Ferrena Alexander, Zhang Ranxin, Wang Jichuan, Zheng Xiang Yu, Göker Barlas, Borjihan Hasibagan, Chae Sung-Suk, Lo Yungtai, Zhao Hongling, Schwartz Edward, Loeb David, Yang Rui, Geller David, Zheng Deyou, Hoang Bang
Institute for Clinical and Translational Research, Albert Einstein College of Medicine, Bronx, NY, USA.
Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA.
bioRxiv. 2024 Jun 6:2024.06.04.597347. doi: 10.1101/2024.06.04.597347.
Osteosarcoma (OS) is the most common primary pediatric bone malignancy. One promising new therapeutic target is , encoding a substrate recognition factor of the SCF E3 ubiquitin ligase responsible for ubiquitination and proteasome degradation of substrate p27, thus driving cellular proliferation. We have shown previously that knockout of in an immunocompetent transgenic mouse model of OS improved survival, drove apoptosis, and induced tumor inflammation. Here, we applied single-cell RNA-sequencing (scRNA-seq) to study primary OS tumors derived from Osx-Cre driven conditional knockout of and . We showed that murine OS models recapitulate the tumor heterogeneity and microenvironment complexity observed in patient tumors. We further compared this model with OS models with functional disruption of : one with knockout and the other with the Skp2-p27 interaction disrupted (resulting in p27 overexpression). We found reduction of T cell exhaustion and upregulation of interferon activation, along with evidence of replicative and endoplasmic reticulum-related stress in the disruption models, and showed that interferon induction was correlated with improved survival in OS patients. Additionally, our scRNA-seq analysis uncovered decreased activities of metastasis-related gene signatures in the -disrupted OS, which we validated by observation of a strong reduction in lung metastasis in the knockout mice. Finally, we report several potential mechanisms of escape from targeting in OS, including upregulation of targets, DNA copy number amplification and overexpression of alternative E3 ligase genes, and potential alternative lineage activation. These mechanistic insights into OS tumor biology and function suggest novel targets for new, synergistic therapies, while the data and our comprehensive analysis may serve as a public resource for further big data-driven OS research.
骨肉瘤（OS）是最常见的原发性儿童骨恶性肿瘤。一个有前景的新治疗靶点是 ，它编码SCF E3泛素连接酶的底物识别因子，负责底物p27的泛素化和蛋白酶体降解，从而驱动细胞增殖。我们之前已经表明，在具有免疫活性的OS转基因小鼠模型中敲除 可提高生存率、促进细胞凋亡并诱导肿瘤炎症。在此，我们应用单细胞RNA测序（scRNA-seq）来研究源自Osx-Cre驱动的 和 条件性敲除的原发性OS肿瘤。我们表明，小鼠OS模型概括了在患者肿瘤中观察到的肿瘤异质性和微环境复杂性。我们进一步将该模型与功能破坏 的OS模型进行比较：一个是 敲除模型，另一个是Skp2-p27相互作用被破坏（导致p27过表达）的模型。我们发现在 破坏模型中T细胞耗竭减少且干扰素激活上调，同时有复制和内质网相关应激的证据，并表明干扰素诱导与OS患者生存率提高相关。此外，我们的scRNA-seq分析发现，在 破坏的OS中转移相关基因特征的活性降低，我们通过观察 敲除小鼠肺转移的显著减少来验证这一点。最后，我们报告了OS中逃避靶向 的几种潜在机制，包括 靶点的上调、DNA拷贝数扩增和替代E3连接酶基因的过表达，以及潜在的替代谱系激活。这些对OS肿瘤生物学和 功能的机制性见解提示了新的协同治疗的新靶点，而这些数据和我们的全面分析可能作为进一步大数据驱动的OS研究的公共资源。
