Normal Mammary Gland Tissue Research Articles

Evaluation of MCL-1 as a prognostic factor in canine mammary gland tumors.

Myeloid cell leukemia-1 (MCL-1), which belongs to the anti-apoptotic B cell lymphoma-2 family protein, is overexpressed in various cancers and is associated with cell immortality, malignant transformation, chemoresistance, and poor prognosis in humans. However, the significance of MCL-1 in canine mammary gland tumors (MGTs) remains unknown. This study aimed to examine MCL-1 expression in normal canine mammary glands and tumors and to assess its correlation with clinical and histologic variables. In total, 111 samples were examined, including 12 normal mammary gland tissues, 51 benign MGTs, and 48 malignant MGTs. Immunohistochemistry revealed that 53% of benign tumors and 75% of malignant tumors exhibited high MCL-1 expression, whereas only 8% of normal mammary glands exhibited high MCL-1 expression. High MCL-1 expression correlated with tumor malignancy (p < 0.001), large tumor size (> 3 cm) (p = 0.005), high Ki-67 expression (p = 0.046), and metastasis (p = 0.027). Survival curve analysis of dogs with malignant MGTs demonstrated a significant association between high MCL-1 expression and shorter median overall survival (p = 0.027) and progression-free survival (p = 0.014). Our study identified MCL-1 as a prognostic factor and potential therapeutic target in canine MGTs.

Defining and targeting macrophage heterogeneity in the mammary gland and breast cancer.

Macrophages are innate immune cells that are associated with extensive phenotypic and functional plasticity and contribute to normal development, tissue homeostasis, and diseases such as cancer. In this review, we discuss the heterogeneity of tissue resident macrophages in the normal mammary gland and tumor-associated macrophages in breast cancer. Tissue resident macrophages are required for mammary gland development, where they have been implicated in promoting extracellular matrix remodeling, apoptotic clearance, and cellular crosstalk. In the context of cancer, tumor-associated macrophages are key drivers of growth and metastasis via their ability to promote matrix remodeling, angiogenesis, lymphangiogenesis, and immunosuppression. We identified and summarized studies in Pubmed that describe the phenotypic and functional heterogeneity of macrophages and the implications of targeting individual subsets, specifically in the context of mammary gland development and breast cancer. We also identified and summarized recent studies using single-cell RNA sequencing to identify and describe macrophage subsets in human breast cancer samples. Advances in single-cell RNA sequencing technologies have yielded nuances in macrophage heterogeneity, with numerous macrophage subsets identified in both the normal mammary gland and breast cancer tissue. Macrophage subsets contribute to mammary gland development and breast cancer progression in differing ways, and emerging studies highlight a role for spatial localization in modulating their phenotype and function. Understanding macrophage heterogeneity and the unique functions of each subset in both normal mammary gland development and breast cancer progression may lead to more promising targets for the treatment of breast cancer.

Usability of serum hedgehog signalling proteins as biomarkers in canine mammary carcinomas

BackgroundThe hedgehog signalling pathway has been implicated in tumourigenesis and progression of many tumour types. This pathway has recently emerged as a therapeutic target, and inhibitors of hedgehog signalling have gained considerable attention. In dogs, the roles of hedgehog signals in several types of tumours have been investigated, but their relationship with canine mammary gland tumours (MGTs) has not been established. This study aimed to evaluate the expression of sonic hedgehog (SHH) and glioma-associated oncogene 1 (GLI-1) in the serum and mammary tumour tissues of dogs.ResultsSHH and GLI-1 protein expression levels were significantly higher in MGT tissues than in normal mammary gland tissues, as well as in malignant MGT specimens than in benign MGT specimens. Serum levels of SHH and GLI-1 were higher in MGT patients than in healthy controls (p < .001 and .001, respectively). Serum SHH level showed a statistically significant relationship with metastatic status (p = .01), and serum GLI-1 level showed a statistically significant relationship with histologic grade (p = 0.048) and metastatic status (p = 0.007). Serum hedgehog signalling protein levels were not significantly associated with breed size, sex, tumour size, or histologic type.ConclusionsHedgehog signalling protein expression in canine MGT tissue and serum differed according to the histological classification (benign and malignant) and metastatic status, indicating a relationship between the hedgehog signalling pathway and canine MGT. Thus, the hedgehog signalling pathway may serve as a new biomarker and therapeutic target in canine MGT patients.

