Detection of Androgen Receptor Variant 7 (<i>ARV7)</i> mRNA Levels in EpCAM-Enriched CTC Fractions for Monitoring Response to Androgen Targeting Therapies in Prostate Cancer

Expression of the androgen receptor splice variant 7 (<i>ARV7)</i> in circulating tumor cells (CTCs) has been associated with resistance towards novel androgen receptor (AR)-targeting therapies. While a multitude of ARV7 detection approaches have been developed, the simultaneous enumerat...

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Bibliographic Details
Main Authors: Claudia Hille, Tobias M. Gorges, Sabine Riethdorf, Martine Mazel, Thomas Steuber, Gunhild Von Amsberg, Frank König, Sven Peine, Catherine Alix-Panabières, Klaus Pantel
Format: Article
Language:English
Published: MDPI AG 2019-09-01
Series:Cells
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Online Access:https://www.mdpi.com/2073-4409/8/9/1067
Description
Summary:Expression of the androgen receptor splice variant 7 (<i>ARV7)</i> in circulating tumor cells (CTCs) has been associated with resistance towards novel androgen receptor (AR)-targeting therapies. While a multitude of ARV7 detection approaches have been developed, the simultaneous enumeration of CTCs and assessment of <i>ARV7</i> status and the integration of validated technologies for CTC enrichment/detection into their workflow render interpretation of the results more difficult and/or require shipment to centralized labs. Here, we describe the establishment and technical validation of a novel <i>ARV7</i> detection method integrating the CellSearch<sup>&#174;</sup> technology, the only FDA-cleared CTC-enrichment method for metastatic prostate cancer available so far. A highly sensitive and specific qPCR-based assay was developed, allowing detection of <i>ARV7</i> and <i>keratin 19</i> transcripts from as low as a single <i>ARV7<sup>+</sup>/K19<sup>+</sup></i> cell, even after 24 h of sample storage. Clinical feasibility was demonstrated on blood samples from 26 prostate cancer patients and assay sensitivity and specificity was corroborated. Our novel approach can now be included into prospective clinical trials aimed to assess the predictive values of CTC/ARV7 measurements in prostate cancer.
ISSN:2073-4409