PKIB Promotes The Proliferation And Metastasis In Bladder Urothelial Cancer Cells

Backgroud:Bladder urothelial carcinoma is a common malignant tumor in the urinary system,and its incidence ranks the second among the urinary tumors.Although,the clinic diagnosis and treatment of bladder cancer has been greatly improved,its recurrence rate and mortality are still not satisfactory.In particular,muscle-invasive bladder cancer(MIBC)has a high degree of malignancy,resulting in rapid clinical progression and poor prognosis among patients.A large amount of literature has shown that the uncontrollable tumors caused by early local progression and late distant metastasis are the main causes of death in patients with bladder cancer.Unfortunately,although a large number of targeted drugs have been developed,few have been shown to be effective against bladder cancer.As an Inhibitor of PKA(cAMP-dependent protein Kinase A),PKIB(cAMP-dependent protein Kinase Inhibitor-β)can influnce the activity of a series of Protein kinases and play an important role in various malignancies,such as prostate cancer and breast cancer,and is expected to become A therapeutic target for related tumors.Objective:To study the role of PKIB on the proliferation,apoptosis,migration and invasion of bladder cancer cells,and explore its mechanism preliminarily.To lay a theoretical foundation for the application of PKIB in the diagnosis and treatment of bladder cancer.Methods:1.The expression levels of PKIB in bladder carcinoma and paracancer tissues were detected by bioinformatics.2.Lentivirus was packaged by biological means to construct PKIB silencing cell lines and negative control cell lines.Their mRNA and protein expression levels of PKIB were analyzed by fluorescence quantitative PCR and Western Blotting.3.The proliferation ability of bladder cancer cells was detected by MTT and clonogenic experiments.And the apoptosis of bladder cancer cells was detected by apoptosis kit.4.Transwell assay was performed to evaluate the effect of PKIB on cell migration and invasion.5.Western and downstream gene rescue experiments were used to dectect and preliminarily verify the relevant target of PKIB in bladder cancer cells.Results:1.The GEPIA(http://gepia.cancer-pku.cn/)database and data from TCGA show that the expression level of PKIB in bladder cancer is significantly up-regulated.2.MTT and plate cloning experiments showed that the proliferation ability of cells decreased significantly after the knockdown of PKIB in T24 and 5637 cell lines.3.After silencing the expression of PKIB in cells,the apoptosis rate of T24 and 5637 cell lines increased significantly.4.After knocking down the PKIB gene,the migration and invasion capabilities of T24 and 5637 cell lines were inhibited.5.Silencing PKIB causes downregulation of other proteins,such as MMP2,NF-κB and p-NF-κB,while AKT,p-AKT and MMP9 were not significantly changed.Further,rescue experiments suggest that MMP2 is likely to be an important downstream gene for PKIB to function.Conclusions:PKIB has a stable cancer-promoting effect in bladder urothelial carcinoma,which may be achieved by activating the NF-κB/MMP2 pathway.