Sirtuin 1 Expression in Canine Mammary Tumors: A Pilot Study.

Sirtuin 1 (SIRT1) is a protein involved in aging, cell protection, and energy metabolism in mammals. Recently, SIRT1 has been intensively studied in medical oncology, but the role of SIRT1 is still controversial, as it has been proposed as both an oncogene and a tumor suppressor. The aim of this study is to investigate the expression of SIRT1 by immunohistochemistry in canine mammary tissues, and by Western blot and immunofluorescence analysis in different canine mammary cell lines. Our results showed a decrease in SIRT1 expression from normal mammary gland tissue, and from benign and well-differentiated malignant tumors (G1) to less differentiated ones (G2-G3). Furthermore, a shift in the subcellular localization of SIRT1 from the nucleus to the cytoplasm was observed in less differentiated malignant tumors. However, further studies are needed to investigate the subcellular localization of SIRT1 in canine cancer cells and the role it may play in oncogenesis in animals.

Upregulation of SLUG expression in canine mammary gland tumors and its prognostic significance

BackgroundSLUG (also known as snai2), which is a transcription factor in epithelial–mesenchymal transition (EMT), plays an important role in tumorigenesis. Several human studies have revealed that SLUG expression downregulates E-cadherin activity to induce metastasis and invasion of tumor cells, and its association with tumor mechanisms is under constant evaluation. In clinical veterinary medicine, one study revealed upregulated SLUG expression in canine oral squamous cell carcinoma. However, the association between canine mammary gland tumors (MGT), the most common neoplasm in intact female dogs, and SLUG has not been investigated yet. Therefore, this study aimed to evaluate the differences in SLUG expression among canine normal mammary gland tissue and MGTs using immunohistochemistry. In addition, its prognostic significance was evaluated by analyzing the correlation with the Ki-67 proliferation index and various clinicopathological features.ResultsSLUG expression increased substantially from normal mammary gland tissues to MGTs, especially showing the strongest expression in malignant MGT than in benign MGT. Negative SLUG expression was observed in mostly normal mammary gland tissues, whereas all tissues in malignant MGT showed positive SLUG expression. Furthermore, positive SLUG expression was associated with higher Ki-67 index, larger tumor size (> 3 cm), and metastasis. Kaplan–Meier survival curve analysis revealed that positive SLUG expression was significantly associated with poor overall and disease-free survival.ConclusionsThese results indicate that SLUG is upregulated in canine MGTs and positive SLUG expression is positively correlated with poor prognosis. Thus, SLUG protein can be a novel biomarker and therapeutic target for canine patients with MGT.

Research of the New Biomarkers of Mammary Gland Tumors in Domestic Cats

This article presents the results of the clinical significance study of changes in the activity of adenosine deaminase and the content of polyamines in the blood plasma of cats with mammary gland tumors. In our work, we investigated the activity of the adenosine deaminase gene in the tissues of mammary gland tumors in cats and compared the activity of this gene with normal mammary gland tissue. In the course of this work, we also found out the frequency of occurrence of mammary gland tumors in the population of domestic cats in the Rostov region and evaluated the prognosis of survival after surgical treatment of breast cancer. The incidence of mammary gland tumors was detected, which amounted to 0.4% of the domestic cats who have applied to veterinary clinics in Rostov region, where the cats with mammary gland neoplasms amounted to approximately 400 individuals for every 100,000 animals. These data reflect the importance of the problem of mammary gland tumors and emphasize the need to study the pathophysiological foundations of carcinogenesis in order to create molecular genetic approaches for early diagnosis of mammary gland tumors. The results of the studies showed that the level of expression of the adenosine deaminase gene in the tissues of invasive nonspecific carcinoma and in the tissues of fibroepithelial hyperplasia sharply increases compared to the tissue of a healthy mammary gland, 36 times in the tissues of invasive carcinomas and 131 times in the tissues of fibroepithelial hyperplasia. At the same time, there were no significant differences between the activity of adenosine deaminase in the blood plasma of healthy animals and in the blood plasma of animals with malignant neoplasms of the mammary gland. Measurement of the level of polyamines in the blood of animals showed that the content of putrescine in the erythrocytes of the blood of cats with benign and tumor-like neoplasms of the mammary fibroepithelial hyperplasia significantly increased by 5 times compared with the indicators of the control group. In malignant neoplasms of the mammary gland invasive nonspecific carcinoma, the content of putrescine and spermin in the blood significantly exceeded the control values by 6 and 10 times, respectively.

