/mTOR and Sonic Hedgehog (Shh) signaling pathways are aberrantly reactivated in pancreatic CSCs. Here, we examined the efficacy of combining NVP-LDE-225 (PI3K/mTOR inhibitor) and NVP-BEZ-235 (Smoothened inhibitor) on pancreatic CSCs characteristics, microRNA regulatory network, and tumor growth. NVP-LDE-225 co-operated with NVP-BEZ-235 in inhibiting pancreatic CSC's characteristics and tumor growth in mice by acting at the level of Gli. Combination of NVP-LDE-225 and NVP-BEZ-235 inhibited self-renewal capacity of CSCs by suppressing the expression of pluripotency maintaining factors Nanog, Oct-4, Sox-2 and c-Myc, and transcription of Gli. NVP-LDE-225 co-operated with NVP-BEZ-235 to inhibit Lin28/Let7a/Kras axis in pancreatic CSCs. Furthermore, a superior interaction of these drugs was observed on spheroid formation by pancreatic CSCs isolated from Pankras/p53 mice. The combination of these drugs also showed superior effects on the expression of proteins involved in cell proliferation, survival and apoptosis. In addition, NVP-LDE-225 co-operated with NVP-BEZ-235 in inhibiting EMT through modulation of cadherin, vimentin and transcription factors Snail, Slug and Zeb1. In conclusion, these data suggest that the combined inhibition of PI3K/Akt/mTOR and Shh pathways may be beneficial for the treatment of pancreatic cancer.

Kuramitsu S, Ohno M, Ohka F, et al.
Lenalidomide enhances the function of chimeric antigen receptor T cells against the epidermal growth factor receptor variant III by enhancing immune synapses.
Cancer Gene Ther. 2015; 22(10):487-95 [PubMed] Related Publications
The epidermal growth factor receptor variant III (EGFRvIII) is exclusively expressed on the cell surface in ~50% of glioblastoma multiforme (GBM). This variant strongly and persistently activates the phosphatidylinositol 3-kinase-Akt signaling pathway in a ligand-independent manner resulting in enhanced tumorigenicity, cellular motility and resistance to chemoradiotherapy. Our group generated a recombinant single-chain variable fragment (scFv) antibody specific to the EGFRvIII, referred to as 3C10-scFv. In the current study, we constructed a lentiviral vector transducing the chimeric antigen receptor (CAR) that consisted of 3C10-scFv, CD3ζ, CD28 and 4-1BB (3C10-CAR). The 3C10-CAR-transduced peripheral blood mononuclear cells (PBMCs) and CD3(+) T cells specifically lysed the glioma cells that express EGFRvIII. Moreover, we demonstrated that CAR CD3(+) T cells migrated to the intracranial xenograft of GBM in the mice treated with 3C10-CAR PBMCs. An important and novel finding of our study was that a thalidomide derivative lenalidomide induced 3C10-CAR PBMC proliferation and enhanced the persistent antitumor effect of the cells in vivo. Lenalidomide also exhibited enhanced immunological synapses between the effector cells and the target cells as determined by CD11a and F-actin polymerization. Collectively, lentiviral-mediated transduction of CAR effectors targeting the EGFRvIII showed specific efficacy, and lenalidomide even intensified CAR cell therapy by enhanced formation of immunological synapses.

Park H, Cho SY, Kim H, et al.
Genomic alterations in BCL2L1 and DLC1 contribute to drug sensitivity in gastric cancer.
Proc Natl Acad Sci U S A. 2015; 112(40):12492-7 [PubMed] Free Access to Full Article Related Publications
Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. Recent high-throughput analyses of genomic alterations revealed several driver genes and altered pathways in GC. However, therapeutic applications from genomic data are limited, largely as a result of the lack of druggable molecular targets and preclinical models for drug selection. To identify new therapeutic targets for GC, we performed array comparative genomic hybridization (aCGH) of DNA from 103 patients with GC for copy number alteration (CNA) analysis, and whole-exome sequencing from 55 GCs from the same patients for mutation profiling. Pathway analysis showed recurrent alterations in the Wnt signaling [APC, CTNNB1, and DLC1 (deleted in liver cancer 1)], ErbB signaling (ERBB2, PIK3CA, and KRAS), and p53 signaling/apoptosis [TP53 and BCL2L1 (BCL2-like 1)] pathways. In 18.4% of GC cases (19/103), amplification of the antiapoptotic gene BCL2L1 was observed, and subsequently a BCL2L1 inhibitor was shown to markedly decrease cell viability in BCL2L1-amplified cell lines and in similarly altered patient-derived GC xenografts, especially when combined with other chemotherapeutic agents. In 10.9% of cases (6/55), mutations in DLC1 were found and were also shown to confer a growth advantage for these cells via activation of Rho-ROCK signaling, rendering these cells more susceptible to a ROCK inhibitor. Taken together, our study implicates BCL2L1 and DLC1 as potential druggable targets for specific subsets of GC cases.

