This gene encodes a member of the Abelson family of nonreceptor tyrosine protein kinases. The protein is highly similar to the c-abl oncogene 1 protein, including the tyrosine kinase, SH2 and SH3 domains, and it plays a role in cytoskeletal rearrangements through its C-terminal F-actin- and microtubule-binding sequences. This gene is expressed in both normal and tumor cells, and is involved in translocation with the ets variant 6 gene in leukemia. Multiple alternatively spliced transcript variants encoding different protein isoforms have been found for this gene. [provided by RefSeq, Nov 2009]
t(1;12)(q25;p13) in Leukaemia (AML & ALL) The ETV6 (TEL) gene is frequently rearranged to various translocation partners in human leukemias. In a small number of cases the ETV6 gene is translocated with the ABL2 gene. In a RT-PCR study of samples from 176 patients with acute lymphoblastic leukemia (Zhou et al, 2012) found 15 had ETV6 gene rearrangements and of these 2 were ETV6/ABL1 translocations.
BACKGROUND: Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is characterized by a gene-expression profile similar to that of BCR-ABL1-positive ALL, alterations of lymphoid transcription factor genes, and a poor outcome. The frequency and spectrum of genetic alterations in Ph-like ALL and its responsiveness to tyrosine kinase inhibition are undefined, especially in adolescents and adults. METHODS: We performed genomic profiling of 1725 patients with precursor B-cell ALL and detailed genomic analysis of 154 patients with Ph-like ALL. We examined the functional effects of fusion proteins and the efficacy of tyrosine kinase inhibitors in mouse pre-B cells and xenografts of human Ph-like ALL. RESULTS: Ph-like ALL increased in frequency from 10% among children with standard-risk ALL to 27% among young adults with ALL and was associated with a poor outcome. Kinase-activating alterations were identified in 91% of patients with Ph-like ALL; rearrangements involving ABL1, ABL2, CRLF2, CSF1R, EPOR, JAK2, NTRK3, PDGFRB, PTK2B, TSLP, or TYK2 and sequence mutations involving FLT3, IL7R, or SH2B3 were most common. Expression of ABL1, ABL2, CSF1R, JAK2, and PDGFRB fusions resulted in cytokine-independent proliferation and activation of phosphorylated STAT5. Cell lines and human leukemic cells expressing ABL1, ABL2, CSF1R, and PDGFRB fusions were sensitive in vitro to dasatinib, EPOR and JAK2 rearrangements were sensitive to ruxolitinib, and the ETV6-NTRK3 fusion was sensitive to crizotinib. CONCLUSIONS: Ph-like ALL was found to be characterized by a range of genomic alterations that activate a limited number of signaling pathways, all of which may be amenable to inhibition with approved tyrosine kinase inhibitors. Trials identifying Ph-like ALL are needed to assess whether adding tyrosine kinase inhibitors to current therapy will improve the survival of patients with this type of leukemia. (Funded by the American Lebanese Syrian Associated Charities and others.).
Qiang XF, Zhang ZW, Liu Q, et al. miR-20a promotes prostate cancer invasion and migration through targeting ABL2. J Cell Biochem. 2014; 115(7):1269-76 [PubMed] Related Publications
The aberrant expression of microRNAs (miRNAs) has been found in various types of cancer. The present study found miR-20a was significantly up-regulated in prostate cancer compared with normal prostate tissues. Patients with a higher miR-20a expression had a Gleason score of 7-10 and shorter survival time. The transwell and wound healing assays revealed that blocking expression of miR-20a by miR-20a ASO suppresses the invasion and migration of PC-3 and DU145 cells in vitro and also inhibits tumor growth in vivo. Furthermore, we identified miR-20a directly targets the ABL family non-receptor tyrosine kinases ABL2 and negatively regulates the phosphorylation of its downstream gene p190RhoGAP. Knockdown of ABL2 promoted cell invasion and migration and we identified miR-20a-induced cell invasion and migration can be rescued by ABL2. In conclusion, our findings show that miR-20a significantly contributes to the progression of prostate cancer by targeting ABL2.
The Abelson (c-Abl) proto-oncogene encodes a highly conserved nonreceptor protein tyrosine kinase that plays a role in cell proliferation, differentiation, apoptosis and cell adhesion. c-Abl represents a specific anti-cancer target in prostate cancer as aberrant activity of this kinase has been implicated in the stimulation of prostate cancer growth and progression. However, the mechanism of regulation of c-Abl is not known. Here we report that Abl kinases are regulated by a novel microRNA, miR-4723, in prostate cancer. Expression profiling of miR-4723 expression in a cohort of prostate cancer clinical specimens showed that miR-4723 expression is widely attenuated in prostate cancer. Low miR-4723 expression was significantly correlated with poor survival outcome and our analyses suggest that miR-4723 has significant potential as a disease biomarker for diagnosis and prognosis in prostate cancer. To evaluate the functional significance of decreased miR-4723 expression in prostate cancer, miR-4723 was overexpressed in prostate cancer cell lines followed by functional assays. miR-4723 overexpression led to significant decreases in cell growth, clonability, invasion and migration. Importantly, miR-4723 expression led to dramatic induction of apoptosis in prostate cancer cell lines suggesting that miR-4723 is a pro-apoptotic miRNA regulating prostate carcinogenesis. Analysis of putative miR-4723 targets showed that miR-4723 targets integrin alpha 3 and Methyl CpG binding protein in addition to Abl1 and Abl2 kinases. Further, we found that the expression of Abl kinase is inversely correlated with miR-4723 expression in prostate cancer clinical specimens. Also, Abl1 knockdown partially phenocopies miR-4723 reexpression in prostate cancer cells suggesting that Abl is a functionally relevant target of miR-4723 in prostate cancer. In conclusion, we have identified a novel microRNA that mediates regulation of Abl kinases in prostate cancer. This study suggests that miR-4723 may be an attractive target for therapeutic intervention in prostate cancer.
