Study On The Expression And Function Of Long Non-coding RNA NORAD In Esophageal Squamous Cell Carcinoma

Part one The expression and clinical significance of lncRNA NORAD in esophageal squamous cell carcinoma tissuesObjective: To detect the expression levels of long non-coding RNA(lncRNA)non-coding RNA-activated by DNA damage(NORAD)in esophageal squamous cell carcinoma(ESCC)tissues,and to analyze the potential relationships between lncRNA NORAD expression and clinic-pathological features of ESCC patients.Methods: 30 ESCC tissues and the adjacent cancer tissues were collected from patients whose pathological diagnosis was confirmed in the Department of Thoracic Surgery,Fourth Hospital of Hebei Medical University between March and June,2019.Quantitative real-time polymerase chain reaction(q RT-PCR)method was used to detect the expression of lncRNA NORAD in ESCC tissues.The relationships between the expression levels of lncRNA NORAD and clinic-pathological features were analyzed.Results: The expression of lncRNA NORAD in ESCC tissues was significantly higher than that in adjacent tissues(P < 0.05).The expression of lncRNA NORAD was significantly higher in tumor tissues with TNM stage(III-IV),poor histology differentiation and positive lymph node metastasis than that with TNM stage(I-II),well or moderate differentiation,and negative lymph node metastasis(P < 0.05,respectively).While there were no significant difference between the expression of lncRNA NORAD and age,gender,oralcohol consumption history of patients(P > 0.05).Conclusions: lncRNA NORAD was highly expressed in ESCC tissues.The expression of lncRNA NORAD was correlated significantly with histology differentiation,lymph node metastasis and histology TNM stage.Part two The mechanism of lncRNA NORAD promoting migration of EC9706 cells in esophageal squamous cell carcinomaObjective: To detect the effects of lncRNA NORAD on the proliferation and migration of EC9706 cells and the related mechanisms.Methods: Reverse transcription-polymerase chain reaction(RT-PCR)was used to detect the expression levels of lncRNA NORAD in different ESCC cells(TE1,YES-2,EC9706 and KYSE150)respectively.Small interfering RNA(si RNA)targeting lncRNA NORAD gene was transfected into EC9706 cells(as si-NORAD group)by RNA interference technique to knockdown lncRNA NORAD expression,as well as EC9706(as Con group)and si RNA negative control transfected group(as NC group).q RT-PCR was used to detect the transfection efficiency.MTT,colony formation assay and scarification tests were used to detect the ability of proliferation,and migration of EC9706 cells before and after lncRNA NORAD knockdown.Western blotting was used to detect the expression of E-cadherin,N-cadherin and Snail in EC9706 cells before and after lncRNA NORAD knockdown.Results: lncRNA NORAD was highly expressed in different ESCC cells.After transfection of NORAD-si RNA into EC9706 cells,the expression of lncRNA NORAD was down-regulated significantly(P < 0.01).Comparing with Con and NC groups,the proliferation and migration abilities were decreased in si-NORAD group(P < 0.05).Furthermore,the expression of E-cadherin was up-regulated while the N-cadherin and Snail were down-regulated in si-NORAD group(P < 0.01),while there was no difference between Con and NC groups(P >0.05).Conclusions: lncRNA NORAD was expressed in different ESCC cells.Knockdown of lncRNA NORAD could significantly inhibited the proliferation and migration abilities of EC9706 cells.lncRNA NORAD could induce the epithelial-mesenchymal transition through up-regulating N-cadherin and Snail expression and down-regulating E-cadherin expression,thereby promoting malignant biological behavior of EC9706 cells.