白花丹醌通过CXCL8/PI3K/AKT糖酵解通路抑制结肠癌细胞增殖、促进凋亡

目的:观察白花丹醌对结肠癌细胞Caco-2增殖、凋亡的影响，探究其潜在的作用机制。方法:运用CCK8法、流式细胞术检测不同浓度白花丹醌（4、8、12 μmol/L）处理的Caco-2细胞的增殖抑制率、凋亡率。不做任何处理的Caco-2细胞设为Control；脂质体法将si-NC组（转染si-NC）、si-CXCL8组（转染si-CXCL8）转染至Caco-2细胞；8 μmol/L的白花丹醌与0.5%DMSO处理的Caco-2细胞设为8 μmol/L+DMSO组；8 μmol/L的白花丹醌分别与z-VAD-FMK、740Y-P处理的Caco-2细胞设为8 μmol/L+z-VAD-FMK组、8 μmol/L+740Y-P组。RT-qPCR、Western blot实验检测细胞中CXCL8的mRNA、蛋白表达，CXCL8、M2-型丙酮酸激酶（M2 pyruvate kinase, PKM2）、L-乳酸脱氢酶A（lactate dehydrogenase A,LDHA）、人α-烯醇化酶(apha-enolase,ENO1)、葡萄糖磷酸异构酶（glucose phosphate isomerase,GPI）、磷酸化磷脂酰肌醇3激酶（phosphorylated phosphatidylinositol 3 kinase,p-PI3K）、磷酸化蛋白激酶B（phosphorylated protein kinase B,p-AKT）的蛋白表达。结果:与Control组相比，白花丹醌（4、8、12 μmol/L）呈浓度依赖性促进Caco-2细胞增殖抑制率、凋亡率升高，抑制CXCL8的mRNA和蛋白表达。与8 μmol/L+DMSO组相比，8 μmol/L+z-VAD-FMK组细胞的增殖抑制率、凋亡率明显降低，CXCL8的mRNA和蛋白表达明显升高（P＜0.05）。白花丹醌（4、8、12 μmol/L）呈浓度依赖性抑制PKM2、LDHA、p-PI3K、p-AKT的蛋白表达。si-CXCL8组PKM2、LDHA、p-PI3K、p-AKT的蛋白表达明显低于si-NC组。740Y-P明显减弱白花丹醌对Caco-2细胞增殖抑制率和凋亡率的促进作用。结论:白花丹醌抑制结肠癌细胞增殖，促进凋亡，其潜在的作用机制与CXCL8/PI3K/AKT糖酵解通路有关。

Plumbagin inhibits proliferation and promotes apoptosis of colon cancer cells through CXCL8/PI3K/AKT glycolysis pathway

Objective:To observe the effect of plumbagin on cell proliferation and apoptosis of Caco-2,and explore its potential mechanism.Methods:Cell count（CCK8) and flow cytometry were used to measure the proliferation inhibition rate and apoptosis rate of Caco-2 cells treated with plumbagin（4,8,12 μmol/L).Caco-2 cells without any treatment were set as the Control group.si-NC group（transfected si-NC) and si-C-X-C motif chemokine ligand 8（CXCL8) group（transfected si-CXCL8) were transfected into Caco-2 cells by liposome method.Caco-2 cells treated with 8 μmol/L plumbagin and 0.5% DMSO were set as 8 μmol/L+DMSO group.Caco-2 cells treated with 8 μmol/L plumbagin and z-VAD-FMK or 740Y-P were set as 8 μmol/L+z-VAD-FMK group,8 μmol/L+740Y-P group,respectivly.The mRNA and protein expression of CXCL8 were measred by real-time fluorescence quantitative polymerase chain reaction（RT-qPCR) and Western blot（WB).CXCL8,M2 pyruvate kinase（PKM2),glyceraldehyde-3-phosphate dehydrogenase（LDHA),human α-enolase（ENO1),glucose phosphate isomerase（GPI),phosphorylated phosphatidylinositol 3 kinase（p-PI3K) and phosphorylated protein kinase B（p-Akt) were measred by Western blot.Results:Compared with the Control group,plumbagin（4,8,12 μmol/L) promoted the proliferation inhibition rate and apoptosis rate of Caco-2 cells and inhibited the mRNA and protein expression of CXCL8 in a concentration dependent manner.Compared with 8 μmol/L+DMSO group,the proliferation inhibition rate and apoptosis rate significantly decreased,and the mRNA and protein expression of CXCL8 significantly increased in 8 μmol/L+z-VAD-FMK group（P<0.05).Plumbagin（4,8,12 μmol/L) inhibited the protein expression of PKM2,LDHA,p-PI3K and p-AKT in a concentration dependent manner.The protein expressions of PKM2,LDHA,p-PI3K and p-AKT in si-CXCL8 group were significantly lower than those in si-NC group.740Y-P significantly weakened the promoting effect of plumbagin on the proliferation inhibition rate and apoptosis rate of Caco-2 cells.Conclusion:Plumbagin could inhibit the proliferation and promote apoptosis of colon cancer cells,and its potential mechanism may be related to CXCL8/PI3K/AKT glycolysis pathway.