TDGF1 is a novel predictive marker for metachronous metastasis of colorectal cancer

Teratocarcinoma-derived growth factor 1 (TDGF1) is a member of the epidermal growth factor-cripto FRL1 cryptic protein family and is involved in the activation of several different signaling pathways during embryonic development and cellular transformation. Previous reports show that TDGF1 regulates the activation of several signaling pathways and controls cellular transformation in embryonic status, whereas its significance in colorectal cancer (CRC) is not yet fully understood. The present study comprised 55 patients who underwent surgery for CRC, as well as two cell lines derived from human CRC. The correlation of gene expression with clinical parameters in patients was assessed. The biological significance of TDGF1 expression was evaluated by knockdown experiments in the cell lines. Seventeen of 55 (30.9%) cases exhibited a higher TDGF1 expression in cancerous regions than in marginal non-cancerous regions. Patients with high TDGF1 expression were statistically susceptible to a recurrence of the disease, and showed poorer disease-free survival than those with low expression. The assessment of TDGF1 knock-down in the 2 cell lines demonstrated that the siRNA inhibition resulted in a statistically significant reduction in cell growth and invasion. In conclusion, the present data strongly suggest the usefulness of TDGF1 as a predictive marker for metachronous metastasis in CRC patients.