He M, Fan J, Jiang R, et al. Expression of DNMTs and genomic DNA methylation in gastric signet ring cell carcinoma. Mol Med Rep. 2013; 8(3):942-8 [PubMed] Related Publications
The aim of the present study was to investigate the protein expression of DNA methyltransferases (DNMTs) and genomic DNA methylation status of genomes in gastric signet ring cell carcinoma (SRC). Immunohistochemistry was performed to analyze DNMT expression and methylated DNA immunoprecipitation microarray (MeDIP‑chip) and MeDIP quantitative real‑time PCR (MeDIP‑qPCR) were performed to analyze the genomic DNA methylation status in gastric SRC tissue. An increase in DNMT1 and decrease in DNMT3A expression in SRC tissue was observed compared with matched non‑cancerous tissue. However, expression of other DNMTs, DNMT2, DNMT3B and DNMT3L, was not found to differ significantly between carcinoma and control. The MeDIP‑chip assay revealed that methylation of gene promoters and CpG islands in SRC was higher than those in matched control tissue. However, MeDIP‑qPCR analysis demonstrated that specific tumor‑related genes, including ABL2, FGF18, TRAF2, EGFL7 and RAB33A were aberrantly hypomethylated in SRC tissue. Results of the current study indicate that gastric SRC may produce complex patterns of aberrant DNA methylation and DNMT expression.
He H, Wu G, Liu H, et al. Low RIN1 expression in HCC is associated with tumor invasion and unfavorable prognosis. Am J Clin Pathol. 2013; 140(1):73-81 [PubMed] Related Publications
OBJECTIVES: To explore the association between the expression of Ras and Rab interactor 1 (RIN1) and the prognosis of hepatocellular carcinoma (HCC). METHODS: RIN1 expression was detected in paired HCC tissues by real-time polymerase chain reaction, Western blot analysis, and immunohistochemistry. Transfection was applied to analyze the RIN1 function. RESULTS: We found that expression of the RIN1 protein was downregulated in the HCC samples compared with the corresponding normal tissues. Downregulation of RIN1 expression was also associated with invasion and poor overall survival (OS). The results of our multivariate analysis indicated that the RIN1 status is a significant prognostic factor for OS. RIN1 overexpression also inhibited cell invasion in HepG2 cells. The expression between RIN1 and ABL2 may present a positive correlation. CONCLUSIONS: Our results demonstrate that RIN1 suppresses tumor invasion in HCC patients and that a poor prognosis for HCC is expected when RIN1 expression is downregulated.
Ross RW, Galsky MD, Scher HI, et al. A whole-blood RNA transcript-based prognostic model in men with castration-resistant prostate cancer: a prospective study. Lancet Oncol. 2012; 13(11):1105-13 [PubMed] Related Publications
BACKGROUND: Survival for patients with castration-resistant prostate cancer is highly variable. We assessed the effectiveness of a whole-blood RNA transcript-based model as a prognostic biomarker in castration-resistant prostate cancer. METHODS: Peripheral blood was prospectively collected from 62 men with castration-resistant prostate cancer on various treatment regimens who were enrolled in a training set at the Dana-Farber Cancer Institute (Boston, MA, USA) from August, 2006, to June, 2008, and from 140 patients with castration-resistant prostate cancer in a validation set from Memorial Sloan-Kettering Cancer Center (New York, NY, USA) from August, 2006, to February, 2009. A panel of 168 inflammation-related and prostate cancer-related genes was assessed with optimised quantitative PCR to assess biomarkers predictive of survival. FINDINGS: A six-gene model (consisting of ABL2, SEMA4D, ITGAL, and C1QA, TIMP1, CDKN1A) separated patients with castration-resistant prostate cancer into two risk groups: a low-risk group with a median survival of more than 34·9 months (median survival was not reached) and a high-risk group with a median survival of 7·8 months (95% CI 1·8-13·9; p<0·0001). The prognostic utility of the six-gene model was validated in an independent cohort. This model was associated with a significantly higher area under the curve compared with a clinicopathological model (0·90 [95% CI 0·78-0·96] vs 0·65 [0·52-0·78]; p=0·0067). INTERPRETATION: Transcriptional profiling of whole blood yields crucial prognostic information about men with castration-resistant prostate cancer. The six-gene model suggests possible dysregulation of the immune system, a finding that warrants further study. FUNDING: Source MDX.
The interaction between human papillomavirus (HPV) and host cells is not well understood. We investigate the early stage of HPV infections by global expression profiling in a cell model, in which HaCaT cells were transfected with HPV11, HPV16 or HPV45 genomes. We report the differential expression of genes not previously implicated in HPV biology, such as the PSG family and ANKRD1, and of genes implicated in the biology of other viruses, e.g. MX1, IFI44 and DDX60. Carcinogenesis-related genes, e.g. ABL2, MGLL and CYR61, were upregulated by high-risk HPV16 and -45. The integrative analysis revealed the suppression of DNA repair by HPV11 and -16, and downregulation of cytoskeleton genes by all HPV types. Various signalling pathways were affected by the HPVs: IL-2 by HPV11; JAK-STAT by HPV16; and TGF-β, NOTCH and tyrosine kinase signalling by HPV45. This study uncovered novel strategies employed by HPV to establish infection and promote uncontrolled growth.
Tumor progression is a complex, multistep process involving accumulation of genetic aberrations and alterations in gene expression patterns leading to uncontrolled cell division, invasion into surrounding tissue and finally dissemination and metastasis. We have previously shown that the Arg/Abl2 non-receptor tyrosine kinase acts downstream of the EGF receptor and Src tyrosine kinases to promote invadopodium function in breast cancer cells, thereby promoting their invasiveness. However, whether and how Arg contributes to tumor development and dissemination in vivo has never been investigated. Using a mouse xenograft model, we show that knocking down Arg in breast cancer cells leads to increased tumor cell proliferation and significantly enlarged tumor size. Despite having larger tumors, the Arg-knockdown (Arg KD) tumor-bearing mice exhibit significant reductions in tumor cell invasion, intravasation into blood vessels and spontaneous metastasis to lungs. Interestingly, we found that proliferation-associated genes in the Ras-MAPK (mitogen-activated protein kinase) pathway are upregulated in Arg KD breast cancer cells, as is Ras-MAPK signaling, while invasion-associated genes are significantly downregulated. These data suggest that Arg promotes tumor cell invasion and dissemination, while simultaneously inhibiting tumor growth. We propose that Arg acts as a switch in metastatic cancer cells that governs the decision to 'grow or go' (divide or invade).
