scholarly journals Disruption of ubiquitin mediated proteolysis is a widespread mechanism of tumorigenesis

2018 ◽  
Author(s):  
Francisco Martinez-Jimenez ◽  
Ferran Muinos ◽  
Erika Lopez-Arribillaga ◽  
Nuria Lopez-Bigas ◽  
Abel Gonzalez-Perez
Keyword(s):  
Random Forest ◽  
Positive Selection ◽  
Somatic Mutations ◽  
Random Forest Classifier ◽  
Human Proteome ◽  
Cancer Development ◽  
Driver Mutations ◽  
Primary Tumors ◽  
E3 Ligases ◽  
Cancer Types

E3 ligases and degrons --the sequences they recognize in target proteins-- are key parts of the ubiquitin-mediated proteolysis system. There are several examples of alterations of these two components of the system that play a role in cancer. Here, we uncovered the landscape of the contribution of such alterations to tumorigenesis across cancer types. We first systematically identified novel instances of degrons across the human proteome using a random forest classifier, and validated them exploiting somatic mutations across more than 7,000 tumors. We detected signals of positive selection across these novel degrons and revealed new instances involved in cancer development. Overall, we estimated that at least one in seven driver mutations across primary tumors affect either degrons or E3 ligases.

scholarly journals Mutational landscape of primary, metastatic, and recurrent ovarian cancer reveals c-MYC gains as potential target for BET inhibitors

2018 ◽  
Vol 116 (2) ◽  
pp. 619-624 ◽  
Author(s):  
Charles Li ◽  
Elena Bonazzoli ◽  
Stefania Bellone ◽  
Jungmin Choi ◽  
Weilai Dong ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Somatic Mutations ◽  
Driver Mutations ◽  
Cancer Evolution ◽  
Metastatic Tumors ◽  
Driver Genes ◽  
Primary Tumors ◽  
Mutational Landscape ◽  
Recurrent Tumors ◽  
Bet Inhibitors

Ovarian cancer remains the most lethal gynecologic malignancy. We analyzed the mutational landscape of 64 primary, 41 metastatic, and 17 recurrent fresh-frozen tumors from 77 patients along with matched normal DNA, by whole-exome sequencing (WES). We also sequenced 13 pairs of synchronous bilateral ovarian cancer (SBOC) to evaluate the evolutionary history. Lastly, to search for therapeutic targets, we evaluated the activity of the Bromodomain and Extra-Terminal motif (BET) inhibitor GS-626510 on primary tumors and xenografts harboring c-MYC amplifications. In line with previous studies, the large majority of germline and somatic mutations were found in BRCA1/2 (21%) and TP53 (86%) genes, respectively. Among mutations in known cancer driver genes, 77% were transmitted from primary tumors to metastatic tumors, and 80% from primary to recurrent tumors, indicating that driver mutations are commonly retained during ovarian cancer evolution. Importantly, the number, mutation spectra, and signatures in matched primary–metastatic tumors were extremely similar, suggesting transcoelomic metastases as an early dissemination process using preexisting metastatic ability rather than an evolution model. Similarly, comparison of SBOC showed extensive sharing of somatic mutations, unequivocally indicating a common ancestry in all cases. Among the 17 patients with matched tumors, four patients gained PIK3CA amplifications and two patients gained c-MYC amplifications in the recurrent tumors, with no loss of amplification or gain of deletions. Primary cell lines and xenografts derived from chemotherapy-resistant tumors demonstrated sensitivity to JQ1 and GS-626510 (P = 0.01), suggesting that oral BET inhibitors represent a class of personalized therapeutics in patients harboring recurrent/chemotherapy-resistant disease.

