Transcriptome of Two Canine Prostate Cancer Cells Treated With Toceranib Phosphate Reveals Distinct Antitumor Profiles Associated With the PDGFR Pathway

Abstract

Canine prostate cancer (PC) presents a poor antitumor response, usually late diagnosis and prognosis. Toceranib phosphate (TP) is a nonspecific inhibitor of receptor tyrosine kinases (RTKs), including vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and c-KIT. This study aimed to evaluate VEGFR2, PDGFR-β, and c-KIT protein expression in two established canine PC cell lines (PC1 and PC2) and the transcriptome profile of the cells after treatment with TP. Immunofluorescence (IF) analysis revealed VEGFR2 and PDGFR-β protein expression and the absence of c-KIT protein expression in both cell lines. After TP treatment, only the viability of PC1 cells decreased in a dose-dependent manner. Transcriptome and enrichment analyses of treated PC1 cells revealed 181 upregulated genes, which were related to decreased angiogenesis and cell proliferation. In addition, we found upregulated PDGFR-A, PDGFR-β, and PDGF-D expression in PC1 cells, and the upregulation of PDGFR-β was also observed in treated PC1 cells by qPCR. PC2 cells had fewer protein-protein interactions (PPIs), with 18 upregulated and 22 downregulated genes; the upregulated genes were involved in the regulation of parallel pathways and mechanisms related to proliferation, which could be associated with the resistance observed after treatment. The canine PC1 cell line but not the PC2 cell line showed decreased viability after treatment with TP, although both cell lines expressed PDGFR and VEGFR receptors. Further studies could explain the mechanism of resistance in PC2 cells and provide a basis for personalized treatment for dogs with PC.

Expression and prognostic significance of vascular endothelial growth factor‐A (VEGF‐A) and its receptor in canine prostate cancer

“…Recently, our research group determined the positive expression levels of VEGFR‐2 in two canine PC cell lines and evaluated the cell line transcriptome after treatment with toceranib 28 . Toceranib is a multi‐kinase inhibitor that blocks the transcription of several receptors, including c‐KIT, platelet‐derived growth factor receptor‐β, and VEGFR‐2 28 .…”

“…Recently, our research group determined the positive expression levels of VEGFR‐2 in two canine PC cell lines and evaluated the cell line transcriptome after treatment with toceranib 28 . Toceranib is a multi‐kinase inhibitor that blocks the transcription of several receptors, including c‐KIT, platelet‐derived growth factor receptor‐β, and VEGFR‐2 28 . PC1 cell lines treated with toceranib showed lower gene expression levels of VEGFR‐2 , demonstrating the efficacy of toceranib in inhibiting the VEGFR‐2 gene in canine PC.…”

An Update on Molecular Pathways Regulating Vasculogenic Mimicry in Human Osteosarcoma and Their Role in Canine Oncology

“…An extensive knowledge concerning PDGF/PDGFR axis is available in veterinary literature. This molecular axis has been investigated as endothelial marker ( 91 ), in wound healing ( 92 ), spontaneous canine astrocytoma ( 93 ), fibrosarcoma ( 94 ), squamous cell carcinoma ( 95 ), lymphoma ( 96 ), prostate cancer ( 97 ), hemangioma and hemangiosarcoma ( 98 ), melanoma ( 99 ), mast cell tumors ( 100 ), hepatocellular carcinoma ( 101 ), mammary tumors ( 102 ), and nervous system tumors ( 103 , 104 ).…”

Evaluation of the therapeutic potential of masitinib and expression of its specific targets c‐Kit, PDGFR‐α, PDGFR‐β, and Lyn in canine prostate cancer cell lines

“…2,5,6 Therefore, the evaluation of new treatment strategies, such as tyrosine kinase inhibitors (TKIs) targeting specific tyrosine kinases (TKs) deregulated in cancer, is a promising approach. [7][8][9] TKs are enzymes, which selectively phosphorylate tyrosine residue in target proteins. These proteins in turn regulate the transcription of various genes intranuclearly, which, among others, stimulate angiogenesis, cell division, apoptosis, and cell differentiation.…”