Triple-negative mammary carcinoma in two male dogs.

Triple-negative tumors are characterized immunohistochemically by the absence of positivity to sex hormone receptors and to human epidermal growth factor receptor 2. Additionally, they are differentiated into basal-like and non-basal (or null) subtypes, based on the presence of basal cytokeratin expression (CK5/6, 14, and17). Triple-negative subtypes are yet to be characterized in male dogs, to our knowledge. We report herein the clinical and pathologic findings and molecular characterization of carcinoma in the mammary glands of 2 male dogs. Case 1 was diagnosed as a grade II tubulopapillary carcinoma; case 2 was diagnosed as a grade II carcinoma in a mixed tumor. The tumors were characterized phenotypically as triple-negative basal and triple-negative non-basal, respectively.

Tumor-associated macrophage is correlated with survival and SOCS protein expression in canine mammary carcinoma / Correlação do infiltrado macrofágico com a sobrevida e a expressão da proteína SOCS no carcinoma mamário canino

The inflammatory infiltrate in the tumor microenvironment, particularly in mammary tumors, has aroused great interest in oncology, to play different roles in the progression or tumor regression dependent on the types and cell subsets involved. The present study aimed to evaluate (1) the occurrence and intensity of macrophage infiltration in the mammary carcinoma microenvironment, (2) the expression of SOCS1 and SOCS3 proteins in tumor associated macrophages, (3) any association between these parameters and tumor development, as well as survival rates in female dogs. Twenty-two female dogs diagnosed as carcinoma arising in a mixed tumor (CMT) by histopathology were divided into two groups following mastectomy: dogs without metastasis (CMT(-)=11) and those with metastasis (CMT(+)=11). The following parameters were analyzed: tumor size, lymph node metastasis, clinical stage, histological grade, distribution and intensity of inflammatory infiltrate, tumor macrophage quantification by immunohistochemical analysis of SOCS1 and SOCS3 expression, and immunophenotyping of peripheral blood leukocytes by flow cytometry. Dogs with the higher proportions of macrophages in the inflammatory infiltrate (≥400/tumor) also had higher survival rates in comparison with dogs with less macrophages. Immunostaining revealed higher proportions of SOCS3-positive macrophages in dogs without lymph node metastasis, while SOCS1-positive macrophages were predominant in dogs with metastasis (p<0.05). Multivariate analysis found associations between survival rate and clinical staging (p=0.025), histological grade (p=0.007), and the expression of MHC-CI in circulating monocytes (p=0.018). Higher SOCS3 expression in activated macrophages within the inflammatory infiltrate were considered indicative of an antitumor immune response, improved clinicopathological parameters and longer survival, whereas SOCS1-related activation was associated with tumor progression, metastasis development and reduced survival in female dogs with mammary carcinomas.(AU)

O infiltrado inflamatório no microambiente tumoral, particularmente nos tumores mamários, tem despertado grande interesse na oncologia, por desempenhar diferentes funções na progressão ou regressão tumoral, dependendo dos tipos e subtipos celulares envolvidos. O presente estudo teve como objetivo avaliar: (1) a ocorrência e a intensidade do infiltrado macrofágico no microambiente do carcinoma mamário; (2) a expressão das proteínas SOCS1 e SOCS3 nos macrófagos associados ao tumor; (3) qualquer associação relacionada ao prognóstico entre estes parâmetros e o desenvolvimento tumoral, assim como a taxa de sobrevida. Vinte e duas cadelas diagnosticadas com carcinoma em tumor misto (CTM) por exame histopatológico foram divididas em dois grupos após a mastectomia: cadelas sem metástase (CTM(-)=11) e cadelas com metástase (CTM(+)=11). Foram analisados os seguintes parâmetros: tamanho do tumor, metástase para linfonodo, estadiamento clínico, grau histológico, distribuição e intensidade do infiltrado inflamatório, quantificação dos macrófagos tumorais por análise imuno-histoquímica da expressão de SOCS1 e SOCS3, e imunofenotipagem dos leucócitos (monócitos e linfócitos) do sangue periférico por citometria de fluxo. Cadelas que apresentavam maiores proporções de macrófagos no infiltrado inflamatório (≥400/tumor) também tiveram maior taxa de sobrevida em comparação àquelas com menos macrófagos. A imunomarcação revelou maiores proporções de macrófagos SOCS3-positivos em cães sem metástase para linfonodo, enquanto que macrófagos SOCS1-positivos foram predominantes naqueles com metástase (p<0,05). A análise multivariada identificou associações entre a taxa de sobrevida e o estadiamento clínico (p=0,025), grau histológico (p=0,007) e a expressão de MHC-CI em monócitos circulantes (p=0,018). A maior expressão de SOCS3 nos macrófagos ativados foi considerada indicativa de uma resposta imune antitumoral, melhores parâmetros clínicos e maior taxa de sobrevida, ao passo que a ativação relacionada com SOCS1 foi associada à progressão tumoral, desenvolvimento de metástase e redução na taxa de sobrevida em cadelas com carcinoma mamário.(AU)

