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The article discusses the effect of cancer chemopreventive compounds on the progression of neoplastic cells to malignancy in dogs. Cancer chemopreventive compounds that have been considered include nonsteroidal anti-inflammatory drugs (NSAIDs), peroxisome proliferator-activated receptor-ϒ (PPAR-ϒ) ligands, and dietary compounds. Findings of the chemopreventive research in canine cancer indicate the feasibility and potential of the chemopreventive agents in treating canine cancer.

Background: Malignant tumors are the main cause of death or euthanasia in animals. The oral cavity ranking fourth in number of occurrences. Epidemiological studies with dogs suggest that canine cancer kills 40-50% of individuals aged over 10 years. In view of the interest of academics and professionals in the healthcare of dogs and cats, this paper reports the case of a 10-month-old bitch, which, despite being a young animal, was affected alveolar rhabdomyosarcoma of abrupt evolution. Case: A 10-month-old French Bulldog bitch, weighing 10 kg, was referred to a veterinary hospital in the city of Rio de Janeiro for care. It had a history of mouth bleeding, after chewing a solid mineral material, edema in the region of the right maxilla, and protusion of the gland of the third eyelid. As the clinical examination also revealed a fracture of the maxillary canine, anti-inflammatory and antibiotics were prescribed, to be administered by the owner once a day for 7 days. During the next clinical examination, carried out one week later, an edema was found in the right region of the mouth, which proved difficult to examine. As the patient had already eaten, an appointment was made for the following day for an intervention in the operating room, where the animal could be anesthetized for better observation of the effected region. Blood was collected for hemogram, urea, creatinine, alkaline phosphatase, ALT, and GGT, and an 8 h food fasting and a 4 h water fasting were recommended. On that date, once the dog had been taken to the operating room, was administered the pre anesthesia, in addition to anesthetic induction and manutention. Upon examining the oral cavity, several loose molars were found on the right side, in addition to a tumoral aspect of the gum; thus, it was decided to collect a small sample of the tumoral mass for histopathology. The surgical specimen was placed in a formalin solution and sent to the laboratory for histopathological processing and diagnosis. One week later, the tumor mass was larger and the edema in the right region of the mouth was much larger than on the day of the procedure. Thus, a computerized tomography was requested to further investigate the alterations that had occurred in such a short time. Due to the results of the histopathology and the CT, an immunohistochemical test was suggested which determined the cell profile and morphology and confirmed the diagnosis of alveolar rhabdomyosarcoma according to clinical suspicion. The animal remained in the veterinary hospital for a further 48 h, during which the clinical condition worsened, with the animal suffering heavy bleeding. As the patient was no longer capable of oral intake of food or water, the decision was made with the consent of the owners to induce a painless death to alleviate the suffering of the animal. However, the owners did not authorize a necropsy. Discussion: Veterinary physicians should be conscious of the treatment of serious illnesses that will not result in a benefit for the patient. They should know when to stop the treatment to not cause further pain and suffering to the animals and their owners. Many of the interventions which aim to treat severe malignant neoplasia will not promote an improvement in quality of life or significantly extend the patient’s survival, and do not justify the suffering they entail. A painless death remains the best alternative in such cases. [ABSTRACT FROM AUTHOR]

Background: The squamous cell carcinoma is a malignant tumor of epidermal cells in which the cells show differentiation to keratinocytes. It is a common neoplasm affecting all domestic animals and other mammalian species. There are several factors that are associated with the development of a squamous cell carcinoma, including prolonged exposure to ultraviolet light, lack of pigment within the epidermis at the sites of tumor development, and lack of hair or a very sparse hair coat at the affected sites. They can appear anywhere on the animal's body predominantly in areas devoid of hair and ears, eyelids, nose and perineal area. Squamous cell carcinoma may occur in young animals, but the incidence increases with age. The cut surface of the tumor appears grainy, whitish or yellowish. These tumors are very infiltrative but rarely metastasize. Microscopically there is the characteristic feature of squamous cell carcinomas and well differentiated with abundant proliferation of stromal. The tumor is common in the horse, cow, cat, and dog, relatively uncommon in the sheep, and rare in the goat and pig. In sheep and goats there are few data in literature. This paper reports a case of squamous cell carcinoma in the frontal region of the head in a Pardo Alpino goat in Bahia. Case: An 6-year-old female Pardo Alpino goat was made euthanasia and sent for necropsy to the Laboratório de Patologia Veterinária of Universidade Federal do Recôncavo da Bahia, Cruz das Almas (UFRB), Bahia, Brazil. According to the veterinarian the goat began to show a neoformation located in the front of the head. This period was performed surgical excision of the mass and cauterization, but the neoplasm recurred twice in succession. Due to the condition it was in, the animal was euthanized. The animal was necropsied and samples collected from the abdominal cavity, thoracic cavity, nervous system and integumentary system. The samples were fixed in 10% formalin, cleaved, processed routinely for histology, embedded in paraffin, cut at five microns thick and stained with hematoxylin and eosin. The necropsy was found mass measuring 5,0 x 3,5 x 3,5 cm in the frontal region of the head. The cut surface of the tumor had been firm and whitish. There were no metastasis in regional lymph nodes or others organs. Histopathological examination revealed a well-differentiated squamous cell carcinoma displaying central pearls of keratin and a dense fibrous stroma. The cytoplasm was abundant and eosinophilic with indistinct boundaries. Were observed 3-5 mitoses greater increase. Discussion: The diagnosis of squamous cell carcinoma of the goat was established by macroscopic and microscopic findings. In this report the neoplasm grew in the caudal region of the frontal sinus, near the spot where had been deshorned. The presence of squamous cell carcinoma located in the front of the head has not been reported in goats. In cattle there squamous cell carcinoma base of horn, diagnosis which could be considered in this case. These results are similar to those described by other authors. Was not found metastasis in regional lymph nodes and parenchymal organs. Most tumors, although invasive, do not show metastatic to regional lymph nodes. There are not papers in the literature of squamous cell carcinoma at this location. [ABSTRACT FROM AUTHOR]

Merkel cell tumors, a type of cutaneous round-cell tumors, are rarely observed in dogs and cats. This tumor type originates from cutaneous neuroendocrine cells. In the present study, the morphology of canine and feline Merkel cell tumors and their immunoexpression of neuron-specific enolase, cytokeratin, chromogranin A, Ki67, and metallothionein were evaluated using histopathological and immunohistochemical methods. The canine Merkel cell tumor displayed a diffuse morphological pattern, whereas the feline tumor displayed a solid morphological pattern. Both tumors were positive for neuron-specific enolase and cytokeratin, but negative for chromogranin A. The Ki67 indexes in the canine and feline tumors were 7% and 25%, respectively. The expression of metallothionein was minimal in both tumors. In conclusion, this paper describes the detailed histopathological and immunohistochemical features of uncommon canine and feline Merkel cell tumors, including metallothionein expression, which has never been studied in such tumors previously. [ABSTRACT FROM AUTHOR]

