[Expression of microRNA-29b in colorectal cancer and its relationship with clinicopathological features].

OBJECTIVE: The aim of this study was to detect the expression level of miR-29b in colorectal cancer (CRC) tissues and to analyze its relationship with clinicopathological features and prognosis. METHODS: The expression of miR-29b was detected by real-time quantitative PCR in 202 colorectal cancer tissues and adjacent colorectal tissues. Statistical analysis of the results was conducted using SPSS 16.0 software. RESULTS: The expression of miR-29b in colorectal cancer tissues and adjacent colorectal tissues was -7.761±0.115 and -7.150±0.137, respectively, with a significant difference between the two groups (P<0.01). Comparing colorectal cancer tissues with lymph node metastasis with those without lymph node metastasis, the expression of miR-29b (-7.528±0.158 vs. -7.988±0.164) was significantly increased (P<0.05). In addition, the expression of miR-29b in CRC according to TNM stage was -8.096±0.157 in stage Ⅰ/Ⅱ, -7.592±0.165 in stage Ⅲ and -6.603±0.468 in stage Ⅳ patients, showing a gradual increase depending on clinical staging (P<0.05). Univariate Cox regression analysis indicated that lymph node metastasis, differentiation degree and TNM stage were significantly related to the postoperative survival of colorectal cancer patients (P<0.001). Multivariate Cox regression analysis indicated that differentiation degree and TNM stage were independent factors impacting the survival of colorectal cancer patients (P<0.001). CONCLUSIONS: The expression level of miR-29b is reduced in colorectal cancer tissues compared with that in the adjacent colorectal tissues. High expression level of miR-29b is associated with lymph node metastasis and TNM stage of CRC. miR-29b may be a potential marker indicating colorectal cancer metastasis and malignant progression.