Correlation between expression of miR-155 in colon cancer and serum carcinoembryonic antigen level and its contribution to recurrence and metastasis forecast

OBJECTIVE: To analyze the correlation between expression of miR-155 in colon cancer tissue and serum carcinoembryonic antigen (CEA) levels, and then explore its contribution to forecasting recurrence and metastasis.

METHODS: Eighty-four pairs of colon cancer specimens and their corresponding non-tumor adjacent tissues were collected and analyzed between March 2009 and December 2011 in Xiangyang Central Hospital, Xiangyang, Hubei, China. The expression of miR-155 in both tissues was tested using reverse transcription-polymerase chain reaction (RT-PCR), the preoperative serum CEA level was assessed, and the postoperative serum CEA level was also assessed bimonthly during the follow-up period of 2 years.

RESULTS: The expression of miR-155 in colon cancer tissue was significantly higher than that in normal tissues (p<0.05), it had an obvious positive correlation with the preoperative serum CEA levels (p<0.01), and a negative correlation with time of duration since the serum CEA level increased again postoperatively (p<0.01). The expression of miR-155 in the recurrence and metastasis group was significantly higher (6.06+/-3.73 times) than that in the non-recurrence and non-metastasis group (p<0.05). An increase in the postoperative serum CEA levels was significantly correlated with recurrence and metastasis of the tumor postoperatively.

CONCLUSION: The expression of miR-155 is up-regulated in colon cancer tissue. A combination of miR-155 level assay in colon cancer tissue and the serum CEA level both pre- and postoperatively can afford more accurate information for diagnosis and prognosis, especially for predicting recurrence and metastasis postoperatively.