Immunohistochemical Analysis of WT1 Antigen Expression in Various Solid Cancer Cells

Naitoh K1, Kamigaki T2, Matsuda E2, Ibe H2, Okada S2, Oguma E2, Kinoshita Y2, Takimoto R2, Makita K2, Ogasawara S2, Goto S2.

Anticancer Res. 2016 Jul;36(7):3715-24.

Abstract

For a peptide-pulsed dendritic cell (DC) vaccine to work effectively in cancer treatment, it is significant that the target protein is expressed in cancer cells. Wilms' tumor 1 (WT1) has been identified as a molecular target for immune cell therapy of cancer. We evaluated the protein expression levels of WT1 in various solid tumors, as well as mucin 1 (MUC1) or major histocompatibility complex (MHC) class l molecules. Seven hundred and thirty-eight patients whose tissue samples were examined by immunohistochemicalanalysis agreed to undergo DC vaccine therapy. The positive staining of WT1 in tumor cells was observed in 25.3% of patients, with only 8.5% of them showing moderate to strong expression; moreover, WT1 tended to localize in the nucleus and cytoplasm. A positive staining of tumor cells by an anti-MHC class l monoclonal antibody was observed in 98.6% and by an anti-MUC1 monoclonal antibody in 76.8% of the patients. In relation to the application of cancer-specific immunotherapy, these findings provide useful information for determining the efficacy of MUC1- and WT1-targeted therapy.