Correlation Between NPRL2 And Cinicopathological Features Of Bladder Cancer And Effect Of NPRL2 On Apoptosis Of Bladder Cancer Cells

Bladder cancer is one of the common malignant tumors,with increasing morbidity and mortality year by year^[1].The current clinical treatment of bladder cancer the preferred method for surgery and adjuvant chemotherapy.Although chemotherapy has a direct killing effect on cancer cells,it also causes certain damage to normal cells and is easy to relapse.Therefore,it is of great significance to reveal the molecular mechanism of the occurrence and development of bladder cancer and to search for targets for early diagnosis and treatment.NPRL2 was first discovered as a candidate tumor suppressor gene in lung cancer by bioinformatics method,consisting of 11 exons and encoding a protein of 380 amino acids^[2].This gene is highly expressed in normal tissues such as kidney,brain and liver^[3],while it is significantly down-regulated in various tumors such as breast cancer,lung cancer and colorectal cancer^[4-6].However,NPRL2 is highly expressed in some tumor cells,such as He La cells,Jurkat cells and HT29cells^[7-8].This group has been committed to research NPRL2 expression in urinary tract tumors and its potential clinical value,preliminary results showed NPRL2 abnormal high expression in prostate cancer,and and Gleason scores were positively correlated to the clinical stages,moreover also found interference NPRL2 PCa can affect cell proliferation and apoptosis,and influence the west he match of the prostate cancer cell toxicity^[9-11].The expression of NPRL2 in bladder cancer and its effect on bladder cancer cells are still unclear.This study aimed to investigate the expression of NPRL2 in bladder cancer cells and its effect on the proliferation of bladder cancer cells.ObjectiveTo investigate the correlation between expression of NPRL2 and clinicopathological features of bladder cancer and the effect of NPRL2silencing on the apoptosis of bladder cancer cell line Biu87/RT-4.MethodsClinical trials1.Cancer tissue specimens and related medical records of 131 patients with bladder cancer in the Department of Urology,the First Affiliated Hospital of Chongqing Medical University from January 2014 to January2019 were collected.2.The expression of NPRL2 in bladder cancer tissues was detected by immunohistochemistry,and the correlation between NPRL2 expression and clinicopathologic features of bladder cancer was analyzed.In vitro experiment1.The expression of NPRL2 in human normal bladder epithelial cell line CP-H068 and bladder cancer cell line BIU87/RT-4 were detected by RT-PCR and Western Blot.2.Lentivirus NPRL2 si RNA was transfected into bladder cancer cell line BIU87/RT-4.First,the transfection was successfully confirmed by fluorescence method,and then the m RNA and protein levels of NPRL2were detected in the transfected BIU87/RT-4 cell line respectively.3.CCK-8 method was used to detect the proliferation ability of transfected BIU87/RT-4 cell lines.4.Flow cytometry was used to detect the apoptosis.5.The protein expression of NPRL2 was detected by immunofluorescence assay.6.The apoptotic proteins of transfected cells were detected by RT-PCR and Western Blot.Data analysisSPSS 24.0 statistical software was used.Numeration data were expressed as x±s.Comparison between two groups was performed by t test,comparison between multiple groups was performed by one-way analysis of variance,and comparison between multiple groups was performed by SNKQ test,P< test.0.05 indicates that the difference is statistically significant.Results1.The results of clinical trials and immunohistochemistry showed that NPRL2 was highly expressed in bladder cancer tissues（53.44%）,which was significantly correlated with the clinical stage and grade of bladder cancer.2.Compared with the normal bladder epithelial cell line CP-H068,the expression of Nprl2 in bladder cancer cell BIU87/RT-4 was significantly increased.3.The proliferation ability of human bladder cancer cells BIU87/RT-4was significantly decreased after the expression of NPRL2 was interfered with.4.Interfering the expression of NPRL2 can effectively promote the apoptosis of human bladder cancer cell BIU87/RT-4.5.After the expression of NPRL2 was interfered,the expressions of apoptosis-related proteins JNK,Bax and Caspase-9 were increased,while the expression of Bcl-2 was inhibited.ConclusionThe expression of NPRL2 is related to the clinical stage and grade of bladder cancer.By silencing the expression of NPRL2 in BIU87/RT-4,the proliferation and apoptosis of bladder cancer cells can be effectively inhibited.