We have previously reported the expression of parathyroid hormone-like hormone (PTHLH) in well-differentiated, Schwannian stroma-rich neuroblastic tumors. The aim of this study was to functionally assess the role of PTHLH and its receptor, PTH1R, in neuroblastoma. Stable knockdown of PTHLH and PTH1R was conducted in neuroblastoma cell lines to investigate the succeeding phenotype induced both in vitro and in vivo. Downregulation of PTHLH reduced MYCN expression and subsequently induced cell cycle arrest, senescence, and migration and invasion impairment in a MYCN-amplified, TP53-mutated neuroblastoma cell line. These phenotypes were associated with reduced tumorigenicity in a murine model. We also show that PTHLH expression is not under the control of the calcium-sensing receptor in neuroblastoma. Conversely, its production is stimulated by epidermal growth factor receptor (EGFR). Accordingly, irreversible EGFR inhibition with canertinib abolished PTHLH expression. The oncogenic role of PTHLH appeared to be a consequence of its intracrine function, as downregulation of its receptor, PTH1R, increased anchorage-independent growth and induced a more undifferentiated, invasive phenotype. Respectively, high PTH1R mRNA expression was found in MYCN nonamplified primary tumors and also significantly associated with other prognostic factors of good outcome. This study provides the first evidence of the dual role of PTHLH in the behavior of neuroblastomas. Moreover, the identification of EGFR as a transcriptional regulator of PTHLH in neuroblastoma provides a novel therapeutic opportunity to promote a less aggressive tumor phenotype through irreversible inhibition of EGFR tyrosine kinase activity.

中文翻译：

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甲状旁腺激素样激素在神经母细胞瘤中起双重作用，这取决于PTH1R的表达。

我们以前曾报道过分化良好的施万尼基质丰富的神经母细胞瘤中甲状旁腺激素样激素（PTHLH）的表达。这项研究的目的是功能上评估PTHLH及其受体PTH1R在神经母细胞瘤中的作用。在神经母细胞瘤细胞系中进行了PTHLH和PTH1R的稳定敲低研究，以研究在体外和体内诱导的后续表型。PTHLH的下调降低了MYCN的表达，并随后在MYCN扩增的TP53突变的神经母细胞瘤细胞系中诱导了细胞周期停滞，衰老以及迁移和侵袭损伤。这些表型与鼠模型的致瘤性降低有关。我们还显示PTHLH表达不受神经母细胞瘤中钙敏感受体的控制。反过来，它的产生受到表皮生长因子受体（EGFR）的刺激。因此，canertinib对EGFR的不可逆抑制作用消除了PTHLH表达。PTHLH的致癌作用似乎是其内分泌功能的结果，因为其受体PTH1R的下调，锚定非依赖性生长增加并诱导了更未分化的侵袭性表型。分别在MYCN未扩增的原发性肿瘤中发现了高PTH1R mRNA表达，并且还与其他预后良好的预后因素显着相关。这项研究提供了PTHLH在神经母细胞瘤行为中的双重作用的第一个证据。此外，