High expression of microRNA‑31 and its host gene LOC554202 predict favorable outcomes in patients with colorectal cancer treated with oxaliplatin

The expression levels of microRNA‑31 (miR‑31) and LOC554202 have been previously investigated in colorectal cancer (CRC) and their oncogenic and/or tumor suppressive roles have been described. The aim of the present study was to examine the role of miR‑31 and its host gene LOC554202 in the prognosis of patients with CRC. Patients with CRC treated with oxaliplatin‑based chemotherapy between June 2005 and March 2010 were recruited to the First Affiliated Hospital of China Medical University. Tumor and adjacent mucosal tissues were collected. The detection of miR‑31 and/or LOC554202 was performed with probe hybridization targeting. Correlation analysis was performed among the expression levels of miR‑31, LOC554202, and their association with clinicopathological parameters and/or survival rates. miR‑31 and LOC554202 were expressed at high levels in CRC (P<0.01) compared with adjacent intestinal mucosa. A linear correlation was noted for the two markers in CRC tissues (P<0.01). The expression of miR‑31 was significantly higher in adenocarcinoma than in the adjacent intestinal mucosa (P<0.01), whereas the expression of LOC554202 was significantly higher in the adenocarcinoma and the rectal cancer tissue regions (P<0.01). The high expression levels of miR‑31 and LOC554202 were associated with high disease‑free survival (DFS) and overall survival (OS) rates (P<0.05). Associations between the increase in DFS and OS and the elevated expression levels of miR‑31 and LOC554202 were present in patients with colon cancer but not in patients with rectal cancer (P<0.05). These data indicated that miR‑31 and LOC554202 may be potential markers for evaluation of the prognosis of patients treated with oxaliplatin‑based chemotherapy.