健脾解毒方通过NF-κB调节Nrf2/MRP2信号通路逆转大肠癌多药耐药的作用机制

Resistance to chemotherapy limits the effectiveness of colorectal cancer. MRP2 transporters play an important role in multidrug resistant colorectal cancer. We previously showed that the activation of Nrf2/MRP2 signaling pathway can mediate the occurrence of multidrug resistance in colorectal cancer. Meanwhile, Jianpi Jiedu Recipe could reverse drug resistance of human colorectal cancer, down regulate the expressions of NF-κB and MRP2, and prevent nuclear translocation of Nrf2. However, the regulatory mechanism of Nrf2/MRP2 signaling pathway is unclear. Recent study showed that NF-κB could activate the transcription of Nrf2 gene, and the increase of protein expression and nuclear translocation of Nrf2 are one of the important factors of MRP2 gene transcription. Therefore, we hypothesized that NF-κB may be the reason of Nrf2/MRP2 signaling pathway mediated drug resistance in colorectal cancer and Jianpi Jiedu Recipe may reverse drug resistance via NF-κB/Nrf2/MRP2 signaling pathway in colorectal cancer. .In this study, we explore the effect of Jianpi Jiedu Recipe in NF-κB/Nrf2/MRP2 signaling mediated drug resistance in colorectal cancer cells through immunofluorescence staining, flow cytometry and other experimental technologies. It will be helpful to elucidate molecular mechanism and find the new way in the prevention and treatment of drug-resistant colorectal cancer.

多药耐药是导致大肠癌化疗失败的主要原因之一，MRP2蛋白在多药耐药中发挥重要作用。课题组前期发现，Nrf2能够调控MRP2介导的大肠癌多药耐药，健脾解毒方能够逆转大肠癌多药耐药，并能下调NF-κB、Nrf2及MRP2的表达，但Nrf2/MRP2是通过什么途径调控的尚不清楚。最新研究表明NF-κB能够启动Nrf2转录，而Nrf2表达上调及核转位是引起MRP2基因转录的重要因素之一。因此，我们提出假说NF-κB可能是调控Nrf2/MRP2信号通路介导的大肠癌耐药的重要途径之一；健脾解毒方可能通过NF-κB调节Nrf2/MRP2信号通路逆转大肠癌耐药。. 本研究通过荧光免疫染色、流式细胞术、小动物活体成像等方法，探讨健脾解毒方对NF-κB/Nrf2/MRP2信号传递介导的大肠癌耐药的调控机制。这对于揭示大肠癌耐药的机理，明确中药防治大肠癌耐药的新途径，具有重要的临床意义。

结直肠癌是世界第三大癌症。手术切除是大肠癌治疗的首选方法。对于晚期及术后复发者，化疗是主要的治疗手段。但临床由于肿瘤细胞出现化疗耐药导致化疗失败。因此，怎样提高大肠癌对化疗的敏感性，是目前大肠癌治疗亟待解决的关键问题。.课题组前期研究发现Nrf2能够调控MRP2介导的大肠癌多药耐药，健脾解毒方能够逆转大肠癌多药耐药，并能下调NF-κB、Nrf2及MRP2的表达，但Nrf2/MRP2是通过什么途径调控的尚不清楚。.因此，本研究以人肠癌耐药细胞和动物模型为研究对象，构建NF-κB慢病毒载体质粒，采用Nrf基因干扰、荧光免疫染色、流式细胞术、CHIP等方法，发现MRP2的异常表达和NF-κB/Nrf2信号通路的激活密切相关。体内外实验也提示，肠癌细胞中NF-κB能够激活Nrf2启动子活性并促进Nrf的表达，从而进入细胞核内，启动MRP2的转录，诱导大肠癌细胞的多药耐药。.本研究通过建立NF-κB过表达的肠癌细胞及Nrf2低表达的肠癌细胞，采用Real-time PCR、Western blot、细胞免疫荧光、克隆形成等实验技术，观察健脾解毒方对大肠癌细胞中MRP2表达的调节作用及对大肠癌耐药的影响。我们发现健脾解毒方能够降低耐药蛋白MRP2的表达，增加细胞对奥沙利铂的敏感性。此外，健脾解毒方能够抑制NF-κB/Nrf2信号通路的激活，从而降低MRP2的表达，逆转耐药。这对于揭示中药逆转耐药的作用机制，为中医药防治大肠癌耐药提供科学依据。.标注该课题的文章8篇，其中SCI收录5篇。培养硕士研究生2名。