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Simple Summary Equine sarcoids, caused by bovine papillomaviruses, are equine skin tumors of fibroblastic origin. It is well known that bovine papillomaviruses are able to interfere with the survival and proliferation of cells by regulating autophagy, a mechanism implicated in the breakdown and reuse of old and damaged cellular material. The present study focused on the evaluation in equine sarcoids and normal skins of the expression level of some of the main proteins involved in the autophagic pathway, such as Beclin 1, LC3 and P62, by immunohistochemical and biochemical techniques. Results obtained in equine sarcoids suggested an alteration of the autophagic process which could lead to a predominance of a particular population of fibroblast. Those fibroblasts could survive longer in a hypoxic microenvironment and produce more and/or altered collagen, giving an origin to the equine sarcoid. Abstract Background: It is well known that δ-bovine papillomaviruses (BPV-1, BPV-2 and BPV-13) are one of the major causative agents of equine sarcoids, the most common equine skin tumors. Different viruses, including papillomaviruses, evolved ingenious strategies to modulate autophagy, a complex process involved in degradation and recycling of old and damaged material. Methods: The aim of this study was to evaluate, by immunohistochemistry (IHC) and Western blot (WB) analysis, the expression of the main related autophagy proteins (Beclin 1, protein light chain 3 (LC3) and P62), in 35 BPV1/2 positive equine sarcoids and 5 BPV negative normal skin samples. Results: Sarcoid samples showed from strong-to-moderate cytoplasmic immunostaining, respectively, for Beclin 1 and P62 in >60% of neoplastic fibroblasts, while LC3 immunostaining was weak to moderate in ≤60% of neoplastic fibroblasts. Western blot analysis confirmed the specificity of the antibodies and revealed no activation of autophagic flux despite Beclin 1 overexpression in sarcoid samples. Conclusion: Results could suggest the activation of the initial phase of autophagy in equine sarcoids, and its impairment during the following steps. The impairment of autophagy could lead to a selection of a quiescent population of fibroblasts, which survive longer in a hypoxic microenvironment and produced more and/or altered collagen.

IntroductionBovine papillomaviruses −1/−2 (BPVs) are small non-enveloped double-stranded DNA viruses able to infect the skin of bovids and equids, causing development of neoplastic lesions such as bovine cutaneous fibropapillomas and equine sarcoid. Matrix metalloproteinases (MMPs) are a group of zinc-dependent endopeptidases that degrade basal membrane and extracellular matrix, whose function is essential in physiological processes such as tissue remodeling and wound healing. MMPs activity is finely regulated by a balancing with expression of tissue inhibitors of MMPs (TIMPs), a process that is impaired during tumour development. BPV infection is associated with upregulation of MMPs and /or their unbalancing with TIMPs, contributing to local invasion and impairment of extracellular matrix remodeling in equine sarcoid; however, studies regarding this topic in bovine fibropapillomas are lacking.MethodsThe aim of this study was to perform an immunohistochemical and biochemical analysis on a panel of MMPs and TIMPs in BPV-2 positive bovine cutaneous fibropapillomas vs. normal skin samples.ResultsImmunohistochemistry revealed a cytoplasmic expression of MMP-2 (15/19), a cytoplasmic and perinuclear immunoreactivity of MMP-7 (19/19) and MMP-9 (19/19), along with a cytoplasmic and nuclear pattern of MMP-14 (16/19), accompanied by a cytoplasmic expression of TIMP-1 (14/19) and TIMP-2 (18/19) in tumour samples; western blotting revealed an overexpression of MMP-2 (8/9), MMP-7 (9/9) and MMP-9 (9/9), and a decreased level of MMP-14 (9/9), TIMP-1 (9/9) and TIMP-2 (9/9) in tumour versus normal skin samples. Moreover, gelatine zymography confirmed the expression of pro-active MMP-2 (9/9) and MMP-9 (9/9) and, most importantly, indicated the presence and increased activity of their active forms (82 and 62 kDa, respectively) in tumour samples.DiscussionThis is the first study describing MMPs and TIMPs in bovine cutaneous fibropapillomas and our results suggest that their unbalanced expression in presence of BPV-2 may play a significant role in tumour development. A further analysis of supplementary MMPs and TIMPs could bring new important insights into the papillomavirus induced tumours.

