[Immuno-proteomic screening of human pancreatic cancer associated membrane antigens for early diagnosis].
OBJECTIVE
To screen and identify the immunogenic membrane antigens in human pancreatic cancer for early diagnosis.


METHODS
Membrane protein was extracted from pancreatic cancer cell lines and separated by using 2-DE. One of the two parallel 2-DE gels went for staining while the other underwent immunoblot. Serum IgG, which was purified from clinically collected sera of pancreatic cancer patients, was used as the primary antibodies for the immunoblot. Positive dots of immunoblot were identified by MALDI-TOF mass spectrometry and PMF matching, and then evaluated by bio-informatics methods. The candidate membrane antigens were further validated respectively in cell lines and tissues by RT-PCR and immunohistochemistry.


RESULTS
The immunoblot of mixed membrane protein with serum IgG from cancer patients showed eight positive dots. These dots were identified with MALDI and PMF as: VDAC-1, VDAC-2, CHCHD3, SLP-2 and TOM40. RT-PCR showed that these membrane antigens were expressed in several pancreatic cancer cell lines. Immunohistochemistry showed prominent SLP-2 over expression in cancer tissue.


CONCLUSIONS
VDAC-1, VDAC-2, CHCHD3, SLP-2, and TOM40 are the new candidate immunogenic membrane antigens of pancreatic cancer. These membrane antigens can be subsequently tested in high dangerous population for early diagnosis of pancreatic cancer.
Ning
Li
L
Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100730, China.
Pan
Bo
B
Zhao
Yu-pei
YP
Liao
Quan
Q
Zhang
Tai-ping
TP
Chen
Ge
G
Wang
Wei-bin
WB
Yang
Ying-chi
YC
D014408:Biomarkers, Tumor / Q000032:analysis*; D045744:Cell Line, Tumor; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007123:Immunoelectrophoresis, Two-Dimensional; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007150:Immunohistochemistry; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D014408:Biomarkers, Tumor; D007074:Immunoglobulin G; D008565:Membrane Proteins