The proteome of postsurgical pancreatic juice

Abstract

Objective: This study aimed to evaluate the proteome of the pancreatic juice after pancreatectomy.

Methods: Pancreatic juice samples were obtained during surgery and the postoperative period. Proteins were identified by mass spectrometry-based protein quantification technology and compared with published data of the nonoperated pancreas. Subgroup analyses were done in patients with pancreatic ductal adenocarcinoma (PDAC) receiving neoadjuvant chemotherapy and in smokers.

Results: Five hundred eighteen proteins were identified in the postoperative pancreatic juice, encompassing all of the main organ functions. Sixty-seven of these were also present in the published data of the nonoperated pancreas and 7 of these had significant variation of concentration after surgery. Growth factors that have been described in postsurgical regeneration of the liver were not found to be overexpressed, whereas clusterin did, confirming the finding of previous experimental studies on pancreatic regeneration. Several proteins involved in immunomodulation and organ functions were differently expressed, depending on PDAC, neoadjuvant therapy, and smoking.

Conclusions: The proteome of the pancreas after surgical resection contains factors related to all main organ functions, changes over time, and is different in patients with PDAC receiving neoadjuvant therapy and in smokers. The pancreas reacts to the surgical trauma by producing proteins that protect the organ and stimulate the restoration of its function.

FIGURE 1

General mass spectrometry workflow.

FIGURE 2

Panther database analysis grouping proteins identified in our proteomic analysis by molecular function (A) and biological process (B).

FIGURE 3

Venn diagrams comparing proteins identified in the following: (A) this study versus a recent study analyzing normal PJ (high-confidence proteins only) and (B) this study versus 6 recent PJ studies (5 cancer studies and 1 normal PJ study).^,,–

FIGURE 4

Histograms illustrating statistically significant proteins in the time course study. Error bars represent standard error of the mean (n = 4 patients). POD indicates postoperative day.

FIGURE 5

Histograms illustrating statistically significant proteins when comparing cohorts with and without PDAC. Error bars represent standard error of the mean (n = 11 patients).

FIGURE 6

Histograms illustrating statistically significant proteins when comparing cohorts of up-front surgery (none) versus adjuvant treatment. Error bars represent standard error of the mean (n = 11 patients).

FIGURE 7

Histograms illustrating statistically significant proteins when comparing cohorts of smokers versus nonsmokers. Error bars represent standard error of the mean (n = 11 patients).