Zhou MH, Gao L, Jing Y, et al. Detection of ETV6 gene rearrangements in adult acute lymphoblastic leukemia. Ann Hematol. 2012; 91(8):1235-43 [PubMed] Related Publications
ETV6 is an important hematopoietic regulatory factor and ETV6 gene rearrangement is involved in a wide variety of hematological malignancies. In this study, we sought to investigate the incidence of ETV6-associated fusion genes in B- and T-lineage acute lymphoblastic leukemia (ALL) by multiplex-nested reverse transcription-polymerase chain reaction (RT-PCR) in 176 adult ALL patients. Total RNA was extracted from bone marrow samples of ALL patients including 136 B- and 40 T-lineage ALL, and ETV6 fusion genes were detected by multiplex-nested RT-PCR. Changes of ETV6 fusion gene mRNA transcript levels were examined by real-time RT-PCR. We detected a total of 15 ETV6 gene rearrangements with a positive rate of 8.5%, involving seven ETV6-associated fusion genes in 13 B-ALL (13/136, 9.6%) and 2 T-ALL patients (2/40, 5.0%). ETV6-RUNX1 were observed in six cases (3.4%), ETV6-JAK2 in three cases (1.7%), ETV6-ABL1 in two cases (1.1%), and ETV6-ABL2, ETV6-NCOA2, ETV6-SYK, and PAX5-ETV6 each in one case (0.6%). ETV6-JAK2 was found in both B-ALL and T-ALL patients. Furthermore, real-time quantitative RT-PCR assays showed that the ETV6-RUNX1 mRNA transcript levels decreased during conventional chemotherapy or hematopoietic stem cell transplantation. This study shows that multiplex-nested RT-PCR is an effective and accurate tool to identify ETV6 rearrangements in adult ALL, which provides some clues into the diagnosis and prognosis of ALL but also molecular markers for the detection of minimal residual disease in adult ALL.
Behbahani TE, Thierse C, Baumann C, et al. Tyrosine kinase expression profile in clear cell renal cell carcinoma. World J Urol. 2012; 30(4):559-65 [PubMed] Related Publications
PURPOSE: To profile different tyrosine kinase (TK) expression patterns in clear cell renal carcinoma (ccRCC). METHODS: We analysed mRNA expression levels of 89 receptor and non-receptor TK in corresponding cancer and normal renal tissue from 5 patients with ccRCC using the TaqMan Low-Density Array technology. In order to confirm aberrant TK expressions, a subsequent analysis of 25 ccRCC and corresponding normal renal tissues was performed, applying quantitative real-time PCR. To confirm mRNA expression levels on protein level, we studied ERBB4 and HCK using immunohistochemistry. RESULTS: A total of 12 TK were significantly upregulated in ccRCC (ABL2, FLT1, BTK, HCK, JAK3, CSF1R, MET, JAK1, MATK, PTPRC, FYN and CSK), coherently 7 TK demonstrated a down-regulation (ERBB4, PDGFRA, NRTK3, SYK, ERBB2, FGFR3 and PTK7). These findings were validated by the utilization of RT-PCR for ABL2, FLT1 BTK, HCK, JAK3, CSF1R, MET, JAK1, MATK and vice versa for ERBB4 and PDGFRA. Immunohistochemistry revealed ERBB4 expression to be significantly lower in ccRCC in comparison to papillary RCC, chromophobe RCC, renal oncocytoma and normal renal tissue (P < 0.001). HCK protein expression was reduced in ccRCC in contrast to papillary RCC (P < 0.001) or oncocytoma (P = 0.023), but similar to chromphobe RCC (P = 0.470), sarcomatoid RCC (P = 0.754) and normal renal tissue (P = 0.083). Neither ERBB4 nor HCK were correlated (P > 0.05) with clinical-pathological parameters. CONCLUSION: TK constitute valuable targets for pharmaceutical anti-cancer therapy. ERBB4 and HCK depict significantly lower expression levels in renal cancer tissues.
Somatic genetic alterations in cancers have been linked with response to targeted therapeutics by creation of specific dependency on activated oncogenic signaling pathways. However, no tools currently exist to systematically connect such genetic lesions to therapeutic vulnerability. We have therefore developed a genomics approach to identify lesions associated with therapeutically relevant oncogene dependency. Using integrated genomic profiling, we have demonstrated that the genomes of a large panel of human non-small cell lung cancer (NSCLC) cell lines are highly representative of those of primary NSCLC tumors. Using cell-based compound screening coupled with diverse computational approaches to integrate orthogonal genomic and biochemical data sets, we identified molecular and genomic predictors of therapeutic response to clinically relevant compounds. Using this approach, we showed that v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations confer enhanced Hsp90 dependency and validated this finding in mice with KRAS-driven lung adenocarcinoma, as these mice exhibited dramatic tumor regression when treated with an Hsp90 inhibitor. In addition, we found that cells with copy number enhancement of v-abl Abelson murine leukemia viral oncogene homolog 2 (ABL2) and ephrin receptor kinase and v-src sarcoma (Schmidt-Ruppin A-2) viral oncogene homolog (avian) (SRC) kinase family genes were exquisitely sensitive to treatment with the SRC/ABL inhibitor dasatinib, both in vitro and when it xenografted into mice. Thus, genomically annotated cell-line collections may help translate cancer genomics information into clinical practice by defining critical pathway dependencies amenable to therapeutic inhibition.
