Cloning and characterization of a tumor-associated antigen, beta-casein-like protein

Monoclonal antibody (MAb) 1C5 reacts with 87% of uterine cervical adenocarc inoma and bovine beta -casein, but not with squamous cell carcinoma. To cla rify the characteristics of the antigen (beta -casein-like protein; BCLP) r ecognized by MAb 1C5, molecular cloning was performed using 5 ' rapid ampli fication of the cDNA ends (5 ' RACE) and the oligo-capping method. The prot ein predicted from the cDNA consisting of 937 nucleotides comprises 222 ami no acids. The BCLP gene and deduced amino acid sequences were novel and sho wed no similarity to known cancer-associated genes in the database. Norther n blot analysis showed that a 1.1 kb transcript was ubiquitously expressed in cancer cell lines and was predominantly expressed in uterine cervical ad enocarcinoma. To clarify the function of BCLP, BCLP cDNA was transfected in to L929 cells, resulting in a significant increase in cell area, a downregu lation of cell growth rate and a decrease in cell attachment. We conclude t hat BCLP might be associated with cell morphology and a regulation of growt h pattern of tumor. (C) 2001 Academic Press.