Expressions And Significances Of Long Non-coding RNA HOTAIR、MEG3 And P53、MDM2 In Human Gastric Cancer

Objective:Gastric cancer(GC)is one of the major tumors that are harmful to human health,which is also a major cause of human death.It ranks second in the causes of cancer-related deaths.Because of the lack of specificity of early symptoms of gastric cancer patients,early detection and diagnosis of gastric cancer is difficult.In general,it is in the middle and late stages when diagnosed.Therefore,it is of great value to find meaningful molecular markers for early diagnosis and treatment of gastric cancer.Long non-coding RNA(Lnc RNA)is a kind of RNA that does not encode protein itself.It acts as RNA to regulate gene expression through epigenetics,transcription,and post-transcriptional regulation.It plays an important role in the occurrence and development of tumors and is currently the focus of tumor research.At present,little is known about the expression of long-chain non-coding RNA HOX transcript antisense RNA(HOTAIR)and maternal gene 3(MEG3)in gastric cancer.The purpose of this study was to examine the expression levels of lnc RNA,HOTAIR and MEG3 in GC tissues,and to explore the relationship between their expression and clinicopathological features in 50 specimens of gastric cancer patients.The relationship between MEG3 and p53,MDM2 was analyzed to study its mechanism of action.Methods:From october 2015 to October2016,we have included 50 Patients with GC admitted to Qingdao Municipal Hospital for surgery into our study.We collect GC tissues and paired normal tissues(More than 5cm away from cancer tissues).We tested the expression of HOTAIR 、 MEG3,by Real-time fluorescence quantitative PCR(qRT-PCR),Combined with pathological data to analyze its relationship with clinicopathological features,and We tested the expression levels of p53 and MDM2 in gastric cancer and paired normal tissues by Western blot and to analyze their correlations with MEG3.Results:1.The expression level of HOTAIR was increased in GC tissues(6.97±0.18)relative to paired normal tissues(4.72±0.18)(P<0.05).The expression level of MEG3 was decreased in GC tissues(7.25±0.17)relative to paired normal tissues(9.36±0.19),(P<0.05).2.The expression level of HOTAIR and MEG3 has no correlation with the patient’s age,gender,tumor size,it is related to the degree of differentiation,whether have lymph node metastasis or not and TNM stage(P<0.05).3.The expression of p53 was decreased in GC tissues(0.1832±0.0135)compared to normal tissues(0.2476±0.0164)(P<0.05).The expression level of MDM2 was increased in GC tissues(0.2871±0.0166)compared to paired normal tissues(0.1855±0.0152)(P<0.05).4.It showed that there were positive correlations between MEG3 and p53(r=0.621,P<0.05),and there were negative correlations between MEG3 and MDM2(r=-0.352,P<0.05).Conclusions: HOTAIR plays an oncogenic role in the development of gastric cancer,MEG3 plays an inhibition role in the development of GC,and MEG3 may play a carcinogenic role through regulating the p53 pathway.To test the expression of HOTAIR and MEG3 have a important value for the early diagnosis,therapy and prognosis of GC.