Kusumawidjaja G, Kayed H, Giese N, et al. Basic transcription factor 3 (BTF3) regulates transcription of tumor-associated genes in pancreatic cancer cells. Cancer Biol Ther. 2007; 6(3):367-76 [PubMed] Related Publications
Basic transcription factor 3 (BTF3) acts as a transcription factor and modulator of apoptosis, and is differentially expressed in colorectal cancer and glioblastomas. In the present study, the expression of BTF3, as well as its role in apoptosis and gene transcription, was analyzed in pancreatic ductal adenocarcinoma (PDAC). QRT-PCR, immunohistochemistry, immunoblotting, and immunofluorescence analyses were carried out to investigate BTF3 mRNA/protein expression and localization. BTF3 silencing in pancreatic cancer cells was performed using specific siRNA molecules. Functional analyses were carried out using cell growth assays, apoptosis assays, and DNA array analysis. BTF3 and BTF3a exhibited 1.3-fold and 4.6-fold increased median mRNA levels in PDAC tissues, compared to normal pancreatic tissues. BTF3 localized mainly in the cytoplasm and nuclei of tubular complexes and pancreatic cancer cells. Pancreatic cancer cell lines expressed the mRNA and protein of BTF3a (27 kDa) and BTF3b (22 kDa) isoforms. BTF3 silencing using specific siRNA molecules did not influence apoptosis induced by chemotherapy or radiotherapy. In contrast, BTF3 silencing resulted in down-regulation of several cancer-associated genes, including EPHB2, ABL2, HPSE2 and ATM, and up-regulation of KRAG, RRAS2, NFkappa-B, MRVI1, MADCAM1 and others. In conclusion, BTF3 is overexpressed in PDAC, where it acts as a transcriptional regulator rather than a direct modulator of apoptosis.
Chronic myeloid leukemia (CML) is a hematopoietic stem cell disease with distinct biological and clinical features. The biologic basis of the stereotypical progression from chronic phase through accelerated phase to blast crisis is poorly understood. We used DNA microarrays to compare gene expression in 91 cases of CML in chronic (42 cases), accelerated (17 cases), and blast phases (32 cases). Three thousand genes were found to be significantly (P < 10(-10)) associated with phase of disease. A comparison of the gene signatures of chronic, accelerated, and blast phases suggest that the progression of chronic phase CML to advanced phase (accelerated and blast crisis) CML is a two-step rather than a three-step process, with new gene expression changes occurring early in accelerated phase before the accumulation of increased numbers of leukemia blast cells. Especially noteworthy and potentially significant in the progression program were the deregulation of the WNT/beta-catenin pathway, the decreased expression of Jun B and Fos, alternative kinase deregulation, such as Arg (Abl2), and an increased expression of PRAME. Studies of CML patients who relapsed after initially successful treatment with imatinib demonstrated a gene expression pattern closely related to advanced phase disease. These studies point to specific gene pathways that might be exploited for both prognostic indicators as well as new targets for therapy.
De Keersmaecker K, Cools J Chronic myeloproliferative disorders: a tyrosine kinase tale. Leukemia. 2006; 20(2):200-5 [PubMed] Related Publications
Chronic myeloproliferative diseases (CMPDs) are characterized by the abnormal proliferation and survival of one or more myeloid cell types. The archetype of this class of hematological diseases is chronic myeloid leukemia (CML), characterized by the presence of the Philadelphia (Ph) chromosome, the result of t(9;22)(q34;q11), and the associated BCR-ABL1 oncogene. Some of the Ph-negative myeloproliferative diseases are characterized by other chromosomal translocations involving a variety of tyrosine kinase genes, including ABL1, ABL2, PDGFRA, PDGFRB, FGFR1, and JAK2. The majority of Ph-negative CMPDs, however, such as chronic eosinophilic leukemia, polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis are not characterized by the presence of recurrent chromosomal abnormalities. Recent studies have identified the FIP1L1-PDGFRA fusion gene, generated due to a small cryptic deletion on chromosome 4q12, and the activating V617F mutation in JAK2 in a significant fraction of Ph-negative CMPDs. These results show that abnormalities in tyrosine kinase genes are central to the molecular pathogenesis of CMPDs. Genome-wide screenings to identify novel tyrosine kinase abnormalities in CMPDs may contribute to further improvement of the diagnosis and the treatment of these diseases.
Cong XL, Li B, Yang RC, et al. Enhanced growth suppression of Philadephia1 leukemia cells by targeting bcr3/abl2 and VEGF through antisense strategy. Leukemia. 2005; 19(9):1517-24 [PubMed] Related Publications
An antisense strategy by targeting both bcr3/abl2 and VEGF was designed to suppress the growth of Philadephia1 leukemia cells in vitro and in vivo in mice. In vitro, although bcr3/abl2 or VEGF antisense oligodeoxyribonucleotides (AS-ODNs) alone was able to inhibit the proliferation of K562 cells, the combination of bcr3/abl2 and VEGF AS-ODNs produced an additive inhibitory effect on the growth of K562 cells and significantly enhanced the sensibility of K562 cells to apoptosis-inducing stimuli including STI571. In vivo, the nude mice xenografted with K562 cells received intratumoral injections of bcr3/abl2 and VEGF AS-ODNs showed a significant reduction in leukemia tumor size and microvessel density and an increase of apoptosis in the tumors when compared to the mice that received an individual agent. These results demonstrate that targeting both bcr3/abl2 and VEGF can result in an additive tumor-suppressive action and may represent an excellent strategy to augment the efficacy of chemotherapy in CML.
