title: Rat vascular smooth muscle cells immortalized with SV40 large T antigen possess defined smooth muscle cell characteristics including growth inhibition by heparin.
abstract: Rat aortic smooth muscle cells (SMC) have been established by retroviral delivery of the complementary DNA (cDNA) for the simian virus 40 large T antigen (SV40LT) and examined for SMC phenotypic markers and growth characteristics, including responsiveness to the antiproliferative effects of heparin. The transfected cells (SV40LT-SMC) maintain defined SMC characteristics for more than 215 population doublings (PD) as judged by muscle-specific actin expression and growth inhibition by heparin. SV40LT-SMC greater than 129 PD become transformed while SV40LT-SMC less than 77 PD resemble nontransfected SMC morphologically and are nontumorigenic. SV40LT-SMC apparently release a growth factor which acts in an autocrine fashion, since (1) suramin inhibits SV40LT-SMC proliferation, (2) SV40LT-SMC-conditioned medium (CM) contains mitogenic activity, and (3) SV40LT-SMC CM suppresses the binding of platelet-derived growth factor to SMC. Heparin (10-100 micrograms/ml) is a potent inhibitor of both early (less than 80 PD) and late-passage (greater than 80 PD) SV40LT-SMC proliferation. The antiproliferative effects of heparin are similar to those previously observed for SMC by several criteria; the dose-response inhibition curves are indistinguishable from those obtained with nontransfected cells, other glycosaminoglycans have little effect on SV40LT-SMC growth, the antiproliferative effects of heparin are reversed in the presence of epidermal growth factor, and heparin displays high-affinity saturable binding to SV40LT-SMC. In conclusion, SV40LT-SMC are a continuous line of SMC-like cells that are sensitive to the growth inhibitor, heparin. SV40LT-SMC should facilitate studies of heparin inhibition and may be applicable for the study of other SMC characteristics as well.
authors.affiliation: Department of Pharmacology, Merck Sharp and Dohme Research Laboratories, West Point, Pennsylvania 19486.
authors.forename: C F
authors.initials: CF
authors.lastname: Reilly
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D001012:Aorta, Abdominal; D001769:Blood; D002455:Cell Division / Q000187:drug effects; D002461:Cell Line, Transformed; D004247:DNA / Q000235:genetics; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D005822:Genetic Vectors; D006493:Heparin / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010641:Phenotype; D051381:Rats; D011919:Rats, Inbred Strains; D011923:Rats, Nude; D012190:Retroviridae / Q000235:genetics; D013539:Simian virus 40 / Q000276:immunology*; D014162:Transfection
chemical_list: D000199:Actins; D000952:Antigens, Polyomavirus Transforming; D006493:Heparin; D004247:DNA