Evaluating the amount of miR-135b and miR-221 in plasma and stool of patients with colorectal cancer

Abstract

Colorectal cancer is one of the most common cancers worldwide and it is the third most prevalent cancer among other cancers. Micro RNAs, as a member of the messenger pathways involved in cell cycle regulation and apoptosis, play a key and important role in the carcinogenesis process of various types of malignancies. miR-135b and miR-221 are two transcription factors that have been confirmed to play a role in colorectal cancer in previous studies. Therefore, in the present study, changes in the relative expression of these genes during carcinogenesis were analyzed and the relationship between relative expression of these genes and the clinicopathological information of the patients was investigated. Methods: A series of 40 serum and fecal samples from 40 patients and 40 matched healthy controls were collected during the identification and surgical procedure of colorectal cancer patients. After extraction of total RNA, Real-time PCR method was used to measure expression changes of target genes. Differences in mRNA expression level of these genes as well as their association with clinicopathologic features of patients were evaluated by appropriate statistical tests. P value <0.05 was considered significant. Results: The relative expression level of both genes was significantly increased in serum samples of patients compared to healthy individuals (Pvalue = 0.005). But the relative expression levels of the genes in the fecal samples of the patients were not significantly different in the confidence interval. There was no significant relationship between changes in gene expression (Pval0.05).