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Canine osteosarcoma (OS) is an aggressive bone tumor with high metastatic potential and poor prognosis, mainly due to metastatic disease. Nanomedicine-based agents can be used to improve both primary and metastatic tumor treatment. Recently, gold nanoparticles were shown to inhibit different stages of the metastatic cascade in various human cancers. Here, we assessed the potential inhibitory effect of the glutathione-stabilized gold nanoparticles (Au-GSH NPs) on canine OS cells extravasation, utilizing the ex ovo chick embryo chorioallantoic membrane (CAM) model. The calculation of cells extravasation rates was performed using wide-field fluorescent microscopy. Transmission electron microscopy and Microwave Plasma Atomic Emission Spectroscopy revealed Au-GSH NPs absorption by OS cells. We demonstrated that Au-GSH NPs are non-toxic and significantly inhibit canine OS cells extravasation rates, regardless of their aggressiveness phenotype. The results indicate that Au-GSH NPs can act as a possible anti metastatic agent for OS treatment. Furthermore, the implemented CAM model may be used as a valuable preclinical platform in veterinary medicine, such as testing anti-metastatic agents.

Background Diabetes mellitus (DM) often leads to dangerous thromboembolic complications in humans. DM is also a relatively common endocrinopathy of dogs. There is scarce information regarding procoagulant and anticoagulant plasma indicators in this disease. The aim of the study was to evaluate the levels of the selected plasma haemostatic parameters in dogs suffering from diabetes. The study group consisted of 20 dogs meeting all the inclusion criteria, with fasting glycaemia exceeding 11.1 mmol/l. The control group consisted of 15 healthy dogs presented for routine examination. An evaluation of the prothrombin time (PT); and fibrinogen, D-dimer and antithrombin III (ATIII) levels was performed. Results Except for ATIII activity, the haemostatic parameter differences were not statistically significant. High values of ATIII activity were observed in 90% of diabetic dogs. On average, the values amounted to 166.6% and were 31.4% higher than those in the control group. The ATIII activity in the diabetic group was significantly higher than that in the control group (p = 0.0004). Conclusions Here, we report elevated levels of ATIII in diabetic dogs. This finding may suggest the protective role of ATIII against potential thrombotic events. However, the exact role of ATIII in dog diabetes remains unclear.

Osteosarcoma (OSA) is the most common malignant bone neoplasia in humans and dogs. In dogs, treatment consists of surgery in combination with chemotherapy (mostly carboplatin and/or doxorubicin (Dox)). Chemotherapy is often rendered ineffective by multidrug resistance. Previous studies have revealed that Dox conjugated with 4 nm glutathione-stabilized gold nanoparticles (Au-GSH-Dox) enhanced the anti-tumor activity and cytotoxicity of Dox in Dox-resistant feline fibrosarcoma cell lines exhibiting high P-glycoprotein (P-gp) activity. The present study investigated the influence of Au-GSH-Dox on the canine OSA cell line D17 and its relationship with P-gp activity. A human Dox-sensitive OSA cell line, U2OS, served as the negative control. Au-GSH-Dox, compared to free Dox, presented a greater cytotoxic effect on D17 (IC50 values for Au-GSH-Dox and Dox were 7.9 μg/mL and 15.2 μg/mL, respectively) but not on the U2OS cell line. All concentrations of Au-GSH (ranging from 10 to 1000 μg/mL) were non-toxic in both cell lines. Inhibition of the D17 cell line with 100 μM verapamil resulted in an increase in free Dox but not in intracellular Au-GSH-Dox. The results indicate that Au-GSH-Dox may act as an effective drug in canine OSA by bypassing P-gp.

