Gene Summary

Gene:LMO2; LIM domain only 2
Aliases: TTG2, LMO-2, RBTN2, RHOM2, RBTNL1
Summary:LMO2 encodes a cysteine-rich, two LIM-domain protein that is required for yolk sac erythropoiesis. The LMO2 protein has a central and crucial role in hematopoietic development and is highly conserved. The LMO2 transcription start site is located approximately 25 kb downstream from the 11p13 T-cell translocation cluster (11p13 ttc), where a number T-cell acute lymphoblastic leukemia-specific translocations occur. Alternative splicing results in multiple transcript variants encoding different isoforms.[provided by RefSeq, Nov 2008]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Source:NCBIAccessed: 31 August, 2019


What does this gene/protein do?
Show (18)

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 31 August 2019 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.

  • Childhood Cancer
  • Signal Transducing Adaptor Proteins
  • Mice, Transgenic
  • Insertional Mutagenesis
  • DNA-Binding Proteins
  • Thymus Neoplasms
  • Tetraspanins
  • United States Food and Drug Administration
  • Leukemic Gene Expression Regulation
  • T-Cell Leukemia
  • Adult T-Cell Leukemia-Lymphoma
  • Chromosome 11
  • X-Linked Combined Immunodeficiency Diseases
  • Homeodomain Proteins
  • Cell Differentiation
  • Genetic Therapy
  • Molecular Sequence Data
  • Young Adult
  • Up-Regulation
  • LMO2
  • Proto-Oncogene Proteins
  • Neoplastic Cell Transformation
  • Metalloproteins
  • Tumor Necrosis Factor Receptor Superfamily, Member 9
  • Tumor Suppressor Proteins
  • Leukaemia
  • Base Sequence
  • Diffuse Large B-Cell Lymphoma
  • Biomarkers, Tumor
  • Hematopoiesis
  • SCID
  • LIM Domain Proteins
  • Gene Expression Profiling
  • Neoplasm Proteins
  • Oncogenes
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma
  • Oligonucleotide Array Sequence Analysis
  • Basic Helix-Loop-Helix Transcription Factors
  • Adolescents
  • Cancer Gene Expression Regulation
  • Acute Lymphocytic Leukaemia
Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (1)

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: LMO2 (cancer-related)

Ginn SL, McCormack MP, Alexander IE
Thymocyte self-renewal and oncogenic risk in immunodeficient mouse models: relevance for human gene therapy clinical trials targeting haematopoietic stem cell populations?
Mamm Genome. 2018; 29(11-12):771-776 [PubMed] Related Publications
Emerging evidence indicates that thymocyte self-renewal induced by progenitor deprivation carries an oncogenic risk that is modulated by intra-thymic competition from differentiation-committed cells. Here we discuss formative studies demonstrating that, in mice, early thymocytes acquire self-renewing potential when thymic progenitor supply is sub-physiological and the importance of cellular competition with this at-risk cell population to prevent lymphoid malignancy. We also consider the possibility that increased thymic residency time, established under conditions of limited cellular competition, may have contributed to oncogenesis observed in early SCID-X1 trials when combined with insertional activation of proto-oncogenes such as LMO2.

Wu C, Li J, Tian C, et al.
Epigenetic dysregulation of ZEB1 is involved in LMO2-promoted T-cell acute lymphoblastic leukaemia leukaemogenesis.
Biochim Biophys Acta Mol Basis Dis. 2018; 1864(8):2511-2525 [PubMed] Related Publications
T-cell acute lymphoblastic leukaemia (T-ALL) is a hematological malignancy caused by the accumulation of genomic lesions that affect the development of T-cells. ZEB1, a member of zinc finger-homeodomain family transcription factor, exhibits crucial function in promoting T-cell differentiation and potentially acts as a tumor suppressor in T-ALL. However, the molecular mechanism by which ZEB1 regulates T-ALL leukaemogenesis remains obscure. Here, we showed that oncogenic LIM only 2 (LMO2) could recruit Sap18 and HDAC1 to assemble an epigenetic regulatory complex, thus inducing histone deacetylation in ZEB1 promoter and chromatin remodeling to achieve transcriptional repression. Furthermore, downregulation of ZEB1 by LMO2 complex results in an increased leukaemia stem cell (LSC) phenotype as well as unsensitivity in response to methotrexate (MTX) chemotherapy in T-ALL cells. Importantly, we demonstrated that Trichostatin A (TSA, a HDAC inhibitor) addition significantly attenuates MTX unsensitivity caused by dysfunction of LMO2/ZEB1 signaling. In conclusion, these findings have identified a molecular mechanism underlying LMO2/ZEB1-mediated leukaemogenesis, paving a way for treating T-ALL with a new strategy of epigenetic inhibitors.

