Feline Mammary Carcinomas Research Articles

Implementation of Machine Learning-Based System for Early Diagnosis of Feline Mammary Carcinomas through Blood Metabolite Profiling.

Background: Feline mammary carcinoma (FMC) is a prevalent and fatal carcinoma that predominantly affects unspayed female cats. FMC is the third most common carcinoma in cats but is still underrepresented in research. Current diagnosis methods include physical examinations, imaging tests, and fine-needle aspiration. The diagnosis through these methods is sometimes delayed and unreliable, leading to increased chances of mortality. Objectives: The objective of this study was to identify the biomarkers, including blood metabolites and genes, related to feline mammary carcinoma, study their relationships, and develop a machine learning (ML) model for the early diagnosis of the disease. Methods: We analyzed the blood metabolites of felines with mammary carcinoma using the pathway analysis feature in MetaboAnalyst software, v. 5.0. We utilized machine-learning (ML) methods to recognize FMC using the blood metabolites of sick patients. Results: The metabolic pathways that were elucidated to be associated with this disease include alanine, aspartate and glutamate metabolism, Glutamine and glutamate metabolism, Arginine biosynthesis, and Glycerophospholipid metabolism. Furthermore, we also elucidated several genes that play a significant role in the development of FMC, such as ERBB2, PDGFA, EGFR, FLT4, ERBB3, FIGF, PDGFC, PDGFB through STRINGdb, a database of known and predicted protein-protein interactions, and MetaboAnalyst 5.0. The best-performing ML model was able to predict metabolite class with an accuracy of 85.11%. Conclusion: Our findings demonstrate that the identification of the biomarkers associated with FMC and the affected metabolic pathways can aid in the early diagnosis of feline mammary carcinoma.

Evaluation of Erythrocytes Indices, Platelet Indices and Complete Blood Count in Feline Mammary Carcinomas

The aim of this study was to evaluate the differences in the platelet (PLT) indices and complete blood count (CBC) parameters between the cats with mammary tumor and healthy individuals. Also, the differences in above mentioned parameters are going to be investigated in cats with mammary tumors with regard to clinicopathological characteristics of the primary tumor. A total of 44 female cats were included in the study. The study groups consisted of cats with mammary tumors (Group MT, n=22) and healthy cats presented for neutering (Group H, n=22). The ages of the cats were ranged between 5-15 years. All data on CBC, thoracic radiography, clinical examination findings and histopathology were obtained from the the patient archive in the animal hospital automation system. While the highest red blood cell (RBC) and hemoglobulin (HGB) levels were observed in Group H, Group MT had the highest white blood cell (WBC), mean platelet volume (MPV) and plateletcrit (PCT) levels. The mean corpuscular volume (MCV) level in T1 was significantly lower than in T2-T3. The MCV level in G1-G2 tended to be higher compared to G3. In Group MT, CBC parameters were not significantly different related to the presence of metastasis, presence of ulceration and inflammation on the tumor. It was concluded that evaluation of CBC and PLT indices in cats with mammary tumors would be useful in understanding the hematological effects of the disease and tumor characteristics (tumor size and histological grade).

Distribution of Inflammatory Infiltrate in Feline Mammary Lesions: Relationship With Clinicopathological Features.

Inflammation is a frequent finding in feline mammary neoplasms. Recent research suggests that the presence and location of tumour-associated immune cells might play a significant role in the clinical outcome of feline mammary carcinomas. The present study aimed to characterise the overall inflammatory infiltrates in healthy, hyperplastic/dysplastic, benign and malignant lesions of the feline mammary gland, and to evaluate its association with clinicopathological features. Perilesional and intralesional inflammatory foci were evaluated in 307 lesions from 185 queens, and categorised according to its distribution and intensity. The presence, location and density of tertiary lymphoid structures were also assessed. A control group included 24 queens without mammary changes. The presence of intralesional and perilesional inflammatory infiltrate was observed in a majority of the lesions (80.8% and 90.2%, respectively), but differed according to the type of mammary lesion, being more remarkable in malignant neoplasms. Only scarce individual cells were observed in 28.1% of the normal mammary glands. Data analysis revealed statistically significant associations (p < 0.05) between the presence of a more prominent intralesional and perilesional inflammatory reaction and several clinicopathological features associated with worse prognosis, including clinical stage, tumour size, mitotic count, lymphovascular invasion and lymph node metastasis. Furthermore, tertiary lymphoid structures were significantly more frequent in tumours with an infiltrative growth and lymph node metastasis. According to our results, the inflammatory reaction present in different types of feline mammary lesions is associated with the development of more aggressive tumours.