Clinicopathological Analysis of Expression of Enhancer of Zeste Homologue 2 in Canine Mammary Carcinoma.

IntroductionEnhancer of zeste homologue 2 (EZH2) is the human homologue of Drosophila zeste gene enhancer. The aim of this study was to determine the expression of EZH2 in canine mammary carcinomas (CMCs) and its relationship with clinicopathological features.Material and MethodsThe expression of EZH2 mRNA and protein in 53 CMC tissue and 8 normal mammary gland tissue samples was measured by quantitative real-time PCR and immunohistochemical staining assay, respectively. The relationship between EZH2 protein expression and clinicopathological features was analysed by χ2 test to further explore the clinical significance of EZH2 in CMCs.ResultsCompared with normal mammary gland tissues, EZH2 mRNA expressions were significantly increased in CMC tissues (P < 0.01). Moreover, normal mammary glands did not express the EZH2 protein but carcinomic glands did, and expression increased in CMCs with high histological grades, especially in histological grade II (P < 0.05). However, EZH2 expression was not related to age, tumour size, or metastasis (P > 0.05). The expression of EZH2 in one type of CMC was not significantly different from the expression in any other type (P > 0.05).ConclusionEZH2 is highly expressed in CMCs, indicating that it can be used as a molecular marker for early diagnosis, prognosis, or therapy of CMCs.

High prevalence of somatic PIK3CA and TP53 pathogenic variants in the normal mammary gland tissue of sporadic breast cancer patients revealed by duplex sequencing

The mammary gland undergoes hormonally stimulated cycles of proliferation, lactation, and involution. We hypothesized that these factors increase the mutational burden in glandular tissue and may explain high cancer incidence rate in the general population, and recurrent disease. Hence, we investigated the DNA sequence variants in the normal mammary gland, tumor, and peripheral blood from 52 reportedly sporadic breast cancer patients. Targeted resequencing of 542 cancer-associated genes revealed subclonal somatic pathogenic variants of: PIK3CA, TP53, AKT1, MAP3K1, CDH1, RB1, NCOR1, MED12, CBFB, TBX3, and TSHR in the normal mammary gland at considerable allelic frequencies (9 × 10−2– 5.2 × 10−1), indicating clonal expansion. Further evaluation of the frequently damaged PIK3CA and TP53 genes by ultra-sensitive duplex sequencing demonstrated a diversified picture of multiple low-level subclonal (in 10−2–10−4 alleles) hotspot pathogenic variants. Our results raise a question about the oncogenic potential in non-tumorous mammary gland tissue of breast-conserving surgery patients.

The Relationship Between Microbial Community and Breast Cancer.

Breast cancer (BC) is the most common cancer in women and the leading cause of cancer-related deaths in women worldwide. Recent research studies have shown that the intestinal flora is related to the occurrence and progression of BC. Notably, some evidence identifies a unique microbial community in breast tissue, a site previously thought to be sterile. In addition, breast tumors have their own specific microbial community, distinct from normal mammary gland tissue, and all of them may result from intestinal flora. Some microbial community in breast tissue may lead to the occurrence and development of BC. This review focuses on the relationship between the microbial community and breast cancer, which will lay a solid theoretical foundation for further understanding the local microenvironment of BC and developing effective targeted therapeutic drugs.

Down-expression of klotho in canine mammary gland tumors and its prognostic significance.

Since the discovery of klotho as an anti-aging gene, its association with tumors has been studied. Several previous studies have reported the down-expression of klotho in various human cancers, and much of its mechanism has been revealed. Nonetheless, the significance of klotho in canine mammary gland tumors is not yet known. This study aimed to determine whether klotho is expressed within normal canine mammary glands and whether the expression changes in benign and malignant tumors. Using immunohistochemistry, the experiment was conducted on eight normal canine mammary gland tissues and 55 mammary gland tumor samples. Additionally, the correlation between the Ki-67 proliferation index and clinicopathological features, such as age, tumor size, tumor grade, histologic type, and metastasis, was evaluated. All eight normal mammary gland tissues showed immunohistochemistry expression of klotho, and the expression significantly decreased as malignancy increased. Among the samples, 11% (3/28) of benign tumors and 26% (7/27) of malignant tumors showed negative klotho expression. Furthermore, higher Ki-67 expression, higher grades, and metastasis were confirmed to be associated with the negative klotho expression. Analysis of the survival curve for dogs with malignant tumors revealed that negative klotho expression was significantly associated with poor overall survival and disease-free survival. These results indicate that klotho is expressed in normal canine mammary glands and that negative klotho expression in canine mammary gland tumors is positively correlated with poor prognosis.

