In a previous study, we demonstrated that deficiency of microRNA-449a (miR-449a) promoted colorectal tumorigenesis. In this study, the significance of miR-449a in the prognosis and relationship with HDAC1 in colorectal cancer was examined.

Seventy-two patients with colorectal cancer and 16 patients with colorectal liver metastasis who underwent surgery were included. miR-449a expression in tumor tissue of resected specimen was investigated by real-time polymerase chain reaction and histone deacetylase 1 (HDAC1) expression was examined by immunohistochemistry.

Lymphovascular invasion and increased serum carcinoembryonic antigen levels were seen more frequent in patients with low miR-449a expression. Patients with low miR-449a expression were found to have a poorer prognosis than those with high expression. Vascular invasion, increased serum carbohydrate antigen 19-9 level and low miR-449a were associated with poorer disease-free survival. miR-449a expression was lower in metastatic liver tumor compared to primary tumor. HDAC1 positivity was higher in patients with low miR-449a.

miR-449a level might be a prognostic indicator for colorectal cancer and miR-449a might regulate HDAC1 expression.