Study On Expression And Clinical Significance Of MicroRNA-200 Family In Gastric Cancer Serum

Objective:The serum levels of miR-200 family(including miR-200a,miR-200 b,miR-200c,miR-141,miR-429,such 5 sub group)were measured by RT-PCR in serum of patients with gastric cancer,the serum of healthy individuals,the serum of patients with gastric cancer tumor before resection and the serum of patients with gastric cancer tumor after resection.1?To investigate the differences in the expression of miR-200 family(miR-200 a,miR-200 b,miR-200c,miR-141,miR-429)in the serum of healthy and gastric cancer patients;2?To investigate the differences in the expression of each member of the family miR-200 in postoperative patients with gastric cancer and postoperative patients with gastric cancer;3?To screen out the target genes in the five members of the miR-200 family(this mi RNAs were differentially expressed in both healthy with gastric cancer patients and preoperative with postoperative sera),and then performed a large sample experiment;4?According to the results of the test target serum miRNA of healthy people and patients with gastric cancer,to investigate the sensitivity and specificity in diagnosis of gastric cancer,and to compare with traditional serum markers of gastric cancer like CEA,CA-199 and CA-724;According to the test results of the target miRNA in patients with gastric cancer before and after operation.to investigate the potential clinical value for evaluating the effect of surgical treatment.Method:Blood samples and their RNA from 32 patients with gastric cancer and 31 healthy volunteers were collected from Lanzhou General Hospital of Lanzhou Military Region.Clinical data were obtained by retrospective analysis of the medical records.Screening:Used the RT-PCR to detect the expression of the family of miR-200(miR-200 a,miR-200 b,miR-200c,miR-141,miR-429)in 11 healthy volunteers and 12 patients with gastric cancer serum and the serum of 12 patients with gastric cancer before and after operation,and to explore the differences in the expression of each member.Screening out the miRNAs which were differentially expressed in serum of healthy people with patients with gastric cancer and the patients with gastric cancer before and after operation.Validated:To validate the selected target miRNA in the next step;Extracted serum from the other 20 cases of healthy people and 20 patients with gastric cancer before and after operation.And combined with the expression of target miRNA of the early 11 healthy persons and the early12 patients with gastric cancer.Completed the experiment to detect the expression of target miRNA in serum of 31 healthy persons and 32 patients with gastric cancer preoperative andpostoperative.Clinical significance:(1)Analysis of expression of miRNA in gastric cancer target in serum by using independent sample t test;(2)The relationship of the expression of miR-200 family members between with the age,gender,tumor differentiation,lymph node metastasis,TNM staging and clinical pathological features was analyzed by chi-square test or t-test.;(3)The diagnostic value of serum target miRNA levels in patients with gastric cancer was assessed by using the receiver operating characteristic curve(ROC)and the area Under Curve(AUC),and were compared with tumor markers CEA,CA-199,CA-724;(4)The difference of mi RNA expression between preoperative and postoperative patients was analyzed by paired t test,to evaluate the potential clinical value for evaluating the effect of surgical treatment.Result:1?The early screening results showed,5 members of the mirna-200 family,miR-200 b and miR-200c were differentially expressed in the serum of healthy people and patients with gastric cancer(P<0.05),and the expression level of miR-200c is relatively lower than mi R-200 b,No statistically significant differences in the level of miR-200a?miR-141?mi R-429(P>0.05).At the same time,between before operation and after operation,the serum expression level of miR-200c in patients with gastric cancer was different(P<0.05),miR-200a?miR-200b?miR-141?miR-429 were no statistically significant differences(P>0.05)?MiR-200c(which was different expression in healthy and gastric cancer patients serum,gastric cancer patients before and after surgery)as the target gene for further validation analysis;2?The validated results show that the expression of miR-200c in gastric cancer patients was significantly lower than that in patients with gastric cancer(P<0.05).The expression of miR-200c in postoperative gastric cancer patients was significantly higher than that in preoperative(P<0.05).The results are consistent with the previous screening results.Logistic regression analysis showed that serum miR-200c level was an independent risk factor for gastric cancer and was negatively correlated with the occurrence of gastric cancer;3?Compared with 31 normal control group,the expression of miR-200c was down-regulated in the serum of patients with early gastric cancer(stage I / II),the difference was statistically significant(P<0.05).The abnormal expression of miR-200c was associated with the clinical stage and the number of lymph node metastases.The later the stage,the more lymphatic metastasis,and the lower the expression of mi R-200c(P<0.05);However,the miR-200c in gastric cancer patients was not statistically significant correlate with gender,age,depth of invasion,degree of differentiation and tumor location(P> 0.05);4?The area under the curve of serum mir-200c(0.775)greater than CEA(0.646)?CA-199(0.649)and CA-724(0.660);Compared with CEA,CA-199 and CA-724,the serum miR-200c in the diagnosis sensibility of gastric cancer,were respectively 78.1%?34.4%?31.3%?40.6%(P<0.05).The value of serum miR-200c in the diagnosis of gastric cancer was significantly higher than that of CEA,CA-199 and CA-724.Conclusion:1 ?miR-200c is down-regulated in serum of patients with gastric cancer.The abnormal expression of miR-200c is related to the TNM staging of gastric cancer patients and the number of lymph node metastasis in gastric cancer patients,suggesting that it may be as a tumor suppressor gene to involve in the development and progression of gastric cancer;2 ?miR-200c as a gastric cancer marker which has a high sensitivity and specificity.The serum miR-200c has certain clinical value in the diagnosis and evaluation of surgical results in gastric cancer,may become a new clinical marker for gastric cancer.