Okuda K, Oda A, Sato Y, et al. Signal transduction and cellular functions of the TEL/ARG oncoprotein. Leukemia. 2005; 19(4):603-10 [PubMed] Related Publications
The TEL/ARG oncogene is formed by t(1;12)(q25;p13) reciprocal translocation and is associated with human leukemia. We have previously demonstrated that the expression of TEL/ARG in Ba/F3 cells results in prolonged viability and hyper-responsiveness to IL-3. To determine the molecular mechanisms, a series of mutants of TEL/ARG were generated, and each cDNA was expressed in Ba/F3 or CHO cells. The PNT domain in TEL and K317 in ARG were essential for both signaling and biological effects. The SH3 domain in ARG was required for hyper-responsiveness to IL-3, but not for prolonged viability. The opposite was true for the SH2 domain in ARG. Mutation of Y314 in TEL, a putative GRB2-binding site, led to reduced viability, and loss of hyper-responsiveness to IL-3. All biological functions were profoundly impaired with deletion of the C-terminus in ARG, despite maintaining high levels of its kinase activity. When expressed in CHO cells, wild-type TEL/ARG induced the formation of fillopodia, in a fashion dependent on the C-terminal portion and intact kinase activity. Thus, these results suggest several critical domains within TEL/ARG necessary for function, and indicate that the signaling pathways necessary for viability, growth factor hyper-responsiveness and cytoskeletal reorganization are likely to be separate.
The identification of genes undergoing genetic or epigenetic alterations and contributing to the development of cancer is critical to our understanding of the molecular mechanisms of carcinogenesis. A new approach in identifying alterations of genes that might be relevant to the process of tumor development was used in this study by examining the gene expression profile in human lung cancer cells exposed to 5-aza-2'-deoxycytidine (5-aza-dC). A cDNA array analysis was carried out on 5-aza-dC-treated and untreated non small cell lung cancer (NSCLC) cell line NCI-H522. Sixteen and 14 genes were upregulated and downregulated, respectively, by 5-aza-dC treatment. Among them, downregulation of tyrosine protein kinase ABL2 (ABL2) gene and upregulation of hint/protein kinase C inhibitor 1 (Hint/PKCI-1), DVL1, TIMP-1, and TRP-1 genes were found in expanded observations in two or three of five 5-aza-dC-treated NSCLC cell lines. Among these genes, we found that cDNA transfer of Hint/PKCI-1 resulted in a significant in vitro growth inhibition in two cell lines exhibiting 5-aza-dC-induced upregulation of Hint/PKCI-1 and significantly reduced in vivo tumorigenicity of one NSCLC cell line. Hint/PKCI-1, which is the only other characterized human histidine triad (HIT) nucleotide-binding protein in addition to tumor-suppressor gene FHIT, might be involved in lung carcinogenesis.
The twenty-first century is beginning with a sharp turn in the field of cancer therapy. Molecular targeted therapies against specific oncogenic events are now possible. The BCR-ABL story represents a notable example of how research from the fields of cytogenetics, retroviral oncology, protein phosphorylation, and small molecule chemical inhibitors can lead to the development of a successful molecular targeted therapy. Imatinib mesylate (Gleevec, STI571, or CP57148B) is a direct inhibitor of ABL (ABL1), ARG (ABL2), KIT, and PDGFR tyrosine kinases. This drug has had a major impact on the treatment of chronic myelogenous leukemia (CML) as well as other blood neoplasias and solid tumors with etiologies based on activation of these tyrosine kinases. Analysis of CML patients resistant to BCR-ABL suppression by Imatinib mesylate coupled with the crystallographic structure of ABL complexed to this inhibitor have shown how structural mutations in ABL can circumvent an otherwise potent anticancer drug. The successes and limitations of Imatinib mesylate hold general lessons for the development of alternative molecular targeted therapies in oncology.
Okuda K, Sato Y, Sonoda Y, Griffin JD The TEL/ARG leukemia oncogene promotes viability and hyperresponsiveness to hematopoietic growth factors. Int J Hematol. 2004; 79(2):138-46 [PubMed] Related Publications
The TEL/ARG oncogene associated with acute myeloid leukemia is formed by the t(1;12)(q25;p13) reciprocal translocation, which fuses part of the TEL gene to the tyrosine kinase, c-ARG. In an effort to determine the biological effects and investigate signaling of the TEL/ARG fusion protein, multiple sublines of Ba/F3 cells were generated in which a TEL/ARG complementary DNA was expressed under the control of a tetracycline-inducible promoter. Treatment of these cells with doxycycline, a tetracycline analogue, rapidly induced expression of the TEL/ARG protein. TEL/ARG was heavily phosphorylated on tyrosine residues and was also found to rapidly induce tyrosine phosphorylation of multiple cellular proteins, including rasGAP, CBL, STAT5, PI3K, SHP2, Dok, and SHC. The Ba/F3-tet-TEL/ARG cells remained interleukin (IL)-3 dependent without doxycycline but with doxycycline displayed a marked reduction in cell death in the absence of IL-3. TEL/ ARG cells also displayed an enhanced proliferative response to IL-3 and to insulin-like growth factor 1. At least in Ba/F3 cells, although the growth rate was much lower compared to that with IL-3, TEL/ARG appeared to induce some cell proliferation as an immediate consequence. Nonetheless, the hyperresponsiveness to growth factors reported here is more likely to contribute to the pathogenesis of leukemia.
Zhang YP, Li YQ, Yang LJ, et al. [Clonal expansion of TCR Vbeta subfamily T cells induced by bcr3-abl2 peptide]. Zhonghua Xue Ye Xue Za Zhi. 2004; 25(2):95-9 [PubMed] Related Publications
OBJECTIVE: To investigate the clonal expansion of T cell receptor (TCR) Vbeta subfamily T cells from cord blood induced by bcr3-abl2 peptide in vitro. METHODS: T cells from 3 units of cord blood were amplified by anti-CD(3) monoclonal antibody (McAb) and IL-2 with or without synthetic b3a2 peptide. T cell specific cytotoxicity was analyzed by lactate dehydrogenase (LDH) assay, TCR Vbeta subfamilies by using reverse transcriptase-polymerase chain reaction (RT-PCR) and genescan technique. RESULTS: bcr3-abl2 peptide specific cytotoxicity T cells were successfully induced from the 3 units of cord blood by synthetic b3a2 peptide. Compared with that in CD(3) McAb induced cells, distribution pattern of TCR Vbeta repertoire was different in T cells induced with b3a2 peptide. Oligoclonal and oligoclonal tendency TCR Vbeta subfamily T cells could be identified in cord blood T cells induced by b3a2 peptide in 1 or 2 weeks, whereas those induced by anti-CD(3) McAb and IL-2 were mostly polyclonal. CONCLUSION: The cytotoxicity T cells with anti-CML specificity could be induced by b3a2 peptide. The specific anti-CML cytotoxicity may be derived from the clonal expansion TCR Vbeta subfamily T cells.
