Pancreatitis‐Associated Protein Is Related Closely to Neoplastic Proliferative Activity in Patients with Colorectal Carcinoma

Abstract

Pancreatitis-associated protein (PAP) is a secretory protein that is not only expressed during acute pancreatitis but also in pancreatic adenocarcinoma, gastric carcinoma, hepatocellular carcinoma, and colorectal carcinoma. Expression in carcinoma might be another characteristic of PAP. The aim of our study was to assess, in 27 patients undergoing surgery for colorectal carcinoma, the expression of the PAP mRNA and to evaluate its association with DNA ploidy and proliferative activity (S-phase fraction, SPF) by reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometric analysis (FCM). PAP mRNA was expressed in 29.6% (8 of 27) of the patients with colorectal carcinoma. DNA aneuploid and high SPF were found in 87.5% (7 of 8) of patients with PAP mRNA positive colorectal carcinoma. The serum PAP level was significantly elevated in patients with colorectal carcinoma when compared with the healthy subjects. Twelve of the 27 patients with colorectal carcinoma had high serum PAP concentrations (>25 ng/mL) and the mean SPF was 17.82% +/- 8.02%, which was significantly higher compared with the normal colorectal tissue group (7.33% +/- 3.18%, P < 0.05). The mean serum PAP concentration of DNA aneuploidy colorectal carcinomas was 46.67 +/- 17.58 ng/mL, which was significantly different when compared with the DNA diploidy group (19.18 +/- 8.89 ng/mL, P < 0.05). PAP mRNA expression and serum PAP levels are closely related to neoplastic proliferative activity in patients with colorectal carcinoma. No significant differences are observed between PAP mRNA expression and clinicopathologic parameters (P > 0.05).