RESUMO
BACKGROUND: Osteosarcoma is a malignant mesenchymal bone tumor. Although it is a common tumor in the appendicular skeleton of dogs and cats, it is rarely reported in birds. Retroviruses are usually associated with solid tumor development in different avian species. CASE PRESENTATION: This report aims to describe a case of osteosarcoma associated with the avian leukosis virus in a captive bare-faced curassow (Crax fasciolata). A captive adult female bare-faced curassow presented with lameness, hyporexia, and a non-ulcerative and firm tumor in the right femur. The bird was euthanized due to the poor prognosis. Histopathology revealed an infiltrative mesenchymal neoplasm consisting of spindle cells with moderate cell pleomorphism, organized in bundles and interspersed by marked deposition of the osteoid matrix, which was compatible with osteosarcoma affecting both femur and tibiotarsus, with renal metastasis. Immunohistochemistry of the primary and metastatic tumor demonstrated vimentin expression by neoplastic cells. Samples of the neoplasm, bone marrow, and spleen were processed for PCR, which enabled the demonstration of proviral avian leukosis virus (ALV) DNA. CONCLUSIONS: To the best of our knowledge, this is the first report of an osteosarcoma in a bare-faced curassow with an unusual polyostotic manifestation and associated with ALV infection.
Assuntos
Leucose Aviária , Doenças das Aves/patologia , Neoplasias Ósseas/veterinária , Osteossarcoma/veterinária , Animais , Vírus da Leucose Aviária/isolamento & purificação , Doenças das Aves/virologia , Medula Óssea/virologia , Neoplasias Ósseas/virologia , Feminino , Galliformes/virologia , Neoplasias Renais/secundário , Neoplasias Renais/veterinária , Osteossarcoma/virologia , Baço/virologia , Vimentina/metabolismoRESUMO
E7 is the major transforming activity in human papillomaviruses, a causal agent for cervical cancer. HPV16 E7 is a small protein with a natively unfolded domain for which dozens of specific cellular targets were described, and represents a prototypical oncoprotein among small DNA tumor viruses. The protein can form spherical oligomers with amyloid-like properties and chaperone activity. Conformation specific antibodies locate endogenous oligomeric E7 species in the cytosol of 3 model cell lines, strongly co-localizing with amyloid structures and dimeric E7 localizes to the nucleus. The cytosolic oligomeric E7 appear as the most abundant species in all cell systems tested. We show that nuclear E7 levels are replenished dynamically from the cytosolic pool and do not result from protein synthesis. Our results suggest that long-term events related to de-repression of E7 would cause accumulation of excess E7 into oligomeric species in the cytosol. These, together with the known target promiscuity of E7, may allow interactions with many of the non-pRb dependent targets described. This hypothesis is further supported by the detection of E7 oligomers in the cytosol of cancerous cells from tissue biopsies.
Assuntos
Amiloide/química , Carcinoma Endometrioide/metabolismo , Transformação Celular Neoplásica , Citosol/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Osteossarcoma/metabolismo , Neoplasias do Colo do Útero/metabolismo , Animais , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Neoplasias Ósseas/virologia , Carcinoma Endometrioide/patologia , Carcinoma Endometrioide/virologia , Núcleo Celular/metabolismo , Feminino , Imunofluorescência , Humanos , Immunoblotting , Técnicas Imunoenzimáticas , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Oncogênicas Virais/genética , Osteossarcoma/patologia , Osteossarcoma/virologia , Papillomaviridae , Proteínas E7 de Papillomavirus , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Transfecção , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologiaRESUMO
Burkitt's lymphoma may involve the maxilla or mandible, but to date, there has been no reference in the literature to scapular involvement by this tumor. This article describes the case of a 9-year-old child who presented with a huge tumor involving the right shoulder with osteolytic and sclerotic lesions in the scapula. The histopathological findings were suggestive of Burkitt's lymphoma, and the immunohistochemical findings discard a lymphoblastic lymphoma or plasmablastic lymphoma. In addition, in situ hybridization for Epstein-Barr virus encoded small nuclear RNA (EBER) was positive. Although the child also presented a cervical lymphadenopathy, the fact that Burkitt's lymphoma is generally extranodal, the marked swelling of the shoulder, and the extensive involvement of the bone strongly argue that this tumor had its origin in the scapula. This case demonstrates the importance of including Burkitt's lymphoma in the differential diagnosis of lymphoma involving bones in children.