Rymkiewicz G, Grygalewicz B, Chechlinska M, et al.
A comprehensive flow-cytometry-based immunophenotypic characterization of Burkitt-like lymphoma with 11q aberration.
Mod Pathol. 2018; 31(5):732-743 [PubMed] Related Publications
We previously described a subset of MYC translocation-negative aggressive B-cell lymphomas resembling Burkitt lymphoma, characterized by proximal gains and distal losses in chromosome 11. In the 2016 WHO classification, these MYC-negative lymphomas were recognized as a new provisional entity, 'Burkitt-like lymphoma with 11q aberration'. Here we present an immunophenotype analysis of Burkitt-like lymphomas with 11q aberration. Cells were acquired by fine needle aspiration biopsy from 10 young adult patients, 80% of whom presented recurrence-free 5-year survival. Twenty-three MYC-positive Burkitt lymphomas, including three carrying both MYC rearrangement and 11q aberration, served as controls. By immunohistochemistry, all Burkitt-like lymphomas with 11q aberration were CD20+/CD10+/BCL6+/BCL2-/MUM1-/MYC+/EBV-, usually LMO2+/CD44-/CD43- and sometimes CD56+, and showed high proliferation rate. By flow cytometry, Burkitt-like lymphoma with 11q aberration immunophenotypically resembled MYC-positive Burkitt lymphoma, except for significantly (adjusted P<0.001) more frequent CD38

Miyashita K, Kitajima K, Goyama S, et al.
Overexpression of Lhx2 suppresses proliferation of human T cell acute lymphoblastic leukemia-derived cells, partly by reducing LMO2 protein levels.
Biochem Biophys Res Commun. 2018; 495(3):2310-2316 [PubMed] Related Publications
T cell acute lymphoblastic leukemia (T-ALL) is a malignant cancer with poor prognosis. The transcriptional co-factor LIM domain only 2 (LMO2) and its target gene HHEX are essential for self-renewal of T cell precursors and T-ALL etiology. LMO2 directly associates with LDB1 in a large DNA-containing nuclear complex and controls the transcription of T-ALL-related genes. Recently, we reported that overexpression of the LIM-homeodomain transcription factor, Lhx2, results in liberation of the Lmo2 protein from the Lmo2-Ldb1 complex, followed by ubiquitin proteasome mediated degradation. Here, we found that proliferation of five human T-ALL-derived cell lines, including CCRF-CEM, was significantly suppressed by retroviral overexpression of Lhx2. The majority of Lhx2-transduced CCRF-CEM cells arrested in G

Kunder CA, Roncador G, Advani RH, et al.
KLHL6 Is Preferentially Expressed in Germinal Center-Derived B-Cell Lymphomas.
Am J Clin Pathol. 2017; 148(6):465-476 [PubMed] Free Access to Full Article Related Publications
Objectives: KLHL6 is a recently described BTB-Kelch protein with selective expression in lymphoid tissues and is most strongly expressed in germinal center B cells.
Methods: Using gene expression profiling as well as immunohistochemistry with an anti-KLHL6 monoclonal antibody, we have characterized the expression of this molecule in normal and neoplastic tissues. Protein expression was evaluated in 1,058 hematopoietic neoplasms.
Results: Consistent with its discovery as a germinal center marker, KLHL6 was positive mainly in B-cell neoplasms of germinal center derivation, including 95% of follicular lymphomas (106/112). B-cell lymphomas of non-germinal center derivation were generally negative (0/33 chronic lymphocytic leukemias/small lymphocytic lymphomas, 3/49 marginal zone lymphomas, and 2/66 mantle cell lymphomas).
Conclusions: In addition to other germinal center markers, including BCL6, CD10, HGAL, and LMO2, KLHL6 immunohistochemistry may prove a useful adjunct in the diagnosis and future classification of B-cell lymphomas.

Bosch M, Akhter A, Chen BE, et al.
A bioclinical prognostic model using MYC and BCL2 predicts outcome in relapsed/refractory diffuse large B-cell lymphoma.
Haematologica. 2018; 103(2):288-296 [PubMed] Free Access to Full Article Related Publications
The objective of this study was to create a bioclinical model, based on clinical and molecular predictors of event-free and overall survival for relapsed/refractory diffuse large B-cell lymphoma patients treated on the Canadian Cancer Trials Group (CCTG) LY12 prospective study. In 91 cases, sufficient histologic material was available to create tissue microarrays and perform immunohistochemistry staining for CD10, BCL6, MUM1/IRF4, FOXP1, LMO2, BCL2, MYC, P53 and phosphoSTAT3 (pySTAT3) expression. Sixty-seven cases had material sufficient for fluorescent

Choi A, Illendula A, Pulikkan JA, et al.
RUNX1 is required for oncogenic
Blood. 2017; 130(15):1722-1733 [PubMed] Free Access to Full Article Related Publications
The gene encoding the RUNX1 transcription factor is mutated in a subset of T-cell acute lymphoblastic leukemia (T-ALL) patients, and

Efimenko E, Davé UP, Lebedeva IV, et al.
PI3Kγ/δ and NOTCH1 Cross-Regulate Pathways That Define the T-cell Acute Lymphoblastic Leukemia Disease Signature.
Mol Cancer Ther. 2017; 16(10):2069-2082 [PubMed] Free Access to Full Article Related Publications
PI3K/AKT and NOTCH1 signaling pathways are frequently dysregulated in T-cell acute lymphoblastic leukemias (T-ALL). Although we have shown that the combined activities of the class I PI3K isoforms p110γ and p110δ play a major role in the development and progression of PTEN-null T-ALL, it has yet to be determined whether their contribution to leukemogenic programing is unique from that associated with NOTCH1 activation. Using an

