A Novel Marine Drug, SZ-685C, Induces Apoptosis of MMQ Pituitary Tumor Cells by Downregulating miR-200c
A Novel Marine Drug, SZ-685C, Induces Apoptosis of MMQ Pituitary Tumor Cells by Downregulating miR-200c
复制标题
新型海洋药物SZ-685C通过下调miR-200c诱导MMQ垂体肿瘤细胞凋亡
DOI：
10.2174/0929867311320160007
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发表时间：
2013-05-01
影响因子：
4.1
通讯作者：
Zhu, Y. -H.
中科院分区：
文献类型：
--
作者：
Chen, C. -H.;Xiao, W. -W.;Zhu, Y. -H.
目的：从采自南海区中国海域的红树林内生真菌(编号1403)次生代谢产物中分离得到一种新的海洋药物SZ-685C，该真菌具有抑制某些肿瘤细胞增殖的作用。然而，其抗癌机制尚不清楚。本研究的目的是观察SZ-685C对垂体腺瘤细胞的作用，并探讨其作用机制。SZ-685C对该细胞系进行剂量递增，并用四甲基偶氮唑盐比色法检测细胞活力。采用Hoechst 33342、Annexin V-FITC/PI、TUNEL染色和流式细胞术检测不同浓度SZ-685C对细胞凋亡的影响。用RT-PCR和免疫印迹法检测SZ-685C对催乳素表达的影响。用定量RT-PCR方法检测SZ-685C刺激的MMQ细胞和垂体腺瘤组织中miR-200C的表达。结果：SZ-685C以剂量依赖方式抑制MMQ细胞的生长，但对大鼠脑垂体细胞(RPC)的毒性较小。SZ-685C对MMQ细胞和RPC的IC50分别为13.2+/-1.3 mm和49.1+/-11.5 mm，差异有统计学意义。随着SZ-685C浓度的升高，细胞凋亡率增加，催乳素(PRL)的表达水平受到抑制。但PRL基因表达水平无明显变化。此外，与RPC相比，miR-200C在MMQ细胞中表达上调，而在SZ-685C处理的MMQ细胞中miR-200C表达下调。此外，miR-200C的过表达减弱了SZ-685C诱导MMQ细胞凋亡的作用。因此，SZ-685C可能是治疗垂体腺瘤的一种有用的替代疗法。
Objective: We found a novel marine drug, SZ-685C, that was isolated from the secondary metabolites of a mangrove endophytic fungus (No. 1403) collected from the South China Sea, which has been reported to inhibit the proliferation of certain tumor cells. However, its anticancer mechanism remains unknown. The aims of this study were to observe the effectiveness of SZ-685C on pituitary adenoma cells and determine the underlying mechanisms of action.Methods: A rat prolactinoma cell line, MMQ, was used in this study. A dose escalation of SZ-685C was performed on this cell line, and cell viability was assessed using an MTT assay. Hoechst 33342, Annexin V-FITC/PI, TUNEL staining and flow cytometry were used to evaluate the extent of apoptosis at each concentration of SZ-685C. The effect of SZ-685C on prolactin expression was also evaluated using RT-PCR and immunoblotting. Quantitative RT-PCR was used to detect the expression of miR-200c in SZ-685C-stimulated MMQ cells and pituitary adenoma tissues. This miRNA was then overexpressed in MMQ cells via transfection of a miR-200c mimic to identify the mechanism underling the anti-tumor effect of SZ-685C.Results: SZ-685C inhibited MMQ cell growth in a dose-dependent manner but showed little toxicity toward rat pituitary cells (RPCs). The IC50s of SZ-685C in MMQ cells and RPCs were 13.2 +/- 1.3 mM and 49.1 +/- 11.5 mM, respectively, which was statistically significant. Increasing numbers of apoptotic cells were observed in response to escalating concentrations of SZ-685C, and the expression level of prolactin (PRL) was inhibited. Nevertheless, the level of PRL mRNA was unchanged. Additionally, miR-200c was upregulated in MMQ cells compared with RPCs, and downregulation of miR-200c was observed in SZ-685C-treated MMQ cells. Furthermore, the overexpression of miR-200c weakened the effect of SZ-685C-induced apoptosis of MMQ cells.Conclusions: Our results suggest that SZ-685C induces MMQ cell apoptosis in a miR-200c-dependent manner. Therefore, SZ-685C might be a useful alternative treatment for pituitary adenoma.