Heparanase表达下调对结肠癌细胞增殖和侵袭的影响

目的 探讨乙酰肝素酶（Heparanase）对结肠癌细胞生物学功能的影响。方法 采用荧光定量PCR检测人结肠癌细胞株SW620、SW480、LoVo和CACO 2中Heparanase的表达水平；设计并合成3条Heparanase特异性的小分子干扰RNA（siRNA1、siRNA2、siRNA3），用于转染4株结肠癌细胞中Heparanase表达水平最高者；荧光定量PCR和Western blotting检验3条siRNA的干扰效果；MTT法检测结肠癌细胞的增殖能力；Transwell小室法检测结肠癌细胞的侵袭能力。结果 SW480细胞中Heparanase的表达水平高于其他3株结肠癌细胞；3条特异性siRNA转染SW480细胞后，均能在蛋白和mRNA水平抑制Heparanase的表达，以siRNA3的效果最佳，且呈剂量依赖性。siRNA3介导的Heparanase基因沉默可呈剂量依赖地降低SW480细胞的增殖能力并减弱侵袭能力（P＜0.05）。结论 Heparanase表达下调可导致结肠癌细胞生物学恶性程度降低，提示Heparanase可作为结肠癌靶向治疗的一个重要靶点。

Effects of heparanase expression reduction on proliferation and invasion of colon cancer cell lines

Objective To investigate the effect of heparanase expression reduction on biological behavior of colon cancer cell lines. Methods Hcparanase expression levels of four colon cancer cell lines （SW620, SW480, LoVo and CACO-2 ） were measured by real-time PCR. Three heparanase-speeifie small interfering RNA （siRNA1, siRNA2 and siRNA3 ） were designed, synthesized and transfeeted into the cell line with the highest expression of heparanase among the 4 colon cancer cell lines. The heparanase expression was measured by real-time quantitative PCR and Western blotting. Cell proliferation was detected by MT＇F colorimetry. The in vitro cell invasion was detected by transwell chamber method. Results The expression of heparanase in SW480 cell line was higher than the other 3 cell lines. Transfection of the 3 specific siRNAs could reduce the expression of heparanase at protein and mRNA levels, espe- cially siRNA3 in a dose-dependent manner. The siRNA3-mediated silence of heparanase suppressed the proliferation of SW480 cells, and the in vitro invasion of SW480 cells was attenuated in a dose-dependent manner. Conclusion Gene silence of heparanase can effi- ciently abolish the malignant biological behavior of colon cancer cell lines in vitro, suggesting that heparanase could be regarded as a novel target for gene therapy of colon cancer.