Microsatellite instability in colorectal cancer.

Microsatellite instability in colorectal cancer. Acta Biomed. 2018 Dec 17;89(9-S):97-101 Authors: De' Angelis GL, Bottarelli L, Azzoni C, De' Angelis N, Leandro G, Di Mario F, Gaiani F, Negri F Abstract Microsatellites are short tandem repeat DNA sequences of one to tetra base pairs distributed throughout the human genome, both in coding and non-coding regions. Owing to their repeated structure, microsatellites are particularly prone to replication errors that are normally repaired by the Mismatch Repair (MMR) system. MMR is a very highly conserved cellular process, involving many proteins, resulting in the identification, and subsequent repair of mismatched bases, likely to have arisen during DNA replication, genetic recombination or chemical or physical damage. Proteins within the MMR system include MLH1, PMS2, MSH2, MSH6, MLH3, MSH3, PMS1, and Exo1. Deficient MMR (dMMR) results in a strong mutator phenotype known as microsatellite instability (MSI), characterized by widespread length polymorphisms of microsatellite sequences due to DNA polymerase slippage. MSI is recognized as one of the major carcinogenetic pathways of colorectal cancer (CRC): it represents a molecular hallmark of hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome (LS); moreover it is detected in 15% of sporadic colorectal cancers, more often due to an epigenetic inactivation of MLH1. Identification of MSI CRC is important, as MSI may serve as a screening...
Source: Acta Bio-Medica : Atenei Parmensis - Category: General Medicine Authors: Tags: Acta Biomed Source Type: research

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ConclusionPathogenic/likely pathogenicMLH1/MSH2 variants account for a substantial proportion of CRC patients with HNPCC/suspected-HNPCC in Pakistan. Our findings suggest that HNPCC/suspected-HNPCC families should be tested for these recurrent variants prior to comprehensive gene screening in this population.
Source: Hereditary Cancer in Clinical Practice - Category: Cancer & Oncology Source Type: research
ConclusionFurther studies should be conducted to provide new insights about survival of colorectal carcinoma in Lynch syndrome, as well as the therapeutic alternatives for this neoplasia.ResumoIntroduçãoO carcinoma colorretal é a terceira neoplasia mais prevalente no mundo, bem como a segunda causa de morte por câncer. A maioria destas neoplasias são esporádicas, devidas a mutações somáticas, mas cerca de 15% são hereditárias como a síndrome de Lynch ou Hereditary Nonpolyposis Colorectal Cancer (HNPCC). Apesar de ser a mesma neoplasia, esta ...
Source: Journal of Coloproctology - Category: Gastroenterology Source Type: research
This study aimed to investigate the spectrum of germ-line mutations in Russian LS patients. LS-related mismatch repair (MMR) genes were analyzed in 16 patients, who were forwarded to genetic testing due to strong clinical features of LS and had high-level microsatellite instability (MSI-H) in the tumor (n = 14) or unknown MSI status (n = 2). In addition, 672 consecutive colorectal cancer (CRC) cases were screened for family history; 15 patients were younger than 50 years and reported 2 or more instances of LS-related cancers in 1st- or 2nd-degree relatives. Seven of these cases demonstrated MSI-H and th...
Source: European Journal of Medical Genetics - Category: Genetics & Stem Cells Authors: Tags: Eur J Med Genet Source Type: research
ConclusionsThis case highlights the importance of genetic testing with rare malignancies because the full scope of phenotypic sequelae for known hereditary syndromes has not been mapped.
Source: Journal of Medical Case Reports - Category: General Medicine Source Type: research
Abstract Hereditary non-polyposis colorectal cancer (HNPCC) also known as Lynch Syndrome (LS), is a hereditary form of colorectal cancer (CRC). LSis caused by mutations in the mismatch repair (MMR) genes, mostly in MLH1, MSH2, MSH6 and PMS2. Identification of these gene mutations is essential to diagnose CRC, especially at a young age to increase the survival rate. Using open target platform, we have performed genetic association studies to analyze the different genes involved in the LS and to obtain target for disease evidence. We have also analyzed upstream regulators as target molecules in the data sets. We dis...
Source: Bioinformation - Category: Bioinformatics Authors: Tags: Bioinformation Source Type: research
We describe a case that highlights the importance of a detailed family history.Case Rep Ophthalmol 2019;10:180 –185
Source: Case Reports in Ophthalmology - Category: Opthalmology Source Type: research
This review is an appraisal of the current state of knowledge of 2 enigmatic histotypes of ovarian carcinoma: endometrioid and clear cell carcinoma. Both show an association endometriosis and the hereditary nonpolyposis colorectal cancer (Lynch) syndrome, and both typically present at an early stage. Pathologic and immunohistochemical features that distinguish these tumors from high-grade serous carcinomas, each other, and other potential mimics are discussed, as are staging, grading, and molecular pathogenesis.
Source: Surgical Pathology Clinics - Category: Pathology Authors: Source Type: research
Introduction: Lynch syndrome or hereditary non-polyposis colon cancer (HNPCC) is inherited disorder in DNA mismatch repair genes which lead to microsatellite instability and increased risk of developing such cancers as colorectal, gastric, endometrial and others in relatively young adults under 50 years of age. Since genes who account for this syndrome have been identified and are transferred to next generations, many countries have launched a screening programme for selected patient groups to carry out prevention strategies.
Source: European Journal of Obstetrics, Gynecology, and Reproductive Biology - Category: OBGYN Authors: Tags: Basic Science 5 – Oncology Source Type: research
Abstract Colorectal cancer found to be the most commonly occurring cancer worldwide which can be prevented by screening and its curable if diagnosed early. Lynch syndrome/HNPCC being an autosomal genetic disease and propensity in forming colorectal cancer is inherited wherein genomic instabilities and epigenetic changes are being the characteristic forms in hereditary cancers. It is very important to determine the polymorphism in several DNA repairing genes such as ATM, RAD51, XRCC2, XRCC3 and XRCC9 to study the risk exploring both the prognosis and the developing of colorectal cancer. The role of ATM gene has bee...
Source: Acta Bio-Medica : Atenei Parmensis - Category: General Medicine Authors: Tags: Acta Biomed Source Type: research
Abstract Lynch syndrome (LS), an autosomal dominantly inherited disease previously known as hereditary non-polyposis colorectal cancer (HNPCC), leads to a high risk of colorectal cancer (CRC) as well as malignancy at certain sites including endometrium, ovary, stomach, and small bowel (Hampel et al., 2008; Lynch et al., 2009). Clinically, LS is considered the most common hereditary CRC-predisposing syndrome, accounting for about 3% of all CRC cases (Popat et al., 2005). LS is associated with mutations of DNA mismatch repair (MMR) genes such as MLH1, MSH2, MSH6, PMS2, and EPCAM (Ligtenberg et al., 2009; Lynch et al...
Source: J Zhejiang Univ Sci ... - Category: Science Authors: Tags: J Zhejiang Univ Sci B Source Type: research
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