Platelet-Derived TGF-β Induces Tissue Factor Expression via the Smad3 Pathway in Osteosarcoma Cells

Abstract

Over the last three decades, the prognosis of osteosarcoma has remained unchanged; the prognosis for patients with lung metastasis is still poor, and the development of new treatments is urgently required. We previously showed that aggressive osteosarcoma cells express more tissue factor (TF) and demonstrate enhanced extrinsic pathway capacity. Furthermore, tumor growth can be suppressed with the anticoagulant low molecular weight heparin. However, the molecular mechanisms underlying TF regulation are still unclear. Here, we report that transforming growth factor-β (TGF-β) upregulates TF, which can occur via activated platelets. TF was found to be expressed on osteosarcoma cell surfaces, which mediated the production of Xa and thrombin. TF induction by TGF-β was observed in several osteosarcoma cells, and especially in MG 63 cells. Both TF expression by TGF-β and extrinsic pathway activity through TF were rapidly increased. This reaction was inhibited by a TGF-β type I receptor inhibitor and TGF-β neutralizing antibody. Although TGF-β was found to phosphorylate both Smad2 and Smad3, their roles were markedly disparate. Surprisingly, Smad2 knockdown resulted in no inhibitory effect, whereas Smad3 knockdown completely suppressed TGF-β-induced TF expression. Next, data suggested that platelets were the source of TGF-β. We confirmed that thrombin-activated platelets and osteosarcoma cells could release TGF-β, and that platelet-derived TGF-β could induce TF expression. These processes were also inhibited by a TGF-β type I receptor inhibitor and Smad3 knockdown. Moreover, CD42b, TF, TGF-β, Smad2/3, and p-Smad2/3 were also detected in a biopsy sample from an osteosarcoma patient. Collectively, these finding suggested that the interaction between osteosarcoma cells and platelets, via thrombin and TGF-β, results in a continuous cycle, and that anti-platelet or anti-TGF-β therapy could be a promising tool for disease treatment. © 2018 American Society for Bone and Mineral Research.

Beyond thrombosis: the impact of tissue factor signaling in cancer

“…For example, hepatocyte growth factor (HGF) upregulates TF by activating Met in a Src kinasedependent manner [82]. Other growth factors, including basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF)-BB, PDGF-CC, PDGF-AA, bone morphogenetic protein-7 (BMP-7), transforming growth factor-β (TGF-β), and vascular endothelial growth factor (VEGF) can also increase TF [83][84][85][86][87][88][89][90]. During inflammation, TF can be upregulated by a variety of cytokines and signaling molecules, including interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), IL-6, IL-1β, IL-33, and histamine [91][92][93][94][95][96][97][98][99].…”

miR-16-5p Suppresses Progression and Invasion of Osteosarcoma via Targeting at Smad3

“…Moreover, significant expressions of CD42b, TF, TGF-b, Smad2/3, and p-Smad2/3 were also detected in a biopsy sample from an osteosarcoma patient compared with control. Collectively, these finding suggested that the interaction between osteosarcoma cells and platelets, via thrombin and TGF-b, results in a continuous cycle, and that anti-TGF-b or anti-Smad3 therapy could be a promising tool for disease treatment (Saito et al, 2018).…”

Role of Platelet C-Type Lectin-Like Receptor 2 in Promoting Lung Metastasis in Osteosarcoma

“…( 20 ) Subsequently, we found that platelet‐derived TGF‐β1 increased the expression of tissue factor via Smad3. ( 17 ) These findings suggested that the development of platelet‐targeting therapy is a promising avenue for the treatment of osteosarcoma.…”