title: Clonal variation in phenotype and life span of human embryonic fibroblasts (MRC-5) transduced with the catalytic component of telomerase (hTERT).
abstract: Expression of telomerase (hTERT) in certain cell types has been shown to extend cellular life span without malignant transformation. We studied the phenotype of 26 telomerase-transduced fibroblast clones (TTFC) generated from a mass culture of hTERT retrovirally transduced MRC-5 cells. About two-thirds of the transduced clones senesced at the expected time or shortly thereafter, despite high levels of expression of telomerase and telomere length maintenance. The remaining one-third of the clones were "immortalized" (followed for over 200 cumulative population doublings). All clones maintained a nontransformed phenotype: contact inhibition, anchorage dependency, lack of tumor formation in nude mice, dose dependency to serum and growth factors, low expression of a matrix metalloproteinase associated with metastatic invasion (MMP-9) and high expression of its inhibitor TIMP-1, and no cytogenetic abnormalities by G-banding. In addition, fibroblast-specific biological parameters, such as colony size, production of collagenase, and response to MMC and gamma radiation were tightly regulated at the clonal and subclonal levels.
authors.affiliation: Laboratory of Developmental Hematopoiesis, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
authors.forename: S
authors.initials: S
authors.lastname: Franco
authors.forename: K L
authors.initials: KL
authors.lastname: MacKenzie
authors.forename: S
authors.initials: S
authors.lastname: Dias
authors.forename: S
authors.initials: S
authors.lastname: Alvarez
authors.forename: S
authors.initials: S
authors.lastname: Rafii
authors.forename: M A
authors.initials: MA
authors.lastname: Moore
mesh_terms: D000818:Animals; D020134:Catalytic Domain / Q000235:genetics; D002455:Cell Division / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D002460:Cell Line; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D002999:Clone Cells / Q000166:cytology / Q000378:metabolism / Q000637:transplantation; D003114:Colony-Forming Units Assay; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism* / Q000637:transplantation; D005720:Gamma Rays; D018093:Gelatinases / Q000096:biosynthesis; D006133:Growth Substances / Q000096:biosynthesis / Q000494:pharmacology; D006801:Humans; D007621:Karyotyping; D051379:Mice; D008819:Mice, Nude; D016685:Mitomycin / Q000494:pharmacology; D010641:Phenotype; D012313:RNA; D019098:Telomerase / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D016615:Telomere / Q000378:metabolism*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis; D014161:Transduction, Genetic; D014183:Transplantation, Heterologous
chemical_list: D004268:DNA-Binding Proteins; D006133:Growth Substances; D019715:Tissue Inhibitor of Metalloproteinase-1; C422952:telomerase RNA; D016685:Mitomycin; D012313:RNA; D019098:Telomerase; D018093:Gelatinases