Papillomavirus (PV) infection is associated with development of epithelial cancer in different species, including domestic cat (Felis catus). Felis catus PV type-2 (FcaPV-2) is considered the causative agent of a proportion of feline cutaneous squamous cell carcinoma (SCC), through the transforming properties of its E6 and E7 oncogenes. However, the possible role of FcaPVs in the aetiology of feline oral SCC (FOSCC) is still unclear. The aim of this study was to assess the presence and gene expression of FcaPV-2 in FOSCC samples. We detected FcaPV-2 DNA in 10/32 (31%) of the analysed FOSCC by the use of PCR methods. Importantly, viral mRNA was detected by RT-PCR in 7/10 (70%) of DNA positive samples. In particular, FcaPV-2 L1, E2 and E6E7 genes were found to be expressed in 5/10 (50%), 3/10 (33%) and 5/10 (50%) samples, respectively. Viral DNA was also detected in non neoplastic oral ulcerative lesions (ULs) (4/11, 36%); qPCR suggested a difference in viral load between ULs and FOSCCs, particularly in those expressing E6E7, although it was not statistically significant. These data suggest, but do not definively prove, a possible role of FcaPV-2 in the development of a proportion of FOSCC. Moreover, L1 and E2 gene expression results indicate that FcaPV-2 infection associated with these tumours may possibly be productive.

Expression of telomerase reverse transcriptase (TERT) and telomerase activity (TA) is a main feature of cancer, contributing to cell immortalization by causing telomeres dysfunction. BIBR1532 is a potent telomerase inhibitor that showed potential anti-tumor activities in several types of cancer, by triggering replicative senescence and apoptosis. In a previous work, we detected, for the first time, TERT expression and TA in preclinical models of feline oral squamous cell carcinoma (FOSCC); therefore, we aimed at extending our investigation by testing the effects of treatment with BIBR1532, in order to explore the role of telomerase in this tumor and foreshadow the possibility of it being considered as a future therapeutic target. In the present study, treatment of FOSCC cell lines SCCF1, SCCF2, and SCCF3 with BIBR1532 resulted in successful inhibition of TA, with subsequent cell growth stoppage and decrease in cell viability. Molecular data showed that up-regulation of cell cycle inhibitor p21, unbalancing of Bax/Bcl-2 ratio, and down-regulation of survival gene Survivin were mostly involved in the observed cellular events. Moreover, BIBR1532 diminished the expression of TERT and its transcriptional activator cMyc, resulting in the down-regulation of epidermal growth factor receptor (EGFR), phospho-ERK/ERK ratio, and matrix metalloproteinases (MMPs)-1/-2 and−9, likely as a consequence of an impairment of TERT extra-telomeric functions. Taken together, our data suggest that BIBR1532 exerts multiple anti-cancer activities in FOSCC by inhibiting telomerase pathway and interfering with signaling routes involved in cell proliferation, cell survival, and invasion, paving the way for future translational studies aimed at evaluating its possible employment in the treatment of this severe tumor of cats.

