Cytotoxic effects of crotoxin from Crotalus durissus terrificus snake in canine mammary tumor cell lines

Background: Mammary gland tumors are the most prevalent neoplasm in intact female dogs, and they are good natural models to study comparative oncology. Most canine mammary malignancies, as in women, are commonly refractory to conventional therapies and demand continuous new therapeutic approaches. Crotalus durissus terrificus, also called rattlesnake, has more than 60 different proteins in its venom with multiple pharmaceutical uses, such as antitumor, antiviral, and antimicrobial action. Crotoxin, a potent β-neurotoxin formed by the junction of two subunits, a basic subunit (CB-PLA2) and an acidic subunit (crotapotin), has already been reported to have anticancer properties in different types of cancers. Methods: In this work, we describe the cytotoxic potential of crotoxin and its subunits compared to doxorubicin (drug of choice) in two canine mammary carcinoma cell lines. Results: Crotoxin, CB-PLA2, crotalic venom, and doxorubicin decreased cell viability and the ability to migrate in a dose-dependent manner, and crotapotin did not present an antitumoral effect. For all compounds, the predominant cell death mechanism was apoptosis. In addition, crotoxin did not show toxicity in normal canine mammary gland cells. Conclusion: Therefore, this work showed that crotoxin and CB-PLA2 had cytotoxic activity, migration inhibition, and pro-apoptotic potential in canine mammary gland carcinoma cell lines, making their possible use in cancer research.

Expression of LIN28A/B and Let-7 miRNAs in canine mammary carcinomas / Expressão de LIN28A/B e Let-7 miRNAs em carcinomas mamários caninos

LIN28 is a RNA-binding protein including two highly conserved homologous, LIN28A and LIN28B. Proto-oncogenes such as LIN28A and LIN28B are generally targeted by the let-7 miRNAs in different types of human cancers. Here, we determined the expression of LIN28A in canine mammary tumor samples and the LIN28/let-7 pathway in canine mammary cell lines. In those cell lines, we identified a functional LIN28/let-7 pathway which exhibited high expression of let-7 members and low expression of its targets, including LIN28A and LIN28B. However, the mammary carcinoma tissue samples showed a frequent expression of LIN28A being expressed mainly in the epithelial cells. No association was observed between LIN28A expression and histopathological classification and grade, TNM and survival time. Our results suggested a possible role of the LIN28A protein in the development of canine mammary carcinomas due to the high frequency observed in the tumor samples (28 of 32). The in vitro experiments suggested that the LIN28/let-7 pathway is active in the tumor cells evaluated. However, more studies are necessary to elucidate the exact role of LIN28/let-7 pathway in canine mammary carcinomas.

LIN28 é uma proteína de ligação ao RNA, com duas formas homólogas altamente conservadas, LIN28A e LIN28B. Os proto-oncogenes LIN28A e LIN28B são regulados pela família de miRNAs let-7 em diferentes tipos de cânceres em humanos. No presente trabalho, o objetivo foi determinar a expressão de LIN28A em amostras de tumor mamário de cadelas e a via LIN28/let-7 em linhagens celulares mamárias caninas. Nestas linhagens, através das técnicas de qPCR e RNAseq, foi identificado que a via LIN28/let-7 apresenta-se funcional, com alta expressão dos membros da família let-7 e baixa expressão de seus alvos, entre eles LIN28A e LIN28B. No entanto, as amostras de tecidos de carcinomas mamários caninos demonstraram expressão frequente de LIN28A, sendo observada principalmente em células epiteliais. Não foram observadas associações entre expressão de LIN28A com classificação e gradação histopatológicas, TNM e tempo de sobrevida. Nossos resultados sugerem uma possível relação da proteína LIN28A no desenvolvimento de carcinomas mamários caninos devido à alta frequência observada nas amostras tumorais (28 de 32). Os experimentos in vitro sugerem que a via LIN28/let-7 é ativa nas linhagens celulares caninas avaliadas. Entretanto, estudos funcionais ainda são necessários para elucidar a função exata da via LIN28/let-7 nos carcinomas mamários caninos.

Evaluation of the immunomodulatory activity of thalidomide on tumor-associated macrophages in the 4T1 murine metastatic breast cancer model / [Avaliação do efeito imunomodulador da talidomida em macrófagos associados a tumores no modelo murino de câncer de mama metastático 4T1]

The present work evaluated the immunomodulatory effect of thalidomide (Thal) at different doses on tumor-associated macrophages (TAMs) using a mouse model of human breast cancer. Mice were inoculated with 4T1 cells in the left flank and treated with Thal once a day at concentrations of 50, 100, and 150mg/kg body weight from the 5th day until the 28th day of tumor inoculation. The tumors were sized, proliferation index and TAMs count were evaluated in primary tumors and metastatic lungs. In addition, the metastasis rate was evaluated in the lungs. Thal at 150mg/kg significantly decreased tumor growth, proliferation index, and TAMs infiltration in primary tumors. Conversely, a higher number of TAMs and lower proliferation index were observed in metastatic lungs in mice treated with 150mg/kg of Thal. Furthermore, Thal at 150mg/kg significantly decreased the metastatic nodules in the lungs. Our findings demonstrated that Thal treatment considerably decreased the primary tumor and lung metastasis in mice associated with different TAM infiltration effects in these sites.(AU)

No presente trabalho, foi avaliado o efeito imunomodulador de diferentes doses de talidomida em macrófagos associados ao tumor (TAMs), em um modelo murino de câncer de mama. Camundongos foram inoculados com células 4T1, na região do flanco esquerdo, e tratados com talidomida, uma vez ao dia, nas doses de 50, 100 e 150mg/k, por massa corporal, do quinto dia ao 28º dia de inoculação tumoral. Os tumores foram medidos, o índice de proliferação celular e a contagem de TAMs foram avaliados nos tumores primários e nos pulmões com metástases. Além disso, a taxa de metástases pulmonares também foi avaliada. A talidomida na dose de 150mg/kg diminuiu significativamente o crescimento tumoral, o índice de proliferação celular e a infiltração de TAMs nos tumores primários. Por outro lado, maior número de TAMs e menor índice de proliferação celular foram observados nos pulmões metastáticos, em camundongos tratados com 150mg/kg de talidomida. Ademais, a talidomida na dose de 150mg/kg diminuiu significativamente os nódulos metastáticos nos pulmões. Os resultados demonstraram que o tratamento com talidomida diminuiu o crescimento tumoral e as metástases pulmonares em camundongos, associado com diferentes efeitos na infiltração de TAMs nesses locais.(AU)

