Expression status of S100A14 and S100A4 correlates with metastatic potential and clinical outcome in colorectal cancer after surgery

To investigate whether S100A14 and S100A4 expression correlates with metastatic potential and prognosis in colorectal cancer (CRC), we firstly used RT-PCR analysis to detect mRNA expression of S100A14 and S100A4 in 40 pairs of fresh tumor samples matched with adjacent normal tissues. We then evaluated the clinical significance of our findings with immunohistochemistry on 115 samples of formalin-fixed and paraffin-embedded tumors on tissue microarrays. Typically, we identified decreased S100A14 mRNA levels (52.5%, 21/40), and increased S100A4 mRNA levels (70.0%, 28/40) in primary CRC samples. In addition, down-regulated or absent S100A14 expression was detected in 56.5% of samples (65/115) and was correlated with poor differentiation (P=0.010). In contrast, overexpressed S100A4 was detected in 57.4% of samples (66/115) and was associated with lymph node metastasis (P=0.001). Simultaneous S100A14 low-expression and S100A4 high-expression was correlated with high CRC metastatic potential (P<0.001). Taken together, the signature derived from the combined expression status of S100A14 and S100A4 could be a valuable prognostic indicator in CRC.