次声对小鼠结肠癌生长影响及其机制的探讨

Effect of infrasound on the growth of colorectal carcinoma in mouse

目的:研究次声暴露对离体及在体小鼠结肠癌CT26细胞生长的影响。方法:离体实验将小鼠结肠癌CT26细胞接种后分为对照组、8Hz/130dB组和16Hz/130dB组;在体实验将小鼠结肠癌CT26细胞接种于BALB/c小鼠皮下建立动物模型后,分为对照组、8Hz/100dB组和16Hz/100dB组。每天均暴露2h,连续7d。离体细胞每天干预后采用MTT法检测细胞增殖活性;动物模型于暴露第7天摘除小鼠眼球留取血液标本,并处死后留取肿瘤组织,观察移植瘤大体形态和组织病理学改变,计算抑瘤率;免疫组化法测定凋亡相关蛋白Caspase-3的表达情况;酶联免疫法测定血清癌胚抗原(CEA)水平。结果:1)离体8Hz/130dB组及16Hz/130dB组与对照组相比结肠癌CT26细胞增殖活性在暴露d3～d6时均明显降低,P<0.05。2)在体8Hz/100dB组、16Hz/100dB组小鼠结肠癌移植瘤出现坏死性病理变化。3)在体Caspase-3表达阳性着色于细胞核呈褐色,16Hz/100dB组的Caspase-3表达明显高于对照组,P<0.05;16Hz/100dB组血清CEA水平(1 901.92±362.82)ρg/mL较对照组明显降低(3 929.14±2 934.33)ρg/mL,P=0.041。结论:8Hz/130dB、16Hz/130dB次声暴露可抑制离体结肠癌CT26细胞的增殖;16Hz/100dB可致在体小鼠结肠癌移植瘤坏死;16Hz/100dB可促进在体结肠癌CT26细胞的凋亡,降低小鼠体内血清CEA水平。

OBJECTIVE：To study the effects of infrasound exposure on colon cancer in BALB/c mice. METHODS： Mice colon cancer cell CT26 was cultured, and divided to three groups： control group, 8 Hz/130 dB and 16 Hz/130 dB groups. In vivo,CT26 cells were subcutaneously injected in male BALB/c mice and also divided to three groups：control group,8 Hz/100 dB and 16 Hz/100 dB groups. Every group both in vitro and in vivo was exposed to infrasound environ- ment 2 h a day for 7 days. After infrasound exposure,proliferation activity of cultured CT26 cells was measured in vitro by MTT method. Blood specimen was obtained from mice eyeball and transplanted tumor was removed and tumor volume and weight were measured. The inhibition rate was calculated; the expression of Caspase-3 protein were measured by the immunhistochemistry assay; serum CEA was measured in vivo by ELISA method. RESULTS： 1）Compared with controls, the proliferation activity in vitro was lower in 8 Hz/130 dB and 16 Hz/130 dB group than that in control group （P〈0.05）. 2）Necrosis of transplanted tumor cells in vivo was found in 8 Hz/100 dB and 16 Hz/100 dB groups. 3）Caspase-3 clored with bromnish and was higher expression in 16 Hz/100 dB group than that in control group in vivo （P〈0. 05）. Ser- um CEA level was lower in 16 Hz/100 dB group（1 901.92±362.82） pg/mL than that in control group （3 929. 14±2 934.33） pg/mL in vivo （P=0. 041）. CONCLUSIONS：The growth of CT26 in vitro can be inhibited after 8 Hz/130 dB and 16 Hz/130 dB infrasound exposure. Necrosis of transplanted tumor cells can be caused after 8 Hz/100 dB and 16 Hz/ 100 dB infrasound exposure. Apoptosis of transplanted tumor cells and decrease serum CEA level can be promoted after 16 Hz/100 dB infrasound exposure.