Expression of the Short Form of RON/STK in Feline Mammary Carcinoma.

RON is a tyrosine kinase receptor activated by the macrophage-stimulating protein (MSP) ligand that is overexpressed in human breast cancer. In humans, RON protein can be present in different isoforms, and the most studied isoform is represented by the short form of RON ( sf-RON), which is generated by an alternative promoter located in intron 10 of the RON complementary DNA (cDNA). It plays an important role in breast cancer progression.

Uncommon acute neurologic presentation of canine distemper in 4 adult dogs.

Four uncommon cases of canine distemper (CD) were diagnosed in vaccinated adult dogs. All dogs had acute onset of neurologic signs, including seizures, abnormal mentation, ataxia, and proprioceptive deficits. Polymerase chain reaction for CD virus was positive on cerebrospinal fluid in 2 cases.

Progesterone receptor isoform analysis by quantitative real-time polymerase chain reaction in formalin-fixed, paraffin-embedded canine mammary dysplasias and tumors.

Cloning and sequencing of the progesterone receptor gene in dogs have revealed 2 isoforms, A and B, transcribed from a single gene. Distribution of isoforms A and B in canine mammary lesions has hitherto been investigated only by Western blot analysis. This study analyzed progesterone receptor and its isoforms in formalin-fixed, paraffin-embedded tissue samples from canine mammary lesions (4 dysplasias, 10 benign tumors, and 46 carcinomas) using 1-step SYBR Green quantitative real-time polymerase chain reaction (RT-qPCR).

Canine mammary tumors: a review and consensus of standard guidelines on epithelial and myoepithelial phenotype markers, HER2, and hormone receptor assessment using immunohistochemistry.

Although there have been several studies on the use of immunohistochemical biomarkers of canine mammary tumors (CMTs), the results are difficult to compare. This article provides guidelines on the most useful immunohistochemical markers to standardize their use and understand how outcomes are measured, thus ensuring reproducibility of results. We have reviewed the biomarkers of canine mammary epithelial and myoepithelial cells and identified those biomarkers that are most useful and those biomarkers for invasion and lymph node micrometastatic disease.

Primary central nervous system T-cell lymphoma mimicking meningoencephalomyelitis in a cat.

A cat was presented with right head tilt and circling. The lack of expression of virus antigens did not support the postmortem diagnosis of encephalomyelitis pointing to a diffuse primary central nervous system T-cell lymphoma on the basis of CD3 and CD45R co-expression with absence of CD79α staining.

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.

Malignant mesenchymoma of the heart base in a dog with infiltration of the pericardium and metastasis to the lung.

A 9-year-old male rottweiler was presented with abdominal distension, ascites and respiratory distress and marked bulging in the perineal region. At necropsy examination the animal had profuse ascites and hydropericardium and a multinodular mass in the right auricle of the heart infiltrating the epicardium and pericardium and metastasizing to the caudal lobe of the left lung. Microscopically and immunohistochemically the tumour was composed of neoplastic cells with muscular, cartilaginous and adipose differentiation.

Estrogen receptor (ESR) 2 partially offsets the absence of ESR1 in gonadotropes of pituitary-specific Esr1 knockout female mice.

Estrogen receptor 1 and 2 (ESR1 and 2) mediate estrogen (E) action on gonadotrope function. While much is known about the effects of ESR1 on the gonadotrope, there is still some controversy regarding the effects of ESR2. To investigate the role of ESR2 in the gonadotrope, 45-day-old female mice of two different genotypes were used: wild type (WT) and pituitary (gonadotropes and thyrotropes)-specific Esr1 knockout (KO).

Activation of AKT in feline mammary carcinoma: a new prognostic factor for feline mammary tumours.

The PI3K/AKT/PTEN pathway is involved in the pathogenesis of several human cancers. This study investigated the biological and prognostic value of PI3K/AKT/PTEN pathway dysregulation in feline mammary tumours. Expression of p-AKT, HER2, PTEN and steroid receptors was assessed by immunohistochemistry (IHC) in 27 malignant and 12 benign mammary tumours from 39 female cats followed up over a 24-month period.

Oligodendroglial gliomatosis cerebri in a poodle.

