赤芝中抗肿瘤侵袭转移芳香杂萜的结构、活性与作用机制研究

Tumor invasion and metastasis is one of the main challenges for the treatment of cancer. At present, the drugs used for chemotherapy of tumor invasion and metastasis are still limited, which are also far from meeting the clinical needs for cure rates and survival outcomes. Therefore, it’s an urgent task to develop chemicals for the treatment of tumor invasion and metastasis. Traditional Chinese medicine (TCM) has a long history during the treatment of disease and proved to be effective. Thus, it could be a precious resource of finding the new drug lead compounds (NDLCs) from TCM. During the past decades, it has been controversial about the anti-tumor effect of Ganoderma lucidum. Our previous study shows the extracts of Ganoderma lucidum and some aromatic meroterpenoids (AMs) can significantly inhibit the metastasis of Kyse-30 and HCT-116 cell lines, suggesting that the AMs with novel structures from G. lucidum maybe have the potential to develop into the NDLCs to treat tumor invasion and metastasis, aparting from triterpenes from G. lucidum. Therefore, we intend to further study the separation of novel chemical structures of AMs from G. lucidum guided by Chromatography and Mass Spectrometry, and then systematically evaluate their bioactivities against tumor invasion and metastasis by means of transwell and western bolt etc., and further explore their mechanisms on anti-tumor invasion and metastasis by making use of molecular probe etc., hoping to find the high bioactive NDLCs against tumor invasion and metastasis, and provide the scientific evidence for the anti-cancer claims of G. lucidum and its products.

肿瘤的侵袭转移是癌症治疗面临的主要挑战之一，目前可供临床应用的化学药物还很少，继续开发针对性治疗肿瘤侵袭转移的药物仍是一项迫切任务。中药是人类长期医疗实践的产物，以其为资源来寻找新的药物先导化合物是一种获得新药的重要途径。“中华仙草”赤芝是否具有抗癌或辅助抗癌功效长期以来备受争议。前期，我们发现赤芝的提取物组份及其部分芳香杂萜（AMs）成分具有明显的抑制食管癌细胞Kyse-30和直肠癌细胞HCT-116迁移的能力，提示具备独特结构新颖性的AMs可能是赤芝中区别于三萜的一类具有开发为新抗肿瘤侵袭转移药物潜力的结构家族。前期研究表明，AMs在灵芝属真菌中大量存在且结构多样。本项目旨在采用定向分离的策略开展赤芝中AMs的再研究，利用Tanswell等方法评价其抗肿瘤侵袭转移的活性，并借助分子探针等手段探讨其作用机制，期望为抗肿瘤侵袭转移药物的开发奠定基础，也为赤芝及其产品的抗癌宣称提供科学依据。

灵芝，又被称为“中华仙草”，是国内外著名的真菌类中药。纵观灵芝的知名度和研究热潮，足以体现其在大众心中的地位。本项目的研究内容主要涉及赤芝杂萜结构的定向分离鉴定、化合物的抗肿瘤侵袭转移活性测试、活性化合物的开展结构的定向修饰、构效关系和生物合成途径以及作用机制的研究、围绕抗肿瘤侵袭转移活性的作用机制研究。项目总体执行情况较好，完成了任务书要求的内容。具体而言，我们借住前期总结的LC-UV/DAD-MS在内的灵芝杂萜定向获取的策略，从大姚赤芝、保山赤芝和永胜赤芝中共计分离化合物171个化合物，新化合物74个，围绕5种人肿瘤细胞 Kyse 30，A549，BGC-823，MDA-MB-231和HepG2细胞活性研究，发现6个杂萜具有抑制肿瘤细胞迁移的活性。根据项目前期研究基础，在细胞和动物水平上，灵芝天然产物LZ-22均具有抗三阴性乳腺癌增殖和迁移的活性，我们选用此化合物作为探针设计和合成的对象。前期已对该化合物完成了全合成，解决了进一步研究量的问题。进行化学生物学探针合成，采用pulldown和DARTS的方式研究其靶标，目前，已确定PABPC1蛋白和ITGB1蛋白为其作用靶点，进一步共晶研究中。本项目研究所产生的结果将对《中国药典》收载赤芝所含灵芝杂萜类化合物的认识有了进一步的突破，同时抗肿瘤活性及机制的研究将进一步阐明灵芝抗肿瘤药效物质基础不仅仅只是三萜和多糖发挥作用，灵芝杂萜也是需要被重点关注的一大类化合物，值得进一步深入挖掘研究。