“Ins” and “Outs” of mesenchymal stem cell osteogenesis in regenerative medicine

Core Tip

Core tip: When human telomerase reverse transcriptase (hTERT) transformed human mesenchymal stem cells (hMSCs) are used to prolong replicative potential and osteogenic differentiation, consideration should be given to using lower population doubling hTERT-transformed hMSCs to avoid potential oncogenesis. An inducible hTERT system may also avoid oncogenic transformation. Demonstration of in vivo bone forming capacity of hTERT-transformed cells should be used as standard in determining osteogenic differentiation of such cells rather than in vitro culture mineralization; the CD146 marker may be a suggested surface marker for hTERT-transformed hMSCs that may have the capacity to form bone in vivo. Native ECM from early population doubling hMSCs or hMSCs from a younger source may be best when seeking to extend the proliferative and differentiating potential of hMSCs from either young or older sources.