Liu LX, Jiang HC, Liu ZH, et al. Gene expression profiles of hepatoma cell line BEL-7402. Hepatogastroenterology. 2003 Sep-Oct; 50(53):1496-501 [PubMed] Related Publications
BACKGROUND/AIMS: To investigate the gene expression of cancer related genes in hepatoma cell line BEL-7402 through the usage of Atlas Human Cancer Array with 588 well-characterized human genes related with cancer biology. METHODOLOGY: Hybridization of cDNA membrane was performed with 32P-labeled cDNA probes synthesized from RNA isolated from Human hepatoma cell line BEL-7402 and non-cirrhotic normal liver which was liver transplantation donor. Bioinformatics was used to analyze the result. The reverse transcription polymerase chain reaction of 24 pairs of specimens and northern blot of 4 pairs of specimens were used to confirm the expression pattern of some genes identified by Atlas arrays hybridization. RESULTS: The differential expression cell cycle/growth regulator in hepatoma cell line BEL-7402 showed a stronger tendency toward cell proliferation with up-regulation of E2F-3 and TFDP-2. The anti-apoptotic factors such as Akt-1 were up-regulated. Whereas the promotive genes of apoptosis were down-regulated, such as BAK and caspase-3. Besides this, some genes were up-regulated, such as Integrin beta 8, DNA-PK, CSPCP, cyclin C etc. A number of genes were down-regulated, which included LAR, ABL2, SKY, TDGF1 etc. In general, expression of the cancer progression genes were up-regulated, while expression of anti-cancer progression genes were down-regulated. The results of reverse transcription polymerase chain reaction of 24 pairs of specimens and Northern Blot of 4 pairs of specimens were consistent with the expression pattern of some genes identified by Atals arrays hybridization. CONCLUSIONS: Investigation of gene expression profile of hepatoma cell line BEL-7402 should help to disclose the molecular mechanism of the onset, progression and prognosis of hepatocellular carcinoma. The quick and high-throughout method of profiling gene expression by cDNA array provides us with an overview of key factors that may be involved in hepatocellular carcinoma, and may find the clue to the study of hepatocellular carcinoma carcinogenesis and molecular targets of diagnosis and therapy.
Liu LX, Liu ZH, Jiang HC, et al. Gene expression profiles of hepatoma cell line HLE. World J Gastroenterol. 2003; 9(4):683-7 [PubMed] Related Publications
AIM: To investigate the global gene expression of cancer related genes in hepatoma cell line HLE using Atlas Human Cancer Array membranes with 588 well-characterized human genes related with cancer and tumor biology. METHODS: Hybridization of cDNA blotting membrane was performed with (32)P-labeled cDNA probes synthesized from RNA isolated from Human hepatoma cell line HLE and non-cirrhotic normal liver which was liver transplantation donor. AtlasImage, a software specific to array, was used to analyze the result. The expression pattern of some genes identified by Atlas arrays hybridization was confirmed by reverse transcription polymerase chain reaction (RT-PCR) in 24 pairs of specimens and Northern blot of 4 pairs of specimens. RESULTS: The differential expression of cell cycle/growth regulator in hepatocellular carcinoma (HCC) showed a stronger tendency toward cell proliferation with more than 1.5-fold up-regulation of Cyclin C, ERK5, ERK6, E2F-3, TFDP-2 and CK4. The anti-apoptotic factors such as Akt-1 were up-regulated, whereas the promotive genes of apoptosis such as ABL2 were down-regulated. Among oncogene/tumors suppressors, SKY was down-regulated. Some genes such as Integrin beta 8, Integrin beta 7, DNA-PK, CSPCP, byglycan, Tenacin and DNA Topo were up-regulated. A number of genes, including LAR, MEK1, eps15, TDGF1, ARHGDIA were down-regulated. In general, expression of the cancer progression genes was up-regulated, while expression of anti-cancer progression genes was down-regulated. These differentially expressed genes tested with RT-PCR were in consistent with cDNA array findings. CONCLUSION: Investigation of these genes in HCC is helpful in disclosing molecular mechanism of pathogenesis and progression of HCC. For the first time few genes were discovered in HCC. Further study is required for the precise relationship between the altered genes and their correlation with the pathogenesis of HCC.
de Vos S, Hofmann WK, Grogan TM, et al. Gene expression profile of serial samples of transformed B-cell lymphomas. Lab Invest. 2003; 83(2):271-85 [PubMed] Related Publications
Follicular lymphoma (FL) is characterized by a continuous rate of relapse and transformation to a high-grade lymphoma, usually diffuse large B-cell lymphoma (DLBCL), associated with a dismal prognosis and a poor response to conventional chemotherapy. The progression of indolent to aggressive FL is accompanied by the successive accumulation of recurrent chromosomal defects, but the resultant alterations of gene expression are largely unknown. To expand the understanding of the pathogenesis of FL transformation, we initially performed oligonucleotide microarray analyses using Affymetrix HuFL chips on five cases with matched snap-frozen lymph nodes before and after transformation. Expression data were analyzed using the Affymetrix Microarray Suite 4.0 and Genespring 4.0. Thirty-six genes with increased expression and 66 genes with decreased expression associated with transformation were identified and functionally classified. The expression of differentially expressed genes was confirmed by real-time quantitative RT-PCR (QRT-PCR) using a total of seven matched pairs and an additional five FL and five unrelated DLBCL. In addition, selected genes were further analyzed by QRT-PCR or immunohistochemistry using a large, unrelated series of FL (grades 1 to 3) as well as transformed and de novo DLBCL (total of 51 samples). The microarray results correlated with the protein expression data obtained from samples at the time of initial diagnosis and transformation. Furthermore, the expression of 25 candidate genes was evaluated by QRT-PCR with a 78% confirmation rate. Some of the identified genes, such as nucleobindin, interferon regulatory factor 4, and tissue inhibitor of metalloproteinases 1, are already known to be associated with high-grade non-Hodgkin's lymphoma. Novel candidate genes with confirmed increased and decreased expression in transformed DLBCL include ABL2 and NEK2, and PDCD1 and VDUP1, respectively. In summary, this study shows that transformation of FL to DLBCL is associated with a distinct set of differentially expressed genes of potential functional importance.
