The Effect Of Mi R-17-92 Cluster On Cancer Screening And Cancer Prognosis And Its Potential Mechanisms

Objective:To identify diagnostic efficacy of the mi R-17-92 gene cluster as a marker of early cancer screening;to evaluate the effect of mi R-17-92 gene cluster expression in the blood and tissues of cancer patients on the prognosis of cancer;To explore the effect of mi R-19b on colorectal cancer cell function and possible molecular mechanisms.Methods:The research content is divided into three parts.Meta-analysis were used in the first and second parts to evaluate the overall diagnostic accuracy of mi R-17-92 gene cluster in early cancer screening and its role on the prognosis of cancer.We searchedliterature published before March 31th,2017 in PubMed,Embase,Cochrane and Web of Science databases.The search language is limited to English and only human studies were included in our analysis.An independent quality assessment by two observers was conducted using the Newcastle-Ottawa Quality Assessment Scale(NOS)to assure the quality of inclusion.A high quality study was classfied if the score equals to or greater than 7.A moderate study was classfied if the score ranged from 4 to 6.Studies with NOS scores less than 4 was considered with low quality and excluded from the analysis.The parameters used in the first part include first author,year of issue,country,ethnicity,mi R-17-92 gene cluster test sample type,detection method,sample sizes for cases and controls,cancer type,source of controls,mean ages for cases and controls,diagnostic indicators:area under the curve(AUC)and its 95%confidence intervals(CIs),threshold,sensitivity and specificity.The data used in the second part include:first author,publication year,country,mi R-17-92 gene cluster test sample type,detection method,sample size,average follow-up time,hazard ratios(HRs)of elevated mi RNAs for overall survival(OS),disease-free survival(DFS),and progression-free survival(PFS),as well as corresponding 95%CIs and p values.The meta analysis software used include:MetaDiSc 1.4,RevMan 5.2,and Stata12.0 software.The results are mainly displayed in the form of forest plot and funnel plot.In the third part,we mainly explored the possible molecular mechanisms of mi R-19b in colorectal cancer cells.Human CRC cell lines including HCT116,HT29,SW480 and RKO and normal colon mucosal epithelial cell(FHC)were used in our study.To assess the expression of mi R-19b in colorectal cancer cells,we performed quantitative reverse transcription PCR using mi R-19b-specific primers.And then the mi R-19b mimic,the mi R-19b inhibitor,and the mi R-19b negative controls were transfected in colorectal cancer cells.CCK-8 and Edu assays were performed to test whether mi R-19b abnormal expression can alter colorectal cancer cell proliferation.Wound healing assay were conducted to examine the effect of mi R-19b on HCT116 cell migration.Biology software(circRNABase)was used to explore all potential targets of mi R-19b.Results:A total of 23 studies were included in the meta-analysis for the first part of the research content.The types of cancer involved included:colorectal cancer(CRC),gastric cancer(GC),hepatocellular carcinoma(HCC),non-small cell cancer(NSCLC),bladder cancer,and other cancers(including breast cancer,pancreatic cancer,prostate cancer,malignant mesothelioma(MM).The pooled sensitivity,specificity,positive likehood ratio(PLR),and negative likehood ratio(NLR)were 0.76(95%CIs:0.72-0.76),0.77(95%CIs:0.75-0.79),3.32(95%CIs:2.69-4.11),and 0.32(95%CIs:0.26-0.38),respectively.The value of pooled diagnostic odds ratio(DOR)was 11.84(95%CIs:8.56-16.39),and the pooled AUC was 0.8425.26 studies were included in the second part of the research content.Among them,23 reported patient OS,10 investigated DFS,and 3 focused on PFS.For those reporting OS,DFS,and PFS all together in their studies,we analyzed each of them separately.The overall HRs showed that high expression level of mi R-17-92 family was a predictor of poor overall survival(OS):adjusted HRs = 1.71,95%CIs:1.39-2.11,p<0.00001,and poor disease-free survival(DFS):adjusted HRs = 2.29,95%CIs:1.41-3.72,p = 0.0008.However,no association between mi R-17-92 family expression and cancer progress-free survival(PFS)was found(adjusted PFS:HRs=1.49,95%CIs:0.95-2.34,p=0.09).In the third part,We discovered that the level of mi R-19b was up-regulated in all colorectal cancer cells(HCT116,SW480,HT29,RKO)compared with FHC,suggesting mi R-19b may function as an oncogene in colorectal cancer.HCT116 cells transfected with the mi R-19b over-expression vector(pri-mi R19b)exhibited indifference growth compared with the control cells.We then conducted a wound healing assay to expolore the potential mechanism of mi R-19b in colorectal cancer.We found that mi R-19b had no effect on cell migration of HCT116 cell.Our findings suggest that mi R-19b may have no effect in the malignant properties of human colorectal cancer.Results of Biology software(circRNABase)found that a variety of circRNA have mi R-19 binding sites,which may play a key role in regulating mi R-19b functions.Conclusion:mi R-17-92 cluster could serve as a potential diagnostic biomarker for human cancers.A high expression of mi R-17-92 gene cluster in cancer patient indicates a poor survival,mi R-19b may function as an oncogene in colorectal cancer.circRNAs plays a key role in regulating mi R-19b functions.