COLOCALIZATION OF 3 NEUROPEPTIDES AND NADPH DIAPHORASE IN A SMALL-CELL LUNG-CARCINOMA CELL-LINE

Background - The small cell lung cancer (SCLC) is an epithelial tumour with the morphological and secretory characteristics of neuroendocrin e cells (neurone-specific enolase, N-CAM, neuropeptides). The establis hment of a SCLC cell line provides an in vitro model to analyze the ne uroendocrine secretion of these malignant cells. Methods - Bombesin, d elta sleep inducing factor (DSIP) and arginine vasopressin (AVP) were studied by immunohistochemistry and by in situ hybridization. NADPH di aphorase activity was detected using an histochemical technique. Resul ts - All the cells contained bombesin, DSIP, AVP and displayed a NADPH diaphorase activity with reflects a nitric oxide (NO) synthase activi ty. Conclusions - These data present the characteristics of a new SCLC cell line (CPN) and show the complexity of its neuroendocrine secreti on; for example, the presence of DSIP and NO synthase activity which h ave not yet been demonstrated in other SCLC cell lines.