Busse TM, Roth JJ, Wilmoth D, et al.
Copy number alterations determined by single nucleotide polymorphism array testing in the clinical laboratory are indicative of gene fusions in pediatric cancer patients.
Genes Chromosomes Cancer. 2017; 56(10):730-749 [PubMed] Related Publications
Gene fusions resulting from structural rearrangements are an established mechanism of tumorigenesis in pediatric cancer. In this clinical cohort, 1,350 single nucleotide polymorphism (SNP)-based chromosomal microarrays from 1,211 pediatric cancer patients were evaluated for copy number alterations (CNAs) associated with gene fusions. Karyotype or fluorescence in situ hybridization studies were performed in 42% of the patients. Ten percent of the bone marrow or solid tumor specimens had SNP array-associated CNAs suggestive of a gene fusion. Alterations involving ETV6, ABL1-NUP214, EBF1-PDGFRB, KMT2A(MLL), LMO2-RAG, MYH11-CBFB, NSD1-NUP98, PBX1, STIL-TAL1, ZNF384-TCF3, P2RY8-CRLF2, and RUNX1T1-RUNX1 fusions were detected in the bone marrow samples. The most common alteration among the low-grade gliomas was a 7q34 tandem duplication resulting in a KIAA1549-BRAF fusion. Additional fusions identified in the pediatric brain tumors included FAM131B-BRAF and RAF1-QKI. COL1A1-PDGFB, CRTC1-MAML2, EWSR1, HEY1, PAX3- and PAX7-FOXO1, and PLAG1 fusions were determined in a variety of solid tumors and a novel potential gene fusion, FGFR1-USP6, was detected in an aneurysmal bone cyst. The identification of these gene fusions was instrumental in tumor diagnosis. In contrast to hematologic and solid tumors in adults that are predominantly driven by mutations, the majority of hematologic and solid tumors in children are characterized by CNAs and gene fusions. Chromosomal microarray analysis is therefore a robust platform to identify diagnostic and prognostic markers in the clinical setting.

Hu Y, Yoshida T, Georgopoulos K
Transcriptional circuits in B cell transformation.
Curr Opin Hematol. 2017; 24(4):345-352 [PubMed] Free Access to Full Article Related Publications
PURPOSE OF REVIEW: Loss of IKAROS in committed B cell precursors causes a block in differentiation while at the same time augments aberrant cellular properties, such as bone marrow stromal adhesion, self-renewal and resistance to glucocorticoid-mediated cell death. B cell acute lymphoblastic leukaemias originating from these early stages of B cell differentiation and associated with IKAROS mutations share a high-risk cellular phenotype suggesting that deregulation of IKAROS-based mechanisms cause a highly malignant disease process.
RECENT STUDIES: Recent studies show that IKAROS is critical for the activity of super-enhancers at genes required for pre-B cell receptor (BCR) signalling and differentiation, working either downstream of or in parallel with B cell master regulators such as EBF1 and PAX5. IKAROS also directly represses a cryptic regulatory network of transcription factors prevalent in mesenchymal and epithelial precursors that includes YAP1, TEAD1/2, LHX2 and LMO2, and their targets, which are not normally expressed in lymphocytes. IKAROS prevents not only expression of these 'extra-lineage' transcription factors but also their cooperation with endogenous B cell master regulators, such as EBF1 and PAX5, leading to the formation of a de novo for lymphocytes super-enhancer network. IKAROS coordinates with the Polycomb repression complex (PRC2) to provide stable repression of associated genes during B cell development. However, induction of regulatory factors normally repressed by IKAROS starts a feed-forward loop that activates de-novo enhancers and elevates them to super-enhancer status, thereby diminishing PRC2 repression and awakening aberrant epithelial-like cell properties in B cell precursors.
SUMMARY: Insight into IKAROS-based transcriptional circuits not only sets new paradigms for cell differentiation but also provides new approaches for classifying and treating high-risk human B-ALL that originates from these early stages of B cell differentiation.

Idaghdour Y, Hodgkinson A
Integrated genomic analysis of mitochondrial RNA processing in human cancers.
Genome Med. 2017; 9(1):36 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The mitochondrial genome is transcribed as continuous polycistrons of RNA containing multiple genes. As a consequence, post-transcriptional events are critical for the regulation of gene expression and therefore all aspects of mitochondrial function. One particularly important process is the m
METHODS: We measure and assess mitochondrial RNA processing using integrated genomic analysis of RNA sequencing and genotyping data from 1226 samples across 12 different cancer types. We focus on the levels of m
RESULTS: We find significant changes to m
CONCLUSIONS: We report widespread variation of mitochondrial RNA processing between normal and tumor tissues across all cancer types investigated and show that these alterations are likely modulated by patient genotype and may impact patient survival outcomes. These results highlight the potential clinical relevance of altered mitochondrial RNA processing and provide broad new insights into the importance and complexity of these events in cancer.

Liau WS, Ngoc PC, Sanda T
Roles of the RUNX1 Enhancer in Normal Hematopoiesis and Leukemogenesis.
Adv Exp Med Biol. 2017; 962:139-147 [PubMed] Related Publications
Enhancers are regulatory elements in genomic DNA that contain specific sequence motifs that are bound by DNA-binding transcription factors. The activity of enhancers is tightly regulated in an integrated and combinatorial manner, thus yielding complex patterns of transcription in different tissues. Identifying enhancers is crucial to understanding the physiological and pathogenic roles of their target genes. The RUNX1 intronic enhancer, eR1, acts in cis to regulate RUNX1 gene expression in hematopoietic stem cells (HSCs) and hemogenic endothelial cells. RUNX1 and other hematopoietic transcription factors TAL1/SCL, GATA2, PU.1, LMO2 and LDB1 bind at this region. Interestingly, recent studies have revealed that this region is involved in a large cluster of enhancers termed a super-enhancer. The RUNX1 super-enhancer is observed in normal HSCs and T-cell acute lymphoblastic leukemia cells. In this review, we describe the discovery of eR1 and its roles in normal development and leukemogenesis, as well as its potential applications in stem cell research.

