Expressions Of MiR-21and Fluoropyrimidine Chemosensitivity Study In Colon Cancer

Background： Currently,Colon cancer is the higher malignanttumors.Early diagnosis and treatment is an effective way to improve thesurvival of Colon cancer patients.During the chemotherapy,colon tumorcell resistance to chemotherapeutic drugs is the main reason for treatmentfailure.Looking for a sensitive target for early diagnosis and individualizedtreatment,we get attention to MicroRNA-21(miR-21) from genemolecular level in malignant tumors.miRNAs are non-coding RNAs Invivo.The role of mir-21including regulation of organ formation,cellproliferation and apoptosis,tumor formation and so on.miR-21sensitivityto anticancer drugs.Thus,we speculate that miR-21can be used as apredictor of colon cancer early diagnostic markers and efficacy ofchemotherapy.Objective: To detect the expression levels of miR-21in the coloncancer tissue samples and the cancer-adjacent tissues,and to explore therelationship between the clinicopathological features and the expressionof miR-21.To investigate whether miR-21can be used as a biomarker forthe early detection of colon cancer and to explore its association withclinicopathologic features and sensitivity to fluoropyrimidine-basedchemotherapy.Methods:1.50samples including the colon cancer tissue samples and thecancer-adjacent tissues were collected between March2011and June 2012from the departments of Surgery.50cases colon cancer patientsconfirmed by pathology from our department,collect the blood samples ofthem.13patients with advanced colon cancer patients selected from the50patients was enrolled,application of fluorouracil drug for6cycles ofchemotherapy,collect the blood samples of pre-chemotherapy andpost-chemotherapy.The blood samples of20matched healthy volunteersas a control group were collected.2.We used real-time quantitative RT-PCR to investigate theexpression of miR-21in the plasma of CRC patients and healthy controls.3.We used real-time quantitative RT-PCR to investigate theexpression of miR-21in50samples including the colon cancer tissuesamples and the cancer-adjacent tissues.4.We used real-time quantitative RT-PCR to investigate theexpression of miR-21in the fluoropyrimidine of13post-chemotherapysamples compared with the levels in pre-chemotherapy samples.5.We used real-time quantitative RT-PCR to compared plasmamiR-21between(CR+PR)(n=11)samples and(PD+SD)(n=24) sampleswith fluoropyrimidine chemotherapy.Result:1.Analysis indicated that the CRC patients had significant higherlevels of miR-21in their plasma than in the healthy controls(P<0.0001).2.The miR-21relative expression level in colon cancer tissuesamples was significantly higher than that in cancer-adjacenttissues(P<0.05).3.The miR-21expression level of right colon cancer tissues isobviously higher than that of the left colon cancer tissue(P<0.05).4.The miR-21expression level of Ⅲ period and Ⅳ period coloncancer tissues obviously higher than that of Ⅰperiod and Ⅱ period colon cancer(P<0.05).5.The expression level of miR-21in colon cancer with differentdepth of invasion was not statistically significant(P>0.05).6.The expression level of miR-21in lymph node metastasis coloncancer tissue significantly higher than those without lymph nodemetastasis(P<0.05).7.MiR-21levels were significantly reduced in13post-chemotherapysamples compared with the levels in pre-chemotherapysamples(P=0.0438).8.The miR-21expression levels in the（PD+SD) roup than in the(CR+PR) group with Fluoropyrimidine chemotherapy, the difference wasnot statistically significant（P＞0.05）.Conclusion：1.The miR-21expression level is higher significantly in colon cancertissues than cancer-adjacent tissues,and it is also related to thelocation,the clinical stage and the lymphy node metastasis of colon cancercase.2.The plasma of miR-21levels of colon cancer patients wasdecreased after fluoropyrimidine chemotherapy.3.Different efficacy of patients has different miR-21expressionlevels after fluoropyrimidine chemotherapy.