[HTML][HTML] Platelet-derived growth factor receptor-α and-β promote cancer stem cell phenotypes in sarcomas

KK Chang, C Yoon, BC Yi, WD Tap, MC Simon… - Oncogenesis, 2018 - nature.com
KK Chang, C Yoon, BC Yi, WD Tap, MC Simon, SS Yoon
Oncogenesis, 2018nature.com
Sarcomas are malignant tumors derived from mesenchymal tissues and may harbor a
subset of cells with cancer stem-like cell (CSC) properties. Platelet-derived growth factor
receptors α and β (PDGFR-α/β) play an important role in the maintenance of mesenchymal
stem cells. Here we examine the role of PDGFR-α/β in sarcoma CSCs. PDGFR-α/β activity
and the effects of PDGFR-α/β inhibition were examined in 3 human sarcoma cell lines using
in vitro assays and mouse xenograft models. In all three cell lines, PDGFR-α/β activity was …
Abstract
Sarcomas are malignant tumors derived from mesenchymal tissues and may harbor a subset of cells with cancer stem-like cell (CSC) properties. Platelet-derived growth factor receptors α and β (PDGFR-α/β) play an important role in the maintenance of mesenchymal stem cells. Here we examine the role of PDGFR-α/β in sarcoma CSCs. PDGFR-α/β activity and the effects of PDGFR-α/β inhibition were examined in 3 human sarcoma cell lines using in vitro assays and mouse xenograft models. In all three cell lines, PDGFR-α/β activity was significantly higher in cells grown as spheroids (to enrich for CSCs) and in cells sorted for CD133 expression (a marker of sarcoma CSCs). Self-renewal transcription factors Nanog, Oct4, and Slug and epithelial-to-mesenchymal transition (EMT) proteins Snail, Slug, and Zeb1 were also significantly higher in spheroids cells and CD133(+) cells. Spheroid cells and CD133(+) cells demonstrated 2.9- to 4.2-fold greater migration and invasion and resistance to doxorubicin chemotherapy. Inhibition of PDGFR-α/β in CSCs using shRNA or pharmacologic inhibitors reduced expression of certain self-renewal and EMT proteins, reduced spheroid formation by 74–82%, reduced migration and invasion by 73–80%, and reversed chemotherapy resistance. In mouse xenograft models, combining PDGFR-α/β inhibition (using shRNA or imatinib) with doxorubicin had a more-than-additive effect in blocking tumor growth, with enhanced apoptosis, especially in CD133(+) cells. These results indicate that PDGFR-α/β activity is upregulated in sarcoma CSCs and promote CSC phenotypes including migration, invasion, and chemotherapy resistance. Thus, the PDGFR-α/β pathway represents a new potential therapeutic target to reduce metastatic potential and increase chemosensitivity.
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