This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cate, C. C. Articles by Sorenson, G. D. Search for Related Content PubMed PubMed Citation Articles by Cate, C. C. Articles by Sorenson, G. D.

Biosynthesis of Procalcitonin in Small Cell Carcinoma of the Lung¹

Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire 03756

Immunoreactive calcitonin (CT) secreted by DMS 53, a cell line derived from human small cell carcinoma of the lung, consists almost entirely of molecular species larger than the mature hormone (M_r 3,420). Messenger RNA isolated from DMS 53 cells and nude mouse tumors was translated in wheat germ systems, and the products were precipitated with CT-specific antisera. Analyses of the translation products by electrophoresis on 15% polyacrylamide-sodium dodecyl sulfate gels indicated synthesis of a M_r 16,500 preprohormone that was reduced to M_r 14,500 by cotranslation with microsomal membranes. Immunoprecipitation of CT from media from pulse-labeled cultures revealed two major products (M_r 16,500 and M_r 14,500) and up to three minor secreted polypeptides (M_r 9,400, 8,400, and 6,800). Intracellular CT from cell homogenates appeared almost entirely as a single major product (M_r 14,500) and possibly 3–4 minor components (M_r 16,500; 9,200, 8,400, and 6,800). No glycosylated forms of CT were demonstrable by lectin binding methods or labeling attempts with tritiated sugars. The presence of multiple CT species in DMS 53 cells suggests significant post-translational processing of the larger precursor molecules and the accumulation and secretion by small cell carcinoma of the lung of several intermediate immunoreactive forms via a glycosylation-independent secretory pathway.

¹ This work was supported in part by USPHS Grants CA 33207, CA 33852, and BRSG 2507 RR05392-22.

² To whom requests for reprints should be addressed.

Received 10/19/84. Revised 5/23/85. Revised 9/26/85. Accepted 10/24/85.

This article has been cited by other articles:

				A. Polzin, M. Pletz, R. Erbes, M. Raffenberg, H. Mauch, S. Wagner, G. Arndt, and H. Lode Procalcitonin as a diagnostic tool in lower respiratory tract infections and tuberculosis Eur. Respir. J., June 1, 2003; 21(6): 939 - 943. [Abstract] [Full Text] [PDF]

				R. K. Ravi, A. Thiagalingam, E. Weber, M. McMahon, B. D. Nelkin, and M. Mabry Raf-1 Causes Growth Suppression and Alteration of Neuroendocrine Markers in DMS53 Human Small-Cell Lung Cancer Cells Am. J. Respir. Cell Mol. Biol., April 1, 1999; 20(4): 543 - 549. [Abstract] [Full Text]