Objective: To investigate the features of expression of miRNAs in colon cancer and corresponding normal tissues and the significance thereof in the diagnosis of colon cancer.
Methods: Fifteen pair samples of colon cancer and matched adjacent normal tissue were collected during operation. A high-throughput real-time quantitative RT-PCR method designed to detect mature miRNA sequences was adapted to screen miRNA expression patterns in 6 pairs of matched colon cancer and normal adjacent tissue samples. Northern blotting was conducted to verify the accuracy of t he real-time qRT-PCR assay. Moreover, a thermostable reverse transcriptase based real-time qRT-PCR assay designed to quantify the miRNA precursors was performed. Problem analysis method was used to quantitatively determine the characteristics (cancer or non-cancer) of the other 9 pair samples.
Results: Among the more than 200 miRNAs examined, 132 were found to be expressed in both the colon cancer and normal adjacent tissue samples. Compared with normal tissue, 47 kinds of miRNA in cancer were down-regulated (less than 0.66). The results of qualitative determination on the 9 samples of cancer tissue/normal tissue were con-sistent with the results of pathological examination.
Conclusion: Closely linked with the pathogenesis and development of colon cancer, miRNA may be a promising diagnostic biomarker in diagnosis of colon cancer.