The Importance of WT1 in Leukemia

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4645-4645
Author(s):  
Sony Pandey ◽  
Mustafa Moazam ◽  
Kurtis Eisermann ◽  
Jeffrey Hord ◽  
Gail Fraizer ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Tumor Suppressor Gene ◽  
Cell Lines ◽  
Target Genes ◽  
Suppressor Gene ◽  
Genetic Alterations ◽  
Prognostic Impact ◽  
Mrna Levels ◽  
Wt1 Gene ◽  
Vegf Expression

Abstract Abstract 4645 Acute leukemias collectively comprise the most common group of malignancies in the pediatric age group. Increasingly, therapeutic approach and prognosis are influenced by leukemia-specific cytogenetic abnormalities and genetic alterations, thus highlighting the importance of identifying novel prognostic markers. The Wilms’ tumor suppressor gene WT1 is expressed in leukemic blasts and is found to be mutated in approximately 10 percent of leukemia cases. Although it is unclear whether WT1 acts as an oncogene or a tumor suppressor gene in leukemia, it is known to regulate genes involved in cancer progression, including the angiogenic and mitogenic factor, VEGF. Previous studies in kidney and prostate cell lines identified potential WT1 binding sites on the VEGF-A gene promoter and demonstrated that WT1 transcriptionally regulated VEGF expression. Thus, we hypothesized that WT1 transcriptionally regulates VEGF expression in leukemia. To examine WT1 and VEGF expression patterns in pediatric Acute Lymphocytic Leukemia (ALL), Acute Myeloid Leukemia (AML) and non-neoplastic bone marrow samples, we performed quantitative real time PCR. It was observed that WT1 and VEGF expression varied depending upon the type and sub-type of leukemia. Furthermore, to understand the significance of WT1 expression, we over-expressed GFP- WT1 in Molt-4 cells (T-ALL), HL-60 (AML) and K562 cells (CML) and then quantified mRNA levels of VEGF and the potential WT1 target genes CCNA1 and JAG. The results showed that WT1 levels induced variable expression of VEGF, CCNA1 and JAG in these different leukemic cell lines. Elevated expression of WT1 genes harboring mutations of the zinc finger (ZF) DNA binding domain has also been described in a subset of leukemias and has been associated with a poor prognosis. We therefore screened pediatric acute leukemia samples for novel ZF mutations that would abrogate its ability to regulate VEGF and other target genes. Conversely, a well described SNP rs16754 (in exon 7 of the WT1 gene) identified as a good prognostic marker in Cytogenetically Normal AML (CN-AML) was observed in our pediatric population as both homozygous and heterozygous variants of the WT1 gene. Our long term goal is to determine the molecular basis of the prognostic impact associated with variant WT1 expression in pediatric and adult leukemias. Disclosures: No relevant conflicts of interest to declare.

scholarly journals TNFAIP3 (A20) is a tumor suppressor gene in Hodgkin lymphoma and primary mediastinal B cell lymphoma

2009 ◽  
Vol 206 (5) ◽  
pp. 981-989 ◽  
Author(s):  
Roland Schmitz ◽  
Martin-Leo Hansmann ◽  
Verena Bohle ◽  
Jose Ignacio Martin-Subero ◽  
Sylvia Hartmann ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
B Cell ◽  
Hodgkin Lymphoma ◽  
Tumor Suppressor Gene ◽  
Cell Lines ◽  
Target Genes ◽  
Zinc Finger Protein ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Suppressor Gene

