@article{oai:repo.qst.go.jp:00045853,
 author = {Nagai, Ken-ichi and Ishii, Hideshi and Saito, Toshiyuki and Nagano, Hiroaki and Sekimoto, Mitsugu and Doki, Yuichiro and Mori, Masaki and et.al and 齋藤 俊行},
 issue = {2},
 journal = {Biochemical and Biophysical Research Communications},
 month = {Apr},
 note = {BACKGROUND: We recently reported that gastrointestinal (GI) cancer cells can be reprogrammed to a pluripotent state by the ectopic expression of defined embryonic stem (ES)-like transcriptional factors. The induced pluripotent cancer (iPC) cells from GI cancer were sensitized to chemotherapeutic agents and differentiation-inducing treatment during a short-term culture, although a phenotype induced by long-term culture needs to be studied. METHODS: A long-term cultured (Lc)-iPC cells were produced in GI cancer cell lines by virus-mediated introduction of four ES-like genes-c-MYC, SOX2, OCT3/4, and KLF4-followed by a culture more than three months after iPC cells induction. An acquired state was studied by expression of immature-related surface antigens, Tra-1-60, Tra-1-81, Tra-2-49, and Ssea-4; and epigenetic trimethyl modification at lysine 4 of histone H3. Sensitivity to chemotherapeutic agents and tumorigenicity were studied in Lc-iPC cells. RESULTS: Whereas the introduction of defined factors of iPC cells once induced an immature state and sensitized cells to therapeutic reagents, the endogenous expression of the ES-like genes except for activated endogenous c-MYC was down-regulated in a long-term culture, suggesting a high magnitude of the reprogramming induction by defined factors and the requirement of therapeutic maintenance in Lc-iPC cells from cholangiocellular carcinoma HuCC-T1 cells, which harbor TP53(R175H) and KRAS(G12D). The Lc-iPC cells showed resistance to 5-fluorouracil in culture, and high tumorigenic ability with activated endogenous c-MYC in immunodeficient mice. CONCLUSION: The Lc-iPC cells from HuCC-T1 might be prone to an undesirable therapeutic response because of an association with the activated endogenous c-MYC. To consider the possible therapeutic approach in GI cancer, it would be necessary to develop a predictive method for evaluating the improper reprogramming-associated aggressive phenotype of iPC cells.},
 pages = {258--263},
 title = {Long-term culture following ES-like gene-induced reprogramming elicits an aggressive phenotype in mutated cholangiocellular carcinoma cells.},
 volume = {395},
 year = {2010}
}