Oo Aung Ko Ko, Calle Anna Sanchez, Nair Neha, Mahmud Hafizah, Vaidyanath Arun, Yamauchi Junya, Khayrani Aprilliana Cahya, Du Juan, Alam Md Jahangir, Seno Akimasa, Mizutani Akifumi, Murakami Hiroshi, Iwasaki Yoshiaki, Chen Ling, Kasai Tomonari, Seno Masaharu
Department of Medical Bioengineering, Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan; Department of Biotechnology, Mandalay Technological University, Mandalay, Myanmar.
Division of Molecular and Cellular Medicine, National Cancer Center Research Institute, Tokyo 104-0045, Japan.
Transl Oncol. 2018 Jun;11(3):653-663. doi: 10.1016/j.tranon.2018.03.001. Epub 2018 Apr 2.
Previously, we have succeeded in converting induced pluripotent stem cells (iPSCs) into cancer stem cells (CSCs) by treating the iPSCs with conditioned medium of Lewis lung carcinoma (LLC) cells. The converted CSCs, named miPS-LLCcm cells, exhibited the self-renewal, differentiation potential, and potential to form malignant tumors with metastasis. In this study, we further characterized miPS-LLCcm cells both in vivo and in vitro. The tumors formed by subcutaneous injection showed the structures with pathophysiological features consisting of undifferentiated and malignant phenotypes generally found in adenocarcinoma. Metastasis in the lung was also observed as nodule structures. Excising from the tumors, primary cultured cells from the tumor and the nodule showed self-renewal, differentiation potential as well as tumor forming ability, which are the essential characters of CSCs. We then characterized the epigenetic regulation occurring in the CSCs. By comparing the DNA methylation level of CG rich regions, the differentially methylated regions (DMRs) were evaluated in all stages of CSCs when compared with the parental iPSCs. In DMRs, hypomethylation was found superior to hypermethylation in the miPS-LLCcm cells and its derivatives. The hypo- and hypermethylated genes were used to nominate KEGG pathways related with CSC. As a result, several categories were defined in the KEGG pathways from which most related with cancers, significant and high expression of components was PI3K-AKT signaling pathway. Simultaneously, the AKT activation was also confirmed in the CSCs. The PI3K-Akt signaling pathway should be an important pathway for the CSCs established by the treatment with conditioned medium of LLC cells.
此前，我们已成功通过用Lewis肺癌（LLC）细胞的条件培养基处理诱导多能干细胞（iPSC），将其转化为癌症干细胞（CSC）。转化后的CSC，命名为miPS-LLCcm细胞，表现出自我更新、分化潜能以及形成具有转移能力的恶性肿瘤的潜能。在本研究中，我们进一步在体内和体外对miPS-LLCcm细胞进行了表征。皮下注射形成的肿瘤显示出具有病理生理特征的结构，由腺癌中常见的未分化和恶性表型组成。肺部转移也表现为结节结构。从肿瘤中切除后，肿瘤和结节的原代培养细胞显示出自我更新、分化潜能以及肿瘤形成能力，这些都是CSC的基本特征。然后，我们对CSC中发生的表观遗传调控进行了表征。通过比较富含CG区域的DNA甲基化水平，与亲代iPSC相比，在CSC的所有阶段评估了差异甲基化区域（DMR）。在DMR中，发现miPS-LLCcm细胞及其衍生物中低甲基化优于高甲基化。低甲基化和高甲基化基因被用于提名与CSC相关的KEGG通路。结果，在KEGG通路中定义了几个类别，其中大多数与癌症相关，PI3K-AKT信号通路的成分显著且高表达。同时，在CSC中也证实了AKT的激活。PI3K-Akt信号通路应该是用LLC细胞条件培养基处理建立的CSC的重要通路。
