二氢杨梅素通过调控鸟嘌呤核苷酸解离抑制因子2对结肠癌生长的抑制作用

Inhibition effect of the dihydromyricetin on the growth of colon cancer by regulating the expression of Rho-specific guanine nucleotide dissociation inhibitor 2

目的研究二氢杨梅素(DHM)对结肠癌生长的抑制作用及其可能机制。方法 (1)细胞实验:实验分4组:对照组(以2%胎牛血清处理SW480结肠癌细胞)、低、中、高3个剂量实验组(分别以10,20,40μmol·L^(-1)DHM处理SW480结肠癌细胞);以3-(4,5-二甲基吡啶-2-基)-5-(3-羧基甲氧基苯基)-2-(4-磺苯基)-2H-四唑(MTS)法检测SW480结肠癌细胞的增殖;以免疫印迹法检测SW480结肠癌细胞中鸟嘌呤核苷酸解离抑制因子2(RhoGDI2)蛋白的表达。(2)动物实验:在Balb/c裸小鼠右下肢皮下接种SW480结肠癌细胞悬液0. 2 mL构建移植瘤模型;按照体重将模型小鼠随机分4组:模型组、对照组(顺铂3 mg·kg^(-1))和低、高2个剂量实验组(20,60 mg·kg^(-1)DHM),每组5只;以免疫组化法检测结肠癌组织中RhoGDI2蛋白的表达。结果 (1)细胞实验:处理SW480结肠癌细胞1 d后,对照组和低、中、高3个剂量实验组对结肠癌细胞的抑制率分别为(2. 17±0. 53)%,(5. 83±1. 91)%,(16. 2±2. 82)%和(34. 51±1. 74)%;这4组的RhoGDI2灰度值分别为72. 16±2. 73,61. 39±3. 81,48. 76±3. 92和32. 39±3. 17。3个剂量实验组与对照组比较,上述指标差异均有统计学意义(P <0. 05,P <0. 01,P <0. 001)。(2)动物实验:模型组、对照组和低、高2个剂量实验组的RhoGDI2表达强度分别为8053. 60±236. 21,2791. 39±189. 72,6521. 28±172. 89和4381. 86±226. 33,低、高2个剂量实验组和对照组与模型组比较,差异均有统计学意义(P <0. 05,P <0. 01,P <0. 001)。结论 DHM能够抑制SW480结肠癌细胞的增殖和体内生长,其作用机制可能为抑制RhoGDI2蛋白的表达有关。

Objective To study the effect of dihydromyricetin DHM) on tumor growth of colon cancer and its potential mechanisms. Methods 1) Cell test: the cells were divided into four groups: control group SW480 colon cancer cells were treated with 2% fetal bovine serum) ; low-,middle-and high-dose experimental groups SW480 colon cancer cells were treated with 10,20 and 40 μmol·L^-1DHM,respectively) . The proliferation of SW480 colon cancer cell was detected by 3-4,5-diethylthiazol-2-yl)-5-3-carboxymethoxyphenyl)-2-4-sulfophenyl)-2H-etrazolium,inner salt MTS) . The protein expression of Rho-specific guanine nucleotide dissociation inhibitor 2 RhoGDI2) was detected by Western blot. 2) Animal test: Balb /c nude mice were injected subcutaneously with suspension of SW480 cells 2 × 10^7 cell·mL^-1 ) 0. 2 mL into the right hind to establish the tumors mice model. The model mice were randomized divided into four groups according to their weights: model group,control group 3 mg·kg^-1 cisplatin) ,experimental-L,experimental-H groups 20,60 mg·kg^-1 DHM) ,5 mice per group. The protein expression of RhoGDI2 was analyzed by immunohistochemical method. Results 1) Cell test: after treatment SW480 cells with DHM for 1 d,the inhibitory rates on the growth of colon cancer cell in control group,low-,middle-and high-dose experimental groups were 2. 17 ± 0. 53) %, 5. 83 ± 1. 91) %,16. 2 ± 2. 82) % and 34. 51 ± 1. 74) %,respectively; the gray value of the RhoGDI2 level in the 4 groups were 72. 16 ± 2. 73,61. 39 ± 3. 81,48. 76 ± 3. 92,32. 39 ± 3. 17, respectively. Comparison between three doses experimental groups and control group,the difference of the factors had significantly P < 0. 05 or P < 0. 01 or P < 0. 001) . 2) Animal test: The IOD of RhoGDI2 in the model group,control group,experimental-L group and experimental-H group were 8053. 60 ± 236. 21,2791. 39 ± 189. 72,6521. 28 ± 172. 89,4381. 86 ± 226. 33,respectively. Comparison between two doses experimental groups and control group with the model group,the difference had significantlyP < 0. 05 or P < 0. 01 or P < 0. 001) . Conclusion DHM can inhibit the proliferation and growth of SW480 colon cancer and the mechanism may be related to inhibit the expression of Rho GDI2.