PTEN磷酸酶活性对人乳腺癌ZR-75-1细胞的迁移及粘着斑激酶磷酸化水平的影响

Effect of the phosphatase activity of PTEN on migration ability and FAK phosphorylation of human breast cancer cell line ZR-75-1

目的:探讨PTEN磷酸酶活性对ZR-75-1人乳腺癌细胞迁移及粘着斑激酶磷酸化水平的影响。方法:用有和无磷酸酶活性的两种PTEN表达质粒(W t和G 129)转染人乳腺癌细胞株ZR-75-1,用人工基底膜侵袭试验检测其转染前后的迁移能力,以W estern-b lot检测未转染的ZR-75-1和两种表达质粒的ZR-75-1磷酸化粘着斑激酶水平。结果:转染后有磷酸酶活性、无磷酸酶活细胞与未转染ZR-75-1细胞间侵袭抑制率、运动抑制率差异有显著性(P<0.01)。各组细胞间总FAK(粘着斑激酶)水平无明显差异,而W T-PTEN与G 129和ZR-75-1组FAK 397位酪氨酸磷化水平有明显差异。结论:PTEN具有抑制乳腺癌细胞ZR-75-1转移的作用,其机制可能与PTEN使FAK去磷酸化有关。

Objective： To explore the effect of the phosphatase activity of PTEN on migration ability and FAK phosphorylation of human breast cancer cell line ZR-75-1. Methods： WT-PTEN （wild type） plasmid encoding protein with phosphatase activity and G129 （PTEN plasmid encoding protein without phosphatase activity） were transfected respectively into breast cancer cell line ZR-75-1. The reconstituted basement membrane was used to detect the migration ability of the ZR-75-1 cells transfected with the plasmids before and 24h after the transfection. Western-blot analysis was used to detect the level of FAK phosphorylation of ZR-75-1 cells transfected with the plasmids or without. Results.. Compared with the control group （ZR-75-1 cells without transfection）, the cells transfected were inhibited in migration and adhesion abilities with significant difference between the WT-PTEN transfected cells and G129 transfected cells （P〈0.01）. The level of total FAK phosphorylation of Tyr residue at site 397 in WT-PTEN transfected cells was higher than cells of other two groups. Conclusion： PTEN could inhibit the migration ability of ZR-75-1 cells probably through the mechanism related to the dephosphorylation activity of FAK by PTEN.