Zhang M, Mathews Griner LA, Ju W, et al.
Selective targeting of JAK/STAT signaling is potentiated by Bcl-xL blockade in IL-2-dependent adult T-cell leukemia.
Proc Natl Acad Sci U S A. 2015; 112(40):12480-5 [PubMed] Free Access to Full Article Related Publications
Adult T-cell leukemia (ATL) develops in individuals infected with human T-cell lymphotropic virus-1 (HTLV-1). Presently there is no curative therapy for ATL. HTLV-1-encoded protein Tax (transactivator from the X-gene region) up-regulates Bcl-xL (B-cell lymphoma-extra large) expression and activates interleukin-2 (IL-2), IL-9, and IL-15 autocrine/paracrine systems, resulting in amplified JAK/STAT signaling. Inhibition of JAK signaling reduces cytokine-dependent ex vivo proliferation of peripheral blood mononuclear cells (PBMCs) from ATL patients in smoldering/chronic stages. Currently, two JAK inhibitors are approved for human use. In this study, we examined activity of multiple JAK inhibitors in ATL cell lines. The selective JAK inhibitor ruxolitinib was examined in a high-throughput matrix screen combined with >450 potential therapeutic agents, and Bcl-2/Bcl-xL inhibitor navitoclax was identified as a strong candidate for multicomponent therapy. The combination was noted to strongly activate BAX (Bcl-2-associated X protein), effect mitochondrial depolarization, and increase caspase 3/7 activities that lead to cleavage of PARP (poly ADP ribose polymerase) and Mcl-1 (myeloid cell leukemia 1). Ruxolitinib and navitoclax independently demonstrated modest antitumor efficacy, whereas the combination dramatically lowered tumor burden and prolonged survival in an ATL murine model. This combination strongly blocked ex vivo proliferation of five ATL patients' PBMCs. These studies provide support for a therapeutic trial in patients with smoldering/chronic ATL using a drug combination that inhibits JAK signaling and antiapoptotic protein Bcl-xL.

Yuan L, Lu L, Yang Y, et al.
Genetic mutational profiling analysis of T cell acute lymphoblastic leukemia reveal mutant FBXW7 as a prognostic indicator for inferior survival.
Ann Hematol. 2015; 94(11):1817-28 [PubMed] Related Publications
T cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplasm for which there are currently no adequate biomarkers for developing risk-adapted therapeutic regimens to improve the treatment outcome. In this prospective study of 83 Chinese patients (54 children and 29 adults) with de novo T-ALL, we analyzed mutations in 11 T-ALL genes: NOTCH1, FBXW7, PHF6, PTEN, N-RAS, K-RAS, WT1, IL7R, PIK3CA, PIK3RA, and AKT1. NOTCH1 mutations were identified in 51.9 and 37.9 % of pediatric and adult patients, respectively, and these patients showed improved overall survival (OS) and event-free survival (EFS). The FBXW7 mutant was present in 25.9 and 6.9 % of pediatric and adult patients, respectively, and was associated with inferior OS and EFS in pediatric T-ALL. Multivariate analysis revealed that mutant FBXW7 was an independent prognostic indicator for inferior EFS (hazard ratio [HR] 4.38; 95 % confidence interval [CI] 1.15-16.71; p = 0.03) and tended to be associated with reduced OS (HR 2.81; 95 % CI 0.91-8.69; p = 0.074) in pediatric T-ALL. Mutant PHF6 was present in 13 and 20.7 % of our childhood and adult cohorts, respectively, while PTEN mutations were noted in 11.1 % of the pediatric patients. PTEN and NOTCH1 mutations were almost mutually exclusive, while IL7R and WT1 mutations were rare in pediatric T-ALL and PTPN11 and AKT1 mutations were infrequent in adult T-ALL. This study revealed differences in the mutational profiles of pediatric and adult T-ALL and suggests mutant FBXW7 as an independent prognostic indicator for inferior survival in pediatric T-ALL.

