{"title":"Suppression of neoplastic transformation and regulation of cytoskeleton by tropomyosins.","authors":"V Shah, R Braverman, G L Prasad","doi":"10.1023/b:scam.0000007130.08611.fc","DOIUrl":null,"url":null,"abstract":"<p><p>Down regulation of Tropomyosins (TMs) is a consistent biochemical change observed in many transformed cells. Our previous work has demonstrated that Tropomyosin-1 is an antioncogene and it is a class II tumor suppressor. Using ras-transformed murine fibroblasts (DT cells), we have examined the effects of co-expression of two isoforms of TM on cell morphology, cytoskeleton and tumorigenecity. Enhanced expression of TM1, a suppressor of transformation, along with TM2 which is not a tumor suppressor results in the formation of well-organized microfilaments, a morphology that resembles normal fibroblasts, and suppression of tumorigenecity. Tumor formation in vivo was compatible with the persistence of high-level of TM2, but not TM1. Homodimers of TM1 and TM2 were observed in these cells. Thus, restoration of expression of TM1 and TM2 protein in ras-transformed cells suppresses the transformed phenotype with dramatic re-organization of microfilaments. These data show that TM2 cooperates with TM1 in the reorganization of microfilaments, while TM1 is a suppressor of the transformed phenotype.</p>","PeriodicalId":21884,"journal":{"name":"Somatic Cell and Molecular Genetics","volume":"24 5","pages":"273-80"},"PeriodicalIF":0.0000,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/b:scam.0000007130.08611.fc","citationCount":"30","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Somatic Cell and Molecular Genetics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1023/b:scam.0000007130.08611.fc","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 30
Abstract
Down regulation of Tropomyosins (TMs) is a consistent biochemical change observed in many transformed cells. Our previous work has demonstrated that Tropomyosin-1 is an antioncogene and it is a class II tumor suppressor. Using ras-transformed murine fibroblasts (DT cells), we have examined the effects of co-expression of two isoforms of TM on cell morphology, cytoskeleton and tumorigenecity. Enhanced expression of TM1, a suppressor of transformation, along with TM2 which is not a tumor suppressor results in the formation of well-organized microfilaments, a morphology that resembles normal fibroblasts, and suppression of tumorigenecity. Tumor formation in vivo was compatible with the persistence of high-level of TM2, but not TM1. Homodimers of TM1 and TM2 were observed in these cells. Thus, restoration of expression of TM1 and TM2 protein in ras-transformed cells suppresses the transformed phenotype with dramatic re-organization of microfilaments. These data show that TM2 cooperates with TM1 in the reorganization of microfilaments, while TM1 is a suppressor of the transformed phenotype.