Pietro Asproni

Immunohistochemical expression of COX-2, mPGES and EP2 receptor in normal and reactive canine bone and in canine osteosarcoma.

Accumulating evidence suggests that cyclooxygenase (COX)-2 is involved in the pathogenesis of human and canine osteosarcoma. The aim of this study was to investigate the expression of COX-2 in normal, reactive and neoplastic canine bone and the events downstream to COX-2 that lead to prostaglandin E(2) (PGE(2)) production. COX-2, microsomal PGE(2) synthase-1 (mPGES-1) and the PGE(2) receptor (EP2) were assessed by immunohistochemistry in 12 samples of normal bone, 14 cases of fracture callus and 27 appendicular osteosarcomas. No immunoreactivity to COX-2, mPGES-1 or EP2 receptor was observed in normal bone. Fifty percent of reactive bone samples expressed COX-2 and 57% expressed mPGES-1 and EP2 receptor, although with weak labelling intensity. Ninety-three percent of osteosarcomas expressed COX-2, while mPGES-1 was expressed by 85% and EP2 receptor by 89% of the tumours. The data confirm that COX-2 is expressed at high level in osteosarcoma and support the use of COX-2 inhibitors to improve the response to chemotherapy. The possibility of blocking the EP2 or the selective inhibition of mPGES-1, rather than COX-2 activity, might decrease the incidence of adverse effects that occur due to the inhibition of prostanoids other than PGE(2).

Molecular Phenotype in Mammary Tumours of Queens: Correlation between Primary Tumour and Lymph Node Metastasis

The molecular characterization of mammary tumours represents a new stage in the development of effective predictive models and targeted therapies. The aim of this study was to evaluate the relationship between the molecular phenotype of a primary feline mammary tumour and that of a related lymph node metastasis. Twenty-one mammary tumour samples and their lymph node metastases were selected and evaluated immunohistochemically for expression of oestrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (c-erbB-2), cytokeratin 5/6, cytokeratin 14, cytokeratin 19 and protein 63. Mammary tumours were classified into five subtypes: luminal A, luminal B, c-erbB-2 overexpressing, basal-like and normal-like, based on an algorithm applied in both human and veterinary medicine. Concordance between the primary tumour and its lymph node metastasis was detected in 12 of 21 cases (57.1%). In the remaining nine cases (42.9%) there was discordance in the molecular profile at the two sites. Therefore, the tumour molecular profile must be evaluated in both sites in order to obtain definitive identification of the tumour profile (or profiles) and to plan an appropriate therapy.

Molecular portrait-based correlation between primary canine mammary tumor and its lymph node metastasis: possible prognostic-predictive models and/or stronghold for specific treatments?

BackgroundThis study aimed to evaluate the relationship between the molecular phenotype of the primary mammary tumor and its related lymph node metastasis in the dog to develop prognostic-predictive models and targeted therapeutic options.ResultsTwenty mammary tumor samples and their lymph node metastases were selected and stained by immunohistochemistry with anti-estrogen receptor (ER), -progesterone receptor (PR), -human epidermal growth factor receptor 2 (c-erbB-2), -cytokeratin 5/6 (CK 5/6), -cytokeratin 14 (CK14), -cytokeratin 19 (CK 19) and -protein 63 (p63) antibodies. Four phenotypes (luminal A, luminal B, c-erbB2 overexpressing and basal-like) were diagnosed in primary tumors and five (luminal A, luminal B, c-erbB-2 overexpressing, basal-like and normal-like) in the lymph node metastases. Phenotypic concordance was found in 13 of the 20 cases (65%), and seven cases (35%) showed discordance with different lymph node phenotypic profile from the primary tumor.ConclusionsThe phenotype of the primary tumor assumes a predictive-therapeutic role only in concordant cases, meaning that both the primary tumor and its lymph node metastasis should be evaluated at the same time. A treatment plan based only on the primary tumor phenotype could lead to therapeutic failures if the phenotype of the lymph node metastasis differs from that of the primary tumor.