Proliferation and survival of Hodgkin and Reed/Sternberg (HRS) cells, the malignant cells of classical Hodgkin lymphoma (cHL), are dependent on constitutive activation of nuclear factor κB (NF-κB). NF-κB activation through various stimuli is negatively regulated by the zinc finger protein A20. To determine whether A20 contributes to the pathogenesis of cHL, we sequenced TNFAIP3, encoding A20, in HL cell lines and laser-microdissected HRS cells from cHL biopsies. We detected somatic mutations in 16 out of 36 cHLs (44%), including missense mutations in 2 out of 16 Epstein-Barr virus–positive (EBV+) cHLs and a missense mutation, nonsense mutations, and frameshift-causing insertions or deletions in 14 out of 20 EBV− cHLs. In most mutated cases, both TNFAIP3 alleles were inactivated, including frequent chromosomal deletions of TNFAIP3. Reconstitution of wild-type TNFAIP3 in A20-deficient cHL cell lines revealed a significant decrease in transcripts of selected NF-κB target genes and caused cytotoxicity. Extending the mutation analysis to primary mediastinal B cell lymphoma (PMBL), another lymphoma with constitutive NF-κB activity, revealed destructive mutations in 5 out of 14 PMBLs (36%). This report identifies TNFAIP3 (A20), a key regulator of NF-κB activity, as a novel tumor suppressor gene in cHL and PMBL. The significantly higher frequency of TNFAIP3 mutations in EBV− than EBV+ cHL suggests complementing functions of TNFAIP3 inactivation and EBV infection in cHL pathogenesis.

4q loss is potentially an important genetic event in MM tumorigenesis: identification of a tumor suppressor gene regulated by promoter methylation at 4q13.3, platelet factor 4

Blood ◽  
2006 ◽  
Vol 109 (5) ◽  
pp. 2089-2099 ◽  
Author(s):  
Suk Hang Cheng ◽  
Margaret H. L. Ng ◽  
Kin Mang Lau ◽  
Herman S. Y. Liu ◽  
Joyce C. W. Chan ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Tumor Suppressor Gene ◽  
Cell Lines ◽  
Plasma Cells ◽  
Suppressor Gene ◽  
Genetic Alterations ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Genetic Event ◽  
Chromosomal Imbalances

Abstract In this study, we have elucidated the chromosomal imbalances in the multistep pathogenesis and delineated several critical tumor suppressor gene (TSG) loci in multiple myeloma (MM). By using comparative genomic hybridization, allelotyping, and multicolor interphase fluorescence in situ hybridization, 5 MM cell lines and bone marrow CD138+ plasma cells from 88 Chinese patients with monoclonal gammopathy of undetermined significance (MGUS) and early and advanced stages of MM were investigated. In all MGUS and MM samples, chromosome copy number abnormalities were detected. A higher number of chromosomal imbalances and specific genetic alterations are involved in MGUS to MM transition (−6q, +3p, and +1p) and MM progression (+2p and +9q). In addition to −13q, we first found high frequencies (42% to 46%) of −4q involving high percentages (70% to 74%) of clonal plasma cells in both MGUS and MM, suggesting that inactivation of TSG in this region is also a potentially critical genetic event in MM tumorigenesis. By high-resolution allelotyping, we defined a common deletion region on 4q13.3 and found that a candidate TSG, platelet factor 4, was frequently silenced by promoter hypermethylation in MM (15 of 28) and MM cell lines (5 of 5). These data have opened up a new approach in the molecular targeting therapy and provide novel insights into MM tumorigenesis.

Mutations in tumor suppressor gene, FBXW7, are associated with carboplatin resistance in endometrial cancer cell lines

2015 ◽  
Vol 139 (1) ◽  
pp. 194 ◽  
Author(s):  
Alexandre Buckley de Meritens ◽  
Ayesha Joshi ◽  
Christopher Miller ◽  
Lora Hedrick Ellenson ◽  
Divya Gupta
Keyword(s):  
Endometrial Cancer ◽  
Tumor Suppressor ◽  
Tumor Suppressor Gene ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Suppressor Gene ◽  
Endometrial Cancer Cell

scholarly journals Nkx2.5 Functions as a Conditional Tumor Suppressor Gene in Colorectal Cancer Cells via Acting as a Transcriptional Coactivator in p53-Mediated p21 Expression

2021 ◽  
Vol 11 ◽  
Author(s):  
Huili Li ◽  
Jiliang Wang ◽  
Kun Huang ◽  
Tao Zhang ◽  
Lu Gao ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Suppressor ◽  
Tumor Suppressor Gene ◽  
Expression Pattern ◽  
Cell Lines ◽  
Suppressor Gene ◽  
Transcriptional Coactivator ◽  
Wild Type ◽  
Mutational Status ◽  
Sw480 Cells

