The identification of the biological characteristics of human ovarian cancer stem cells

OBJECTIVE: Identifying the bio - logical characteristics of previously screened ovarian cancer cell line HO8910-derived stem cells. MATERIALS AND METHODS: The pre-screen - ing of ovarian cancer cell line HO8910-derived stem cells were subcultured (HO8910 cells were used as a control group) in serum-free medium. Firstly, the capacities of forming spheroids and self-renewal were observed. Then ovarian cancer stem cells (CSCs) were seeded in medium con - taining serum and cultured to observe the changes in their ability to differentiate. The stem cell-specific markers were also tested. Secondly, we tested the sensitivity of stem cells to cisplatin, doxorubicin, and mitoxantrone using drug sus - ceptibility test. Finally, we inoculated the ovarian CSCs after passaging from culturing in serum- free media to NOD/SCID (non-obese diabetic/se - vere combined immunodeficient mice) mice in or - der to observe the tumorigenicity in vivo . RESULTS: Ovarian CSCs cultured in serum-free medium are capable of forming stable passaged cells spheres and have strong ability of self-re - newal and differentiation. Under the condition of serum-free medium culture, the expression levels of CDl33+, CD117+, ABCG2, Nanog, Oct4, and BCRP in ovarian cancer stem cell are significant - ly higher than the counterparts in HO8910 cells. With the increase of the ability of differentiation, the stem cell marker expression levels reduced. While the differentiation, potential marker-E- cadherin expression levels were significantly low - er than the control group. With the increase of the ability to differentiate, E-cadherin expression lev - el was increased. Ovarian CSCs have significant resistance to cisplatin, doxorubicin, and mitox - antrone. NOD/SCID nude mice experiments showed that ovarian cancer stem cell tumori - genicity was significantly higher than control cells and has a continuous tumorigenicity. CONCLUSIONS: Comparing ovarian CSCs derived from HO8910 to HO8910 cells, the stem cells have significantly enhanced abilities of self-renewal, differentiation, in vivo tumori - genicity, highly expressed stem cell genes, and multidrug resistance.