title: Biochemical analysis of HLA class I subunits expression in breast cancer tissues.
abstract: The expression of HLA class I alpha-chain and beta(2)-m subunits was studied at the protein level by a semiquantitative Western blot (WB) approach, in 25 primary breast tumors. The results indicated three pathways of alterations defined comparing the tumor WB gel band with the corresponding PBL gel band: (i) high downregulation pattern (the tumor WB gel band was < or =50% relative to the PBL band), which was found in 44% and 36% of tumors for alpha-chain and beta(2)-m, respectively; (ii) low downregulation pattern (the tumor gel band was between 51% and 75%), which was found in 24% and 20% of tumors for alpha-chain and beta(2)75%), which was found in 32% and 44% of tumors for alpha-chain and beta(2)-m, respectively. The concordance rate with immunohistochemistry (IHC) performed on the same tissue samples was 72% for alpha-chain and 64% for beta(2)-m. This study shows that the use of a semiquantitative WB technique can well define the levels of HLA class I antigens in an autologous setting allowing the biochemical analysis of HLA class I downregulation directly in solid tumor tissues. In addition, the WB technique can be a valuable tool to objectively support the IHC method.
authors.affiliation: Immunogenetics Laboratory, National Cancer Institute c/o Advanced Biotechnology Center, Genova, Italy. pistillo@ermes.cba.unige.it
authors.forename: M P
authors.initials: MP
authors.lastname: Pistillo
authors.forename: G
authors.initials: G
authors.lastname: Nicolò
authors.forename: S
authors.initials: S
authors.lastname: Salvi
authors.forename: P
authors.initials: P
authors.lastname: Capanni
authors.forename: L
authors.initials: L
authors.lastname: Perdelli
authors.forename: G
authors.initials: G
authors.lastname: Pasciucco
authors.forename: G B
authors.initials: GB
authors.lastname: Ferrara
mesh_terms: D015153:Blotting, Western; D001943:Breast Neoplasms / Q000737:chemistry* / Q000276:immunology* / Q000473:pathology; D006680:HLA Antigens / Q000096:biosynthesis* / Q000737:chemistry*; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis* / Q000737:chemistry*; D006801:Humans; D007150:Immunohistochemistry; D013194:Staining and Labeling; D001613:beta 2-Microglobulin / Q000096:biosynthesis / Q000737:chemistry
chemical_list: D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D001613:beta 2-Microglobulin