OBJECTIVETo detect plasma miR-106a level in patients with colorectal cancer (CRC) and analyze its correlation to the clinicopathological features and disease diagnosis.

METHODSmiRNA expression profiling was performed using miRNA microarray chip for 3 colorectal adenocarcinoma samples and matched normal tissues. Plasma samples was collected from 50 colorectal cancer patients for quantitative analysis of miR-106a using real-time RT-PCR using 47 plasma samples from healthy volunteer as the control. Forty plasma samples were collected from these patients 7 days after operation to examine the changes in miR-106a expression.

RESULTSmiR-106a was differentially expressed in colorectal adenocarcinoma compared to normal tissues. The plasma levels of miR-106a expression were significantly higher in the cancer patients than in the healthy control group (P=0.012). miR-106a expression significantly decreased after the operation compared with its preoperative level (P<0.01), and no correlation was found between preoperative plasma miR-106a and the clinicopathological features including lymph node metastasis and TNM stage (P>0.05). miR-106a showed a receiver operating characteristic (ROC) curve area of 66.1%, a sensitivity of 62.3%, and a specificity of 68.2% in discriminating colorectal cancer patients from the control subjects.

CONCLUSIONplasma miR-106a is up-regulated in CRC patients, suggesting its potential value for the diagnosis of CRC.