Genomic Analysis of Canine Appendicular Osteosarcoma Metastases
In this study, analysis was done on matched normal, primary, and metastatic samples of canine appendicular osteosarcoma that were preserved by either formalin fixation or freezing. The frozen samples were analyzed for copy number aberrations, RNA expression, and somatic variants, using arrayCGH, RNA microarrays, and DNA sequencing data. Comparison of DNA ploidy and RNA expression between matched primary and metastatic samples showed few significant changes suggesting that most changes happen before metastasis. Matched primary and metastatic samples from the same patient shared more somatic variants with each other than with samples from the same group. The frozen and formalin fixed samples were compared to analyze the artifacts caused by formalin fixation. The results showed that formalin fixed samples had lower quality properties than their frozen counterparts. Despite this, the formalin fixed samples still retained many of the biological patterns present in their frozen counterparts.