| Objective: Global cancer statistics report shows that colorectal cancer isone of the most common cancer. But,its pathogenesis is not fully clear. Thedevelopment of colorectal cancer is elated to a variety of factors. miRNA playan important role in cancer. miRNAs are down-regulated or up-regulated invarious cancer types, triggering abnormal cell differentiation, proliferation andapoptosis. To examine the expressions of microRNA-187*（miR-187*）andmicroRNA-451（miR-451）in colorectal carcinoma and normal mucosa usingby real time PCR and study the relationship between the expressions and theclinicopathological characteristics of patients. Then to observe the effect ofmiR-187*on proliferation and apoptosis of colon cell lines by colonyformation, MTT assay and FCM. To evaluate diagnosis value of miR-187*and miR-451for colorectal carcinoma as tumour marker, elucidate thebiological function of miR-187*in the development of tumor, providetheoretical basis for pathogenesis of colorectal carcinoma.Methods:140cases of fresh colorectal tissue specimens from Hebei MedicalUniversity Fourth Hospital and Hebei Medical University First Hospitalbetween May,2011and May,2012were collected, including colorectalcarcinoma and normal mucosa tissue.2Cell culture was performed for colon cell lines SW620，SW480，SW1116，HCT116，HT29，DLD1，LOVO和Caco-2.3miR-187*and miR-451expressions in colon cell lines were detected.Then compared their expressions in SW480and SW620.4The expressions of miR-187*and miR-451were examined incolorectal carcinoma and normal mucosa using by real time PCR, and studythe relationship between the expressions and the clinicopathological characteristics of patients.5miR-187*minic was transfected into colon cell lines HCT116andSW1116, paralleled with blank and control groups.6Colony formation assay were performed in blank, control andexperimental groups to analyze the effect of miR-187*on proliferation ofHCT116cell and SW1116cell.7MTT assay were performed in blank, control and experimental groups,OD value were detected respectively after12,24,36,48,60h of transfectionand then cell growth curve were drew.8Flow Cytometry were performed in blank, control and experimentalgroups to analyze the effect of miR-187*on apoptosis of HCT116cell.9All experimental data were analyzed by SPSS13.0statistical software.The results were measured by （meansstandard±deviations） or median（quartile）. Wilcoxon-test or t-test was used to analyze comparison of pairedsample, Mann-Whitney-test to analyze independent sample, two-Way ANOVAto analyze repeated measurement data. P<0.05was regarded as statisticalsignificance.Results:1The expressions of miR-187*and miR-451in colon cell linesSW620,SW480,SW1116,HT29,DLD1,LOVO and Caco-2were higher thanthat in normal mucosa tissue. But its expression was no differences between incolon cell lines SW620and SW480.2The expressions of miR-187*in colorectal carcinoma tissue andmatched normal mucosa tissue were0.165（0.106，0.428） and0.334（0.211，0.712） respectively. The miR-187*expression in colorectal carcinoma washigher than that in normal mucosa tissue, there were significant differences(P=0.041). The expressions of miR-451in colorectal carcinoma tissue andmatched normal mucosa tissue were0.218（0.106，0.542）and0.633（0.274，1.468） respectively. The miR-451expression in colorectal carcinoma washigher than that in normal mucosa tissue, there were significant differences（P<0.001）. 3The expressions of miR-451was correlated with pathological type andneoplasm location. The expression of miR-451was lower in poorlydifferentiated and Mucinous carcinoma CRC tissues. There were significantlydifferences (P=0.023,0.044). But its expression was not correlated with sex,age, lymph node metasis and clinical stage.(P>0.05).The expressions ofmiR-187*was correlated with pathological type and age. The expression ofmiR-187*in adenocarcinoma were higher than that in mucinous carcinoma.And its expression in older was lower than in younger. There weresignificantly differences (P=0.001,0.016). But its expression was notcorrelated with sex, neoplasm location, lymph node metasis and clinical stage.(P>0.05).4The number of cell colony did not show significant difference betweenblank group and control group in HCT116cell, but the cell colony number inexperimental group was higher than that in control group, there weresignificantly differences（P=0.036）. The number of cell colony did not showsignificant difference between blank group and control group in SW1116cell,but the cell colony number in experimental group was higher than that incontrol group, there were significantly differences（P=0.003）.5After12,24,36,48,60h of transfection, the OD value by MTT assaydid not show significant difference between blank group and control group inHCT116and SW1116cell lines; the OD value in experimental group werehigher than that in control group at every interval of12hours, there weresignificantly differences（P<0.0001）.6The apoptosis rate by Flow Cytometry did not show significantdifference between blank group and control group in HCT116cell; the earlyapoptosis rate in experimental group was higher than that in control group,there were significantly differences（P=0.024）, the late apoptosis rate did notshow significant difference.Conclusions:1The expressions of miR-187*and miR-451were at a low level incolorectal carcinoma. miR-187*and miR-451were potent tumor suppressor in colorectal carcinoma.2The expression of miR-451in CRC tissues was lower, especially inpoorly differentiated and Mucinous carcinoma CRC tissues. This result issuggest that it might help us to determine the degree of malignancy andprognosis of colorectal cancer.3The expression of miR-187*in Mucinous carcinoma CRC tissues waslower. This result show that it also might help us to determine the degree ofmalignancy and prognosis of colorectal cancer.4The expression of miR-187*in under age69was lower than in overage69. As growing up, the down regulation of MIR expressing lever haverelation to the increasing rates of colorectal carcinoma.5miR-187*through suppresses cell proliferation and induces apoptosisto play an important role as anti-oncogenes in the pathogenesis of colorectalcarcinoma. |