Multicentric lymphoma in buffaloes in the Amazon region, Brazil.

BACKGROUND: The presence of lymphoma in buffaloes was first reported in India in the 1960s. The disease is similar to Enzootic Bovine Leucosis (EBL) caused by Bovine leukemia virus (BLV) in cattle; however, according to our results and those of other studies, the etiology of these lymphomas in buffalo do not appear to be associated with BLV. The objectives of this study are to describe four cases of the disease in buffaloes belonging to the same herd in the Amazon region of Brazil and to perform a clinical-anatomopathological, immunohistochemical, and etiological study of the lymphomas. RESULTS: Over a period of ten years, four buffaloes were observed presenting progressive weight loss, swelling of peripheral lymph nodes, and nodules in the subcutaneous tissue. Upon necropsy, whitish-colored tumor masses were observed in the form of nodules in the subcutaneous tissue, along with miliary nodules on the serosal surfaces of abdominal and thoracic organs and tumors in lymph nodes and other organs. Neoplastic lymphocyte proliferation was observed through histopathology. An immunohistochemical study revealed that the neoplasias were formed by proliferation of predominantly B lymphocytes. The presence of BLV genome was not detected in the lymphomas when using the real-time PCR technique, nor was it detected through immunohistochemical staining using monoclonal antibodies against two viral proteins. Bovine herpesvirus 6 was not detected in the tumors. However, Bovine immunodeficiency virus (BIV) was detected in samples of lymphoma and in the lymph nodes and kidneys of one of the animals. CONCLUSIONS: The occurrence of lymphoma in buffaloes is reported for the first time in Brazil and is characterized by B-cell multicentric lymphoma. The etiology of the disease does not appear to be associated with BLV; however, the detection of BIV in samples of lymphoma from one sick animal deserves further study, considering the oncogenic potential of this virus.

Evaluation of prognostic factors and survival rates in malignant feline mammary gland neoplasms.

OBJECTIVES: The aim of the study was to investigate prognostic factors in feline mammary gland neoplasms, correlating them with overall survival (OS). METHODS: Fifty-six primary malignant mammary gland neoplasms and 16 metastatic lymph nodes from 37 female cats were analyzed. Clinical staging, histologic type and grade, and immunohistochemistry for Ki-67, progesterone and estrogen receptor, human epidermal growth factor receptor type 2 (HER-2), cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) were evaluated. Follow-up was performed in order to correlate prognostic factors with OS. RESULTS: Lymph node metastasis was found in 35% of cases. Clinical stage III, tubulopapillary carcinomas and histologic grade II cases prevailed in the study. Most neoplasms were positive for hormonal receptors, negative for HER-2 overexpression and presented VEGF overexpression. Immunoreactivity for Ki-67 (P = 0.046) and COX-2 (P = 0.007) was higher in metastases than in primary tumors. COX-2 (P = 0.089), HER-2 (P = 0.012) and histologic grade (P = 0.080) were correlated with OS. CONCLUSIONS AND RELEVANCE: The data suggest that inhibition of ovarian hormones and COX-2 may represent a therapeutic option for malignant feline mammary gland neoplasms. When evaluating disease progression, COX-2 scores and Ki-67 index should be analyzed in primary tumors and metastases. Histologic grade, HER-2 status and COX-2 scores were found to have a direct influence on OS. Prognostic factors allow for a better understanding of disease outcome in a condition that is characterized by a poor prognosis. The present work highlights the need for further studies on endocrine therapy and COX-2 inhibitors, which could influence OS.