The landscape of somatic mutation in normal colorectal epithelial cells

2018 ◽  
Author(s):  
Henry Lee-Six ◽  
Peter Ellis ◽  
Robert J. Osborne ◽  
Mathijs A. Sanders ◽  
Luiza Moore ◽  
...  
Keyword(s):  
Normal Tissue ◽  
Somatic Mutations ◽  
Cell Lineage ◽  
Driver Mutations ◽  
Normal Cells ◽  
Genetic Changes ◽  
Adult Cell ◽  
Neoplastic Change ◽  
Cancer Types ◽  
Mutational Processes

AbstractThe colorectal adenoma-carcinoma sequence has provided a paradigmatic framework for understanding the successive somatic genetic changes and consequent clonal expansions leading to cancer. As for most cancer types, however, understanding of the earliest phases of colorectal neoplastic change, which may occur in morphologically normal tissue, is comparatively limited because of the difficulty of detecting somatic mutations in normal cells. Each colorectal crypt is a small clone of cells derived from a single recently-existing stem cell. Here, we whole genome sequenced hundreds of normal crypts from 42 individuals. Signatures of multiple mutational processes were revealed, some ubiquitous and continuous, others only found in some individuals, in some crypts or during some phases of the cell lineage from zygote to adult cell. Likely driver mutations were present in ∼1% of normal colorectal crypts in middle-aged individuals, indicating that adenomas and carcinomas are rare outcomes of a pervasive process of neoplastic change across morphologically normal colorectal epithelium.

scholarly journals Aberrant mitochondrial function in ageing and cancer

2019 ◽  
Vol 21 (4) ◽  
pp. 445-459 ◽  
Author(s):  
Julia C. Whitehall ◽  
Laura C. Greaves
Keyword(s):  
Risk Factor ◽  
Cancer Cells ◽  
Tumour Growth ◽  
Somatic Mutations ◽  
Mitochondrial Metabolism ◽  
Cancer Development ◽  
Mtdna Mutations ◽  
Age Related ◽  
Mitochondrial Functions ◽  
Cancer Types

AbstractAlterations in mitochondrial metabolism have been described as one of the major hallmarks of both ageing cells and cancer. Age is the biggest risk factor for the development of a significant number of cancer types and this therefore raises the question of whether there is a link between age-related mitochondrial dysfunction and the advantageous changes in mitochondrial metabolism prevalent in cancer cells. A common underlying feature of both ageing and cancer cells is the presence of somatic mutations of the mitochondrial genome (mtDNA) which we postulate may drive compensatory alterations in mitochondrial metabolism that are advantageous for tumour growth. In this review, we discuss basic mitochondrial functions, mechanisms of mtDNA mutagenesis and their metabolic consequences, and review the evidence for and against a role for mtDNA mutations in cancer development.

scholarly journals Genomic Determinants of Homologous Recombination Deficiency across Human Cancers

Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4572
Author(s):  
Tao Qing ◽  
Xinfeng Wang ◽  
Tomi Jun ◽  
Li Ding ◽  
Lajos Pusztai ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Copy Number ◽  
Somatic Mutations ◽  
Synthetic Lethality ◽  
Driver Mutations ◽  
Multiple Cancer ◽  
Clinical Biomarkers ◽  
Somatic Alterations ◽  
Cancer Types ◽  
Prostate Cancers

Germline BRCA1/2 mutations associated with HRD are clinical biomarkers for sensitivity to poly-ADP ribose polymerase inhibitors (PARPi) treatment in breast, ovarian, pancreatic, and prostate cancers. However, it remains unclear whether other mutations may also lead to HRD and PARPi sensitivity across a broader range of cancer types. Our goal was to determine the germline or somatic alterations associated with the HRD phenotype that might therefore confer PARPi sensitivity. Using germline and somatic genomic data from over 9000 tumors representing 32 cancer types, we examined associations between HRD scores and pathogenic germline variants, somatic driver mutations, and copy number deletions in 30 candidate genes involved in homologous recombination. We identified several germline and somatic mutations (e.g., BRCA1/2, PALB2, ATM, and ATR mutations) associated with HRD phenotype in ovarian, breast, pancreatic, stomach, bladder, and lung cancer. The co-occurrence of germline BRCA1 variants and somatic TP53 mutations was significantly associated with increasing HRD in breast cancer. Notably, we also identified multiple somatic copy number deletions associated with HRD. Our study suggests that multiple cancer types include tumor subsets that show HRD phenotype and should be considered in the future clinical studies of PARPi and synthetic lethality strategies exploiting HRD, which can be caused by a large number of genomic alterations.

