FTY720诱导卵巢癌细胞发生可逆性白噬及抗癌机制的探索

目的：体外观察FTY720对人卵巢癌细胞的生长抑制效应，探讨其独特的抗癌效应。方法：采用Mr丌法检测不同浓度（2．5，5，7．5，10，12．5，15μmol／L）FTY720作用24、48、72h后，对人卵巢癌OV2008和SKOV3细胞的生长抑制效应。以不同密度（亚饱和、饱和、过饱和）接种OV2008和SKOV3细胞，MTＴ及相差显微镜下检测细胞的形态学，并观察FTY720的抗卵巢癌效应与细胞接种密度间的关系。相差显微镜下观察FTY720诱导的可逆性自噬现象。Westernblot法检测自噬效应分子LC3的表达变化。MTT及Westernblot法分别检测mTOR抑制剂雷帕霉素（RA）、PP2A抑制剂冈田酸（OA）对FTY720抗癌效应的影响。结果：FTY720对卵巢癌OV2008、SKOV3细胞的生长抑制作用呈剂量时间依赖性，且其诱导的卵巢癌细胞毒性效应具有细胞接种密度依赖性。FTY720导致的卵巢癌细胞自噬具有可逆转性特点。RA不影响FTY720的抗卵巢癌效应，而OA则可协同FTY720的抗癌效应。结论：FTY720抑制卵巢癌细胞生长具有剂量时间依赖性，FTY720诱导的细胞密度依赖性抗癌效应、可逆性自噬现象、非mTOR途径依赖，以及其与PP2A途径发生协同抗癌效应等特点提示FTY720独特模式的抗卵巢癌效应。

Reversible autophagy triggered by FTY720 and the exploration of its anticancer mecha-nism against human ovarian cancer cells

Objective：To investigate the cytotoxicity and unique anticancer effect of FTY720 against human ovarian cancer cells. Methods：The human ovarian cancer OV2008 and SKOV3 cells were cultured with different concentration （2.5,5,7.5,10,12.5,15 μmol/L） of FTY720 for indicated time （24,48,72h）. The anticancer activity of FTY720 was measured by MTT. The correlation between FTY720-induced cytotoxicity and cell-seeding density was exam- ined by MTF, further confirmed by morphological alteration with phase-contrast microscope. The reversible phenomenon of FTY720-triggered autophagy was examined by phase-contrast micro- scope and further confirmed by molecular change with Western blot. The influence of signal pathway mTOR or PP2A on the FTY720-induced antieancer effect was examined by MTT and Western blot in the presence or absence of Rapamyein （mTOR inhibitor） or Okadaic acid （OA, PP2A inhibitor）. Results ： FTY720-induced cytotoxicity against human ovarian cancer cell OV2008 and SKOV3 was dose-and time-dependent,also the obvious correlation between cyto-toxicity and cell-seeing density was found. The reversible phenomenon of FTY720-triggerd auto- phagy could be examined by morphological change and molecular alteration. The anticancer effect of FTY720 couldn＇t be influenced by rapamycin but was synergistically enhanced in the presence of OA. Con~lusion：FTY720 can inhibit proliferation of human ovarian cancer cells in a dose-and time-dependent manner, further, the characteristics of FTY720-induced effect such as the obvious correlation between cytotoxicity and cell-seeding density, reversible autophagy as well as the mechanism of roTOR-independent but synergism with PP2A pathway indicate FTY720 can exert its unique anticancer activity against human ovarian cancer.