Micro RNA differential expression profile in canine mammary gland tumor by next generation sequencing.

Canine mammary gland tumors are very common and represent a potential model of human breast cancer, and microRNA (miRNAs) are promising biomarkers and therapeutic targets for these tumors. Accordingly, we aimed to identify miRNAs differentially expressed in canine mammary gland tumors using next generation sequencing (NGS), with subsequent confirmatory qPCR and target gene analyses. Mammary gland tissue was collected from healthy dogs (n=7) and dogs with suspected tumors (n=80). A subset of samples was analyzed with NGS to identify differentially expressed miRNAs with CLC Genome Workbench. Normal (n=10), tumor-adjacent (n=6), and tumor-bearing (n=76) mammary gland tissue samples were analyzed for the identified miRNAs using qPCR. An in silico analysis (TargetScan) was performed to predict the miRNAs' target genes using gene ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database (DAVID). We identified four miRNAs (cfa-miR-1-3p, cfa-miR-133a-3p, cfa-miR-133b-3p, and cfa-miR-133c-3p) as down regulated in canine mammary gland tumor tissues relative to normal and tumor adjacent tissues. KEGG analysis revealed the potential target genes of cfa-miR-1-3p are related to the Rap1 signaling pathway, adherens junction, and Ras signaling pathway, and those of the miR-133 family are related to the TGF-beta signaling pathway, synaptic vesicle cycle, and sphingolipid signaling pathway. In combination, these target genes are related to the regulation of transcription and DNA binding transcription (GO analysis), and the Hippo signaling pathway, adherens junction, and endocytosis (KEGG analysis). Accordingly, we suggest these four miRNAs are promising potential biomarker candidates for canine mammary gland tumors warranting further investigation.

Interactions between the breast tissue microbiota and host gene regulation in nonpuerperal mastitis

BackgroundNonpuerperal mastitis (NPM) causes considerable psychological distress in females, since it is difficult to diagnose and treat. A spectrum of etiological factors can lead to NPM. However, the pathogenesis of NPM remains unclear. Here, we aimed to dissect the role of host gene–microbe interactions in NPM. MethodsWe compared the breast tissue microbiome between NPM patients and controls using 16S rRNA sequencing. We also compared the gut microbiome between NPM patients and healthy controls. Moreover, we investigated whether the breast tissue microbiome was associated with an altered gut microbiome in patients with NPM. We analyzed differentially expressed genes in inflammatory tissues of mammary gland from patients with NPM and normal mammary gland tissues from patients with benign and non-infectious breast disease by RNA-sequencing (RNA-seq). Lastly, we explored the association of specific bacterial taxa with differential expression of immune-related genes and differences in infiltrating immune cells. ResultsThe breast tissue microbiome from NPM and controls showed significant differences in community composition. The breast tissue shared a relatively small proportion of bacterial communities with the gut in patients with NPM. Ruminococcus (family Ruminococcaceae) of breast tissue was positively correlated with the differentially expression of immune-related genes between NPM patients and controls, including antigen processing and presentation genes (ICAM1, LGMN, THBS1, TAP1, HSPA1B and HSPA1A), cytokine receptor gene IL15RA, and chemokine gene CCN1. Rhizobium of breast tissue was negatively correlated with the differentially expression of the antigen processing and presentation gene HSPA6 between NPM patients and controls. We also found that Ruminococcus (family Ruminococcaceae), Coprococcus, and Clostridium of breast tissue positively correlated with the difference of CD8+ T cells between NPM patients and controls. ConclusionsWe preliminarily explored the potential role of host–microbe interactions in NPM. We demonstrate cross-talk between the breast tissue microbiome and the gut microbiome in patients with NPM. We suggest that NPM microbiome composition influences the immune microenvironment of the disease by affecting the transcriptome. This is an exploratory study and further investigation of host–microbe interactions and its potential mechanism in NPM development are warranted.