Naturally occurring cancers in non-laboratory species have great potential in helping to decipher the often complex causes of neoplasia. Wild animal models could add substantially to our understanding of carcinogenesis, particularly of genetic and environmental interactions, but they are currently underutilized. Studying neoplasia in wild animals is difficult and especially challenging in marine mammals owing to their inaccessibility, lack of exposure history, and ethical, logistical and legal limits on experimentation. Despite this, California sea lions (Zalophus californianus) offer an opportunity to investigate risk factors for neoplasia development that have implications for terrestrial mammals and humans who share much of their environment and diet. A relatively accessible California sea lion population on the west coast of the USA has a high prevalence of urogenital carcinoma and is regularly sampled during veterinary care in wildlife rehabilitation centres. Collaborative studies have revealed that genotype, persistent organic pollutants and a herpesvirus are all associated with this cancer. This paper reviews research to date on the epidemiology and pathogenesis of urogenital carcinoma in this species, and presents the California sea lion as an important and currently underexploited wild animal model of carcinogenesis. [ABSTRACT FROM AUTHOR]

Evolutionary considerations suggest that oncogenic infections should be pervasive among animal species. Infection-associated cancers are well documented in humans and domestic animals, less commonly reported in undomesticated captive animals, and rarely documented in nature. In this paper, we review the literature associating infectious agents with cancer to evaluate the reasons for this pattern. Non-malignant infectious neoplasms occur pervasively in multicellular life, but oncogenic progression to malignancy is often uncertain. Evidence from humans and domestic animals shows that non-malignant infectious neoplasms can develop into cancer, although generally with low frequency. Malignant neoplasms could be difficult to find in nature because of a low frequency of oncogenic transformation, short survival after malignancy and reduced survival prior to malignancy. Moreover, the evaluation of malignancy can be ambiguous in nature, because criteria for malignancy may be difficult to apply consistently across species. The information available in the literature therefore does not allow for a definitive assessment of the pervasiveness of infectious cancers in nature, but the presence of infectious neoplasias and knowledge about the progression of benign neoplasias to cancer is consistent with a widespread but largely undetected occurrence. [ABSTRACT FROM AUTHOR]

Background Canine mammary sarcomas (CMSs) are rarely diagnosed in female dogs, which explains the scarcity of immunohistochemical findings concerning those tumors. This paper presents the results of a retrospective study into CMSs and discusses the clinical features of the analyzed tumors, the expression of intermediate filaments CK, Vim, Des and α-SMA, and the expression of p63, Ki67, ERα, PR and p53 protein. Results Four percent of all canine mammary tumors (CMTs) were classified as CMSs, and they represented 5.1% of malignant CMTs. The mean age at diagnosis was 11.1 ± 2.8 years. Large breed dogs were more frequently affected (38.7%). The majority of observed CMSs were fibrosarcomas (2.1%). All CMSs expressed vimentin, and higher levels of vimentin expression were noted in fibrosarcomas and osteosarcomas. Ki67 expression was significantly correlated with the grade of CMS. Conclusions Our results revealed that CMSs form a heterogeneous group, therefore, immunohistochemical examinations could support differential and final diagnosis. Although this study analyzed a limited number of samples, the reported results can expand our knowledge about CMSs. Further work is required in this field. [ABSTRACT FROM AUTHOR]

Electrochemotherapy (ECT) is a novel anticancer therapy that is currently being evaluated in human and pet cancer patients. ECT associates the administration of an anti-tumor agent to the delivery of trains of appropriate waveforms. The increased uptake of chemotherapy leads to apoptotic death of the neoplasm thus resulting in prolonged local control and extended survival. In this paper we describe the histological features of a broad array of spontaneous tumors of companion animals receiving pulse-mediated chemotherapy. Multivariate statistical analysis of the percentage of necrosis and apoptosis in the tumors before and after ECT treatment, shows that only a high percentage of necrosis and apoptosis after the ECT treatment were significantly correlated with longer survivals of the patients (p < 0.0001 and p = 0.004, respectively). Further studies on this topic are warranted in companion animals with spontaneous tumors to identify new molecular targets for electrochemotherapy and to the develop new therapeutical protocols to be translated to humans. [ABSTRACT FROM AUTHOR]

Sera from mice with large tumours from a variety of tissue types and sources have been shown to contain substances capable of suppressing the proliferative response of normal mouse lymphocytes to concanavalin A (Con A), bacterial endotoxin (LPS) and allogeneic cells. The present paper deals with studies on the nature of these inhibitory materials using mainly a methylcholanthreneinduced rhabdomyosarcoma in DBA/2J mice. It was found that a material responsible for inhibition of the Con A response eluted with immunoglobulins on Sephadex G-150 and eluted with monomeric immunoglobulin on Sephadex G-200. The component of tumour-bearer serum responsible for the suppression of the LPS response of normal lymphocytes eluted from Sephadex G-150 with the α and β globulins and albumin (molecular weight < 150,000). The immunoglobulin-containing serum fraction from tumour-bearing animals inhibited the mixed lymphocyte response, Con A response, and specific immune response to purified protein derivative (PPD) in allogeneic cell systems. It also inhibited the in vitro primary response of mouse cells to sheep red blood cells, and, to a lesser extent, the response to a T cell-independent antigen (DNP-dextran). The inhibitory activity continued to elute with monomeric IgG on Sephadex G-200 when columns were run in 1640 medium and adjusted to pH 2.5, indicating that an acid dissociable complex was not responsible for inhibitory activity. Inhibitor activity could be removed by absorption on immunoadsorbents containing goat anti-mouse immunoglobulin, and could be recovered by acid elution from the adsorbent. Inhibitor activity was not removed by immunoadsorption on columns prepared with antisera to chicken immunoglobulin. [ABSTRACT FROM AUTHOR]

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A method of automated synthesis of [18F]fluoromisonidazole ([18F]FMISO) for application in preclinical studies on small animals was presented. A remote-controlled synthesizer Synthra RNplus was used for nucleophilic substitution of NITTP (1′-(2′-nitro-1-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulfonyl-propanediol) with 18F anion. Labeling of 5 mg of precursor was performed in anhydrous acetonitrile at 100°C for 10 min, and the hydrolysis with HCl was performed at 100°C for 5 min. Final purification was done with high-performance liquid chromatography (HPLC) and the radiochemical purity of radiotracer was higher than 99%. Proposed [18F]FMISO synthesis was used as a reliable tool in studies on hypoxia in Lewis lung carcinoma (LLC) in mouse models. [ABSTRACT FROM AUTHOR]

