Notch信号通路介导新m/z6449Da活性肽在调控胃腺癌凋亡及增殖中的作用及其分子机制研究

Gastric adenocarcinoma accounts for 95% of all gastric cancers and lacks a peptide antitumor drug with strong biological activity and specific target. High expression of Notch-1/Jagged-1 in the Notch signaling pathway are closely related to the low survival of patients with gastric adenocarcinoma.Our previous studies found that 6449 Da anti-cancer active peptide was a specific non-inflammatory biomarker in the serum of patients with gastric adenocarcinoma which was lowly expressed at high frequency in gastric adenocarcinoma tissues, promoting apoptosis and inhibiting proliferation of gastric adenocarcinoma cells. Moreover,our preliminary data suggest that the 6449Da active peptide functional fragment WSGC peptide localized on the surface of the cell membrane may relatively specifically promote apoptosis and inhibit proliferation of gastric adenocarcinoma cells via Notch signaling pathway. However, the exact molecular mechanism of Notch signaling pathway mediating apoptosis and proliferation and the corresponding downstream regulatory network of interaction with Notch remain unclear.Taking advantage of 6449Da active peptide and primary cultured gastric adenocarcinoma cells as the research objects ,this study will continue to further explore, clarify and confirm the exact molecular mechanism and corresponding downstream regulatory network of the "pro-apoptotic and anti-proliferative" of the shortest functional fragment of WSGC peptide mediated by Notch signaling pathway in a series of in vivo and in vitro experiments, via experimental methods such as the EdU cell proliferation , flow cytometry for apoptosis,co-immunoprecipitation, protein mass spectrum , immunofluorescence laser confocal ,tumor-bearing animal, tumor-metastatic animal and patient-derived tumor xenograft(PDTX) model.Completion of this study will provide a theoretical basis on the advent of a new anti-gastric adenocarcinoma peptide drug and the promotion of gastric adenocarcinoma prevention and treatment.

胃腺癌在我国高发，缺乏生物活性强且靶点专一的多肽类抗肿瘤药物。Notch-1/Jagged-1高表达与胃腺癌生存预后密切相关。前期研究及预实验结果示：组织中高频低表达的6449Da抗癌活性肽是胃腺癌血清特异性非炎症性生物标志物；定位于细胞膜表面的6449肽功能片段WSGC肽可能通过Notch通路介导相对特异地促凋亡、抑增殖。而Notch通路介导凋亡增殖的确切分子机制及与Notch互作的下游调控网络不明。本项目将承前启后，以6449Da活性肽和原代胃腺癌细胞为研究对象，拟在一系列体内和体外实验中，通过EdU细胞增殖、流式细胞凋亡、免疫共沉淀、蛋白质谱、激光共聚焦、动物荷瘤、转移瘤及PDTX模型等方法，进一步探寻、阐明并确证Notch通路介导WSGC肽最短功能片段“促凋亡、抑增殖”的确切分子机制及其调控网络。项目的完成将对催生一种新型抗胃腺癌多肽药物的问世及促进胃腺癌的防治工作提供理论基础。

胃腺癌在我国高发，传统化疗药物不良反应多，而多肽类药物具有生物活性强、副作用小及作用靶点专一的特点，并能提高传统化疗药物对肿瘤细胞的敏感性。课题组前期发现：6449 Da多肽是胃腺癌患者血清中特异性非炎症性生物标志物。本项目承前启后，通过一系列的体内和体外实验，深入探讨并解析Notch信号通路介导6449Da活性肽功能片段WSGC肽最短功能片段促进胃腺癌细胞凋亡和抑制增殖，进而抑制肿瘤发生及恶性进展的分子机制，结果发现：WSGC肽的完整性存在才有抗肿瘤的生物功能，任何一个氨基酸的缺失均会降低或失活其生物活性；WSGC肽对胃腺癌细胞的毒性作用要比对正常胃粘膜上皮细胞作用强，对胃腺癌细胞细胞毒性作用有相对特异性；WSGC肽诱导胃腺癌细胞分裂 S期的阻滞，促进肿瘤细胞凋亡，降低或抑制细胞迁移及跨膜侵袭；WSGC肽通过notch信号通路发挥生物功能，一方面在胃腺癌细胞膜表面与Jagged-1配体竞争结合Notch-1受体，另一方面通过激活泛素化酶促进Notch-1/ Jagged-1蛋白降解，进而发挥抗肿瘤的生物活性。本课题下一步将利用同位素标记进行多肽药物组织分布和物料平衡的药代分析、毒理及临床前安全性评价，积极筹备新药临床试验审批申请，为催生一种新型抗胃腺癌生物活性肽药物的问世及促进胃腺癌的防治工作夯实理论基础。