Human papillomaviruses are currently classified in different genera. Mucosal HPVs belonging to the alpha genus have been clearly associated with carcinogenesis of the mucosal epithelium at different sites. Beta HPV types have been classified as cutaneous. Although findings indicate that some beta HPVs from species 1 and 2 play a role, together with UV irradiation, in skin cancer, very little is known about the transforming properties of most of the beta HPVs. This report shows the transforming activity of E6 and E7 from beta-3 HPV types. Moreover, it highlights that beta-3 HPVs share some biological properties more extensively with mucosal high-risk HPV16 than with beta-2 HPV38. This report provides new paradigms for a better understanding of the biology of the different HPV types and their possible association with lesions at mucosal and/or cutaneous epithelia., The beta human papillomaviruses (HPVs) are subdivided into 5 species (beta-1 to beta-5), and they were first identified in the skin. However, the beta-3 species appears to be more highly represented in the mucosal epithelia than in the skin. Functional studies have also highlighted that beta-3 HPV49 shares some functional similarities with mucosal high-risk (HR) HPV16. Here, we describe the characterization of the in vitro transforming properties of the entire beta-3 species, which includes three additional HPV types: HPV75, HPV76, and HPV115. HPV49, HPV75, and HPV76 E6 and E7 (E6/E7), but not HPV115 E6 and E7, efficiently inactivate the p53 and pRb pathways and immortalize or extend the life span of human foreskin keratinocytes (HFKs). As observed for HR HPV16, cell cycle deregulation mediated by beta-3 HPV E6/E7 expression leads to p16INK4a accumulation, whereas no p16INK4a was detected in beta-2 HPV38 E6/E7 HFKs. As shown for HPV49 E6, HPV75 and HPV76 E6s degrade p53 by an E6AP/proteasome-mediated mechanism. Comparative analysis of cellular gene expression patterns of HFKs containing E6 and E7 from HR HPV16, beta-3 HPV types, and beta-2 HPV38 further highlights the functional similarities of HR HPV16 and beta-3 HPV49, HPV75, and HPV76. The expression profiles of these four HPV HFKs show some similarities and diverge substantially from those of beta-3 HPV115 E6/E7 and beta-2 HPV38 E6/E7 HFKs. In summary, our data show that beta-3 HPV types share some mechanisms with HR HPV types and pave the way for additional studies aiming to evaluate their potential role in human pathologies. IMPORTANCE Human papillomaviruses are currently classified in different genera. Mucosal HPVs belonging to the alpha genus have been clearly associated with carcinogenesis of the mucosal epithelium at different sites. Beta HPV types have been classified as cutaneous. Although findings indicate that some beta HPVs from species 1 and 2 play a role, together with UV irradiation, in skin cancer, very little is known about the transforming properties of most of the beta HPVs. This report shows the transforming activity of E6 and E7 from beta-3 HPV types. Moreover, it highlights that beta-3 HPVs share some biological properties more extensively with mucosal high-risk HPV16 than with beta-2 HPV38. This report provides new paradigms for a better understanding of the biology of the different HPV types and their possible association with lesions at mucosal and/or cutaneous epithelia.

Background: equine sarcoids are the most frequent skin tumors in equidae worldwide. It is well known that delta bovine papillomaviruses are their causative agents. We have recently shown the presence in equine sarcoids of abnormal vessel structures, which could cause a hypoxic condition. The aim of this study was to analyze the expression of hypoxia-inducible factor-1 alpha (HIF-1&alpha, ) in a subset of BPV positive equine sarcoids and explore the relationship with vascular endothelial growth factor (VEGF) expression. Results: 80% of equine sarcoids showed strong cytoplasmic staining in &gt, 60% of neoplastic fibroblasts, while 20% of samples showed a moderate cytoplasmic staining in 40&ndash, 60% of neoplastic fibroblasts for HIF-1&alpha, Results of Western blotting (WB) were consistent with immunohistochemistry (IHC). Moreover, a positive correlation between HIF-1&alpha, and VEGF expression (r = 0.60, p &lt, 0.01) was observed. Conclusion: we have shown that HIF-1&alpha, was strongly expressed in equine sarcoid. The upregulation of HIF-1&alpha, has been described in numerous tumors and can be modulated by many proteins encoded by transforming viruses. Thus, it is also possible that BPV could have a relevant role in HIF-1&alpha, pathway regulation, contributing to the development of equine sarcoids by promoting HIF-1&alpha, /VEGF mediated tumor angiogenesis.