Reduction of phosphorylated signal transducer and activator of transcription-5 expression in feline mammary carcinoma.

Signal transducers and activators of transcription (STATs) are a family of transcription factors involved in various normal physiological cellular processes. Moreover, STATs have been recently identified as novel therapeutic targets for various human tumors. STAT3, STAT5a, and STAT6 have been suggested to be involved in tumorigenesis in human breast cancer. Owing to the similarity between feline mammary carcinomas (FMCs) and human breast cancers, these factors may play an important role in FMCs. However, studies on the expression of STATs in animal tumors are limited. Therefore, in this study, we aimed to characterize the expression of total STAT5 (tSTAT5) and phosphorylated STAT5 (pSTAT5) in FMCs, feline mammary adenomas, non-neoplastic proliferative mammary gland lesions, and normal feline mammary glands using immunohistochemistry. High expression of tSTAT5 was observed in the cytoplasm of all the samples assessed in this study. Moreover, high expression of tSTAT5 was observed in the nucleus; however, its levels varied depending on the lesion. The percentage of pSTAT5-nuclear positive cells varied among normal feline mammary glands (40.1 ± 25.1%), and non-neoplastic lesions, including mammary hyperplasia (43.2 ± 28.6%) and fibroadenomatous changes (18.0 ± 13.6%). Moreover, the percentage of pSTAT5-nuclear-positive cells in feline mammary adenomas was 24.5 ± 19.2%, which was significantly reduced in feline mammary carcinomas (2.4 ± 5.6%), regardless of histopathological subtype. This study suggests that decreased STAT5 activity may be involved in the development and malignant progression of feline mammary carcinomas.

Platelet count and MCHC as independent prognostic markers for feline mammary carcinomas

Mammary neoplasms are common in felines species and represent a significant disease for its unfavorable prognosis. Changes in the blood count and serum biochemical profile of these patients have potential as non-invasive prognostic markers prior to mastectomy, however, they are poorly described in literature. In this study univariate and multivariate analyses were performed using these factors to determine the effect of each parameter on the one-year survival time after the surgical procedure in these animals. The median overall survival (OS) and the disease-free survival (DFS) were 365 and 242 days, respectively. In univariate analysis, values within the reference range of monocyte, platelet and creatinine counts were identified as significant prognostic factors for OS and only creatinine was significant for DFS (P < 0.05). In the multivariate analysis, platelets and mean corpuscular hemoglobin concentration (MCHC) remained independent prognostic factors for OS. The results presented suggest that monocytes, platelets and creatinine may be important non-invasive pre-surgical prognostic markers, and that platelet count and MCHC are independent prognostic markers for feline mammary carcinomas (FMC). The correlation between such alterations is of important relevance for veterinary oncology, and prospective studies are needed to validate their clinical use and that platelet count and MCHC are independent prognostic markers for FMC. The results found in this study can also be studied in human medicine, regarding blood markers in human breast cancer (HBC).

Topoisomerase IIα immunoexpression in feline mammary carcinomas: A correlation with Ki67 immunoexpression and the mitotic count

The aim of the study was to compare the immunohistochemical expression of topoisomerase IIα protein (Topo IIα) with Ki67 expression and mitotic count in feline mammary carcinomas (FMCs). Topo IIα is considered as a proliferation indicator as well as a molecular target of anthracycline chemotherapy. The studied material included 70 FMCs from female cats treated with mastectomy. Primary mouse monoclonal antibodies directed against Topo IIα and Ki67 were used in immunohistochemical reactions. The number of mitotic figures was counted at 400× magnification in a field of 2.37 mm2. Immunohistochemical reaction for Topo IIα occurred in cell nuclei. The Topo IIα index ranged from 6.12% to 54.60% and was positively correlated with the values of the Ki67 index (r = 0.7193) and the mitotic count (r = 0. 2858). This indicates the potential possibility of use of the immunohistochemical expression of Topo IIα to assess the rate of proliferation in FMCs. The wide range of expression of Topo IIα in individual tumorus found in the conducted studies allows us to hypothesize that its assessment could be used as a predictive marker in chemotherapy of FMCs with the use of anthracyclines. However, this requires confirmation in clinical trials.

