Feline Mammary Gland Research Articles

The expression of sialyl Lewis X in canine and feline mammary gland tumors.

The expression of sialyl Lewis X (sLe(x)) in 93 canine and 15 feline mammary gland tumors (MGT) obtained by surgical resection at Veterinary Medical Center, the University of Tokyo was examined by immunohistochemistry. Their clinicopathological features and prognosis were also reviewed. Approximately 60% of MGT tissues showed sLe(x) positive expressions, while all normal mammary gland tissues were negative. However, its expression was not correlated with clinicopathological features and prognosis significantly. This study suggests that sLe(x) may be a tumor-associated antigen in canine and feline MGTs.

Animal models of human breast carcinoma: canine and feline neoplasms

Domestic animals develop spontaneously many of the diseases that also affect human beings, including cancer, and thus are excelent natural models of those diseases. The canine and feline mammary gland carcinoma is one of the natural models proposed by the World Health Organization because of its epidemiologic, clinical and morphologic similarities with human breast cancer. Incidence is high in both domestic species, which allows to perform statistically significant studies in short periods of time and risk factors are similar (including hormone-dependence). Biological behaviour of canine mammary gland tumors is malignant in some 50% of the cases, while more than 90% of feline tumors are malignant and characterized by rapid growth, invasion, ulceration and metastases. Although classification schemes of human, canine and feline mammary gland carcinomas are different, the histologic picture is qu!te similar, as well as prognostic factors (tumour size, lymph node metastases, and histological and nuclear degree, among others).

Oestrogen and progesterone receptors in feline fibroadenomatous change: an immunohistochemical study

The distribution of oestrogen and progesterone receptors was analysed in 18 cases of feline fibroadenomatous change (FFAC) using commercially available specific monoclonal antibodies and the Avidin–biotin peroxidase complex technique on formalin-fixed, paraffin-embedded tissue. In all cases of FFAC, progesterone receptors were detected either in epithelial cells (mostly suprabasal) or in epithelial and stromal cells. Oestrogen receptors were detected in approximately half of these cases, in suprabasal or luminal epithelial cells exclusively. Myoepithelial cells lacked both oestrogen and progesterone receptors. The techniques used have identified the specific cellular distribution of steroid hormones receptors in this hormone-dependent lesion of the feline mammary gland. The results confirm those of previous biochemical analyses with respect to progesterone receptors and add new data concerning the possible involvement of oestrogen receptors and stromal fibroblasts in the hormonal control and development of the lesion.

Coordinate expression of cytokeratins 7 and 20 in feline and canine carcinomas.

Forty-seven feline and 60 canine epithelial tumors were studied to test the coordinate expression of cytokeratin 7 (CK 7) and cytokeratin 20 (CK 20) using commercially available monoclonal antibodies and an avidin-biotin immunoperoxidase staining technique. Previously, the distribution of both cytokeratins was examined in normal tissues from 4 cats and 4 dogs. The pattern of distribution of CK 7 in normal tissues was similar, with minor differences, to that described in humans, whereas the reactivity pattern of CK 20 in cats and dogs was wider than that in humans. The subset of tumors strongly expressing CK 7 and CK 20 included pancreatic adenocarcinomas (100%), transitional cell carcinomas (75%), and endometrial carcinomas (67%) in the cat. None of the canine tumors had this immunophenotype. Feline (50%) and canine (56%) mammary gland carcinomas and canine cholangiocarcinomas (67%) were the only tumors presenting the CK 7 +/CK 20- immunophenotype, whereas the CK 7-/CK 20+ immunophenotype included thyroid carcinomas (100%), intestinal adenocarcinomas (60%), bronchioloalveolar carcinomas (50%), and renal carcinomas (50%) in the cat and intestinal adenocarcinomas (56%), gastric adenocarcinomas (50%), and ovarian carcinomas (50%) in the dog. The CK 7-/CK 20- immunophenotype included the rest of the analyzed tumors. The immunohistochemical evaluation of coordinate expression of both CK 7 and CK 20 in feline and canine carcinomas using monoclonal antibodies provides important information that can help to discriminate among carcinomas from different primary sites and could be particularly helpful in the determination of the primary site of origin of carcinomas presenting as metastatic disease.