Histopathological and immunohistochemical characteristics of malignant adenomyoepithelioma in a cat: case report / [Características histopatológicas e imuno-histoquímicas do adenomioepitelioma maligno em gata: relato de caso]

The malignant adenomyoepithelioma is a rare mammary tumor in women and uncommon in cats with only one report in this species. In this case report, the histopathological and immunohistochemical characteristics of six cases of malignant adenomyopithelioma in the feline mammary gland are described. Microscopic evaluation of tumors showed dense cellular neoplastic proliferation, composed of malignant myoepithelial and epithelial cells, formed by varied arrangements and presenting papillary, tubular and solid nest proliferation. Immunohistochemistry was performed for markers Ki67, Cox-2, RE, RP, p63 and HER-2. All cases were positive for p63, confirming the myoepithelial nature of neoplastic cells. The diagnosis of malignant adenomyopithelioma was made possible through the association between histopathological characteristics and immunohistochemical results.(AU)

O adenomioepitelioma maligno é uma neoplasia mamária rara em mulheres e incomum em gatas, possuindo apenas uma descrição nessa espécie. Neste relato de caso, são descritas as características histopatológicas e imuno-histoquímicas de seis casos de adenomioepitelioma maligno na glândula mamária felina. A avaliação microscópica dos tumores demonstrou proliferação neoplásica densamente celular, composta por células mioepiteliais e epiteliais malignas dispostas em padrão papilar, tubular e ninhos sólidos. Foi realizada técnica de imuno-histoquímica para os marcadores Ki67, Cox-2, RE, RP, p63 e HER-2. Todos os casos foram positivos para p63, confirmando a natureza mioepitelial das células neoplásicas. O diagnóstico de adenomioepitelioma maligno foi possível por meio da associação entre as características histopatológicas e os resultados de imuno-histoquímica.(AU)

Presença da mutação do gene BRCA1 em cadelas com tumores mamários malignos / Presence of BRCA1 gene mutation in bitches with malignant mammary tumors

Mammary tumors (MTs) in bitches are similar to breast cancers in women. Thus, they can be used as a model for human breast cancer and findings can be extrapolated for use in human medicine. BRCA1 is a tumor suppressor gene. When the gene has a mutation, it cannot repair damaged DNA, which causes genetic instability and tumorigenesis. Therefore, we aimed to study the frequency of single nucleotide polymorphisms (SNPs) in the BRCA1 gene that are associated with distinct histological types of malignant MT in bitches. The study population consisted of 91 bitches, including a control group of 6 animals with healthy mammary glands and 85 animals with MTs. All animals underwent a presurgery evaluation consisting of a questionnaire administered to the person responsible for the animal, a physical examination, collection of peripheral blood for hematological and serum biochemistry evaluations, an electrocardiogram, and a preanesthesia evaluation. In addition, distant metastasis was studied via chest radiography and abdominal ultrasound. After evaluations were complete, the animals that could undergo surgery were administered general anesthesia and underwent a mastectomy or mammary gland sample collection. Histopathological examination and molecular analysis were performed to identify mutations in the BRCA1 gene. Histopathological examinations found 10 different types of malignant tumors in 36 sick animals. Tumor samples plus samples from the 6 control animals were subjected to DNA extraction, polymerase chain reaction (PCR) analysis, and genetic sequencing. The tumor with the highest incidence (33.33%) was a complex carcinoma, followed by carcinoma in mixed tumor (13.88), tubular carcinoma (13.88) and carcinosarcoma (13.88). Molecular analysis revealed 3 different SNP points in 5 samples (4006G>A, 3619A>G, and 3761C>T). The allelic variant 4006G>A (1/36) resulted in the alteration of the amino acid valine by isoleucine (V1336 I). The mutation 3619A>G (2/36) inserted the amino acid alanine instead of threonine (T1207 A). The mutation 3761C>T (2/36) led to the alteration of the amino acid serine by phenylalanine (S1254 F), a mutation for which there are no published reports. The histological types that showed BRCA1 mutations were complex carcinoma (1/5), carcinoma in mixed tumor (1/5), papillary carcinoma (1/5) and tubular carcinoma (2/5). Software analysis identified the new SNP (nucleotide 3761) in BRCA1 and 2 point mutations in nucleotides 4006 and 3619 and responsible for genetic instability. The development of breast cancer is caused by many endogenous and exogenous factors. The results of our study show that these factors have a greater presence in female, mixed breed, uncastrated, and older dogs, confirming the data in the veterinary literature. In the present study, we found different histological types of malignant breast tumors with mutations in the BRCA1 gene, as other authors have reported. However, we also found the mutation 3761C>T, which, to the best of our knowledge, has not been reported in the literature. This shows the need for studies in veterinary medicine that assess mutations in the BRCA1 gene and the most common histological types. In conclusion, SNPs in the BRCA1 gene cause genetic instability, resulting in additional mutations that lead to the development of breast tumors. They are point mutations that affect transcription, resulting in truncated proteins. These proteins may have a loss of function, leading to carcinogenesis.(AU)

Eletrocardiografia computadorizada em cadelas com tumores mamários / Electrocardiography in bitches with mammary tumors