Abstract P3-08-02: Prospective Use of Feline Mammary Carcinomas to Study MiR-10b and Metastasis

Abstract Despite many advances in cancer treatment, metastatic disease is estimated to be responsible for 90% of all cancer-related deaths. Current treatments for metastatic disease target various aspects of carcinogenesis but not specifically the metastatic process, representing a major unmet clinical need. MicroRNA-10b, a small non-coding RNA, offers tremendous potential as a treatment target for metastatic disease. It is implicated in invasion, migration, and viability of metastatic cells across a variety of cancer types, and it is upregulated in metastases compared to their matched primary tumor, establishing miR-10b as a potential treatment target unique to metastatic niche. We have previously developed a therapeutic targeting miR-10b in metastases and tested it in murine models of metastatic breast cancer. This therapeutic, consisting of an anti-miR-10b antisense oligonucleotide conjugated to iron oxide-based nanoparticles, prevents metastasis and eradicates pre-existing metastases in murine breast cancer models. With an outlook to clinical translation of our approach, we seek to test our therapeutic strategy in larger animal models. Feline mammary carcinomas are considered by most to be the best large animal model for human breast cancer due to similarities such as relative age of onset, histopathology, metastatic patterns, and treatment response. To support the use of this model with our therapeutic, we investigated the characteristics of miR-10b expression in spontaneous metastatic breast cancer in companion cats. Archival blocks of matched primary tumors and metastatic lymph nodes from companion cats diagnosed with mammary carcinoma (n=9, 44%TNBC, 56%HER2+) were obtained from the tissue bank of the Michigan State University (MSU) Veterinary Diagnostic Laboratory (VDL). Tissues were analyzed for miR-10b and its target HOXD10 expression using qRT-PCR and in situ hybridization. qRT-PCR revealed that miR-10b expression was significantly upregulated in 55.5% of lymph node metastases compared to their matched primary tumor, mirroring findings in human metastatic cancer. This was validated by qRT-PCR for HOXD10 gene expression (a direct target of miR-10b), which was significantly downregulated in these metastases compared to their matched primary tumor. In situ hybridization demonstrated that miR-10b expression was increased at the invasive edge of tumors and in actively invading cells, suggesting miR-10b plays a similar role in invasion in feline breast cancer as it does in human breast cancer. Altogether, these findings support the use of feline mammary carcinomas as a model of human breast cancer and as an excellent candidate for treatment with our therapeutic. Citation Format: Alan Halim, N. Anna Savan, Paulo Vilar Saavedra, Vilma Yuzbasiyan-Gurkan, Matti Kiupel, Lorenzo Sempere, Anna Moore. Prospective Use of Feline Mammary Carcinomas to Study MiR-10b and Metastasis [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-08-02.

TIM-3 Is a Potential Immune Checkpoint Target in Cats with Mammary Carcinoma.

Recent findings in human breast cancer (HBC) indicate that T-cell immunoglobulin and mucin-domain-containing molecule-3 (TIM-3)-targeted therapies may effectively activate anticancer immune responses. Although feline mammary carcinoma (FMC) is a valuable cancer model, no studies on TIM-3 have been developed in this species. Thus, we evaluated the expression of TIM-3 by immunohistochemistry in total (t), stromal (s), and intra-tumoral (i) tumor-infiltrating lymphocytes (TILs) and in cancer cells, of 48 cats with mammary carcinoma. In parallel, serum TIM-3 levels were quantified using ELISA and the presence of somatic mutations in the TIM-3 gene was evaluated in 19 tumor samples. sTILs-TIM3+ were more frequent than iTILs-TIM-3+, with the TIM-3 ex-pression in sTILs and cancer cells being associated with more aggressive clinicopathological features. In contrast, the TIM-3 expression in iTILs and tTILs was associated with a more benign clinical course. Moreover, the serum TIM-3 levels were lower in animals with FMC when compared to healthy animals (p &lt; 0.001). Only one somatic mutation was found in the TIM-3 gene, at intron 2, in one tumor sample. Altogether, our results suggest that the expression of TIM-3 among TILs subpopulations and cancer cells may influence the clinical outcome of cats with FMC, in line with the previous reports in HBC.

