Study On Molecular Biomarkers Of Early Detection And Prognosis For Patients With Colorectal Cancer

Part 1 Screening and Validation of Serum miRNAs as Biomarkers for Early Detection of patients with Colorectal Cancer[Objective]The study aimed to screen microRNAs(miRNAs)that can be used for the early detection of colorectal cancer(CRC)based on differential expression of miRNA in serum.[Methods]A three-stage study was designed with a total of 217 CRCs,168 colorectal adenomas(CRAs),and 190 healthy controls(HCs).A quantitative reverse transcription polymerase chain reaction was performed in three stages.We screened 528 miRNA expression profiles in the sera of 40 patients(CRC n=20,CRA n=10,and HC n=10)for candidate miRNAs,then 210 serum samples(CRC n=90,CRA n=60,and HC n=60)were used for screening of candidate miRNAs.Three hundred and twenty-five independent individual samples(CRC n=107,CRA n=98,and HC n=120)were used to validate the most differentially-expressed miRNAs in the screening stage,and binary logistic regression was used in the validation stage.A receiver operating characteristic curve was drawn to evaluate the diagnostic accuracy.[Results]A 5-serum miRNA panel(miRNA-1246,miRNA-202-3p,miRNA-21-3p,miRNA-1229-3p,and miRNA-532-3p)effectively distinguished CRCs from HCs with 91.6%sensitivity and 91.7%specificity.The area under the curve(AUC)was 0.960(95%confidence interval[CI]:0.937-0.983).In addition,the panel also accurately distinguished CRCs from CRAs with 94.4%sensitivity and 84.7%specificity.The AUC was 0.951(95%CI:0.922-0.980).[Conclusion]Our 5-serum miRNA panel accurately distinguished CRCs from CRAs and HCs with high sensitivity and specificity.The 5-serum miRNA panel may be a promising prospect for application as a nonintrusive and inexpensive method for the early detection of CRC.Part 2 Screening and validation the prognostic value of miRNA in tissue for patients with stage II and III colorectal cancer[Objective]The study aimed to screen and validate differential expression microRNAs(miRNAs)in colorectal cancer tissues,and to evaluate their prognostic value.[Methods]A total of 200 patitents with colorectal cancer were enrolled,and we obtained formalin-fixed paraffin-embedded tumor samples from these patients.According to the follow-up results,patients were divided into a good prognosis group and a poor prognosis group.In primary screening stage,we screened 462 miRNA expression profiles in the samples of 20 patients(good prognosis group,n=10,poor prognosis group,n=10)for candidate miRNAs,then 40 patients' samples(good prognosis group,n=30,poor prognosis group,n=30)were used for screening of candidate miRNAs,120 independent samples(good prognosis group,n=60,poor prognosis group,n=60)were used to validate the most differentially-expressed miRNAs in the screening stage,logistic binary regression analysis was performed basing on miRNA expression levels.A receiver operating characteristic curve was drawn to evaluate the prognostic value of miRNA alone or in combination.[Results]A panel of four-miRNA(miR-221-5p,miR-339-5p,miR-18a-3p and miR-92a-3p)in tissue can effectively distinguished good prognosis CRCs from poor prognosis CRCs with 76.7%sensitivity and 85.0%specificity The area under the ROC curve was 0.793(95%confidence interval[CI]:0.706-0.880).[Conclusion]The four-miRNA panel can effectively distinguished good prognosis CRCs from poor prognosis CRCs with high sensitivity and specificity.Part 3 The blood mSEPT9 is capable of assessing the surgicaltherapeutic effect and the prognosis of colorectal cancer[Objective]To investigate the performance of methylated SEPT9(mSEPT9)in assessing the surgical therapeutic effect and prognosis of colorectal cancer(CRC).[Methods]Blood samples before surgery and 1 and 7 days after surgery were obtained from 120 CRC patients,and mSEPT9 and carcinoembryonic antigen(CEA)assays were performed.[Results]The mean plasma mSEPT9 level showed 57.6-times and 131.1-times decrease 1 day and 7 days after surgery,respectively.In contrast,mean CEA levels showed 2.51-and 2.70-times decrease 1 and 7 days after surgery.86.7%of patients can be assessed by mSEPT9 while 44.2%can be assessed by CEA.Positive mSEPT9 detection before surgery correlated with higher risk of death aftersurgery.[Conclusion]mSEPT9 is effective for CRC postsurgical assessment and prognosis prediction.