Oncogenic role of SFRP2 in p53-mutant osteosarcoma development via autocrine and paracrine mechanism
A partir d'échantillons tumoraux prélevés sur des patients atteints d'un ostéosarcome, puis menée in vitro et in vivo, cette étude met en évidence des mécanismes par lesquels, en lien avec un gène TP53 muté, la protéine SFRP2 favorise la tumorigenèse
Li–Fraumeni syndrome is a rare disorder caused by germline TP53 mutations, predisposing patients to early-onset cancers, including osteosarcoma (OS). Here we demonstrate that strong expression of SFRP2, a reported WNT antagonist, in OS patient samples correlates with poor survival and that SFRP2 overexpression suppresses normal osteoblast differentiation, promotes OS features, and facilitates angiogenesis via autocrine and paracrine mechanisms in an induced pluripotent stem cell disease model. We show that these SFRP2-mediated phenotypes are canonical WNT/β-catenin independent and are mediated through induction of oncogenes such as FOXM1 and CYR61. We further demonstrate that inhibition of SFRP2, FOXM1, or CYR61 represses tumorigenesis. Our data suggest that inhibition of SFRP2 should be explored clinically as a strategy for treatment patients with p53 mutation-associated OS. Osteosarcoma (OS), the most common primary bone tumor, is highly metastatic with high chemotherapeutic resistance and poor survival rates. Using induced pluripotent stem cells (iPSCs) generated from Li–Fraumeni syndrome (LFS) patients, we investigate an oncogenic role of secreted frizzled-related protein 2 (SFRP2) in p53 mutation-associated OS development. Interestingly, we find that high SFRP2 expression in OS patient samples correlates with poor survival. Systems-level analyses identified that expression of SFRP2 increases during LFS OS development and can induce angiogenesis. Ectopic SFRP2 overexpression in normal osteoblast precursors is sufficient to suppress normal osteoblast differentiation and to promote OS phenotypes through induction of oncogenic molecules such as FOXM1 and CYR61 in a β-catenin–independent manner. Conversely, inhibition of SFRP2, FOXM1, or CYR61 represses the tumorigenic potential. In summary, these findings demonstrate the oncogenic role of SFRP2 in the development of p53 mutation-associated OS and that inhibition of SFRP2 is a potential therapeutic strategy.