双歧杆菌脂磷壁酸对不同大肠癌细胞株转移能力及VEGF表达的影响

Lipoteichoic acid of Bifidobacterium down-regulates VEGF expressions and inhibits the metastasis of colon carcinoma

目的研究双歧杆菌脂磷壁酸(lipoteichoic acid,LTA)对血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)表达及其对大肠癌细胞株侵袭、转移能力的影响。方法采用噻唑蓝比色(MTT)法检测经双歧杆菌LTA处理前后大肠癌细胞株LoVo和HT-29对人工基底膜(Matrigel)的黏附能力变化;Transwell小室体外侵袭迁移实验检测经LTA处理前后两株细胞侵袭、迁移能力的改变。RT-PCR和Western blot检测经LTA作用前后,VEGF在两株细胞中的表达差异。结果经20、50、80μg/ml双歧杆菌LTA处理后,LoVo细胞和HT-29细胞在30、60、90、120min时的黏附率明显低于对照组(P<0.01);经50μg/ml双歧杆菌LTA处理24h后,LoVo细胞和HT-29细胞的侵袭能力及VEGF的mRNA和蛋白质的表达,与对照组比较有显著性差异(P<0.01)。结论双歧杆菌LTA能抑制大肠癌细胞黏附、侵袭、迁移的能力,下调其VEGF的mRNA和蛋白质的表达。

Objective To study the effect of lipoteichoic acid （LTA） of Bifidobacterium on the expression of vascular endothelial growth factor （VEGF） and invasion and metastasis of colon carcinoma cell lines. Methods The effects of LTA on adhesion, invasion and metastasis of human colon carcinoma lines LoVo and HT-29 in vitro were examined by MTT colorimetric and transwell chamber. The mRNA and protein expressions of VEGF in the two colon carcinoma cells treated with LTA were detected by RT-PCR and Western blot. Results The adhesion ability decreased in LoVo cells and HT-29 cells after the treatment of LTA （20, 50, 80 μg/ ml） for 30, 60, 90, 120 min （P 〈0.01 ）; The invasion ability as well as VEGF mRNA and protein expres- sions decreased after 50 μg/ml LTA treatment in the two carcinoma cells （ P 〈 0.01 ）. Conclusion LTA of Bifidobacterium can inhibit the ability of adhersion, invasion and metastasis of colon carcinoma cell lines and down-regulate the expressions of VEGF.