Objective: To investigate the binding activity of activator protein-1 (AP-1) with DNA probe in the colorectal carcinoma (CRC) tissues and surrounding tissues and explore the correlation between the activation of AP-1 signal transduction pathway and metastasis of CRC.
Methods: The AP-1 DNA binding activities were investigated by electrophoretic mobility shift assay (EMSA) in CRC specimens (T), surrounding tissues including 2 cm (P(2)), 5 cm(P(5)) far away from primary tumor margin and distal resection margin of the specimens (N). The mRNA expression level of vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9) were measured by quantitive reverse transcription polymerase chain reaction (Q- RT-PCR).
Results: The AP-1 DNA binding activity in T was significantly higher than those in P(2), P(5) and N (P< 0.05) tissues. There were significantly positive correlations between AP-1 DNA binding activity in tumor and invasive degree, lymphatic metastasis respectively (P< 0.01), but no correlation with histological classification and differentiation (P> 0.05). The transcription levels of VEGF and MMP-9 in CRC were significantly higher than those in P(5) and N (P< 0.01, P< 0.05) tissues. The transcription levels of VEGF and MMP-9 were significantly correlated with increasing AP-1 DNA binding activity (P< 0.01).
Conclusions: AP-1 is significantly correlated to the invasion and metastasis in CRC. The activation of AP-1 signal transduction pathway might be involved in the angiogenesis and of degradation extracellular matrix during tumor metastasis.