CLINICAL CORRELATES OF BOMBESIN-LIKE PEPTIDE RECEPTOR SUBTYPE EXPRESSION IN HUMAN LUNG-CANCER CELLS

The importance of the expression of the autocrine growth system for bo mbesin-like peptides (BLPS) to the biological behavior of human lung c ancer has not been determined. Three BLP receptor subtypes have been i dentified in human lung and lung cancer cells: gastrin-releasing pepti de (GRP) receptor, neuromedin B (NMB) receptor, and bombesin receptor subtype 3 (BRS-3). The goals of this study were: (1) to determine BLP receptor subtype expression by human lung cancer cell lines by RT/PCR; (2) to evaluate possible clinical correlates of characteristics of th e patients from whom the cell lines were derived with patterns of BLP receptor expression. Degenerate PCR primers were designed to amplify a ll known BLP receptors and yielded products from 19/20 small cell lung carcinoma (SCLC) and 12/13 non-small cell lung carcinoma (NSCLC) cell lines. GRP receptor was the most commonly expressed BLP receptor subt ype, being detected in 17/20 SCLC and 11/13 NSCLC. Eleven of 20 SCLC e xpressed NMB receptors, and 5/20 expressed BRS-3, compared with 4/13 a nd 1/13, respectively, in NSCLC cell lines. Evaluation of the clinical data of the patients from whom the cell lines were derived revealed e xpected age, sex, smoking history and survival based on histology and stage. Patients from whom cell lines expressed GRP receptor experience d a better survival than those whose cell lines did not (367 +/- 274 d ays vs. 211 +/- 114 days), but the results were not statistically sign ificant. RT/PCR analysis is a feasible, sensitive and specific means o f determining BLP receptor expression in lung cancer cells and may yie ld prognostic information in patient tissue.