The Expression And Significance Of Long Non-coding RNA PVT1 And NEAT1 In ESCC

Background and Objective Esophageal cancer is a common malignant tumor whose motality rate and fatality rate ranks 6th and 8th.It is usually caused by unhealthy dietary habit.It has two histologic type:ESCC and EAC,among which ESCC is more common.EC is often detected by gastroscopy when patients show symptoms like dysphagia.However,it is often too late when these symptoms show up.The treatment for EC is still surgery at present,but surgery does not only bring pain and misery,but also may bring about complications like anastomotic leakage.So it’s of great importance to find a way for the early diagnosis of EC and treat EC in a less painful way like drugs or etc.Long non-coding RNAs are sequences about 200 nucleotides in length.Although they can not encode protein,they play critical roles in a wide range of cellular processes including regulation of gene expression,imprinting.chromatin modification,transcription and post translational processing.Therefore,we can infer that LncRNAs may play the role of regulation in the development and progression of tumor.LncRNA PVT1 is one of oncogenes,about 300 nucleotides in length.It is only 57 kb downstream from MYC,which is well-known to us.So it is not difficult to infer that PVT1 may regulate the occurrence and development of tumor because of that subtle relationship.NEAT1 is a LncRNA which is located in chromosome 1,and it has close relationship with many kinds of biological process like immune response,regulation the expression of gene and so on.Previous studies have proved its upregulation in many tumors such as neuroglioma leukemiabreast cancer laryngocarcinoma,Therefore,it was inferred to play vital roles in the occurrence and development of tumor.Most of researches focus on other tumors and rare of them on ESCC.The goal of my research is to investigate the difference in the expression level of long non-coding RNA PVT1 and CASC between tumor tissue and nomal tissue in ESCC patients,anaylse the underlying relationship between the expression level and patients’ pathologic stage and prognosis,to probe the probability of taking the two LncRNAs as new biomarker for the prognosis and treatment of ESCC.Methods 1 Different expression levels of NEAT1 and PVT1 in normal tissue and tumor tissue.1.1 54 operation samples including normal(5cm away from the edge of tumor)and tumor tissue were taken from the ESCC patients in Qingdao Medical University during 2015.6 to 2016.4 as research object,all patients had not been treated by radiotherapy nor chemotherapy,post operation pathogical result indicated ESCC.These samples were transferred to EP tubes as soon as possible,and then transferred to-80 ℃ ultra low temperature refrigerator for long time preservation.1.2 Extract RNA from tumor tissue and normal tissue using Trizol,using spectrophotometer to detect the purity and density of the exrtracted RNA.The purity of RNA in 1.8-2.0 is appropriate for next experiment,that not suitable RNA is extracted again until it fits the appropriate purity.Next we design primer sepatately upstream and downstream for the reverse transcription of PVT1 and NEAT1.Finding the overall sequence of the two LncRNAs though gene database at NCBI,then design the primer for PVT1 NEAT1 and internal control GAPDH by online primer designer from Standford University.Taking GAPDH as control and then perform reverse transcription.Detecting the expression level of PVT1 and NEAT1 in normal and ESCC tumor tissue.At last we use SPSS19.0 to analyse the relationship between the expression level of the two LncRNAs and TNM stage of EC with the combination of clinical data we collected.2 Find and extract data collected from TCGA to discover the relationship between the expression level of the two LncRNAs and the survival.Results 1 The expression level of Long non-coding RNA PVT1 and NEAT1 in tumor tissue is significantly higher than that in normal tissue(P<0.05).2 The expression level of PVT1 and NEAT1 each has obvious connection with lymph nodes metastasis,tumor differentiation degree and TNM stage(P<0.05),but with little relationship with age and gender and the location of tumor(P>0.05).3 Kaplan-Meier analysis shows that the 5 year survival rate is shorter in PVT1 and NEAT1 up-regulated group than that in down-regulated group(P<0.05).Conclusion 1 The expression level of PVT1 and NEAT1 is significantly higher in tumor tissue than in normal tissue.2 Over expressed PVT1 and NEAT1 indicates an advanced TNM stage and poor prognosis.3 LncRNA PVT1 and NEAT1 has a close relashionship with the occurence and development of ESCC.PVT1 and NEAT1 may serve as a new biomarker for the prognosis and treatment of ESCC.