Objective--To elucidate factors influencing practitioner decisions to refer dogs with cancer to veterinary oncology specialists. Design--Cross-sectional study. Sample--2,724 Ontario primary care companion animal veterinarians. Procedures--Practitioners were invited to participate in a survey involving clinical scenarios of canine cancer patients, offered online and in paper format from October 2010 through January 2011. Analyses identified factors associated with the decision to refer patients to veterinary oncology specialists. Results--1,071 (39.3%) veterinarians responded, of which 603 (56.3%) recommended referral for dogs with multicentric lymphoma and appendicular osteosarcoma. Most (893/1,059 [84.3%]) practiced within < 2 hours' drive of a specialty referral center, and most (981/1,047 [93.7%]) were completely confident in the oncology service. Few (230/1,056 [21.8%] to 349/1,056 [33.0%D were experienced with use of chemotherapeutics, whereas more (627/1,051 [59.7%]) were experienced with amputation. Referral was associated with practitioner perception of patient health status (OR, 1.54; 95% confidence interval [CI], 1.15 to 2.07), the interaction between the client's bond with the dog and the client's financial status, practitioner experience with treating cancer (OR, 2.79; 95% CI, 1.63 to 4.77), how worthwhile practitioners considered treatment to be (OR, 1.66 to 3.09; 95% CI, 1.08 to 4.72), and confidence in the referral center (OR, 2.20; 95% CI, 1.11 to 4.34). Conclusions and Clinical Relevance--Several factors influenced practitioner decisions to refer dogs with lymphoma or osteosarcoma for specialty care. Understanding factors that influence these decisions may enable practitioners to appraise their referral decisions and ensure they act in the best interests of patients, clients, and the veterinary profession. (J Am Vet Med Assoc 2013;243:1415-1425) [ABSTRACT FROM AUTHOR]

Background: Esophageal neoplasms are rarely reported in cats. The frequency rate is less than 0.5% and those neoplasms are usually malignant. Esophageal squamous cell carcinoma (SCC) is an idiopathic epithelial neoplasm, invasive and metastatic that can induce partial or complete obstruction of the esophageal lumen. There is no breed or sex predisposition, and it is more common in cats over 8-years-old. Esophageal SCC is more frequent in the middle third of the esophagus. The prognosis is poor, as the cats are usually diagnosed at an advanced stage. This report aims to describe clinical, endoscopic, radiographic, and pathological features of two cases of esophageal squamous cell carcinoma in cats. Cases: A 11-year-old neutered male cat presenting regurgitation, weight loss, anorexia and dyspnea was referred to veterinary internal medicine care. Simple and contrast-enhanced radiographic images of the cervical and thoracic regions showed an alveolar pattern in the cranial lung lobes and signs of esophageal lumen irregularity and dilatation in the mediastinum topography. The upper digestive endoscopy showed a dilated esophageal lumen, and an irregular mass was observed in the thoracic esophagus involving the entire esophageal circumference. Biopsy fragments were collected, and the histopathological result was compatible with squamous cell carcinoma. The second case was a 10-year-old neutered male cat presenting hyporexia, regurgitation, dyspnea, tachypnea, and abnormal breath sounds. The ultrasound of the chest showed 3 amorphous hypoechogenic and heterogeneous areas in the right and left hemithorax between parietal and visceral pleura. The cytological examination was compatible with a malignant epithelial tumor. The patient died 3 months after the onset of clinical signs. At gross exam, it was observed a friable, irregular, and ulcerated mass of 5.0 x 3.0 cm in the middle third of the esophagus. Metastatic foci in the lungs and liver were also observed. The histopathological diagnosis was esophageal squamous cell carcinoma, with metastases to liver and lungs. Microscopically, in both cases, were seen a proliferation of polyhedral epithelial cells in the mucosa, arranged in nests or trabeculae with central keratinization. These cells presented oval to rounded nuclei, loose chromatin, prominent nucleolus, and abundant eosinophilic cytoplasm, with marked anisocytosis and anisokaryosis, supported by a thin fibrovascular stroma. In the second cat the neoplastic cells infiltrated the esophageal submucosa, including lymphatic vessels and muscle layer. Lung and liver metastases from the SCC had a cellular pattern similar to the primary neoplasm. Discussion: Esophageal squamous cell carcinoma is extremely rare in cats. The SCC begins in the squamous layer of the mucosa and can infiltrate the muscular layer or protrude into the esophageal lumen, leading to clinical signs, as seen in these 2 cats. The differential diagnoses for esophageal SCC include foreign bodies, esophageal strictures, and infiltrative or compressive non-esophageal tumors. Although uncommon, esophageal tumors should be considered when evaluating elderly cats with regurgitation and weight loss. The diagnosis of esophageal SCC was confirmed by histopathological findings collected endoscopically or during necropsy. As noted in both cases, the prognosis of SCC is generally unfavorable, usually due to the difficulty in treatment and diagnosis in a late stage of the disease. [ABSTRACT FROM AUTHOR]

The aim of this study was to observe the effectiveness of treatment with radical pinnectomy and investigate postoperative relapse cases in pinnal squamous cell carcinoma in cats. Twelve cats which were brought to surgery clinic of Istanbul University, Faculty of Veterinary Medicine were used. Biopsies were taken from the cases in which squamous cell carcinoma was suspected following anamnesis and the clinical examination of patients that were brought to our clinic. The patients were diagnosed on the basis of histopathological analysis of biopsy samples. Haemogram and biochemical blood analysis were performed and thoracic radiographs were taken as routine in cases that a decision was made to operate. After the area was prepared for operation radical pinnectomy or total external acoustic canal ablation along with radical pinnectomy were performed in the patients that were eligible for operation. Relapses seen in the postoperative period were re-operated with the techniques selected according to invasion status. Periodic controls of the patients were made after the operations and the cats were examined for relapse. In seven out of 12 cases, only squamous cell carcinoma; in three cases, actinic dermatitis actinic dermatitis in addition to squamous cell carcinoma, and in two cases, only actinic dermatitis lesions were detected. In the postoperative period, relapse was observed in the cases in which the squamous cell carcinoma lesion reached the lower half of the pinna or the external acoustic canal while relapse was not observed in cases with actinic dermatitis lesions or when the squamous cell carcinoma lesion was on the top part of the pinna. Relapse cases were re-operated using different operative techniques. It is concluded that performing radical pinnectomy on actinic dermatitis lesions detected on the pinna before development into squamous cell carcinoma, and removing the tumour according to its localization with radical pinnectomy or total external acoustic canal ablation alongside radical pinnectomy is the most reliable treatment option in terms of relapse in cases of pinnal squamous cell carcinoma. [ABSTRACT FROM AUTHOR]

