HER3-Mediated Resistance to Hsp90 Inhibition Detected in Breast Cancer Xenografts by Affibody-Based PET Imaging.

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Authors

Martins, CD
Da Pieve, C
Burley, TA
Smith, R
Ciobota, DM
Allott, L
Harrington, KJ
Oyen, WJG
Smith, G
Kramer-Marek, G

Document Type

Journal Article

Date

2018-04-15

Date Accepted

2018-02-01

Abstract

Purpose: Recent studies have highlighted a role of HER3 in HER2-driven cancers (e.g., breast cancer), implicating the upregulation of the receptor in resistance to HER-targeted therapies and Hsp90 inhibitors (e.g., AUY922). Therefore, we have developed an affibody-based PET radioconjugate that quantitatively assesses HER3 changes induced by Hsp90 inhibition in vivoExperimental Design: ZHER3:8698 affibody molecules were conjugated via the C-terminus cysteine to DFO-maleimide for 89Zr radiolabeling. The probe was characterized in vitro and in vivo in a panel of human breast cell lines and xenograft models with varying HER3 receptor levels. In addition, the radioconjugate was investigated as a tool to monitor the outcome of AUY922, an Hsp90 inhibitor, in an MCF-7 xenograft model.Results: We demonstrated that 89Zr-DFO-ZHER3:8698 can track changes in receptor expression in HER3-positive xenograft models and monitor the outcome of AUY922 treatment. Our in vitro findings showed that MCF-7 cells, which are phenotypically different from BT474, develop resistance to treatment with AUY922 through HER3/IGF-1Rβ-mediated signaling. Of note, the lack of response in vitro due to HER3 recovery was confirmed in vivo using 89Zr-DFO-ZHER3:8698-based imaging. Upon AUY922 treatment, higher radioconjugate uptake was detected in treated MCF-7 xenografts, correlating with an AUY922-induced HER3 upregulation concomitant with an increase in IGF-1Rβ expression.Conclusions: These data underline the potential of HER3-based PET imaging to noninvasively provide information about HER3 expression and to identify patients not responding to targeted therapies due to HER3 recovery. Clin Cancer Res; 24(8); 1853-65. ©2018 AACR.

Citation

Clinical cancer research : an official journal of the American Association for Cancer Research, 2018, 24 (8), pp. 1853 - 1865

Source Title

Publisher

AMER ASSOC CANCER RESEARCH

ISSN

1078-0432

eISSN

1557-3265

Research Team

PET Radiochemistry
Preclinical Molecular Imaging
Targeted Therapy
Translational Molecular Imaging

Notes