Reconstitution of telomerase activity combined with HPV-E7 expression allow human preadipocytes to preserve their differentiation capacity after immortalization

Cell Death Differ. 2003 Sep;10(9):1025-31. doi: 10.1038/sj.cdd.4401273.

Abstract

Overexpression of SV40 T-antigen (SV40 T-Ag) has been widely used to overcome replicative senescence of human primary cells and to promote cell immortalization. However, in the case of certain cell types, such as preadipocytes, the differentiation process of immortalized cells is blocked by SV40 T-Ag expression. In this study, human telomerase reverse transcriptase (hTERT) and papillomavirus E7 oncoprotein (HPV-E7) genes were coexpressed in human preadipocytes to test whether this combination could maintain cell differentiation capacity after immortalization. We demonstrated that the HPV-E7/hTERT expressing preadipocytes displayed an indefinite life span. Interestingly, immortalized cells were diploid and presented no chromosomic alterations. These immortalized cells were able to accumulate and hydrolyze intracellular triglycerides and to express adipocyte markers. These data demonstrate, for the first time, that coexpression of hTERT and HPV-E7 in human preadipocytes allows cells not only to display an indefinite life span but also to retain their capacity to differentiate.

MeSH terms

  • Adipocytes / cytology*
  • Adipocytes / metabolism
  • Adult
  • Cell Differentiation
  • Cell Line, Transformed
  • Cell Transformation, Viral*
  • Cells, Cultured
  • DNA-Binding Proteins
  • Female
  • Gene Expression
  • Humans
  • Karyotyping
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / metabolism*
  • Papillomavirus E7 Proteins
  • Stem Cells / cytology*
  • Stem Cells / enzymology
  • Stem Cells / virology
  • Telomerase / metabolism*

Substances

  • DNA-Binding Proteins
  • Oncogene Proteins, Viral
  • Papillomavirus E7 Proteins
  • oncogene protein E7, Human papillomavirus type 16
  • Telomerase