NK2 homeobox 5 (Nkx2.5), a homeobox-containing transcription factor, is associated with a spectrum of congenital heart diseases. Recently, Nkx2.5 was also found to be differentially expressed in several kinds of tumors. In colorectal cancer (CRC) tissue and cells, hypermethylation of Nkx2.5 was observed. However, the roles of Nkx2.5 in CRC cells have not been fully elucidated. In the present study, we assessed the relationship between Nkx2.5 and CRC by analyzing the expression pattern of Nkx2.5 in CRC samples and the adjacent normal colonic mucosa (NCM) samples, as well as in CRC cell lines. We found higher expression of Nkx2.5 in CRC compared with NCM samples. CRC cell lines with poorer differentiation also had higher expression of Nkx2.5. Although this expression pattern makes Nkx2.5 seem like an oncogene, in vitro and in vivo tumor suppressive effects of Nkx2.5 were detected in HCT116 cells by establishing Nkx2.5-overexpressed CRC cells. However, Nkx2.5 overexpression was incapacitated in SW480 cells. To further assess the mechanism, different expression levels and mutational status of p53 were observed in HCT116 and SW480 cells. The expression of p21WAF1/CIP1, a downstream antitumor effector of p53, in CRC cells depends on both expression level and mutational status of p53. Overexpressed Nkx2.5 could elevate the expression of p21WAF1/CIP1 only in CRC cells with wild-type p53 (HCT116), rather than in CRC cells with mutated p53 (SW480). Mechanistically, Nkx2.5 could interact with p53 and increase the transcription of p21WAF1/CIP1 without affecting the expression of p53. In conclusion, our findings demonstrate that Nkx2.5 could act as a conditional tumor suppressor gene in CRC cells with respect to the mutational status of p53. The tumor suppressive effect of Nkx2.5 could be mediated by its role as a transcriptional coactivator in wild-type p53-mediated p21WAF1/CIP1 expression.

scholarly journals Genetic determinants of EGFR-Driven Lung Cancer Growth and Therapeutic Response In Vivo

2020 ◽  
Author(s):  
Giorgia Foggetti ◽  
Chuan Li ◽  
Hongchen Cai ◽  
Jessica A. Hellyer ◽  
Wen-Yang Lin ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Tumor Growth ◽  
Lung Adenocarcinoma ◽  
Tumor Suppressor Gene ◽  
Suppressor Gene ◽  
Genetic Alterations ◽  
Putative Tumor Suppressor ◽  
Lung Adenocarcinomas ◽  
Gene Alterations

AbstractCancer genome sequencing has uncovered substantial complexity in the mutational landscape of tumors. Given this complexity, experimental approaches are necessary to establish the impact of combinations of genetic alterations on tumor biology and to uncover genotype-dependent effects on drug sensitivity. In lung adenocarcinoma, EGFR mutations co-occur with many putative tumor suppressor gene alterations, however the extent to which these alterations contribute to tumor growth and their response to therapy in vivo has not been explored experimentally. By integrating a novel mouse model of oncogenic EGFR-driven Trp53-deficient lung adenocarcinoma with multiplexed CRISPR–Cas9-mediated genome editing and tumor barcode sequencing, we quantified the effects of inactivation of ten putative tumor suppressor genes. Inactivation of Apc, Rb1, or Rbm10 most strongly promoted tumor growth. Unexpectedly, inactivation of Lkb1 or Setd2 – which are the strongest drivers of tumor growth in an oncogenic Kras-driven model – reduced EGFR-driven tumor growth. These results are consistent with the relative frequency of these tumor suppressor gene alterations in human EGFR- and KRAS-driven lung adenocarcinomas. Furthermore, Keap1 inactivation reduces the sensitivity of EGFR-driven Trp53-deficient tumors to the EGFR inhibitor osimertinib. Importantly, in human EGFR/TP53 mutant lung adenocarcinomas, mutations in the KEAP1 pathway correlated with decreased time on tyrosine kinase inhibitor treatment. Our study highlights how genetic alterations can have dramatically different biological consequences depending on the oncogenic context and that the fitness landscape can shift upon drug treatment.

