Comparison of human mammary epithelial cells immortalized by simian virus 40 T-Antigen or by the telomerase catalytic subunit

• Published in: Oncogene Vol. 21; no. 1; pp. 128 - 139
• Main Authors: TOOULI, Christian D, HUSCHTSCHA, Lily I, NEUMANN, Axel A, NOBLE, Jane R, COLGIN, Lorel M, HUKKU, Bharati, REDDEL, Roger R
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing 03.01.2002; Nature Publishing Group
• Subjects: Adult; Aneuploidy; antigen T; Antigens, Polyomavirus Transforming - genetics; Antigens, Polyomavirus Transforming - physiology; Biological and medical sciences; Breast - cytology; Catalytic Domain; Cell Differentiation; Cell Line, Transformed; Cell Survival; Cell Transformation, Neoplastic; Cell Transformation, Viral; Chromosome Aberrations; Chromosomes, Human - ultrastructure; Cyclin-Dependent Kinase Inhibitor p16 - deficiency; Cyclin-Dependent Kinase Inhibitor p16 - physiology; Dactinomycin - pharmacology; DNA - drug effects; DNA Damage; Epithelial cells; Epithelial Cells - enzymology; Epithelial Cells - pathology; Epithelial Cells - virology; Female; Fundamental and applied biological sciences. Psychology; Genes, p16; Health aspects; Humans; Intercalating Agents - pharmacology; Karyotyping; Molecular and cellular biology; Physiological aspects; Protein Subunits; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - physiology; simian virus 40; Simian virus 40 - genetics; Simian virus 40 - physiology; SV40 (Virus); Telomerase; Telomerase - chemistry; Telomerase - genetics; Telomerase - physiology; Telomere - ultrastructure; Transfection; Australia; United States; Human; Catalytic subunit; Enzyme; Polyomavirus; V-Onc gene; Standard; Papovaviridae; Method; Simian virus 40; Virus; Plasmid; Epithelial cell; Early; Large T antigen; Mammary gland; T antigen; Telomerase; Comparative study
• ISSN: 0950-9232; 1476-5594
• DOI: 10.1038/sj.onc.1205014

We directly compared two methods of immortalizing human mammary epithelial cells (HMECs). Cells were transfected with an expression plasmid either for hTERT, the catalytic subunit of telomerase, or for the simian virus 40 (SV40) early region genes. Under standard culture conditions, HMECs were not immortalized by hTERT unless they had spontaneously ceased expression of the p16(INK4a) tumor suppressor gene. Untransfected HMECs had low levels of telomerase expression, and immortalization by both methods was associated with an increase in telomerase activity and prevention of telomere shortening. SV40-induced immortalization was accompanied by aberrant differentiation, loss of DNA damage response, karyotypic instability and, in some cases, tumorigenicity. hTERT-immortalized cells had fewer karyotypic changes, but had intact DNA damage responses, and features of normal differentiation. Although SV40-immortalized cells are useful for studies of carcinogenesis, hTERT-immortalized cells retain more properties of normal cells.