Ramsdale R, Jorissen RN, Li FZ, et al.
The transcription cofactor c-JUN mediates phenotype switching and BRAF inhibitor resistance in melanoma.
Sci Signal. 2015; 8(390):ra82 [PubMed] Related Publications
Most patients with BRAF-mutant metastatic melanoma display remarkable but incomplete and short-lived responses to inhibitors of the BRAF kinase or the mitogen-activated protein kinase kinase (MEK), collectively BRAF/MEK inhibitors. We found that inherent resistance to these agents in BRAF(V600)-mutant melanoma cell lines was associated with high abundance of c-JUN and characteristics of a mesenchymal-like phenotype. Early drug adaptation in drug-sensitive cell lines grown in culture or as xenografts, and in patient samples during therapy, was consistently characterized by down-regulation of SPROUTY4 (a negative feedback regulator of receptor tyrosine kinases and the BRAF-MEK signaling pathway), increased expression of JUN and reduced expression of LEF1. This coincided with a switch in phenotype that resembled an epithelial-mesenchymal transition (EMT). In cultured cells, these BRAF inhibitor-induced changes were reversed upon removal of the drug. Knockdown of SPROUTY4 was sufficient to increase the abundance of c-JUN in the absence of drug treatment. Overexpressing c-JUN in drug-naïve melanoma cells induced similar EMT-like phenotypic changes to BRAF inhibitor treatment, whereas knocking down JUN abrogated the BRAF inhibitor-induced early adaptive changes associated with resistance and enhanced cell death. Combining the BRAF inhibitor with an inhibitor of c-JUN amino-terminal kinase (JNK) reduced c-JUN phosphorylation, decreased cell migration, and increased cell death in melanoma cells. Gene expression data from a panel of melanoma cell lines and a patient cohort showed that JUN expression correlated with a mesenchymal gene signature, implicating c-JUN as a key mediator of the mesenchymal-like phenotype associated with drug resistance.

Degryse S, Cools J
JAK kinase inhibitors for the treatment of acute lymphoblastic leukemia.
J Hematol Oncol. 2015; 8:91 [PubMed] Free Access to Full Article Related Publications
Recent studies of acute lymphoblastic leukemia have identified activating mutations in components of the interleukin-7 receptor complex (IL7R, JAK1, and JAK3). It will be of interest to investigate both JAK1 and JAK3 kinase inhibitors as targeted agents for these leukemias.

Vicente C, Schwab C, Broux M, et al.
Targeted sequencing identifies associations between IL7R-JAK mutations and epigenetic modulators in T-cell acute lymphoblastic leukemia.
Haematologica. 2015; 100(10):1301-10 [PubMed] Free Access to Full Article Related Publications
T-cell acute lymphoblastic leukemia is caused by the accumulation of multiple oncogenic lesions, including chromosomal rearrangements and mutations. To determine the frequency and co-occurrence of mutations in T-cell acute lymphoblastic leukemia, we performed targeted re-sequencing of 115 genes across 155 diagnostic samples (44 adult and 111 childhood cases). NOTCH1 and CDKN2A/B were mutated/deleted in more than half of the cases, while an additional 37 genes were mutated/deleted in 4% to 20% of cases. We found that IL7R-JAK pathway genes were mutated in 27.7% of cases, with JAK3 mutations being the most frequent event in this group. Copy number variations were also detected, including deletions of CREBBP or CTCF and duplication of MYB. FLT3 mutations were rare, but a novel extracellular mutation in FLT3 was detected and confirmed to be transforming. Furthermore, we identified complex patterns of pairwise associations, including a significant association between mutations in IL7R-JAK genes and epigenetic regulators (WT1, PRC2, PHF6). Our analyses showed that IL7R-JAK genetic lesions did not confer adverse prognosis in T-cell acute lymphoblastic leukemia cases enrolled in the UK ALL2003 trial. Overall, these results identify interconnections between the T-cell acute lymphoblastic leukemia genome and disease biology, and suggest a potential clinical application for JAK inhibitors in a significant proportion of patients with T-cell acute lymphoblastic leukemia.

Wong SH, Goode DL, Iwasaki M, et al.
The H3K4-Methyl Epigenome Regulates Leukemia Stem Cell Oncogenic Potential.
Cancer Cell. 2015; 28(2):198-209 [PubMed] Free Access to Full Article Related Publications
The genetic programs that maintain leukemia stem cell (LSC) self-renewal and oncogenic potential have been well defined; however, the comprehensive epigenetic landscape that sustains LSC cellular identity and functionality is less well established. We report that LSCs in MLL-associated leukemia reside in an epigenetic state of relative genome-wide high-level H3K4me3 and low-level H3K79me2. LSC differentiation is associated with reversal of these broad epigenetic profiles, with concomitant downregulation of crucial MLL target genes and the LSC maintenance transcriptional program that is driven by the loss of H3K4me3, but not H3K79me2. The H3K4-specific demethylase KDM5B negatively regulates leukemogenesis in murine and human MLL-rearranged AML cells, demonstrating a crucial role for the H3K4 global methylome in determining LSC fate.

