VEGF-C基因表达下调对乳腺癌增殖及淋巴转移抑制作用研究

Inhibition of proliferation and lymphatic metastasis of breast cancer by down-regulating the expression of VEGF-C

目的利用RNA干扰技术特异性抑制乳腺癌MCF-7细胞中血管内皮生因子C(vascular endothelial growth factor C,VEGF-C)的基因表达,体内外实验研究下调VEGF-C后对乳腺癌增殖及淋巴结转移的影响。方法利用重组质粒pSIREN-VEGF-C转染乳腺癌MCF-7细胞并筛选稳定表达细胞株,观察转染前后MCF-7细胞中VEGF-C基因的表达情况及对细胞增殖的影响;以稳定表达细胞株建立乳腺癌裸鼠原位移植瘤模型并观察下调VEGF-C基因后对肿瘤淋巴管生成及肿瘤生长转移的影响。结果转染重组质粒后乳腺癌MCF-7细胞中VEGF-C mRNA及蛋白表达均明显下调,抑制率分别为95%(P<0.001)和100%,P=0.018。转染后的MCF-7细胞增殖明显受抑制,P<0.05。转染细胞移植瘤的淋巴管生成明显减少,重组质粒组移植瘤中的LMVD为18.23±1.56,较空白对照组的34.50±1.13明显减少,P<0.001;生长速度较对照组缓慢,重组质粒组平均成瘤时间为(14.00±2.13)d,较空白对照组(7.92±1.95)d时间长,P=0.021;重组质粒组肿瘤体积为(706±58)mm3,低于空白对照组(1 285±262)mm3,P=0.020;重组质粒组的转移淋巴结数目为0.45±0.23,明显低于空白对照组1.50±0.45,P=0.021。结论表达VEGF-C shRNA的重组质粒载体pSIREN-VEGF-C在体内外均能高效、特异地发挥靶基因沉默作用,并对乳腺癌细胞的增殖及淋巴转移有显著抑制作用。

OBJECTIVE To explore the efficacy of vascular endothelial growth factor C（VEGF-C） on the prolifera- tion and lymphatic metastasis of human breast cancer. METHODS Stably knockdown VEGF-C cell line was established by transfecting recombinant vector （pSIREN-VEGF-C） into human breast cancer cell MCF-7. Xenograft mouse model was used to determine the effect of VEGF-C on the lymphangiogenesis and metastasis in vivo. RESULTS Significant re- duction of VEGF-C expression, both on mRNA and protein （inhibitory rate was 95%, P〈0. 001, 100%, P=0. 018, re- spectively） was obtained in stably knockdown VEGF-C cells. These ceils also displayed marked repression of proliferation （P〈0.05）. Mice with stably knockdown VEGF-C cells xenografted showed decreased lymphangiogenesis （18.23 ± 1.56 vs 34.50±1.13, P〈0. 001） slower formation of tumor[（14.00±2.13）d vs （7. 92±1.95） d, P=0. 021], smaller vol- ume of tumor[（706±58） mm^2 vs （1 285±262） mm^2 , P=0. 020] and less metastasis （0.45±0.23 vs 1.50±0.45, P= 0. 021） compared to controls. CONCLUSION Knocking down VEGF-C by transfecting recombinant vector （pSIREN- VEGF-C） leads to significant inhibition of proliferation and lymphatic metastasis in breast cancer.