The incidence of cancer has increased due to greater longevity of the animals as a consequence of better control of other diseases, improvement of nutrition and good practices in preventive medicine. Malignant tumors can cause paraneoplastic syndrome such as hypercalcemia, anemia, cachexia, among others and consequent cardiovascular disorders. The electrocardiography (ECG) is a complementary exam that can reveal with its traces these rhythmic disorders. Based on that, the objective of this study was to evaluate the ECG in bitches with mammary tumors in order to detect in which type of tumor would be found significant changes as in cardiac rhythm, ECG waves, segments or cardiac axis. Twenty-nine female dogs were used in this study, being 19 bitches with mammary tumor, and they were allocated in three groups: G1: control group (n = 10), G2: benign neoplasia group (n = 6) and G3: malignant neoplasia group (n = 13). The most prevalent type of neoplasia in G2 was the benign mixed tumor (83%), followed by adenoma (17%) whereas in G3: carcinoma in mixed tumor (61%); papillary carcinoma (23%). Regarding cardiac rhythm, it was found sinus arrhythmia (SA) and normal sinus rhythm (NS): G1: 50% SA and 50% NS; G2: 67% SA and 33% NS; G3: 54% SA and 46% NS. No ventricular or atrial arrhythmias were detected. For other parameters in G1, G2 and G3, respectively (mean ± Std error): FC (bpm): 110±9.2, 120 ± 8.5, 124±7,5; P (ms): 48 ± 1.6, 51 ± 1.8, 50 ± 1.2; P (mV) 0.19 ± 0.02, 0.2 ± 0.02, 0.19 ± 0.02; PR (ms): 94 ± 4.3, 93 ± 5.5, 89 ± 3.9; QRS (ms): 56 ± 1.54, 60 ± 4, 62 ± 1.2; R (mV): 1.1 ± 0.06, 1.2 ± 0.24, 0.9 ± 0.13; QT (ms): 203 ± 9.4; 204 ± 7.9; 182 ± 15.6; and cardiac axis (°): 66 ± 6.2, 61 ± 7.9, 70 ± 7.5. There were no significant differences for all cardiac parameters and also for ST interval and T wave morphology. All electrocardiographic parameters found are in accordance with other studies carried out in the canine species. The results regarding tumor types differ from what was found in another study, in which in 18 bitches with mammary tumors, 55% were benign, with prevalence of adenomas (38%) followed by benign mixed tumors, and 45% malignant, with adenocarcinoma prevailing (22%). In another study, it was verified in 63 bitches the predominance of tubular carcinoma (26.56%) and carcinoma in mixed tumors (23.44%). Diverging from the electrocardiographic parameters of this study, a significant difference was found in the R wave amplitude value in the research by Barros et al., (2015) who performed computerized electrocardiography in 50 dogs, not only with mammary neoplasms (55% mammary carcinomas), but also in mastocytomas, lymphomas, benign tumors and other sarcomas. This author found out that the R wave amplitude values of the neoplasia group were lower when compared to the control group. In addition, we suspect that other types of tumors could result in more paraneoplastic syndrome than the mammary neoplasms found in this research. Neoplasms as lymphomas (T cells), apocrine gland anal sac adenocarcinomas, multiple myelomas and thymomas are known as a cause of hypercalcemia of malignancy and histiocytic sarcomas, myelomas, leukemia and lymphomas causing anemia. In conclusion, ECG has no changes in benign or malignant mammary tumors in dogs. However, this fact does not exclude the importance of its performance in pre-anesthetic evaluations. Further studies with a larger sample including the clinical staging of these bitches with a balanced number of animals with low and high staging are suggested.(AU)

Evaluation of platelet indices and complete blood count in canine mammary tumors

Malignant mammary tumors in humans and bitches cause hematological disorders such as anemia, erythrocytosis, thrombocytosis, hyperproteinemia, and leucopenia. Novel studies have been conducted on the predictive and prognostic values of platelet (PLT) indices in human breast cancer (HBC). However, there is little information about the alterations in hematological parameters in canine mammary tumors (CMTs). The aims of this study were to evaluate the platelet indices and complete blood count (CBC) parameters in bitches with and without mammary tumor and to assess the above mentioned parameters with regard to histological tumor types and grades. A total of 71 bitches were enrolled in this study. The bitches in the study group were divided into 2 groups which consisted of malignant epithelial mammary tumors (group EMT; n = 43) and malignant mixed mammary tumors (group MMT; n = 12). Control group (group C) consisted of clinically and gynaecologically healthy 16 bitches. Blood samples were obtained to perform the CBC and PLT indices analysis. Histopathological examinations were carried out under a light microscope. Histological tumor types and malignancy grades were classified. The bitches with mammary tumor showed significantly increased PLT values and decreased hematocrit (HCT), hemoglobin (HGB) and mean corpuscular hemoglobin (MCH) values versus the healthy ones, regardless of the tumor type. However, in comparisons with the group C, mean platelet volume (MPV) and mean corpuscular hemoglobin concentration (MCHC) values were different only in the group MMT, while plateletcrit (PCT) and mean corpuscular volume (MCV) values were different only in the group EMT. Also white blood cell (WBC), PLT and PCT values were higher than the referenced laboratory ranges in grade 3 tumors. In the presented study, MPV was considerably correlated with PLT, platelet distribution width (PDW) and PCT. Also, PCT and PLT had high sensitivity and specificity to distinct EMT and MMT from the healthy bitches. Microcytic and hypochromic anemia occurs due to the decrease in the amount of HGB. Levels of MCV, MCH, and MCHC in the HBC group were reported to be significantly lower than in humans without breast cancer. Although anemia did not occur in EMT and MMT groups, obtained significances in the HCT, HGB, MCV, MCH, and MCHC levels between the bitches with and without mammary tumor were in line with the previous reports. In this study, WBC levels in grade 3 tumors were significantly higher than grade1 tumors (P < 0.05). Whereas levels of WBC in grade 1 and grade 2 tumors were in referenced laboratory ranges, it was higher in grade 3. Increased level of WBC in grade 3 was supposed to be due to the rise in malignancy as previously reported. Thrombocytosis was detected in 48.83% and 41.66% of the bitches in EMT and MMT groups, respectively. The higher percentage of CMTs with thrombocytosis in this study might be due to the difference in referenced upper limit of PLT in previous studies. The elapsed time between tumor formation and clinical presentation could be another influencing factor. Although PLT and PCT values were not significant according to the histological grading in this study, both parameters were found to be higher in grade 3 than the normal reference values. Further studies conducted with higher populations may lead the differences in these parameters to significance. With the support of further studies, alterations in the above mentioned parameters in bitches may contribute in the diagnosis process, management of treatment and may constitute an easy way to have an idea about the prognosis of mammary tumors.(AU)

