Haploinsufficiency of Tumor Suppressor Genes is Driven by the Cumulative Effect of microRNAs, microRNA Binding Site Polymorphisms and microRNA Polymorphisms: An in silico Approach

Haploinsufficiency of tumor suppressor genes, wherein the reduced production and activity of proteins results in the inability of the cell to maintain normal cellular function, is one among the various causes of cancer. However the precise molecular mechanisms underlying this condition remain unclear. Here we hypothesize that single nucleotide polymorphisms (SNPs) in the 3′untranslated region (UTR) of mRNAs and microRNA seed sequence (miR-SNPs) may cause haploinsufficiency at the level of proteins through altered binding specificity of microRNAs (miRNAs). Bioinformatics analysis of haploinsufficient genes for variations in their 3′UTR showed that the occurrence of SNPs result in the creation of new binding sites for miRNAs, thereby bringing the respective mRNA variant under the control of more miRNAs. In addition, 19 miR-SNPs were found to result in non-specific binding of microRNAs to tumor suppressors. Networking analysis suggests that the haploinsufficient tumor suppressor genes strongly interact with one another, and any subtle alterations in this network will contribute to tumorigenesis.

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Molecular Pathogenesis of MDS

Hematology ◽

10.1182/asheducation-2005.1.156 ◽

2005 ◽

Vol 2005 (1) ◽

pp. 156-160 ◽

Cited By ~ 41

Author(s):

A. Thomas Look

Keyword(s):

Tumor Suppressor ◽

Progenitor Cells ◽

Tumor Suppressors ◽

Tumor Suppressor Genes ◽

Molecular Mechanisms ◽

Point Mutations ◽

Suppressor Genes ◽

Hematopoietic Stem ◽

Chromosomal Deletions ◽

Genes Encoding

Abstract Clonal disorders of hematopoiesis, such as myelodysplastic syndromes (MDS) and myeloproliferative diseases (MPD), affect both hematopoietic stem cells and progenitor cells within the erythroid, platelet and granulocytic lineages and can have devastating consequences in children and adults. The genetic features of these diseases often include clonal, nonrandom chromosomal deletions (e.g., 7q–, 5q–, 20q–, 6q–, 11q– and 13q–) that appear to inactivate tumor suppressor genes required for the normal development of myeloid cells (reviewed in Bench1 and Fenaux2). These putative tumor suppressors have proved to be much more difficult to identify than oncogenes activated by chromosomal translocations, the other major class of chromosomal lesions in MDS and MPD.3 Although MDS and MPD are almost certainly caused by mutations in stem/progenitor cells,4 the role of inactivated tumor suppressor genes in this process remains poorly understood. In a small portion of myeloid diseases, mutations have been identified in genes encoding factors known to be required for normal hematopoiesis, such as PU.1, RUNX1, CTNNA1 (α-catenin) and c/EBPα, and implicating these genes as tumor suppressors.5–7 Nonetheless, the identities of most deletion-associated tumor suppressors in these diseases remains elusive, despite complete sequencing of the human genome. The deleted regions detected by cytogenetic methods are generally very large, containing many hundreds of genes, thus making it hard to locate the critical affected gene or genes. It is also unclear whether dysfunctional myelopoiesis results from haploinsufficiency, associated with the deletion of one allele, or from homozygous inactivation due to additional point mutations or microdeletions of the retained wild-type allele. In general MDS have proved surprisingly resistant to conventional treatments. Targeted therapeutic advances in MDS will likely depend on a full comprehension of underlying molecular mechanisms, in particular the tumor suppressor genes lost through clonal, nonrandom chromosomal deletions, such as the 7q– and (del)5q.

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ALV-J and REV synergistically activate a new oncogene of KIAA1199 via NF-κB and EGFR signaling regulated by miR-147

10.1101/338244 ◽

2018 ◽

Author(s):

Defang Zhou ◽

Jingwen Xue ◽

Pingping Zhuang ◽

Xiyao Cui ◽

Shuhai He ◽

...

Keyword(s):

Tumor Suppressor ◽

Molecular Mechanism ◽

Tumor Suppressor Genes ◽

Large Scale ◽

Molecular Mechanisms ◽

Tumor Formation ◽

Signalling Pathway ◽

Suppressor Genes ◽

Pathway Crosstalk ◽

Pathogenic Effects

AbstractThe tumorigenesis is the result of the accumulation of multiple oncogenes and tumor suppressor genes changes. Co-infection of avian leucosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV), as two oncogenic retroviruses, showed synergistic pathogenic effects characterized by enhanced tumor initiation and progression. The molecular mechanism underlying synergistic effects of ALV-J and REV on the neoplasia remains unclear. Here, we found co-infection of ALV-J and REV enhanced the ability of virus infection, increased viral life cycle, maintained cell survival and enhanced tumor formation. We combined the high-throughput proteomic readout with a large-scale miRNA screening to identify which molecules are involved in the synergism. Our results revealed co-infection of ALV-J and REV activated a latent oncogene of KIAA1199 and inhibited the expression of tumor suppressor miR-147. Further, enhanced KIAA1199, down-regulated miR-147, activated NF-κB and EGFR were demonstrated in co-infected tissues and tumor. Mechanistically, we showed ALV-J and REV synergistically enhanced KIAA1199 by activation of NF-κB and EGFR signalling pathway, and the suppression of tumor suppressor miR-147 was contributed to maintain the NF-κB/KIAA1199/EGFR pathway crosstalk by targeting the 3’UTR region sequences of NF-κB p50 and KIAA1199. Our results contributed to the understanding of the molecular mechanisms of viral synergistic tumorgenesis, which provided the evidence that suggested the synergistic actions of two retroviruses could result in activation of latent pro-oncogenes.Author summaryThe tumorigenesis is the result of the accumulation of multiple oncogenes and tumor suppressor genes changes. Co-infection with ALV-J and REV showed synergistic pathogenic effects characterized by enhanced tumor progression, however, the molecular mechanism on the neoplasia remains unclear. Our results revealed co-infection of ALV-J and REV promotes tumorigenesis by both induction of a latent oncogene of KIAA1199 and suppression of the expression of tumor suppressor miR-147. Mechanistic studies revealed that ALV-J and REV synergistically enhance KIAA1199 by activation of NF-κB and EGFR signalling pathway, and the suppression of tumor suppressor miR-147 was contributed to maintain the NF-κB/KIAA1199/EGFR pathway crosstalk by targeting the 3’UTR region sequences of NF-κB p50 and KIAA1199. These results provided the evidence that suggested the synergistic actions of two retroviruses could result in activation of latent pro-oncogenes, indicating the potential preventive target and predictive factor for ALV-J and REV induced tumorigenesis.