COX-2, mPGES-1 and EP2 receptor immunohistochemical expression in canine and feline malignant mammary tumours

Prostaglandin (PG) signalling is involved in human and animal cancer development. PG E2 (PGE2 ) tumour-promoting activity has been confirmed and its production is controlled by Cyclooxygenase-2 (COX-2) and microsomal PGE synthase-1 (mPGES-1). Evidence suggests that mPGES-1 and COX-2 contribute to carcinogenesis through the EP2 receptor. The aim of our study was to detect by immunohistochemistry COX-2, mPGES-1 and EP2 receptor expression in canine (n = 46) and feline (n = 50) mammary tumours and in mammary non-neoplastic tissues. COX-2 positivity was observed in 83% canine and 81% feline mammary carcinomas, mPGES-1 in 75% canine and 66% feline mammary carcinomas and the EP2 receptor expression was observed in 89% canine and 54% feline carcinomas. The frequency of COX-2, EP2 receptor and mPGES-1 expression was significantly higher in carcinomas than in non-neoplastic tissues and adenomas. COX-2, mPGES-1 and EP2 receptor expression was strongly associated. These findings support a role of the COX-2/PGE2 pathway in the pathogenesis of these tumours.

Amyloidosis in association with spontaneous feline immunodeficiency virus infection

Tissues from 34 naturally feline immunodeficiency virus (FIV)-infected cats, 13 asymptomatic cats and 21 cats with signs of feline acquired immunodeficiency syndrome (F-AIDS), and 35 FIV-seronegative subjects were examined to determine the presence of amyloid deposits. Twenty experimentally FIV-infected cats and five specific pathogen-free (SPF) control cats were also included in the study. Paraffin-embedded sections from kidney and other organs were submitted to histological and histochemical analysis. Amyloid deposits were identified by a modified Congo red stain and confirmed by electron microscopy to demonstrate the presence of amyloid fibrils in amyloid positive glomeruli. In all positive cases, secondary amyloidosis was identified with potassium permanganate pretreatment and amyloid type was further characterised by immunohistochemistry using primary antibodies against human AA and feline AL amyloids. Amyloid deposits were present in different tissues of 12/34 (35%) naturally FIV-infected cats (seven presenting F-AIDS and five in asymptomatic phase) and in 1/30 FIV-seronegative cats. All the experimentally FIV-infected and SPF subjects showed no amyloid deposits. Amyloidosis has been reported in human lentiviral infections, and the data reported here demonstrate the need, in naturally FIV-infected cats, to consider the presence of amyloidosis in differential diagnosis of hepatic and renal disorders to better assess the prognosis of the disease.

Immunohistochemical expression of cyclooxygenase-2 in normal, hyperplastic and neoplastic canine lymphoid tissues.

There is much interest in the potential use of selective inhibitors of cyclooxygenase (COX)-2 in combination with other cancer therapeutics. COX-2 is a key enzyme in prostaglandin synthesis and has been implicated in the pathogenesis of numerous canine and feline malignancies. There are few data on the potential role of COX-2 in the pathogenesis of canine lymphoma. The present study examined COX-2 expression in normal, hyperplastic and neoplastic canine lymphoid tissues. Immunohistochemical expression was evaluated in 12 samples of non-pathologically enlarged normal lymph nodes, 24 samples of hyperplastic lymph node and 44 samples of lymphoma (22 B-cell and 22 T-cell lymphomas). The labelling was scored semiquantitatively and a score of +2 or +3 was interpreted as overexpression. In hyperplastic lymph nodes only a few macrophages were COX-2-positive while six of the 44 lymphomas (13.6%; three B- and three T-cell lymphomas) overexpressed COX-2. These data provide a rationale for further investigation of COX-2 expression in canine lymphoma for prognostic, chemopreventive and chemotherapeutic purposes.

Molecular Phenotype of Primary Mammary Tumours and Distant Metastases in Female Dogs and Cats

Distant metastases represent a major step in the progression and fatal outcome of canine and feline mammary carcinomas. Recent studies have characterized the molecular phenotypes of mammary tumours and provided information on molecules that may allow targeted therapy in sites from which the tumours may not readily be surgically resected. Molecular phenotypes were determined immunohistochemically in three feline and two canine cases of mammary neoplasia, each presenting with multiple distant metastases. These tumours and their metastases often overexpressed the c-erbB-2 phenotype. A basal-like phenotype was found in the distant metastases from two cases. These findings suggest that canine and feline mammary tumours with distant metastases may be amenable to novel targeted therapies.