The objective of this paper was to evaluate the efficacy of a hypofractionated radiation protocol for feline facial squamous cell carcinoma (SCC). Twenty-five histologically confirmed SCCs in 15 cats were treated with four fractions of 7.6–10Gy each, with 1 week intervals. The equipment used was a linear accelerator Clinac 2100 delivering electron beam of 4 or 6MeV, and a bolus of 5 or 10mm was used in all lesions. Of the lesions, 44% were staged as T4, 16% as T3, 8% as T2 and 32% as T1. Of the irradiated lesions, 40% had complete response, 12% had partial response and 48% had no response (NR) to the treatment. For T1 tumors, 62.5% had complete remission. Mean overall survival time was 224 days. Owners requested euthanasia of cats having NR to the treatment. Mean disease free time was 271 days. Side effects observed were skin erythema, epilation, ulceration and conjunctivitis, which were graded according to Veterinary Radiation Therapy Oncology Group (VRTOG) toxicity criteria. Response rates found in this study (52%) were lower when compared to other protocols, probably due to technique differences, such as fractionation schedule, bolus thickness and energy penetration depth. However, the hypofractionated radiation protocol was considered safe for feline facial SCC. Modifications of this protocol are being planned with the objective of improving the cure rates in the future. [Copyright &y& Elsevier]

Among the tumors, skin tumors are seen most frequently in veterinary medicine. The infundibular keratinizing acantoma (IKA) is the less common tumor of the follicular neoplasms, in contrast, mastocytoma (CM) is the most common tumor of mesenchymal tumors in dogs as well as a canine mammary tumors are the most common tumors in female (25 to 50% of all tumors) being malignant 41 to 50 per cent of them. This paper seeks to document the findings of anatomopathology and presentation of three rare cutaneous neoplasms in a female dog. A case of a canine, female, 11 years old, poodle cross breed that was remitted to consultation by emesis 15 days ago and the presence of masses in the abdomen and mammary gland. The patient was euthanized. The autopsy showed multiple rounded masses of varying sizes in the skin of the abdomen and mammary glands and in the parenchyma of the spleen and liver. The tissue samples were fixed in 10% buffered formalin and taken to the laboratory for routine histological processing. It was diagnosed complex mammary carcinoma, a metastatic type III CM and IKA. It was showed two malignant tumors and one benign skin tumor in the same animal and was reported the simultaneous and infrequent appearance of the CM associated with IKA. [ABSTRACT FROM AUTHOR]

In this paper the design and use of a semi-quantitative real-time polymerase chain reaction assay (RT-PCR) for feline leukaemia virus (FeLV) provirus is described. Its performance is evaluated against established methods of FeLV diagnosis, including virus isolation and enzyme-linked immunoassay (ELISA) in a population of naturally infected cats. The RT-PCR assay is found to have both a high sensitivity (0.92) and specificity (0.99) when examined by expectation maximisation methods and is also able to detect a large number of cats with low FeLV proviral loads that were negative by other conventional test methods. [Copyright &y& Elsevier]

Background: Physical exercise is suspected to reduce cancer risk and mortality. So far, little is known about the underlying mechanisms. Although limited, murine models represent a promising attempt in order to gain knowledge in this field. Objective: A systematic review and meta-analysis examining various treatment protocols was conducted in order to determine the impact of exercise on tumor growth in rodents. Methods: PubMed, Google scholar and System for information on Gray literature in Europe were screened from inception to October 2017. Risk of bias within individual studies was assessed using the Office of Health Assessment and Translation risk of bias rating tool for human and animal trials. The effect of exercise on tumor growth over and above non-exercise control was pooled using random-effects model. Subgroup analyses were conducted to identify potential moderators. Results: The quality of the included 17 articles ranged between "probably low" and "high risk of bias." A significant reduction in tumor growth in exercising animals compared to controls was detected (Hedges' g = −0.40; 95% CI −0.66 to −0.14, p < 0.01) with between-study heterogeneity (τ2 = 0.217, I 2 = 70.28%, p < 0.001). The heterogeneity was partially explained by three moderators representing the in-between group differences of "maximum daily exercise" R 2 = 33% (p < 0.01), "type of cancer administration" R 2 = 28% (p < 0.05), and "training initiation" R 2 = 27% (p < 0.05). Conclusion: This meta-analysis suggests that physical exercise leads to reduction of tumor size in rodents. Since "maximum daily exercise" was found to have at least modest impact on tumor growth, more clinical trials investigating dose-response relationships are needed. [ABSTRACT FROM AUTHOR]

Background: Currently no methods are available to predict the clinical outcome of individual horses with equine sarcoid (ES) disease. Objective: To investigate if whole blood microRNA (miRNA) profiles can predict the long‐term development of ES tumors. Animals Five horses with regression and 5 with progression of ES lesions monitored over 5‐7 years and 5 control horses free of ES for at least 5 years. Methods: For this cohort study, RNA extracted from whole blood samples from the regression, progression, and control groups was used for high throughput sequencing. Known and novel miRNAs were identified using miRDeep2 and differential expression analysis was carried out by the DESeq2 algorithm. Target gene and pathway prediction as well as enrichment and network analyses were conducted using TarBase, mirPath, and metaCore from GeneGo. Results: Fourteen miRNAs were differentially expressed between regression and progression groups after accounting for the control condition: 4 miRNAs (28.6%) were upregulated and 10 miRNAs (71.4%) were downregulated with >2‐fold change. Seven of the 10 downregulated miRNAs are encoded in an miRNA cluster on equine chromosome 24, homologous to the well‐known 14q32 cluster in humans. Their target genes show enrichment for pathways involved in viral carcinogenesis. Conclusions and Clinical Importance: Whole blood miRNA expression profiles are associated with long‐term ES growth in horses and warrant further validation as prognostic biomarkers in a larger study cohort. Deregulation of miRNAs on equine chromosome 24 might represent a trigger for ES development. [ABSTRACT FROM AUTHOR]

Five cases of hemangiosarcoma were documented in three tigers and two lions during post-mortem examinations. Grossly, reddish-black coloured elevated masses were noticed with metastasis to the spleen. In one tiger, an enlarged liver with severe oozing of blood on a cut section was noticed without any elevated masses. In a white tiger, the tumour mass was located near the abdominal region. Histopathological features revealed the presence of immature plump endothelial cells forming blood filled irregular vascular spaces. Immunohistochemically, strong immunoreactivity in the cytoplasm of neoplastic endothelial cells with vascular endothelial growth factor (VEGF) was noticed. No positive reaction was noticed with the proliferative markers, i.e., Ki67 and p53, indicating VEGF is the appropriate marker to diagnose hemangiosarcoma. [ABSTRACT FROM AUTHOR]

