Vitamin D status in female dogs with mammary gland tumors.

Background: Little information exists about vitamin D status in bitches with mammary tumors.

Objectives: To determine whether low plasma vitamin D concentrations are found in bitches with mammary tumors.

Animals: Eighty-five client-owned bitches with mammary tumors (n = 21 benign, n = 64 malignant) and 39 age-matched healthy bitches.

Analysis of cell-free DNA concentration, fragmentation patterns and gene expression in mammary tumor-bearing dogs: A pilot study.

Introduction: Liquid biopsy based on the analysis of circulating cell-free DNA (cfDNA), as well as on detection of point mutations by digital droplet PCR (ddPCR), has revolutionized the research in oncology. In recent years, this technique has been pioneering in veterinary medicine since it is a minimally invasive approach with very promising results for characterization of tumors.

Methods: The aim of this study was, firstly, to analyze the concentration and the fragmentation pattern of cfDNA of dogs with mammary tumors ( = 36) and healthy dogs ( = 5) and its correlation with clinicopathological data.

In vitro and in vivo effects of toceranib phosphate on canine osteosarcoma cell lines and xenograft orthotopic models.

Canine osteosarcoma (OSA) is the most common primary malignant bone tumour in dogs, and it has a high metastatic rate and poor prognosis. Toceranib phosphate (TOC; Palladia, Zoetis) is a veterinary tyrosine kinase inhibitor that selectively inhibits VEGFR-2, PDGFRs and c-Kit, but its efficacy is not yet fully understood in the treatment of canine OSA. Here, we evaluated the functional effects of TOC on six OSA cell lines by transwell, wound healing and colony formation assays.

Immunohistochemical expression of p63 protein and calponin in canine mammary tumours.

The aim of this study was to compare the expression of p63 protein and calponin in terms of their affinity and specificity for myoepithelial cells in canine mammary tumours. The studied material included 10 benign and 32 malignant mammary tumours from female dogs treated with mastectomy. Primary mouse monoclonal antibodies directed against p63 protein clone 4A4 and calponin clone CALP were used in single- and doublestain system of immunohistochemical reaction.

Immunohistochemical and quantitative RT-PCR methods to assess RANK expression in normal and neoplastic canine mammary gland.

The receptor activator of nuclear factor-kB ( RANK) gene is found in both human and murine mammary epithelial cells and in human cancer cell lines. We analyzed RANK expression in normal and proliferative canine mammary tissue samples ( n = 47) and cell lines ( n = 10), and identified its expression in epithelial cell populations. The correlation of RANK protein with clinicopathologic parameters was also studied.

Myoepithelial cells in canine mammary tumours.

Mammary tumours are the most common neoplasms of female dogs. Compared to mammary tumours of humans and cats, myoepithelial (ME) cell involvement is common in canine mammary tumours (CMT) of any subtype. Since ME cell involvement in CMT influences both histogenetic tumour classification and prognosis, correct identification of ME cells is important.

Progesterone receptor isoform A may regulate the effects of neoadjuvant aglepristone in canine mammary carcinoma.

Background: Progesterone receptors play a key role in the development of canine mammary tumours, and recent research has focussed on their possible value as therapeutic targets using antiprogestins. Cloning and sequencing of the progesterone receptor gene has shown that the receptor has two isoforms, A and B, transcribed from a single gene. Experimental studies in human breast cancer suggest that the differential expression of progesterone receptor isoforms has implications for hormone therapy responsiveness.

Increased expression of insulin-like growth factor-1 receptor is correlated with worse survival in canine appendicular osteosarcoma.

Insulin-like growth factor 1 receptor (IGF-1R) is a cell membrane receptor widely expressed in tissues and involved in different cancers in humans. IGF-1R expression in human osteosarcoma has been associated with the development of tumour metastasis and with prognosis, and represents an attractive therapeutic target. The goal of this study was to investigate the expression of IGF-1R in canine osteosarcoma tissues and cell lines and assess its role and prognostic value.

The antiprogestins mifepristone and onapristone reduce cell proliferation in the canine mammary carcinoma cell line CMT-U27.

Canine mammary tumours (CMTs) represent nearly half of all tumours in female dogs and some 50% have malignant behaviour. Simple epithelial carcinomas have shorter disease free periods after surgery and a higher reduction of the proliferation index reduction after antiprogestin aglepristone treatment in vivo related to the expression of progesterone receptors (PR). These findings make simple carcinomas good candidates for endocrine therapy.

Activation of mammalian target of rapamycin (mTOR) in triple negative feline mammary carcinomas.

Background: Triple negative breast cancer (TNBC) in humans is defined by the absence of oestrogen receptor (ER), progesterone receptor (PR) and HER2 overexpression. Mammalian target of rapamycin (mTOR) is overexpressed in TNBC and it represents a potential target for the treatment of this aggressive tumour. Feline mammary carcinoma (FMC) is considered to be a model for hormone-independent human breast cancer.

Liver stiffness using transient elastography is applicable to canines for hepatic disease models.

Background: The objectives of this study were to evaluate the best position and best exploration probe for determining liver stiffness (LS) in dogs using transient liver elastography (TE). Thirteen dogs were used in the study.

Methodology/principal Findings: Morphometric measurements taken were thoracic circumference, weight and height.

Immunoneutralization of inhibin in cycling rats increases follicle-stimulating hormone secretion, stimulates the ovary and attenuates progesterone receptor-dependent preovulatory luteinizing hormone secretion.

Passive immunization against inhibin with an anti-inhibin serum (AIS) during the diestrous phase in cycling rats increased follicle-stimulating hormone secretion, stimulated the ovaries and reduced the magnitude of the luteinizing hormone (LH) surge in the afternoon of proestrus. The involvement of gonadotrope progesterone receptor (PR) expression/action in the inhibitory effects of the follicle-stimulating hormone-dependent putative ovarian factor gonadotropin surge-attenuating factor on preovulatory LH secretion was studied in the absence of circulating free inhibin. Proestrous pituitaries from rats injected with AIS or a non-immune serum (NIS) were studied for determination of PR-AB and PR-B mRNAs by RT-PCR and PR-B and PR-A isoform proteins by Western blot.

Activation of estrogen receptor-alpha induces gonadotroph progesterone receptor expression and action differently in young and middle-aged ovariectomized rats.

Background: We attempted to define the effect of estrogen receptor (ER)alpha activation on gonadotroph progesterone receptor (PR) expression (mRNA and protein) and action (GnRH-stimulated and GnRH self-priming) in short- and long-term ovariectomized (OVX) rats.

Methods: Two weeks or 1 year after OVX, rats were injected over 3 days with 125 microg/kg of estradiol benzoate (EB), 7.5 mg/kg of the selective ERalpha agonist propylpyrazole triol (PPT), or 15 mg/kg of the selective ER modulator tamoxifen (TX).