Expression of Pin1 mRNA in non-small-cell lung cancer patients

Phosphorylation of proteins on serine or threonine residues preceding proline is a major regulatory mechanism in cell proliferation and transformation, which is catalyzed specifically by Pin1, a peptidylprolyl isomerase. Pin1 is overexpressed in several human cancers. The expression of Pin1 mRNA in the circulation was assessed in 26 patients with non-small-cell lung cancer who underwent surgical resection. They were randomly assigned to a pulmonary artery first ligation group and a pulmonary vein first ligation group. Pin1 mRNA expression in blood samples from patients with lung cancer, controls with benign lung disease, and healthy subjects were determined by a real-time reverse transcriptase polymerase chain reaction. Compared to those with benign lung disease and healthy controls, Pin1 mRNA was overexpressed in patients with non-small-cell lung cancer, and the levels correlated with lymph node-positive disease and tumor stage. Expression of Pin1 mRNA in the distal part of the pulmonary vein was significantly higher than in the proximal part. Postoperative Pin1 mRNA expression was significant lower than preoperative expression. There was no significant difference in Pin1 expression between groups based on pulmonary vessel ligation. These findings suggest that Pin1 might be a useful tumor marker for cancer therapy.