NIH 3T3 cells grown in conventional Dulbecco's modification of Eagle's basal medium (DME) produce no transformed foci when grown to confluence in 10% calf serum (CS). A few cultures were transformed by ras oncogenes when transfected with DNA from neoplastic cells, but they failed to do so in 80 to 90% of the transfections. However, when they were grown in a medium [molecular, cellular, and developmental biology 402 (MCDB 402)] optimized for their clonal growth in minimal serum, they produced transformed foci without transfection in 10% CS, but not in 2% CS. The first response to growth in MCDB 402 in 2% CS in successive rounds of contact inhibition was uniform increases in saturation density of the population. This was followed by the appearance of transformed foci. A systematic study was made of the dynamics of neoplastic progression in various concentrations of CS in a single round of confluence at 2 and 3 wk, followed by three sequential rounds of confluence in 2% CS for 2 wk. There was a linear relationship between CS concentration and saturation density in the first-round cultures and continuing differences in subsequent cultures. The hyperplastic field of normal-looking cells surrounding transformed foci became increasingly permissive for transformation with serial culture. The dynamics show that epigenetic selection is the major driving force of neoplastic development. Cells from dense foci produced malignant fibrosarcomas in mice, thereby exhibiting a positive relationship between transformation in culture and the development of tumors. [ABSTRACT FROM AUTHOR]

The flap method of horn amputation was performed in nineteen (19) bovines (13 cases of horn fracture and 06 cases of horn cancer). The technique provided adequate closure of horn base. Post-operatively, the animals served their utility without any complications. [ABSTRACT FROM AUTHOR]

Large animals should have higher lifetime probabilities of cancer than small animals because each cell division carries an attendant risk of mutating towards a tumour lineage. However, this is not observed—a (Peto's) paradox that suggests large and/or long-lived species have evolved effective cancer suppression mechanisms. Using the Euler-Lotka population model, we demonstrate the evolutionary value of cancer suppression as determined by the 'cost' (decreased fecundity) of suppression verses the 'cost' of cancer (reduced survivorship). Body size per se will not select for sufficient cancer suppression to explain the paradox. Rather, cancer suppression should be most extreme when the probability of non-cancer death decreases with age (e.g. alligators), maturation is delayed, fecundity rates are low and fecundity increases with age. Thus, the value of cancer suppression is predicted to be lowest in the vole (short lifespan, high fecundity) and highest in the naked mole rat (long lived with late female sexual maturity). The life history of pre-industrial humans likely selected for quite low levels of cancer suppression. In modern humans that live much longer, this level results in unusually high lifetime cancer risks. The model predicts a lifetime risk of 49% compared with the current empirical value of 43%. [ABSTRACT FROM AUTHOR]

Leucine-rich glioma-inactivated ( LGI) protein was first thought to have a suppressor effect in the formation of some cancers. Developments in physiology and medicine made it possible to characterize the function of the LGI protein family and its crucial role in different conditions more precisely. These proteins play an important role in synaptic transmission, and dysfunction may cause hyperexcitability. Genetic mutation of LGI1was confirmed to be the cause of autosomal dominant lateral temporal lobe epilepsy in humans. The LGI2 mutation was identified in benign familial juvenile epilepsy in Lagotto Romagnolo ( LR) dogs. Cats with familial spontaneous temporal lobe epilepsy have been reported, and the etiology might be associated with LGI protein family dysfunction. In addition, an autoimmune reaction against LGI1 was detected in humans and cats with limbic encephalitis. These advances prompted a review of LGI protein function and its role in different seizure disorders. [ABSTRACT FROM AUTHOR]

We devised an aerosol based demethylation therapy to achieve therapeutic efficacy in premalignant or in situ lesions of lung cancer, without systemic toxicity. Optimum regimens of aerosolized azacytidine (Aza) were designed and used in orthotopic human non-small cell lung cancer xenograft models. The therapeutic efficacy and toxicity of aerosol Aza were compared with intravenously administered Aza. We observed that 80% of the droplets of the aerosol Aza measured ∼0.1–5 microns, which resulted in deposition in the lower bronchial airways. An animal model that phenocopies field carcinogeneisis in humans was developed by intratracheal inoculation of the human lung cancer cells in mice, thus resulting in their distribution throughout the entire airway space. Aerosolized Aza significantly prolonged the survival of mice bearing endo-bronchial lung tumors. The aerosol treatment did not cause any detectable lung toxicity or systemic toxicity. A pre-pharmacokinetic study in mice demonstrated that lung deposition of aerosolized Aza was significantly higher than the intravenous route. Lung tumors were resected after aerosol treatment and the methylation levels of 24 promoters of tumor-suppresser genes related to lung cancer were analyzed. Aerosol Aza significantly reduced the methylation level in 9 of these promoters and reexpressed several genes tested. In conclusion, aerosol Aza at non-cytotoxic doses appears to be effective and results in DNA demethylation and tumor suppressor gene re-expression. The therapeutic index of aerosol Aza is >100-fold higher than that of intravenous Aza. These results provide a preclinical rationale for a phase I clinical trial of aerosol Aza to be initiated at our Institution. [ABSTRACT FROM AUTHOR]

Background: One of the most popular and versatile model of murine melanoma is by inoculating B16 cells in the syngeneic C57BL6J mouse strain. A characterization of different B16 modified cell sub-lines will be of real practical interest. For this aim, modern analytical tools like surface enhanced Raman spectroscopy/scattering (SERS) and MTT were employed to characterize both chemical composition and proliferation behavior of the selected cells. Methods: High quality SERS signal was recorded from each of the four types of B16 cell sub-lines: B164A5, B16GMCSF, B16FLT3, B16F10, in order to observe the differences between a parent cell line (B164A5) and other derived B16 cell sub-lines. Cells were incubated with silver nanoparticles of 50-100 nm diameter and the nanoparticles uptake inside the cells cytoplasm was proved by transmission electron microscopy (TEM) investigations. In order to characterize proliferation, growth curves of the four B16 cell lines, using different cell numbers and FCS concentration were obtained employing the MTT proliferation assay. For correlations doubling time were calculated. Results: SERS bands allowed the identification inside the cells of the main bio-molecular components such as: proteins, nucleic acids, and lipids. An "on and off" SERS effect was constantly present, which may be explained in terms of the employed laser power, as well as the possible different orientations of the adsorbed species in the cells in respect to the Ag nanoparticles. MTT results showed that among the four tested cell sub-lines B16 F10 is the most proliferative and B164A5 has the lower growth capacity. Regarding B16FLT3 cells and B16GMCSF cells, they present proliferation ability in between with slight slower potency for B16GMCSF cells. Conclusion: Molecular fingerprint and proliferation behavior of four B16 melanoma cell sub-lines were elucidated by associating SERS investigations with MTT proliferation assay. [ABSTRACT FROM AUTHOR]

