Background: There are increasing data about microRNAs (miRNA) in the literature, providing abundant evidence that they play important roles in pathogenesis and development of colorectal cancer. In this study, we aimed to investigate the miRNA expression profiles in surgically resected specimens of patients with recurrent and non-recurrent colorectal cancer.
Materials and methods: The study population included 40 patients with stage II colorectal cancer (20 patients with recurrent tumors, and 20 sex and age matched patients without recurrence), who underwent curative colectomy between 2004 and 2011 without adjuvant therapy. Expression of 16 miRNAs (miRNA-9, 21, 30d, 31, 106a, 127, 133a, 133b, 135b, 143, 145, 155, 182, 200a, 200c, 362) was verified by quantitative real-time polymerase chain reaction (qRT-PCR) in all resected colon cancer tissue samples and in corresponding normal colonic tissues. Data analyses were carried out using SPSS 15 software. Values were statistically significantly changed in 40 cancer tissues when compared to the corresponding 40 normal colonic tissues (p<0.001). MiR-30d, miR-133a, miR-143, miR-145 and miR-362 expression was statistically significantly downregulated in 40 resected colorectal cancer tissue samples (p<0.001). When we compared subgroups, miRNA expression profiles of 20 recurrent cancer tissues were similar to all 40 cancer tissues. However in 20 non-recurrent cancer tissues, miR-133a expression was not significantly downregulated, moreover miR-133b expression was significantly upregulated (p<0.05).
Conclusions: Our study revealed dysregulation of expression of ten miRNAs in Turkish colon cancer patients. These miRNAs may be used as potential biomarkers for early detection, screening and surveillance of colorectal cancer, with functional effects on tumor cell behavior.