Oxidative stress in female dogs with mammary neoplasms / Estresse oxidativo em cadelas com neoplasia mamária

The result of the reaction of free radicals with biomolecules is the formation of substances with the potential of inducing oxidative damage, a condition known as oxidative stress. There are voluminous literature data reporting the association, both as a cause and as a consequence, between different diseases and oxidative stress. In this study, 144 female dogs with mammary neoplasia were analyzed. The animals were submitted to clinical evaluation for disease staging, hematological evaluation, serum biochemistry (renal and hepatic function tests), and dosage of the oxidative damage biomarker, malondialdehyde (MDA), at the time of its approach and 30 days after treatment. A control group of 100 healthy animals was also submitted to determination of serum MDA levels. The mean age of the animals affected by mammary neoplasms was 9.88±2.95 (4 to 14) years, while in healthy animals it was 2.31±1.90 years (1 to 6). Of the 144 animals, 113 (78.9%) had malignant neoplasms, and 15, 21, 46, 17 and 14 animals were in clinical stage I, II, III, IV and V respectively and the carcinoma in a mixed tumor was the most frequent histological pattern in this group (26%). Thirty-one animals were diagnosed with benign neoplasms and mammary adenoma was the most frequent histological pattern in 15 animals (51.61%). Hematological changes in the preoperative period were observed in 44 (38.9%) and 12 (38.7%) animals with malignant and benign neoplasias, respectively, and there was a positive correlation between anemia and higher levels of MDA (P=0.0008) for animals with malignant tumors. Regarding serum biochemical parameters, the most frequent alterations in animals with malignant neoplasms were elevated ALT levels in 12 animals (10.6%), creatinine in 10 animals (8.84%) and urea in eight animals (7.07%). Females with benign neoplasms presented less occurrence of changes in these parameters. In the group of healthy animals (control), the mean serum MDA values were 12.08±4.18, whereas in the pre-treatment group, mean MDA was 24.80±5.74 for bitches with benign neoplasms and 32.27±10.24 for bitches with malignant tumors. A significant increase (P<0.001) in MDA levels was observed in animals with malignant mammary neoplasms when compared to healthy animals and with benign tumors. In addition, a significant reduction (P<0.001) was observed 30 days after treatment in MDA levels (27.37±7.86) in animals with malignant tumors. In conclusion, our results indicate an association between MDA seric levels and mammary neoplasms in dogs. The results suggest that this factor can be used as a biomarker of oxidative stress with a potential impact in the prognostic of mammary tumors, since significantly higher levels of MDA were detected especially in dogs carrying malignant tumors and presenting anemia.(AU)

O resultado da reação de radicais livres com biomoléculas é a formação de substâncias que podem ser utilizadas como marcadores de dano oxidativo, condição mais conhecida como estresse oxidativo. Evidências científicas comprovam a relação, quer como causa, quer como consequência, entre muitas doenças e o estresse oxidativo. Neste estudo, 144 cadelas portadoras de neoplasia de mama, foram submetidas à avaliação clínica para estadiamento da doença, avaliação hematológica, testes de função renal e hepática e dosagem do biomarcador de dano oxidativo, malondialdeído (MDA), no momento de sua abordagem e 30 dias após realização de tratamento. Um grupo controle de 100 cadelas saudáveis foi submetido também à determinação dos níveis séricos de MDA. A idade média dos animais acometidos por neoplasias mamárias foi de 9,88±2,95 (4 a 14) anos, enquanto que nos animais saudáveis foi de 2,31±1,90 anos (1 a 6). Dos 144 animais, 113 (78, 9%) apresentavam neoplasias malignas, sendo que 15, 21, 46, 17 e 14 animais encontravam-se em estadiamento clínico I, II, III, IV e V respectivamente, e o carcinoma em tumor misto foi o padrão histológico mais frequente neste grupo (26%). Trinta e um animais tiveram diagnóstico de neoplasias benignas, sendo que 7 estavam no estádio I, 16 no estádio II e 8 no estádio III e o adenoma mamário foi o padrão histológico mais frequente em 15 animais (51,61%). Alterações hematológicas no período pré-operatório foram observadas em 44 (38,9%) e 12 (38,7%) animais portadores de neoplasias malignas e benignas, respectivamente, sendo que houve correlação positiva entre anemia e níveis mais elevados de MDA (P=0,0008), para os animais com tumores malignos. Em relação aos parâmetros bioquímicos séricos, as alterações mais frequentes nos animais com neoplasias malignas foram a elevação dos níveis de ALT em 12 animais (10,6%), de creatinina em 10 animais (8,84%) e de ureia em oito animais (7,07%) Cadelas portadoras de neoplasias benignas apresentaram menor ocorrência de alterações nesses parâmetros. No grupo controle, a média dos valores séricos de MDA foi 12,08±4,18, enquanto que no grupo pré-tratamento, a média de MDA foi de 24,80±5,74 para as cadelas com neoplasia benigna e 32,27±10,24 para as neoplasias malignas. Verificou-se aumento significativo do valor sérico de MDA em cadelas portadoras de neoplasias malignas em comparação com os animais hígidos ou com neoplasias benignas (P<0,001). Ainda, 30 dias após o tratamento observou-se uma diminuição significativa (P<0,001) no valor médio de MDA (27,37±7,86) nos animais com neoplasias malignas. Em conclusão, os resultados deste estudo evidenciam uma associação entre níveis séricos aumentados de MDA e presença de neoplasias mamárias em cadelas. Os resultados sugerem que este fator pode ser utilizado como biomarcador de estresse oxidativo em cães, com provável impacto no prognóstico dos tumores mamários, uma vez que níveis significativamente mais altos de MDA foram detectados especialmente nas cadelas portadoras de tumores malignos e apresentando anemia.(AU)

