Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio.
Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.
Mol Cancer Ther. 2021 May;20(5):803-815. doi: 10.1158/1535-7163.MCT-20-0749. Epub 2021 Mar 1.
, the most common fusion gene in Ewing sarcoma, upregulates expression of the Eyes Absent 3 (EYA3) transactivator-phosphatase protein. The purpose of this study was to investigate molecular and cellular mechanisms through which EYA3 might promote Ewing sarcoma tumor growth and to determine whether the EYA3 tyrosine phosphatase activity represents a viable therapeutic target. We used genetic and pharmacologic modulation of EYA3 in cell line-based xenografts to examine how loss of EYA3 tyrosine phosphatase activity affects tumor growth and angiogenesis. Molecular mechanisms were evaluated and through analyses of tumor tissue and multicellular tumor spheroids. Our results show that both loss of EYA3 in Ewing sarcoma cells and pharmacologic inhibition of the EYA3 tyrosine phosphatase activity inhibit tumor growth and tumor angiogenesis. EYA3 regulates levels of VEGFA in Ewing tumors, as well as promoting DNA damage repair and survival of Ewing sarcoma tumor cells. Target engagement is demonstrated in tumor tissue through elevated levels of the EYA3 substrate H2AX-pY142 upon loss of EYA3 or with Benzarone treatment. The efficacy of EYA3 tyrosine phosphatase inhibition in attenuating tumor growth and angiogenesis is corroborated in an Ewing sarcoma patient-derived tumor xenograft. Together, the results presented here validate EYA3 as a target for the development of novel Ewing sarcoma therapeutic strategies, and set the stage for evaluating the efficacy of combining the antiangiogenic and anti-cell survival effects of EYA3 inhibition with cytotoxic chemotherapy.
EWS 最常见的融合基因，上调 Eyes Absent 3（EYA3）转录激活-磷酸酶蛋白的表达。本研究旨在探讨 EYA3 促进尤因肉瘤肿瘤生长的分子和细胞机制，并确定 EYA3 酪氨酸磷酸酶活性是否代表可行的治疗靶点。我们使用基于细胞系的异种移植中的 EYA3 遗传和药理学调节来研究丧失 EYA3 酪氨酸磷酸酶活性如何影响肿瘤生长和血管生成。通过肿瘤组织和多细胞肿瘤球体的分析评估了分子机制。我们的结果表明，EWS 肉瘤细胞中 EYA3 的缺失和 EYA3 酪氨酸磷酸酶活性的药理学抑制均抑制肿瘤生长和肿瘤血管生成。EYA3 调节 Ewing 肿瘤中 VEGFA 的水平，同时促进 Ewing 肉瘤肿瘤细胞的 DNA 损伤修复和存活。通过丧失 EYA3 或用 Benzarone 治疗后 H2AX-pY142 的 EYA3 底物水平升高，在肿瘤组织中证明了靶标结合。在 Ewing 肉瘤患者来源的肿瘤异种移植中，EYA3 酪氨酸磷酸酶抑制在减弱肿瘤生长和血管生成方面的疗效得到了证实。总之，这里呈现的结果验证了 EYA3 作为开发新型尤因肉瘤治疗策略的靶点，并为评估 EYA3 抑制的抗血管生成和抗细胞存活作用与细胞毒性化疗相结合的疗效奠定了基础。
