Abstract: Abstract:Objective  To detect the expression levels of MicroRNA-21 (miR-21) in the colon cancer tissue samples and the cancer-adjacent tissues,and to explorethe relationship between the clinicopathological features and the expression of miR-21.Methods Real-time florescence quantitative PCR（RT-qPCR） was used to detect the relative expression levels of miR-21 in 50 samples including the colon cancer tissue samples and the cancer-adjacent tissues；and the expression changes of miR-21 in two kinds of tissues were analyzed.The relationships between themiR-21 expression levels and the location,depth of invasion and lymph node metastasis of colon cancer were studied.Results The miR-21 relative expression level in colon cancer tissue samples was significantly higher than that in cancer-adjacent tissues(P<0.05);the miR-21 expression level in  right colon cancer tissues was obviously higher than that in left colon cancer tissues (P<0.05);the  miR-21 expression level in Ⅲ stage and Ⅳ stage colon cancer tissues was  obviously higher than  that in Ⅰ stage and Ⅱ stage colon cancer tissues(P< 0.05);the expression levels of MiR - 21 in colon cancer with different depths of invasion had no statistically significant differences(P>0.05);the expression level of miR-21 in  colon cancer tissues with lymph node metastasis was  significantly higher than that in colon cancer tissues without lymph node metastasis (P>0.05).Conclusion The miR-21 expression level is increased  significantlyin colon cancer tissues compared with  cancer-adjacent tissues,and it is  related to the location,the clinical stage and the lymphy node metastasis of colon cancer.

Key words: microRNAs, colon neoplasms, polymerase chain reaction