The potential role of microRNA-31 expression in early colorectal cancer

The expression of microRNA-31 (miR-31) has been implicated in the progression of some human malignancies including colorectal cancer. However, the clinical significance of the expression of miR-31 in submucosally invasive (T1) colorectal cancer remains unclear. The aim of the present study was to delineate the relationship between clinicopathological features and the oncogenic modulator miR-31 in submucosally invasive colorectal cancer. We investigated the expression of miR-31 in 50 submucosally invasive colorectal cancer specimens, along with the corresponding non-tumoral mucosa specimens, using a real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The relationships between miR-31 expression levels and clinicopathological characteristics were assessed. The miR-31 host gene locus was investigated using fluorescence in situ hybridization. qRT-PCR revealed that the expression of miR-31 was higher in colorectal cancer tissue than in non-tumoral tissue (P = 0.0002). The up-regulated expression of miR-31 may play an oncogenic role in the early stage of carcinogenesis in colorectal cancers.