Doenças de felinos domésticos diagnosticadas no sul do Rio Grande do Sul: estudo de 40 anos / Domestic feline diseases diagnosed in southern Rio Grande do Sul: a 40-year study

O objetivo deste estudo foi identificar as principais doenças de felinos na região sul do Rio Grande do Sul. Foram revisados os protocolos de necropsia e das amostras biológicas de felinos encaminhados ao Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (LRD/UFPel), no período de 1978 a 2018. Nesse período foram recebidas 1633 amostras de felinos, sendo 363 (22%) entre os anos de 1978 e 1999 e 1270 (78%) entre os anos de 2000 e 2018. Com relação aos diagnósticos, 457 felinos (28%) apresentaram tumores benignos ou malignos, sendo os tegumentares e os mamários os mais frequentes. As doenças bacterianas, fúngicas, virais, parasitárias, sem agente definido e as intoxicações totalizaram 554 casos (33,9%), destacando-se a esporotricose, com 12,8% dos diagnósticos. Concluiu-se que, na região sul do RS, o encaminhamento de felinos para diagnóstico aumentou significativamente após o ano 2000, comprovando que a espécie passou a ter maior importância como animal de companhia. Concluiu-se, também, que as neoplasias têm papel relevante entre as doenças de felinos e que a esporotricose é uma das mais importantes zoonoses na região.(AU)

The goal of this paper was to identify the main disease affecting felines in the southern region of Rio Grande do Sul. The necropsy protocols and feline biological materials submitted to the Regional Diagnostic Laboratory of the Veterinary College of the Federal University of Pelotas (LRD / UFPel) were reviewed, from 1978 to 2018. During this period 1633 feline samples were received, 363 (22%) between 1978 and 1999 and 1270 (78%) between 2000 and 2018. 59% of felines did not present a defined breed. As for diagnoses, 457 felines (28%) presented benign or malignant tumors, the most common being the integumentary and mammary tumors. Bacterial, fungal, viral, parasitic or undefined agent infections and intoxications were observed in 554 cases (33.9%), especially sporotrichosis with 12.8 % of the diagnoses. It was concluded that in southern RS the referral of cats for diagnosis increased significantly after the year 2000, proving that they became more significant as companion animals. It was also concluded that neoplasia play a relevant role among feline diseases, and that sporotrichosis is one of the most important zoonoses in the region.(AU)

Risk factors associated with mammary tumors in female dogs / Fatores de risco para tumores mamários em cadelas de Uberlândia e Patos de Minas, Minas Gerais

Mammary tumors in female dogs are the most frequent and corresponds to half of the canine tumors. The objectives of this study were to determine the risk factors associated with the occurrence of mammary tumors in female dogs and to evaluate the macroscopic characteristics of these neoformations, using 386 dogs from the "Outubro Rosa Pets" events done within the cities of Uberlândia and Patos de Minas, Minas Gerais State, Brazil, in 2015 (n=194), 2016 (n=105) and 2017 (n=87). For the determination of risk factors, the binary logistic regression test (P<0.05) was performed. The occurrence of mammary tumors was 23.6% (91/386). The significant risk factors identified were increased age (P<0.001), overweight (P=0.048) and non-castration (P<0.001) with a chance of, respectively, 1.6, 2.3 and 9.3 times for the development of mammary tumors. In dogs with mammary tumors (n=91), 153 lesions were present, of which 39 female dogs had two or more lesions (42.8%). Most of the lesions were at the caudal abdominal (M4) and inguinal (M5) mammary glands (60.13%, 92/153). Relative to the size of the lesions, it was observed that in 78% of the female dogs the lesions were determined asT1 (<3cm), 16.5% were T2 (3-5cm) and 5.5% T3 (>5cm). At least 15.4% (14/91) of the dogs had one of the regional lymph nodes increased. In conclusion, the occurrence of mammary tumors in the evaluated population was 23.6% and that age, overweight and non-realization of ovariohysterectomy are risk factors associated with the development of mammary tumors.(AU)

Em cadelas os tumores mamários são os mais frequentes e correspondem a aproximadamente metade dos tumores em cães. Este estudo teve os objetivos de determinar os fatores de risco envolvidos na ocorrência de tumores mamários em cadelas e avaliar as características macroscópicas destas neoformações, utilizando 386 cadelas do evento "Outubro Rosa Pets" nos municípios de Uberlândia e Patos de Minas, Minas Gerais, Brasil, em 2015 (n=194), 2016 (n=105) e 2017 (n=87). Para a determinação dos fatores de risco utilizou-se o teste de Regressão logística binária (P<0,05). A ocorrência de tumores mamários foi de 23,6% (91/386). Os fatores de risco significativos identificados foram aumento da idade (P<0,001), sobrepeso (P=0,048) e não-castração (P<0,001) com a chance de, respectivamente, 1,6, 2,3 e 9,3 vezes de desenvolvimento de tumores mamários. Nas cadelas com tumores mamários (n=91), constatou-se a presença de 153 lesões, sendo que 39 cadelas apresentaram duas ou mais lesões (42,8%). A maioria das lesões localizaram-se nas mamas abdominais caudais (M4) e inguinais (M5) (60,13%; 92/153). Em relação ao tamanho das lesões, observou-se que 78% das cadelas eram T1 (<3cm), 16,5% T2 (3-5cm) e 5,5% T3 (>5cm). Pelo menos 15,4% (14/91) das cadelas apresentaram um dos linfonodos regionais aumentados. Conclui-se que a ocorrência dos tumores mamários na população avaliada foi de 23,6% e que a idade, sobrepeso e não ovariohisterectomia são fatores de risco para o desenvolvimento de tumores mamários.(AU)

