Cancers, Vol. 13, Pages 3706: Hsp70 in Liquid Biopsies —A Tumor-Specific Biomarker for Detection and Response Monitoring in Cancer

Cancers, Vol. 13, Pages 3706: Hsp70 in Liquid Biopsies—A Tumor-Specific Biomarker for Detection and Response Monitoring in Cancer Cancers doi: 10.3390/cancers13153706 Authors: Caroline Werner Stefan Stangl Lukas Salvermoser Melissa Schwab Maxim Shevtsov Alexia Xanthopoulos Fei Wang Ali Bashiri Dezfouli Dennis Thölke Christian Ostheimer Daniel Medenwald Martin Windberg Matthias Bache Martin Schlapschy Arne Skerra Gabriele Multhoff In contrast to normal cells, tumor cells of multiple entities overexpress the Heat shock protein 70 (Hsp70) not only in the cytosol, but also present it on their plasma membrane in a tumor-specific manner. Furthermore, membrane Hsp70-positive tumor cells actively release Hsp70 in small extracellular vesicles with biophysical characteristics of exosomes. Due to conformational changes of Hsp70 in a lipid environment, most commercially available antibodies fail to detect membrane-bound and vesicular Hsp70. To fill this gap and to assess the role of vesicular Hsp70 in circulation as a potential tumor biomarker, we established the novel complete (comp)Hsp70 sandwich ELISA, using two monoclonal antibodies (mAbs), that is able to recognize both free and lipid-associated Hsp70 on the cell surface of viable tumor cells and on small extracellular vesicles. The epitopes of the mAbs cmHsp70.1 (aa 451–461) and cmHsp70.2 (aa 614–623) that are conserved among different species reside in the substrate-binding domain of Hs...
Source: Cancers - Category: Cancer & Oncology Authors: Tags: Article Source Type: research