Chick Embryo Extract Demethylates Tumor Suppressor Genes in Osteosarcoma Cells
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Epigenetics is the study of changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. It is widely accepted that cancer has genetic and epigenetic origins. The idea of epigenetic reprogramming of cancer cells by an embryonic microenvironment possesses potential interest from the prospect of both basic science and potential therapeutic strategies. Chick embryo extract (CEE) has been used for the successful expansion of many specific stem cells and has demonstrated the ability to facilitate DNA demethylation.
The current study was conducted to compare the status of DNA methylation in highly metastatic and less metastatic osteosarcoma cells and to investigate whether CEE may affect the epigenetic regulation of tumor suppressor genes and thus change the metastatic phenotypes of highly metastatic osteosarcoma cells.
K7M2 murine OS cells were treated with CEE to determine its potential effect on DNA methylation, cell apoptosis, and invasion capacity.
Our current results suggest that the methylation status of tumor suppressor genes (p16, p53, and E-cadherin) is significantly greater in highly metastatic mouse ostoesarcoma K7M2 cells in comparison with less metastatic mouse osteosarcoma K12 cells. CEE treatment of K7M2 cells caused demethylation of p16, p53, and E-cadherin genes, upregulated their expression, and resulted in the reversion of metastatic phenotypes in highly metastatic osteosarcoma cells.
CEE may promote the reversion of metastatic phenotypes of osteosarcoma cells and can be a helpful tool to study osteosarcoma tumor reversion by epigenetic reprogramming.
Demethylation of tumor suppressor genes in osteosarcoma may represent a novel strategy to diminish the metastatic potential of this neoplasm. Further studies, both in vitro and in vivo, are warranted to evaluate the clinical feasibility of this approach as an adjuvant to current therapy.
KeywordsOsteosarcoma Tumor Suppressor Gene Cancer Stem Cell Osteosarcoma Cell Metastatic Phenotype
We acknowledge the support of The Pittsburgh Foundation and the Houy family in loving memory of Jon Houy.
- 5.Bielack SS, Kempf-Bielack B, Delling G, Exner GU, Flege S, Helmke K, Kotz R, Salzer-Kuntschik M, Werner M, Winkelmann W, Zoubek A, Jurgens H, Winkler K. Prognostic factors in high-grade osteosarcoma of the extremities or trunk: an analysis of 1,702 patients treated on neoadjuvant cooperative osteosarcoma study group protocols. J Clin Oncol. 2002;20:776–790.PubMedCrossRefGoogle Scholar
- 15.Ferrari S, Smeland S, Mercuri M, Bertoni F, Longhi A, Ruggieri P, Alvegard TA, Picci P, Capanna R, Bernini G, Muller C, Tienghi A, Wiebe T, Comandone A, Bohling T, Del Prever AB, Brosjo O, Bacci G, Saeter G. Neoadjuvant chemotherapy with high-dose Ifosfamide, high-dose methotrexate, cisplatin, and doxorubicin for patients with localized osteosarcoma of the extremity: a joint study by the Italian and Scandinavian Sarcoma Groups. J Clin Oncol. 2005;23:8845–8852.PubMedCrossRefGoogle Scholar
- 26.Kiss NB, Geli J, Lundberg F, Avci C, Velazquez-Fernandez D, Hashemi J, Weber G, Hoog A, Ekstrom TJ, Backdahl M, Larsson C. Methylation of the p16INK4A promoter is associated with malignant behavior in abdominal extra-adrenal paragangliomas but not pheochromocytomas. Endocr Relat Cancer. 2008;15:609–621.PubMedCrossRefGoogle Scholar
- 30.Meyers PA, Schwartz CL, Krailo MD, Healey JH, Bernstein ML, Betcher D, Ferguson WS, Gebhardt MC, Goorin AM, Harris M, Kleinerman E, Link MP, Nadel H, Nieder M, Siegal GP, Weiner MA, Wells RJ, Womer RB, Grier HE. Osteosarcoma: the addition of muramyl tripeptide to chemotherapy improves overall survival—a report from the Children’s Oncology Group. J Clin Oncol. 2008;26:633–638.PubMedCrossRefGoogle Scholar
- 33.Pajtler K, Bohrer A, Maurer J, Schorle H, Schramm A, Eggert A, Schulte JH. Production of chick embryo extract for the cultivation of murine neural crest stem cells. J Vis Exp. 2010.Google Scholar
- 35.Rajasingh J, Lambers E, Hamada H, Bord E, Thorne T, Goukassian I, Krishnamurthy P, Rosen KM, Ahluwalia D, Zhu Y, Qin G, Losordo DW, Kishore R. Cell-free embryonic stem cell extract-mediated derivation of multipotent stem cells from NIH3T3 fibroblasts for functional and anatomical ischemic tissue repair. 2008;102:e107–117.Google Scholar