Colomo L, Vazquez I, Papaleo N, et al.
LMO2-negative Expression Predicts the Presence of MYC Translocations in Aggressive B-Cell Lymphomas.
Am J Surg Pathol. 2017; 41(7):877-886 [PubMed] Related Publications
MYC translocation is a defining feature of Burkitt lymphoma (BL), and the new category of high-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 translocations, and occurs in 6% to 15% of diffuse large B-cell lymphomas (DLBCLs). The low incidence of MYC translocations in DLBCL makes the genetic study of all these lymphomas cumbersome. Strategies based on an initial immunophenotypic screening to select cases with a high probability of carrying the translocation may be useful. LMO2 is a germinal center marker expressed in most lymphomas originated in these cells. Mining gene expression profiling studies, we observed LMO2 downregulation in BL and large B-cell lymphoma (LBCL) with MYC translocations, and postulated that LMO2 protein expression could assist to identify such cases. We analyzed LMO2 protein expression in 46 BLs and 284 LBCL. LMO2 was expressed in 1/46 (2%) BL cases, 146/268 (54.5%) DLBCL cases, and 2/16 (12.5%) high-grade B-cell lymphoma cases with MYC and BCL2 and/or BCL6 translocations. All BLs carried MYC translocation (P<0.001), whereas LMO2 was only positive in 6/42 (14%) LBCL with MYC translocation (P<0.001). The relationship between LMO2 negativity and MYC translocation was further analyzed in different subsets of tumors according to CD10 expression and cell of origin. Lack of LMO2 expression was associated with the detection of MYC translocations with high sensitivity (87%), specificity (87%), positive predictive value and negative predictive value (74% and 94%, respectively), and accuracy (87%) in CD10 LBCL. Comparing LMO2 and MYC protein expression, all statistic measures of performance of LMO2 surpassed MYC in CD10 LBCL. These findings suggest that LMO2 loss may be a good predictor for the presence of MYC translocation in CD10 LBCL.

Rahman S, Magnussen M, León TE, et al.
Activation of the
Blood. 2017; 129(24):3221-3226 [PubMed] Free Access to Full Article Related Publications
Somatic mutations within noncoding genomic regions that aberrantly activate oncogenes have remained poorly characterized. Here we describe recurrent activating intronic mutations of

Abraham BJ, Hnisz D, Weintraub AS, et al.
Small genomic insertions form enhancers that misregulate oncogenes.
Nat Commun. 2017; 8:14385 [PubMed] Free Access to Full Article Related Publications
The non-coding regions of tumour cell genomes harbour a considerable fraction of total DNA sequence variation, but the functional contribution of these variants to tumorigenesis is ill-defined. Among these non-coding variants, somatic insertions are among the least well characterized due to challenges with interpreting short-read DNA sequences. Here, using a combination of Chip-seq to enrich enhancer DNA and a computational approach with multiple DNA alignment procedures, we identify enhancer-associated small insertion variants. Among the 102 tumour cell genomes we analyse, small insertions are frequently observed in enhancer DNA sequences near known oncogenes. Further study of one insertion, somatically acquired in primary leukaemia tumour genomes, reveals that it nucleates formation of an active enhancer that drives expression of the LMO2 oncogene. The approach described here to identify enhancer-associated small insertion variants provides a foundation for further study of these abnormalities across human cancers.

Porcher C, Chagraoui H, Kristiansen MS
SCL/TAL1: a multifaceted regulator from blood development to disease.
Blood. 2017; 129(15):2051-2060 [PubMed] Related Publications
SCL/TAL1 (stem cell leukemia/T-cell acute lymphoblastic leukemia [T-ALL] 1) is an essential transcription factor in normal and malignant hematopoiesis. It is required for specification of the blood program during development, adult hematopoietic stem cell survival and quiescence, and terminal maturation of select blood lineages. Following ectopic expression, SCL contributes to oncogenesis in T-ALL. Remarkably, SCL's activities are all mediated through nucleation of a core quaternary protein complex (SCL:E-protein:LMO1/2 [LIM domain only 1 or 2]:LDB1 [LIM domain-binding protein 1]) and dynamic recruitment of conserved combinatorial associations of additional regulators in a lineage- and stage-specific context. The finely tuned control of SCL's regulatory functions (lineage priming, activation, and repression of gene expression programs) provides insight into fundamental developmental and transcriptional mechanisms, and highlights mechanistic parallels between normal and oncogenic processes. Importantly, recent discoveries are paving the way to the development of innovative therapeutic opportunities in SCL

