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Quantitation of HER2 and telomerase biomarkers in solid tumors with IgY antibodies and nanocrystal detection
Author(s) -
Xiao Yan,
Gao Xiugong,
Gannot Gallya,
EmmertBuck Michael R,
Srivastava Sudhir,
Wagner Paul D.,
Amos Michael D.,
Barker Peter E.
Publication year - 2008
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.23320
Subject(s) - telomerase , antibody , polyclonal antibodies , microbiology and biotechnology , biomarker , cancer biomarkers , cancer research , dot blot , prostate cancer , biology , cancer , cish , immunohistochemistry , chemistry , immunology , in situ hybridization , gene , gene expression , biochemistry , genetics
In an effort to improve affinity biomarker validation in fixed patient tissue specimens, we have developed a novel quantum dot‐based bioimaging system that utilizes chicken IgY antibody for high sensitivity and specificity relative quantitation of cancer proteins. Monospecific, polyclonal IgYs were generated against human HER2 and telomerase, and analytically validated for specificity by western blot and immunohistochemistry on tumor and normal cells and for relative affinity by layered peptide array (LPA). IgYs bound desired targets in cell lines and fixed tissues and showed greater affinity than commercial mammalian antibodies for both HER2 and telomerase proteins. In tissue microarray experiments, HER2 quantitation with IgY antibody and quantum dot imaging correlated well with chromogenic in situ hybridization (CISH), whereas telomerase quantitation suggested a trend toward correlation with prostate cancer Gleason Grade and differentiation. Although patient numbers were small, these findings demonstrate the feasibility of relative quantitation of cancer biomarkers with IgY and quantum dot fluorophores, and show promise for rigorous clinical validation in large patient cohorts. © 2008 Wiley‐Liss, Inc.