Idris SZ, Hassan N, Lee LJ, et al.
Increased regulatory T cells in acute lymphoblastic leukemia patients.
Hematology. 2015; 20(9):523-9 [PubMed] Related Publications
INTRODUCTION: Regulation in adaptive immune response balances a fine line that prevents instigation of self-damage or fall into unresponsiveness permitting abnormal cell growth. Mechanisms that keep this balance in check include regulatory T cells (Tregs). Tregs consist of a small but heterogeneous population which may be identified by the phenotype, CD3+CD4+CD25+CD127-. Role of Tregs in pathogenesis of cancers is thus far supported by evidence of increased Tregs in various cancers and may contribute to poorer prognosis. Tregs may also be important in acute leukemias.
OBJECTIVE: A review of the literature on Tregs in acute leukemias was conducted and Tregs were determined in B-cell acute lymphoblastic leukemias (ALLs).
RESULTS: Studies on Tregs in B-cell ALL are few and controversial. We observed a significantly increased percentage of Tregs (mean ± SD, 9.72 ± 3.79% vs. 7.05 ± 1.74%; P = 0.047) in the bone marrow/peripheral blood of ALL (n = 17) compared to peripheral blood of normal controls (n = 35). A positive trend between Tregs and age (R = 0.474, P = 0.055, n = 17) implicates this factor of poor prognosis in B-cell ALL.
DISCUSSION: Tregs in cancer are particularly significant in immunotherapy. The manipulation of the immune system to treat cancer has for a long time ignored regulatory mechanisms inducible or in place. In lymphoma studies tumor-specific mechanisms that are unlike conventional methods in the induction of Tregs have been hypothesized. In addition, tumor-infiltrating Tregs may present different profiles from peripheral blood pictures. Tregs will continue to be dissected to reveal their mysteries and their impact on clinical significance.

Sanmamed MF, Rodriguez I, Schalper KA, et al.
Nivolumab and Urelumab Enhance Antitumor Activity of Human T Lymphocytes Engrafted in Rag2-/-IL2Rγnull Immunodeficient Mice.
Cancer Res. 2015; 75(17):3466-78 [PubMed] Related Publications
A current pressing need in cancer immunology is the development of preclinical model systems that are immunocompetent for the study of human tumors. Here, we report the development of a humanized murine model that can be used to analyze the pharmacodynamics and antitumor properties of immunostimulatory monoclonal antibodies (mAb) in settings where the receptors targeted by the mAbs are expressed. Human lymphocytes transferred into immunodeficient mice underwent activation and redistribution to murine organs, where they exhibited cell-surface expression of hCD137 and hPD-1. Systemic lymphocyte infiltrations resulted in a lethal CD4(+) T cell-mediated disease (xenograft-versus-host disease), which was aggravated when murine subjects were administered clinical-grade anti-hCD137 (urelumab) and anti-hPD-1 (nivolumab). In mice engrafted with human colorectal HT-29 carcinoma cells and allogeneic human peripheral blood mononuclear cells (PBMC), or with a patient-derived gastric carcinoma and PBMCs from the same patient, we found that coadministration of urelumab and nivolumab was sufficient to significantly slow tumor growth. Correlated with this result were increased numbers of activated human T lymphocytes producing IFNγ and decreased numbers of human regulatory T lymphocytes in the tumor xenografts, possibly explaining the efficacy of the therapeutic regimen. Our results offer a proof of concept for the use of humanized mouse models for surrogate efficacy and histology investigations of immune checkpoint drugs and their combinations.

