基于PI3K/Akt/mTOR通路抑制的鹅不食草中倍半萜内酯类抗鼻咽癌化合物的发现及作用机制研究

Nasopharyngeal carcinoma (NPC) is one of the most common malignancies with high incidence rate in southern China. Currently, concurrent radiotherapy and chemotherapy is still the first line treatment for NPC and there is no specific drug developed for NPC so far. Thus, discovery of specific effective anticancer agents targeting NPC is much more important. PI3K/AKT/mTOR signaling pathway is an important target of anticancer drugs and plays crucial role in the tumorigenesis and development of NPC. In our anticancer agent screening on herbal medicine, Centipeda minima, one of the commonly used traditional Chinese medicines for the treatment of rhinitis, has shown a significant anti-tumor effect against NPC, as well as eight sesquiterpene lactones were isolated from the herb. Further Pharmacological and Molecular biological investigation indicated that ethanolic extracts and a new isolated sesquiterpene lactone showed significant growth inhibition and apoptosis induction against NPC cell lines CNE-1 and CNE-2 in vitro and in vivo. They can down-regulated the expression of p-PI3k, p-Akt and p-mTOR as well. We hypothesis that the anticancer activity against NPC of sesquiterpene lactones may associate with their inhibition on PI3K/AKT/mTOR signaling pathway. Therefore, in the present proposal, we continue to isolate sesquiterpene lactone compounds from Centipeda minima, make structure modification on the isolated compounds as well as structure-activity relationship study. We will also investigate the inhibition mechanism of these compounds on PI3K/AKT/mTOR signaling pathway and key protein targets. Our research will elucidate the mechanism of anti-NPC activity of sesquiterpene lactones and establish a solid theoretical foundation for anti-NPC drugs discovery targeting PI3K-AKT-mTOR signaling pathway as well as provide potent leading compounds.

鼻咽癌是高发于我国华南地区的恶性肿瘤之一，尚无特异靶向药物，放化疗依然是主流疗法，特异性靶向药物的研发具有重要意义。PI3K/AKT/mTOR信号通路是抗肿瘤药物的重要靶标之一，在鼻咽癌的发生和发展中起关键性作用。我们前期研究发现常用于治疗鼻炎的中药鹅不食草具有显著的抗鼻咽癌活性，并从中分离到8个倍半萜内酯化合物；体内外活性研究发现，其乙醇提取物和其中一个新的倍半萜内酯化合物都能显著抑制鼻咽癌细胞CNE-1，CNE-2生长并诱导其凋亡，并抑制PI3K,AKT和mTOR蛋白磷酸化；提示该类化合物的抗癌活性可能与抑制该通路有关。本项目拟在前期基础上，继续系统分离倍半萜内酯成分，并进行结构修饰；评价该类成分抗鼻咽癌活性及构效关系；探讨其抑制PI3K/AKT/mTOR通路和关键靶点的作用机制；系统阐明鹅不食草倍半萜内酯抗鼻咽癌活性及作用的分子机制，为抗鼻咽癌靶向药物的研发提供研究基础和先导化合物。

鼻咽癌是高发于我国华南地区的恶性肿瘤之一，尚无特异靶向药物，放化疗依然是主流疗法，特异性靶向药物的研发具有重要意义。PI3K/AKT/mTOR信号通路是抗肿瘤药物的重要靶标之一，在鼻咽癌的发生和发展中起关键性作用。因此，从天然产物中发现PI3K/Akt/mTOR抑制剂，对于抗鼻咽癌药物研发具有必要性和可能性。本项目在前期基础上，继续对中药鹅不食草中倍半萜内酯成分进行系统分离和结构修饰；评价该类成分抗鼻咽癌活性及构效关系；探讨其抑制PI3K/AKT/mTOR通路和关键靶点的作用机制；系统阐明鹅不食草倍半萜内酯抗鼻咽癌活性及作用的分子机制，为抗鼻咽癌靶向药物的研发提供研究基础和先导化合物。研究结果：1）分离鉴定了17倍半萜内酯类化合物，其中1个为新化合物，7个为首次从该植物中发现；2）用MTT法对化合物进行体外活性筛选，发现短叶老鹳草素Brevilin A （BA)，山金车内酯D Arnicolide D（AD）和毛栲利素Lasiokaurin （LAS）具有显著的抗鼻咽癌（NPC）作用；3）BA，AD和LAS均能显著抑制荷瘤裸鼠中肿瘤的生长；4）BA，AD和LAS均可诱导NPC细胞凋亡，阻滞细胞周期于G2/M期，抑制NPC细胞迁移；5）BA，AD和LAS均能抑制PI3K，AKT，mTOR的磷酸化，从而抑制PI3K/AKT/mTOR通路的激化；6）BA，AD和LAS也能抑制Stat3，NF-KB等通路；7）BA，AD尚能具有抑制黑色素瘤及三阴乳腺癌的作用，其作用机制与NPC相似；8）以BA为母化合物，进行结构修饰，获得33个衍生物，利用MTT法对其体外抗肿瘤活性进行了评价，并分析其构效关系，并获得了2个活性高于BA的先导化合物。.本项目具有较强的前瞻性，为抗NPC创新药物研发提供了研究基础及2个先导化合物，具有重要的经济和社会价值。发表论文14篇，培养硕士研究生3名。