Nicotine effects on proliferation and the bombesin-like peptide autocrine system in human small cell lung carcinoma SHP77 cells in culture

Objectives: To determine whether nicotine affects the proliferation and expression of the bombesin-like peptide autocrine system in human small cell lung carcinoma (SCLC) SHP77 cells compared with nonmalignant human bronchial epithelial BEAS 2B cells as non-neuroendocrine controls. Methods: Human lung cells were cultured in defined serum-free medium with various concentrations of nicotine added for various times. Proliferation was measured by cell counts and colorimetric assay, bombesin-like peptide receptor expression was assayed by specific binding assays and quantitative competitive PCR, and bombesin-like peptides determined by ELISA. Results: Nicotine significantly stimulated the growth of human SCLC SHP77 and NCI-H865 cells, but not PEAS 2B cells. Bombesin-like peptide receptor specific binding and mRNA expression were not affected by nicotine exposure in SHP77 cells or BEAS 2B cells. An increase in SHP77 cellular bombesin-like peptide content was observed. Conclusions: Human SCLC SHP77 cells express the components of the bombesin-like peptide autocrine system. Increased proliferation in the presence of nicotine may be due in part to increased levels of bornbesin-like peptides in SHP77 cultured in nicotine. Nicotine effects on nonmalignant pulmonary neuroendocrine cells may provide additional insight into how nicotine itself may promote lung carcinogenesis. (C) 2000 Published by Elsevier Science Ireland Ltd.