A large proportion of colorectal carcinomas (CRC) evolve from colorectal adenomas. However, not all individuals with colonic adenomas have a risk of CRC substantially higher than those of the general population. The aim of the study was to determine the differences or similarities of mutation profile among low- and high-grade adenomas and in situ carcinoma with detailed follow up. We have investigated the mutation spectrum of well-known genes involved in CRC (such as APC, BRAF, EGFR, NRAS, KRAS, PIK3CA, POLE, POLD1, SMAD4, PTEN, and TP53) in a large, well-defined series of 96 adenomas and in situ carcinomas using a high-throughput genotyping technique. Besides, the microsatellite instability and APC and MLH1 promoter methylation were studied as well. We observed a high frequency of pathogenic variants in the studied genes. The APC, KRAS and TP53 mutation frequencies were slightly lower in adenoma samples than in in situ carcinoma samples. Further, when we stratified mutation frequency based on the grade, the frequency distribution was as follows: low-grade adenoma-high-grade adenomas-in situ carcinoma: APC gene 42.9-56.0-54.5%; KRAS gene 32.7-32.0-45.5%; TP53 gene 8.2-20.0-18.2%. The occurrence of KRAS mutation was associated with the presence of villous histology and methylation of the APC promoter was significantly associated with the presence of POLE genetic variations. However, no association was noticed with the presence of any singular mutation and occurrence of subsequent adenoma or CRC. Our data supports the multistep model of gradual accumulation of mutations, especially in the driver genes, such as APC, TP53 and KRAS.

• MeSH
• adenom genetika   patologie   MeSH
• karcinom in situ genetika   patologie   MeSH
• kolorektální nádory genetika   patologie   MeSH
• lidé MeSH
• metylace DNA MeSH
• mikrosatelitní nestabilita * MeSH
• mutace * MeSH
• nádorové biomarkery genetika   MeSH
• následné studie MeSH
• prognóza MeSH
• senioři MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• nádorové biomarkery MeSH

The phenotypic effects of single nucleotide polymorphisms (SNPs) in the development of sporadic solid cancers are still scarce. The aim of this review was to summarise and analyse published data on the associations between SNPs in mismatch repair genes and various cancers. The mismatch repair system plays a unique role in the control of the genetic integrity and it is often inactivated (germline and somatic mutations and hypermethylation) in cancer patients. Here, we focused on germline variants in mismatch repair genes and found the outcomes rather controversial: some SNPs are sometimes ascribed as protective, while other studies reported their pathological effects. Regarding the complexity of cancer as one disease, we attempted to ascertain if particular polymorphisms exert the effect in the same direction in the development and treatment of different malignancies, although it is still not straightforward to conclude whether polymorphisms always play a clear positive role or a negative one. Most recent and robust genome-wide studies suggest that risk of cancer is modulated by variants in mismatch repair genes, for example in colorectal cancer. Our study shows that rs1800734 in MLH1 or rs2303428 in MSH2 may influence the development of different malignancies. The lack of functional studies on many DNA mismatch repair SNPs as well as their interactions are not explored yet. Notably, the concerted action of more variants in one individual may be protective or harmful. Further, complex interactions of DNA mismatch repair variations with both the environment and microenvironment in the cancer pathogenesis will deserve further attention.

• Klíčová slova
• cancer, genes, genetic variants, genotype, mismatch repair, patients, single nucleotide polymorphism, treatment outcome,
• MeSH
• homolog 2 proteinu MutS genetika   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• lidé MeSH
• metylace DNA genetika   MeSH
• MutL homolog 1 genetika   MeSH
• nádory genetika   patologie   MeSH
• oprava chybného párování bází DNA genetika   MeSH
• progrese nemoci MeSH
• zárodečné mutace genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• homolog 2 proteinu MutS MeSH
• MLH1 protein, human MeSH Prohlížeč
• MSH2 protein, human MeSH Prohlížeč
• MutL homolog 1 MeSH