抑癌方对ROS/HIF-1α途径调控血管拟态促进大肠癌侵袭转移的干预

Invasion and metastasis of colorectal cancer is the leading cause of death related. Vascular Mimicry (VM) play a key role in the course and ROS/HIF-1α pathway is its main regulatory mechanisms. Currently there is neither mature and effective treatment for tumour VM, nor any report about intervention of Chinese herbs on VM formation of colorectal cancer. Yiaifang can effectively treat invasion and metastasis of colorectal cancer and our preliminary studies indicate the treatment is closely related to the fact that it can significantly inhibit VM formation, but the specific mechanism is still unknown. We also found that the herb compound can reduce the level of HIF-1α、VEGF and MMP2 of ROS/HIF-1α pathway in mouse xenograft and let down the activity of MMP2 in vitro. Therefore, we propose that its intervention on the course of ROS/HIF-1αpathway regulating VM formation is the mechanism of its anti-invasion and metastasis of colorectal cancer. On the base of validating the fact that ROS/HIF-1α pathways can regulate the formation of VM and then promote the invasion and metastasis of colorectal cancer,the project intends to focus on which molecules of ROS/HIF-1α pathways can mediate its effection on the VM formation and invasion and metastasis of colorectal cancer. The expected results will be able to not only clarify its mechanism, but also provide theoretical support and experimental evidence for Chinese herb treating colorectal cancer invasion and metastasis via inhibiting VM formation.

大肠癌侵袭转移，是其相关死亡的主要原因。血管拟态（VM）在其中扮演着关键角色，ROS/HIF-1α途径是VM的主要调控机制。目前尚无有效的肿瘤VM治疗方法，也未见中药干预大肠癌VM形成的文献报道。 抑癌方在大肠癌侵袭转移上有确切疗效，我们前期研究表明，这与抑制VM形成有关，但具体机制不明。我们还发现，该方能下调小鼠移植瘤内ROS/HIF-1α途径上的HIF-1α和VEGF水平、减少MMP2表达，体外研究能降低MMP2活性。因此，提出干预ROS/HIF-1α途径调控VM形成是该方抗大肠癌侵袭转移的机制。 本项目拟研究：1）验证ROS/HIF-1α途径调控VM形成促进大肠癌侵袭转移的作用；2）通过体内外实验，重点研究该途径上是哪些分子介导抑癌方发挥抑制大肠癌VM形成和侵袭转移的作用。预期结果不仅有助于明确其作用机制，也为中医药通过抑制VM治疗大肠癌侵袭转移提供理论支持和实验依据。

课题组前期研究发现抑癌方在大肠癌侵袭转移上有确切疗效，该方能明显抑制大肠癌细胞的侵袭转移，且与抑制 VM 形成有关，但具体机制不明。我们发现该方能下调小鼠移植瘤内ROS/HIF-1α途径上的HIF-1α和VEGF水平、减少 MMP2 表达，体外研究能降低 MMP2 活性。因此，我们提出干预 ROS/HIF-1α途径调控VM形成是该方抗大肠癌侵袭转移的关键机制。课题组最新研究进一步证实该机制。体外研究发现，缺氧条件下血管拟态形成显著增多，细胞迁移能力显著增强，NAC能够显著抑制细胞血管拟态形成和迁移能力；同时进一步探讨 ROS/HIF-1α通路发现，缺氧微环境下，ROS水平显著增多，NAC能显著抑制 ROS，且缺氧能上调HIF-1α和MMP2的表达，NAC能显著下调HIF-1α和MMP2的表达；我们发现抑癌方能抑制大肠癌细胞活性，呈剂量依赖性，且该方抑制 ROS，同时抑制细胞血管拟态形成和迁移能力，抑癌方能抑制 HIF-1α、MMP2 蛋白表达；研究进一步发现该方能作用于抑癌基因VHL，使其蛋白表达曾强，进而促进HIF-1α降解，抑制MMP表达。体内实验建立Balb/c 裸鼠转移瘤模型证实，抑癌方能够有效抑制大肠癌转移瘤。