Reduced hyaluronan cross-linking induces breast cancer malignancy in a CAF-dependent manner

Hyaluronan (HA) cross-linking is a conformational state of HA, a covalent complex between HA and heavy chains (HCs) from inter-α-trypsin inhibitor (I-α-I) mediated by tumor necrosis factor-induced protein 6 (TSG6). Cross-linked HA has been identified as a protective factor in physiological and inflammatory conditions. However, the state of HA cross-linking in tumor microenvironment has not been fully elucidated. As a major constituent of the extracellular matrix (ECM), HA is mainly synthesized by cancer-associated fibroblasts (CAFs). Our study aimed to clarify the role of HA cross-linking in breast cancer malignancy. Compared to normal mammary gland tissues, cross-linked HA levels were significantly decreased in breast cancer and associated with tumor malignancy. When NFbs were activated into CAFs, the levels of cross-linked HA and TSG6 were both suppressed. Through upregulating TSG6, CAFs restored the high level of cross-linked HA and significantly inhibited breast cancer malignancy, whereas NFbs promoted the malignancy when the cross-linked HA level was reduced. Furthermore, the inhibitory role of HA cross-linking in tumor malignancy was directly verified using the synthesized HA-HC complex. Collectively, our study found that the deficiency of cross-linked HA induced breast cancer malignancy in a CAF-dependent manner, suggesting that recovering HA cross-linking may be a potential therapeutic strategy.

Interactions Between the Breast Tissue Microbiota and Host Gene Regulation in Nonpuerperal Mastitis

Background: Nonpuerperal mastitis (NPM) causes considerable psychological distress in females, since it is difficult to diagnose and treat. A spectrum of etiological factors, ranging from infection to autoimmune disorders, can lead to NPM. However, the pathogenesis of NPM remains unclear. Here, we aimed to dissect the role of host gene-microbe interactions in NPM. Methods: We performed 16S rRNA sequencing to characterize the breast tissue microbiome and identify bacteria that were differentially abundant between NPM patients and controls. We also performed 16S rRNA sequencing to characterize the gut microbiome and identify gut microbes with different abundances between NPM patients and healthy controls. Moreover, we investigated whether the breast tissue microbiome was associated with an altered gut microbiome in patients with NPM. We analyzed differentially expressed genes in inflammatory tissues of mammary gland from patients with NPM and normal mammary gland tissues from patients with benign and non-infectious breast disease by RNA-sequencing (RNA-seq). The landscape of infiltrating immune cell subtypes in the breast tissue immune microenvironment was analyzed using CIBERSORT, based on the gene expression profiling of breast tissues. Lastly, we modeled associations of relative abundances of specific bacterial taxa with differential expression of immune-related genes and differences in infiltrating immune cells. Results: The composition and functions of the breast tissue microbiota communities differed between NPM patients and controls. The breast tissue shared a relatively small proportion of bacterial communities with the gut in patients with NPM. The relative abundance of Ruminococcus (family Ruminococcaceae) of breast tissue was positively correlated with the differentially expression of immune-related genes between NPM patients and controls, including antigen processing and presentation genes (ICAM1, LGMN, THBS1, TAP1, HSPA1B and HSPA1A), cytokine receptor gene IL15RA, and chemokine gene CCN1. The relative abundances of Rhizobium of breast tissue was negatively correlated with the differentially expression of the antigen processing and presentation gene HSPA6 between NPM patients and controls. We also found that the relative abundance of Ruminococcus (family Ruminococcaceae), Coprococcus, and Clostridium of breast tissue positively correlated with the difference of CD8+ T cells between NPM patients and controls. The relative abundance of Ruminococcus (family Ruminococcaceae) of breast tissue positively correlated with resting memory CD4+ T cells. The relative abundance of Leucobacter of breast tissue negatively correlated with CD8+ T cells. The relative abundance of Caulobacter of breast tissue positively correlated with activated memory CD4+ T cells. Conclusions: Our results explored the potential role of host-microbe interactions in the etiology of NPM. We demonstrate cross-talk between the breast tissue microbiome and the gut microbiome in patients with NPM. We suggest that NPM microbiome composition influences the immune microenvironment and natural history of the disease by affecting the transcriptome, which merits further study. Funding Information: This study was supported by the Youth Science Fund Project of Jiangxi Provincial Department of Science and Technology (20192BAB215037), the Science and Technology Project of Education Department of Jiangxi Province (GJJ180057) and the Science and Technology Project of Education Department of Jiangxi Province (GJJ180056). Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: The study was approved by the Ethics Committee of the First Affiliated Hospital of Nanchang University (Nanchang, China), and informed consent was obtained from all subjects.

