TY - GEN
T1 - Application of NIR fluorescent markers to quantify expression level of HER2 receptors in carcinomas in vivo
AU - Chernomordik, Victor
AU - Hassan, Moinuddin
AU - Lee, Sang Bong
AU - Zielinski, Rafal
AU - Capala, Jacek
AU - Gandjbakhche, Amir
PY - 2010
Y1 - 2010
N2 - HER2 overexpression has been associated with a poor prognosis and resistance to therapy in breast cancer patients. However, quantitative estimates of this important characteristic have been limited to ex vivo ELISA essays of tissue biopsies and/or PET. We develop a novel approach in optical imaging, involving specific probes, not interfering with the binding of the therapeutic agents, thus, excluding competition between therapy and imaging. Affibody-based molecular probes seem to be ideal for in vivo analysis of HER2 receptors using near-infrared optical imaging. Fluorescence intensity distributions, originating from specific markers in the tumor area, can reveal the corresponding fluorophore concentration. We use temporal changes of the signal from a contrast agent, conjugated with HER2-specific Affibody as a signature to monitor in vivo the receptors status in mice with different HER2 over-expressed tumor models. Kinetic model, incorporating saturation of the bound ligands in the tumor area due to HER2 receptor concentration, is suggested to analyze relationship between tumor cell characteristics, i.e., HER2 overexpression, obtained by traditional ("golden standard") ex vivo methods (ELISA), and parameters, estimated from the series of images in vivo. Observed correlation between these parameters and HER2 overexpression substantiates application of our approach to quantify HER2 concentration in vivo.
AB - HER2 overexpression has been associated with a poor prognosis and resistance to therapy in breast cancer patients. However, quantitative estimates of this important characteristic have been limited to ex vivo ELISA essays of tissue biopsies and/or PET. We develop a novel approach in optical imaging, involving specific probes, not interfering with the binding of the therapeutic agents, thus, excluding competition between therapy and imaging. Affibody-based molecular probes seem to be ideal for in vivo analysis of HER2 receptors using near-infrared optical imaging. Fluorescence intensity distributions, originating from specific markers in the tumor area, can reveal the corresponding fluorophore concentration. We use temporal changes of the signal from a contrast agent, conjugated with HER2-specific Affibody as a signature to monitor in vivo the receptors status in mice with different HER2 over-expressed tumor models. Kinetic model, incorporating saturation of the bound ligands in the tumor area due to HER2 receptor concentration, is suggested to analyze relationship between tumor cell characteristics, i.e., HER2 overexpression, obtained by traditional ("golden standard") ex vivo methods (ELISA), and parameters, estimated from the series of images in vivo. Observed correlation between these parameters and HER2 overexpression substantiates application of our approach to quantify HER2 concentration in vivo.
KW - Clinical applications
KW - HER2 overexpression
KW - Medical and biological imaging
KW - Spectroscopy and fluorescence
UR - http://www.scopus.com/inward/record.url?scp=77951751922&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77951751922&partnerID=8YFLogxK
U2 - 10.1117/12.855652
DO - 10.1117/12.855652
M3 - Conference contribution
AN - SCOPUS:77951751922
SN - 9780819479570
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Optical Biopsy VII
T2 - Optical Biopsy VII
Y2 - 25 January 2010 through 28 January 2010
ER -