Transcription profiling of feline mammary carcinomas and derived cell lines reveals biomarkers and drug targets associated with metabolic and cell cycle pathways

The molecular heterogeneity of feline mammary carcinomas (FMCs) represents a prognostic and therapeutic challenge. RNA-Seq-based comparative transcriptomic profiling serves to identify recurrent and exclusive differentially expressed genes (DEGs) across sample types and molecular subtypes. Using mass-parallel RNA-Seq, we identified DEGs and performed comparative function-based analysis across 15 tumours (four basal-like triple-negative [TN], eight normal-like TN, and three luminal B fHER2 negative [LB fHER2−]), two cell lines (CL, TiHo-0906, and TiHo-1403) isolated from the primary tumours (LB fHER2−) of two cats included in this study, and 13 healthy mammary tissue controls. DEGs in tumours were predominantly upregulated; dysregulation of CLs transcriptome was more extensive, including mostly downregulated genes. Cell-cycle and metabolic-related DEGs were upregulated in both tumours and CLs, including therapeutically-targetable cell cycle regulators (e.g. CCNB1, CCNB2, CDK1, CDK4, GTSE1, MCM4, and MCM5), metabolic-related genes (e.g. FADS2 and SLC16A3), heat-shock proteins (e.g. HSPH1, HSP90B1, and HSPA5), genes controlling centrosome disjunction (e.g. RACGAP1 and NEK2), and collagen molecules (e.g. COL2A1). DEGs specifically upregulated in basal-like TN tumours were involved in antigen processing and presentation, in normal-like TN tumours encoded G protein-coupled receptors (GPCRs), and in LB fHER2− tumours were associated with lysosomes, phagosomes, and endosomes formation. Downregulated DEGs in CLs were associated with structural and signalling cell surface components. Hence, our results suggest that upregulation of genes enhancing proliferation and metabolism is a common feature among FMCs and derived CLs. In contrast, the dissimilarities observed in dysregulation of membrane components highlight CLs’ disconnection with the tumour microenvironment. Furthermore, recurrent and exclusive DEGs associated with dysregulated pathways might be useful for the development of prognostically and therapeutically-relevant targeted panels.

The Landscape of Tumor-Infiltrating Immune Cells in Feline Mammary Carcinoma: Pathological and Clinical Implications.

Feline mammary carcinoma (FMC) shares key molecular and clinicopathological features with human breast cancer. We have herein studied the inflammatory infiltrate of FMC in order to uncover potential therapeutic targets and prognostic markers. To this end, the expression of different markers (CD3, CD4, CD8, CD20, CD56, FoxP3, CD68 and CD163) was analyzed in total, stromal (s) and intratumoral (i) tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs), in 73 feline mammary carcinomas. The results revealed that higher percentages of sCD8+ TILs were associated with longer disease-free survival (p = 0.05) and overall survival (p = 0.021). Additionally, higher percentages of iCD4+ TILs correlated with positive lymph node status (p = 0.003), whereas CD163+ TAMs were associated with undifferentiated tumors (p = 0.013). In addition, sCD3+ (p = 0.033), sCD8+ (p = 0.044) and sCD68+ (p = 0.023) immune cells were enriched in triple negative normal-like carcinomas compared to other subtypes. Altogether, our results suggest that specific subsets of immune cells may play a major role in clinical outcome of cats with mammary carcinoma, resembling what has been reported in human breast cancer. These data further support the relevance of the feline model in breast cancer studies.

Immunohistochemical Expression of p62 in Feline Mammary Carcinoma and Non-Neoplastic Mammary Tissue.

Simple SummaryThe p62 protein, also called sequestosome 1 (SQSTM1), is a ubiquitin-binding scaffold protein. The expression of p62 was statistically higher in carcinoma compared to non-neoplastic mammary glands. Our results, although preliminary, are similar to the results of breast cancer, therefore, also in the cat, p62 could be considered a possible oncotarget.The p62 protein, also called sequestosome 1 (SQSTM1), is a ubiquitin-binding scaffold protein. In human oncology, although the interest in the function of this protein is recent, the knowledge is now numerous, but its role in tumorigenesis is not yet clear. This preliminary study aims to evaluate the immunohistochemical expression of p62 in 38 cases of feline mammary carcinoma with different grades of differentiation and in 12 non-neoplastic mammary gland tissues, to assess the expression level and a possible correlation with malignancy. The expression of p62 was statistically higher in carcinoma compared to non-neoplastic mammary glands: 28 feline mammary carcinomas (73.7%) had a high p62 expression score, three (7.9%) had a moderate expression, while seven cases (18.4%) had a low expression. The grade of the differentiation of the carcinoma was not correlated with the p62 expression. This study represents the first approach in feline oncology that correlates p62 expression in feline mammary carcinoma. Our results, although preliminary, are similar to the results of human breast cancer, therefore, also in the cat, p62 could be considered a possible oncotarget.

