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Objective To investigate the effects and mechanism of lycopene on the proliferation and apoptosis of human hepatoma cell HepG2.Methods The human HepG2 cells in logarithmic growth phase were treated with lycopene (5,10,20 μg/ml) and cisplatin (40 pg/ml).The cellular growth inhibition rate was calculated by methyl thiazolyl tetrazolium (MTT) after 48 h,and cell cycle and apoptosis rate were analyzed by flow cytometry.The expressions of Bax,Bcl-2 and cleaved Caspase-3 proteins were detected by Western blotting.Results After 48 h intervention,the cellular growth inhibition rate of human HepG2 cell in blank control group was 0,and in lycopene (5,10,20 μg/ml) groups and cisplatin group were (21.3 ±4.2)％,(40.5 ±7.6) ％,(63.8 ± 9.1) ％,(37.8 ± 5.9) ％,with significant difference (F =37.905,P =0.000);and compared with blank control group respectively,the differences were statistically significant (t =208.124,P =0.000;t=394.637,P=0.000;t=628.592,P=0.000;t=257.168,P=0.000).The G0-G1 phase rates in lycopene (10,20 pg/ml) groups were (54.0 ± 2.9) ％ and (67.3 ± 3.6) ％,compared with blank control group (37.9± 1.5)％,the differences were statistically significant (t =4.508,P =0.024;t =10.673,P =0.006).The G2-M phase rates in lycopene (10,20 μg/ml) groups were (8.5 ± 0.6)％ and (4.7 ± 0.5)％,compared with blank control group (18.4 ± 0.8) ％,the differences were statistically significant (t =9.975,P =0.008;t =13.864,P =0.003).The apoptosis index (AI) in lycopene (5,10,20 μg/ml) groups and cisplatin group were (19.5 ± 4.8) ％,(43.0 ± 9.2) ％,(67.6 ± 10.1) ％ and (36.9 ± 6.8) ％,compared with blank control group [(3.6 ± 1.7)％],the differences were statistically significant (t =18.617,P =0.001;t =34.295,P =0.000;t =51.437,P =0.000;t =29.804,P =0.000).The expressions of Bcl-2,Bax and the ratio of Bax/Bcl-2 in lycopene (10,20 μg/ml) groups and cisplatin group were 0.42 ± 0.09,0.43 ±0.14,1.02 ±0.39;0.27 ±0.08,0.76 ±0.19,2.81 ±0.85;0.34 ±0.11,0.31 ±0.09,0.91 ±0.40,respectively.Compared with blank control group (0.59 ±0.17,0.18 ±0.06,0.31 ±0.12),the expressions of Bcl-2 were significantly down-regulated,and the differences were statistically significant (t =4.327,P =0.023;t =11.064,P =0.006;t =5.182,P =0.018),the expressions of Bax were significantly upregulated,and the differences were statistically significant (t =9.837,P =0.008;t =17.349,P =0.001;t =10.165,P =0.007),the ratios of Bax/Bcl-2 were significantly increased,and the differences were statistically significant (t=11.521,P=0.006;t=18.194,P=0.001;t=9.537,P=0.008).The expressions of cleaved Caspase-3 protein in lycopene (5,10,20 μg/ml) groups and cisplatin group were 0.25 ± 0.07,0.34 ±0.11,0.46 ± 0.18 and 0.17 ± 0.05,compared with blank control group (0.08 ± 0.03),the differenees were statistically significant (t =8.307,P =0.009;t =13.067,P =0.006;t =16.218,P =0.003;t =5.202,P =0.019).Conclusion Lycopene has inhibitive effect on the growth of human HepG2 cells perhaps through inhibiting proliferation and inducing apoptosis,which may be related to its effects of altering the cell cycle and the expressions of apoptosis-related genes and proteins.
ABSTRACT
Objective The objective of this study was to investigate effects of lycopene(LP) on the proliferation and apoptosis of human hepatocellular carcinoma HepG2 cells and to explore its mechanism.Methods HepG2 cells in logarithmic growth phase were treated with 0,5,10,20 μg/mL of LP and 40 μg/mL of Cisplatin for 48 h.Ten replicates in each dose were designed in this study.After treatments,the cell viability was measured by MTT colorimetric assay.The distribution of cell cycle was detected by flow cytometry(FCM).The mRNA expression of Bax and Bcl-2 were measured by RT-PCR.The expression of Caspase-3 protein was explored by Western blot.Results The inhibition rate of HepG2 cells was significantly increased by 10 μg/mL and 20μ g/mL of LP or 40 μg/mL of cisplatin when compared to the negative control group.The cell cycle of HepG2 cells were arrested at the G0/G1 phase and the apoptosis rate were significantly increased in comparison with the negative control group.The level of Bax mRNA expression was significantly increased and decreased in the expression of Bcl-2 mRNA.They were shown an increasing ratio of Bax/Bcl-2 and up-regulated Caspase-3 protein in HepG2 cells treated with LP.All effects in this study show a dose-dependent manner.Conclusion LP can inhibit the proliferation and promote the apoptosis in HepG2 cells.This mechanism may be contributed to arresting cell cycle and regulating gene expression related to apoptosis.
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Objective Islet transplantation has been an effective method for diabetes mellitus. The quality of donor pancreas is important for successful islet isolation. In this study, we evaluated expanded criteria donor usability based on the warm ischemic time, fatty pancreas and perfusion injury. Methods The marginal pancreases include those from cardiac death donor, fatty pancreas and edema pancreas from perfusion injury. Islets were isolated and purified using a modified University of Minnesota method. Islet yield and purity was determined by Dithizone (DTZ) staining and microscopic examination. Islet viability was assessed by AO/EB staining, and islet function was assessed by static glucose stimulation test. Results In the cardiac death donor group, the islet quality, viability, and in vitro function were similar when the warm ischemic time within 15 min. The quality and viability was decreased when the warm ischemic time beyond 30 min, but the function remained well. With 45 min warm ischemic time, insulin release index was decreased significantly. The islet quality, viability, and in vitro function from severe obesity group and severe edema group were decreased obviously. Conclusion Donor factors play a vital role in pancreas transplant outcomes. We concluded that pancreas severe obesity, severe edema and pancreas from cardiac donors (warm ischemic time ＞30 min) are unsuitable for islet isolation.