A case of feline primary inflammatory mammary carcinoma: clinicopathological and immunohistochemical findings

The clinicopathological and immunohistochemical findings of a primary feline mammary tumour with features similar to human and canine primary inflammatory carcinoma are described for the first time. The cat presented to the clinic for the rapid onset of oedema, severe erythema, local pain and warmth of the inguinal region, with a pustular-to-nodular cutaneous lesion in association with an ill-defined underlying mass. An epithelial malignant tumour was diagnosed by cytological investigation. Necropsy revealed a thickening of the skin with oedema of the subcutis in the right inguinal area, and regional and distant metastases. Histology showed an unencapsulated tubulopapillary proliferation of malignant epithelial cells, with a massive embolisation in the dermal lymphatics and a mild inflammatory infiltrate. Through immunohistochemistry, the tumour was found to be oestrogen (ER)-alpha-, androgen (AR)- and progesterone (PR)-negative; neoplastic cells were ER-alpha, AR-negative and focally PR-positive. An irregular, mild and focal HER-2 immunoreactivity was present (score +1, non-HER-2 overexpressing). The neoplastic cells were cyclo-oxygenase-2 and vascular endothelial growth factor positive.

Isolation and characterization of olfactory ecto-mesenchymal stem cells from eight mammalian genera

BackgroundStem cell-based therapies are an attractive option to promote regeneration and repair defective tissues and organs. Thanks to their multipotency, high proliferation rate and the lack of major ethical limitations, “olfactory ecto-mesenchymal stem cells” (OE-MSCs) have been described as a promising candidate to treat a variety of damaged tissues. Easily accessible in the nasal cavity of most mammals, these cells are highly suitable for autologous cell-based therapies and do not face issues associated with other stem cells. However, their clinical use in humans and animals is limited due to a lack of preclinical studies on autologous transplantation and because no well-established methods currently exist to cultivate these cells. Here we evaluated the feasibility of collecting, purifying and amplifying OE-MSCs from different mammalian genera with the goal of promoting their interest in veterinary regenerative medicine.Biopsies of olfactory mucosa from eight mammalian genera (mouse, rat, rabbit, sheep, dog, horse, gray mouse lemur and macaque) were collected, using techniques derived from those previously used in humans and rats. The possibility of amplifying these cells and their stemness features and differentiation capability were then evaluated.ResultsBiopsies were successfully performed on olfactory mucosa without requiring the sacrifice of the donor animal, except mice. Cell populations were rapidly generated from olfactory mucosa explants. These cells displayed similar key features of their human counterparts: a fibroblastic morphology, a robust expression of nestin, an ability to form spheres and similar expression of surface markers (CD44, CD73). Moreover, most of them also exhibited high proliferation rates and clonogenicity with genus-specific properties. Finally, OE-MSCs also showed the ability to differentiate into mesodermal lineages.ConclusionsThis article describes for the first time how millions of OE-MSCs can be quickly and easily obtained from different mammalian genera through protocols that are well-suited for autologous transplantations. Moreover, their multipotency makes them relevant to evaluate therapeutic application in a wide variety of tissue injury models. This study paves the way for the development of new fundamental and clinical studies based on OE-MSCs transplantation and suggests their interest in veterinary medicine.

Pathology and behaviour in feline medicine: investigating the link between vomeronasalitis and aggression.

Objectives The aim of the study was to investigate if the feline vomeronasal organ (VNO) can be affected by inflammatory lesions and if these changes are associated with behavioural alterations. Methods VNOs from 20 cats were sampled during necropsy, submitted for routine tissue processing and stained with haematoxylin and eosin for histopathological evaluation. For the 20 cats, data on the presence of aggressive behaviours towards cats or humans were collected by questionnaire survey at the point of death. Inflammatory lesions were classified depending on the duration of the process as acute or chronic, both in vomeronasal sensory epithelium (VNSE) and in non-sensory epithelium (NSE). Fisher’s exact test was used to compare VNO inflammation with behavioural data. Results The VNSE was inflamed in 11/20 VNOs (55%) while the NSE was inflamed in 13/20 (65%). Overall, the VNO was affected by inflammation in 14/20 (70%) cats, and all the lesions were classified as chronic. Five out of 20 cats (25%) had documented intraspecific aggressive behaviours and 8/20 (40%) had shown aggression towards humans. Fisher’s exact test showed a statistically significant correlation between inflammation of the VNSE and intraspecific aggression (P = 0.038). No statistically correlations were observed between VNSE inflammation and aggression towards humans and between NSE inflammation and aggression towards cats or humans. Conclusions and relevance Our results show, for the first time, the existence of vomeronasalitis in animals and its possible association with intraspecific aggressive behaviours. The inflammatory microenvironment could impair VNSE functionality, causing intraspecific communication alterations, probably through a reduction in chemical communication action and perception. Owing to the pivotal role of the VNO in the social life of cats and other species, this report provides a rationale to further investigate this disease in relation to a variety of behavioural disorders.