瘦素对人乳腺癌MCF-7细胞迁移和侵袭的影响及其机制

The effect of leptin and its mechanisms on the migration and invasion of human breast cancer MCF-7 cells

目的探讨瘦素(leptin)对人乳腺癌MCF-7细胞迁移及侵袭能力的影响,并探讨其机制。方法 RT-PCR,Western blot法检测MCF-7细胞leptin受体(OB-R)的表达;Western blot法检测leptin(100 ng/mL)对MCF-7细胞信号通路分子p-ERK1/2,p-AKT,p-STAT3表达的影响;细胞划痕实验检测leptin对MCF-7细胞迁移能力的影响;TranswellTM细胞侵袭实验检测leptin对MCF-7细胞侵袭能力的影响;RT-PCR,Western blot法检测leptin对MCF-7细胞基质金属蛋白酶(MMP-9),转化生长因子β(TGF-β)表达的影响。结果 Leptin长短受体(OB-Rb,OB-Rt)在MCF-7细胞中均有表达;Leptin能显著上调MCF-7细胞p-ERK1/2,p-STAT3,p-AKT的表达(P<0.05);Leptin能促进MCF-7细胞的迁移及侵袭能力(P<0.05),JAK/STAT,PI3K/AKT信号通路抑制剂AG490(50μmol/L),LY294002(10μmol/L)能抑制leptin对MCF-7细胞的促迁移和侵袭作用(P<0.05),而MAPK/ERK通路抑制剂PD98059(10μmol/L)作用不明显(P>0.05);Leptin促进MCF-7细胞MMP-9,TGF-β的表达,AG490,LY294002能抑制其作用(P<0.05),PD98059对其无影响(P>0.05)。结论 Leptin可能通过JAK/STAT、PI3K/AKT信号通路上调MMP-9,TGF-β的表达促进MCF-7细胞迁移和侵袭。

Objective To investigate the effect and the relevant molecular mechanisms of leptin on the migration andinvasion of human breast cancer MCF-7 cells. Methods The expression of OB-R in MCF-7 cells was measured by RT-PCRand Western blotting. The effects of leptin （100 ng/mL） on the the phosphorylation of a few key cell signaling proteins,p-ERK1/2,p-STAT3, p-AKT in MCF-7 cells were examined by Western blotting. Cell scratch assay and Transwell^TM assaywere utilized to measure the effects of leptin on the migration and invasion capability of MCF-7 cells, respectively. The effectsof leptin on the mRNA and protein expression of matrix metalloproteinas 9 （MMP-9） and transforming growth factor β （TGF-β） were measured by RT-PCR and Western blotting. Results Both OB-Rb and OB-Rt were expressed in MCF-7 cells. Thisindicated that leptin may have significant activities in MCF7 cells. Indeed, leptin increased the phosphorylation of p-ERK1/2,P-STAT3,and p-AKT in MCF-7 cells （P〈0.05）. Further, leptin promoted migration and invasion of MCF-7 cells,which wereattenuated by the JAK/STAT inhibitor AG490 （ 50 μmol/L）, and the PI3K/AKT inhibitor LY294002 （10μmol/L） （P〈0.05）. Similarly, leptin also increased the mRNA and protein expression of MMP-9 and TGF-β,and these effects were blocked byAG490 and LY294002 as well （ P 〈 0.05）. Conclusion Leptin promoted the migration and invasion capabilities of MCF-7 cells. These activities may be achieved by the upregulation of MMP-9 and TGF-β through JAK/STAT and PI3K/AKT signaling pathways.