Durinck K, Van Loocke W, Van der Meulen J, et al.
Characterization of the genome-wide TLX1 binding profile in T-cell acute lymphoblastic leukemia.
Leukemia. 2015; 29(12):2317-27 [PubMed] Related Publications
The TLX1 transcription factor is critically involved in the multi-step pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL) and often cooperates with NOTCH1 activation during malignant T-cell transformation. However, the exact molecular mechanism by which these T-cell specific oncogenes cooperate during transformation remains to be established. Here, we used chromatin immunoprecipitation followed by sequencing to establish the genome-wide binding pattern of TLX1 in human T-ALL. This integrative genomics approach showed that ectopic TLX1 expression drives repression of T cell-specific enhancers and mediates an unexpected transcriptional antagonism with NOTCH1 at critical target genes, including IL7R and NOTCH3. These phenomena coordinately trigger a TLX1-driven pre-leukemic phenotype in human thymic precursor cells, reminiscent of the thymus regression observed in murine TLX1 tumor models, and create a strong genetic pressure for acquiring activating NOTCH1 mutations as a prerequisite for full leukemic transformation. In conclusion, our results uncover a functional antagonism between cooperative oncogenes during the earliest phases of tumor development and provide novel insights in the multi-step pathogenesis of TLX1-driven human leukemia.

Chandran SS, Paria BC, Srivastava AK, et al.
Tumor-Specific Effector CD8+ T Cells That Can Establish Immunological Memory in Humans after Adoptive Transfer Are Marked by Expression of IL7 Receptor and c-myc.
Cancer Res. 2015; 75(16):3216-26 [PubMed] Free Access to Full Article Related Publications
The optimal T-cell attributes for adoptive cancer immunotherapy are unclear. Recent clinical trials of ex vivo-expanded tumor-infiltrating lymphocytes indicated that differentiated T effector cells can elicit durable antitumor responses in some patients with cancer, with their antitumor activity tightly correlated with their persistence in the host. Thus, there is great interest in the definition of intrinsic biomarkers that can predict the conversion of short-lived tumor antigen-specific T effector cells into long-lived T memory cells. Long-term persistence of ex vivo-expanded tumor-specific CD8+ T effector clones has been reported in refractory metastatic melanoma patients after adoptive T-cell transfer. By using highly homogeneous clone populations from these preparations, we performed a comparative transcriptional profiling to define preinfusion molecular attributes that can be ascribed to an effector-to-memory transition. Through this route, we discovered that preinfusion T-cell clones that expressed the IL7 receptor (IL7R) and c-myc were more likely to persist longer after adoptive transfer to patients. The predictive value of these two biomarkers was strengthened by using IL7R protein, IL7-induced pSTAT5, and c-myc mRNA expression to prospectively identify human tumor-specific T effector clones capable of engraftment into immunodeficient mice. Overall, our findings reveal IL7R and c-myc expression as intrinsic biomarkers that can predict the fate of CD8+ T effector cells after adoptive transfer.

Furlow PW, Zhang S, Soong TD, et al.
Mechanosensitive pannexin-1 channels mediate microvascular metastatic cell survival.
Nat Cell Biol. 2015; 17(7):943-52 [PubMed] Free Access to Full Article Related Publications
During metastatic progression, circulating cancer cells become lodged within the microvasculature of end organs, where most die from mechanical deformation. Although this phenomenon was first described over a half-century ago, the mechanisms enabling certain cells to survive this metastasis-suppressive barrier remain unknown. By applying whole-transcriptome RNA-sequencing technology to isogenic cancer cells of differing metastatic capacities, we identified a mutation encoding a truncated form of the pannexin-1 (PANX1) channel, PANX1(1-89), as recurrently enriched in highly metastatic breast cancer cells. PANX1(1-89) functions to permit metastatic cell survival during traumatic deformation in the microvasculature by augmenting ATP release from mechanosensitive PANX1 channels activated by membrane stretch. PANX1-mediated ATP release acts as an autocrine suppressor of deformation-induced apoptosis through P2Y-purinergic receptors. Finally, small-molecule therapeutic inhibition of PANX1 channels is found to reduce the efficiency of breast cancer metastasis. These data suggest a molecular basis for metastatic cell survival on microvasculature-induced biomechanical trauma.