Liu Y, Wu C, Zhu T, Sun W
LMO2 Enhances Lamellipodia/Filopodia Formation in Basal-Type Breast Cancer Cells by Mediating ARP3-Profilin1 Interaction.
Med Sci Monit. 2017; 23:695-703 [PubMed] Free Access to Full Article Related Publications
BACKGROUND The human LMO2 gene was first cloned from an acute T lymphocytic leukemia patient; it is primarily expressed in hematopoietic and vascular endothelial systems, and functions as a pivotal transcriptional regulator during embryonic hematopoiesis and angiogenesis. However, some recent reports indicated that LMO2 is widely expressed in many tissues and tumors, predominantly in cytoplasm, and revealed complicated functions on tumor behaviors in a variety of cancer types. As an adaptor molecule, binding partners and function details of LMO2 in these solid tumors need to be further investigated. MATERIAL AND METHODS In this study, we used yeast two-hybrid method to screen potential LMO2 interacting partners, MBP-pulldown, and co-immunoprecipitation assay to confirm protein-protein interactions, and confocal microscopy to reveal the subcellular localization of relevant proteins and actin cytoskeleton changes in relevant cells. RESULTS We found that ARP3 and profilin1 were 2 binding partners of LMO2, primarily in cytoplasm. LMO2. Functionally, LMO2 mediated the assembly of a complex including ARP3, profilin1, and actin monomer, increased actin monomer binding to profilin1, and promoted lamellipodia/filopodia formation in basal-type breast cancer cells. CONCLUSIONS Our data indicate a novel functional mechanism of LMO2 in facilitating the delivery of actin monomers to the branched microfilament and increasing lamellipodia/filopodia formation in basal-type breast cancer cells, suggesting a cancer-promoting role of LMO2 in a subtype-dependent manner and its potential as a subtype-specific biomarker for clinical treatment of breast cancers.

Zamani-Ahmadmahmudi M, Aghasharif S, Ilbeigi K
Prognostic efficacy of the human B-cell lymphoma prognostic genes in predicting disease-free survival (DFS) in the canine counterpart.
BMC Vet Res. 2017; 13(1):17 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Canine B-cell lymphoma is deemed an ideal model of human non-Hodgkin's lymphoma where the lymphomas of both species share similar clinical features and biological behaviors. However there are some differences between tumor features in both species. In the current study, we sought to evaluate the prognostic efficacy of human B-cell lymphoma prognostic gene signatures in canine B-cell lymphoma.
METHODS: The corresponding probe sets of 36 human B-cell lymphoma prognostic genes were retrieved from 2 canine B-cell lymphoma microarray datasets (GSE43664 and GSE39365) (76 samples), and prognostic probe sets were thereafter detected using the univariate and multivariate Cox proportional-hazard model and the Kaplan-Meier analysis. The two datasets were employed both as training sets and as external validation sets for each other. Results were confirmed using quantitative real-time PCR (qRT-PCR) analysis.
RESULTS: In the univariate analysis, CCND1, CCND2, PAX5, CR2, LMO2, HLA-DQA1, P53, CD38, MYC-N, MYBL1, and BIRCS5 were associated with longer disease-free survival (DFS), while CD44, PLAU, and FN1 were allied to shorter DFS. However, the multivariate Cox proportional-hazard analysis confirmed CCND1 and BIRCS5 as prognostic genes for canine B-cell lymphoma. qRT-PCR used for verification of results indicated that expression level of CCND1 was significantly higher in B-cell lymphoma patients with the long DFS than ones with the short DFS, while expression level of BIRCS5 wasn't significantly different between two groups.
CONCLUSION: Our results confirmed CCND1 as important gene that can be used as a potential predictor in this tumor type.

Four M, Cacheux V, Tempier A, et al.
PD1 and PDL1 expression in primary central nervous system diffuse large B-cell lymphoma are frequent and expression of PD1 predicts poor survival.
Hematol Oncol. 2017; 35(4):487-496 [PubMed] Related Publications
Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is a rare and aggressive type of diffuse large B-cell lymphoma (DLBCL) whit poorly understood pathogenesis. Finding biomarkers associated with patient survival may be important for understanding its physiopathology and to develop new therapeutic approaches. We investigated 32 PCNS-DLBCL from immunocompetent patients for BCL2, CMYC, LMO2, and P53 expression and for cytogenetic aberrations of BCL2, BCL6, and MYC genes, all known for their prognostic value in systemic DLBCL (s-DLBCL). We analyzed PD1 and PDL1 protein expression in both tumor infiltrating lymphocytes (TILs) and tumor cells. Finally, we searched for correlation between biological data and clinical course. The PCNS-DLBCL expressed BCL2, CMYC, LMO2, and P53 at similar frequency than s-DLBCL but without significant prognostic on survival. None cases harbored aberrations involving BCL2 and MYC gene whereas BCL6 abnormalities were present in 20.7% of cases but without value on survival. Expression of PD1 in TILs and PDL1 in tumor cells was observed at higher rates than in s-DLBCL (58% and 37%, respectively). The PD1 expression in TILs correlated with PDL1 expression in tumor cells (P = .001). Presence of PD1 positive TILs was associated with poorer overall survival (P = .011). Patients with PDL1 overexpression tended to better response to chemotherapy (P = .23). In conclusion PCNS-DLBCL pathogenesis differs from s-DLBCL without prognostic value of the phenotypic and cytogenetic parameters known for their pejorative impact in the latter. The PD1/PDL1 pathway plays a strong role in PCNS-DLBCL and represents an attractive target for this aggressive lymphoma.