This report describes the gross and histopathological features of a large, cauliflower-like skin mass located on the right metacarpal region of a 3-year-old, captive-born, male Grant's zebra (Equus quagga boehmi) housed at a private animal farm in Abruzzo region, Italy. Clinical and histopathological examinations allowed a diagnosis of fibroblastic sarcoid like in equine. Molecular examination by conventional PCR also allowed to detect BPV-1 DNA in tumour samples. Based on scientific literature, this is the first report describing the occurrence of a fibroblastic sarcoid in a Grant's zebra in Europe.

Telomerase activity contributes to cell immortalization by avoiding telomere shortening at each cell division; indeed, its catalytic subunit telomerase reverse transcriptase (TERT) is overexpressed in many tumors, including human oral squamous cell carcinoma (hOSCC). In these tumors, matrix metalloproteinases (MMPs), a group of zinc-dependent endopeptidases involved in cell migration, contribute to invasive potential of cancer cells. A proportion of hOSCC is associated with infection by high-risk human papillomavirus (HR-HPVs), whose E6 oncogene enhances TERT and MMPs expression, thus promoting cancer progression. Feline oral squamous cell carcinoma (FOSCC) is a malignant tumor with highly invasive phenotype; however, studies on telomerase activity, TERT, and MMPs expression are scarce. In this study, we demonstrate telomerase activity, expression of TERT, and its transcriptional activator cMyc along with expression of MMP-1, -2, and -9 in FOSCC-derived cell lines SCCF2 and SCCF3, suggesting a contribution by these pathways in cell immortalization and invasion in these tumors. Recent studies suggest that a sub-group of FOSCC as well as SCCF2 and SCCF3 are associated with Felis catus PV type-2 (FcaPV-2) infection. However, in this work, FcaPV-2 E6 gene knock-down caused no shift in either TERT, cMyc, or MMPs levels, suggesting that, unlike its human counterpart, the viral oncogene plays no role in their regulation.

Deformed wing virus (DWV) is capable of infecting honeybees at every stage of development causing symptomatic and asymptomatic infections. To date, very little is known about the histopathological lesions caused by the virus. Therefore, 40 honeybee samples were randomly collected from a naturally DWV infected hive and subjected to anatomopathological examination to discriminate between symptomatic (29) and asymptomatic (11) honeybees. Subsequently, 15 honeybee samples were frozen at −80° and analyzed by PCR and RTqPCR to determinate the presence/absence of the virus and the relative viral load, while 25 honeybee samples were analyzed by histopathological techniques. Biomolecular results showed a fragment of the expected size (69bp) of DWV in all samples and the viral load was higher in symptomatic honeybees compared to the asymptomatic group. Histopathological results showed degenerative alterations of the hypopharyngeal glands (19/25) and flight muscles (6/25) in symptomatic samples while 4/25 asymptomatic samples showed an inflammatory response in the midgut and the hemocele. Results suggest a possible pathogenic action of DWV in both symptomatic and asymptomatic honeybees, and a role of the immune response in keeping under control the virus in asymptomatic individuals.

Papillomaviruses (PVs) are small, non-enveloped DNA viruses that cause mucocutaneous tumours including squamous cell carcinoma (SCC) in man. In animals, evidence supports a causal role for PVs in the develop- ment of cutaneous and oral SCC in some species. In reptiles, three cases of papilloma or fibropapilloma have been associated with PV infection, but no association has been reported to date with SCC. Two cases of cutaneous epithelial tumours, multiple papillomas in a spiny-tailed lizard (Uromastyx acanthinura) and SCC in a Dumeril’s boa (Acrantophis dumerili), were investigated by polymerase chain reaction. PV DNA was amplified from samples of both lesions. Typical microscopical features suggestive of PV infection (e.g. the presence of koilocytes) were observed in the lesions from the spiny-tailed lizard. This is the first report of an association between PV and SCC in reptiles. Further studies are needed to better clarify the role of PVs in these species and to characterize the PV strains involved.

