Data_Sheet_1_Genomic and Transcriptomic Characterization of Canine Osteosarcoma Cell Lines: A Valuable Resource in Translational Medicine.XLSX

Osteosarcoma (OSA) represents the most common primary bone tumor in dogs and is characterized by a highly aggressive behavior. Cell lines represent one of the most suitable and reproducible pre-clinical models, and therefore the knowledge of their molecular landscape is mandatory to investigate oncogenic mechanisms and drug response. The present study aims at determining variants, putative driver genes, and gene expression aberrations by integrating whole-exome and RNA sequencing. For this purpose, eight canine OSA cell lines and one matched pair of primary tumor and normal tissue were analyzed. Overall, cell lines revealed a mean tumor mutational burden of 9.6 mutations/Mb (range 3.9–16.8). Several known oncogenes and tumor suppressor genes, such as ALK, MYC, and MET, were prioritized as having a likely role in canine OSA. Mutations in eight genes, previously described as human OSA drivers and including TP53, PTCH1, MED12, and PI3KCA, were retrieved in our cell lines. When variants were cross-referenced with human OSA driver mutations, the E273K mutation of TP53 was identified in the Wall cell line and tumor sample. The transcriptome profiling detected two possible p53 inactivation mechanisms in the Wall cell line on the one hand, and in D17 and D22 on the other. Moreover, MET overexpression, potentially leading to MAPK/ERK pathway activation, was observed in D17 and D22 cell lines. In conclusion, our data provide the molecular characterization of a large number of canine OSA cell lines, allowing future investigations on potential therapeutic targets and associated biomarkers. Notably, the Wall cell line represents a valuable model to empower prospective in vitro studies both in human and in dogs, since the TP53 driver mutation was maintained during cell line establishment and was widely reported as a mutation hotspot in several human cancers.

骨肉瘤（Osteosarcoma, OSA）是犬类最常见的原发性骨肿瘤，其生物学行为具有高度侵袭性。细胞系是最为适用且可重复的临床前模型之一，因此解析其分子图谱对于探究致癌机制与药物反应具有必要性。本研究通过整合全外显子组测序与RNA测序，旨在鉴定变异位点、潜在驱动基因以及基因表达异常。本次研究共纳入8株犬OSA细胞系，以及1对匹配的原发肿瘤与正常组织样本。整体来看，所分析的细胞系平均肿瘤突变负荷为9.6突变/Mb（区间为3.9–16.8）。研究筛选出多个已知癌基因与抑癌基因，包括ALK、MYC及MET，提示这些基因可能在犬OSA的发生发展中发挥关键作用。在本研究的细胞系中，检出8个此前被报道为人类OSA驱动基因的突变位点，涵盖TP53、PTCH1、MED12与PI3KCA。将本次检出的变异位点与人类OSA驱动突变进行交叉比对后，在Wall细胞系及其匹配的肿瘤样本中发现了TP53的E273K突变。转录组分析分别在Wall细胞系，以及D17与D22细胞系中，鉴定出两种潜在的p53失活机制。此外，在D17与D22细胞系中观察到MET基因过表达，该现象可能介导MAPK/ERK通路的激活。综上，本研究完成了多株犬OSA细胞系的分子特征表征，可为后续潜在治疗靶点与关联生物标志物的研究提供数据基础。值得关注的是，Wall细胞系在构建过程中保留了TP53驱动突变，而该突变在多种人类癌症中均被报道为突变热点，因此该细胞系可作为极具价值的研究模型，推动人类与犬类的体外前瞻性研究。