Malignant peripheral nerve sheath tumour in a sow.

Nodular lung lesions in swine are frequently due to abscesses or granulomatous pneumonia. Although tumours are rarely reported in modern pig farming, they should be considered as a differential diagnosis when nodular lung lesions are found. A first-parity sow exhibiting respiratory signs was euthanized. Several whitish firm nodules, not encapsulated, ranging in diameter from 0.5 to 5 cm were present in all lung lobes. Microscopically, the nodules were composed of dense neoplastic cells, mainly in Antoni types A and B patterns, infiltrative and with development of emboli. All neoplastic cells stained positively by immunohistochemistry for vimentin and S-100 protein, with variable immunostaining for glial fibrillary acidic protein and stained negative for cytokeratin. Based on the gross, histological and immunohistochemical features, the tumor was diagnosed as malignant peripheral nerve sheath tumour.

Canine low-grade intra-orbital myxosarcoma: case report.

OBJECTIVE: The aim of this study was to evaluate important clinical, morphological, histopathological, histochemical, and immunohistochemical characteristics in order to establish the diagnosis and prognosis of a low-grade intra-orbital myxosarcoma. ANIMAL STUDIED: A mongrel dog presented a 2-year history of a neoplastic mass behind the right eye. RESULTS: The neoplasm presented a mesenchymal spindle and stellate cell proliferation with an abundant myxoid matrix, moderate anisocariosis, and a low mitotic index. It stained positive for vimentin, moderately positive for periodic acid-Schiff, and negative for Gomori trichrome stain and α-smooth muscle actin. CONCLUSIONS: One year following surgical excision, the patient remains disease free. The histological findings established a diagnosis of a rare canine intra-orbital low-grade myxosarcoma.

Proteinase-activated receptor 2 blockade impairs CCL11- or allergen-induced eosinophil recruitment in experimental pleurisy.

Although proteinase-activated receptor (PAR)-2 has been implicated in inflammatory diseases, its role in regulating eosinophil recruitment in response to chemoattractants remains unclear. Here, we investigated the role of PAR-2 and PAR-2-activating Mast Cell (MC) tryptase on chemokine C-C motif ligand (CCL)11- and antigen-induced eosinophil recruitment to the pleural cavity of BALB/c mice. The PAR-2-activating peptide H-Ser-Leu-Ile-Gly-Arg-Leu-NH2 (SLIGRL-NH2) induced eosinophil recruitment whereas PAR-2 blockade inhibited ovalbumin (OVA)- or CCL11-induced eosinophil recruitment. Moreover, OVA and CCL11 induced PAR-2 expression in pleural leukocytes, and the MC tryptase inhibitor APC 366 ([N-(1-hydroxy-2-napthoyl)-l-arginyl-l-prolinamide hydrochloride]) abolished CCL11-induced eosinophil recruitment. These results suggest a pro inflammatory effect of PAR-2 and support a role for MC tryptase mediating eosinophil migration via PAR-2 signaling. Taken together, our results suggest that PAR-2 activation through endogenous MC tryptase activity could be required, at least partially, to mediate CCL11-induced eosinophil migration.

Versican expression in myoepithelial cells from carcinomas in canine mixed mammary tumors.

