Maldi-TOF analysis of portal sera of pancreatic cancer patients: identification of diabetogenic and antidiabetogenic peptides.
BACKGROUND
Pancreatic cancer (PC) associated diabetes mellitus (DM) might be consequent to the diabetogenic effects of tumour products, possibly acting via nitric oxide (NO). Our aims were: (1) to verify whether PC associated DM determines an increased hepatic NO and (2) using MALDI-TOF analysis, to evaluate the peptide composition of PC cell conditioned media (CM) and of portal sera from patients with PC with (n=7) or without (n=4) DM.


METHODS
In liver tissue homogenates of 23 patients with PC (n=17) or chronic pancreatitis (n=6) GAPDH mRNA and activity, glucose, lactate, nitrite and nitrate were assayed. MALDI-TOF analysis was performed in three PC cell lines CM, and in portal sera from patients with PC.


RESULTS
Higher GAPDH mRNA and nitrite were found in patients with than in patients without DM. In PC cell CM, only 9 among a total of 75 fragments identified, were tumour specific. One hundred seventy-three fragments were identified in the portal sera of patients: one was positively and six fragments were negatively correlated with DM.


CONCLUSIONS
Unlike liver GAPDH, NO appears to be involved in PC associated DM. In portal sera, the absence, rather than the presence, of specific fragments, appears to be correlated with the development of DM.
Valerio
Anna
A
Department of Clinical and Experimental Medicine, University of Padova, Padova, Italy.
Basso
Daniela
D
Fogar
Paola
P
Falconi
Massimo
M
Greco
Eliana
E
Bassi
Claudio
C
Seraglia
Roberta
R
Abu-Hilal
Mohamed
M
Navaglia
Filippo
F
Zambon
Carlo-Federico
CF
Gallo
Nicoletta
N
Falda
Alessandra
A
Pedrazzoli
Sergio
S
Plebani
Mario
M
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D048909:Diabetes Complications / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D005260:Female; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009573:Nitrites / Q000032:analysis; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000150:complications* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D015415:Biomarkers; D009573:Nitrites; D012333:RNA, Messenger; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases