The Study Of Expression And Diagnostic Value Of Long Non-coding RNA MALAT1 In Gastric Cancer

Background and objectiveThe gastric cancer(GC)is one of the most common malignant tumor in our country,and its incidence is just less than the lung cancer.Because of lacking the significant symptoms,a part of GC patients were diagnosed in the advanced stage,leading to these patients losing their best treatment chance.MALAT1(Metastasis-associated lung adenocarcinoma transcript 1),as a kind of long non-coding RNA,many studies reveal that MALAT1 plays a vital role in the development of GC,and tissue MALAT1 levels were significantly higher in gastric cancer patients,In addition,high levels of plasma MALAT1 independently correlated to a poor prognosis for gastric cancer patients.The aims of this study is to explore the expression profile of MALAT1 in GC patients with more cases,and access the diagnostic value of MALAT1 in GC.Methods1.Quantitative Real-Time polymerase chain reaction(qRT-PCR)was used to detected the expression of MALAT1 in 96 paired of GC tissue and the para-tumor tissues,as well as plasma of the 239 GC patients,239 healthy controls,and 92 chronic atrophic gastritis patients.2.The chemiluminescent immunoassay Kits was used to detected the expression levels of CEA,PGI,PGII and other biochemistry index.3.The SPSS 21.0 statistics was used to analysis the data,and the students’T test was used to comparing the two groups of data.The MALAT1 relative expressing level is displayed as-△CT=-(MALAT1 CT value-GAPDH CT value)ROC curve was established to access the diagnostic value of MALAT1 in GC.Results1.The qPCR result revealed that the expression level of MALAT1 in the GC tissues(-5.43±0.11)is significantly higher than the para-tumor tissues(-6.79±0.14),which showed significant negative correlation with the differentiation degree,however,there is a significant positive correlation with the TNM stages of the patients.2.The expression level of MALAT1 in the GC plasma(-2.61 ±0.06)is significantly higher than that both in the healthy control plasma(-4.47±0.23,P<0.05)and the chronic atrophic gastritis patients(-4.22±0.28,P<0.05).I found that the expression level of MALAT1 in the GC plasma appears a significant negative correlation with the differentiation degree(P<0.01),but asignificant positive correlation was identified with both the tumor size(P=0.012)and TNM stages(P<0.01)of the patients.3.Furthermore,ROC curve shows that the plasma MALAT1 level is a good biomarker to diagnose GC from healthy controls and chronic atrophic gastritis patients(AUC=0.862,95%CI=0.791-0.896 and AUC=0.771,95%CI=0.683-0.837 respectively).Correspondingly,the sensitivity and specificity is 0.873,0.765 and 94.2%,71.2%,respectively.In addition,plasma MALAT1 is better on the sensitivity and specificity than the clinical common biomarker CEA(59.5%,53.7%)and PGⅠ/Ⅱ(69.6%,59.6%)in gastric cancer diagnosis.ConclusionsThe expression level of MALAT1 in the GC tissues is significantly higher than the para-tumor tissues,and the high expression level of MALAT1 was also found in the GC serum than that in the healthy control.Therefore,base on these investigation,MALAT1 may be a good biomarker for GC early diagnoseand treatment.