前列腺特异性膜抗原新型剪接变异体PSM-E对前列腺癌细胞骨转移的作用

摘要

目的 探讨前列腺特异性膜抗原(PSMA)新型剪接变异体PSM-E对前列腺癌细胞(RM-1)骨转移的作用及其机制.方法 脂质体将PSM-E、PSMA基因转染RM-1,构建细胞模型(RM-1-PSM-E、RM-1-PSMA),检测羧肽酶活性；黏附及迁移实验测定不同细胞在骨基质胶模型上的黏附及迁移能力；Western blot检测不同细胞中粘着斑激酶(FAK)的表达及磷酸化水平.结果 与转染空质粒的RM-1比较,RM-1-PSM-E、RM-1-PSMA的羧肽酶活性分别升高1.96倍和2.13倍,而黏附能力分别升高12倍和14倍,加入羧肽酶活性抑制剂后,RM-1-PSM-E、RM-1-PSMA的黏附能力分别降低2.6倍和3.5倍；与转染空质粒的RM-1比较,RM-1-PSM-E、RM-1-PSMA的迁移能力降低,且FAK的磷酸化水平分别升高1.47倍和1.66倍.结论 PSM-E对前列癌细胞骨转移具有调控作用,这与PSM-E的酶活性及FAK磷酸化水平有关.%Objective To study the effect and mechanism of prostate specific membrane E (PSM-E) regulating bone metastasis of prostate cancer cells.Methods PSM-E or prostate-specific membrane antigen (PSMA) was transfected into RM-1 with liposome and their enzymatic activity was measured.The ability of adhesion and migration of tumor cells was detected by using attachment and migration assay.The expression of FAK protein and its phosphorylation status were examined by using Western blotting.Results Compared with control,the carboxypeptidase activity of RM-1-PSM-E and RM-1-PSMA had 1.96-fold and 2.13-fold increase respectively,and the adhesion ability of RM-1-PSM-E (12-fold) or RM1-PSMA (14-fold) was enhanced.After treatment with the inhibitor of carboxypeptidase activity,the adhesion ability had 2.6-fold or 3.5-fold decrease,the migratory ability of RM-1-PSM-E or RM-1-PSMA was weakened,and higher level of FAK phosphorylation was detected in RM-1-PSM-E (1.47-fold) or RM-1-PSMA (1.66-fold).Conclusion PSM-E could regulate bone metastasis of prostate cancer cells,which may be correlated with its enzymatic activity and the level of FAK phosphorylation.