Lee HJ, Lee JJ, Song IH, et al.
Prognostic and predictive value of NanoString-based immune-related gene signatures in a neoadjuvant setting of triple-negative breast cancer: relationship to tumor-infiltrating lymphocytes.
Breast Cancer Res Treat. 2015; 151(3):619-27 [PubMed] Related Publications
The prognostic significance of tumor-infiltrating lymphocytes and immune signals has been described previously in triple-negative breast cancer (TNBC). Furthermore, recent studies have shown that immunologic parameters are relevant for the response to neoadjuvant chemotherapy (NAC) in breast cancer as well as for outcomes after adjuvant chemotherapy. However, immune signals are variable, and which signals are important is largely unknown. We, therefore, evaluated the expression of immune-related genes in TNBC treated with NAC. We retrospectively evaluated biopsy tissue from 55 patients with primary TNBC treated with NAC (anthracycline, cyclophosphamide, and docetaxel) against the NanoString nCounter GX Human Immunology Panel (579 immune-related genes). Higher expression of cytotoxic molecules, T cell receptor signaling pathway components, cytokines related to T helper cell type 1 (Th1), and B cell markers was associated with a pathologic complete response (pCR). Higher expression of NFKB1, MAPK1, TRAF1, CXCL13, GZMK, and IL7R was significantly associated with pCR, higher Miller-Payne grade, and lower residual cancer burden class. Expression of NFKB1, TRAF1, and CXCL13genes, in particular, was significantly correlated with a longer disease-free survival rate. Conversely, patients those who failed to achieve a pCR showed increased expression of genes related to neutrophils. Higher expression of cytotoxic molecules, T cell receptor signaling pathway components, Th1-related cytokines, and B cell markers is correlated with pCR and survival in TNBC patients treated with NAC. Our results suggest that the activation status of neutrophils may provide additional predictive information for TNBC patients treated with NAC.

Lamhamedi-Cherradi SE, Menegaz BA, Ramamoorthy V, et al.
An Oral Formulation of YK-4-279: Preclinical Efficacy and Acquired Resistance Patterns in Ewing Sarcoma.
Mol Cancer Ther. 2015; 14(7):1591-604 [PubMed] Related Publications
Ewing sarcoma is a transcription factor-mediated pediatric bone tumor caused by a chromosomal translocation of the EWSR1 gene and one of several genes in the ETS family of transcription factors, typically FLI1 or ERG. Full activity of the resulting oncogenic fusion protein occurs only after binding RNA helicase A (RHA), and novel biologically targeted small molecules designed to interfere with that interaction have shown early promise in the preclinical setting. Herein, we demonstrate marked preclinical antineoplastic activity of an orally bioavailable formulation of YK-4-279 and identify mechanisms of acquired chemotherapy resistance that may be exploited to induce collateral sensitivity. Daily enteral administration of YK-4-279 led to significant delay in Ewing sarcoma tumor growth within a murine model. In advance of anticipated early-phase human clinical trials, we investigated both de novo and acquired mechanism(s) by which Ewing sarcoma cells evade YK-4-279-mediated cell death. Drug-resistant clones, formed by chronic in vitro exposure to steadily increased levels of YK-4-279, overexpressed c-Kit, cyclin D1, pStat3(Y705), and PKC isoforms. Interestingly, cross-resistance to imatinib and enzastaurin (selective inhibitors of c-Kit and PKC-β, respectively), was observed and the use of YK-4-279 with enzastaurin in vitro led to marked drug synergy, suggesting a potential role for combination therapies in the future. By advancing an oral formulation of YK-4-279 and identifying prominent mechanisms of resistance, this preclinical research takes us one step closer to a shared goal of curing adolescents and young adults afflicted by Ewing sarcoma.

Webb JR, Milne K, Nelson BH
PD-1 and CD103 Are Widely Coexpressed on Prognostically Favorable Intraepithelial CD8 T Cells in Human Ovarian Cancer.
Cancer Immunol Res. 2015; 3(8):926-35 [PubMed] Related Publications
αE(CD103)β7 is a TGFβ-regulated integrin that mediates retention of lymphocytes in peripheral tissues by binding to E-cadherin expressed on epithelial cells. We recently reported that αE(CD103)β7 specifically demarcates intraepithelial CD8(+) tumor-infiltrating lymphocytes (CD8 TIL) in ovarian cancer and that CD103(+) TIL have a surface profile consistent with an active effector phenotype (HLA-DR(+), Ki67(+), and CD127(lo)). These findings led us to hypothesize that, over time, CD103-mediated retention of CD8 TIL within the tumor epithelium might result in chronic stimulation by tumor antigen, which in turn might lead to an exhausted phenotype. To investigate this possibility, we evaluated PD-1 expression in a large cohort of ovarian tumors (N = 489) with known CD103(+) TIL content. PD-1(+) cells were present in 38.5% of high-grade serous carcinomas (HGSC), but were less prevalent in other histologic subtypes. PD-1(+) TIL were strongly associated with increased disease-specific survival in HGSC (HR, 0.4864; P = 0.0007). Multicolor immunohistochemistry and flow cytometry revealed a high degree of PD-1 and CD103 coexpression, specifically within the CD8 TIL compartment. PD-1(+)CD103(+) CD8 TIL were quiescent when assessed directly ex vivo yet were capable of robust cytokine production after pharmacologic stimulation. Moreover, they showed negligible expression of additional exhaustion-associated markers, including TIM-3, CTLA-4, and LAG-3. Thus, as hypothesized, CD103(+) CD8 TIL express PD-1 and appear quiescent in the tumor microenvironment. However, these cells retain functional competence and demonstrate strong prognostic significance. We speculate that, after standard treatment, PD-1(+)CD103(+) CD8 TIL might regain functional antitumor activity, an effect that potentially could be augmented by immune modulation.

