Lack of HLA class II antigen expression in microsatellite unstable colorectal carcinomas is caused by mutations in HLA class II regulatory genes.

ABSTRACT: Colorectal cancers (CRCs) develop on the basis of a deficient DNA mismatch repair (MMR) system in about 15% of cases. MMR-deficient CRC lesions show high-level microsatellite instability (MSI-H) and accumulate numerous mutations located at coding microsatellite loci that lead to the generation of immunogenic neopeptides. Consequently, the host's antitumoral immune response is of high importance for the course of the disease in MSI-H CRC patients. Accordingly, immune evasion mediated by impairment of HLA class I antigen presentation is frequently observed in these cancers. In this study, we aimed at a systematic analysis of alterations affecting HLA class II antigen expression in MSI-H CRC. HLA class II antigens are expressed by only two-thirds of MSI-H CRCs. The mechanisms underlying the l

SUBMITTER: Michel S 

PROVIDER: S-EPMC2892639 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature