Exosomal Release of L-Plastin by Breast Cancer Cells Facilitates Metastatic Bone Osteolysis

Kerstin Tiedemann; Gulzhakhan Sadvakassova; Nicholas Mikolajewicz; Michal Juhas; Zarina Sabirova; Sébastien Tabariès; Jan Gettemans; Peter M Siegel; Svetlana V Komarova

doi:10.1016/j.tranon.2018.11.014

Exosomal Release of L-Plastin by Breast Cancer Cells Facilitates Metastatic Bone Osteolysis

Transl Oncol. 2019 Mar;12(3):462-474. doi: 10.1016/j.tranon.2018.11.014. Epub 2018 Dec 21.

Authors

Kerstin Tiedemann¹, Gulzhakhan Sadvakassova¹, Nicholas Mikolajewicz¹, Michal Juhas², Zarina Sabirova³, Sébastien Tabariès⁴, Jan Gettemans⁵, Peter M Siegel⁶, Svetlana V Komarova⁷

Affiliations

¹ Faculty of Dentistry, McGill University, 3640 rue University, Montreal, Quebec, Canada, H3A 0C7; Shriner's Hospital for Children - Canada, 1003 Decarie Boulevard, Montreal, Quebec H4A 0A9.
² Faculty of Dentistry, McGill University, 3640 rue University, Montreal, Quebec, Canada, H3A 0C7.
³ Shriner's Hospital for Children - Canada, 1003 Decarie Boulevard, Montreal, Quebec H4A 0A9.
⁴ Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada, H3A 1A3; Department of Medicine, McGill University, Montreal, Quebec, Canada, H3A 1A3.
⁵ Department of Biochemistry, Faculty of Medicine and Health Sciences, Rommelaere Campus, Ghent University, Ghent, Belgium.
⁶ Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada, H3A 1A3; Department of Medicine, McGill University, Montreal, Quebec, Canada, H3A 1A3; Department of Biochemistry, McGill University, Montreal, Quebec, Canada, H3A 1A3.
⁷ Faculty of Dentistry, McGill University, 3640 rue University, Montreal, Quebec, Canada, H3A 0C7; Shriner's Hospital for Children - Canada, 1003 Decarie Boulevard, Montreal, Quebec H4A 0A9. Electronic address: Svetlana.komarova@mcgill.ca.

Abstract

Bone metastasis from breast and prostate carcinomas is facilitated by activation of bone-resorbing osteoclasts. Using proteomics approaches, we have identified peroxiredoxin-4 (PRDX4) as a cancer-secreted mediator of osteoclastogenesis. We now report characterization of L-plastin in the conditioned media (CM) of MDA-MB-231 human breast cancer cells using immunoblotting and mass spectrometry. The osteoclastogenic potential of MDA-MB-231 CM with siRNA-silenced L-plastin was significantly reduced. L-plastin was detected in cancer-derived exosomes, and inhibition of exosomal release significantly decreased the osteoclastogenic capacity of MDA-MB-231 CM. When added to osteoclast precursors primed with RANKL for 2 days, recombinant L-plastin induced calcium/NFATc1-mediated osteoclastogenesis to the levels similar to continuous treatment with RANKL. Using shRNA, we generated MDA-MB-231 cells lacking L-plastin, PRDX4, or both and injected these cell populations intratibially in CD-1 immunodeficient mice. Micro-CT and histomorphometric analysis demonstrated a complete loss of osteolysis when MDA-MB-231 cells lacking both L-plastin and PRDX4 were injected. A meta-analysis established an increase in L-plastin and PRDX4 mRNA expression in numerous human cancers, including breast and prostate carcinomas. This study demonstrates that secreted L-plastin and PRDX4 mediate osteoclast activation by human breast cancer cells.