BackgroundInvasive urothelial carcinoma (iUC) is a major cause of death in humans, and approximately 165,000 individuals succumb to this cancer annually worldwide. Comparative oncology using relevant animal models is necessary to improve our understanding of progression, diagnosis, and treatment of iUC. Companion canines are a preferred animal model of iUC due to spontaneous tumor development and similarity to human disease in terms of histopathology, metastatic behavior, and treatment response. However, the comprehensive molecular characterization of canine iUC is not well documented. In this study, we performed transcriptome analysis of tissue samples from canine iUC and normal bladders using an RNA sequencing (RNA-Seq) approach to identify key molecular pathways in canine iUC.MethodsTotal RNA was extracted from bladder tissues of 11 dogs with iUC and five healthy dogs, and RNA-Seq was conducted. Ingenuity Pathway Analysis (IPA) was used to assign differentially expressed genes to known upstream regulators and functional networks.ResultsDifferential gene expression analysis of the RNA-Seq data revealed 2531 differentially expressed genes, comprising 1007 upregulated and 1524 downregulated genes, in canine iUC. IPA revealed that the most activated upstream regulator was PTGER2 (encoding the prostaglandin E2 receptor EP2), which is consistent with the therapeutic efficiency of cyclooxygenase inhibitors in canine iUC. Similar to human iUC, canine iUC exhibited upregulated ERBB2 and downregulated TP53 pathways. Biological functions associated with cancer, cell proliferation, and leukocyte migration were predicted to be activated, while muscle functions were predicted to be inhibited, indicating muscle-invasive tumor property.ConclusionsOur data confirmed similarities in gene expression patterns between canine and human iUC and identified potential therapeutic targets (PTGER2, ERBB2, CCND1, Vegf, and EGFR), suggesting the value of naturally occurring canine iUC as a relevant animal model for human iUC.Electronic supplementary materialThe online version of this article (10.1186/s12885-018-4409-3) contains supplementary material, which is available to authorized users.

Exosomes are small extracellular vesicles released from almost all cell types, which play roles in cell-cell communication. Recent studies have suggested that microenvironmental crosstalk mediated by exosomes is an important factor in the escape of tumour cells from the anti-tumour immune system in human haematopoietic malignancies. Here, we conducted comprehensive analysis of the miRNA and protein profiles within the exosomes released from four canine lymphoid tumour cell lines as a model of human lymphoid tumours. The results showed that the major miRNAs and proteins extracted from the exosomes were similar among the four cell lines. However, the miRNA profiles differed among the exosomes of each cell line, which corresponded to the expression patterns of the parent cells. In the comparison of the amounts of miRNAs and proteins among the cell lines, those of three miRNAs (miR-151, miR-8908a-3p, and miR-486) and CD82 protein differed between exosomes derived from vincristine-sensitive and resistant cell lines. Further investigations are needed to elucidate the biological functions of the exosomal contents in the microenvironmental crosstalk of lymphoid tumours.

17Exosomes are small extracellular vesicles released from almost all cell types, 18 which play roles in cell-cell communication. Recent studies have suggested that 19 microenvironmental crosstalk mediated by exosomes is an important factor in the 20 escape of tumour cells from the anti-tumour immune system in human haematopoietic 21 malignancies. Here, we conducted comprehensive analysis of the miRNA and protein 22 profiles within the exosomes released from four canine lymphoid tumour cell lines as a 23 model of human lymphoid tumours. The results showed that the miRNAs and proteins 24 abundantly contained in exosomes were similar among the four cell lines. However, the 25 profiles of miRNA within exosomes differed among the cell lines and reflected the 26 expression pattern of miRNAs of the parent cells. In the comparison of the amounts of 27 miRNAs and proteins among the cell lines, those of three miRNAs (miR-151, 28 miR-8908a-3p, and miR-486) and CD82 protein differed between exosomes derived 29 from vincristine-sensitive and resistant cell lines. Further investigations are needed to 30 elucidate the biological functions of the exosomal contents in the microenvironmental 31 crosstalk of lymphoid tumours.32 3 33 Introduction 34 Exosomes are small extracellular vesicles released from almost all cell types, 35 including immune cells and tumour cells [1], as the intracellular endosome component. 36 Although exosomes were initially considered cellular waste, they have been shown to 37 contain various molecules from the original cells, including proteins, functional mRNAs 38 and miRNAs, and deliver these biological messages into the recipient cells [1,2]. To 39 date, it has also been reported that tumour cells release a number of exosomes and they 40 stimulate tumour cell growth and modify the immune cell response to promote tumour 41 progression and metastasis in several human tumors, including colorectal cancer [3], 42 breast cancer [4], melanoma [5], and pancreatic cancer [6]. Thus, the interaction 43 between tumour cell-derived exosomes and recipient cells in the microenvironment of 44 solid tumours is considered an important factor in tumour progression, metastasis, cell 45 survival, and escape from the anti-tumour immune system. 46 Exosomes have also been suggested to play important roles in the 47 microenvironmental crosstalk of human haematopoietic tumours, including leukaemia 48 and lymphoma [7,8]. It has been reported that exosomes derived from acute/chronic 49 myeloid leukaemia and lymphoma cells inactivate natural killer cells and suppress the 50 anti-tumour immune response [7-9]. In addition, exosomes have been reported to be 4 51 associated with drug resistance in these tumours [7]. For instance, it was reported that 52 exosomes derived from imatinib-resistant chronic leukaemia cells could confer 53 imatinib-resistance traits into sensitive cells by delivering miR-365 [10]. It was also 54 reported that exosomes derived from bone marrow stromal cells decreased the 55 sensitivity of acute lymphoblasti...

Histiocytic sarcoma (HS) is an incurable aggressive tumor, and no consensus has been made on the treatment due to its rare occurrence. Since dogs spontaneously develop the disease and several cell lines are available, they have been advocated as translational animal models. In the present study, therefore, we explored gene mutations and aberrant molecular pathways in canine HS by next generation sequencing to identify molecular targets for treatment. Whole exome sequencing and RNA-sequencing revealed gene mutations related to receptor tyrosine kinase pathways and activation of ERK1/2, PI3K-AKT, and STAT3 pathways. Analysis by quantitative PCR and immunohistochemistry revealed that fibroblast growth factor receptor 1 (FGFR1) is over-expressed. Moreover, activation of ERK and Akt signaling were confirmed in all HS cell lines, and FGFR1 inhibitors showed dose-dependent growth inhibitory effects in two of the twelve canine HS cell lines. The findings obtained in the present study indicated that ERK and Akt signaling were activated in canine HS and drugs targeting FGFR1 might be effective in part of the cases. The present study provides translational evidence that leads to establishment of novel therapeutic strategies targeting ERK and Akt signaling in HS patients.