Princess Margaret Cancer Centre, Princess Margaret Cancer Research Tower, University Health Network, 101 College Street, Room 9-807, Toronto, ON, M5G 1L7, Canada.
Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada.
Acta Neuropathol Commun. 2024 Mar 7;12(1):39. doi: 10.1186/s40478-024-01751-w.
Chordomas are clinically aggressive tumors with a high rate of disease progression despite maximal therapy. Given the limited therapeutic options available, there remains an urgent need for the development of novel therapies to improve clinical outcomes. Cell surface proteins are attractive therapeutic targets yet are challenging to profile with common methods. Four chordoma cell lines were analyzed by quantitative proteomics using a differential ultracentrifugation organellar fractionation approach. A subtractive proteomics strategy was applied to select proteins that are plasma membrane enriched. Systematic data integration prioritized PLA2R1 (secretory phospholipase A2 receptor-PLA2R1) as a chordoma-enriched surface protein. The expression profile of PLA2R1 was validated across chordoma cell lines, patient surgical tissue samples, and normal tissue lysates via immunoblotting. PLA2R1 expression was further validated by immunohistochemical analysis in a richly annotated cohort of 25-patient tissues. Immunohistochemistry analysis revealed that elevated expression of PLA2R1 is correlated with poor prognosis. Using siRNA- and CRISPR/Cas9-mediated knockdown of PLA2R1, we demonstrated significant inhibition of 2D, 3D and in vivo chordoma growth. PLA2R1 depletion resulted in cell cycle defects and metabolic rewiring via the MAPK signaling pathway, suggesting that PLA2R1 plays an essential role in chordoma biology. We have characterized the proteome of four chordoma cell lines and uncovered PLA2R1 as a novel cell-surface protein required for chordoma cell survival and association with patient outcome.
软骨肉瘤是一种临床侵袭性肿瘤，尽管采用了最大程度的治疗，但疾病仍有很高的进展率。鉴于目前可用的治疗方法有限，因此迫切需要开发新的治疗方法来改善临床结果。细胞表面蛋白是很有吸引力的治疗靶点，但用常规方法进行分析具有挑战性。我们采用差异超速离心细胞器分离方法，通过定量蛋白质组学对 4 种软骨肉瘤细胞系进行了分析。应用消减蛋白质组学策略选择富含质膜的蛋白。系统的数据整合将 PLA2R1（分泌型磷脂酶 A2 受体-PLA2R1）作为软骨肉瘤富集的表面蛋白进行了优先级排序。通过免疫印迹法，在软骨肉瘤细胞系、患者手术组织样本和正常组织裂解物中验证了 PLA2R1 的表达谱。通过在 25 例患者组织的丰富注释队列中进行免疫组织化学分析，进一步验证了 PLA2R1 的表达。免疫组织化学分析表明，PLA2R1 的高表达与预后不良相关。通过 siRNA 和 CRISPR/Cas9 介导的 PLA2R1 敲低，我们证明了 PLA2R1 抑制 2D、3D 和体内软骨肉瘤生长的显著作用。PLA2R1 耗竭通过 MAPK 信号通路导致细胞周期缺陷和代谢重编程，表明 PLA2R1 在软骨肉瘤生物学中发挥着重要作用。我们已经对 4 种软骨肉瘤细胞系的蛋白质组进行了描述，并揭示了 PLA2R1 是一种新型的细胞表面蛋白，是软骨肉瘤细胞存活和与患者预后相关所必需的。