Infiltrating mammary carcinoma in a cat with a congenital disorder: prognostic interest of histological examination

This report describes the handling and clinical evolution of a malignant feline mammary carcinoma (FMC) in an eight-year-old female crossbred cat with a congenital disorder. Hence, the efficacy of tumor mass removal and the case prognosis was established by postoperative routine histological examination. A 6 cm diameter lump in the left thoracic mammary gland of multinodular appearance and purulent exudate with a reddish hue was excised after the entire mastectomy. The histopathological analysis showed the presence of numerous lymphovascular tumor emboli and frequently mitotic cells with hyperchromatic nuclei. These were consistent with an aggressive malignancy with a poor prognosis explaining the patient's death within 7 weeks after surgery. Histology and cytology findings are of critical importance to clinicians in the management of the most common mammary malignancies in cats, to provide the best possible relief to animals with life-threatening cancer. It could also serve as a cancer model for advancing knowledge in congenitally affected humans.

Tertiary Lymphoid Structures in Feline Mammary Carcinomas: High Frequency and Poor Prognostic Value

Tertiary Lymphoid Structures in Feline Mammary Carcinomas: High Frequency and Poor Prognostic Value

Comparative gene expression study highlights molecular similarities between triple negative breast cancer tumours and feline mammary carcinomas.

Triple negative breast cancer (TNBC) is a rare, highly metastatic subtype of breast cancer that typically develops tumours of a high histological grade. As TNBC is negative for the oestrogen, progesterone and HER2 receptors it is also not eligible for targeted hormonal therapies. Therefore, those diagnosed with TNBC are faced with a very poor prognosis. Feline mammary carcinomas (FMCs) have been shown to share key characteristics of TNBC and are being investigated as novel animal models of this disease. A study by Granados‐Soler et al., investigating prognostic markers of FMCs provided the basis of this research, and their prognostic value in TNBC was evaluated using a ‘data‐mining’ research approach. Overall, the comparative genomic aspect of this research identified several potential prognostic markers translatable across TNBC and FMCs. These prognostic markers warrant further investigation in comparative oncology studies.

VISTA Is a Diagnostic Biomarker and Immunotherapy Target of Aggressive Feline Mammary Carcinoma Subtypes.

Simple SummaryMammary tumors are common in cats, showing aggressive behavior and few therapeutic options. Recently, feline mammary carcinomas have become a reliable cancer model for human breast cancer studies, due to the similarities between the two species. Thus, the identification of new tumor biomarkers and therapeutic targets to improve cat’s prognosis is needed. VISTA is an important immune checkpoint protein that has gained importance over the past few years in women’s cancers. In this study, the serum VISTA levels and tumor expression were analyzed in cats with mammary tumors, being correlated with other immune checkpoints. In the diseased animals, VISTA is overexpressed in more aggressive tumor subtypes (HER2-positive and triple-negative), showing a positive correlation with the expression of VISTA in tumor-infiltrating lymphocytes, and is associated with an immunosuppressive status, suggesting that VISTA could be a promising non-invasive prognostic biomarker and therapeutic target in cats with mammary carcinomas, as reported in humans.Feline mammary carcinoma (FMC) is a common neoplasia, showing aggressive clinicopathological features, without viable therapeutic options. The study of tumor microenvironment has gained importance, due to the ability to control tumor progression by regulating the immune response. Considering the lack of knowledge, feline serum VISTA levels from cats with mammary carcinoma were compared with healthy controls, and with serum levels of PD-1/PD-L1, CTLA-4, LAG-3, IL-6, and TNF-α. In parallel, VISTA tumor expression was evaluated in FMC samples. The obtained data revealed that serum VISTA levels were significantly higher in cats presenting HER2-positive (p = 0.0025) or triple-negative subtypes (p = 0.0019), with higher serum levels in luminal A (p = 0.0025) correlated to the presence of metastasis (p = 0.0471). Furthermore, in HER2-positive or triple-negative tumors, correlations were obtained between serum VISTA levels and the serum levels of the above-mentioned molecules. In tumors, VISTA expression revealed a stronger intensity in cancer cells, when compared to TILs (p < 0.0001). Stratifying the samples by subtypes, a higher number of VISTA-positive TILs was observed in the HER2-positive subtype, compared with triple-negative tumors (p = 0.0138). In conclusion, results support the development of therapeutic strategies for HER2-positive and triple-negative FMC subtypes, reinforcing the use of cats as a human oncology model.

