Effects Of Bergenin On The Biological Behavior Of Colon Cancer Cells Through PI3K/AKT/mTOR Signaling Pathway And Its Mechanism

Objective:Colorectal cancer is a common malignant tumor of the digestive tract,and its related signaling pathways have always been the focus of the pathogenesis researches.This study was to investigate the effects of PI3K/AKT/mTOR signaling pathway on proliferation,apoptosis and cell cycle of colon cancer cells,and the inhibitory effect and mechanism of bergenin on colorectal cancer through PI3K/AKT/mTOR signaling pathway.The findings would help to find drugs that regulate key factors in the PI3K/AKT/mTOR signaling pathway and may have profound effects on the treatment of colorectal cancer.Methods:Forty-five patients with colorectal cancer were enrolled in the study.Experiments were conducted to detect the expressions of PI3K,AKT and mTOR in cancer tissues,normal tissues and the relationship between PI3K,AKT and mTOR and the clinical features of patients were analyzed.Colon cancer HCT116 cells were treated with different concentrations of bergenin.The expressions of AKT and mTOR were detected by western blot.The cell viability,apoptosis and cycle were analyzed by MTT and flow cytometery.The colon cancer xenografts model was established to observe the effect of bergenin on tumor formation in nude mice.Results:1.The expression of PI3K,AKT and mTOR mRNA in human colorectal cancer tissues were(1.785±0.21),(1.647±0.25)and(1.985±0.19)folds higher than that of the normal tissues,respectively(p<0.01).The expression of PI3K,AKT and mTOR proteins were much higher in cancer tissues than that of the normal tissues(P<0.05).2.The expression of PI3K and mTOR in colorectal cancer tissues were related to the patient's TNM stage,the differentiation degree,tumor volume and lymph node or distal metastasis,the expression of AKT in colorectal cancer tissues was related to the TNM stage,lymph node or distal metastasis.3.The proliferation rate of the 3?M group,10 ?g group and 30 ?M group was significantly lower than that of the control group(p<0.01).The bergenin promoted the apoptosis of colon cancer cells in a dose-dependent manner.The apoptosis rate of 10 ?M group and 30 ?M group was statistically higher than that of the control group(p<0.05,p<0.01).The bergenin induced the G0/G1 phase rest of colon cancer cells in a dose-dependent manner.The proportion of G0/G1 phase cells in the 10 ?M group and 30 ?M group was significantly higher than that of the control group(p<0.01).4.The level of p-H2AX in 10 ?M group and 30 ?M group was higher compared with the control group(p<0.05,p<0.01).5.The ROS levels in 10 ?M group and 30 ?M group were statistically different from those in the control group(p<0.05).The ROS levels in 30 ?M bergenin+5 mM NAC group were significant lower than that in the 30 ?M group(p<0.01),which had no difference with the control group(p>0.05),indicating that NAC cleared the ROS induced by bergenin.6.Bergenin inhibited the expression of p-AKT and p-mTOR protein in colon cancer cells dose-dependently.7.The average mass and volume of the transplanted tumor of the bergenin group was(1.77 ± 0.43)g and(145 ± 28.12)mm3,which was(2.41 ± 0.21)g and(244.91 ±28.4)mm3 in the control group(p all<0.01).The inhibition rate of the bergerin group was 26.56%,and the tumor volume inhibition rate was 40.13%.8.There was no significant difference of total AKT and mTOR mRNA between the Bergenin group and the control group(p>0.05).The levels of p-AKT and p-mTOR protein in the transplanted tumor tissues of the bergenin group were significantly lower than that in the control group,which was(0.69±0.09)and(0.62±0.10)times of the control group(p<0.05).Conclusions:Bergenin has an inhibition effect on the PI3K/AKT/mTOR signaling pathway.It can inhibit proliferation,promote apoptosis,inhibit cell cycle progression,and induce DNA breakage injury and oxidative stress damage to play a protective role on colorectal cancer.