title: Regulation of the expression of major histocompatibility complex class I genes in human colorectal cancer.
abstract: Products encoded by the major histocompatibility complex class I genes are down-regulated in many tumors. The under-representation of HLA antigens in human tumors is usually associated with a poor prognosis. In this report, the expression of HLA genes in human colorectal carcinomas was studied using HLA-A and HLA-B locus-specific probes. Over 50% of the colorectal carcinomas studied showed a reduction in the amount of steady-state HLA mRNA. For some carcinomas, non-coordinated regulation of the HLA-A and HLA-B genes was observed. The HLA expression in some, but not all cases, could be enhanced by gamma-interferon. Over 60% of the colorectal carcinomas also expressed high level of the c-myc oncogene mRNA. However, no correlation could be made between the increase of c-myc expression and the down-regulation of the HLA genes.
authors.affiliation: Institute of Molecular and Cell Biology, National University of Singapore, Republic of Singapore.
authors.forename: T W
authors.initials: TW
authors.lastname: Soong
authors.forename: K M
authors.initials: KM
authors.lastname: Hui
mesh_terms: D002277:Carcinoma / Q000201:enzymology / Q000235:genetics*; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000201:enzymology / Q000235:genetics*; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D005805:Genes, MHC Class I / Q000235:genetics*; D016259:Genes, myc / Q000235:genetics; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; D007371:Interferon-gamma; D015500:Chloramphenicol O-Acetyltransferase