Open AccessEnrichment of ovarian cancer stem‐like cells is associated with epithelial to mesenchymal transition through an miRNA‐activated AKT pathway
Author(s) -
Luo X.,
Dong Z.,
Chen Y.,
Yang L.,
Lai D.
Publication year - 2013
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/cpr.12038
Subject(s) - epithelial–mesenchymal transition , pi3k/akt/mtor pathway , cancer research , cancer stem cell , ovarian cancer , transfection , mesenchymal stem cell , chemistry , biology , protein kinase b , cancer cell , microrna , stem cell , microbiology and biotechnology , cell culture , metastasis , cancer , signal transduction , biochemistry , gene , genetics
Abstract Objectives Evidence has indicated that ovarian epithelial cancer‐type cells under serum‐free culture conditions can form spheroid cells and exhibit characteristics expected of cancer stem‐like cells ( CSC s). However, the mechanism by which differentiated ovarian cancer cells acquire stem‐cell properties during CSC enrichment has needed to be elucidated. Recent studies have demonstrated that induction of epithelial to mesenchymal transition ( EMT ) can generate CSC s and be associated with tumour aggressiveness and metastasis. Materials and methods Ovarian epithelial cancer cell lines, SKOV3 and HO8920, were cultured for spheroid cells and adherent cells. CSC enrichment was investigated using MTT assay, flow cytometery and qRT‐PCR and expression level of PI3K/AKT pathway components was analysed by western blotting. Results Compared to adherent cells, the spheroid cells expressed mesenchymal markers highly and exhibited significantly more motility; we also observed increases in phosphate AKT1 levels in the spheroid cells. Moreover, transfection of miR‐20a or miR‐200c led to corresponding reduction in endogenous PTEN protein, while AKT1 and phosphate AKT1 levels were upregulated in miRNAs‐transfected cells. Finally, PI3K/AKT pathway inhibitor LY294002 reduced expressions of mesenchymal markers and stem‐cell gene activity in spheroid cells, enhancing sensitivity of spheroid cells to paclitaxel treatment. Conclusions Our findings demonstrate that EMT contributed to enrichment of ovarian CSC s in vitro , making EMT targeting in epithelial ovarian cancer a novel therapeutic option.