Plasminogen activator inhibitor-1 (PAI-1) 4 G/5 G polymorphism and endometrial cancer. Influence of PAI-1 polymorphism on tissue PAI-1 antigen and mRNA expression and tumor severity.

Plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism may have significance for PAI-1 expression. High levels of PAI-1 in endometrial cancer patients are associated with a poor prognosis. The objective of this study was to evaluate the PAI-1 4G/5G polymorphism in women with and without endometrial cancer and to analyze the influence of this polymorphism on PAI-1 expression in endometrial tissue. In 423 women (212 patients with endometrial cancer and 211 controls) PAI-1 4G/5G polymorphism was determined by PCR amplification using allele-specific primers. Quantitative real-time RT-PCR assay was used to quantify PAI-1 mRNA and PAI-1 protein levels were quantified by ELISA in tissue extracts from 33 patients with endometrial cancer and from 70 endometrial tissues from control women. The frequency of PAI-1 4G/4G genotype (P=0.010) and the PAI-1 4G allele (P=0.009) was significantly higher in patients than in controls. The frequency of PAI-1 4G allele was significantly higher in patients with stage IB than in those with stage IA (P=0.03). Control women with the 4G/4G genotype had higher endometrial PAI-1 protein (P=0.018) and mRNA (P=0.004) levels than those with the 5G/5G genotype. A significant increase in PAI-1 protein and mRNA was observed in endometrial cancer tissue in comparison with the endometrial tissue from control women (P<0.01). In conclusion, frequencies of the PAI-1 4G allele and 4G/4G genotype were found significantly more often in women with endometrial cancer than in controls. PAI-1 levels in endometrial tissue seem to be associated with PAI-1 4G/5G polymorphism. These findings suggest that the PAI-1 4G/4G genotype may be associated with the risk of endometrial cancer in a Caucasian population. Further studies with a larger number of patients are needed to clarify the influence of this PAI-1 polymorphism in endometrial cancer.