Genomic and Transcriptomic Characterization of Canine Osteosarcoma Cell Lines: A Valuable Resource in Translational Medicine

Abstract

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.

The mitotic regulator polo‐like kinase 1 as a potential therapeutic target for c‐Myc‐overexpressing canine osteosarcomas

“…44 RNA sequencing analyses from a previous study showed an aberrant expression of both MYC and PLK1 in two cOSA cell lines (D17 and D22) although no mutations were detected in WES analysis. 3 Similarly, two recent studies reported an aberrant gene expression of MYC in cOSA samples. 45,46 In hOSA cell lines, c-Myc overexpression is known to promote cell invasion via MAPK/ERK signalling.…”

“…In hOSA, c‐Myc is frequently overexpressed and correlated with the development of metastases and a poor prognosis 12,15–17 . Although aberrant activation of c‐Myc pathway genes has been previously reported, 3,13 only recently MYC activation was correlated with a short disease‐free interval in cOSA 14 …”

“…In a recent RNA‐seq study, both PLK1 and MYC oncogenes were found overexpressed in two well‐established cOSA cell lines, suggesting a potential implication of this signalling axis in this tumour 3 . BI 2536, was the first selective PLK1 inhibitor able to promote mitotic arrest and apoptosis in MG‐63 human OSA cell line 22 and xenografts models 23 .…”

The genomic landscape of canine osteosarcoma cell lines reveals conserved structural complexity and pathway alterations

“…Established cell lines have long been used to study tumor biology and response to targeted therapies. More recently, single gene evaluation and WES have been used to chart the mutational landscape of canine cancer cell lines, providing a crucial resource for prospective studies [1,[53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70]. The WGS data reported here identified many simple somatic mutations previously…”

Immunohistochemical Characterisation of GLUT1, MMP3 and NRF2 in Osteosarcoma

“…Canine OSA remains challenging to treat and carries a poor prognosis due to the very aggressive and metastatic nature of the tumors. Given how common OSA is in dogs and likely genetic contribution to OSA in large breeds, we (16) and others (25,(41)(42)(43) have sought to extend understanding of the molecular determinants of OSA in dogs and to compare these results to those obtain from OSA from people.…”