Osteopontin expression and its relationship with prognostic biomarkers in canine mammary carcinomas / Expressão de osteopontina e sua relação com biomarcadores prognóstico nos carcinomas mamários caninos

Osteopontin is a glycophosphoprotein implicated in different physiologic and pathologic processes and is known to be involved in progression and metastasis of various cancers in humans, but this relation is still little explored in the veterinary. The aim was to evaluate the expression of osteopontin in canine mammary carcinomas and its relation with well-established canine mammary tumor biomarkers. For that, expression of OPN, EGFR, HER2, and c-Kit were evaluated along with Ki67 rate in 43 mammary carcinomas. Osteopontin was demonstrated to be expressed by neoplastic epithelial cells in all carcinomas as well as in stromal cells from the tumor microenvironment. Relation between high osteopontin expression and EGFR positivity (P<0.001) and HER2 overexpression (P=0.012) was demonstrated. In conclusion, high OPN expression seems to be related to poor prognosis and MAPK pathway activation, given the association with EGFR and HER2, members of the MAPK signaling pathway.(AU)

A osteopontina é uma glicofosfoproteina implicada em diferentes processos fisiológicos e patológicos, sendo conhecida por estar envolvida na progressão e metástase de vários cânceres nos humanos, no entanto, essa relação é ainda pouco explorada na veterinária. O objetivo deste trabalho foi avaliar a expressão da osteopontina nos carcinomas mamários caninos e sua relação com biomarcadores bem estabelecidos para esta neoplasia. Para isto, foi avaliada a expressão de OPN, EGRH, HER2 e c-Kit juntamente com a taxa de Ki67 em 43 carcinomas mamários. A osteopontina foi expressa pelas células epiteliais neoplásicas em todos os carcinomas, assim como, nas células estromais do microambiente tumoral. Foi demonstrada uma relação entre uma alta expressão de osteopontina e positividade para EGFR (P<0.001) e superexpressão de HER2 (P=0.012). Em conclusão, alta expressão de OPN parece estar relacionada com mau prognóstico e ativação da via MAPK, devido a sua associação com EGRF e HER2, os quais são membros desta via de sinalização.(AU)

Dosagem sérica do marcador tumoral CA 15. 3 em cadelas portadoras de neoplasias mamárias pelo método de eletroquimioluminescência / Serum dosage of the tumor marker Ca 15. 3 in bitches presenting mammary neoplasia with the chemiluminescence method

The objective of the present study was to analyze the serum levels of the tumor marker Ca15.3 in healthy bitches and those with mammary neoplasms, correlating results with tumor type, clinical staging, time until presentation, and presence of ulceration and vascularization. For the study, 30 bitches with mammary tumors and 30 healthy bitches (control group) were selected. Histopathology was performed for identification of tumor type, and blood was collected for measurement of serum concentration of the marker via the chemiluminescence method using a commercial kit. A higher frequency of malignant neoplasms was observed (76.7%), with a higher quantity of carcinoma in mixed tumor (26.7%). Regarding serum concentration of the marker Ca15.3, there was no difference in serum values when comparing the means from bitches with neoplasia and healthy bitches, nor when comparing the other characteristics. The majority of results for serum concentration of Ca15.3, whether in bitches with neoplasia or in healthy bitches, was zero. It is concluded that the measurement of the marker Ca15.3 using the chemiluminescence method and commercial kits for humans did not offer significant results that would make this method or this marker a useful tool for patient monitoring and evaluation of the prognosis of bitches with mammary neoplasms.(AU)

First description of basaloid carcinoma of the canine mammary gland: case report / Primeira descrição do carcinoma basaloide da glândula mamária canina: relato de caso

The objective of this case report was to describe histopathological and immunohistochemical characteristics of the first reported basaloid carcinomas in the canine mammary gland. Two bitches were treated for tumors in the mammary gland and underwent mastectomy. Microscopic evaluation of these tumors revealed epithelial cells arranged in a predominantly solid pattern with hyperchromatic peripheral cells arranged in a palisade pattern. Metastases in regional lymph nodes were found in both animals, and one bitch exhibited pulmonary metastasis. Immunohistochemistry revealed positive labeling for the basal cell markers cytokeratin 14 and p63. Histopathological and immunohistochemical findings led to diagnoses of basaloid carcinoma of the canine mammary gland with regional and distant metastasis.(AU)

O objetivo deste relato de caso é descrever as características histopatológicas e imuno-histoquímicas do primeiro relato de carcinoma basaloide na glândula mamária canina. Duas cadelas foram atendidas com tumores na glândula mamária e foram submetidas à mastectomia. A avaliação microscópica demonstrou células epiteliais arranjadas em um padrão predominantemente sólido, com células periféricas hipercromáticas, dispostas em paliçada. As duas apresentaram metástase em linfonodos regionais e uma delas metástase pulmonar. A imuno-histoquímica revelou marcação positiva para citoqueratina 14 e p63, marcadores de células basais. Achados histopatológicos e imuno-histoquímicos levaram ao diagnóstico de carcinoma basaloide da glândula mamária canina com metástase regional e a distância.(AU)

Serum evaluation of leptin, IL-6, IGF-1 and estrogen in obese bitches with early stages of mammary carcinoma / Avaliação sérica de leptina, IL-6, IGF-1 e estrógeno em cadelas com excesso de peso e portadoras de carcinomas mamários em estágio inicial

The aim of this study was to relate the serum concentration IL-6, IGF-1, leptin and estrogen in non-castrated bitches with or without overweight and early stage mammary carcinomas. Forty-three bitches were divided into four groups, two groups without mammary carcinomas with and without overweight, and two groups with mammary carcinomas with and without overweight. Overweight bitches, with or without mammary carcinomas, were statistically different from bitches by ideal weight, in relation to ECC, IMCC and body fat percentages (P< 0.0001). There was a positive correlation between ECC and IMCC (P< 0.0001), ECC and % GC (P< 0.0001), and IMCC and % GC (P< 0.0001). A positive correlation was found between serum leptin and IL-6 (P= 0.0451) and leptin and IGF-1 (P= 0.05). A positive correlation (P= 0.0053) between ECC and leptin was found in the analysis of body evaluation methods and serum concentrations, and a negative correlation between ECC and IL-6 (P= 0.0435). Among the fat percentage and the leptin concentration, there was a positive correlation (P= 0.0016), as found between the IMCC and leptin (P= 0, 0209). In this study, no association was observed between excessive weight and the presence of early stage mammary carcinomas.(AU)