Canine mammary cancer tumour behaviour and patient survival time are associated with collagen fibre characteristics

Precise diagnosis and prognosis are key in prevention and reduction of morbidity and mortality in all types of cancers. Here we show that changes in the collagen fibres in the main histological subtypes of canine mammary gland carcinomas are directly associated with the tumour behaviour and the animal survival time and could become a useful tool in helping with diagnosis. Imaging by second harmonic generation and multiphoton excited fluorescence microscopy were performed to evaluate the collagen and cellular segment parameters in cancer biopsies. We present a retrospective study of 45 cases of canine mammary cancer analysing 836 biopsies regions including normal mammary gland tissue, benign mixed tumours, carcinoma in mixed tumour, carcinosarcoma, micropapillary carcinoma and solid carcinoma. The image analyses and the comparison between the tumour types allowed to assess the collagen fibre changes during tumour progression. We demonstrate that the collagen parameters correlate with the clinical and pathological data, the results show that in neoplastic tissues, the collagen fibres are more aligned and shorter as compared to the normal tissues. There is a clear association of the mean fibre length with the dogs survival times, the carcinomas presenting shorter collagen fibres indicate a worse survival rate.

Senescence Marker Protein 30 (SMP30): A Novel Pan-Species Diagnostic Marker for the Histopathological Diagnosis of Breast Cancer in Humans and Animals.

Senescence marker protein 30 (SMP30) is a cell survival factor playing an important role in vitamin C synthesis and antiapoptosis. Moreover, its cytoprotective role suggests a possibility to be related to cancer cell survival. Mammary carcinoma is a common cancer in both humans and animals. Because of its histopathological diversity, especially in the early stage, histopathological diagnosis may be complicated; therefore, a diagnostic marker is helpful for confirmation. The present study analyzed the expression pattern of SMP30 in mammary carcinoma in humans, dogs, and cats. Immunohistochemistry, immunofluorescence, and western blot analysis were used to investigate SMP30 expression patterns. The expression was specifically observed in neoplastic glandular epithelial cells. The expression increased with the malignancy of glandular epithelial cells with a highly proliferative status. However, SMP30 expression was low in normal mammary gland tissues or well-differentiated adenoma tissues. The patterns were consistently reproduced in canine primary mammary carcinoma cells and MCF-7 and MDA-MB-231 human carcinoma cell lines. This study provides useful information to understand SMP30 expression in various stages of mammary carcinoma and to suggest its utility as a pan-species diagnostic marker, thereby helping to establish strategies for diagnosing mammary carcinoma in several species.

A male with primary accessory breast carcinoma in an axilla is strongly suspected of having hereditary breast cancer

We herein report on a male with primary accessory breast cancer in an axilla. A 75-year-old man first noticed a subcutaneous nodule about 2 cm in diameter in the area of his right axilla. The patient underwent extirpation of the mass in a public hospital. Histological examination revealed invasive breast carcinoma of no special type associated with mucinous carcinoma, invasive micropapillary carcinoma and intraductal components. Immunohistochemical analysis showed that the tumor cells were positive for Gross cystic disease fluid protein (GCDFP)-15, mammaglobin and GATA3. Staining for estrogen receptor (ER) and progesterone receptor (PR) was positive, and human epidermal growth factor receptor 2 (HER2) was negative. The Ki67 labeling index (LI) was 33.6%. Imaging revealed no evidence of a primary tumor in any other organ or in the bilateral mammary gland. We performed radical resection of the right axilla, including the scar, and axillary lymph node dissection. The final pathological examination of the surgical specimen showed normal mammary gland tissue that was not connected to the proper mammary gland, and no residual cancer or metastatic lymph nodes. Based on our clinical and pathological findings, this tumor was diagnosed as breast cancer originating from the accessory mammary gland in the right axilla. After surgery, tamoxifen was administered as adjuvant therapy. Since the surgery, 2 years ago, there has been no evidence of recurrence. Hereditary Breast and Ovarian Cancer syndrome was suspected in this case because the patient was a male with breast cancer, and he had two first-degree relatives with breast cancer. This patient had no BRCA mutations on genetic testing. Nonetheless, in cases of male breast cancer, it is necessary to obtain genetic information due to the possibility of hereditary breast cancer, including cancers associated with BRCA gene mutation.