Canine mammary tumours are frequent neoplasms mostly affecting intact female dogs, for which no 100% efficient therapy is available. Platelet derived growth factor β receptor (PDGFβR) is a tyrosine kinase receptor (TKR) with a potential role in human breast cancer and a series of canine tumours. In this study we demonstrated, for the first time, expression of PDGFβR and its downstream transduction molecules, mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) and extracellular signal-regulated kinase (ERK), as well as their activated forms in canine mammary tumours by both biochemical analysis and immunohistochemistry. PDGFβR was expressed and hyperphosphorylated in the majority of tumour samples and tumour derived cell lines. Additionally, both MEK and ERK were expressed and activated in cell lines as well as biopsies. TKR inhibitors (TKRi) are currently under investigation as possible therapy in human breast and several canine tumours, thus our in vivo and in vitro findings pave the way for future studies aimed at establishing a potential therapeutic employment of TKRi for the treatment of canine mammary cancer.

In the last twenty years, many concerns have raised in Campania region (Southern Italy) about illegal waste dumping and toxic waste and their possible adverse effects on health. Many human activities are considered to be important sources of environmental pollutants, elements among them. In this study, pet dogs were enrolled as environmental sentinels from three different areas of Campania, with a different degree of pollution, evaluating elements in blood and hair. The obtained data indicated that dogs from less polluted area were exposed to a hot spot of pollution, as only animals from one city (Sessa Aurunca) presented elements concentrations very close to toxic levels. When excluding these animals, the area proved to be the less contaminated. The present report confirm the higher degree of pollution of the most industrialized areas, and a certain concern originates from Cr, Ni and As, which are present as levels well above toxic thresholds. These data are indicative of a reduced pollution of the areas considered by Cd and Pb, but arise concern for Hg, As, Cr and Ni, which reach concentrations high enough to impact dogs and humans health, in term of acute (in the city of Sessa Aurunca) and chronic toxicity (i.e. reproduction impairment, endocrine disruption, immunosuppression). Additional studies are necessary to better define not only the precise distribution of hot spots of pollution, but also the real impact of such an exposure on the health of dogs, in term of endocrine balance and/or immune system activity.

Felis catus papillomavirus type 2 (FcaPV2) DNA is found in feline cutaneous squamous cell carcinomas (SCCs); however, its biological properties are still uncharacterized. In this study, we successfully expressed FcaPV2 E6 and E7 putative oncogenes in feline epithelial cells and demonstrated that FcaPV2 E6 binds to p53, impairing its protein level. In addition, E6 and E7 inhibited ultraviolet B (UVB)-triggered accumulation of p53, p21 and pro-apoptotic markers such as Cleaved Caspase3, Bax and Bak, suggesting a synergistic action of the virus with UV exposure in tumour pathogenesis. Furthermore, FcaPV2 E7 bound to feline pRb and impaired pRb levels, resulting in upregulation of the downstream pro-proliferative genes Cyclin A and Cdc2. Importantly, we demonstrated mRNA expression of FcaPV2 E2, E6 and E7 in feline SCC samples, strengthening the hypothesis of a causative role in the development of feline SCC.

Neurotrophins (NTs) and their specific Trk-receptors are key molecules involved in the regulation of survival, proliferation, and differentiation of central nervous system during development and adulthood in vertebrates. In the present survey, we studied the expression and localization of neurotrophins and their Trk-receptors in the cerebellum of teleost fish Danio rerio (zebrafish). Teleostean cerebellum is composed of a valvula, body and vestibulolateral lobe. Valvula and body show the same three-layer structure as cerebellar cortex in mammals. The expression of NTs and Trk-receptors in the whole brain of zebrafish has been studied by Western blotting analysis. By immunohistochemistry, the localization of NTs has been observed mainly in Purkinje cells; TrkA and TrkB-receptors in cells and fibers of granular and molecular layers. TrkC was faintly detected. The occurrence of NTs and Trk-receptors suggests that they could have a synergistic action in the cerebellum of zebrafish. J. Morphol. 277:725-736, 2016. © 2016 Wiley Periodicals, Inc.

