Comparative oncology DNA sequencing of canine T cell lymphoma via human hotspot panel

Abstract

T-cell lymphoma (TCL) is an uncommon and aggressive form of human cancer. Lymphoma is the most common hematopoietic tumor in canines (companion animals), with TCL representing approximately 30% of diagnoses. Collectively, the canine is an appealing model for cancer research given the spontaneous occurrence of cancer, intact immune system, and phytogenetic proximity to humans. We sought to establish mutational congruence of the canine with known human TCL mutations in order to identify potential actionable oncogenic pathways. Following pathologic confirmation, DNA was sequenced in 16 canine TCL (cTCL) cases using a custom Human Cancer Hotspot Panel of 68 genes commonly mutated in human TCL. Sequencing identified 4,527,638 total reads with average length of 229 bases containing 346 unique variants and 1,474 total variants; each sample had an average of 92 variants. Among these, there were 258 germline and 32 somatic variants. Among the 32 somatic variants there were 8 missense variants, 1 splice junction variant and the remaining were intron or synonymous variants. A frequency of 4 somatic mutations per sample were noted with >7 mutations detected in MET, KDR, STK11 and BRAF. Expression of these associated proteins were also detected via Western blot analyses. In addition, Sanger sequencing confirmed three variants of high quality (MYC, MET, and TP53 missense mutation). Taken together, the mutational spectrum and protein analyses showed mutations in signaling pathways similar to human TCL and also identified novel mutations that may serve as drug targets as well as potential biomarkers.

Canine CD4+ T‐cell lymphoma identified by flow cytometry exhibits a consistent histomorphology and gene expression profile

“…The global gene expression pattern was consistent with downregulation of PTEN and upregulation of the PI3K/AKT and mTOR pathways. This finding supports previous studies that have identified mutations in PTEN in canine TCL . Variant analysis of RNA transcripts identified a silent single nucleotide polymorphism in the PTEN transcript in one of the six sequenced PTCL samples.…”

“…A recent study used a Human Cancer Hotspot Panel to identify potential tumour-associated mutations in canine PTCL. 36 MET, KDR, STK11, and BRAF were highly mutated and missense mutations were identified in MYC, TP53, and MET. In our study, a synonymous mutation in the promoter region of MYC and synonymous mutations in exons of KDR were present.…”

“…A recent study used a Human Cancer Hotspot Panel to identify potential tumour‐associated mutations in canine PTCL . MET, KDR, STK11 , and BRAF were highly mutated and missense mutations were identified in MYC, TP53 , and MET .…”

Activation of the Anaphase Promoting Complex reverses multiple drug resistant cancer

“…The canine model of cancer is considered an excellent model for human translation [66][67][68][69]. Thus, we employed companion canines recruited to the Western College of Veterinary Medicine at the University of Saskatchewan with treatment resistant lymphoma into our study to reveal the gene expression differences between tumors with variable treatment responsivenesses, as well as to determine the effects of metformin on cancer progression in these animals.…”

“…Our proximity to the largest Veterinary College in western Canada provided us an opportunity to obtain treatment resistant tumor samples representative of in vivo events as companion dogs present regularly to the oncology clinic for diagnosis and chemotherapy. Canine lymphoma is orthologous to non-Hodgkin lymphoma of B-and T-cells and has a relapsing-remitting course with a high incidence of terminal MDR transformation [33][34][35]. The superficial nature of the lymph node enlargements allows easy access to tumor sampling in a non-invasive manner.…”