Clonal variation in phenotype and life span of human embryonic fibroblasts (MRC-5) transduced with the catalytic component of telomerase (hTERT).
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.
Franco
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S
Laboratory of Developmental Hematopoiesis, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
MacKenzie
K L
KL
Dias
S
S
Alvarez
S
S
Rafii
S
S
Moore
M A
MA
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
D004268:DNA-Binding Proteins; D006133:Growth Substances; D019715:Tissue Inhibitor of Metalloproteinase-1; C422952:telomerase RNA; D016685:Mitomycin; D012313:RNA; D019098:Telomerase; D018093:Gelatinases