Takeuchi Masao, Takeuchi Kikuko, Kohara Arihiro, Satoh Motonobu, Shioda Setsuko, Ozawa Yutaka, Ohtani Azusa, Morita Keiko, Hirano Takashi, Terai Masanori, Umezawa Akihiro, Mizusawa Hiroshi
Division of Bioresources, National Institute of Biomedical Innovation, Osaka, Japan.
In Vitro Cell Dev Biol Anim. 2007 Mar-Apr;43(3-4):129-38. doi: 10.1007/s11626-007-9021-9. Epub 2007 May 21.
Human mesenchymal stem cells (hMSCs) are expected to be an enormous potential source for future cell therapy, because of their self-renewing divisions and also because of their multiple-lineage differentiation. The finite lifespan of these cells, however, is a hurdle for clinical application. Recently, several hMSC lines have been established by immortalized human telomerase reverse transcriptase gene (hTERT) alone or with hTERT in combination with human papillomavirus type 16 E6/E7 genes (E6/E7) and human proto-oncogene, Bmi-1, but have not so much been characterized their karyotypic stability in detail during extended lifespan under in vitro conditions. In this report, the cells immortalized with the hTERT gene alone exhibited little change in karyotype, whereas the cells immortalized with E6/E7 plus hTERT genes or Bmi-1, E6 plus hTERT genes were unstable regarding chromosome numbers, which altered markedly during prolonged culture. Interestingly, one unique chromosomal alteration was the preferential loss of chromosome 13 in three cell lines, observed by fluorescence in situ hybridization (FISH) and comparative-genomic hybridization (CGH) analysis. The four cell lines all maintained the ability to differentiate into both osteogenic and adipogenic lineages, and two cell lines underwent neuroblastic differentiation. Thus, our results were able to provide a step forward toward fulfilling the need for a sufficient number of cells for new therapeutic applications, and substantiate that these cell lines are a useful model for understanding the mechanisms of chromosomal instability and differentiation of hMSCs.
人间充质干细胞（hMSCs）因其自我更新分裂能力以及多向分化能力，有望成为未来细胞治疗的巨大潜在来源。然而，这些细胞的有限寿命是临床应用的一个障碍。最近，通过单独的人端粒酶逆转录酶基因（hTERT）或hTERT与16型人乳头瘤病毒E6/E7基因（E6/E7）以及人类原癌基因Bmi-1组合，已经建立了几种hMSC细胞系，但在体外延长寿命期间，尚未对其核型稳定性进行详细表征。在本报告中，仅用hTERT基因永生化的细胞在核型上几乎没有变化，而用E6/E7加hTERT基因或Bmi-1、E6加hTERT基因永生化的细胞在染色体数目方面不稳定，在长期培养过程中发生了明显改变。有趣的是，通过荧光原位杂交（FISH）和比较基因组杂交（CGH）分析观察到，在三个细胞系中一个独特的染色体改变是13号染色体的优先丢失。这四个细胞系均保持了向成骨和成脂谱系分化的能力，并且两个细胞系发生了神经母细胞分化。因此，我们的结果能够朝着满足新治疗应用所需足够数量细胞的需求迈进一步，并证实这些细胞系是理解hMSCs染色体不稳定性和分化机制的有用模型。
