Search results for "Mismatch Repair"
showing 10 items of 81 documents
Natural Selection Fails to Optimize Mutation Rates for Long-Term Adaptation on Rugged Fitness Landscapes
2008
The rate of mutation is central to evolution. Mutations are required for adaptation, yet most mutations with phenotypic effects are deleterious. As a consequence, the mutation rate that maximizes adaptation will be some intermediate value. Here, we used digital organisms to investigate the ability of natural selection to adjust and optimize mutation rates. We assessed the optimal mutation rate by empirically determining what mutation rate produced the highest rate of adaptation. Then, we allowed mutation rates to evolve, and we evaluated the proximity to the optimum. Although we chose conditions favorable for mutation rate optimization, the evolved rates were invariably far below the optimu…
CD63 and Dna Mismatch Repair Protein Expression in Prostate Cancer
2021
Abstract Protein expression levels in immunohistochemistry and molecular biomarkers have been reported for their ability to predict recurrence, progression, development of metastases, and patient survival. The molecular features in low- and high-grade prostate cancer can differ and influence treatment decision and prognosis. The objective of the current study was to compare the expression of exosomal biomarkers CD63 and mismatch repair proteins (MSH2, MSH6, MLH1, and PMS2) by immunohistochemistry (IHC) in tissue of patients with prostate cancer and benign hyperplasia. Altogether, 62 patients with prostate acinar adenocarcinoma and 20 patients with prostate benign hyperplasia were enrolled i…
Lack of association between screening interval and cancer stage in Lynch syndrome may be accounted for by over-diagnosis; a prospective Lynch syndrom…
2019
Background Recent epidemiological evidence shows that colorectal cancer (CRC) continues to occur in carriers of pathogenic mismatch repair (path_MMR) variants despite frequent colonoscopy surveillance in expert centres. This observation conflicts with the paradigm that removal of all visible polyps should prevent the vast majority of CRC in path_MMR carriers, provided the screening interval is sufficiently short and colonoscopic practice is optimal. Methods To inform the debate, we examined, in the Prospective Lynch Syndrome Database (PLSD), whether the time since last colonoscopy was associated with the pathological stage at which CRC was diagnosed during prospective surveillance. Path_MMR…
Uptake of hysterectomy and bilateral salpingo-oophorectomy in carriers of pathogenic mismatch repair variants:a Prospective Lynch Syndrome Database r…
2021
Purpose: This study aimed to report the uptake of hysterectomy and/or bilateral salpingo-oophorectomy (BSO) to prevent gynaecological cancers (risk-reducing surgery [RRS]) in carriers of pathogenic MMR (path_MMR) variants.Methods: The Prospective Lynch Syndrome Database (PLSD) was used to investigate RRS by a cross-sectional study in 2292 female path_MMR carriers aged 30-69 years.Results: Overall, 144, 79, and 517 carriers underwent risk-reducing hysterectomy, BSO, or both combined, respectively. Two-thirds of procedures before 50 years of age were combined hysterectomy and BSO, and 81% of all procedures included BSO. Risk-reducing hysterectomy was performed before age 50 years in 28%, 25%,…
Molecular subtyping of colon cancer (CC) based on mutational status of RAS, BRAF, and DNA mismatch repair (MMR) proteins. Prognostic value.
2016
e15094Background: CC is a heterogeneuous disease with clinical, pathological and biological variability. Molecular classification could indentify prognostic subtypes. Methods: 105 patients with sta...
Molecular Basis of Mismatch Repair Protein Deficiency in Tumors from Lynch Suspected Cases with Negative Germline Test Results
2020
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Converging endometrial and ovarian tumorigenesis in Lynch syndrome: Shared origin of synchronous carcinomas.
2018
AbstractObjective The diagnosis of carcinoma in both the uterus and the ovary simultaneously is not uncommon and raises the question of synchronous primaries vs. metastatic disease. Targeted sequencing of sporadic synchronous endometrial and ovarian carcinomas has shown that such tumors are clonally related and thus represent metastatic disease from one site to the other. Our purpose was to investigate whether or not the same applies to Lynch syndrome (LS), in which synchronous cancers of the gynecological tract are twice as frequent as in sporadic cases, reflecting inherited defects in DNA mismatch repair (MMR). Methods MMR gene mutation carriers with endometrial or ovarian carcinoma or en…
Epigenetic regulation of DNA repair genes and implications for tumor therapy
2017
DNA repair represents the first barrier against genotoxic stress causing metabolic changes, inflammation and cancer. Besides its role in preventing cancer, DNA repair needs also to be considered during cancer treatment with radiation and DNA damaging drugs as it impacts therapy outcome. The DNA repair capacity is mainly governed by the expression level of repair genes. Alterations in the expression of repair genes can occur due to mutations in their coding or promoter region, changes in the expression of transcription factors activating or repressing these genes, and/or epigenetic factors changing histone modifications and CpG promoter methylation or demethylation levels. In this review we …
Dysregulation of DNA methylation induced by past arsenic treatment causes persistent genomic instability in mammalian cells
2015
The mechanisms by which arsenic-induced genomic instability is initiated and maintained are poorly understood. To investigate potential epigenetic mechanisms, in this study we evaluated global DNA methylation levels in V79 cells and human HaCaT keratinocytes at several time points during expanded growth of cell cultures following removal of arsenite exposures. We have found altered genomic methylation patterns that persisted up to 40 cell generations in HaCaT cells after the treatments were withdrawn. Moreover, mRNA expression levels were evaluated by RT-PCR for DNMT1, DNMT3A, DNMT3B, HMLH1, and HMSH2 genes, demonstrating that the down regulation of DNMT3A and DNMT3B genes, but not DNMT1, o…
Integrated analysis of colorectal cancer microRNA datasets: Identification of microRNAs associated with tumor development
2018
Colorectal cancer (CRC) is one of the leading cause of cancer death worldwide. Currently, no effective early diagnostic biomarkers are available for colorectal carcinoma. Therefore, there is a need to discover new molecules able to identify pre-cancerous lesions. Recently, microRNAs (miRNAs) have been associated with the onset of specific pathologies, thus the identification of miRNAs associated to colorectal cancer may be used to detect this pathology at early stages. On these bases, the expression levels of miRNAs were analyzed to compare the miRNAs expression levels of colorectal cancer samples and normal tissues in several miRNA datasets. This analysis revealed a group of 19 differentia…