Background: Sarcoids are the mostcommon skin tumors in horses, ch aracterized by rare regression, invasiveness and high recurrence following surgical intervention and Delta Papillomaviruses are widely recognized as the causative agents of the disease. In order to gain new insights into equine sarco id development, we have evaluated, in 25 equine sarcoids, by immunohistochemistry and western blotting analysis, the expression levels of VEGF, Ki67 and bcl-2. Moreover, we have measured microvessel density an d specific vessel parameters. Results: All sarcoid samples showed a strong and finely granular cytoplasmatic staining for VEGF in the majority (90%) of keratinocytes, sarcoid fibroblasts and endothelial cells. Numerous small blood vessels, immunostained with Von Willebrand factor, often appeared irregular in shape and without a distinct lumen, with mean values of microvessel area and perimeter lower than normal. Moreover, in all sarcoid samples, Ki67 immunoreactivity was moderately positive in 5 – 10% of dermal sarcoid fibroblasts, while Bcl2 immunoreactivity was detected in 52% of the sarcoid samples, with a weak staining in 20 – 50% of dermal sarcoid fibroblasts. Biochemical analysis was consistent with immunohistochemical results. Conclusions: This study has provided evidence that in equine sarcoid: VEGF was strongly expressed; the increased number of vessels was not associated with their complete maturation, probably leading to a hypoxic condition, which could increase VEGF synthesis; the levels of sarcoid fibroblasts proliferation were very low. Concluding, VEGF may have a role in equine sarcoid development, not only through the increase of angiogenesis, but also through the control of sarcoid fibroblast activity.

Papillomaviruses (PVs) are small DNA viruses that induce benign and/or malignant epithelial tumours in different species, including the domestic cat (Felis catus). To date, five F. catus papillomavirus genotypes have been identified (FcaPV-1 to FcaPV-5). FcaPV-1 is associated with skin and oral benign lesions, while FcaPV-2 infection is widely associated with feline squamous cell carcinomas. Several human and animal PVs have been found in body fluids such as peripheral blood; however, the presence of FcaPVs in non-epithelial tissues has not previously been investi- gated. The aim of this study was to assess the presence and gene expression of FcaPV-1 and FcaPV-2 in the blood of healthy cats. We detected FcaPV-2 DNA in 26 of 103 (25%) blood samples. Importantly, FcaPV-2 L1, E2, E6 and E7 genes were found to be expressed in 3 (25%), 11 (92%), 6 (50%) and 5 (42%) of the samples available for mRNA analysis, respectively. FcaPV-1 was not detected in any of the blood samples analysed here. The data obtained in this work suggest active and eventually productive infection of FcaPV-2 in the blood of healthy cats, implying a possible role in intra-individual spreading as well as in vertical and horizontal trans- mission.

