Contrast-enhanced ultrasonography characteristics of intrathoracic mass lesions in 36 dogs and 24 cats.

Contrast-enhanced ultrasonography (CEUS) is increasingly available for veterinary patients, however limited studies describe the use of this method for characterizing intrathoracic mass lesions. The aim of this prospective, observational study was to describe CEUS enhancement patterns for intrathoracic mass lesions in a sample of cats and dogs. Sixty patients (36 dogs, 24 cats) were included. Standardized CEUS examinations were performed for 41 pulmonary masses (68%) and 19 mediastinal masses (32%). Final diagnosis was based on cytology and/or histopathology. Absolute time to enhancement (TTE) values were recorded for the intrathoracic mass lesions and spleen. The spleen was used as a reference parenchymal organ to calculate relative TTE (rTTE) values. Absolute TTE of the spleen and intrathoracic mass lesions differed for dogs and cats (P = 0.001). The rTTE values significantly differed between lesions of neoplastic versus non-neoplastic origin (P = 0.004). The majority of neoplastic pulmonary masses were supplied by bronchial arteries (63%), while most nonneoplastic pulmonary masses were supplied by pulmonary arteries (78%). The sensitivity and specificity for detecting pulmonary neoplastic masses with rTTE were 63% and 78%, respectively. Enhancement patterns for mediastinal thymomas and lymphomas significantly differed (P = 0.002). Thymomas enhanced heterogeneously in a centripetal pattern (86%), whereas lymphomas typically enhanced uniformly in a centrifugal pattern (75%). Findings indicated that CEUS is a feasible method for characterizing intrathoracic mass lesions in dogs and cats, however, the diagnostic sensitivity for detecting neoplastic pulmonary masses was low.

Alternative lengthening of telomeres does exist in various canine sarcomas.

Alternative lengthening of telomeres (ALT) is a telomere maintenance mechanism (TMM) found in some human tumors such as sarcomas. Canine tumors are not characterized for ALT and the study aim was to identify if the ALT phenotype exists in canine sarcomas. Sixty-four canine sarcoma samples (20 snap-frozen, 44 FFPE) as well as six canine sarcoma cell lines were screened for ALT by C-circle assay. ALT was further evaluated by measuring telomere length via qPCR and telomere restriction-fragments including pulsed-field electrophoresis. ALT-associated proteins were validated by immunohistochemistry. Further, telomerase activity (TA) and gene expression were analyzed by TRAP and qPCR. DNA from 20 human neuroblastomas and 8 sarcoma cell lines served as comparative controls. ALT was detected in 9.4% (6/64) canine sarcomas including aggressive subtypes as hemangiosarcoma, osteosarcoma, and histiocytic sarcoma. C-circle levels were comparable with human ALT-positive controls. All ALT tumors demonstrated loss of ATRX expression and 5/6 showed strong p53 expression. TA was detected in 93% (14/15) snap-frozen samples including a sarcoma with ALT activity. This tumor showed long heterogeneous telomeres, and a high level of colocalization of DAXX with telomeres. One sarcoma was ALT and TA negative. All canine and human sarcoma cell lines were ALT negative. In this study, we demonstrated that canine sarcomas use ALT. As in humans, ALT was identified in aggressive sarcomas subtypes and coexisted with TA in one tumor. Overall, canine sarcomas seem to share many similarities with their human counterparts and appear an attractive model for comparative telomere research. © 2016 Wiley Periodicals, Inc.

Canine and human sarcomas exhibit predominant FGFR1 expression and impaired viability after inhibition of signaling.

Fibroblast growth factor receptors (FGFRs) are important in malignant progression of several human epithelial tumors. However, little is known about FGFRs in canine or human soft tissue sarcomas. Thus, our aim was to investigate expression of FGFRs and their involvement in cell survival in sarcomas of both species. FGFR1-4 and FGFRL1 transcripts as well as IIIb/IIIc splice variants of FGFR1-3 were evaluated in 3 canine- and 6 human sarcoma cell lines and 19 spontaneous canine sarcomas by SYBRqPCR. FGFR1 protein expression was assessed by immunohistochemistry. Growth inhibitory effects of FGFR1 inhibitor PD166866 and dominant negative recombinant FGFR adenoviral expression constructs (dnFGFR) on tumor cell lines were analyzed. Profiling of multiple FGFR transcripts detected comparable co-expression in most of human and canine sarcoma cell lines and canine tumor specimens. This indicates existence of closely related regulation mechanisms for FGFR expression in sarcomas of both species. FGFR1 with splice variant IIIc was consistently expressed with highest transcript levels. In 88% of the spontaneous tumor samples a heterogeneous FGFR1 protein expression was observed. Significant growth inhibition and cell death was seen after infection with dnFGFR1 in canine and human sarcoma cells, but not with dnFGFR3 and 4. PD166866 showed selective cytotoxicity with IC50 values between 12.1 and 26.4 µM. FGFR1 inhibition blocked ligand-induced tyrosine phosphorylation of ERK1/2 mitogen-activated protein kinase isoforms. This study emphasizes the important role FGFR1, especially splice variant IIIc, likely plays in sarcomas. Inhibitory small molecules could be of potential use for targeted therapy in aggressive sarcomas of both species.

