Circulating antibodies to p40(AIS) in the sera of respiratory tract cancerpatients

Studies of immune recognition in cancer have defined several tumor antigens using autologous cytotoxic T lymphocytes and by detection of serum antibod ies to tumor-associated products such as p53 and HER-2/neu. The AIS gene is a p53 homologue with multiple protein products (p40, p51, p63, p73L) on ch romosomal arm 3q, frequently amplified and over-expressed in squamous-cell carcinoma of the respiratory tract. We analyzed the humoral response to p40 (AIS) (a core domain of AIS products without the transactivation domain) by Western blot and ELISA using bacterially synthesized p40(AIS) protein. Ant ibodies were detected in the sera of 17/94 (18%) HNSCCs and 13/76 (17%) lun g cancers, including 5/18 (26%) squamous-cell carcinomas. Anti-p40(AIS) ant ibodies were not associated with factors such as sex, age, histopathologica l grading, extent or size of primary tumor, lymph node involvement and stag ing. Our results indicate that amplification and over-expression of p40(AIS ) may lead to antigen recognition by an autologous host with cancer. AIS ma y thus represent a new group of developmentally regulated genes that are re cognized as tumor antigens. Int. J. Cancer (Pred. Oncol.) 89:524-528, 2000. (C) 2000 Wiley-Liss, Inc.