蟾酥是临床常用抗肿瘤药物，除所含小分子甾烯外，来自腺体分泌的多肽在其中发挥重要作用。由于毒素多肽具水-脂两亲结构和特定氨基酸序列，能通过电荷吸引及受体介导方式与肿瘤细胞直接结合。这种亲和性使蟾酥多肽诱发抗肿瘤/免疫反应效应，构成蟾酥整体取效的一个独特方面。本项目采用药理评价和生化分离技术，对蟾酥抗肿瘤多肽进行鉴定与序列解析及构-效关系研究。工作路径：① 在整体/细胞水平，以抗肿瘤细胞增殖和促淋巴因子释放为指标，评价蟾酥总肽的效应，进一步筛选有效部位。② 建立亲和筛选模型，采用液相-质谱及转录组从头测序技术鉴定有效部位与肿瘤细胞/蛋白直接结合的蟾酥多肽分子。③ 开展目标导向的蟾酥多肽分离/纯化，合成制备及活性验证研究，总结分析序列结构与亲和性及抗肿瘤活性间关系。揭示蟾酥抗肿瘤的大分子物质基础，为药材/制剂质量控制、产品精制和新药开发提供科学依据。

Toad venom (chansu) is a common Chinese medicine in the treatment of tumor diseases. The therapeutic effect of toad venom is due to its major active ingredients, not only the bufadienolides but also peptides, secreted by parotid glands. Venom peptides have amphiphilic groups and specific amino acid sequences, which could interact with cancer cells in the modes of electrostatic attraction and receptor-ligand binding, to cause the modification on the surface of cancer cells via peptide self-aggregation. This bio-affinity makes the venom peptides exert anti-tumor and immunostimulatory actions. In this project, the anti-tumor peptides in toad venom (TVP) and their structure-activity relationship would be investigated. Firstly, effects of TVP on the tumor cell proliferation and level of Th1/Th2 cytokines would be examined in vivo and vitro models. Then, TVP would be divided into fractions for the next activity screening. Secondly, the active peptides would be determined by the cell/protein affinity purification-mass spectrometry, and be sequenced using De-novo transcriptomics based database search. Thirdly, the pure anti-tumor peptides would be obtained via bioassay guided isolation/purification, mass identification and chemical synthesis. Finally, the structure-activity relationship of TVP would be identified to reveal the anti-tumor material basis of toad venom. This study would benefit the quality control, refining and new drug development of toad venom.