PAI-1 (Plasminogen activator inhibitor-1) expression levels in colorectal cancers and corresponding normal tissues

10094 Background: We performed a quantitative RT-PCR for Plasminogen Activator Inhibitor-1 (PAI-1) gene in 55 surgical specimens of colorectal cancer (CRC) and corresponding normal mucosa. To test the hypothesis that PAI-1 may serve as a candidate marker for the malignant potential of CRC, we evaluated the possible relationship between PAI-1 gene expression levels and clinicopathological findings in CRC. Next, to investigate the mechanism of PAI-1 overexpression in CRC, we compared the PAI-1 expression levels in these cancers with those in the corresponding normal tissues. Results: A significant increase in PAI-1 expression scores was observed in node-positive CRCs (2.19Å}0.43) compared to negative ones (0.35Å}0.42) (P=0.0037) as well as in CRCs with distant metastasis (3.50Å}1.18) compared to negative ones (0.99Å}0.30). A significant increase in PAI-1 expression scores was observed in lymph node metastasis-positive CRCs (2.19Å}0.43) compared to negative ones (0.35Å}0.42) (P=0.0037) as well as in distant metastasis-positive CRCs (3.50Å}1.18) compared to negative ones (0.99Å}0.30). The PAI-1 expression score markedly increased with the tumor stage (P=0.0063; ANOVA test). Moreover, multivariate analysis revealed the PAI-1 expression score to be a strong and independent prognostic factor for CRC (P=0.0432). There was a significant correlation between CRC and corresponding normal PAI-1 expressions with a Spearman’s rank correlation coefficient of 0.81 (P < 0.0001). Conclusion: These results suggested that PAI-1 might serve as a new parameter for the prediction of prognoses in CRC. Taken together, PAI-1 overexpression in CRCs might originate from higher PAI-1 expression in the corresponding normal tissues and result in a malignant phenotype of these cancers. No significant financial relationships to disclose.