MiR-21 expression changes in paraffin-embedded tissues of colorectal cancer

YAN Xiaoli; DU Mengnan; ZHENG Jining

doi:10.3969/j.issn.1002-266X.2017.10.004

Abstract：Objective To observe the expression changes of microRNA-21 (miR-21) in paraffin-embedded tissues of colorectal cancer,and to explore its clinical significance.Methods We extracted RNA from 40 cases of colorectal cancer samples and their corresponding cancer-adjacent normal tissues which were fixed by formalin and embedded by paraffin.MiR-21 expression was detected by reverse transcription quantitative real-time PCR,and we analyzed the relationship between the miR-21 expression and clinicopathologic features of colorectal cancer patients.Results The relative expression of miR-21 in the cancer tissues was-4.28±1.67,which was 4.69 times higher than that (-2.05±1.85) in the normal tissues adjacent to carcinoma (P＜0.05).There was no significant difference in the expression of miR-21 among patients with different sex,tumor shape and position (all P＞0.05).However,the level of miR-21 in patients with median age or higher,lymph node metastasis,low degree of differentiation and high infiltration depth of carcinoma was higher than that in patients with age lower than the median age,no lymph node metastasis,high degree of differentiation and low infiltration depth of carcinoma (all P＜0.05).Conclusions MiR-21 expression is increased in paraffin-embedded tissues of colorectal cancer,indicating miR-21 may be involved in the regulation of biological behaviors,such as the occurrence,development,differentiation and metastasis of colorectal cancer.Paraffin-embedded tissue may be an important resource for studying tumor microRNAs.