mTOR介导的细胞自噬在粉防己碱抗前列腺癌侵袭迁移的作用机制研究

Accumulating evidence indicates that tendency to invade and transfer is associated with malignant progression of prostate cancer, which is one of the obstacles for prostate cancer treatment. Tetrandrine, a traditional Chinese herbal, exerts antitumor effect in various cancer，while the mechanism of tetrandrine on anti-invasive effect has not been elucidated. Our previous study demonstrated that tetrandrine significantly suppressed migration and invasion and downregulated the levels of p-Akt, p-mTOR and MMP-9 in prostate cancer cells. What’s more, cell autophagy is also found in our pre-experiments, and mTOR is the vital negative regulator of autophagy, suggesting that autophagy mediated by mTOR has a close correlation with cancer migration and invasion. In addition, it was reported that autophagy could promote the releasing of inflammatory chemokines in the tumor microenviroment. Based on all above, we strongly believe that autophagy initiated by tetrandrine can regulate chemokines secreting to inhibit prostate cancer cells migration and invasiveness. In our following study, we will focus on the anticancer efficacy and mechanisms of tetrandrine on prostate cancer migration and invasion, and cell autophagy via in-vitro assays and metastatic model in nude mice; subsequently, we will demonstrate the potential mechanisms of autophagy and the downstream chemokines participating in the inhibitory of migration and invasion with the measure of autophagy regulators, gene chip and siRNA transfection, to investigate the possibility of cell autophagy as a potential therapeutic target for repressing prostate cancer migration and invasiveness.

大量证据表明前列腺癌进程中易发侵袭转移，这是前列腺癌治疗一大难题。粉防己碱这一中草药在多种肿瘤表现出抗癌作用，但其抗肿瘤侵袭机制尚不清楚。我们前期研究发现，粉防己碱显著抑制前列腺癌细胞的侵袭迁移，并下调侵袭相关蛋白（p-Akt、p-mTOR和MMP-9）表达，且粉防己碱处理后前列腺癌细胞中有自噬现象，而mTOR是自噬关键性负向调控子，可知mTOR介导的细胞自噬与肿瘤侵袭迁移有紧密联系。而细胞自噬在肿瘤微环境中能促进炎性趋化因子释放，因此我们推测细胞自噬可能诱导趋化因子分泌，参与粉防己碱抗肿瘤侵袭迁移过程。本研究拟用体外实验和裸鼠肺转移模型，通过Transwell侵袭迁移等实验，探究粉防己碱抗前列腺癌侵袭迁移机制和调控细胞自噬机理，利用自噬调节剂、基因芯片、siRNA转染等探究细胞自噬及其诱导分泌的趋化因子抗肿瘤侵袭迁移的作用及相关机制，以及细胞自噬作为治疗靶点用于抗肿瘤侵袭迁移的可能性。

肿瘤易发侵袭转移是肿瘤治疗的一大难题。粉防己碱这一中草药在多种肿瘤表现出抗癌作用，但其抗肿瘤侵袭机制尚不清楚。我们前期研究发现，粉防己碱显著抑制前列腺癌细胞的侵袭迁移，而细胞自噬与肿瘤侵袭迁移、凋亡等生物学行为有紧密联系。因此我们推测细胞自噬可能了参与粉防己碱抗肿瘤侵袭迁移过程。本研究通过体内外实验探究粉防己碱抗多种肿瘤的侵袭迁移机制和调控细胞自噬机理，以及细胞自噬作为治疗靶点用于抗肿瘤侵袭迁移的可能性。我们通过MTT实验、细胞划痕实验、Transwell实验、实时定量PCR、western blot、GFP-RFP-LC3实验、透射电镜实验、LC3 turnover、流式细胞仪技术、平板克隆实验、裸鼠移植瘤模型等实验研究发现：1) 粉防己碱能通过抑制前列腺癌细胞自噬流进而抑制上皮间质转化过程；2) 粉防己碱通过激活 LKB1/AMPK 介导的细胞自噬诱导膀胱癌细胞的凋亡过程；3) 粉防己碱通过激活内质网应激诱导喉癌细胞的凋亡；4) 粉防己碱通过拮抗 JAK2/STAT3 信号通路抑制甲状腺癌的上皮间质转化过程。