Proteomic analyses of pancreatic cyst fluids.
OBJECTIVE
There are currently no diagnostic indicators that are consistently reliable, obtainable, and conclusive for diagnosing and risk-stratifying pancreatic cysts. Proteomic analyses were performed to explore pancreatic cyst fluids to yield effective diagnostic biomarkers.


METHODS
We have prospectively recruited 20 research participants and prepared their pancreatic cyst fluids specifically for proteomic analyses. Proteomic approaches applied were as follows: (1) matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry peptidomics with LC/MS/MS (HPLC-tandem mass spectrometry) protein identification; (2) 2-dimensional gel electrophoresis; (3) GeLC/MS/MS (tryptic digestion of proteins fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified by LC/MS/MS).


RESULTS
Sequencing of more than 350 free peptides showed that exopeptidase activities rendered peptidomics of cyst fluids unreliable; protein nicking by proteases in the cyst fluids produced hundreds of protein spots from the major proteins, making 2-dimensional gel proteomics unmanageable; GeLC/MS/MS revealed a panel of potential biomarker proteins that correlated with carcinoembryonic antigen (CEA).


CONCLUSIONS
Two homologs of amylase, solubilized molecules of 4 mucins, 4 solubilized CEA-related cell adhesion molecules (CEACAMs), and 4 S100 homologs may be candidate biomarkers to facilitate future pancreatic cyst diagnosis and risk-stratification. This approach required less than 40 microL of cyst fluid per sample, offering the possibility to analyze cysts smaller than 1 cm in diameter.
Ke
Eileen
E
From the Divisions of *Basic Science, daggerMedical Science, and double daggerPopulation Science, Fox Chase Cancer Center, Philadelphia, PA.
Patel
Bhavinkumar B
BB
Liu
Tiffany
T
Li
Xin-Ming
XM
Haluszka
Oleh
O
Hoffman
John P
JP
Ehya
Hormoz
H
Young
Nancy A
NA
Watson
James C
JC
Weinberg
David S
DS
Nguyen
Minhhuyen T
MT
Cohen
Steven J
SJ
Meropol
Neal J
NJ
Litwin
Samuel
S
Tokar
Jeffrey L
JL
Yeung
Anthony T
AT
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000681:Amylases / Q000032:analysis; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002853:Chromatography, Liquid; D020420:Cyst Fluid / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000032:analysis; D010181:Pancreatic Cyst / Q000378:metabolism*; D011446:Prospective Studies; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D002272:Carcinoembryonic Antigen; D009077:Mucins; D000681:Amylases