中文摘要：

目的探讨低分子量肝素（low molecular weight hepa-rin,LMWH）对吉西他滨（gemcitabine,GEM）抗肿瘤作用的影响及其作用机制。方法实验分为对照组、LMWH组、GEM组、LMWH与GEM联合应用组。MTT法测定药物对MDA-MB-231、MDA-MB-435细胞增殖的影响;细胞划痕实验、Tr-answell小室法检测细胞的迁移和侵袭能力;Western blot检测基质金属蛋白酶-9（matrix metalloproteinase-9,MMP-9）的蛋白表达;ELISA法检测乳腺癌细胞培养液中乙酰肝素酶（heparanase,HPA）的表达。结果 LMWH对MDA-MB-231、MDA-MB-435细胞的增殖没有明显影响,亦不能增强GEM的增殖抑制作用。30×104IU·L-1LMWH与2.5 mg·L-1GEM联合作用于MDA-MB-231、MDA-MB-435细胞24 h的迁移抑制率分别为66.3%、76.5%,较单用GEM的迁移抑制率（MDA-MB-231细胞47.4%,MDA-MB-435细胞52.9%）明显提高。同时LMWH与GEM合用对乳腺癌细胞侵袭的抑制也明显高于GEM单用时的作用。GEM可下调MMP-9和HPA的表达,与LMWH合用时下调更加明显。结论 LM-WH具有增强GEM抑制乳腺癌细胞迁移和侵袭的作用,其机制可能与下调MMP-9和HPA的表达有关。

英文摘要：

Aim To investigate the anti-tumor effects of low molecular weight heparin（LMWH） combined with gemcitabine（GEM）,and to discuss the related mechanism.Methods Cells were divided into control group,LMWH group,GEM group and combined group.MTT assay was applied to evaluate the viability of MDA-MB-231 and MDA-MB-435 breast cancer cells.Wound healing assay and Transwell migration assay were performed to assess the effects of drugs on migration,and Transwell invasion assay was employed to evaluate the effects of drugs on invasion of breast cancer cells.The expression of matrix metalloproteinase-9（MMP-9） protein was analyzed by Western blot.ELISA was used to determine the expression of heparanase（HPA） in the culture medium.Results LMWH did not exhibit marked effect on the proliferation of MDA-MB-231 and MDA-MB-435 cells,yet it could not enhance the inhibitory effect of GEM on proliferation of the cells.LMWH combined with GEM resulted in enhanced inhibitory effect on migration and invasion compared with the individual use of GEM in MDA-MB-231 and MDA-MB-435 cells.At the same time,LMWH enhanced the down-regulation of MMP-9 and HPA expression induced by GEM.Conclusion LMWH can enhance the inhibitory effects of GEM on migration and invasion in breast cancer cells,which may be correlated to the down-regulation of MMP-9 and HPA.