Maintenance of Differentiation Potential of Human Bone Marrow Mesenchymal Stem Cells Immortalized by Human Telomerase Reverse Transcriptase Gene Despite [Corrected] Extensive Proliferation

Biochem Biophys Res Commun. 2005 Jan 21;326(3):527-38. doi: 10.1016/j.bbrc.2004.11.059.

Abstract

Human bone marrow mesenchymal stem cells (hMSC) represent a population of stem cells that are capable of differentiation into multiple lineages. However, these cells exhibit senescence-associated growth arrest and phenotypic changes during long-term in vitro culture. We have recently demonstrated that overexpression of human telomerase reverse transcriptase (hTERT) in hMSC reconstitutes telomerase activity and extends life span of the cells [Nat. Biotechnol. 20 (2002) 592]. In the present study, we have performed extensive characterization of three independent cell lines derived from the parental hMSC-TERT cell line based on different plating densities during expansion in culture: 1:2 (hMSC-TERT2), 1:4 (hMSC-TERT4), and 1:20 (hMSC-TERT20). The 3 cell lines exhibited differences in morphology and growth rates but they all maintained the characteristics of self-renewing stem cells and the ability to differentiate into multiple mesoderm-type cell lineages: osteoblasts, adipocytes, chondrocytes, and endothelial-like cells over a 3-year period in culture. Also, surface marker studies using flow cytometry showed a pattern similar to that known from normal hMSC. Thus, telomerization of hMSC by hTERT overexpression maintains the stem cell phenotype of hMSC and it may be a useful tool for obtaining enough number of cells with a stable phenotype for mechanistic studies of cell differentiation and for tissue engineering protocols.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Marrow Cells / cytology
  • Bone Marrow Cells / physiology*
  • Cell Differentiation / physiology*
  • Cell Division / physiology
  • DNA-Binding Proteins
  • Gene Transfer Techniques
  • Humans
  • Stem Cells / cytology
  • Stem Cells / physiology*
  • Telomerase / genetics
  • Telomerase / metabolism*

Substances

  • DNA-Binding Proteins
  • TERT protein, human
  • Telomerase