Combination chemiotherapy is the current standard of care for dogs with lymphoma. Multidrug resistance is one of the most important factors contributing to the efficacy of chemiotherapy. The major protein responsible for this phenomenon is P-glycoprotein. Little is known about P-glycoprotein expression in particular subtypes of lymphomas. The aim of the study was evaluation of P-glycoprotein expression in various subtypes of canine lymphomas. Positive reaction with P-glycoprotein was found in 12/25 cases of various morphological subtypes of lymphomas, however, in 3/11 lymphomas the percentage of positively weakly stained cells was

Survivin is a member of apoptosis inhibiting proteins family. Apart from its antiapoptotic activity it plays a critical role in regulating the cell cycle and mitosis. It is overexpressed in most human malignancies. While the prognostic significance of survivin expression is widely investigated in human non-Hodgkin's lymphomas, little is known about its expression in canine lymphomas. The aim of the study was to evaluate the expression of survivin in canine lymphomas in relation to proliferation markers (mitotic index and percentage of Ki67-positive cells). Survivin was found in all examined lymphomas belonging to 6 different morphological subtypes with nuclear immunoreactivity. In most of lymphomas (18/25) survivin expression ranged 10%-25% of positive cells. Only single cases had lower (0-10% positive cells, 1/25) or higher (25-50% and >50% positive cells, 5/25 and 1/25, respectively) index of survivin. Neither mitotic index nor proliferative index correlated with survivin expression when the values quantified randomly in whole specimens were compared. However, when survivin expression were quantified in selected tumor areas of low and high proliferation activity the high correlations between survivin expression and proliferation index were found. The results indicated that survivin is commonly expressed in canine lymphomas. Nuclear labelling together with the relation of its expression and proliferative activity in highly proliferative areas of neoplastic tissue suggest a potential role of survivin in cell cycle activation in canine lymphoma cells. However, further studies of the relation between expression of survivin and other proteins involved in cell cycle regulation are needed. Moreover, the results suggest that survivin may pose the therapeutic target in canine lymphomas.

Background: Cancer remains a leading cause of death in companion animals. In human medicine, liposomes and nanoparticles have been extensively investigated as drug delivery systems (DDS) for anticancer agents due to their ability to target cancerous cells and reduce the negative side effects of free cytostatic drugs. In this review, the authors discuss the results of clinical trials using liposomes and polymer-based nanoparticles as DDS to improve cancer treatment in dogs and cats, indicating which ones seem worth further evaluation. The authors then overview ongoing animal cancer clinical trials, evaluating nano-DDS registered on the American Veterinary Medical Association Animal Health Studies Database. Finally, the authors indicate the nano-drugs that require further in vivo evaluation based on the encouraging results obtained from in vitro studies. Conclusions: Liposomes have been the most investigated nano-DDS in veterinary medicine. The lack of cardiotoxicity of the commercially available liposomal doxorubicin (Doxil/Caelyx) suggests it should be used in dogs with cardiac disorders, rather than using free doxorubicin. Cisplatin-incorporated hyaluronic acid nanoparticles, nanocrystals of cisplatin, and paclitaxel are the most promising nano-drugs for potent applications in treating various canine cancers (e.g. oral melanoma, oral sarcoma, and anal gland adenocarcinoma) and their translation into the treatment of human diseases.

The chick embryo chorioallantoic membrane (CAM) model is extensively used in human medicine in preclinical oncological studies. The CAM model has several advantages: low cost, simple experimental approach, time saving and following “3R principles”. Research has shown that the human osteosarcoma cell lines U2OS, MMNG-HOS, and SAOS can form tumors on the CAM. In veterinary medicine, this has been described only for feline fibrosarcomas, feline mammary carcinomas and canine osteosarcomas. However, in case of canine osteosarcomas, it has been shown that only non-adherent osteosarcoma stem cells isolated from KTOSA5 and CSKOS cell lines have the ability to form microtumors on the CAM after an incubation period of 5 days, in contrast to adherent KTOSA5 and CSKOS cells. In the presented study, we have proven that the commercial adherent canine osteosarcoma cell line (D-17) can form vascularized tumors on the CAM after the incubation period of 10 days.

Osteosarcoma (OSA) is the most common type of bone tumors in dogs, which has high metastasis ability. 80 % of dogs with OSA die due to lung metastasis. As a result its treatment is a challenge for veterinary practitioners. The authors discuss the etiology, pathogenesis and the possible risk factors of OSA. The article focuses on literature review and the study of recent advances in OSA treatment. The authors describe therapies which have significantly prolonged the lives of dogs, as well as those that have proven to be ineffective. Advantages and disadvantages of limb amputation and limb-sparing surgery have been described. Authors present also the results of both single agent's therapies with the most commonly used drugs as cisplatin, carboplatin and doxorubicin and compare them to the results obtained using combined chemotherapy. The use of nanotechnology as a new approach in OSA treatment in order to avoid multidrug resistance and reduce negative side effects of cytostatic drugs is presented. The main reasons of the therapies failure are also provided in this article.