Background: Papillomaviruses (PVs) are highly epitheliotropic as they usually establish productive infections within squamous epithelia of the skin, the anogenital tract and the oral cavity. In this study, early (E) and late (L) protein expression of bovine papillomavirus type 2 (BPV-2) in the urothelium of the urinary bladder is described in cows and water buffaloes suffering from naturally occurring papillomavirus-associated urothelial bladder tumors. Methods and Findings: E5 protein, the major oncoprotein of the BPV-2, was detected in all tumors. L1 DNA was amplified by PCR, cloned and sequenced and confirmed to be L1 DNA. The major capsid protein, L1, believed to be only expressed in productive papillomavirus infection was detected by Western blot analysis. Immunohistochemical investigations confirmed the presence of L1 protein both in the cytoplasm and nuclei of cells of the neoplastic urothelium. Finally, the early protein E2, required for viral DNA replication and known to be a pivotal factor for both productive and persistent infection, was detected by Western blot and immunohistochemically. Electron microscopic investigations detected electron dense particles, the shape and size of which are consistent with submicroscopic features of viral particles, in nuclei of neoplastic urothelium. Conclusion: This study shows that both active and productive infections by BPV-2 in the urothelium of the bovine and bubaline urinary bladder can occur in vivo. [ABSTRACT FROM AUTHOR]

An adult male Australian parakeet (Melopsittacus undulatus) presented a firm nodular lesion in the lateral metacarpal region of the right wing. Microscopically, there were neoplastic cells, round and polyhedral in shape, with abundant, slightly eosinophilic granular cytoplasm; they were strongly periodic-acid Schiff-positive and resistant to diastase digestion. Some groups of neoplastic cells were immunopositive for smooth muscle actin and desmin. There was no immunopositivity for S-100 protein, CD68 and cytokeratin. Ultrastructurally, the neoplastic cells were round and polygonal in shape, and they were characterized by abundant cytoplasm with numerous homogeneous osmophilic bodies covered by an electron-dense membrane (lysosomes). The histopathologic, immunohistochemical and ultrastructural features of the neoplastic tissue are consistent with a granular cell tumour, which has been described in different animal species and anatomic locations; however, this seems to be an infrequent neoplasm in Australian parakeets. The immunopositivity of the neoplastic cells for smooth muscle actin and desmin, as well as slight positivity for muscle with Masson's trichrome, suggest that this is a tumour of myogenic origin. [ABSTRACT FROM AUTHOR]

Objectives: Zornia diphylla (L.) Pers is an ethnomedical herb. The aim of the study is to scientifically verify the traditional use of Z. diphylla as an anticancer medicine. Materials and Methods: Different extracts, fractions, and chemical isolates of the whole plant were screened for cytotoxicity to Dalton's lymphoma ascites (DLA) cells by the Trypan blue exclusion method and MTT assay. Column chromatographic and preparative TLC techniques were used for the isolation of active fraction (AF) and active principle. Cytotoxicity of AF to different cell types was tested. The apoptotic activity of AF was evaluated by morphological observations, nuclear condensation, and comet assay. In vivo antitumor activity of AF was determined in DLA-challenged mice. Short-term (29 days) preliminary toxicity evaluation of AF was done in mice. Results: n-Hexane extract (but not water and ethanol extracts) showed significant cytotoxicity. AF, isolated from n-hexane extract, induced apoptotic cell death (in vitro) to DLA cells, but not to normal thymocytes and macrophages. A steroid positive active principle was isolated which showed 100% cytotoxicity at 5 μg/mL level. Interestingly, AF (50 mg/kg) protected all the mice challenged with one million DLA cells/mouse. AF (up to 10 times higher than the therapeutic dose) did not exhibit any conspicuous adverse toxic symptoms in the toxicity evaluation. Conclusion: Z. diphylla (AF) showed promising in vitro and in vivo anticancer activity against DLA cells, and it was devoid of any toxicity to mice in short-term toxicity evaluation. The herb is promising for the development of a valuable anticancer medicine. [ABSTRACT FROM AUTHOR]

The Tasmanian devil (Sarcophilus harrisii), the world's largest marsupial carnivore, is under threat of extinction following the emergence of an infectious cancer. Devil facial tumour disease (DFTD) is spread between Tasmanian devils during biting. The disease is consistently fatal and devils succumb without developing a protective immune response. The aim of this study was to determine if Tasmanian devils were capable of forming cytotoxic antitumour responses and develop antibodies against DFTD cells and foreign tumour cells. The two Tasmanian devils immunised with irradiated DFTD cells did not form cytotoxic or humoral responses against DFTD cells, even after multiple immunisations. However, following immunisation with xenogenic K562 cells, devils did produce cytotoxic responses and antibodies against this foreign tumour cell line. The cytotoxicity appeared to occur through the activity of natural killer (NK) cells in an antibody dependent manner. Classical NK cell responses, such as innate killing of DFTD and foreign cancer cells, were not observed. Cells with an NK-like phenotype comprised approximately 4 percent of peripheral blood mononuclear cells. The results of this study suggest that Tasmanian devils have NK cells with functional cytotoxic pathways. Although devil NK cells do not directly recognise DFTD cancer cells, the development of antibody dependent cell-mediated cytotoxicity presents a potential pathway to induce cytotoxic responses against the disease. These findings have positive implications for future DFTD vaccine research. [ABSTRACT FROM AUTHOR]

Hemangiosarcoma (HSA) is a common malignancy of dogs with characteristic early, aggressive metastasis. Diagnosis of HSA is challenging because of lack of sensitive and specific diagnostic tests. Specific proteins that are increased in serum of dogs with HSA might represent useful biomarkers of the disease. Thirty-four dogs with HSA and 42 healthy dogs from the Ontario Veterinary College Teaching Hospital. This case-control study compared serum proteins in dogs with HSA and healthy dogs. Proteins were separated by 2-dimensional difference gel electrophoresis and identified by liquid chromatography and tandem mass spectrometry. Western blot analysis showed that serum collagen XXVII peptide concentration in serum of dogs with large metastatic HSA burdens (1,488, 231 -3,754 DU; median, minimum-maximum); was, on average, 9.5-fold higher than in healthy dogs (156; 46-2,101 DU). While concentrations for dogs with osteosarcomas (678; 124-3,251 DU), lymphomas (423; 92-2,777 DU), carcinomas (1,022; 177-3,448 DU), and inflammatory disease were also increased, values were consistently lower than those for HSA. Receiver operating characteristic curves revealed an estimated area under the curve of 83% for HSA cases whereas areas for other neoplastic and nonneoplastic diseases were nondiscriminatory. Serum collagen XXVII peptide concentration before splenectomy (1,350; 1,156-1,929 DU) was reduced after tumor removal (529; 452-562 DU) and chemotherapy but increased in 2 dogs with tumor recurrence (511-945 DU; 493-650 DU). Collagen XXVII peptide might be useful for diagnosis and monitoring of advanced HSA. [ABSTRACT FROM AUTHOR]