Alternative Lengthening of Telomeres Is Rare in Canine Histiocytic Sarcoma.

Cancer cells activate telomere maintenance mechanisms (TMMs) to overcome senescence and thus are targets for TMM-specific therapies. Telomerase-independent alternative lengthening of telomeres (ALT) is frequently utilized as a TMM in human sarcoma subtypes. Histiocytic sarcoma (HS) is a rare but aggressive tumor of hematopoietic origin with unknown ALT incidence in humans. ALT has been identified in canine HS, a tumor type comparable to human HS that occurs with high rates in certain canine breeds such as Bernese mountain dogs (BMDs). This retrospective study characterized the frequency of ALT in BMD and non-BMD patients diagnosed with HS as surrogates for humans. Formalin-fixed paraffin-embedded tumor samples from 63 dogs at two centers, including 47 BMDs, were evaluated for their ALT activity and relative telomere content (TC) using a radiolabel C-circle assay (CCA). Known ALT-positive samples served as controls. CCA-positive cases were validated via FISH. Two BMD samples showed ALT activity of 1-14% compared to controls. All other samples were ALT-negative. The TC did not correlate with the CCA results. ALT positivity was validated by the appearance of ultrabright telomere foci. Low ALT activity was present in 4% of BMDs with HS and therefore does not appear to be a common target for therapeutic approaches but can have diagnostic value.

Histopathological findings in the uteri and ovaries of clinically healthy cats presented for routine spaying.

OBJECTIVES: The aim of this study was to assess the histopathological findings in the uteri and ovaries from clinically healthy queens presented for elective spaying. METHODS: Ovaries and distal uterine horns or complete uteri from 106 female cats were evaluated for pathological alterations. RESULTS: Pathological alterations of the uterus and/or ovaries were evident in 29 cats; of these, corpora lutea were present on the ovaries of 15 cats. Ovarian cysts were found in 15 cats and were classified as cysts of the Wolffian or Muellerian ducts (n = 4), follicular cysts (n = 4), luteal cysts (n = 1), cystic rete ovarii (n = 2), combinations of different cysts (n = 2) and non-classifiable cysts (n = 2). In 21/106 cats, cystic endometrial hyperplasia (CEH) was present. The incidence of CEH increased with the age of the cat. Six cats had purulent endometritis with or without distension of the uterine lumen. Hyperplastic lesions of the endometrium were detected in two cats. In one cat, a uterine horn malformation with duplication of one uterine horn lumen was diagnosed. CONCLUSIONS AND RELEVANCE: Whereas the majority of ovarian cysts and slight-to-moderate CEH are unlikely to interfere with an animal's wellbeing, endometritis must be considered a serious health problem that requires veterinary attention.

Prevalence and potentially prognostic value of C-circles associated with alternative lengthening of telomeres in canine appendicular osteosarcoma.

Alternative lengthening of telomeres (ALT) is a telomerase-independent telomere maintenance mechanism (TMM) with high prevalence in human osteosarcomas but remains unknown in canine osteosarcomas. The aim of this study was to evaluate the prevalence of ALT by detection of extra-chromosomal circles of telomeric DNA and to assess clinical outcome in canine patients with spontaneous occurring appendicular osteosarcoma. Fifty dogs with histopathological confirmed osteosarcomas were included into this study. Medical records were retrospectively analysed for patient characteristics, oncologic therapy and survival. DNA was isolated from archived FFPE tumour tissue specimens and applied for C- and G-circle assay (CCA and GCA) and for telomeric content (TC) measurement with radiolabeled probes. ALT activity was detected for 10 of 50 (20%) cases by CCA. Four CCA positive cases were detected even with input DNA below 1 ng and demonstrated the high sensitivity of CCA for canine tumours. G-circles and TC were not suitable to distinguish CCA positive and negative cases. CCA-status showed an association with male gender and Rottweiler breed. Dogs with CCA positive osteosarcomas had shorter overall survival times than patients with CCA-tumours and CCA-status was a significant prognostic factor besides treatment in the Cox proportional hazard model. These findings make canine osteosarcomas an interesting model for comparative TMM research, but future studies are warranted to investigate if CCA-status can serve as novel prognostic marker.

Chemotherapy in canine acute megakaryoblastic leukemia: a case report and review of the literature.

