Circulating autoantibodies to phosphorylated α-enolase are a hallmark of pancreatic cancer.
Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis and no diagnostic markers have, as of yet, been defined. In PDAC patients, α-enolase (ENOA) is up-regulated and elicits the production of autoantibodies. Here, we analyzed the autoantibody response to post-translational modifications of ENOA in PDAC patients. ENOA isolated from PDAC tissues and cell lines was characterized by two-dimensional electrophoresis (2-DE) Western blot (WB), revealing the expression of six different isoforms (named ENOA1,2,3,4,5,6) whereas only 4 isoforms (ENOA3,4,5,6) were detectable in normal tissues. As assessed by 2-DE WB, 62% of PDAC patients produced autoantibodies to the two more acidic isoforms (ENOA1,2) as opposed to only 4% of controls. Mass spectrometry showed that ENOA1,2 isoforms were phosphorylated on serine 419. ROC analysis demonstrated that autoantibodies to ENOA1,2 usefully complement the diagnostic performance of serum CA19.9 levels, achieving approximately 95% diagnostic accuracy in both advanced and resectable PDAC. Moreover, the presence of autoantibodies against ENOA1,2 correlated with a significantly better clinical outcome in advanced patients treated with standard chemotherapy. In conclusion, our results demonstrate that ENOA phosphorylation is associated with PDAC and induces specific autoantibody production in PDAC patients that may have diagnostic value.
Tomaino
Barbara
B
Center for Experimental Research and Medical Studies (CeRMS), San Giovanni Battista Hospital, Turin, Italy.
Cappello
Paola
P
Capello
Michela
M
Fredolini
Claudia
C
Sperduti
Isabella
I
Migliorini
Paola
P
Salacone
Paola
P
Novarino
Anna
A
Giacobino
Alice
A
Ciuffreda
Libero
L
Alessio
Massimo
M
Nisticò
Paola
P
Scarpa
Aldo
A
Pederzoli
Paolo
P
Zhou
Weidong
W
Petricoin Iii
Emanuel F
EF
Liotta
Lance A
LA
Giovarelli
Mirella
M
Milella
Michele
M
Novelli
Francesco
F
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000378:metabolism; D001323:Autoantibodies / Q000097:blood* / Q000378:metabolism; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000097:blood / Q000175:diagnosis*; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000097:blood / Q000175:diagnosis*; D010751:Phosphopyruvate Hydratase / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011379:Prognosis; D016016:Proportional Hazards Models; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D012372:ROC Curve
D000951:Antigens, Neoplasm; D001323:Autoantibodies; D020033:Protein Isoforms; D010751:Phosphopyruvate Hydratase