Identification of biomarkers that predict outcomes in dogs with osteosarcoma (OSA) would be valuable to veterinarians and owners. Leukocyte numbers in peripheral blood are associated with outcomes in some types of cancer in humans. We hypothesized that increased numbers of monocytes would be associated with reduced disease-free interval (DFI) in dogs with OSA. Medical data from 69 dogs with appendicular OSA treated with amputation and chemotherapy were selected for study. Retrospective study. Statistical associations were assessed by univariate and multivariate analysis. Information about DFI and leukogram values, tumor location, and serum alkaline phosphatase was abstracted from the medical record. Higher numbers of circulating monocytes (>0.4 × 10 cells/μL) and lymphocytes (>1.0 × 10 cells/μL) before treatment were found to be significantly ( P < .05) associated with shorter DFI in dogs with OSA. Other parameters associated with poor outcomes were increased alkaline phosphatase, primary tumor location, and age. These results indicated that pretreatment evaluation of monocyte and lymphocyte counts provided prognostic information for dogs with appendicular OSA. Notably, most animals in this study had monocyte counts within the normal reference range, indicating that variations within the reference range of leukocyte values might also have prognostic significance. [ABSTRACT FROM AUTHOR]

Background: Signaling through the mTOR pathway contributes to growth, progression and chemoresistance of several cancers. Accordingly, inhibitors have been developed as potentially valuable therapeutics. Their optimal development requires consideration of dose, regimen, biomarkers and a rationale for their use in combination with other agents. Using the infrastructure of the Comparative Oncology Trials Consortium many of these complex questions were asked within a relevant population of dogs with osteosarcoma to inform the development of mTOR inhibitors for future use in pediatric osteosarcoma patients. Methodology/Principal Findings: This prospective dose escalation study of a parenteral formulation of rapamycin sought to define a safe, pharmacokinetically relevant, and pharmacodynamically active dose of rapamycin in dogs with appendicular osteosarcoma. Dogs entered into dose cohorts consisting of 3 dogs/cohort. Dogs underwent a pre-treatment tumor biopsy and collection of baseline PBMC. Dogs received a single intramuscular dose of rapamycin and underwent 48- hour whole blood pharmacokinetic sampling. Additionally, daily intramuscular doses of rapamycin were administered for 7 days with blood rapamycin trough levels collected on Day 8, 9 and 15. At Day 8 post-treatment collection of tumor and PBMC were obtained. No maximally tolerated dose of rapamycin was attained through escalation to the maximal planned dose of 0.08 mg/kg (2.5 mg/30kg dog). Pharmacokinetic analysis revealed a dose-dependent exposure. In all cohorts modulation of the mTOR pathway in tumor and PBMC (pS6RP/S6RP) was demonstrated. No change in pAKT/AKT was seen in tumor samples following rapamycin therapy. Conclusions/Significance: Rapamycin may be safely administered to dogs and can yield therapeutic exposures. Modulation pS6RP/S6RP in tumor tissue and PBMCs was not dependent on dose. Results from this study confirm that the dog may be included in the translational development of rapamycin and potentially other mTOR inhibitors. Ongoing studies of rapamycin in dogs will define optimal schedules for their use in cancer and evaluate the role of rapamycin use in the setting of minimal residual disease. [ABSTRACT FROM AUTHOR]

Background: 'Intrinsic' resistance to retroviral infection was first recognised with the Friend virus susceptibility gene (Fv1), which determines susceptibility to murine leukaemia virus (MLV) infection in different murine species. Similarly, the tripartite motif (TRIM) family of proteins determine lentiviral restriction in a primate host-species specific manner. For example rhesus TRIM5α (rhTRIM5α) can potently restrict HIV-1 infection while human TRIM5α (huTRIM5α) only has a mild effect on SIVmac and HIV-1 infectivity (Lv1). Human TRIM5α is able to restrict MLV-N virus replication, but is ineffective against MLV-B or MLV-NB virus infection. Lv2 restriction of some HIV-2 viruses is seen in human cells. Like Lv1, Lv2 is a post-entry restriction factor, whose viral determinants have been mapped to the viral capsid (CA). Unlike Lv1, however, Lv2 is determined by envelope (Env) in addition to CA. Here we present evidence of a novel Env determined post entry restriction to infection in human cells of pseudotyped MLV-B and MLV-NB cores. Results: We generated retroviral vectors pseudotyped with various gamma and lentiviral Envs on MLV-B and -NB CAs containing a green fluorescent protein (GFP) reporter. Flow cytometry was used to determine transduction efficiencies in NP2/CD4/CXCR4 (glioma cell line stably transduced with the HIV receptors) and HeLa/CD4 cell lines. The HeLa/CD4 cell line restricted both MLV CAs in an Env dependent manner, compared to NP2/CD4/CXCR4 cells. Quantitative polymerase chain reaction (QT-PCR) analysis of reverse transcription (RT) transcripts demonstrates that this restriction occurs at a post entry and RT level. siRNA knockdown of huTRIM5α ruled out a direct role for this cellular component in mediating this restriction. We describe a previously unobserved Env determined restriction of MLV-B and MLV-NB CAs in HeLa/CD4 cells when pseudotyped with HIV-2 and RD114 Envs, but not gibbon ape leukaemia virus (GALV), HIV-1 or Amphotrophic (Ampho) Envs. Conclusions: Our data further demonstrate the variability of Env and CA mediated susceptibility to post entry host cell restriction. We discuss the relevance of these findings in light of the growing evidence supporting the complexities involved in innate host immunity to retroviral infection. [ABSTRACT FROM AUTHOR]

The article provides information on how to distinguish canine cutaneous mast cell tumours in dogs that make a real hazard from tumours which can be handled with less caution. It states that mast cell tumours categorised in three groups to know which react favourably to surgery including the curable by complicated surgery, simple surgery, and not treated. It also cites the updates to help practitioners to distinguish the three groups including signs presentation, fine needle aspirate, and biopsy.