E6 from high risk human papillomaviruses (HR HPVs) promotes ubiquitination and degradation of p53 tumour suppressor by mediating its binding to ubiquitin ligase E6AP in a ternary complex, contributing to cell transformation in cervical cancer. We have previously shown that Felis catus papillomavirus type −2 (FcaPV-2) E6 is expressed in feline squamous cell carcinoma (SCC) and displays the ability to bind p53 and decrease its protein levels in transfected CRFK cells. However, the mechanism of p53 downregulation has not yet been characterized. Here we show that FcaPV-2 E6 bound to E6AP, which in turn was bound by p53 exclusively in cells expressing the viral oncoprotein (CRFKE6). Furthermore, p53 was highly poly-ubiquitinated and underwent accumulation upon E6AP gene knockdown in CRFKE6. Half-life experiments and proteasome inhibition treatments indicated that down-regulation of p53 protein in CRFKE6 was due to accelerated proteasomal degradation. E6AP/p53 binding was also demonstrated in two feline SCC cell lines expressing FcaPV-2 E6, where p53 protein levels and poly-ubiquitination degree were proportional to E6 mRNA levels. The data obtained in both artificial and spontaneous in vitro models suggest that FcaPV-2 E6 degrades p53 through a molecular mechanism similar to HR HPVs, possibly contributing to the development of feline SCC.

Oral squamous cell carcinoma (SCC) is a common finding in domestic and wild felids. Only two cases of oral SCC have been reported in Lynx species (Lynx rufus and Lynx canadensis), at mandibular and gingival sites. In this study, we describe the first report of tongue SCC in a 15 years old female European lynx (Lynx lynx), along with viral investigations. Necropsy and histological analysis were performed and the presence of papillomavirus (PV) infection was investigated by ultrastructural and molecular methods. The lardaceous mass at tongue level was histologically diagnosed as moderately differentiated SCC. Typical microscopical features of SCC were also found in the retropharyngeal lymph node and at the pulmonary level. Neither viral DNA by PCR, nor viral particles by transmission electron microscopy were found. Despite that PV infection is associated with Felidae, this work reports the first description of tongue SCC in Lynx species, but no evidence of PV infection, suggesting that PV may not be involved in development of SCC in bobcat species.

Bovine papillomaviruses (BPVs) can infect epithelial cells and fibroblasts, inducing fibropapillomas in cattle. Gap junctions are communication channels between cells composed of connexins (Cxs). This study evaluated expression of Cx26 and the major BPV oncoprotein E5 in bovine cutaneous fibropapillomas. BPV DNA was amplified from 20/20 fibropapillomas and 3/3 samples of normal skin. All fibropapillomas (20/20) were positive by immunostaining for E5, whereas the three normal skin samples were negative. Cx26 was expressed faintly in the normal skin epithelium. Positive cytoplasmic and juxtanuclear immunoreactivity for Cx26 was evident in 18/20 (90%) fibropapillomas. Western blot analysis demonstrated higher expression of Cx26 in 6/6 fibropapillomas compared to normal skin samples.

The 37/67 kDa laminin receptor (LR) is a non-integrin protein, which binds both laminin-1 of the extracellular matrix and prion proteins, that hold a central role in prion diseases. The 37/67 kDa LR has been identified as interactor for the prion protein (PrPC) and to be required for pathological PrP (PrPSc) propagation in scrapie-infected neuronal cells, leading to the possibility that 37/67 kDa LR-PrPC interaction is related to the pathogenesis of prion diseases. A relationship between 37/67 kDa LR and PrPC in the presence of specific LR inhibitor compounds has not been investigated yet. We have characterized the trafficking of 37/67 kDa LR in both neuronal and non-neuronal cells, finding the receptor on the cell surface and nuclei and identified the 67 kDa LR as the almost exclusive isoform interacting with PrPC. Here, we show that the treatment with the 37/67 kDa LR inhibitor, NSC47924, affects both the direct 37/67 kDa LR-PrPC interaction in vitro and the formation of the immunocomplex in live cells, inducing a progressive internalization of 37/67 kDa LR and stabilization of PrPC on the cell surface. These data reveal NSC47924 as a useful tool to regulate PrPC and 37/67 kDa LR trafficking and degradation, representing a novel small molecule to be tested against prion diseases.