Liu Y, Wang Z, Huang D, et al.
LMO2 promotes tumor cell invasion and metastasis in basal-type breast cancer by altering actin cytoskeleton remodeling.
Oncotarget. 2017; 8(6):9513-9524 [PubMed] Free Access to Full Article Related Publications
LMO2 is traditionally recognized as a pivotal transcriptional regulator during embryonic hematopoiesis and angionenesis, and its ectopic expression in T lymphocyte progenitors is closely correlated to the onset of acute T lymphocytic leukemia. However, recently studies revealed complicated expression features and dual functions of LMO2 on tumor behaviors in a variety of cancer types, including breast cancers. Basal-type breast cancer is one of the breast cancer subtypes and a prognostically unfavorable subtype among all breast cancers. Herein we found that in basal-type breast cancer specifically, high LMO2 expression was positively correlated with lymph node metastases in patients, promoted tumor cell migration and invasion and increased distant metastasis in SCID mice. Moreover, the novel function of LMO2 was achieved by its predominantly cytoplasmic location and interaction with cofilin1, which is a critical regulator in actin cytoskeleton dynamics. These findings suggest a subtype-dependent role of LMO2 in breast cancers and the potential of LMO2 as a subtype-specific biomarker for clinical practice.

Mandoli A, Singh AA, Prange KHM, et al.
The Hematopoietic Transcription Factors RUNX1 and ERG Prevent AML1-ETO Oncogene Overexpression and Onset of the Apoptosis Program in t(8;21) AMLs.
Cell Rep. 2016; 17(8):2087-2100 [PubMed] Related Publications
The t(8;21) acute myeloid leukemia (AML)-associated oncoprotein AML1-ETO disrupts normal hematopoietic differentiation. Here, we have investigated its effects on the transcriptome and epigenome in t(8,21) patient cells. AML1-ETO binding was found at promoter regions of active genes with high levels of histone acetylation but also at distal elements characterized by low acetylation levels and binding of the hematopoietic transcription factors LYL1 and LMO2. In contrast, ERG, FLI1, TAL1, and RUNX1 bind at all AML1-ETO-occupied regulatory regions, including those of the AML1-ETO gene itself, suggesting their involvement in regulating AML1-ETO expression levels. While expression of AML1-ETO in myeloid differentiated induced pluripotent stem cells (iPSCs) induces leukemic characteristics, overexpression increases cell death. We find that expression of wild-type transcription factors RUNX1 and ERG in AML is required to prevent this oncogene overexpression. Together our results show that the interplay of the epigenome and transcription factors prevents apoptosis in t(8;21) AML cells.

Tekin N, Omidvar N, Morris TP, et al.
Protocol for qRT-PCR analysis from formalin fixed paraffin embedded tissue sections from diffuse large b-cell lymphoma: Validation of the six-gene predictor score.
Oncotarget. 2016; 7(50):83319-83329 [PubMed] Free Access to Full Article Related Publications
As a part of an international study on the molecular analysis of Diffuse Large B-cell Lymphoma (DLBCL), a robust protocol for gene expression analysis from RNA extraction to qRT-PCR using Formalin Fixed Paraffin Embedded tissues was developed. Here a study was conducted to define a strategy to validate the previously reported 6-gene (LMO2, BCL6, FN1, CCND2, SCYA3 and BCL2) model as predictor of prognosis in DLBCL. To avoid variation, all samples were tested in a single centre and single platform. This study comprised 8 countries (Brazil, Chile, Hungary, India, Philippines, S. Korea, Thailand and Turkey). Using the Kaplan-Meier and log rank test on patients (n=162) and two mortality risk groups (with those above and below the mean representing high and low risk groups) confirmed that the 6-gene predictor score correlates significantly with overall survival (OS, p<0.01) but not with event free survival (EFS, p=0.18). Adding the International Prognostic Index (IPI) shows that the 6-gene predictor score correlates significantly with high IPI scores for OS (p<0.05), whereas those with low IPI scores show a trend not reaching significance (p=0.08). This study defined an effective and economical qRT-PCR strategy and validated the 6-gene score as a predictor of OS in an international setting.

Wang X, Liu Y, Dai L, et al.
Foxp3 downregulation in NSCLC mediates epithelial-mesenchymal transition via NF-κB signaling.
Oncol Rep. 2016; 36(4):2282-8 [PubMed] Related Publications
Forkhead box P3 (Foxp3) is a member of forkhead box transcription factor family and it was identified as a tumor suppressor in various solid tumors. This study evaluated the expression of Foxp3 in non-small cell lung cancer (NSCLC) and investigated its role in epithelial‑mesenchymal transition (EMT) of cancer cells. qRT-PCR and western blot analysis were used for examining the expression of Foxp3 in NSCLC tissues and the non-tumor tissues. A tissue microarray was constructed and scored for evaluating the clinical significance of Foxp3 expression in NSCLC tissues. RNAi was employed for downregulating Foxp3 expression and cell proliferation was done with MTT assay. Transwell with or without basement membrane matrix was used for cell migration and invasion assay respectively. Foxp3 was found downregulated in NSCLC tissues compared with non-tumoral tissues; downregulation of Foxp3 predicted adverse tumor stage and overall survival; silencing of FOXP3 promoted the proliferation, migration and invasion ability of NSCLC cells and influenced the expression level of EMT-associated proteins. However, forced expression of Foxp3 could reverse this effect. Moreover, Foxp3 could interact with LMO2 and affect the expression level of TAL1, which was in accordance with the findings in T-cell acute lymphoblastic leukemia. By screening the signalling pathways, we observed an obvious upregulation of phosphorylated NF-κB in A549 and H520 cells after silencing of FOXP3. Our results suggest that Foxp3 suppressed NSCLC cell metastasis, at least partially, via NF-κB signaling.

