Syntaxin 17调控细胞自噬对胆管癌干细胞生物学特性的影响和机制研究

Autophagy plays a significant role in maintaining malignant biological behavior of cancer stem cells, but so far there is no any research of autophagy in cholangiocarcinoma stem cells(CSCs). On the basis of identification of CSCs, we found that autophagy was activated and the expression of Syntaxin17 is higher in the CSCs, which is the key protein for the autophagosome-lysosome fusion. The Autophagy was significant inhibited after si-Syntaxin17. However, the role and molecular mechanism of Syntaxin 17 for the cholangicarcinoma stem cell properties by regulation of the cell autophagy is still unknown. To answer these questions, this project is proposed: to detect the different stages of autophagy in CSCs, clarify the relationship between the autophagy and cholangicarcinoma stem cell properties; to detect changes of autophagy and CSCs malignant biological behavior after intervening in Syntaxin17; to elucidate the molecular mechanism of Syntaxin17 impacting autophagy and CSCs characteristics by affect autophagosome-lysosome fusion; and finally to clarify the up-stream regulatory mechanism of Syntaxin17 combining with epigenetic regulation. This project is expected to clarify the potential mechanism of CSCs autophagy and the long-term maintaining malignant behavior, and provide new ideas for the targeted therapy of cholangiocarcinoma.

细胞自噬在肿瘤干细胞恶性生物学行为的维持中发挥重要作用，但至今未见胆管癌干细胞细胞自噬的研究。我们前期分选、鉴定到胆管癌干细胞，发现细胞自噬在胆管癌干细胞中增强表达；自噬溶酶体形成关键蛋白Syntaxin17在胆管癌干细胞中高表达，干预后其细胞自噬被显著抑制。但Syntaxin17调控的细胞自噬在胆管癌干细胞恶性生物学中的作用和机制仍然未彻底阐明清楚。本项目拟进一步阐明胆管癌干细胞的自噬现象，探讨细胞自噬和胆管癌干细胞恶性生物学行为的关系；干预Syntaxin17后检测胆管癌干细胞细胞自噬和恶性生物学行为的变化；阐明Syntaxin17影响自噬溶酶体形成过程的分子机制；探讨Syntaxin17上游调控及其本身的表观遗传学调控机制。本项目有望阐明胆管癌干细胞的细胞自噬现象及其恶性行为长期维持的潜在机制，为其靶向治疗提供新思路。

细胞自噬在肿瘤干细胞恶性生物学行为的维持中发挥重要作用，但至今未见胆管癌干细胞细胞自噬的研究。我们首先通过胆管癌临床样本的全外显子测序鉴定出存在较高突变的分子Syntaxin17。之后我们分选、鉴定到胆管癌干细胞，发现细胞自噬在胆管癌干细胞中增强表达；自噬溶酶体形成关键蛋白Syntaxin17在胆管癌干细胞中高表达，干预后其细胞自噬被显著抑制，并且胆管癌干细胞在耐药性、侵袭迁移、增殖等方面的能力得到明显抑制。我们研究出Syntaxin17分子是通过影响SNARE复合体的结合来影响自噬体与溶酶体的融合进而影响自噬。之后我们通过高通量方法寻找到了Syntaxin17的上游分子Let-7c，发现其通过对Syntaxin17分子进行抑制来抑制胆管癌干细胞的恶性能力。