Griesinger F, Janke A, Podleschny M, Bohlander SK Identification of an ETV6-ABL2 fusion transcript in combination with an ETV6 point mutation in a T-cell acute lymphoblastic leukaemia cell line. Br J Haematol. 2002; 119(2):454-8 [PubMed] Related Publications
ETV6, a member of the Ets family of transcription factors, is frequently rearranged to various translocation partners in human leukaemias. We previously described a CD3+/TCRalpha/beta+ mature T-cell acute lymphoblastic leukaemia (T-ALL) cell line, MT-ALL, carrying a t(1;10;12)(q25; p13;p13) with cytokine-inducible lineage switch into the myeloid lineage. Using reverse transcription polymerase chain reaction with primers complementary to ETV6 and ABL2, two ETV6-ABL2 fusion transcripts were identified in MT-ALL which resulted from alternative splicing of an ABL2 exon. The fusion transcripts code for putative ETV6-ABL2 fusion proteins containing the pointed domain of ETV6 and almost the complete ABL2 protein, including the SH2, SH3 domains and the protein tyrosine kinase domain (PTK). Identical ETV6-ABL2 fusion transcripts have been reported in an acute myeloid leukaemia (AML) M3 cell line, carrying both a t(15;17)(q22;q21) and a t(1;12)(q25;p13) with unusual inducible differentiation to eosinophils, and in a patient with AML-M4eo. Interestingly, the non-rearranged allele of ETV6 in the MT-ALL cell line carries an arginine to histidine (R399H) mutation which affects a conserved amino acid in the ets DNA binding domain.
Liu LX, Liu ZH, Jiang HC, et al. Profiling of differentially expressed genes in human gastric carcinoma by cDNA expression array. World J Gastroenterol. 2002; 8(4):580-5 [PubMed] Related Publications
AIM: To investigate the expression of cancer related genes in gastric carcinoma (GC) through the use of Atlas Human Cancer Array membranes with 588 well-characterized human genes related to cancer and tumor biology. METHODS: Hybridization of cDNA blotting membrane was performed with (32)P-labeled cDNA probes synthesized from RNA isolated from gastric carcinoma and adjacent noncancerous gastric epithelial tissue. AtlasImage, which is a software specific to array, was used to analyze the result. RESULTS: The differentially expression cell cycle/growth regulator in GC showed a stronger tendency toward cell proliferation with 2.7-fold up-regulation of CK1. The promoter genes of apoptosis were down-regulated, including caspase-8 precursor, caspase-9 and caspase-10. Among the oncogene/tumor suppressor genes, ABL2 was down-regulated. In addition, some genes were up-regulated, including matrix metalloproteinse 2(MMP-2), MMP-16(MT3-MMP), SKY, CD9 and semaphorin V. A number of genes were down-regulated, including neuroendocrine-dlg (NE-dlg), retinoic acid receptor gamma and tumor suppressor DCC colorectal. In general, The expression of the cancer progression genes were up-regulated, while the expression of anti-cancer progression genes were down-regulated. CONCLUSION: Investigation of these genes should help to disclose the molecular mechanism of the onset, progression and prognosis of GC. Several genes are reported herein to be altered in GC for the first time. The quick and high-throughout method of profiling gene expression by cDNA array provides us with an overview of key factors that may involved in GC, and may aid the study of GC carcinogenesis and provide molecular targets for diagnosis and therapy. The precise relationship between the altered genes and gastric carcinogenesis is a matter for further investigation.
Crnogorac-Jurcevic T, Efthimiou E, Nielsen T, et al. Expression profiling of microdissected pancreatic adenocarcinomas. Oncogene. 2002; 21(29):4587-94 [PubMed] Related Publications
Pancreatic ductal adenocarcinoma is characterized by a paucity of neoplastic cells embedded in a densely desmoplastic stroma. Therefore, laser capture microdissection was performed to obtain homogeneous populations of normal and neoplastic ductal cells. These were subjected to a comparative study of gene expression utilizing human cDNA arrays. A variety of dysregulated genes were identified, comprising cell cycle and growth regulators, invasion regulators, signalling and developmental molecules. In addition to genes already found to be overexpressed in pancreatic cancer, such as TIMP1, MMP7, CD59, rhoC and NDKA, we present evidence to implicate genes which have not previously been reported in this tumour type. These include the overexpressed genes ABL2, Notch4 and SOD1, as well as XRCC1, a DNA repair gene whose transcript was found downregulated. Quantitative real-time RT-PCR (QRT-PCR) was employed to confirm differential expression of ABL2, Notch4 and SOD1 and immunohistochemical analysis was used to verify decreased protein expression of XRCC1 using a custom-built pancreatic tissue array. Combining microarray-derived gene expression profiles of pure pancreatic cell populations, QRT-PCR and pancreas-specific tissue arrays therefore proved to be highly informative in elucidating the molecular pathology of this highly malignant tumour type.
