真菌次级代谢产物rasfonin促进舒尼替尼(Sunitinib)诱导的肾癌细胞自噬和凋亡

【目的】明确真菌次级代谢产物rasfonin影响舒尼替尼(Sunitinib,ST)诱导的肾癌细胞自噬和凋亡作用机理。【方法】应用MTS(Methanethiosulfonate assay)和克隆形成实验检测rasfonin和舒尼替尼对肾癌细胞ACHN活性和增殖的影响,通过透射电子显微镜、荧光显微镜、蛋白免疫印迹、免疫荧光方法检测rasfonin和舒尼替尼处理的ACHN细胞自噬、凋亡情况和相关信号通路的变化。【结果】Rasfonin和舒尼替尼能够抑制肾癌细胞ACHN活性和细胞增殖;免疫印迹结果表明,两者均可以引起caspase依赖的凋亡。在rasfonin存在的情况下,不仅舒尼替尼所引起的凋亡和细胞活性丢失明显增加,而且其诱导的自噬流显著提高。无论是rasfonin还是舒尼替尼均明显地抑制哺乳雷帕霉素靶蛋白m TOR(Mammal target of rapamycin)磷酸化,而两者均能促进细胞外调节蛋白激酶(Extracellular regulated protein kinases,ERK)活性增加。【结论】rasfonin促进了舒尼替尼诱导的细胞自噬和凋亡,提高了舒尼替尼抑制肾癌细胞增殖的活性。

Fungal secondary metabolite rasfonin enhances sunitinib-induced autophagy and apoptosis in renal carcinoma cells

Objective] We studied the regulatory role of rasfonin in mediating sunitinib induced autophagy and apoptosis.Methods] We used both methanethiosulfonate assay and colony growth assay to detect the cell viability and proliferation. In addition, we used electronic and fluorescence microscopy to examine the formation of autophagosome, as well as carried out immunofluorescence or immunoblotting to determine autophagy and apoptosis.Results] Both rasfonin and sunitinib could induce autophagy and caspase-dependent apoptosis in renal carcinoma cells. Notably, low dose of rasfonin enhanced sunitinib-dependent autophagy and apoptosis, meanwhile sunitinib and rasfonin synergistically inhibited cell viability. In addition, both sunitinib and rasfonin inhibited the phosphorylation of mammal target of rapamycin and increased the activity of extracellular regulated protein kinases.Conclusion] Rasfonin promotes sunitinib-induced autophagy and caspase dependent apoptosis, and strengthens the cytotoxic effect of sunitinib in renal carcinoma cells.