Acute myeloid leukemia (AML) in dogs is a rare disease with poor prognosis. In most subjects, palliative treatment or euthanasia is performed. A 3.5-year-old male castrated labrador with AML-M7, which was treated with induction polychemotherapy (8 cycles) using vincristine (0.5 mg/m(2)/cycle), daunorubicin (20 mg/m(2)/cycle), cytosine arabinoside (ARA-C, 100 mg/m(2)/cycle) and prednisolone (1 mg/kg/day) is reported. Treatment was well tolerated and complete remission was achieved. Postinduction chemotherapy consisted of ARA-C, daunorubicin and prednisolone. After 3, 5 and 18 months, the subject relapsed. Each relapse was treated with ARA-C (up to 1,000 mg/m(2)) and etoposide or daunorubicin. Again, no severe side-effects occurred and the disease was controlled, with 37 chemotherapy-cycles (ARA-C, 3 x 1,000 mg/m(2)/cycle), for 24 months. Based on a literature-search, this is the first report documenting a long-term response of canine AML, probably resulting from the high-dose ARA-C. Clinical trials using high-dose ARA-C are now required to confirm antileukemic efficacy in canine leukemias.

Spontaneous ovulation in cats-Uterine findings and correlations with animal weight and age.

Cats are considered induced ovulating animals but ovulations occur in the absence of mating (i.e., spontaneous ovulations). Factors that stimulate such ovulations remain largely unknown. In this study, ovaries and uterine horn segments from 89 post-pubertal queens presented for ovariectomy were evaluated morphologically and histologically. It was hypothesized that corpora lutea (CL) are present in non-pregnant cats and can be associated with cystic endometrial hyperplasia (CEH). Cats were assigned to three age groups (7-12 months, n = 32; 13-24 months, n = 26 and ≥ 24 months, n = 31) and three weight groups (2.1-2.8 kg, n = 28; > 2.8-3.3 kg, n = 32 and > 3.3 kg, n = 29). Uterine horn diameter and thickness of the endometrium and myometrium were determined. Corpora lutea were detected in 39.3% of the cats and presence did not differ between age groups. The percentage of queens with CL increased with bodyweight (2.1-2.8 kg: 14.3%; > 2.8-3.3 kg: 37.5%, > 3.3 kg: 65.5%; P < 0.01). In cats with CL, the thickness of all layers of the uterus were greater than in cats without CL (P < 0.05). Of the cats, 22.5% had CEH but there was no difference between cats without and with CL. The percentage of CEH increased with age (P < 0.001) but did not differ between weight groups. In conclusion, ovulations occurred in the absence of mating in approximately one third of all queens.

Canine oral primary melanoma cells exhibit shift to mesenchymal phenotype and phagocytic behaviour.

Canine oral malignant melanoma (COMM) is a potentially lethal cancer disease. We established primary cell lines from mostly amelanotic primary COMM and metastases and assessed lesions and derived cells for Melan A, PNL2 and CD146 expression. Then, migration and invasion of CD146-enriched vs -depleted COMM cells were analysed. Epithelial-to-mesenchymal transition (EMT) was addressed by Vimentin-staining and MMP2/MMP9 zymography. Phagocytic behaviour was analysed by histopathological examination and phagocytosis assay. While Melan A- and PNL2-staining yielded inconsistent data, 100% of COMM sections and primary cells showed CD146 expression, suggesting that this protein may serve as a prognostic marker. An overall correlation between CD146-expression and migration/invasion was not observed. All primary cell lines consistently expressed Vimentin and secreted biologically active MMP2, indicating that they had undergone EMT. Importantly, COMM sections exhibited cell-in-cell structures, and all primary cell lines exhibited phagocytic activity, supporting the concept that cell cannibalism may have a role in COMM progression.

The JAK2/STAT5 signaling pathway as a potential therapeutic target in canine mastocytoma.

BACKGROUND: Mastocytoma are frequently diagnosed cutaneous neoplasms in dogs. In non-resectable mastocytoma patients, novel targeted drugs are often applied. The transcription factor STAT5 has been implicated in the survival of human neoplastic mast cells (MC). Our study evaluated the JAK2/STAT5 pathway as a novel target in canine mastocytoma. MATERIALS AND METHODS: We employed inhibitors of JAK2 (R763, TG101348, AZD1480, ruxolitinib) and STAT5 (pimozide, piceatannol) and evaluated their effects on 2 mastocytoma cell lines, C2 and NI-1. RESULTS: Activated JAK2 and STAT5 were detected in both cell lines. The drugs applied were found to inhibit proliferation and survival in these cells with the following rank-order of potency: R763 > TG101348 > AZD1480 > pimozide > ruxolitinib > piceatannol. Moreover, synergistic anti-neoplastic effects were obtained by combining pimozide with KIT-targeting drugs (toceranib, masitinib, nilotinib, midostaurin) in NI-1 cells. CONCLUSION: The JAK2/STAT5 pathway is a novel potential target of therapy in canine mastocytoma.

