title: Enhancement of ovarian tumor classification by improved reproducibility in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of serum glycans.
abstract: The serum N-glycome is a promising source of biomarker discovery. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) profiling of serum N-glycans was attempted for differentiating borderline ovarian tumor from benign cases, for which a low data spread is essential. An experimental protocol using matrix-prespotted MALDI plates and fast vacuum drying of the loaded N-glycan samples was developed, thereby minimizing the intensity variations in the replicates to an average relative standard deviation (RSD) of 3.96% for the highest N-glycan peak (m/z 1485.53) of the Sigma-Aldrich serum standard. When applied to sera of ovarian tumors, this procedure exhibited an average RSD of 5.74% for m/z 1485.53 and of 7.28% for all MS peaks. This improved reproducibility combined with the OVA-Beyond(®) screening software resulted in 75.1% and 79.4% correct classification for benign and borderline tumor samples, respectively, while the classification rates by the conventional ovarian tumor marker CA-125 were 54.4% and 53.1%, respectively. Both true positive rate and true negative rate fluctuated with small numbers of markers and converged as the number of markers increased. Cross-validations were performed in comparison with CA-125. These results suggest that our optimized process for MALDI-TOF MS of the serum glycome has a great potential for the screening of early stage ovarian cancer.
authors: ASTA, Inc., Gyeonggi Biocenter, Eui-dong, Youngtong-gu, Suwon 443-270, South Korea.
authors: Chang Won
authors: CW
authors: Park
authors: Yohahn
authors: Y
authors: Jo
authors: Eung Joon
authors: EJ
authors: Jo
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood*; D018394:CA-125 Antigen / Q000097:blood; D018291:Cystadenoma, Mucinous / Q000097:blood* / Q000175:diagnosis; D018293:Cystadenoma, Serous / Q000097:blood* / Q000175:diagnosis; D003937:Diagnosis, Differential; D004715:Endometriosis / Q000097:blood / Q000175:diagnosis; D005260:Female; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000097:blood* / Q000175:diagnosis; D011134:Polysaccharides / Q000097:blood*; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013724:Teratoma / Q000097:blood* / Q000175:diagnosis
chemical_list: D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; D011134:Polysaccharides
keywords: MALDI–TOF; Mass spectrometry; Matrix-prespotted plate; N-glycan; RSD