title: MHC class II genotype- and MHC class I and II phenotype-related parameters in sporadic colorectal cancer.
abstract: The underlying etiological cause of non-hereditary colorectal cancer has yet to be determined. The adenoma-carcinoma sequence is widely accepted, however, a sole trigger has not been specified. Therefore, we sought to further define genotypic and phenotypic parameters that could be involved in promoting a possible infection, inflammation and hyper-proliferation, followed by the adenoma-carcinoma sequence. Expression of phenotype-related parameters for MHC class I (HLA-A N-20 and β2 microglobulin) and class II (HLA-DRα and HLA-DR) as well as CD45 and carcinoembryonic antigen (CEA) were investigated immunohistochemically in a series of 93 colorectal cancers. Additionally, in 49 of the tumours the MHC class II genotype was analysed. MHC class II genotype analyses revealed a tendency towards DRB1*08 and DQB1*04. A significant association among the MHC class I markers or the MHC class II markers was found. No difference in marker expression could be detected between tumour and stromal tissue, however a significant inverse expression existed for markers of the functionally different class I or II systems. With the exception of CEA, there was no correlation between expression of any marker and tumour grade. Only 2% of tumours expressed no markers for MHC class I and II. Further studies on MHC class I and II genotype and phenotype relation in colorectal cancer may help to identify trigger mechanisms for tumourigenesis, involved markers and possible mechanisms of subsequent immune escape.
authors.affiliation: Department of Surgery, Georgius Agricola Hospital, Saalfeld, Germany.
authors.forename: Toralf
authors.initials: T
authors.lastname: Wolkersdörfer
authors.forename: Monika
authors.initials: M
authors.lastname: Füssel
authors.forename: Tobias
authors.initials: T
authors.lastname: Kiesslich
authors.forename: Daniel
authors.initials: D
authors.lastname: Neureiter
authors.forename: Frieder
authors.initials: F
authors.lastname: Berr
authors.forename: Daniela
authors.initials: D
authors.lastname: Aust
authors.forename: Gernot W
authors.initials: GW
authors.lastname: Wolkersdörfer
mesh_terms: D000328:Adult; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D005260:Female; D005787:Gene Frequency; D015234:HLA-A Antigens / Q000235:genetics* / Q000276:immunology; D006684:HLA-DR Antigens / Q000235:genetics* / Q000276:immunology; D059805:HLA-DR alpha-Chains / Q000235:genetics / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D017493:Leukocyte Common Antigens / Q000235:genetics* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D001613:beta 2-Microglobulin / Q000235:genetics* / Q000276:immunology
chemical_list: D015234:HLA-A Antigens; D006684:HLA-DR Antigens; D059805:HLA-DR alpha-Chains; D001613:beta 2-Microglobulin; D017493:Leukocyte Common Antigens; C516769:PTPRC protein, human