肿瘤抑制基因PTEN对人气道平滑肌细胞迁移和增殖的影响

Effects of Tumor Suppressor Gene PTEN on Migration and Proliferation of Human Airway Smooth Muscle Cells

目的观察肿瘤抑制基因PTEN对人气道平滑肌细胞(HASMCs)迁移和增殖的影响机制。方法用重组PTEN腺病毒转染体外培养的HASMCs(Ad-PTEN组),并与携带绿色荧光蛋白(GFP)的腺病毒空载体(Ad-GFP组)和空白对照(MOCK)组对比,采用MTS测定细胞增殖、Transwell法观察细胞迁移、共聚焦显微镜观测细胞骨架的变化、免疫印迹法检测PTEN、p-Akt、Akt、p-FAK、FAK蛋白的表达。结果 Ad-PTEN组的吸光度(A)值和每单位面积迁移的细胞数显著低于Ad-GFP及MOCK组(均P<0.05),Ad-GFP和MOCK两对照组间差异无统计学意义(P>0.05),提示过表达PTEN基因能抑制HASMCs的增殖和迁移的作用。Ad-PTEN组细胞轮廓变细,伪足及应力纤维明显变少,而Ad-GFP、MOCK组细胞有少量短而细的应力纤维,很少丝状伪足形成。与AdGFP及MOCK组比较,Ad-PTEN组p-Akt表达水平和FAK蛋白的磷酸化水平显著下调(均P<0.05),Ad-GFP及MOCK两对照组间差异无统计学意义(P>0.05),说明过表达PTEN能下调Akt蛋白和FAK蛋白的磷酸化水平。结论过表达PTEN可能通过下调p-Akt及p-FAK的表达,抑制HASMCs的增殖和迁移,参与哮喘气道重塑的调控。

Objective To investigate the mechanism for the effect of tumor suppressor gene PTEN on migration and proliferation of human airway smooth muscle cells （HASMCs）.Methods HASMCs were transfected with recombinant adenoviruses encoding human wild-type PTEN cDNA （Ad-PTEN group）,GFP-labeled adenovirus vectors （Ad-GFP group）and mock adenoviru-ses （MOCK group）,respectively.Cell proliferation was assessed by MTS assay.Cell migration was analyzed using Transwell chamber apparatus.The rearrangement of cell actin cytoskeleton was observed by laser scanning confocal microscope.The protein expression of PTEN,p-Akt, Akt,p-FAK and FAK were measured by Western blotting.Results Compared with Ad-GFP＆nbsp;group or MOCK group,the absorbance value,number of migrated cells per unit area and levels of p-Akt and p-FAK protein significantly decreased in Ad-PTEN group （P 0.05）.In addition,Ad-PTEN transfection diminished cell outline and reduced the pseudopodium and stress fibers.However,cells in Ad-GFP group and MOCK group had a small amount of short and thin stress fibers with few filiform pseudopodia.Conclusion The overex-pression of PTEN gene inhibits the migration and proliferation of HASMCs through down-regu-lating the expression of p-Akt and p-FAK.Therefore,PTEN may be involved in the regulation of airway remodeling in asthma.