Biological significance of beta hCG, HLA and other membrane antigen expression on bladder tumours and their relationship to tumour infiltrating lymphocytes (TIL).

Expression of beta human chorionic gonadotropin (beta hCG) by bladder tumours has been shown to be associated with increased metastases and resistance to treatment with radiotherapy and chemotherapy. Preliminary results from typing frozen tumours using monoclonal antibodies against HLA determinants show reduced or lost expression of one or more antigens in two thirds of patients studied with a trend for more malignant behaviour and inability to generate tumour infiltrating lymphocyte expression using Interleukin-2 in those patients whose tumours demonstrate loss. In this series beta hCG expression was only seen in a subgroup of those demonstrating loss of HLA antigen expression. Studies of beta hCG secreting bladder cancer cell lines showed that it was possible to induce class II HLA antigen expression with gamma Interferon, and that this treatment but not alpha Interferon reduced beta hCG production by the cell line.