Gliomatosis cerebri (GC) is a rare, diffusely infiltrating, glial cell tumour of neuroepithelial origin. This report describes a case of oligodendroglial GC in a 6-year-old male Poodle with central nervous system symptoms. Computed tomography revealed anomalous parenchyma density and ventricular asymmetry.

Human follicular fluid from superovulated women inhibits progesterone receptor-dependent gonadotropin-releasing hormone self-priming in an estrous cycle-dependent manner in the rat.

These experiments investigated the involvement of gonadotrope progesterone receptor (PR) in the effects of the putative gonadotropin surge-attenuating factor (GnSAF) on gonadotropin (LH and FSH) secretion. Human follicular fluids (hFF) used in this study were aspirated from follicles in gonadotropin-treated women for in vitro fertilization. Samples were subjected to two-fold charcoal extraction of steroid hormones and two-fold inhibin immunoprecipitation.

Expression of oestrogen and progesterone receptors in canine sebaceous gland tumours.

Sebaceous gland oestrogen alpha (ERalpha) and progesterone (PR) receptor expression was examined immunohistochemically in 26 and 32 dogs respectively with sebaceous gland hyperplasia/adenomas, epitheliomas and carcinomas, and in the glands of 10 healthy controls. The mean percentage of ERalpha positive nuclei in control sebaceous glands was 21.31% compared with 11.

Immunohistochemical localisation of 14-3-3 sigma protein in normal canine tissues.

The 14-3-3 sigma protein, also called stratifin, belongs to the highly conserved family of 14-3-3 acid proteins, which are involved in the modulation of diverse signal transduction pathways. Loss of 14-3-3 sigma expression has been observed in several types of human cancers, suggesting that it may have a role as a tumour suppressor gene. The 14-3-3 sigma protein has been localised in normal human tissues exclusively in various epithelial cell types.

Ovarian stimulation with FSH reduces phosphorylation of gonadotrope progesterone receptor and LH secretion in the rat.

Administration of human FSH (hFSH) to cyclic rats during the dioestrous phase attenuates progesterone receptor (PR)-dependent events of the preovulatory LH surge in pro-oestrus. The increased bioactivity of the putative ovarian gonadotropin surge inhibiting/attenuating factor induced by hFSH treatment is not associated with a decrease in PR protein expression, and the possibility of its association at a PR posttranslational effect has been raised. The present experiments aimed to analyse PR phosphorylation status in the gonadotrope of rats with impaired LH secretion induced by in vivo hFSH injection.

Molecular characterization and expression analysis of the gene coding for the porcine beta(3) integrin subunit (CD61).

Integrins are heterodimeric cell adhesion molecules with major roles in a variety of biological processes ranging from cell migration to tissue organization, immune and non-immune defense mechanisms and oncogenic transformation. Members of the beta(3) integrin subfamily are composed of a beta(3) subunit (CD61) non-covalently associated with two alpha subunits, alpha(IIb) (CD41) and alpha(v) (CD51), to constitute a group of transmembrane glycoproteins that participate in many physiologically important events. This investigation has focused on the molecular characterization of the cDNA encoding the porcine beta(3) integrin subunit.

Proto-oncogene HER-2 in normal, dysplastic and tumorous feline mammary glands: an immunohistochemical and chromogenic in situ hybridization study.

Background: Feline mammary carcinoma has been proposed as a natural model of highly aggressive, hormone-independent human breast cancer. To further explore the utility of the model by adding new similarities between the two diseases, we have analyzed the oncogene HER-2 status at both the protein and the gene levels.

Methods: Formalin-fixed, paraffin-embedded tissue samples from 30 invasive carcinomas, 7 benign lesions and two normal mammary glands were analyzed.

Effects of aglepristone, a progesterone receptor antagonist, in a dog with a vaginal fibroma.

A 12-year-old, entire, nulliparous crossbreed female dog was presented with a history of vulval bleeding, bulging of the perineum and faecal tenesmus. A firm, non-painful perineal mass, measuring 9.11x5.

The integrated action of oestrogen receptor isoforms and sites with progesterone receptor in the gonadotrope modulates LH secretion: evidence from tamoxifen-treated ovariectomized rats.