Pathological Features and Molecular Phenotype of MMTV Like-Positive Feline Mammary Carcinomas.

Simple SummaryMouse mammary tumour virus-like (MMTV-like) is suspected to be involved in human breast cancer and feline mammary carcinomas (FMCs). We previously reported the identification of MMTV-like sequences and viral protein in six of 78 FMCs collected in Tuscany, Italy. To corroborate this finding, FMCs samples collected from a different geographic area were investigated. MMTV-like sequences and p14 protein were identified in three of 24 FMCs collected at the University of Bologna, one tubular carcinoma, one tubulopapillary carcinoma and one ductal carcinoma. All the examined FMCs from Pisa and Bologna were submitted to immunohistochemistry for molecular phenotype characterization. Of the nine positive FMCs, six were basal-like and three luminal-like. This study highlights the presence of MMTV-like sequences and protein in FMCs of different geographic areas. The characterization of molecular phenotype could contribute to understand the possible role of MMTV-like virus in FMC biological behaviour.In the last few years MMTV-like nucleotide sequences were detected in some feline and canine mammary tumours. Due to the confirmed role of cats in the epidemiology of the MMTV-like virus, the aim of this study was to investigate the main pathological features of positive feline mammary carcinomas (FMCs). Twenty-four FMCs were collected at the University of Bologna, submitted to laser microdissection and analysed by nested fluorescence-PCR using primer sets specific for MMTV env sequence. For immunohistochemistry, an antibody against MMTV protein 14 (p14) was used. MMTV-like sequences were detected in three out of 24 FMCs (12.5%), one tubular carcinoma, one tubulopapillary carcinoma and one ductal carcinoma. All PCR-positive tumours were also positive for p14. Multiple nucleotide alignment has shown similarity to MMTV ranging from 98% to 100%. All the 102 examined FMCs were submitted to immunohistochemistry for molecular phenotyping. Of the nine MMTV-like positive FMCs, six were basal-like and three luminal-like. Our results demonstrate MMTV-like sequences and protein in FMCs of different geographic areas. Molecular phenotyping could contribute to understand the possible role of MMTV-like virus in FMC tumor biology.

Emerging Biomarkers and Targeted Therapies in Feline Mammary Carcinoma.

Feline mammary carcinoma (FMC) is a common aggressive malignancy with a low survival rate that lacks viable therapeutic options beyond mastectomy. Recently, increasing efforts have been made to understand the molecular mechanisms underlying FMC development, using the knowledge gained from studies on human breast cancer to discover new diagnostic and prognostic biomarkers, thus reinforcing the utility of the cat as a cancer model. In this article, we review the current knowledge on FMC pathogenesis, biomarkers, and prognosis factors and offer new insights into novel therapeutic options for HER2-positive and triple-negative FMC subtypes.

High Drug Resistance in Feline Mammary Carcinoma Cell Line (FMCm) and Comparison with Human Breast Cancer Cell Line (MCF-7)

Simple SummaryThe repurposing and combination of drugs are important therapeutic strategies in cancer therapy, being important for combating drug resistance and improving therapeutical regimens. This paper outlines the use of candidate drugs that are to be repurposed, and combines clinically approved drugs in breast cancer, aiming to understand the response of feline mammary carcinoma cells to this therapeutic approach, previously applied in human breast cancer cells. By using cell viability assays, we revealed that feline mammary carcinoma cells were highly resistant to these tested approaches, contrasting with human breast cancer cells.Drug repurposing and drug combination are important therapeutic approaches in cancer therapy. Drug repurposing aims to give new indications to drugs, rather than the original indication, whereas drug combination presupposes that the effect that is obtained should be more beneficial than the effect obtained by the individual drugs. Previously, drug repurposing and the combination of different drugs was evaluated in our research group against human breast cancer cells (MCF-7 cells). Our results demonstrated that the response obtained through the combination of drugs, when compared with the single drugs, led to more synergic responses. Therefore, using potential drugs for repurposing, combined with a reference drug in breast cancer (5-Fluorouracil), was the major aim of this project, but for the first time using the feline mammary carcinoma cell line, FMCm. Surprisingly, the feline neoplastic cells demonstrated considerable resistance to the drugs tested in isolation, and the combination was not effective, which contrasted with the obtained MCF-7 cells’ response.