The matrix of canine mixed mammary tumors (CMMTs) consists of proliferating spindle cells of possible myoepithelial origin, as well as myxomatous tissue, cartilage matrix and/or bone. Among the multiple components of this tumor extracellular matrix, versican probably plays a prominent role due to its importance in tumor progression, cell proliferation and differentiation. However, there are few data related to a possible association between versican expression and the state of myoepithelial cell differentiation in CMMTs. Using immunohistochemistry and histochemistry, the objective of this study was to evaluate the expression of versican, sulfated proteoglycans and mucopolysaccharides in myoepithelial cells at different stages of differentiation and to explore a potential relationship with p63 and α-smooth muscle actin (SMA) expression. A significant difference in versican expression was observed among the different stages of myoepithelial cell differentiation with an inverse correlation between versican and p63/SMA expression. These results suggest that at an early stage of proliferation, myoepithelial cells acquire a phenotype consistent with a role in chondrogenesis. Moreover, myoepithelial cells showed an affinity for safranin and periodic acid-Schiff staining at different stages of proliferation supporting the myoepithelial origin of spindle cells from CMMTs.

Mast cell tryptase induces eosinophil recruitment in the pleural cavity of mice via proteinase-activated receptor 2.

Proteinase-activated receptor (PAR) 2 has been implicated in eosinophil migration. Mast cell (MC) tryptase has been similarly implicated in allergic diseases through the activation of PAR-2, but the role of this receptor in MC tryptase-induced inflammation is not well elucidated. This study aims to investigate the ability of MC tryptase or PAR-2 activating peptide (SLIGRL-NH2) to induce eosinophil recruitment to the pleural cavity of mice. Mast cell tryptase-injected mice were pretreated with PAR-2 antagonist ENMD-1068. Mice injected with SLIGRL-NH2 were pretreated with mast cell tryptase inhibitor APC 366, and eosinophil migration into the pleural cavity and PAR-2 expression was analyzed after 24 or 48 h. SLIGRL-NH2-induced eosinophil recruitment was inhibited by APC 366, and MC tryptase-induced eosinophil recruitment was abolished by ENMD-1068. MC tryptase induced PAR-2 expression on pleural eosinophils. Our results demonstrate a key role for PAR-2 in mediating eosinophil recruitment in MC tryptase-induced pleurisy in mice. The ability of MC tryptase to inducing PAR-2 expression on eosinophils corroborates the relevance of MC tryptase and PAR-2 on modulating eosinophil migration.

Versican expression in canine carcinomas in benign mixed tumours: is there an association with clinical pathological factors, invasion and overall survival?

BACKGROUND: Components of the extracellular matrix have been studied in an attempt to elucidate the mechanisms involved in the biological behaviour of tumours. The presence of the proteoglycan versican has been strongly associated with cancer development and progression. However, relationship between versican expression and clinical pathological factors and overall survival has not been previously studied in veterinary medicine. Carcinomas in benign mixed tumours (CBMTs) are one of the most common malignant tumours in female canines and can serve as models for studies of tumour progression. The aim of this study was to evaluate the expression of versican in in situ and invasive carcinomatous areas of canine CBMTs and to evaluate possible associations of versican expression with other classic prognostic factors and overall survival. RESULTS: Clinical staging; histological grade determination; immunohistochemical staining for versican, E-cadherin and Ki-67; and confirmation of invasion areas by staining for p63 and smooth muscle α-actin (α-SMA) were performed on 49 canine cases of CBMT. Tumour invasion was considered when suspicious Haematoxylin-Eosin (HE)-stained areas showed a total loss of α-SMA and p63 immunoreactivity. Versican immunoreactivity was less intense in the areas adjacent to the in situ carcinomatous regions, compared to invasive regions, which showed extensive and strong staining. CONCLUSIONS: Our data reveal that in canine CBMTs, versican expression differs significantly between invasive and in situ areas, suggesting a role for this molecule in tumour progression. Although a direct relationship exists between versican and invasiveness, our results indicate that the isolated evaluation of this proteoglycan does not represent an independent prognostic factor in canine CBMTs.