SMALL-CELL LUNG-CARCINOMA CELL-LINES EXPRESS MESSENGER-RNA FOR CALCITONIN AND ALPHA-CALCITONIN AND BETA-CALCITONIN GENE-RELATED PEPTIDES

Calcitonin (CT) and calcitonin gene related peptide (CGRP) are derived from preprohormones encoded by three mRNAs (CT, alpha-CGRP and beta-C GRP) from two genes (CALC1 and CALC2) on chromosome 11. Among 16 small cell lung cancer cell lines examined by RNase protection assay, 9 (56 %) had detectable CT mRNA, 8 (50%) had alpha-CGRP mRNA, and 13 (81%) h ad beta-CGRP mRNA. At least one CALC1 transcript (CT or alpha-CGRP) wa s found in 11 (69%) cell lines with three having only CT mRNA, two hav ing only alpha-CGRP mRNA, and six having both. beta-CGRP mRNA was dete cted in all of these 11 cell lines expressing a CALC1 transcript. Immu noreactive CT was detected by radioimmunoassay in eight of nine SCLC c ell lines expressing CT mRNA, and immunoreactive CGRP was detected in 12 of 13 cell lines expressing a CGRP mRNA. The variety of expression of these three peptides in different cell lines of the same cell type should provide a useful system for further study of the control of exp ression of these peptides.