Proteomic-based discovery and characterization of glycosylated eosinophil-derived neurotoxin and COOH-terminal osteopontin fragments for ovarian cancer in urine.
OBJECTIVE
The objective was to identify and characterize low molecular weight proteins/peptides in urine and their posttranslational modifications that might be used as a screening tool for ovarian cancer.


METHODS
Urine samples collected preoperatively from postmenopausal women with ovarian cancer and benign conditions and from nonsurgical controls were analyzed by surface-enhanced laser desorption/ionization mass spectrometry and two-dimensional gel electrophoresis. Selected proteins from mass profiles were purified by chromatography and followed by liquid chromatography-tandem mass spectrometry sequence analysis. Specific antibodies were generated for further characterization, including immunoprecipitation and glycosylation. Quantitative and semiquantitative ELISAs were developed for preliminary validation in patients of 128 ovarian cancer, 52 benign conditions, 44 other cancers, and 188 healthy controls.


RESULTS
A protein (m/z approximately 17,400) with higher peak intensities in cancer patients than in benign conditions and controls was identified and subsequently defined as eosinophil-derived neurotoxin (EDN). A glycosylated form of EDN was specifically elevated in ovarian cancer patients. A cluster of COOH-terminal osteopontin was identified from two-dimensional gels of urine from cancer patients. Modified forms EDN and osteopontin fragments were elevated in early-stage ovarian cancers and a combination of both resulted to 93% specificity and 72% sensitivity.


CONCLUSIONS
Specific elevated posttranslationally modified urinary EDN and osteopontin COOH-terminal fragments in ovarian cancer might lead to potential noninvasive screening tests for early diagnosis. Urine with less complexity than serum and relatively high thermodynamic stability of peptides or metabolites is a promising study medium for discovery of the novel biomarkers which may present in many non-urinary tract neoplastic diseases.
Ye
Bin
B
Laboratory of Gynecologic Oncology, Department of Obstetrics and Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Dana-Farber Cancer Center, 221 Longwood Avenue, LMRC-601B, Boston, MA 02115, USA. Bye@partners.org
Skates
Steven
S
Mok
Samuel C
SC
Horick
Nora K
NK
Rosenberg
Helene F
HF
Vitonis
Allison
A
Edwards
Dale
D
Sluss
Patrick
P
Han
Won K
WK
Berkowitz
Ross S
RS
Cramer
Daniel W
DW
D018262:Adenocarcinoma, Clear Cell / Q000473:pathology / Q000601:surgery / Q000652:urine; D002288:Adenocarcinoma, Mucinous / Q000473:pathology / Q000601:surgery / Q000652:urine; D000595:Amino Acid Sequence; D014408:Biomarkers, Tumor / Q000652:urine*; D018269:Carcinoma, Endometrioid / Q000473:pathology / Q000601:surgery / Q000652:urine; D016022:Case-Control Studies; D018284:Cystadenocarcinoma, Serous / Q000473:pathology / Q000601:surgery / Q000652:urine; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D047208:Eosinophil-Derived Neurotoxin / Q000652:urine*; D005260:Female; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D009361:Neoplasm Invasiveness; D009375:Neoplasms, Glandular and Epithelial / Q000473:pathology / Q000601:surgery / Q000652:urine*; D053495:Osteopontin; D010051:Ovarian Neoplasms / Q000473:pathology / Q000601:surgery / Q000652:urine*; D011379:Prognosis; D020543:Proteome; D012795:Sialoglycoproteins / Q000652:urine*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D014408:Biomarkers, Tumor; D020543:Proteome; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin; D047208:Eosinophil-Derived Neurotoxin