Alonso S, Su M, Jones JW, et al.
Human bone marrow niche chemoprotection mediated by cytochrome P450 enzymes.
Oncotarget. 2015; 6(17):14905-12 [PubMed] Free Access to Full Article Related Publications
Substantial evidence now demonstrates that interactions between the tumor microenvironment and malignant cells are a critical component of clinical drug resistance. However, the mechanisms responsible for microenvironment-mediated chemoprotection remain unclear. We showed that bone marrow (BM) stromal cytochrome P450 (CYP)26 enzymes protect normal hematopoietic stem cells (HSCs) from the pro-differentiation effects of retinoic acid. Here, we investigated if stromal expression of CYPs is a general mechanism of chemoprotection. We found that similar to human hepatocytes, human BM-derived stromal cells expressed a variety of drug-metabolizing enzymes. CYP3A4, the liver's major drug-metabolizing enzyme, was at least partially responsible for BM stroma's ability to protect multiple myeloma (MM) and leukemia cells from bortezomib and etoposide, respectively, both in vitro and in vivo. Moreover, clarithromycin overcame stromal-mediated MM resistance to dexamethasone, suggesting that CYP3A4 inhibition plays a role in its ability to augment the activity of lenalidomide and dexamethasone as part of the BiRd regimen. We uncovered a novel mechanism of microenvironment-mediated drug resistance, whereby the BM niche creates a sanctuary site from drugs. Targeting these sanctuaries holds promise for eliminating minimal residual tumor and improving cancer outcomes.

Zhao Y, Zhang X, Zhao Y, et al.
Identification of potential therapeutic target genes, key miRNAs and mechanisms in acute myeloid leukemia based on bioinformatics analysis.
Med Oncol. 2015; 32(5):152 [PubMed] Related Publications
The study was aimed to explore the underlying mechanisms and identify the potential target genes and key miRNAs for acute myeloid leukemia (AML) treatment by bioinformatics analysis. The microarray data of GSE9476 were downloaded from Gene Expression Omnibus database. A total of 64 samples, including 26 AML and 38 normal samples, were used to identify differentially expressed genes (DEGs) between AML and normal samples. The functional enrichment analysis was performed, and protein-protein interaction (PPI) network of the DEGs was constructed by Cytoscape software. Besides, the target miRNAs for DEGs were identified. Totally, 323 DEGs were identified, including 87 up-regulated and 236 down-regulated genes. Not only up-regulated genes but also down-regulated genes were related to hematopoietic-related functions. Besides, down-regulated genes were also enriched in primary immunodeficiency pathway. Tumor necrosis factor (TNF), interleukin 7 receptor (IL7R), lymphocyte-specific protein tyrosine kinase (LCK), CD79a molecule and immunoglobulin-associated alpha (CD79A) were identified in these functions. TNF and LCK were hub nodes in PPI networks. miR-124 and miR-181 were important miRNAs in this study. The hematopoietic-related functions and primary immunodeficiency pathway may be associated with AML development. Genes, such as TNF, IL7R, LCK and CD79A, may be potential therapeutic target genes for AML, and miR-124 and miR-181 may be key miRNAs in AML development.

Verner J, Trbusek M, Chovancova J, et al.
NOD/SCID IL2Rγ-null mouse xenograft model of human p53-mutated chronic lymphocytic leukemia and ATM-mutated mantle cell lymphoma using permanent cell lines.
Leuk Lymphoma. 2015; 56(11):3198-206 [PubMed] Related Publications
Xenograft models represent a promising tool to study the pathogenesis of hematological malignancies. To establish a reliable and appropriate in vivo model of aggressive human B-cell leukemia and lymphoma we xenotransplanted four p53-mutated cell lines and one ATM-mutated cell line into immunodeficient NOD/SCID IL2Rγ-null mice. The cell lines MEC-1, SU-DHL-4, JEKO-1, REC-1, and GRANTA-519 were transplanted intraperitoneally or subcutaneously and the engraftment was investigated using immunohistochemistry and flow cytometry. We found significant differences in engraftment efficiency. MEC-1, JEKO-1 and GRANTA-519 cell lines engrafted most efficiently, while SU-DHL-4 cells did not engraft at all. MEC-1 and GRANTA-519 massively infiltrated organs and the whole intraperitoneal cavity showing very aggressive growth. In addition, GRANTA-519 cells massively migrated to the bone marrow regardless of the transplantation route. The MEC-1 and GRANTA-519 cells can be especially recommended for in vivo study of p53-mutated chronic lymphocytic leukemia and ATM-mutated mantle cell lymphoma, respectively.

