Immunohistochemical Detection of Retinoid Receptors in Tumors from 30 Dogs Diagnosed with Cutaneous Lymphoma

Abstract

Background: Retinoids exert their effects by binding to retinoid receptors. Two types of retinoid receptors have been described: retinoic acid receptor (RAR) and retinoid X receptor (RXR), and their subtypes a, b, and g. The expression of subtypes varies depending on the disease process. This study intended to detect the pattern of retinoid receptor expression in cutaneous lymphomas in dogs.Hypothesis: Cutaneous lymphomas in dogs have variable expression of retinoid and retinoid X receptors. Animals: Biopsy specimens from 30 dogs with cutaneous lymphoma. Methods: Tissues of dogs with cutaneous lymphoma were evaluated by immunohistochemistry for expression of retinoid receptors. The tissues were tested for the presence of 3 RAR and RXR subtypes (a, b, and g). Lymphoma immunophenotype was determined by the use of the immunohistochemical markers CD79a (B-cell) and CD3 (T-cell) in all cases.Results: Twenty-nine of 30 dogs were CD3 positive. The retinoid receptors expressed with the greatest frequency were RARb (87% of cases), and RXRa and RXRg (77% of cases). The expression of RARg was not observed.Conclusions and Clinical Relevance: Retinoid and rexinoid receptor binding drugs may have an impact on the treatment of dogs with cutaneous lymphoma.

Proliferation, angiogenesis and differentiation related markers in compact and follicular-compact thyroid carcinomas in dogs

“…The expression of RARα and RXR in healthy thyroid glands and thyroid carcinomas in dogs has not been reported previously. In humans, the expression of these retinoic receptors in healthy thyroid tissue, thyroid cell lines, and in thyroid adenomas and carcinomas has been reported (Hoftijzer et al, 2009); however, the expression of these receptors in dogs has only been described in lymphoma, melanoma and osteosarcoma Ohashi et al, 2006;de Mello Souza et al, 2010. In the present study, RARα expression in follicular cells did not differ in carcinomas and healthy thyroid glands.…”

“…The action of retinoic acid is mediated by retinoic acid receptors (RARs) and the retinoid X receptors (RXRs) (Kasimanickam et al, 2013). Both receptors are expressed in cutaneous lymphoma in dogs (de Mello Souza et al, 2010); however, their expression in the thyroid gland has not been described to date. Based on evidence showing that primary tumours are composed of a multitude of stromal cell types in addition to cancerous cells (Tlsty and Coussens, 2006), we investigated different markers (VEGF, FGF-2, IGF-1, IGF-1R, RARα and RXR) in compact and follicular-compact canine thyroid carcinomas.…”

A retrospective study of flow cytometric characterization of suspected extranodal lymphomas in dogs

“…9 Cutaneous lymphomas are more frequently composed of CD4– T cells with variable expression of CD8, 4,24 whereas cutaneous B-cell lymphomas are less common. 7,8…”

Post-surgical treatment of thyroid carcinoma in dogs with retinoic acid 9 cis improves patient outcome

“…In tumour cells culture lines and human TC, retinoic acid acts as anti-proliferative and redifferentiation agent of this disease (Coelho et al, 2005;Coelho et al, 2011;Oh et al, 2011;Trojanowicz et al, 2009). Although there has been investigated in vitro models for different tumours in dogs (de Mello Souza et al, 2010;Miyajima et al, 2006;Ohashi et al, 2006), there is only one report of using RA9-cis to treat Cushing's disease in dogs (Castillo et al, 2006). Our results clearly show that tumour recurrence is lower and survival time is longer in dogs treated with RA9-cis after surgery compared with dogs that were treated with doxorubicin.…”