The evaluation of non-anesthetic computed tomography for detection of pulmonary parenchyma in feline mammary gland carcinoma: a preliminary study

BackgroundThoracic radiography in awake cats is a common procedure for the evaluation of pulmonary metastasis in feline mammary gland carcinoma (MGC). However, due to poor sensitivity, computed tomography (CT) is progressively taking its place. To perform CT in animals, general anesthesia is normally preferred but can cause lung atelectasis, affecting lung interpretation. Besides, MGC is often found in senile cats that are concurrently affected with other diseases, increasing anesthetic risk. Therefore, this study was aimed at comparing the effect of anesthesia on lung atelectasis observed through CT in clinically healthy cats and comparing the feasibility of non-anesthetic CT with non-anesthetic radiography in the detection of lung lesions in feline MGC. Thoracic CTs from anesthetized, clinically healthy cats and non-anesthetized either clinically healthy cats or MGC-affected cats were reviewed. In clinically healthy cats, motion artifacts and characteristics of lung atelectasis were observed and compared. In MGC-affected cats, motion artifacts were observed and compared to clinically healthy cats, and the number of MGC-affected cats, the number and characteristics of lung lesions were compared between non-anesthetic thoracic CT and radiography.ResultsAnesthesia significantly increased lung CT attenuation (P = 0.0047) and was significantly correlated with lung atelectasis (OR = 15; CI 2.02–111.18; P = 0.0081), particularly of the cranial lung lobe. Nonetheless, significantly higher motion artifacts in the caudal thoracic area were found in non-anesthetized healthy cats (P = 0.0146), but comparable low motion artifacts were observed in anesthetized healthy and MGC-affected cats. Non-anesthetic CT revealed higher numbers of MGC-affected cats and pulmonary nodules with a significantly lower nodular diameter (P = 0.0041) than those observed on radiographs. The smallest nodular diameters detected on radiographs and CT were 2.5 and 1.0 mm, respectively. Furthermore, CT showed additional information such as intra-thoracic lymphadenopathy, that could not be seen on radiographs.ConclusionsDespite the motion artifacts, CT without anesthesia is a sensitive technique as it provides better lung inflation. Furthermore, compared to non-anesthetic radiography, non-anesthetic CT provided more information such as higher number of pulmonary nodules of a smaller size, including more distinct intra-thoracic lesions, such as lymphadenopathy, in MGC-affected cats.

The implication of autoantibodies in early diagnosis and monitoring of plasmonic photothermal therapy in the treatment of feline mammary carcinoma

Feline mammary carcinoma (FMC) shows great similarities to human breast cancer in the cellular and molecular levels. So, in cats as in humans, the role of immune responses is indicated to detect and follow up the development of tumors. As a new breast cancer therapeutic approach, Plasmonic Photothermal Therapy (PPTT) is an effective localized treatment for canine and feline mammary-carcinoma. Its systemic effect has not been inquired yet and needs many studies to hypothesis how the PPTT eradicates tumor cells. In this study, it is the first time to detect (P53, PCNA, MUC-1, and C-MYC) feline autoantibodies (AAbs), study the relationship between PCNA AAbs and mammary-tumors, and investigate the effect of PPTT on the humoral immune response of cats with mammary-carcinoma through detection of AAbs level before, during, and after the treatment. The four-AAbs panel was evaluated in serum of normal and clinically diagnosed cats with mammary tumors using Enzyme-Linked Immunosorbent Assay. The panel showed 100% specificity and 93.7% sensitivity to mammary tumors. The panel was evaluated in PPTT monotherapy, mastectomy monotherapy, and combination therapy. PPTT monotherapy decreased AAbs level significantly while mastectomy monotherapy and combination therapy had a nonsignificant effect on AAbs level.