Green TM, Jensen AK, Holst R, et al.
Multiplex polymerase chain reaction-based prognostic models in diffuse large B-cell lymphoma patients treated with R-CHOP.
Br J Haematol. 2016; 174(6):876-86 [PubMed] Related Publications
We present a multiplex analysis for genes known to have prognostic value in an attempt to design a clinically useful classification model in patients with diffuse large B-cell lymphoma (DLBCL). Real-time polymerase chain reaction was used to measure transcript levels of 28 relevant genes in 194 de novo DLBCL patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). Including International Prognostic Index (IPI) as a variable in a penalized Cox regression, we investigated the association with disease progression for single genes or gene combinations in four models. The best model was validated in data from an online available R-CHOP treated cohort. With progression-free survival (PFS) as primary endpoint, the best performing IPI independent model incorporated the LMO2 and HLADQA1 as well as gene interactions for GCSAMxMIB1, GCSAMxCTGF and FOXP1xPDE4B. This model assigned 33% of patients (n = 60) to poor outcome with an estimated 3-year PFS of 40% vs. 87% for low risk (n = 61) and intermediate (n = 60) risk groups (P < 0·001). However, a simpler, IPI independent model incorporated LMO2 and BCL2 and assigned 33% of the patients with a 3-year PFS of 35% vs. 82% for low risk group (P < 0·001). We have documented the impact of a few single genes added to IPI for assignment in new drug trials.

Tremblay CS, Brown FC, Collett M, et al.
Loss-of-function mutations of Dynamin 2 promote T-ALL by enhancing IL-7 signalling.
Leukemia. 2016; 30(10):1993-2001 [PubMed] Related Publications
Mutations in the DYNAMIN2 (DNM2) gene are frequently detected in human acute T-cell lymphoblastic leukemia (T-ALL), although the mechanisms linking these mutations to disease pathogenesis remain unknown. Using an ENU-based forward genetic screen for mice with erythroid phenotypes, we identified a heterozygous mouse line carrying a mutation in the GTPase domain of Dnm2 (Dnm2

Jiang CY, Yu JJ, Ruan Y, et al.
LIM domain only 2 over-expression in prostate stromal cells facilitates prostate cancer progression through paracrine of Interleukin-11.
Oncotarget. 2016; 7(18):26247-58 [PubMed] Free Access to Full Article Related Publications
Mechanisms of stromal-epithelial crosstalk are essential for Prostate cancer (PCa) tumorigenesis and progression. Peripheral zone of the prostate gland possesses a stronger inclination for PCa than transition zone. We previously found a variety of genes that differently expressed among different prostate stromal cells, including LIM domain only 2 (LMO2) which highly expressed in peripheral zone derived stromal cells (PZSCs) and PCa associated fibroblasts (CAFs) compared to transition zone derived stromal cells (TZSCs). Studies on its role in tumors have highlighted LMO2 as an oncogene. Herein, we aim to study the potential mechanisms of stromal LMO2 in promoting PCa progression. The in vitro cells co-culture and in vivo cells recombination revealed that LMO2 over-expressed prostate stromal cells could promote the proliferation and invasiveness of either prostate epithelial or cancer cells. Further protein array screening confirmed that stromal LMO2 stimulated the secretion of Interleukin-11 (IL-11), which could promote proliferation and invasiveness of PCa cells via IL-11 receptor α (IL11Rα) - STAT3 signaling. Moreover, stromal LMO2 over-expression could suppress miR-204-5p which was proven to be a negative regulator of IL-11 expression. Taken together, results of our study demonstrate that prostate stromal LMO2 is capable of stimulating IL-11 secretion and by which activates IL11Rα - STAT3 signaling in PCa cells and then facilitates PCa progression. These results may make stromal LMO2 responsible for zonal characteristic of PCa and as a target for PCa microenvironment-targeted therapy.

Pitt SC, Hernandez RA, Nehs MA, et al.
Identification of Novel Oncogenic Mutations in Thyroid Cancer.
J Am Coll Surg. 2016; 222(6):1036-1043.e2 [PubMed] Related Publications
BACKGROUND: Thyroid cancer patients frequently have favorable outcomes. However, a small subset develops aggressive disease refractory to traditional treatments. Therefore, we sought to characterize oncogenic mutations in thyroid cancers to identify novel therapeutic targets that may benefit patients with advanced, refractory disease.
STUDY DESIGN: Data on 239 thyroid cancer specimens collected between January 2009 and September 2014 were obtained from the Dana Farber/Brigham and Women's Cancer Center. The tumors were analyzed with the OncoMap-4 or OncoPanel high-throughput genotyping platforms that survey up to 275 cancer genes and 91 introns for DNA rearrangement.
RESULTS: Of the 239 thyroid cancer specimens, 128 (54%) had oncogenic mutations detected. These 128 tumors had 351 different mutations detected in 129 oncogenes or tumor suppressors. Examination of the 128 specimens demonstrated that 55% (n = 70) had 1 oncogenic mutation, and 45% (n = 48) had more than 1 mutation. The 351 oncogenic mutations were in papillary (85%), follicular (4%), medullary (7%), and anaplastic (4%) thyroid cancers. Analysis revealed that 2.3% (n = 3 genes) of the somatic gene mutations were novel. These included AR (n = 1), MPL (n = 2), and EXT2 (n = 1), which were present in 4 different papillary thyroid cancer specimens. New mutations were found in an additional 13 genes known to have altered protein expression in thyroid cancer: BLM, CBL, CIITA, EP300, GSTM5, LMO2, PRAME, SBDS, SF1, TET2, TNFAIP3, XPO1, and ZRSR2.
CONCLUSIONS: This analysis revealed that several previously unreported oncogenic gene mutations exist in thyroid cancers and may be targets for the development of future therapies. Further investigation into the role of these genes is warranted.

