PAI-1 expression levels in gastric cancers are closely correlated to those in corresponding normal tissues.

Background/Aims: To investigate the mechanism of PAI-1 overexpression in gastric cancers, the PAI-1 expression levels in gastric cancers were compared to those in the corresponding normal tissues. Methodology: A quantitative RT-PCR for PAI-1 gene was performed in gastric cancers and corresponding normal tissues, and evaluated the association between the PAI-1 expression levels in gastric cancers and those in corresponding normal tissues. Results: There was a significant correlation between gastric cancer and corresponding normal PAI-1 expressions with a Spearman's rank correlation coefficient of 0.74 (p<0.0001). PAI-1 expression levels in corresponding normal tissues increased significantly with tumor stage [stage I, -8.04±0.72; stage II, -7.71±0.61; stage III, -6.81±0.51; stage IV, -4.95±0.20 (p=0.0022)). Conclusions: Previous studies found that PAI-1 overexpression was significantly associated with malignancy of gastric cancers. Taken together, PAI-1 overexpression in gastric cancers might be originated from higher PAI-1 expression in corresponding normal tissues and result in a malignant phenotype of these cancers.