基于Nrf2/SLC7A11/GPX4信号通路探讨附芍地芩方抗结直肠癌作用机制

Exploring the Mechanism of Anti-Colorectal Cancer Action of Fushao Diqin Decoction Based on the Nrf2/SLC7A11/GPX4 Signaling Pathway

目的探讨附芍地芩方治疗结直肠癌的作用机制。方法体外细胞实验用附芍地芩方处理结直肠癌CT-26细胞,检测细胞增殖、迁移能力。流式细胞术检测结直肠癌CT-26细胞的活性氧(ROS)水平,并检测其铁离子(Fe^(2+))、丙二醛(MDA)水平及超氧化物歧化酶(SOD)活性。PCR Array与Western blot方法分析验证铁死亡差异基因表达情况。体内动物实验将Balb/c小鼠随机分为空白对照组、模型组、奥沙利铂组(1.5 mg·kg^(-1)·d^(-1))、附芍地芩方低剂量组(4.49 g·kg^(-1)·d^(-1))、附芍地芩方中剂量组(8.97 g·kg^(-1)·d^(-1))、附芍地芩方高剂量组(17.94 g·kg^(-1)·d^(-1)),检测附芍地芩方对小鼠肿瘤组织Fe^(2+)、ROS、MDA水平,SOD活性及Nrf2、Keap1、SLC7A11、GPX4表达水平的影响。结果体外细胞实验显示,与空白对照组相比,附芍地芩方通过剂量依赖的方式显著抑制了结直肠癌CT-26细胞的增殖与迁移。附芍地芩方可以提高结直肠癌CT-26细胞中的Fe^(2+)(P<0.05)与ROS水平(P<0.01);提高结直肠癌CT-26细胞内MDA水平(P<0.01),并显著降低SOD活性(P<0.01)。铁死亡PCR Array分析发现,与空白对照组比较,附芍地芩方干预后,基因GPX4、SLC7A11表达显著下调,GSTA1、HMOX1、Ca9、Chac1、Keap1、Sqstm1、NOX1、FTH1、Tfr1、SAT2、Pparg、Hamp表达显著上调。Western blot实验检测发现,附芍地芩方干预后,结直肠癌CT-26细胞Keap1蛋白表达上调(P<0.01),Nrf2、SLC7A11、GPX4蛋白表达下调(P<0.01)。体内动物实验结果显示,附芍地芩方显著抑制小鼠皮下移植瘤的生长(P<0.05),肿瘤组织坏死程度增加,Fe^(2+)、ROS以及MDA水平增加(P<0.05,P<0.01),SOD活性下降(P<0.01),且肿瘤组织中Keap1蛋白表达上调(P<0.01),Nrf2、SLC7A11、GPX4蛋白表达下调(P<0.01)。结论附芍地芩方具有抗结直肠癌作用,并可能通过抑制Nrf2/SLC7A11/GPX4信号通路促进结直肠癌细胞铁死亡以发挥抗结直肠癌作用。

OBJECTIVE To explore the mechanism of action of Fushao Diqin Decoction in the treatment of colorectal cancer.METHODS In vitro cell experiments were conducted using Fushao Diqin Decoction to treat colorectal cancer CT-26 cells,and the cell proliferation and migration abilities were detected.Flow cytometry was used to detect the levels of reactive oxygen species(ROS)in colorectal cancer CT-26 cells,as well as the levels of iron ions(Fe^(2+)),malondialdehyde(MDA),and the activity of superoxide dismutase(SOD).PCR Array and Western blot methods were used to analyze and verify the differential gene expression of ferroptosis.Balb/c mice were randomly divided into a blank control group,a model group,an oxaliplatin group(1.5 mg·kg^(-1)·d^(-1)),a low-dose group of Fushao Diqin Decoction(4.49 g·kg^(-1)·d^(-1)),a medium dose group of Fushao Diqin Decoction(8.97 g·kg^(-1)·d^(-1)),and a high-dose group of Fushao Diqin Decoction(17.94 g·kg^(-1)·d^(-1))for in vivo animal experiments.The effects of Fushao Diqin Decoction on Fe^(2+),ROS,MDA levels,SOD activity,and Nrf2,Keap1,SLC7A11 and GPX4 expression levels in mouse tumor tissues were tested.RESULTS In vitro cell experiments showed that compared with the blank control group,Fushao Diqin Decoction significantly inhibited the proliferation and migration of colorectal cancer CT-26 cells in a dose-dependent manner.Fushao Diqin Decoction could increase the Fe^(2+)content(P<0.05)and ROS level(P<0.01)in colorectal cancer CT-26 cells,increase the MDA level in CT-26 cells of colorectal cancer(P<0.01)and significantly reduce SOD activity(P<0.01).Iron death PCR array analysis found that compared with the blank control group,after intervention with Fushao Diqin Decoction,the expression of genes GPX4 and SLC7A11 was significantly downregulated,while the expression of GSTA1,HMOX1,Ca9,Chac1,Keap1,Sqstm1,NOX1,FTH1,Tfr1,SAT2,Pparg,and Hamp was significantly upregulated.Western blot analysis revealed that after intervention with Fushao Diqin Decoction,the expression of Keap1 protein was upregulated(P<0.01),while the expression of Nrf2,SLC7A11,and GPX4 proteins was downregulated(P<0.01)in colorectal cancer CT-26 cells.The results of in vivo animal experiments showed that Fushao Diqin Decoction significantly inhibited the growth of subcutaneous transplanted tumors in mice(P<0.05),increased the degree of tumor tissue necrosis,and levels of Fe^(2+),ROS,and MDA(P<0.05,P<0.01),decreased SOD activity(P<0.01)and upregulated Keap1 protein expression(P<0.01),while downregulated Nrf2,SLC7A11,and GPX4 protein expression(P<0.01).CONCLUSION Fushao Diqin Decoction has an anti-colorectal cancer effect and may promote ferroptosis in colorectal cancer cells by inhibiting the Nrf2/SLC7A11/GPX4 signaling pathway to exert its anti-colorectal cancer effect.