Yagasaki F, Wakao D, Yokoyama Y, et al. Fusion of ETV6 to fibroblast growth factor receptor 3 in peripheral T-cell lymphoma with a t(4;12)(p16;p13) chromosomal translocation. Cancer Res. 2001; 61(23):8371-4 [PubMed] Related Publications
Fusions of the ETV6/TEL gene to receptor or protein tyrosine kinases (TKs), such as PDGFRbeta, JAK2, ABL, ABL2, TRKC, and Syk, have been reported in various hematological malignancies. Expression of the resultant chimeric proteins is believed to lead to constitutive TK activity through activation by the helix-loop-helix (HLH) domain of ETV6. We identified a novel ETV6 partner gene, fibroblast growth factor receptor 3 (FGFR3), in a patient with peripheral T-cell lymphoma (PTCL) with a t(4;12)(p16;p13) translocation. The ETV6-FGFR3 transcript showed a fusion of exon 5 of ETV6 to exon 10 of FGFR3, resulting in an open reading frame for a chimeric protein consisting of the HLH domain of ETV6 and the TK domains of FGFR3. This is the first report of ETV6 and FGFR3 involvement in PTCL.
Okuda K, Weisberg E, Gilliland DG, Griffin JD ARG tyrosine kinase activity is inhibited by STI571. Blood. 2001; 97(8):2440-8 [PubMed] Related Publications
The tyrosine kinase inhibitor STI571 inhibits BCR/ABL and induces hematologic remission in most patients with chronic myeloid leukemia. In addition to BCR/ABL, STI571 also inhibits v-Abl, TEL/ABL, the native platelet-derived growth factor (PDGF)beta receptor, and c-KIT, but it does not inhibit SRC family kinases, c-FMS, FLT3, the epidermal growth factor receptor, or multiple other tyrosine kinases. ARG is a widely expressed tyrosine kinase that shares substantial sequence identity with c-ABL in the kinase domain and cooperates with ABL to regulate neurulation in the developing mouse embryo. As described here, ARG has recently been implicated in the pathogenesis of leukemia as a fusion partner of TEL. A TEL/ARG fusion was constructed to determine whether ARG can be inhibited by STI571. When expressed in the factor-dependent murine hematopoietic cell line Ba/F3, the TEL/ARG protein was heavily phosphorylated on tyrosine, increased tyrosine phosphorylation of multiple cellular proteins, and induced factor-independent proliferation. The effects of STI571 on Ba/F3 cells transformed with BCR/ABL, TEL/ABL, TEL/PDGFbetaR, or TEL/ARG were then compared. STI571 inhibited tyrosine phosphorylation and cell growth of Ba/F3 cells expressing BCR/ABL, TEL/ABL, TEL/PDGFbetaR, and TEL/ARG with an IC(50) of approximately 0.5 microM in each case, but it had no effect on untransformed Ba/F3 cells growing in IL-3 or on Ba/F3 cells transformed by TEL/JAK2. Culture of TEL/ARG-transfected Ba/F3 cells with IL-3 completely prevented STI571-induced apoptosis in these cells, similar to what has been observed with BCR/ABL- or TEL/ABL-transformed cells. These results indicate that ARG is a target of the small molecule, tyrosine kinase inhibitor STI571.
Van Limbergen H, Beverloo HB, van Drunen E, et al. Molecular cytogenetic and clinical findings in ETV6/ABL1-positive leukemia. Genes Chromosomes Cancer. 2001; 30(3):274-82 [PubMed] Related Publications
Rearrangements of 12p, resulting from deletions or translocations, are common findings in hematologic malignancies. In many cases, these rearrangements target the ETV6 gene (previously called TEL) located at 12p13. Various partner genes have been implicated in the formation of fusion genes with ETV6. These include PDGFRB, JAK2, NTRK3, ABL2, and ABL1, each of which encodes for proteins with tyrosine kinase activity. To date, ETV6/ABL1 transcripts have been detected in only four patients with a leukemic disorder. Here, we describe one adult with chronic myeloid leukemia and a child with T-cell acute lymphocytic leukemia with ETV6/ABL1. Molecular cytogenetic analysis confirmed that formation of an ETV6/ABL1 fusion in these patients required at least three chromosomal breaks and showed that each of these translocations is the result of a complex chromosomal rearrangement. Molecular analysis showed the presence of two fusion transcripts in both patients as the result of alternative splicing, questioning the suggested role of these transcripts in the lineage specificity. Clinical findings of these patients were compared to those of previously reported cases, and the possible clinical and biological similarities between ETV6/ABL1 and other fusion genes leading to increased tyrosine kinase activity are discussed.
Iijima Y, Ito T, Oikawa T, et al. A new ETV6/TEL partner gene, ARG (ABL-related gene or ABL2), identified in an AML-M3 cell line with a t(1;12)(q25;p13) translocation. Blood. 2000; 95(6):2126-31 [PubMed] Related Publications
The ETV6/TEL gene has been reported to fuse to PDGFRbetab MDS1/EVI1, BTL, ACS2, STL, JAK2, ABL, CDX2, TRKC, AML1, and MN1. Among them, PDGFRbeta, ABL, JAK2, and TRKC are tyrosine kinases (TK). We identified a novel ETV6 partner gene, ARG (ABL-related gene or ABL2), another TK gene in a cell line established from a patient with acute myelogenous leukemia (AML-M3) with a t(15;17)(q22;q11.2) and a t(1;12)(q25;p13), which has the remarkable feature to differentiate to mature eosinophils in culture with all-trans retinoic acid and cytokines. The ETV6/ARG transcripts consisted of exon 1 to 5 of ETV6 and the 3' portion of ARG starting from exon 1B or exon 2, resulting in an open reading frame for a fusion protein consisting of the entire PNT oligomerization domain of ETV6 and all of the functional domains of ARG including the TK domain. This is the same protein structure as identified in the other ETV6 TK fusion proteins. The reciprocal ARG/ETV6 transcript was not expressed, and the normal ETV6 allele was not deleted or rearranged. Although the ABL is known to be involved in various human malignancies, ARG has not been involved in human malignancies despite its high homology to ABL. Thus, this is the first report showing involvement of ARG in human leukemia. The ETV6/ARG protein may be involved in the unique differentiation capacity of this cell line. (Blood. 2000;95:2126-2131)