LncRNA-SNHG7 Regulates Proliferation,Apoptosis And Invasion Of Bladder Cancer Cells

Bladder cancer is a malignancy that occurs in the bladder mucosa.It is the most common malignant tumor of the urinary system,but also one of the top ten common tumors in humans.It shows the highest incidence of genitourinary tumors in our country,while its incidence in the West is second only to prostate cancer[1].Bladder cancer can occur at any age,even in children.Its incidence increases with age.The pathological types of bladder cancer include bladder urothelial carcinoma,bladder squamous cell carcinoma,adenocarcinoma of the urinary bladder,and the rare bladder subtypes like clear cell carcinoma,bladder small cell carcinoma and bladder carcinoid.One of the most common is bladder urothelial carcinoma,accounting for more than 90%of the total number of patients with bladder cancer[2].Although the various surgical methods and radiotherpy and chemotherapy methods has been improned,the recurrence rate is still high and five-year disease-free survial rate is low,especially in the high-grade muscle invasion of bladder cancer.It is of great theoretical and practical significance to clarify thd pathogenesis of bladder cancer and to find valuable tumor markers and new therapeutic targets for guiding the clinical treament and predict the prognosis of tumor.Recently,A growing number of basic studies of bladder cancer have focused on the study of tumor genes and their coding products.The purpose is to be able to detect bladder cancer early,guide clinical treatment,determine the prognosis of the disease,and monitor the recurrence of the disease after surgery.As a target for treatment,it can improve the therapeutic effect of bladder cancer.But the bladder cancer occurrence and progress of molecular mechanism has been unclear recently.From the pathogenesis of bladder cancer,it is of great significance to study the development of bladder cancer at the molecular level and to the diagnosis and treatment of bladder cancer.Long-chain non-coding RNAs(LncRNAs)are non-coding RNAs>200 nucleotide(nt)in length that are involved in the development of various diseases[3,4]Up to date,many researchers found that LncRNAs are abnormally expressed in many malignant tumors and are closely related to tumor cell proliferation,apoptosis and invasion.For instance,Wang et al.found that LncRNA-SNHG7 was highly expressed in gastric cancer tissues and was closely related to proliferation,apoptosis,invasion and metastasis of gastric cancer cells[5]AndShe et al.found that LncRNA-SNHG7 had high expression in lung cancer tissues and inhibited the apoptosis of lung cancer cells by inhibitedthe expression of LncRNA-SNHG7[6].However,the current level of expression of LncRNA-SNHG7 in bladder cancer and its function is still unclear.This article focused on LncRNA-SNHG7 expression in bladder cancer tissues and cell lines to explore its impact on bladder cancer cell proliferation,apoptosis and invasion processes,and to provide a strong theoretical basis for clinical diagnosis and treatment.This study is divided into three parts:Part I:Theexpression of LncRNA-SNHG7 in bladder cancer tissue.Purpose:At present,several experimental studies have confirmed the high expression of LncRNA-SNHG7 in tumors,affected the proliferation,apoptosis,invasion and migration of tumor cells.The purpose of this study was to study the expression of LncRNA-SNHG7 in bladder cancertissues.Methods:A total of 87 cases of bladder cancer tissues were collected,and the normal bladder tissue samples were treated as control group.The expression of c in bladder cancer tissues was detected by real-time quantitative polymerase chain reaction(RT-PCR).The minimum significance difference method(post hoc test)of one way anova test was used as the comparison between tow groups.The correlation between clinical factors of LncRNA-SNHG7 and bladder cancer tissue was analyzed by chi-square test.Results:Compared with normal urothelial tissue,LncRNA-SNHG7 was highly expressed in bladder cancer tissues and bladder cancer cells.The largest of the bladder tumor,the most expression of LncRNA-SNHG7 in bladder cancer tissues(P=0.000).The proportion and expression level of LncRNA-SNHG7 in muscular invasived bladder cancer was higher than that of non-muscular invasived bladder cancer(P=0.014).The expression levels of LncRNA-SNHG7 in metastatic bladder cancer was higher than in non-metastatic bladder cancer(P=0.000).Conclusions:This study showed that LncRNA-SNHG7 is overexpressed in bladder cancer tissues and cells.and itis closely related to thetumor size,clinical stage and tumor metastasis.Part II:LncRNA-SNHG7 regulates the proliferation and apoptosis of bladder cancer cellsPurpose:The purpose of this study was to investigate the expression of long-chain non-coding RNA(LncRNA)SNHG7 in bladder cancer cell lines,and to explore its impact on bladder cancer cell proliferation,apoptosis and invasion processes.Methods:Thebladder cancer cell lines(SW780 and J82)and normal bladder cells(SV-HUC-1)were cultured in vitro.The expression of LncRNA-SNHG7 in tissues and cell lines was detected by real-time PCR(RT-PCR).The expression of LncRNA-SNHG7 was downregulated by RNA interference(siRNA)as detected by RT-PCR that was used to detect the interference efficiency.CCK-8,and flow cytometry were used to evaluate the effect of LncRNA-SNHG7 on the proliferation,apoptosis of bladder cancer cells.Results:LncRNA-SNHG7 was upregulated in bladder cancer cell lines(p<0.05)After the siRNA LncRNA-SNHG7 and si-NC were transfected into cells,the expression of LncRNA-SNHG7 was downregulated(p<0.05),the proliferation of bladder cancer cells was decreased,and the apoptosis was increased.Conclusions:This study showed that LncRNA-SNHG7 is overexpressed in bladder cancer cells.Downregulation of LncRNA-SNHG7 can inhibit the proliferation of bladder cancer cells and promote apoptosis,which provides a potential molecular target for future tumor targeted therapy.PartⅢ:LncRNA-SNHG7 regulates the invasion of bladder cancer cellPurpose:To investigate the relationship of long-chain non-coding RNA(LncRNA)SNHG7 in bladder cancer cell lines and epithelial-mesenchymal transition(EMT),and to explore its impact on bladder cancer cell invasion of bladder cancer cells.Methods:Thebladder cancer cell lines(SW780 and J82)and normal bladder cells(SV-HUC-1)were cultured in vitro.After the siRNA LncRNA-SNHG7 and si-NC were transfected into cells,Transwell assays were used to evaluate the invasion capability of bladder cancer cells.The expression of EMT molecular markers,like e-cadherin,n-cadherin,vimentin and snail,were detected by Western blot.And the downregulation effect of LncRNA-SNHG7 on epithelial-mesenchymal transitionrelated markers was also tested by western blot.Results:Compared to the control group,LncRNA-SNHG7 was upregulated in bladder cancer cell lines.After the expression of LncRNA-SNHG7 was downregulated,the invasion ability of cells was decreased.And the expression of E-cadherin was increased,but the expression of N-cadherin,vimentin and snail were decreased.Conclusions:Downregulation of LncRNA-SNHG7 can inhibit the EMT progression and migration of bladder cancer cells,as well as inhibit cell invasion,which provides a potential molecular target for future tumor targeted therapy.