Zhou S, Fatima S, Ma Z, et al.
Evaluating the Safety of Retroviral Vectors Based on Insertional Oncogene Activation and Blocked Differentiation in Cultured Thymocytes.
Mol Ther. 2016; 24(6):1090-1099 [PubMed] Free Access to Full Article Related Publications
Insertional oncogenesis due to retroviral (RV) vector integration has caused recurrent leukemia in multiple gene therapy trials, predominantly due to vector integration effects at the LMO2 locus. While currently available preclinical safety models have been used for evaluating vector safety, none have predicted or reproduced the recurrent LMO2 integrations seen in previous X-linked severe combined immunodeficiency (X-SCID) and Wiskott-Aldrich clinical gene therapy trials. We now describe a new assay for assessing vector safety that recapitulates naturally occurring insertions into Lmo2 and other T-cell proto-oncogenes leading to a preleukemic developmental arrest in primary murine thymocytes cultured in vitro. This assay was used to compare the relative oncogenic potential of a variety of gamma-RV and lentiviral vectors and to assess the risk conferred by various transcriptional elements contained in these genomes. Gamma-RV vectors that contained full viral long-terminal repeats were most prone to causing double negative 2 (DN2) arrest and led to repeated cases of Lmo2 pathway activation, while lentiviral vectors containing these same elements were significantly less prone to activate proto-oncogenes or cause DN2 arrest. This work provides a new preclinical assay that is especially relevant for assessing safety in SCID disorders and provides a new tool for designing safer RV vectors.

Zhao S, Dong X, Shen W, et al.
Machine learning-based classification of diffuse large B-cell lymphoma patients by eight gene expression profiles.
Cancer Med. 2016; 5(5):837-52 [PubMed] Free Access to Full Article Related Publications
Gene expression profiling (GEP) had divided the diffuse large B-cell lymphoma (DLBCL) into molecular subgroups: germinal center B-cell like (GCB), activated B-cell like (ABC), and unclassified (UC) subtype. However, this classification with prognostic significance was not applied into clinical practice since there were more than 1000 genes to detect and interpreting was difficult. To classify cancer samples validly, eight significant genes (MYBL1, LMO2, BCL6, MME, IRF4, NFKBIZ, PDE4B, and SLA) were selected in 414 patients treated with CHOP/R-CHOP chemotherapy from Gene Expression Omnibus (GEO) data sets. Cutoffs for each gene were obtained using receiver-operating characteristic curves (ROC) new model based on the support vector machine (SVM) estimated the probability of membership into one of two subgroups: GCB and Non-GCB (ABC and UC). Furtherly, multivariate analysis validated the model in another two cohorts including 855 cases in all. As a result, patients in the training and validated cohorts were stratified into two subgroups with 94.0%, 91.0%, and 94.4% concordance with GEP, respectively. Patients with Non-GCB subtype had significantly poorer outcomes than that with GCB subtype, which agreed with the prognostic power of GEP classification. Moreover, the similar prognosis received in the low (0-2) and high (3-5) IPI scores group demonstrated that the new model was independent of IPI as well as GEP method. In conclusion, our new model could stratify DLBCL patients with CHOP/R-CHOP regimen matching GEP subtypes effectively.

Jevremovic D, Roden AC, Ketterling RP, et al.
LMO2 Is a Specific Marker of T-Lymphoblastic Leukemia/Lymphoma.
Am J Clin Pathol. 2016; 145(2):180-90 [PubMed] Related Publications
OBJECTIVES: The diagnosis of T-lymphoblastic leukemia/lymphoma (T-ALL) involving the thymus can be difficult to establish since neoplastic T lymphoblasts show significant phenotypic overlap with both normal thymocytes and thymocytes from epithelial thymic neoplasms (thymomas). LIM Domain Only 2 (LMO2) gene translocations have been implicated in the pathogenesis of a small subset of T-ALLs, and LMO2 protein has recently been reported to be expressed in a large proportion of T-ALLs.
METHODS: In this study, we tested specificity of LMO2 for distinction between neoplastic and nonneoplastic T-precursor cells in thymus and bone marrow.
RESULTS: Our findings show that LMO2 is expressed in neoplastic lymphoblasts of T-ALL and is absent in thymocytes of normal thymuses or thymomas.
CONCLUSIONS: LMO2 is therefore a useful marker for immunophenotypic assessment of thymic neoplasms.

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