Biochemical analysis of HLA class I subunits expression in breast cancer tissues.
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.
Pistillo
M P
MP
Immunogenetics Laboratory, National Cancer Institute c/o Advanced Biotechnology Center, Genova, Italy. pistillo@ermes.cba.unige.it
Nicolò
G
G
Salvi
S
S
Capanni
P
P
Perdelli
L
L
Pasciucco
G
G
Ferrara
G B
GB
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
D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D001613:beta 2-Microglobulin