Int J Med Sci 2014; 11(11):1154-1160. doi:10.7150/ijms.8281

Short Research Communication

Heterogeneity of Osteosarcoma Cell Lines Led to Variable Responses in Reprogramming

Pei Feng Choong1,2*, Hui Xin Teh2*, Hoon Koon Teoh1, Han Kiat Ong2, Kong Bung Choo2, Shigeki Sugii3,4, Soon Keng Cheong1,2✉, Tunku Kamarul5

1. MAKNA Cancer Research Institute, Kuala Lumpur, Malaysia;
2. Faculty of Medicine and Health Sciences, University Tunku Abdul Rahman (UTAR), Selangor, Malaysia;
3. Fat Metabolism and Stem Cell Group, Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, 138667, Singapore;
4. Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore;
5. Tissue Engineering Group, National Orthopaedic Centre of Excellence for Research and Learning, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
* These authors contributed equally to the work.

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See for full terms and conditions.
Choong PF, Teh HX, Teoh HK, Ong HK, Choo KB, Sugii S, Cheong SK, Kamarul T. Heterogeneity of Osteosarcoma Cell Lines Led to Variable Responses in Reprogramming. Int J Med Sci 2014; 11(11):1154-1160. doi:10.7150/ijms.8281. Available from

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Four osteosarcoma cell lines, Saos-2, MG-63, G-292 and U-2 OS, were reprogrammed to pluripotent state using Yamanaka factors retroviral transduction method. Embryonic stem cell (ESC)-like clusters started to appear between 15 to 20 days post transduction. Morphology of the colonies resembled that of ESC colonies with defined border and tightly-packed cells. The reprogrammed sarcomas expressed alkaline phosphatase and pluripotency markers, OCT4, SSEA4, TRA-1-60 and TRA-1-81, as in ESC up to Passage 15. All reprogrammed sarcomas could form embryoid body-like spheres when cultured in suspension in a low attachment dish for up to 10 days. Further testing on the directed differentiation capacity of the reprogrammed sarcomas showed all four reprogrammed sarcoma lines could differentiate into adipocytes while reprogrammed Saos-2-REP, MG-63-REP and G-292-REP could differentiate into osteocytes. Among the 4 osteosarcoma cell lines, U-2 OS reported the highest transduction efficiency but recorded the lowest reprogramming stability under long term culture. Thus, there may be intrinsic differences governing the variable responses of osteosarcoma cell lines towards reprogramming and long term culture effect of the reprogrammed cells. This is a first report to associate intrinsic factors in different osteosarcoma cell lines with variable reprogramming responses and effects on the reprogrammed cells after prolonged culture.

Keywords: reprogramming, cancer cells, pluripotency, embryonic stem cells, osteosarcoma, heterogeneity.