Bovine papillomaviruses (BPVs) are small DNA tumoral viruses able to induce benign cutaneous and/or mucosal epithelial lesions. Generally, the benign tumours affecting the skin or mucosa spontaneously regress, but under special circumstances, the defence system may be overwhelmed, thus leading to cancer, especially in the presence of immunosuppressant and mutagen agents from bracken fern. To date, thirteen different BPV genotypes have been associated with skin and mucosal tumours in cattle, and out of these, only four types (BPV-1, -2, -5 and -13) cross-infect other species. Recent investigations in vivo have revealed new insights into the epidemiology and pathogenesis of this viral infection. This review briefly discusses viral epidemiology, will give data on BPV genome structure and viral genes and will describe the cellular events and new aspects of both cutaneous and mucosal tumours in large ruminants. Finally, some aspects of active immunization will be described.

A possible causative role of Felis catus papillomavirus type 2 (FcaPV2) in the development of feline oral and cutaneous squamous cell carcinomas (SCC) has been recently suggested by demonstrating viral gene expression in vivo and transforming properties by its putative oncogenes E6 and E7 in vitro. The activated molecules MEK (pMEK), ERK (pERK) and Akt (pAkt) are signaling transduction effectors regulating cell proliferation and inhibition of apoptosis, which are critical steps towards tumour formation. Here, we show by Western blotting (WB) that expression of FcaPV2 E6 in feline epithelial cells enhances pMEK, pERK and pAkt levels compared to control cells. Additionally, we demonstrated by real-time quantitative PCR on epidermal growth factor receptor (EGFR) transcripts and WB that activation of these signaling routes is independent from EGFR differential gene expression, total protein levels or phosphorylation, unlike in human papillomavirus associated tumours. This study contributes to define the molecular scenario underlying FcaPV2-triggered pathogenesis of feline SCC.

Neurotrophins (NTs) and their specific Trk-receptors are key molecules involved in the regulation of survival, proliferation, and differentiation of central nervous system during development and adulthood in vertebrates. In the present survey, we studied the expression and localization of neurotrophins and their Trk-receptors in the cerebellum of teleost fish Danio rerio (zebrafish). Teleostean cerebellum is composed of a valvula, body and vestibulolateral lobe. Valvula and body show the same three-layer structure as cerebellar cortex in mammals. The expression of NTs and Trk-receptors in the whole brain of zebrafish has been studied by Western blotting analysis. By immunohistochemistry, the localization of NTs has been observed mainly in Purkinje cells; TrkA and TrkB-receptors in cells and fibers of granular and molecular layers. TrkC was faintly detected. The occurrence of NTs and Trk-receptors suggests that they could have a synergistic action in the cerebellum of zebrafish. J. Morphol. 277:725-736, 2016. © 2016 Wiley Periodicals, Inc.

Background Bovine cutaneous fibropapillomas are benign hyperproliferative lesions induced by Bovine Papillomaviruses (BPVs). Bcl-2 is an important anti-apoptotic protein which is expressed in several cancer types. In contrary, p53 is a tumour suppressor protein that mediates cell cycle arrest, apoptosis and senescence in response to cellular stresses. Findings Here, we investigated immunohistochemically and biochemically, the expression of bcl-2 and p53 in a subset of BPV positive fibropapillomas and bovine normal skin. Normal skin samples showed a weak signal for both proteins in the cytoplasm of the basal cells. Nine out of twelve (75%) tumour samples stained positive for bcl-2 throughout basal and parabasal layers, with most of cells showing strong cytoplasmic immunoreactivity. Nine out of twelve (75%) fibropapillomas were found to be positive for p53 expression, showing a strong cytoplasmic and perinuclear staining of p53 protein mainly in the basal and parabasal layers. Conclusions Our data reveal an altered bcl-2 and p53 immunoreactivity in bovine cutaneous fibropapillomas, suggesting involvement of these two proteins in the cutaneous neoplastic transformation through an impaired apoptotic process. Electronic supplementary material The online version of this article (doi:10.1186/1750-9378-10-2) contains supplementary material, which is available to authorized users.