title: Rapid discovery and identification of a tissue-specific tumor biomarker from 39 human cancer cell lines using the SELDI ProteinChip platform.
abstract: Useful biomarkers are needed for early detection of cancers. To demonstrate the potential diagnostic usefulness of a new proteomic technology, we performed Expression Difference Mapping analysis on 39 cancer cell lines from 9 different tissues using ProteinChip technology. A protein biomarker candidate of 12kDa was found in colon cancer cells. We then optimized the purification conditions for this biomarker by utilizing Retentate Chromatography mass spectrometry (RC-MS). The optimized purification conditions developed "on-chip" were directly transferred to conventional chromatography to purify the biomarker, which was identified as prothymosin-alpha by ProteinChip time-of-flight mass spectrometry (TOF MS) and ProteinChip-Tandem MS systems. The relative expression level of prothymosin-alpha between colon cancer cells and normal colon mucosal cells was evaluated on the same ProteinChip platform. Prothymosin-alpha expression in colon cancer cells was clearly higher than in normal colon cells. These results indicate that prothymosin-alpha could be a potential biomarker for colon cancer, and that the ProteinChip platform could perform the whole process of biomarker discovery from screening to evaluation of the identified marker.
authors.affiliation: Yokohama Laboratory, Ciphergen Biosystems K.K., Yokohama Business Park East Tower 14F, 134 Godo-cho, Hodogaya-ku, Yokohama, Kanagawa, Japan.
authors.forename: Mieko
authors.initials: M
authors.lastname: Shiwa
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Rumi
authors.initials: R
authors.lastname: Wakatabe
authors.forename: Ai
authors.initials: A
authors.lastname: Fukawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Arikuni
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ota
authors.forename: Yo
authors.initials: Y
authors.lastname: Kato
authors.forename: Takao
authors.initials: T
authors.lastname: Yamori
mesh_terms: D014408:Biomarkers, Tumor; D003106:Colon / Q000166:cytology / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D013058:Mass Spectrometry; D040081:Protein Array Analysis / Q000379:methods*; D011498:Protein Precursors / Q000096:biosynthesis; D013947:Thymosin / Q000031:analogs & derivatives* / Q000096:biosynthesis; D014357:Trypsin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; D011498:Protein Precursors; C040782:prothymosin alpha; D013947:Thymosin; D014357:Trypsin