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Copy number analysis to identify tumor suppressor genes associated with enzalutamide (Enza) resistance and poor prognosis in metastatic castration-resistant prostate cancer (mCRPC) patients.

Journal of Clinical Oncology ◽

10.1200/jco.2019.37.15_suppl.5011 ◽

2019 ◽

Vol 37 (15_suppl) ◽

pp. 5011-5011

Author(s):

Xiangnan Guan ◽

Duan-Chen Sun ◽

Eric Lu ◽

Joshua A. Urrutia ◽

Robert Evan Reiter ◽

...

Keyword(s):

Overall Survival ◽

Tumor Suppressor ◽

Tumor Suppressor Genes ◽

Copy Number ◽

Poor Prognosis ◽

Molecular Mechanisms ◽

Prognostic Significance ◽

Copy Number Loss ◽

Castration Resistant Prostate Cancer ◽

Suppressor Genes

5011 Background: Although enza prolongs life in mCRPC pts, the development of drug resistance and subsequent disease progression is nearly universal. Seeking to clarify molecular mechanisms that underlie enza resistance, we analyzed whole genome sequencing (WGS) and RNA sequencing (seq) of tumors obtained from patients with enza-naive or -resistant mCRPC. Methods: One hundred and one men with mCRPC who underwent image-guided biopsy and subsequent WGS were included (n = 64 with enza-naive and n = 37 with enza-resistant mCRPC). The differential copy number alteration (CNA) events enriched in enza-resistant vs. naïve samples were determined, and the prognostic significance of differential CNAs was assessed. RNA-seq data were evaluated to confirm that CNAs correlated with changes in gene expression of relevant loci and to identify potentially druggable targets selectively activated in tumors with specific CNAs. Results: Copy number loss was more common than gain in enza-resistant tumors. Specifically, we identified 123 protein-coding genes that were more commonly lost in enza-resistant samples—eight of which were previously described tumor suppressor genes. There was a strong concordance of copy number loss and reduced mRNA expression of these genes. We identified one gene from this list of eight genes whose copy number loss was associated with poor overall survival (median overall survival from date of CRPC was 19.1 months in tumors with gene loss vs. 42.0 months in intact tumors, hazard ratio 3.8 [1.46–9.8], log-rank p = 0.003). Finally, Master Regulator analysis determined that tumors with copy number loss of this poor prognosis gene had activation of several potentially targetable factors, including the kinases Akt and PLK1. Conclusions: Copy number loss of specific tumor suppressor genes is associated with enza resistance in mCRPC patients. Previously unappreciated molecular subsets of enza-resistant CRPC were identified, including one subset associated with poor clinical outcome.

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Nongenic cancer-risk SNPs affect oncogenes, tumor suppressor genes, and immune function

10.1101/507236 ◽

2018 ◽

Cited By ~ 1

Author(s):

M. Fagny ◽

J. Platig ◽

M.L. Kuijjer ◽

X. Lin ◽

J. Quackenbush

Keyword(s):

Tumor Suppressor ◽

Cancer Risk ◽

Tumor Suppressor Genes ◽

Eqtl Analysis ◽

Nucleotide Polymorphisms ◽

Bipartite Networks ◽

Suppressor Genes ◽

Tissue Specific ◽

Increased Risk ◽

Risk Snps

AbstractGenome-wide associations studies (GWASes) have identified many germline genetic variants that are associated with an increased risk of developing cancer. However, how these single nucleotide polymorphisms (SNPs) alter biological function in a way that increases cancer risk is still largely unknown. We used a systems biology approach to analyze the regulatory role and functional associations of cancer-risk SNPs in thirteen distinct tissues. Using data from the Genotype-Tissue Expression (GTEx) project, we performed an expression quantitative trait locus (eQTL) analysis, keeping both cis- and trans-eQTLs, and representing those significant associations as edges in tissue-specific eQTL bipartite networks. We find that each network is organized into highly modular communities that group sets of SNPs together with functionally-related collections of genes. We mapped cancer-risk SNPs to each tissue-specific eQTL network. Although we find in each tissue that cancer-risk SNPs are distributed across the network, they are not uniformly distributed. Rather they are significantly over-represented in a small number of communities. This includes communities enriched for immune response processes as well as communities representing tissue-specific functions. Moreover, cancer-risk SNPs are over-represented in the central “cores” of communities, meaning they are more likely to influence the expression of many genes within the same community, thus affecting biological processes. And finally, we find that cancer-risk SNPs preferentially target oncogenes and tumor suppressor genes, suggesting non-genic mutations may still alter the effects of these key cancer-associated genes. This bipartite eQTL network approach provides a new way of understanding genetic effects on cancer risk and provides a biological context for interpreting the results of GWAS cancer studies.

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