Altered prolactin and androgen receptors expression in companion rat benign mammary tumours.

Benign mammary tumours are among the most common tumours of companion rats (Rattus norvegicus domestica), as well as a major animal welfare concern and euthanasia. The first objective of this study was to evaluate the expression of oestrogen, progesterone, androgen, and prolactin receptors in neoplastic and normal mammary gland tissues and compare the expression of these receptors between groups. The second objective was to determine if the expression of these receptors in neoplastic mammary gland tissue correlates with overall survival and occurrence of an additional mass after initial mammary mass excision. The third objective was to determine if the expression of oestrogen, progesterone, androgen and prolactin receptors was associated with mammary tumor clinical parameters or with the age of the animals. Thirty-two benign mammary tumours were collected from companion rats and submitted for immunohistochemistry staining of prolactin receptor, oestrogen receptor alpha (ERa), progesterone and androgen receptors (AR). Allred score were obtained for mammary tumours (n=32) and surrounding normal mammary tissue (n=20) when present. Prolactin receptor expression increased significantly with mammary gland tumorigenesis (P < .0001), while AR expression decreased with tumorigenesis (P < .0001). Lower expression of ERa in tumor stroma was associated with shorter survival (P=.02). Hormonal receptor expression was not significantly associated with age, mass diameter, location nor likelihood of additional mass development. Further studies should investigate the effects of prolactin antagonists in a prospective study involving companion rats with benign mammary tumours.

Immunostaining of lectin glycoconjugates in primary and metastatic canine mammary neoplasms

The aim of this study was to investigate glycoconjugate immunostaining of the biotinylated lectins: UEA - Ulex europaeus (gorse), PNA - Arachis hypogaea (peanut), HPA - Helix pomatia (Roman snail), and DBA - Dolichos biflorus, in normal mammary glands (control; n = 7), mammary neoplasms (n = 111), and mammary neoplasm metastasis (n = 10). One hundred twenty-eight mammary gland tissue samples were used; 7 samples without history of neoplasms (control). The remaining samples (121) were mammary neoplasms or metastasis. In all cases (UEA, HPA, PNA, and DBA), the binding to normal epithelium was uniform. The immunohistochemical marking was in the membrane and cytoplasm of epithelial cells in most of the cases. Large variations of binding between cell membranes, cytoplasm, and nuclei occurred in the neoplastic and metastatic tissues. Though lacking statistical differences, UEA, PNA, HPA, and DBA lectins revealed different marking patterns between tissues, being metastatic foci less marked in comparison with normal and neoplastic mammary gland tissues. In addition, there were no significant differences in the immunostaining of lectins between tumors where HPA was the most expressed in papillary carcinoma I, PNA in papillary carcinoma II, DBA in carcinosarcoma, and HPA and DBA in mixed carcinoma. It was concluded that the lectins have diagnostic potential and they have been useful for differentiation between normal and neoplastic breast tissue of metastatic foci in mammary tumor in dogs.

Decorin concentrations in canine normal and neoplastic mammary gland tissues.

In the present study, the concentration of decorin in canine normal and neoplastic mammary gland tissues was examined to understand the potential role of decorin in development and progression of canine mammary tumours. The homogenates of 48 mammary gland tumours (10 benign and 38 malignant) and 10 samples of normal canine mammary gland tissue were used in the study. The presence and quantification of decorin was examined in the homogenates using Western blot and specific canine ELISA. Western blotting confirmed the presence of decorin both in the normal mammary gland tissues and in the mammary gland tumours. The concentration of decorin was significantly higher (p<.05) in the benign tumours and non-metastatic malignant tumours than in the normal mammary gland. The concentration of decorin was significantly lower (p<.05) in the malignant tumours with metastasis to regional lymph nodes compared with benign tumours and non-metastatic malignant tumours. No significant differences were found in the level of decorin between the benign and the non-metastatic malignant tumours. Both the histological type of malignant tumours and the histological grade did not significantly affect the concentration of decorin. These findings suggest that neoplastic transformation in the canine mammary gland leads to increase in the decorin protein synthesis. The reducing decorin concentration in canine malignant mammary tumours appears to facilitate the metastatic spread of these tumours.