左金丸通过PI3k/Akt/NF-κB信号通路抑制ABCB1介导的大肠癌耐药的机制研究

Multidrug resistance (MDR) is the main reason of ineffectiveness of colon cancer (CC) chemotherapy. Our preliminary data showed that activated Akt (pAkt) through upstream PI3K signaling induced nuclear translocation of NF-κB, which consequently promoted the transcription/translation of MDR gene ABCB1, resulting in drug resistance of CC; TCM Zuo Jin Wan (ZJW) down-regulated the expression levels of ABCB1, increased chemo-sensitivity of CC, and inhibited phosphorylation of Akt. We hypothesize the repression of the PI3K/Akt NF-κB/ABCB1 signaling axis may account for ZJW's chemo-sensitivity restoring effect on CC cells. We therefore propose to generate a ABCB1 luciferase construct, a 3D culture drug sensitivity assay, use techniques such as real-time PCR, western blotting, and utilize primary CC samples, human MDR CC cell lines, animal models to study how ZJW represses this signaling cascade to overcome the chemo-resistance in CC cells. This study of ours will not only elucidate the therapeutical mechanism of ZJW, but also define novel treatable targets for TCM in CC.

多药耐药（MDR）是导致大肠癌化疗疗效的主要原因之一。我们前期研究发现PI3k/Akt信号通路激活，磷酸化的Akt能够激活NF-κB进入细胞核参与多药耐药基因ABCB1的转录与翻译，引起大肠癌的MDR；中药左金丸下调ABCB1基因转录与翻译，增加大肠癌化疗敏感性，抑制Akt的磷酸化。因此我们推测抑制PI3k/Akt/NF-κB信号通路下调ABCB1可能是左金丸逆转多药耐药的重要机制。.因此，本研究构建ABCB1启动子序列报告基因，采用三维培养药敏实验，Real-time PCR, Western blot等技术，以人大肠癌标本，人结肠癌耐药细胞、动物模型为研究对象，探讨左金丸对PI3k/Akt/NF-κB/ABCB1信号传递的调控机制及其与大肠癌多药耐药的生物关系。这对于揭示左金丸抑制大肠癌多药耐药的机制，明确中药逆转大肠癌多药耐药的作用靶点具有重要的科学意义。

多药耐药（MDR）是导致大肠癌化疗失败的主要原因之一。我们前期研究发现PI3k/Akt信号通路激活，磷酸化的Akt能够激活NF-κB进入细胞核参与多药耐药基因ABCB1的转录与翻译，引起大肠癌的MDR；中药左金丸下调ABCB1基因转录与翻译，增加大肠癌化疗敏感性，抑制Akt的磷酸化。因此我们推测抑制PI3k/Akt/NF-κB信号通路下调ABCB1可能是左金丸逆转多药耐药的重要机制。.因此，本研究构建ABCB1荧光素酶报告基因，采用三维培养药敏实验，Real-time PCR, Western blot等技术，以人大肠癌标本，人结肠癌耐药细胞、动物模型为研究对象，探讨左金丸对PI3k/Akt/NF-κB/ABCB1信号传递的调控机制及其与大肠癌多药耐药的生物关系。这对于揭示左金丸抑制大肠癌多药耐药的机制，明确中药逆转大肠癌多药耐药的作用靶点具有重要的科学意义。