scholarly journals Functional evidence for a second tumor suppressor gene on human chromosome 17

1994 ◽  
Vol 14 (1) ◽  
pp. 534-542
Author(s):  
P Chen ◽  
N Ellmore ◽  
B E Weissman
Keyword(s):  
Tumor Suppressor ◽  
Cell Line ◽  
Tumor Suppressor Gene ◽  
Cell Lines ◽  
Suppressor Gene ◽  
Chromosome 17 ◽  
Hybrid Cells ◽  
Tumorigenic Potential ◽  
Normal Human ◽  
Second Tumor

The development and progression of human tumors often involves inactivation of tumor suppressor gene function. Observations that specific chromosome deletions correlate with distinct groups of cancer suggest that some types of tumors may share common defective tumor suppressor genes. In support of this notion, our initial studies showed that four human carcinoma cell lines belong to the same complementation group for tumorigenic potential. In this investigation, we have extended these studies to six human soft tissue sarcoma cell lines. Our data showed that hybrid cells between a peripheral neuroepithelioma (PNET) cell line and normal human fibroblasts or HeLa cells were nontumorigenic. However, hybrid cells between the PNET cell line and five other soft tissue sarcoma cell lines remained highly tumorigenic, suggesting at least one common genetic defect in the control of tumorigenic potential in these cells. To determine the location of this common tumor suppressor gene, we examined biochemical and molecular polymorphic markers in matched pairs of tumorigenic and nontumorigenic hybrid cells between the PNET cell line and a normal human fibroblast. The data showed that loss of the fibroblast-derived chromosome 17 correlated with the conversion from nontumorigenic to tumorigenic cells. Transfer of two different chromosome 17s containing a mutant form of the p53 gene into the PNET cell line caused suppression of tumorigenic potential, implying the presence of a second tumor suppressor gene on chromosome 17.

scholarly journals Alterations of the p53 tumor suppressor gene in diffuse large cell lymphomas with translocations of the c-MYC and BCL-2 proto-oncogenes

Blood ◽  
1994 ◽  
Vol 83 (1) ◽  
pp. 191-198 ◽  
Author(s):  
MM Farrugia ◽  
LJ Duan ◽  
MD Reis ◽  
BY Ngan ◽  
NL Berinstein
Keyword(s):  
Tumor Suppressor ◽  
Cell Line ◽  
Tumor Suppressor Gene ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Large Cell ◽  
Suppressor Gene ◽  
Diffuse Large Cell Lymphoma ◽  
P53 Tumor Suppressor Gene ◽  
Large Cell Lymphoma

Abstract Diffuse large cell lymphomas are aggressive tumors of B-cell origin. In some cases they arise from low-grade follicular lymphomas carrying the t(14;18) translocation, an event that leads to the overexpression of the BCL-2 gene product. More frequently, however, they lack the t(14;18) translocation. Rearrangements of the c-MYC proto-oncogene and mutations of the p53 tumor suppressor gene have also been documented in these lymphomas. This study examines the extent to which alterations in the BCL-2, c-MYC, and p53 genes co-exist within individual lymphomas. Eight diffuse large cell lymphoma cell lines and 11 diffuse large cell lymphoma tumors were assessed for genetic alterations in these three genes. Our results indicate that there is a heterogeneity in the oncogene/suppressor gene profile among diffuse large cell lymphomas. Two cell lines and one tumor carried alterations in all three genes, one cell line carried alterations of c-MYC and p53, and one primary tumor and one cell line carried p53 mutations and the t(14;18). Single alterations of BCL-2 and p53 were also observed. Another cell line had no alterations in any of these genes. The heterogeneity indicates that varied mechanisms may be involved in the generation of diffuse large cell lymphomas.

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