Este estudo teve por objetivo relacionar a concentração sérica de IL-6, IGF-1, leptina e estrógeno, em cadelas não castradas com ou sem excesso de peso, e carcinomas mamários em estágio inicial. Quarenta e três cadelas foram divididas em quatro grupos, sendo dois de cadelas sem carcinomas mamários, com e sem excesso de peso, e dois de cadelas com carcinomas mamários, com e sem excesso de peso. Cadelas com excesso de peso, com ou sem carcinomas mamários, foram estatisticamente diferentes de cadelas em peso ideal, em relação às avaliações corporais de ECC, IMCC e percentual de gordura corpórea (P<0,0001). Foi observada uma correlação positiva entre ECC e IMCC (P<0,0001), ECC e %GC (P<0,0001), e IMCC e %GC (P<0,0001). As análises de estrógeno, leptina, IL-6 e IGF-1 não apresentaram diferenças estatísticas entre os grupos. Demonstrou-se correlação positiva entre as concentrações séricas de leptina e IL-6 (P=0,0451) e leptina e IGF-1 (P=0,05). Encontrou-se correlação positiva entre ECC e leptina (P=0,0053) e negativa entre ECC e IL-6 (P=0,0435). Entre o percentual de gordura e leptina encontrou-se correlação positiva (P=0,0016), assim como entre IMCC e leptina (P=0,0209). Neste estudo, não se observou associação entre excesso de peso e a presença de carcinomas mamários em estadio inicial.(AU)

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

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

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

Evaluation of serum concentrations of cortisol and thyroxine in bitches with early-stage mammary carcinoma / Concentrações séricas de cortisol e tiroxina em cadelas com carcinoma mamário em estádio inicial

In view of the fact that cancer is considered a chronic disease that can interfere with hormonal homeostasis by means of cytokines, we hypothesized that, even at early stages, mammary carcinoma is able to alter the balance of the hypothalamic-pituitary-thyroid and hypothalamic-pituitary-adrenal axes. To test this hypothesis, the serum concentrations of basal cortisol, thyroxine (T4), free thyroxine (fT4), and thyroid-stimulating hormone (TSH) were evaluated in 20 unspayed bitches that had a histopathological diagnosis of grade 1 mammary carcinoma at clinical stage I according to the World Health Organization (WHO) classification (T1N0M0). The control animals comprised 10 unspayed bitches in perfect health conditions that were matched with those with mammary carcinoma by age. No significant differences regarding the concentrations of basal cortisol, TSH, t4, and fT4 were found between the bitches carrying early stage mammary carcinoma when compared to the control group. This suggests that, even if malignant, early-stage mammary carcinomas do not exhibit the ability to alter the concentrations of hormones produced by the hypothalamic-pituitary-adrenal or hypothalamic-pituitary-thyroid axes.(AU)

Em vista do fato de neoplasias serem consideradas doenças crônicas que por meio de citocinas podem interferir na homeostase hormonal, hipotetizou-se que o carcinoma mamário, mesmo nos seus estádios iniciais, fosse capaz de alterar o equilíbrio dos eixos hipotalâmico-hipofisário-tireóideo e hipotalâmico-hipofisário-adrenal. Para tal, foram avaliadas as concentrações séricas de cortisol basal, tiroxina (T4), tiroxina livre (fT4) e tireotrofina (TSH) de 20 fêmeas caninas, inteiras, com diagnóstico histopatológico de carcinoma mamário grau 1 e estadiamento clínico I segundo a classificação da Organização Mundial da Saúde - OMS (T1N0M0). Os animais controle constituíram-se por 10 fêmeas caninas inteiras, em perfeitas condições de higidez, as quais foram pareadas, por idade, com aquelas portadoras de carcinoma mamário. Não foram encontradas diferenças significativas nas concentrações de cortisol basal, TSH, T4 e fT4 das cadelas portadoras de carcinoma mamário em estádio inicial quando comparadas às controles sugerindo que, mesmo considerados malignos, ainda não apresentam a capacidade de alterar as concentrações dos hormônios produzidos pelos eixos hipotalâmico-hipofisário-adrenal e tireóideo.(AU)

Consensus for the diagnosis, prognosis and treatment of feline mammary tumors / Consenso para o diagnóstico, prognóstico e tratamento de tumores mamários em felinos

Mammary neoplasms are described as the third most common type of feline tumor, after haematopoietic and skin tumors, and present a challenge for clinicians because the prognosis for feline mammary tumors ranges from guarded to poor. Thus, it is necessary to define new therapeutic approaches and establish more in-depth knowledge about this disease in felines. The main aspects of the diagnosis, prognosis and treatment of feline mammary neoplasia were discussed, aiming to standardize the criteria and to serve as a guide for pathologists and veterinary clinicians.(AU)

As neoplasias mamárias são descritas como o terceiro tipo mais frequente de tumor em felinos (após as neoplasias hematopoiéticas e cutâneas) e apresentam um desafio para os clínicos devido ao prognóstico, que varia de reservado a ruim. Assim, é necessário conhecer melhor essa doença em felinos e definir novas abordagens terapêuticas. Discutiu-se os principais aspectos de diagnóstico, prognóstico e tratamento da neoplasia mamária felina, com o objetivo de padronizar os critérios e servir de guia para patologistas e clínicos veterinários.(AU)

Linfonodo axilar como sentinela de neoplasia mamária em cadelas / Axillary lymph node as sentinel for mammary neoplasia in bitches

