ABSTRACT
Objective To evaluate the effect of resveratrol on the growth of an established A431 xenogratt tumor in nude mice.Methods The model of human skin squamous cell carcinoma was established by inoculating A431 cells in log-phase growth into the left axillary fossa of Balb/c (nu/nu) nude mice.After 7-8 days,60 mice bearing human A431 skin squamous cell carcinoma xenografts were randomly and equally divided into 6 groups:blank control group receiving no treatment,negative control group treated with intraperitoneal sodium chloride physiological solution,positive control group treated with intraperitoneal cyclophosphamide,high-,medium-and low-dose resveratrol groups treated with intraperitoneal resveratrol of 40,20 and 10 μg per gram body weight per day,respectively.Tumor size was measured at a 4-day interval during the treatment course.After 14-day treatment,the mice were sacrificed.Xenograft tumors were removed from these mice and subjected to weight measurement,pathological examination by hematoxylin and eosin (HE) staining and apoptosis detection by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL).Western blot was conducted to quantify the protein expression of apoptosis-related factors,including phosphorylated extracellular signal-regulated protein kinase (p-ERK),p53 and caspase 3.Data were processed by SPSS 13.0 software,and statistical analysis was carried out by analysis of variance and Pearson correlation analysis.Results By the end of treatment,the xenograft tumor volume was (1153.56 ± 255.41) mm3,(1001.69 ± 115.08) mm3,(1206.80 ± 175.88) mm3,(1342.28 ± 211.12) mm3,(1642.34 ± 225.85) mm3 and (1564.32 ± 156.49) mm3,and the weight was (1.84 ±0.30) g,(1.72 ± 0.39) g,(1.96 ± 0.40) g,(2.67 ± 0.73) g,(3.16 ± 0.52) g,and (3.33 ± 0.59) g,respectively in the positive control group,high-,medium-and low-dose resveratrol group,negative control group and blank control group.Significant differences were observed in the xenograft tumor volume (F =16.00,P ＜ 0.05) and weight (F =19.15,P ＜ 0.05) among the 6 groups.According to the tumor weight,the growth of tumor was inhibited by 45.57％,37.97％ and 15.51％ respectively in the high-,medium-and low-dose resveratrol groups.Increased apoptotic index was observed in the positive control group,high-,medium-and low-dose resveratrol groups compared with the negative control group and blank control group (36.79 ± 8.86,33.15 ± 6.00,18.09 ±3.92 and 10.53 ± 4.20 vs.3.87 ± 1.63 and 2.73 ± 1.61,F =93.26,P ＜ 0.05).Analysis of variance showed that the protein expressions of p-ERK,p53 and caspase 3 were all higher in the three resveratrol groups than in the negative control group and blank control group (F =6.65,6.78,11.56,respectively,all P ＜ 0.05).The protein expression of p53 was statistically correlated with p-ERK (r =0.68,P ＜ 0.05) and caspase 3 (r =0.56,P ＜0.05).Conclusions Resveratrol shows an inhibitory effect on the growth of human A431 skin squamous cell carcinoma xenografts in nude mice,likely by increasing p53 expression and inducing tumor cell apoptosis via the activation of MAPK/ERK pathway.
ABSTRACT
Objective To investigate the effects of pentoxifylline on the cell proliferation of, collagen synthesis and TGF-β1 expression by human fibroblasts derived from keloid. Methods Skin samples were obtained from the lesions of 3 patients with keloid and normal skin of 3 human controls followed by primary culture of fibroblasts. Fibroblasts of 5th to 8th generation were cultured with pentoxifylline of 0.1 to 3 g/L for various durations. Then, MTT assay was performed to detect the cell proliferation of fibroblasts, double antibody sandwich-enzyme linked immunosorbent assay (ELISA) to measure the expression of TGF-β1, and reversetranscription PCR to examine the mRNA expressions of procollagen Ⅰ and Ⅲ in these fibroblasts. Results The pentoxifylline of 0.1 to 2 g/L markedly inhibited the proliferation of fibroblasts derived from keloid lesions and normal skin, in a dose- and time-dependent manner, with the strongest effect observed in fibroblasts treated with pentoxifylline of 2 g/L. A significant reduction was induced in the TGF-β1 mRNA expression in keloidand normal skin-derived fibroblasts by pentoxifylline of 0.5 to 2 g/L (all P < 0.01), and in the mRNA expression of procollagen Ⅰ and Ⅲ by pentoxifylline of 1 and 2 g/L (P < 0.05 or 0.01). Concretely, the relative mRNA expression level of procollagen Ⅰ and Ⅲwas 0.873 ± 0.077, 0.571 ± 0.050 respectively in keloid fibroblasts respectively, and 0.473 ± 0.035, 0.370 ± 0.045 in the control fibroblasts, after treated with pentoxifylline of 1 g/L, 0.750 ± 0.036 and 0.433 ± 0.045 respectively in keloid-derived fibroblasts, 0.390 ± 0.030 and 0.250 ±0.123 respectively in the control fibroblasts, after treated with pentoxifylline of 2 g/L, significantly lower than that in the keloid-derived (1.216 ± 0.061 and 0.953 ± 0.060) and control (0.836 ± 0.080 and 0.776 ± 0.041) fibroblasts without treatment. Conclusion Pentoxifylline shows an evident suppressive effect on the cell proliferation of, as well as the expression of TGF-β1 and procollagen Ⅰ and Ⅲ in fibroblasts derived from keloid lesions and normal skin.
ABSTRACT
BACKGROUND:In recent years,pentoxifyIline has been found to have a wide range of anti-fibrosis capacity However,there are few studies explore the suppress effect of pentoxifyIline on fibroblasts in human keloid.and the maximum inhibitory concentration remains poorly understood.OBJECTIVE:To study the effect of pentoxifyIline on proliferation activity of human keloid fibroblasts and to select the maximum inhibitory concentrationMETHODS:Human keloid fibroblasts were used as original cells,passaged till the 5~(th) to the 8~(th) generations.and then divided into the experimental and control groups.PentoxifyIline with concentrations of 0.1,0.25,0.5,1.0,2.0 and 3.0 g/L were added to the experimental group.The effects of different concentrations of pentoxifylline on proliferation of keloid fibroblasts were detected by MTT chromometry.RESULT AND CONCLUSION:Compared with the control group,the inhibitory effect of pentoxifylline on the proliferation of keloid fibroblasts was more evident in the experimental group(P＜0.05)The inhibition rates of pentoxifylline on proliferation of keloid fibroblasts showed apparently time-and dose-effect relationships within the concentration of 0.1-2.0 g/L.which presented a greatest level at 96 hours after culture.The maximum inhibitory rate was 53 37%,and the concentration was 2.0 g/L in the experimental group.Consequently,pentoxifyIline plays a notable inhibitory role in the proliferation of human keloid fibroblasts with concentration of 2.0 g/L at 96 hours after culture.