The high-frequency microsatellite instability (MSI-H) phenotype, frequently identified in hereditary nonpolyposis colorectal cancer (HNPCC), also accounts for approximately 15% of sporadic colorectal cancers. Microsatellite instability (MSI) occurs from the mutational inactivation of the DNA mismatch repair genes, i.e. hMSH2 and hMLH1 in HNPCC, as well as from epigenetic inactivation of hMLH1 i...

The DNA mismatch repair (MMR) system is responsible for the detection and correction of errors created during DNA replication, thereby avoiding the incorporation of mutations in dividing cells. The prognostic value of alterations in MMR system has not previously been analyzed in oral squamous cell carcinoma (OSCC).The study comprised 115 cases of OSCC diagnosed between 1996 and 2010. The specim...

BACKGROUND In a previous study we identified 206 patients with colorectal adenocarcinoma in the Northern Cape province of South Africa, diagnosed between January 2002 and February 2009. The age-standardised incidence was 4.2/100 000 per year world standard population. This is 10% of the rate reported in First-World countries. In high-incidence areas, the rate of abnormal mismatch repair gene ex...

Hereditary Nonpolyposis Colorectal Cancer (HNPCC) is a genetically heterogeneous disorder caused by germ-line mutations in one of several DNA mismatch repair (MMR) genes, most commonly in hMSH2 and hMLH1. Human exonuclease 1 (hExo1) possesses both 5'exonuclease and flap endonuclease activities and plays a role in DNA repair, recombination, and replication. The enzyme interacts with MMR proteins...

Hereditary non-polyposis colorectal cancer (HNPCC) is a very important clinical entity in oncology. In order to identify HNPCC, the international diagnostic criteria named "Amsterdam criteria" have been used. In this report, we present a case of an HNPCC patient who met the revised Amsterdam criteria after the sequential history taking in which a novel germline mutation of hMSH2 gene was detect...

The process of post-replicative DNA-mismatch repair seems to be highly evolutionarily conserved. In Escherichia coli, DNA mismatches are recognized by the MutS protein. Homologues of the E. coli mutS and mutL mismatch-repair genes have been identified in other prokaryotes, as well as in yeast and mammals. Recombinant Saccharomyces cerevisiae MSH2 (MSH for MutS homologue) and human hMSH2 protein...

Germline mutations of the hMSH2 gene are responsible for many cases of hereditary nonpolyposis colorectal cancer. While screening for hMSH2 gene mutations in hereditary nonpolyposis colorectal cancer kindreds, we observed that a previously reported germline mutation is in fact a common, alternatively spliced variant in the population. Using RT-PCR and the protein truncation test, the hMSH2 exon...

This study aimed to identify the status of 2 major microsatellite instability markers (repair genes hMSH2 and hMSH6) in colorectal cancer cases operated at King Khalid University Hospital, Riyadh, Saudi Arabia between 2007 and 2009. Immunohistochemical study of microsatellite instability was done with antibodies to hMSH2 and hMSH6. A total of 32 blocks were analysed from patients aged 16-83 yea...

BACKGROUND Helicobacer pylori infection is a major gastric cancer risk factor. Deficient DNA mismatch repair (MMR) caused by H. pylori may underlie microsatellite instability (MSI) in the gastric epithelium and may represent a major mechanism of mutation accumulation in the gastric mucosa during the early stages of H. pylori-associated gastric carcinogenesis. In this study, we examined the expr...