Linfonodo axilar como sentinela de neoplasia mamária em cadelas. O estudo dos tumores de mama em cadelas é de grande importância devido à alta frequência com que surgem na clínica de pequenos animais. O presente estudo teve como objetivo avaliar a importância do linfonodo axilar como sentinela em neoplasias mamárias de cadelas. Foram avaliadas 49 fêmeas com neoplasia mamária, submetidas à mastectomia unilateral total, utilizando o corante azul patente para a identificação do linfonodo axilar, o qual foi submetido à análise histopatológica com a coloração de hematoxilina-eosina e imuno-histoquímica (IHQ) com anticorpo citoqueratina (AE1/AE3) para procura de metástase. Oito cadelas apresentaram metástases em linfonodo axilar, sendo sete detectadas por histopatologia e por IHQ e uma somente pela IHQ (micrometástase). Uma paciente que apresentava tumor em mamas abdominal caudal e inguinal tinha metástase no linfonodo axilar e inguinal. Assim, observa-se que o tumor pode causar alteração na drenagem linfática provocando metástase em linfonodos que normalmente não drenam determinadas mamas, por isso a retirada do linfonodo axilar deve ser incluída como técnica de rotina para permitir melhor estadiamento das neoplasias mamárias de cadelas.(AU)

Mammary tumors research in bitches is important due to their high incidence. The aim of this study was to evaluate the importance of the axillary lymph node as a sentinel lymph node for mammary neoplasms in female dogs. Forty-nine bitches with mammary neoplasia were submitted to total unilateral mastectomy, and the axillary lymph node was identified using the patent blue dye. This lymph node was processed routinely for histopathological analysis and stained with hematoxylin-eosin and by immunohistochemistry (IHC) with cytokeratin antibody (AE1/AE3) to search for metastasis. Eight dogs had axillary lymph node metastases, seven of which were detected by histopathology and by IHC and only one by IHC (micrometastasis). One dog who presented tumor in caudal and inguinal abdominal mammary glands had metastases in the axillary and inguinal lymph nodes. It is concluded that the mammary tumor can cause alteration in lymphatic drainage leading to metastases in lymph nodes which normally do not drain certain glands; so the removal of the axillary lymph node should be included as a routine technique to allow better staging of mammary neoplasms of bitches.(AU)

Caracterização clínica e histopatológica de tumores mamários em cadelas atendidas em Viçosa, MG / Clinical and histopathological characterization of breast tumors in female dogs taken care of in Viçosa, MG

Introdução: a neoplasia da glândula mamária é o tumor mais comum em cadelas. Devido a sua elevada frequência, torna-se necessário investigar os aspectos anátomo-patológicos dessas neoplasias de modo a promover o aumento da longevidade e melhorias na qualidade de vida destes animais. Objetivo: analisar as características clínicas e histopatológicas de tumores mamários em cadelas atendidas em Viçosa, MG. Métodos: trata-se de um estudo descritivo, exploratório, observacional, com abordagem quantitativa, realizada em um laboratório de histopatologia e histologia com 12 cadelas que apresentam tumor mamário. As amostras analisadas foram coletadas no Hospital Veterinário da cidade de Viçosa, MG. Após a fixação, o material foi avaliado macroscopicamente e, em seguida, submetido ao processamento histológico. As preparações histológicas foram analisadas por microscopia óptica. Resultados: no estudo, verificaram-se 58,3% de neoplasias malignas e 33,3% de neoplasias benignas. A maior parte dos tumores da glândula mamária canina foi de comportamento maligno, e o tipo histológico correspondente mais prevalente foi o carcinoma (91,6%). Conclusão: os tipos histológicos malignos de maior ocorrência nas cadelas correspondem ao carcinoma. O seu diagnóstico e terapêutica precoces são importantes na prevenção do desenvolvimento neoplásico nestas cadelas. (AU)

Introduction: mammary gland neoplasm is the most common tumor in bitches. Due to its high frequency, it is necessary to investigate the anatomopathological aspects of these neoplasias in order to promote the increase of longevity and improvements in the quality of life of these animals. Objective: to analyze the clinical and histopathological characteristics of breast tumors in female dogs taken care of in Viçosa, MG. Method: this is a descriptive, exploratory, observational study with a quantitative approach, carried out in a laboratory of histopathology and histology with 12 female dogs presenting breast tumor. The analyzed samples were collected at the Veterinary Hospital from city of Viçosa, MG. After fixation, the material was macroscopically evaluated and then subjected to histological processing. Histological preparations were analyzed by optic microscopy. Results: in the study, 58.3% of malignant neoplasias were observed, accompanied by 33.3% of benign neoplasy. Most tumors of the canine mammary gland were malignant and the most common histological prevalent was carcinoma (91.6%). Conclusion: the most frequent malignant histological types in dogs correspond to carcinoma. Its early diagnosis and therapy is important in preventing neoplasm development in these bitches. (AU)

Tumorsphere formation and cancer stem cell characterization of REM134 canine mammary carcinoma cells / 대한수의학회지

Canine mammary tumors are among the most frequently observed cutaneous tumors in female dogs. Cancer stem cells (CSCs), referred to as tumor-initiating cells, are thought to have properties similar to normal stem cells such as the ability to self-renewal and to differentiate into various cell types. Biological understanding of CSCs and the critical pathways involved in their maintenance are important in research and therapy for mammary tumors. We conducted the present study on sphere formation from REM134 cells by using methylcellulose to produce tumorspheres on a large scale and compared the specific markers of the spheres-formed and plating-cultured REM134 cells. The results revealed that the tumorspheres cultured in methylcellulose had higher seeding density and improved morphology compared to those produced in normal sphere formation medium. Expression levels of stemness markers and CSC-related markers were higher in tumorsphere-forming cells than in plating-cultured cells. Subsequently, we transplanted the tumorsphere-forming and plating-cultured cells into female nude mice to examine their tumorigenic potential. Tumor volume increased rapidly in mice transplanted with tumorsphere-derived cells compared to plating-cultured cells. We observed a novel sphere-forming condition for REM134 cells and showed that REM134 cell tumorspheres can exhibit improved CSC properties.