Study On The Effects And Mechanisms Of Long Non-coding RNA MEG3 On Biological Behaviours In Bladder Cancer

Backgrounds:Lnc RNAs were initially regarded as genome transcription “noise” without any function.Recent studies reveals,although Lnc RNAs cannot encode proteins,they are involved in all aspects of biological regulation and can control the expression of gene through lots of signal pathway.Besides,their abnormal expressions are closely related with the occurrence and progression of a variety of diseases.Bladder cancer is the most common malignant tumor in urinary system,its high incidence and recurrence rate has always harassed urological surgeons so long and the causes are not very explicit.Therefore,exploring the molecular mechanisms of bladder cancer progression,seeking available biomarkers and effective therapeutic targets is significantly critical to improve the survival rates of patients with bladder cancer. The relationship between Lnc RNA and bladder cancer gradually attracts people's attentions,especially the significant upregulation of MEG3 in a wide variety of tumors,is considered to be a important tumor-suppressor gene,but its correlation with the occurrence and development of bladder cancer is as yet not clear.Purposes: 1.To detecet the expression level of long non-coding RNA MEG3 in bladdercancer tissues,and discuss its correlation with clinical stage and classification of bladder cancer; 2. Study on The Effects and Mechanisms of Long non-coding RNA MEG3 on Proliferation?Apoptosis?Epithelial-Mesenchymal Transition Invasion and Migrationin in Bladder Cancer.Methods: 1.To collect 35 cases of clinical patients who had undergone radical cystectomy,and extract the total RNA in tumor and adjacent normal tissues.Then the expression level of MEG3 was analyzed by QRT-PCR. 2. Long non-coding RNA MEG3 was significantlly downregulated by si RNA MEG3.To synthesize a full-length MEG3 sequence and then subclone it into a p CDNA vector for upregulating the expression level of MEG3.Constructed vectors and si RNAs MEG3 were respectively transfected into bladder cancer cells with Lipo 2000. 3.The effects of Long non-coding RNA MEG3 on Proliferation ? Apoptosis ?Epithelial-Mesenchymal Transition Invasion and Migrationin in Bladder Cancer:Cell survival rate was determined by MTT eassay,cell proliferation assessed by cloning formation experiment,cell apoptosis and cycle examined by flow cytometry,and Transwell was performed to evaluate cell invasion?migration. 4. Western Blot was performed to detect the expressions of Bcl-2?Bax?Cleaved caspase3?Cyclin D1?Vimentin?Snail?E-cadherin in bladder cancer cells treated with si RNA MEG3 or PCDNA-MEG3.Results: 1.There were totally 35 samples,27 of which came to downregulation(77.14%). The percentage of facial tumors with MEG3 downregulated was 55.56%,but when it came to invasive tumors,the percentage was 94.12%.MEG3 declined in 72.73% of the tissues without lymph node metastasis and the percentage of the other one was 75.00%.Eventually,the upregulation of MEG3 occurred in 81.25% samples without distant metastasis and in 66.67% tissues with distant metastasis. 2.With si RNA MEG3 interference to bladder cancer cells,the cell viabilities werestrengthed,the apoptotic rates of cells were reduced, the GO/G1 phase cells were significantly decreased,and the cell migration?invasion was increased.Since the bladder cancer cells transfected with p CDNA-MEG3,the results were completely on the contrary. 3. With si RNA MEG3 interference,the expressions were elevated among Bcl-2?Cyclin D1?Vimentin?Snail in bladder cancer cells,meanwhile, Bax ?Cleaved caspase3?E-cadherin was on the decrease. 4.With MEG3 overexpression,the expressions were decreased among Bcl-2?Cyclin D1?Vimentin?Snail in bladder cancer cells,meanwhile, Bax ?Cleaved caspase3?E-cadherin was on the increase.Conclusions: 1.Compared with adjacent normal tissues,the expression of MEG3 in tumor tissues was significantly downregulated,and the probability of MEG3 low expression was lower in facial tumor than invasive tumor.Besides,there was no obvious association between MEG3 expression and lymph node metastasis or distant metastasis. 2.MEG3 repressed the occurrence of EMT,exerted a negative effect on proliferation?migration?invasiveness in bladder cancer cells,and promoted the cell apoptosis. 3.MEG3 significantly inhibited the proliferation ? migration and invasion of bladder cancer cells through a variety of functional proteins.