The specific goal of this project is to determine whether_normal- human cells contain genes that have the ability to suppress tumorigenicity of human lung carcinoma cell lines. Somatic cell hybrids between a lung carcinoma line, HuT292-DM, and BEAS-2B, an immortalized, but non-tumorigenic human bronchial epithelial line, have been generated by fusion with polyethylene glycol (PEG), followed by double selection in hypoxanthine/aminopterin/thymidine (HAT) medium containing ouabain. The properties of these hybrid lines are being studied. All lines have near triploid chromosome numbers, whereas the parental lines are near diploid. Serum induces BEAS-2B to terminally differentiate, but stimulates the growth of the carcinoma line. The hybrids vary in their response to serum. Some are unaffected, some are stimulated, but none are inhibited. The tumorigenicity of these lines as compared to their progenitors is now being tested in nude, athymic mice.