scholarly journals Pathway-based dissection of the genomic heterogeneity of cancer hallmarks’ acquisition with SLAPenrich

2016 ◽  
Author(s):  
Francesco Iorio ◽  
Luz Garcia-Alonso ◽  
Jonathan S. Brammeld ◽  
Iñigo Martincorena ◽  
David R. Wille ◽  
...  
Keyword(s):  
Somatic Mutations ◽  
Population Level ◽  
Computational Method ◽  
Driver Mutations ◽  
Cancer Type ◽  
Cancer Genes ◽  
Driver Genes ◽  
Cancer Hallmarks ◽  
Pathway Gene ◽  
Cancer Types

ABSTRACTCancer hallmarks are evolutionary traits required by a tumour to develop. While extensively characterised, the way these traits are achieved through the accumulation of somatic mutations in key biological pathways is not fully understood. To shed light on this subject, we characterised the landscape of pathway alterations associated with somatic mutations observed in 4,415 patients across ten cancer types, using 374 orthogonal pathway gene-sets mapped onto canonical cancer hallmarks. Towards this end, we developed SLAPenrich: a computational method based on population-level statistics, freely available as an open source R package. Assembling the identified pathway alterations into sets of hallmark signatures allowed us to connect somatic mutations to clinically interpretable cancer mechanisms. Further, we explored the heterogeneity of these signatures, in terms of ratio of altered pathways associated with each individual hallmark, assuming that this is reflective of the extent of selective advantage provided to the cancer type under consideration. Our analysis revealed the predominance of certain hallmarks in specific cancer types, thus suggesting different evolutionary trajectories across cancer lineages.Finally, although many pathway alteration enrichments are guided by somatic mutations in frequently altered high-confidence cancer genes, excluding these driver mutations preserves the hallmark heterogeneity signatures, thus the detected hallmarks’ predominance across cancer types. As a consequence, we propose the hallmark signatures as a ground truth to characterise tails of infrequent genomic alterations and identify potential novel cancer driver genes and networks.

The Performance Improvement on 4-FB Face using Random Forest Classifier

2018 ◽  
Vol 10 (5) ◽  
pp. 1-12
Author(s):  
B. Nassih ◽  
A. Amine ◽  
M. Ngadi ◽  
D. Naji ◽  
N. Hmina
Keyword(s):  
Random Forest ◽  
Performance Improvement ◽  
Random Forest Classifier

Identification of BAP1-associated MicroRNAs and Implications in Cancer Development

2019 ◽  
pp. 1-4
Author(s):  
Tikam Chand ◽  
Tikam Chand
Keyword(s):  
Gene Regulation ◽  
In Silico ◽  
Mirna Target ◽  
Target Prediction ◽  
Differential Regulation ◽  
Cancer Development ◽  
Mirna Target Prediction ◽  
Cancer Types ◽  
In Silico Tools

Having role in gene regulation and silencing, miRNAs have been implicated in development and progression of a number of diseases, including cancer. Herein, I present potential miRNAs associated with BAP1 gene identified using in-silico tools such as TargetScan and Exiqon miRNA Target Prediction. I identified fifteen highly conserved miRNA (hsa-miR-423-5p, hsa-miR-3184-5p, hsa-miR-4319, hsa-miR125b-5p, hsa-miR-125a-5p, hsa-miR-6893-3p, hsa-miR-200b-3p, hsa-miR-200c-3p, hsa-miR-505-3p.1, hsa-miR-429, hsa-miR-370-3p, hsa-miR-125a-5p, hsa-miR-141-3p, hsa-miR-200a-3p, and hsa-miR-429) associated with BAP1 gene. We also predicted the differential regulation of these twelve miRNAs in different cancer types.

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