Coroglaucigenin induces senescence and autophagy in colorectal cancer cells
Coroglaucigenin induces senescence and autophagy in colorectal cancer cells
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Coroglaucigenin 诱导结直肠癌细胞衰老和自噬
DOI：
10.1111/cpr.12451
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发表时间：
2018-08-01
影响因子：
8.5
通讯作者：
Tan, Guang-Hong
中科院分区：
文献类型：
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作者：
Huang, Yong-Hao;Lei, Jing;Tan, Guang-Hong
目的：Coroglaucigenin（CGN）是本课题组从印度牛角瓜中分离得到的一种天然产物，具有潜在的抗癌活性。材料与方法：MTT法和BrdU法检测细胞活力和增殖。采用流式细胞术、SA-β-gal法、免疫印迹法和免疫荧光法检测CGN诱导的细胞凋亡、衰老和自噬。采用Western blotting、siRNA转染和免疫共沉淀等方法研究CGN诱导衰老和自噬的机制。CGN和氯喹联合治疗的抗肿瘤活性在小鼠肿瘤模型中观察。结果：我们证明CGN抑制大肠癌细胞在体外和体内的增殖。我们发现CGN对细胞增殖的抑制作用不依赖于细胞凋亡，但与结直肠癌细胞的细胞周期阻滞和衰老有关。值得注意的是，CGN诱导保护性自噬，其减弱CGN介导的细胞增殖。功能研究表明，CGN破坏了Hsp 90与CDK 4和Akt的结合，导致CDK 4降解和Akt去磷酸化，最终分别导致衰老和自噬。CGN和氯喹的联合治疗导致增强的抗肿瘤作用在vivo.Conclusions：我们的研究结果表明，CGN诱导大肠癌细胞的衰老和自噬，并表明将其与自噬抑制剂相结合可能是一种新的策略，适合CGN介导的抗癌治疗。
Objectives: Coroglaucigenin (CGN), a natural product isolated from Calotropis gigantean by our research group, has been identified as a potential anti-cancer agent. However, the molecular mechanisms involved remain poorly understood.Materials and methods: Cell viability and cell proliferation were detected by MTT and BrdU assays. Flow cytometry, SA-beta-gal assay, western blotting and immunofluorescence were performed to determine CGN-induced apoptosis, senescence and autophagy. Western blotting, siRNA transfection and coimmunoprecipitation were carried out to investigate the mechanisms of CGN-induced senescence and autophagy. The anti-tumour activities of combination therapy with CGN and chloroquine were observed in mice tumour models.Results: We demonstrated that CGN inhibits the proliferation of colorectal cancer cells both in vitro and in vivo. We showed that the inhibition of cell proliferation by CGN is independent of apoptosis, but is associated with cell-cycle arrest and senescence in colorectal cancer cells. Notably, CGN induces protective autophagy that attenuates CGN-mediated cell proliferation. Functional studies revealed that CGN disrupts the association of Hsp90 with both CDK4 and Akt, leading to CDK4 degradation and Akt dephosphorylation, eventually resulting in senescence and autophagy, respectively. Combination therapy with CGN and chloroquine resulted in enhanced anti-tumour effects in vivo.Conclusions: Our results demonstrate that CGN induces senescence and autophagy in colorectal cancer cells and indicate that combining it with an autophagy inhibitor may be a novel strategy suitable for CGN-mediated anti-cancer therapy.