title: Anti-p21 autoantibodies detected in colorectal cancer patients: A proof of concept study.
abstract: Whereas the presence of autoantibodies in cancer patients has been acknowledged, their diagnostic or therapeutic significance has yet to be established. This is due, at least in part, to the lack of robust screening techniques to detect and characterize such antibodies for further assessment. In this study, we screened colorectal cancer (CRC) patient sera for antibodies specifically targeting the key cell cycle inhibitory factor p21 encoded by the cyclin-dependent kinase inhibitor 1A (CDKN1A). Anti-p21 antibody titers were higher in CRC patient samples versus controls, correlating with a more advanced disease stage and lymph node involvement. Further, we isolated for the first time a specific human antibody fragment against p21, which could potentially be useful as a tool to study tumorigenicity in CRC patients.
authors.affiliation: Division of Gastroenterology; Northwestern University ; Chicago, IL USA.
authors.forename: Faraz
authors.initials: F
authors.lastname: Bishehsari
authors.affiliation: Division of Infectious Diseases; University of California Irvine ; Irvine, CA USA.
authors.forename: Johannes S
authors.initials: JS
authors.lastname: Gach
authors.affiliation: Division of Gastroenterology and Hepatology; University of Illinois at Chicago ; Chicago, IL USA.
authors.forename: Naomi
authors.initials: N
authors.lastname: Akagi
authors.affiliation: School of Medicine; University of Pittsburgh ; Pittsburgh, PA USA.
authors.forename: Molly K
authors.initials: MK
authors.lastname: Webber
authors.affiliation: Division of Gastroenterology and Hepatology; University of Illinois at Chicago ; Chicago, IL USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Bauer
authors.affiliation: Division of Gastroenterology and Hepatology; University of Illinois at Chicago ; Chicago, IL USA.
authors.forename: Barbara H
authors.initials: BH
authors.lastname: Jung
keywords: CDKN1A, cyclin-dependent kinase inhibitor 1; CRC, colorectal cancer; ELISA, enzyme-linked immunosorbent assay; Fab, fragment antigen-binding; HER2/ERBB2, v-erb-b2 avian erythroblastic leukemia viral oncogene homologue 2; Ni-NTA, nickel-charged nitrilotriacetic acid; OD50, half-maximum binding titer; TAAs, tumor-associated antigens; TP53, tumor protein p53.; aAbs, autoantibodies; autoantibody; immunofluorescence assay; olorectal cancer; p21; p21/CIP1, CDKN1A protein; phage display