Influence of laminin substratum on cell proliferation and CALC I gene expression in medullary thyroid carcinoma C cell lines

• Published in: Molecular and cellular endocrinology Vol. 157; no. 1; pp. 181 - 189
• Main Authors: Lekmine, F, Lausson, S, Pidoux, E, Segond, N, Roos, B, Treilhou-Lahille, F, Jeanne, N
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 25.11.1999
• Subjects: Animals; Calcitonin; Calcitonin - drug effects; Calcitonin - genetics; Calcitonin - metabolism; Calcitonin gene-related peptide; Calcitonin Gene-Related Peptide - drug effects; Calcitonin Gene-Related Peptide - genetics; Calcitonin Gene-Related Peptide - metabolism; Carcinoma, Medullary - genetics; Carcinoma, Medullary - metabolism; Cell Division - drug effects; Extracellular matrix; Humans; Laminin; Laminin - pharmacology; Laminin - physiology; Laminin - ultrastructure; Medullary thyroid carcinoma; Mice; Protein Isoforms - pharmacology; Rats; RNA, Messenger - analysis; RNA, Messenger - drug effects; Thyroid Neoplasms - genetics; Thyroid Neoplasms - metabolism; Tumor Cells, Cultured - metabolism; Calcitonin gene-related peptide; Extracellular matrix; Laminin; Calcitonin; Medullary thyroid carcinoma
• ISSN: 0303-7207; 1872-8057
• DOI: 10.1016/S0303-7207(99)00138-0

Medullary thyroid carcinoma (MTC) originates from C cells, which secrete calcitonin (CT) and CT gene-related peptide (CGRP), the two splice peptide products of the CALC I gene. Normal and hyperplastic C cells are intrafollicular, in contact with the basement membrane (BM) that is maintained around the differentiated tumors. To investigate the relationships between MTC evolution and BM constituents, we examined the modifications induced by laminin-1 and -2 (merosin), two isoforms colocalized in the follicular BM, on three MTC cell lines: murine rMTC 6-23 and CA-77 cells, and human TT cells. Laminin exerted a mitogenic activity on rMTC 6-23 and on TT cells, causing a concurrent decrease in both CT and CGRP mRNA levels and production of the peptides. Conversely, laminin reduced the proliferation rate and enhanced CGRP synthesis and secretion in CA-77 cells. This antiproliferative response, which coincides with an increase in differentiation markers, is comparable to that reported in normal cells and also in the neoplastic Caco-2 cell line. This suggests that laminin could exert opposite effects depending on the stage of tumor evolution.