Background: Prostate cancer is a frequent finding in man. In dogs, malignant disease of the prostate is also of clinical relevance, although it is a less common diagnosis. Even though there are numerous differences in origin and development of the disease, man and dog share many similarities in the pathological presentation. For this reason, the dog might be a useful animal model for prostate malignancies in man. Although prostate cancer is of great importance in veterinary medicine as well as in comparative medicine, there are only few cell lines available. Thus, it was the aim of the present study to determine whether the formerly established prostate carcinoma cell line CT1258 is a suitable tool for in vivo testing, and to distinguish the growth pattern of the induced tumours. Methods: For characterisation of the in vivo behaviour of the in vitro established canine prostate carcinoma cell line CT1258, cells were inoculated in 19 NOD.CB17-PrkdcScid/J (in the following: NOD-Scid) mice, either subcutaneously or intraperitoneally. After sacrifice, the obtained specimens were examined histologically and compared to the pattern of the original tumour in the donor. Cytogenetic investigation was performed. Results: The cell line CT 1258 not only showed to be highly tumourigenic after subcutaneous as well as intraperitoneal inoculation, but also mimicked the behaviour of the original tumour. Conclusion: Tumours induced by inoculation of the cell line CT1258 resemble the situation in naturally occurring prostate carcinoma in the dog, and thus could be used as in vivo model for future studies. [ABSTRACT FROM AUTHOR]

Oncogenic wingless-related mouse mammary tumour virus (Wnt) signalling, caused by epigenetic inactivation of specific pathway regulators like the putative tumour suppressor secreted frizzled-related protein 1 (SFRP1), may be causally involved in the carcinogenesis of many human solid tumours including breast, colon and kidney cancer. To evaluate the incidence of SFRP1 deficiency in human tumours, we performed a large-scale SFRP1 expression analysis using immunohistochemistry on a comprehensive tissue microarray (TMA) comprising 3448 tumours from 36 organs. This TMA contained 132 different tumour subtypes as well as 26 different normal tissues. Although tumour precursor stages of, for example kidney, colon, endometrium or adrenal gland still exhibited moderate to abundant SFRP1 expression, this expression was frequently lost in the corresponding genuine tumours. We defined nine novel tumour entities with apparent loss of SFRP1 expression, i.e., cancers of the kidney, stomach, small intestine, pancreas, parathyroid, adrenal gland, gall bladder, endometrium and testis. Renal cell carcinoma (RCC) exhibited the highest frequency of SFRP1 loss (89% on mRNA level; 75% on protein level) and was selected for further analysis to investigate the cause of SFRP1 loss in human tumours. We performed expression, mutation and methylation analysis in RCC and their matching normal kidney tissues. SFRP1 promoter methylation was frequently found in RCC (68%, n=38) and was correlated with loss of SFRP1 mRNA expression (p<0.05). Although loss of heterozygosity was found in 16% of RCC, structural mutations in the coding or promoter region of the SFRP1 gene were not observed. Our results indicate that loss of SFRP1 expression is a very common event in human cancer, arguing for a fundamental role of aberrant Wnt signalling in the development of solid tumours. In RCC, promoter hypermethylation seems to be the predominant mechanism of SFRP1 gene silencing and may contribute to initiation and progression of this disease.Oncogene (2007) 26, 5680–5691; doi:10.1038/sj.onc.1210345; published online 12 March 2007 [ABSTRACT FROM AUTHOR]

Larger organisms have more potentially carcinogenic cells, tend to live longer and require more ontogenic cell divisions. Therefore, intuitively one might expect cancer incidence to scale with body size. Evidence from mammals, however, suggests that the cancer risk does not correlate with body size. This observation defines "Peto' paradox." Here, we propose a novel hypothesis to resolve Peto's paradox. We suggest that malignant tumors are disadvantaged in larger hosts. In particular, we hypothesize that natural selection acting on competing phenotypes among the cancer cell population will tend to favor aggressive "cheaters" that then grow as a tumor on their parent tumor, creating a hypertumor that damages or destroys the original neoplasm. In larger organisms, tumors need more time to reach lethal size, so hypertumors have more time to evolve. So, in large organisms, cancer may be more common and less lethal. We illustrate this hypothesis in silico using a previously published hypertumor model. Results from the model predict that malignant neoplasms in larger organisms should be disproportionately necrotic, aggressive, and vascularized than deadly tumors in small mammals. These predictions may serve as the basis on which to test the hypothesis, but to our knowledge, no one has yet performed a systematic investigation of comparative necrosis, histopathology, or vascularization among mammalian cancers. [ABSTRACT FROM AUTHOR]

Jaagsiekte sheep retrovirus (JSRV) causes a contagious lung cancer in sheep and goats, with significant animal health and economic consequences. The host range of JSRV is in part limited by species-specific differences in the virus entry receptor, hyaluronidase 2 (Hyal2), which is not functional as a receptor in mice but is functional in humans. Sheep are immunotolerant of JSRV because of the expression of closely related endogenous retroviruses, which are not present in humans and most other species, and this may facilitate oncogenesis. Here we show that expression of the JSRV envelope (Env) protein alone in lungs of mice, by using a replication-incompetent adeno-associated virus vector, results in tumours with a bronchiolo-alveolar localization like those seen in sheep. Whereas lethal disease was observed in immunodeficient mice, tumour development was almost entirely blocked in immunocompetent mice. Our results provide a rare example of an oncogenic viral structural protein, show that interaction of the viral Env protein with the virus entry receptor Hyal2 is not required for tumorigenesis, and indicate that immune recognition of Env can protect against JSRV tumorigenesis. [ABSTRACT FROM AUTHOR]

The authors comment on a study that identified cancer modifier genes, quantitative trait loci (QTLs) that change cancer development in rodents. They mention compelling motivations for the study, including the expectation that the genes underlying the QTLs will provide paradigms for understanding genetic variation in human cancer risk. The starting point for most cancer QTL studies, the authors claim, is the observation of significant variation in cancer risk among inbred strains.

A response from the authors of the research "Initial case reports of cancer in naked mole-rats (Heterocephalus glaber)" is presented.

The article discusses a workshop held by the Institute of Medicine's National Cancer Policy Board in June 2015 in Washington DC on the topic "The Role of Clinical Studies for Pets with Naturally Occurring Tumors in Translational Cancer Research." It notes how dogs develop cancers that share many characteristics with human disease such as long latency periods and cites the 10-year Golden Retriever Lifetime Study which may yield genetic clues on why this breed experiences high rate of cancer.

A jersey crossbred cow was presented with the history of reduced appetite, drooling of saliva, difficulty in prehension and mastication for past three months. Clinical examination of the mouth revealed a hard swelling of lower gum jaw in the rostral region with the incisors placed apart. Haemogram showed marginal leukocytosis and radiological examination of the lower jaw showed osteolytic changes. Surgical excision of the tumor was performed under sedation and local analgesia. Histomorphological features of the excised mass confirmed it as ameloblastoma. The animal had an uneventful recovery. [ABSTRACT FROM AUTHOR]

The article cites key research findings from London, England in 2006 that links a common canine cancer to a lone Siberian wolf or dog that carried a tumor-producing virus over 250 years ago. The study involved the performance of forensic DNA tests on certain venereal tumors called canine transmissible venereal tumors in 16 dogs and 40 samples.