To investigate the expression of CUL4B and miR34a in rectal cancer and its relationship with clinicopathological parameters and prognosis.

From January 2013 to December 2015, 80 cases of rectal cancer tissues and adjacent normal tissues were collected from the Second People’ s Hospital of Hainan Province. The positive expression of CUL4B protein was detected by immunohistochemical SP method. The expression levels of CUL4B and miR34a mRNA in the patients’ tissues were detected by qPCR method, the correlation between the expression levels of CUL4B and miR34a and the relationship with the patients’ clinicopathological parameters were analyzed. Kaplan-Meier method was used to analyze the 5-year survival rate of patients.

The positive expression rate of CUL4B protein in rectal cancer tissue was 66.25%, which was significantly higher than 35.0% in adjacent tissues (P<0.05). The expression levels of CUL4B mRNA in adjacent tissues and rectal cancer tissues were (1.03±0.11) and (2.18±0.16) respectively, and the relative expression levels of miR34a were (1.95±0.08) and (0.89±0.19) respectively, with significant differences (P<0.05). The relative expression level of CUL4B in rectal cancer tissue was significantly negatively correlated with the relative expression level of miR34a. The expression of CUL4B was significantly correlated with the degree of differentiation, liver metastasis, and T stage (P<0.05), and the expression of miR34a was significantly correlated with the degree of differentiation, vascular infiltration, liver metastasis, and T stage (P<0.05). The 5-year survival rates of the CUL4Blow-expression group and the high-expression group were 76.5% and 54.3% respectively, and miR34a high-expression group and the low-expression group were 71.1% and 46.0% respectively, and the differences were statistically significant (P<0.05).

The expression level of CUL4B is up-regulated and the expression level of miR34a is down-regulated in rectal cancer tissues, and its expression level is negatively correlated. The expression levels of CUL4B and miR34a have a significant impact on the prognosis of patients with rectal cancer, and they are expected to become specific indicators for the evaluation of the prognosis of rectal cancer.