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.