Pancreatic rupture in four cats with high-rise syndrome.

Pancreatic trauma and rupture are rare after feline high-rise syndrome; however, should it happen, pancreatic enzymes will leak into the abdominal cavity and may cause pancreatic autodigestion and fatty tissue saponification. If not diagnosed and treated, it can ultimately lead to multiorgan failure and death. In this case series, 700 records of high-rise syndrome cats that presented between April 2001 and May 2006 were analysed, and four cats with pancreatic rupture were identified. Clinical signs, diagnosis using ultrasonography and lipase activity in blood and abdominal effusion, and treatment modalities are reported. Three cats underwent surgical abdominal exploration, one cat was euthanased. Rupture of the left pancreatic limb was confirmed in all cases. Two of the operated cats survived to date. High-rise syndrome can lead to abdominal trauma, including pancreatic rupture. A prompt diagnosis and surgical treatment should be considered.

Phylogenetic discordance of human and canine carcinoembryonic antigen (CEA, CEACAM) families, but striking identity of the CEA receptors will impact comparative oncology studies.

Comparative oncology aims at speeding up developments for both, human and companion animal cancer patients. Following this line, carcinoembryonic antigen (CEA, CEACAM5) could be a therapeutic target not only for human but also for canine (Canis lupus familiaris; dog) patients. CEACAM5 interacts with CEA-receptor (CEAR) in the cytoplasm of human cancer cells. Our aim was, therefore, to phylogenetically verify the antigenic relationship of CEACAM molecules and CEAR in human and canine cancer.Anti-human CEACAM5 antibody Col-1, previously being applied for cancer diagnosis in dogs, immunohistochemically reacted to 23 out of 30 canine mammary cancer samples. In immunoblot analyses Col-1 specifically detected human CEACAM5 at 180 kDa in human colon cancer cells HT29, and the canine antigen at 60, 120, or 180 kDa in CF33 and CF41 mammary carcinoma cells as well as in spontaneous mammary tumors. While according to phylogenicity canine CEACAM1 molecules should be most closely related to human CEACAM5, Col-1 did not react with canine CEACAM1, -23, -24, -25, -28 or -30 transfected to canine TLM-1 cells. By flow cytometry the Col-1 target molecule was localized intracellularly in canine CF33 and CF41 cells, in contrast to membranous and cytoplasmic expression of human CEACAM5 in HT29. Col-1 incubation had neither effect on canine nor human cancer cell proliferation. Yet, Col-1 treatment decreased AKT-phosphorylation in canine CF33 cells possibly suggestive of anti-apoptotic function, whereas Col-1 increased AKT-phosphorylation in human HT29 cells. We report further a 99% amino acid similarity of human and canine CEA receptor (CEAR) within the phylogenetic tree. CEAR could be detected in four canine cancer cell lines by immunoblot and intracellularly in 10 out of 10 mammary cancer specimens from dog by immunohistochemistry. Whether the specific canine Col-1 target molecule may as functional analogue to human CEACAM5 act as ligand to canine CEAR, remains to be defined. This study demonstrates the limitations of comparative oncology due to the complex functional evolution of the different CEACAM molecules in humans versus dogs. In contrast, CEAR may be a comprehensive interspecies target for novel cancer therapeutics.

Synovial cyst of the fifth digit in a cat.

A synovial cyst of the fifth digit of the left forelimb in a 15-year-old cat was diagnosed. Radiographs showed severe osteoarthritis of the interphalangeal and metacarpophalangeal joints with soft tissue swelling. An ultrasound examination of the digit revealed a cystic structure. Following amputation of the digit, the cyst recurred 3 months later palmar to the carpus and metacarpus. The aetiology of synovial cysts is discussed.

Radiation therapy communication: equine hemangioma.

A 13-month-old Standardbred Colt had a recurrent hemangioma at the level of the coronary band. Multiple excisions had led to a nonhealing skin and hoof defect. Using 14 MV electrons, a total dose of 36 Gy was administered, given as six fractions of 6 Gy twice a week. Wound healing by second intention was achieved over the next 4 months and the colt began race training 6 months after the end of therapy. Twenty months later the colt is sound and there is no evidence of tumor recurrence.

Fatal infection of a pet monkey with Human herpesvirus.

Concerns have been raised about pet monkeys as a potential threat to humans. We report the opposite situation, a danger to pets that arises from humans. Similar to herpesvirus B (Cercopithecine herpesvirus 1), which endangers humans but not its host species, Human herpesvirus 1 can act as a "killer virus" when crossing the species barrier to New World monkeys.