The specific role of each oestrogen receptor (ER) isoform (alpha and beta ) and site (nucleus and plasma membrane) in LH release was determined in ovariectomized (OVX) rats injected over 6 days (days 15-20 after OVX) with a saturating dose (3 mg/day) of tamoxifen (TX), a selective ER modulator with nuclear ERalpha agonist actions in the absence of oestrogen. This pharmacological effect of TX was demonstrated by the fact that it was blocked by the selective ERalpha antagonist methyl-piperidinopyrazole. Over the past 3 days of the 6-day TX treatment, rats received either 25 microg/day oestradiol benzoate (EB), 1.

Steroid receptors in canine and human female genital tract tumours with smooth muscle differentiation.

The expression of oestrogen receptor-alpha (ERalpha) and progesterone receptor (PR) was examined in 32 canine genital tract tumours diagnosed as smooth muscle tumours (benign or malignant, pure or mixed). The immunohistochemical expression of calponin was used to assess the smooth muscle differentiation of the tumours. Nineteen human uterine leiomyomas were also examined.

Intestinal glandular inclusions (glandular choristoma) in the mesenteric lymph node of a goat.

A glandular choristoma found in the mesenteric lymph node of a goat would appear to represent the first reported case of non-neoplastic glandular inclusions in domestic animals. The origin of this type of lesion may be difficult to determine, but in the present case cytokeratin expression patterns suggested that the inclusions had an intestinal origin.

Oestradiol-17beta inhibits tamoxifen-induced LHRH self-priming blocking hormone-dependent and ligand-independent activation of the gonadotrope progesterone receptor in the rat.

In the rat, administration of tamoxifen (TX) in the absence of oestrogen (E) induces LHRH self-priming, the progesterone receptor (PR)-dependent property of LHRH that increases gonadotrope responsiveness to itself. The oestrogen-dependent PR can be phosphorylated/activated by progesterone (P4) and, in the absence of the cognate ligand, by intracellular LHRH signals, particularly cAMP/protein kinase A. We have recently found that oestradiol-17beta (E2), acting on a putative membrane estrogen receptor-alpha in the gonadotrope, inhibits this agonist action of TX.

Gonadotropin-secreting cells in ovariectomized rats treated with different oestrogen receptor ligands: a modulatory role for ERbeta in the gonadotrope?

In the rat, oestrogen is a key regulator of gonadotrophin synthesis and release through activation of oestrogen receptors (ERs). Gonadotropes express alpha and beta isoforms of ER and both can activate transcription in response to oestrogen. These experiments were aimed at evaluating the relative contribution of ERalpha and ERbeta on gonadotrope morphology, progesterone receptor (PR) expression and LH secretion.

A prospective analysis of immunohistochemically determined estrogen receptor alpha and progesterone receptor expression and host and tumor factors as predictors of disease-free period in mammary tumors of the dog.

The immunohistochemically determined estrogen receptor (ER) alpha (ERalpha) and progesterone receptor (PR) status, as well as recognized, well-accepted prognostic indicators and host factors were prospectively analyzed in 84 cases of primary canine mammary carcinoma for their effect on disease-free period (recurrence free, metastasis free, or combined) (DFP) after an observation period of 18 months. The presence of one or both receptors, as well as tumor size, lymph node status, histologic grading, intravascular growth, and necrosis, were of prognostic value for DFP. In multivariate analysis, only tumor size and histologic grading proved to be independent prognosticators.

Localization of porcine CD29 transcripts and protein in pig cells and tissues by RT-PCR and immunohistochemistry.

Integrins are heterodimeric cell adhesion proteins with major roles in a variety of biological processes ranging from cell migration to tissue organization, immune and non-immune defense mechanisms and oncogenic transformation. Members of the beta(1) integrin subfamily are composed of a beta(1) subunit (CD29) non-covalently associated with different alpha subunits to constitute a group of transmembrane glycoproteins that participate in many physiologically important events. Here, we have studied the CD29 expression in porcine tissues and cells at two different levels: expression of the CD29 mRNA by RT-PCR and localization of the protein by immunohistochemistry.