Auto-antibodies to β-F1-ATPase and vimentin in malignant mesothelioma.
Patients with Malignant Mesothelioma (MM) develop unidentified auto-antibodies to MM tumour antigens. This study was conducted to identify the targets of MM patient auto-antibodies in order to try to understand more of the anti-tumour response and to determine if these antibodies might be helpful for diagnosis or prognostication. Using MM patient sera in a Western immunoblott screening strategy, no common immunoreactive proteins were identified. The sera from one long-term survivor recognised a protein band of 50-60 kDa present in cell lysates from four of five MM cell lines tested. The immunoreactive proteins in this band were identified by 2D electrophoretic separation of a MM cell line protein lysate, followed by analysis of excised immunoreactive proteins on a MALDI TOF mass spectrometer and peptide mass fingerprinting. The immunoreactive proteins identified were vimentin (accession gi55977767) and the ATP synthase (F1-ATPase) beta chain (accession gi114549 and gi47606749). ELISA assays were developed for antibodies to these proteins. Neither vimentin (median and 95% CI 0.346; 0.32-0.468 for MM patients, 0.327; 0.308-0.428 for controls) nor ß-F1-ATPase (0.257; 0.221-0.453 for MM patients, 0.263; 0.22-0.35 for controls) showed significant differences in autoantibody levels between a group of MM patients and controls. Using a dichotomized antibody level (high, low) for these targets we demonstrated that vimentin antibody levels were not associated with survival. In contrast, high ß-F1-ATPase antibody levels were significantly associated with increased median survival (18 months) compared to low ß F1 ATPase antibody levels (9 months; p = 0.049). Immunohistochemical analysis on a MM tissue microarray showed cytoplasmic staining in 28 of 33 samples for vimentin and strong cytoplasmic staining in14 and weak in 16 samples for ß-F1-ATPase. Therefore antibodies to neither vimentin nor ß-F1-ATPase are useful for differential diagnosis of MM, however high antibody levels to ß-F1-ATPase may be associated with increased survival and this warrants further investigation.
National Centre for Asbestos Related Diseases, University of Western Australia, School of Medicine and Pharmacology, Nedlands, Western Australia, Australia. creaneyj@cyllene.uwa.edu.au
Jenette
J
Creaney
Ian M
IM
Dick
Deborah
D
Yeoman
Sarah
S
Wong
Bruce W S
BW
Robinson
D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D015153:Blotting, Western; D002457:Cell Extracts; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008654:Mesothelioma / Q000097:blood* / Q000201:enzymology / Q000276:immunology*; D008875:Middle Aged; D025261:Mitochondrial Proton-Translocating ATPases / Q000737:chemistry / Q000276:immunology*; D008969:Molecular Sequence Data; D011379:Prognosis; D021381:Protein Transport; D016415:Sequence Alignment; D016019:Survival Analysis; D014746:Vimentin / Q000737:chemistry / Q000276:immunology*
C506526:ATP5F1B protein, human; D001323:Autoantibodies; D002457:Cell Extracts; D014746:Vimentin; D025261:Mitochondrial Proton-Translocating ATPases