Methylation of the p16(INK4a) promoter region in telomerase immortalized human keratinocytes co-cultured with feeder cells
Language: 
English
Abstract: 

Human keratinocytes grown in co-culture with fibroblast feeder cells have an extended in vitro lifespan and delayed accumulation of the tumor suppressor protein p16(INK4a) when compared to the same cells grown on tissue culture plastic alone. Previous studies have indicated that human keratinocytes can be immortalized by telomerase activity alone when grown in co-culture with feeder cells, suggesting that loss of the p16(INK4a)/Rb pathway is not required for immortalization. Using two independent human keratinocyte cell strains, we found that exogenous telomerase expression and co-culture with feeder cells results in efficient extension of lifespan without an apparent crisis. However, when these cells were transferred from the co-culture environment to plastic alone they experienced only a brief period of slowed growth before continuing to proliferate indefinitely. Examination of immortal cell lines demonstrated p16(INK4a) promoter methylation had occurred in both the absence and presence of feeder cells. Reintroduction of p16(INK4a) into immortal cell lines resulted in rapid growth arrest. Our results suggest that p16(INK4a)/Rb-induced telomere-independent senescence, although delayed in the presence of feeders, still provides a proliferation barrier to human keratinocytes in this culture system and that extended culture of telomerase-transduced keratinocytes on feeders can lead to the methylation of p16(INK4a).

Author(s): 
Darbro, B. W.
Lee, K. M.
Nguyen, N. K.
Domann, F. E.
Klingelhutz, A. J.
Item Type: 
Journal Article
Publication Title: 
Oncogene
Journal Abbreviation: 
Oncogene
Publication Date: 
11/30/2006
Publication Year: 
2006
Pages: 
7421-7433
Volume: 
25
Issue: 
56
ISSN: 
0950-9232
DOI: 
10.1038/sj.onc.1209729
Library Catalog: 
NCBI Published Medical (?)
Extra: 
PMID: 16767161 PMCID: PMC1894570

Turabian/Chicago Citation

B. W. Darbro, K. M. Lee, N. K. Nguyen, F. E. Domann and A. J. Klingelhutz. 11/30/2006. "Methylation of the p16(INK4a) promoter region in telomerase immortalized human keratinocytes co-cultured with feeder cells." Oncogene 25: 56: 7421-7433. 10.1038/sj.onc.1209729.

Wikipedia Citation

<ref> {{Cite journal | doi = 10.1038/sj.onc.1209729 | issn = 0950-9232 | volume = 25 | pages = 7421-7433 | last = Darbro | first = B. W. | coauthors = Lee, K. M., Nguyen, N. K., Domann, F. E., Klingelhutz, A. J. | title = Methylation of the p16(INK4a) promoter region in telomerase immortalized human keratinocytes co-cultured with feeder cells | journal = Oncogene | date = 11/30/2006 | pmid = | pmc = }} </ref>