Immunohistochemical distribution pattern of intermediate filament proteins and muscle actin in feline and human mammary carcinomas

Thirty-seven feline and 38 human spontaneous mammary gland carcinomas were studied immunohistochemically. Commercially available antibodies directed against high and low molecular weight keratins (RCK-102 and NCL-5D3), vimentin, desmin, glial fibrillary acidic protein (GFAP), neurofilament (NF) proteins and muscle actin (HHF35) were used in the avidin biotin peroxidase complex (ABC) technique on formalin-fixed paraffin wax-embedded tumour tissue samples. Healthy feline and human mammary gland tissue adjacent to the neoplasms was also examined. The distribution pattern of intermediate filament proteins and muscle actin was comparable in healthy mammary gland tissue of the two species: both RCK-102 and NCL-5D3 antibodies reacted with luminal epithelial cells of ducts and acini, but basal/myoepithelial cells were stained by RCK-102 exclusively. In addition, basal/myoepithelial cells expressed vimentin and muscle actin in both species, and GFAP was found in some feline basal/myoepithelial cells. No immunoreactivity to desmin and NF proteins was observed. Feline mammary gland carcinoma cells reacted with RCK-102 (89%), NCL-5D3 (62%), vimentin (76%) and GFAP (30%) antibodies, while human mammary gland carcinoma cells reacted with RCK-102 (95%), NCL-5D3 (100%) and vimentin (13%) antibodies. HHF35 immunoreactivity was observed in stromal cells only. These results indicate that mammary gland carcinomas of both species share a heterogeneous immunophenotype with respect to intermediate filament proteins, which adds to the list of known similarities between mammary gland carcinomas of both species.

Modulation of mammary carcinoma cell phenotype and keratin expression patterns by retinoic acid

Immunohistochemical and biochemical procedures were used to study the influence of retinoic acid (RA) on cellular expression and distribution of cytokeratins (CKs) in feline mammary carcinoma cells. These cells were grown in vitro as established cell lines (K248C and K266) and in vivo as xenografts in athymic mice. The results were compared with the distribution of CKs in normal feline mammary gland and in a series of invasive mammary carcinomas previously probed with a panel of monoclonal antibodies specific for individual CKs. Coexpression of CKs of both major mammary gland cell types (myoepithelial cells, MECs, CKs 5 14 positive, and luminal epithelial cells, LECs, CKs8 18 positive) by K248C and K266 cells, suggested a stem cell-like character of both cell lines. RA increased CK 19 expression in both cell lines and CK 19 was also present in tumors developed in nude mice from both RA untreated (CK 19 negative) and RA-treated (CK 19 positive) K248C and K266 cells. In addition, RA had cell line specific effects as well. RA treatment induced differentiation of K248C cells to more mature LEC-like cells and this change was accompanied by the loss of the MEC keratins CKs 5 14 . Under the same culture conditions however, RA treatment did not induce morphological changes in the K266 cell line and the expression of CKs 5 14 was not significantly reduced. These findings suggest that the modulation of CK 19 and CKs 5 14 expression observed in mammary carcinoma cells upon RA treatment might be regulated through different pathways.

Feline mammary hypertrophy.

A retrospective study of some 500 biopsies from female cats showed 12 ex­ amples of a benign fibroglandular proliferation of the mammary gland. This condition has not been reported in the literature. The lesion resembles pericanalicular fibroadenoma of women and may involve one or more mammary glands in young, intact queens. No statistically significant breed incidence was found. The growths regress with ovariectomy, which suggests hormonal pathogenesis (hyperprogesteronism). A retrospective study of some 500 biopsies from cats at the University of Pennsylvania School of Veterinary Medicine showed 12 examples of a benign fibroglandular proliferation of the mammary gland. The many reports in the literature concerning neoplasms of the feline mammary gland have paid little attention to the benign growths and have dealt mainly with the more common malignant tumors. I n his discussion of feline neoplasia, COTCHIN (6) merely stated that mam­ mary adenomas were rare. NIELSEN (14) reported only one benign tumor out of 21 cases. I n a later report (15), he did not mention benign tumors. ) n their survey of feline neoplasia, SCHMIDT and LANGHAM (18) mentioned six adeno­ mas out of a total of 30 mammary tumors, but they did not discuss the histo­ logic appearance of these lesions. Seven adenofibromas and one adenoma were included in WHITEHEAD'S series (21), but no incidence or histologic data were provided. BRODEY (5) gave the incidence of benign tumors as 20% in the cat. In their report of cat tumors, HAYDEN and NIELSEN (II) recorded two fibroadenomas among five benign tumors and provided a detailed de­ scription of the histornorphology of these growths. Admittedly, the condition described in the present report is likewise uncommon, but it has not been previously reported.