Clinical Study Of The Expression Change Of Serum MicroRNA In Colon Cancer

Part Ⅰ Preliminary screening of serum differentially expressed miRNAs in colon cancer patientsObjective:To screen differentially expressed miRNAs in serum of patients with colon cancer by microarray.Methods:The expression of miRNAs in serum samples of 3 patients with colon cancer and 3 healthy controls were detected by using miRNA UniTag^TMmicroarray chip developed by Suzhou Institute of Nanotechnology and Nanobionics,Chinese Academy of Sciences.The differentially expressed miRNAs in serum of colon cancer were analyzed.Results:The results of miRNA UniTagTM microarray chip hybridization showed that the differentially expressed miRNAs were screened from the serum of patients with colon cancer according to the change multipl≥ 1.5 and P value<0.05.There were 87 serum miRNAs differentially expressed in patients with colon cancer,of which 39 were up-regulated and 48 were down-regulated.Conclusions:Differential expression of miRNAs in serum of patients with colon cancer are successfully screened.Part Ⅱ Preliminary evaluation of the diagnostic efficacy and prognosis of serum miRNA expression profile in colon cancerObjective:To preliminary discussion the role of serum microRNA expression profile in the diagnosis and prognosis of colon cancer.Methods:（1）Real-time PCR was used to further validate the differ-rentially expressed miRNAs in microarray chip（top 5 expression changes in expression）by the training set（40 patients with colon cancer vs.40 normal controls）and validation set（60 patients with colon cancer vs.60 normal controls）,and the serum miRNA expression profile was constructed.（2）To evaluate the diagnostic value of serum miRNA expression profile in colon cancer.To analyze the expression changes of miRNA profile under different pathological parameters in colon cancer patients.To observe the expression changes of serum miRNA profile in colon cancer before and after operation.（3）Drawing survival curve and preliminarily studying the role of serum miRNA expression profile in predicting the prognosis of colon cancer.Results:（1）Real-time PCR was used to validate the differentially expressed miRNAs（the top 5 expression changes in microarray chip）in the training set and validation set.The results showed that the changes of serum expression of five miRNA（miR-31,miR141-5p,miR-224-3p,mR-576-5p and miR-4669）were most significantly different from those of the normal control group（P<0.05）.The expression of miR-31,miR-141-5p,miR-224-3p and miR-576-5p increased in the serum of colon cancer,while the expression of miR-4669 decreased in the serum of colon cancer.（2）These five miRNA had the ability to differentiate colon cancer patients from normal people.The combined expression profile of five miRNA was more effective than single miRNA in the diagnosis of colon cancer.With the decrease of differentiation degree of colon cancer,the expression of miR-31,miR-141-5p,miR-224-3p and miR-576-5p increased.The expression of miR-31,miR-141-5p,miR-224-3p and miR-576-5p increased with the progress of TNM stage in colon cancer,while the expression of miR-4669 was the opposite.The expression of miR-31,miR-141-5p,miR-224-3p and miR-576-5p increased in lymph node metastasis group,while the expression of miR-4669 decreased in lymph node metastasis group.The serum levels of miR-31,miR-141-5p,miR-224-3p and miR-576-5p decreased significantly after resection of colon cancer lesions.（3）When the expression of miR-31,miR-141-5p,miR-224-3p and miR-576-5p was higher than the cut-off value,the survival time of colon cancer was shorter,and when the expression of miR-4669 was lower than the cut-off value,the survival time of colon cancer was shorter.Conclusions:Serum miRNA expression profile has good diagnostic efficacy for colon cancer and is related to the prognosis of patients with colon cancer.Serum miRNA expression profile is expected to be a potential tumor marker for the diagnosis and prognosis of colon cancer.Part Ⅲ Bioinformatics analysis of serum miRNA expression profile in colon cancerObjective:To provide a basis for studying the molecular mechanism of serum miRNAs in the occurrence and development of colon cancer by bioinformatics analysis.Methods:Bioinformatics analysis of serum miRNA expression profile in colon cancer was performed using three databases（miRanda,Targetscan,miRdb）.The target genes of five target miRNA（miR-31,miR-141-5p,miR-224-3p,miR-576-5p,miR-4669）were predicted.GO-Analysis function analysis and Pathway-Analysis signaling pathway analysis were carried out for the obtained cross-target genes.Results:（1）TargetScan,Mianda and Midb database predicted that the number of cross-target genes in serum miRNA expression profile were 1997.（2）The significant function of cross-target gene of serum miRNAs expression profile GO-Analysis is closely related to ubiquitin-proteasome system.KEGGPathway signaling pathway analysis was significantly enriched in MAPK signaling pathway,Ubiquitin mediated proteolysis and ErbB signaling pathway.Conclusions:Bioinformatics analysis shows that serum miRNA profile and its target genes are involved in the regulation of the occurrence and development of colon cancer,and may play an important role in the occurrence and development of colon cancer.