Forty five lymphomas, 14 of T cell origin, 28 of B cell and 3 with null-cell phenotype, were included in this study. Tumors were classified according to the updated Kiel classification system adapted to canine lymphomas. The percentage of Ki67+ cells and mitotic index (MI) were estimated in each specimen. Most of lymphomas (39 of 45) had high proliferation activity. Among them in 27 cases 50-70% of lymphoma cells expressed Ki67, the highest Ki67 expression (>70% Ki67+cells) was identified less frequently, in 12 cases. Moderate Ki67 expression (20-50% positive cells) was observed in 5 cases, only one tumor had low Ki67 expression (vs. 3.33). Moreover, high positive correlation between the expression of Ki67 and MI was found (r = 0.668; P ≤ 0.001). In T-cell tumors the correlation was very high (r = 0.83; P ≤ 0.001) and in B-cell lymphomas the correlation was high (r = 0.61; P ≤ 0.001). There were also differences between mean MI values in the lymphomas of different morphological subtypes, but in some of them high variations in the range of MI values were identified and wide overlaps of MI between individual cases from different subtypes were observed. Because of differences in the proliferation activity in single cases of the same subtype of lymphoma, the proliferation activity assessment may be helpful to chose appropriate scheme of treatment and should be commonly performed during routine histopathological diagnosis of canine lymphomas.

Lymphoma is one of the most common malignant tumours occurring in dogs. Since there is a constant need for new, more comprehensive laboratory diagnostic tools which permit the precise determination of many tumour-related factors we decided to verify whether the use of microarray analysis could be helpful in classifying lymphomas. The study was performed on samples collected from 7 dogs in which multicentric lymphoma was recognized. Among this group we were able to identify one sub-cluster of transcriptionally similar tumours, which completely differed in terms of the histopathological examination. Among them there were one diffuse large B cell lymphoma, one diffuse macronucleolated medium-sized cell lymphoma and one pleomorphic mixed small and large T-cell lymphoma. The lymphomas belonging to the sub-cluster differed from other analysed tumours in the expression of more than 100 genes of which only 18 were described earlier in regard to lymphomas.

An 11-year-old, 24-kg, intact female Siberian husky dog in anestrus had a 2-month history of polyuria and polydipsia. The dog had signs of mineralocorticoid excess such as hypertension and hypokalemia refractory to potassium supplementation. Abdominal ultrasound revealed an irregular mass in the left adrenal gland. The ACTH stimulation test for aldosterone concentration did not reveal hyperaldosteronism. Unilateral adrenalectomy was performed and histopathology identified adrenal cortical carcinoma. All clinical signs of mineralocorticoid excess ceased after surgery.

Immunohistochemical study of expression of immunoglobulins in canine B-cell lymphomasNineteen canine lymphomas were included in this study. Tumors were classified according to the updated Kiel classification adapted for canine lymphomas by Fournel-Fleury et al. Immunoglobulin light chains (κ and λ) and IgM and IgG expression were determined by immunohistochemical method. In all examined cases neoplastic cells were positive for one of the immunoglobulin light chains. Expression of λ light chains and κ light chains was observed in 18/19 and 1/19 tumors, respectively. In the majority of neoplastic cells in each examined specimen this reaction had a membranous pattern (sκ/sλ). In all examined cases the presence of immunoglobulin light chains was also observed in the cytoplasm of some neoplastic cells (cκ/cλ). These cells were usally rare and never constituted a dominant population. The expression of immunoglobulin was found in 13/19 cases. Most lymphomas were sIgM positive (11/13 cases). In one case expression of IgG was found, and in another lymphoma two populations of neoplastic cells with different expression of examined immunoglobulins (cells with IgM+and IgG+phenotypes) were observed. The reaction also had a membranous pattern. The cells containing cytoplasmic immunoglobulins were rare, and in most cases were of the same type as the surface immunoglobulins. Our study has confirmed that canine lymphomas are a monoclonal proliferation of B-cells usually expressing immunoglobulin λ light chains and that the vast majority of tumors deriving from B-cells express IgM. Our study also indicates a possibility of occurence of biclonal lymphomas in canine species.