Cheah MT, Chen JY, Sahoo D, et al.
CD14-expressing cancer cells establish the inflammatory and proliferative tumor microenvironment in bladder cancer.
Proc Natl Acad Sci U S A. 2015; 112(15):4725-30 [PubMed] Free Access to Full Article Related Publications
Nonresolving chronic inflammation at the neoplastic site is consistently associated with promoting tumor progression and poor patient outcomes. However, many aspects behind the mechanisms that establish this tumor-promoting inflammatory microenvironment remain undefined. Using bladder cancer (BC) as a model, we found that CD14-high cancer cells express higher levels of numerous inflammation mediators and form larger tumors compared with CD14-low cells. CD14 antigen is a glycosyl-phosphatidylinositol (GPI)-linked glycoprotein and has been shown to be critically important in the signaling pathways of Toll-like receptor (TLR). CD14 expression in this BC subpopulation of cancer cells is required for increased cytokine production and increased tumor growth. Furthermore, tumors formed by CD14-high cells are more highly vascularized with higher myeloid cell infiltration. Inflammatory factors produced by CD14-high BC cells recruit and polarize monocytes and macrophages to acquire immune-suppressive characteristics. In contrast, CD14-low BC cells have a higher baseline cell division rate than CD14-high cells. Importantly, CD14-high cells produce factors that further increase the proliferation of CD14-low cells. Collectively, we demonstrate that CD14-high BC cells may orchestrate tumor-promoting inflammation and drive tumor cell proliferation to promote tumor growth.

Goossens S, Radaelli E, Blanchet O, et al.
ZEB2 drives immature T-cell lymphoblastic leukaemia development via enhanced tumour-initiating potential and IL-7 receptor signalling.
Nat Commun. 2015; 6:5794 [PubMed] Free Access to Full Article Related Publications
Early T-cell precursor leukaemia (ETP-ALL) is a high-risk subtype of human leukaemia that is poorly understood at the molecular level. Here we report translocations targeting the zinc finger E-box-binding transcription factor ZEB2 as a recurrent genetic lesion in immature/ETP-ALL. Using a conditional gain-of-function mouse model, we demonstrate that sustained Zeb2 expression initiates T-cell leukaemia. Moreover, Zeb2-driven mouse leukaemia exhibit some features of the human immature/ETP-ALL gene expression signature, as well as an enhanced leukaemia-initiation potential and activated Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signalling through transcriptional activation of IL7R. This study reveals ZEB2 as an oncogene in the biology of immature/ETP-ALL and paves the way towards pre-clinical studies of novel compounds for the treatment of this aggressive subtype of human T-ALL using our Zeb2-driven mouse model.

Fogal V, Babic I, Chao Y, et al.
Mitochondrial p32 is upregulated in Myc expressing brain cancers and mediates glutamine addiction.
Oncotarget. 2015; 6(2):1157-70 [PubMed] Free Access to Full Article Related Publications
Metabolic reprogramming is a key feature of tumorigenesis that is controlled by oncogenes. Enhanced utilization of glucose and glutamine are the best-established hallmarks of tumor metabolism. The oncogene c-Myc is one of the major players responsible for this metabolic alteration. However, the molecular mechanisms involved in Myc-induced metabolic reprogramming are not well defined. Here we identify p32, a mitochondrial protein known to play a role in the expression of mitochondrial respiratory chain complexes, as a critical player in Myc-induced glutamine addiction. We show that p32 is a direct transcriptional target of Myc and that high level of Myc in malignant brain cancers correlates with high expression of p32. Attenuation of p32 expression reduced growth rate of glioma cells expressing Myc and impaired tumor formation in vivo. Loss of p32 in glutamine addicted glioma cells induced resistance to glutamine deprivation and imparted sensitivity to glucose withdrawal. Finally, we provide evidence that p32 expression contributes to Myc-induced glutamine addiction of cancer cells. Our findings suggest that Myc promotes the expression of p32, which is required to maintain sufficient respiratory capacity to sustain glutamine metabolism in Myc transformed cells.

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