Establishment of a monoclonal anti-pan HLA class I antibody suitable for immunostaining of formalin-fixed tissue: Unusually high frequency of down-regulation in breast cancer tissues

作者：Torigoe Toshihiko^*; Asanuma Hiroko; Nakazawa Emiri; Tamura Yasuaki; Hirohashi Yoshihiko; Yamamoto Eri; Kanaseki Takayuki; Hasegawa Tadashi; Sato Noriyuki

来源：Pathology International, 2012, 62(5): 303-308.

DOI：10.1111/j.1440-1827.2012.02789.x

• antigen presentation
• beta2-microglobulin
• breast cancer
• Immune escape
• MHC class I

A novel monoclonal anti-pan human leukocyte antigen (HLA) class I heavy chain antibody, EMR8-5, was established. It could detect HLA-A, -B, and -C antigens in formalin-fixed paraffin embedded tissues. By immunohistochemical staining using the EMR8-5 antibody, various cancer tissues from 246 cases were examined for HLA class I expression. It was found that HLA class I expression was decreased in 20% to 42% of the cases of lung cancer, hepatocellular carcinoma, colon cancer, renal cell carcinoma, and urothelial carcinoma. In contrast, 85% of breast cancer cases had loss of or decreased HLA class I expression. Of the 35 breast cancer cases that had decreased HLA class I heavy chain expression, 33 (94%) also had decreased beta2-microglobulin expression detected by immunohistochemical staining. It was suggested that HLA class I down-regulation might be a common characteristic of breast cancer mostly caused by the down-regulation of beta2-microglobulin expression.