Cell proliferation and expression of connexins differ in melanotic and amelanotic canine oral melanomas

Autor(es)

Teixeira, Tarso Felipe ^[1] ; Gentile, Luciana Boffoni ^[1] ; da Silva, Tereza Cristina ^[1] ; Mennecier, Gregory ^[1] ; Chaible, Lucas Martins ^[1] ; Cogliati, Bruno ^[1] ; Leon Roman, Marco Antonio ^[2] ; Gioso, Marco Antonio ^[2] ; Zaidan Dagli, Maria Lucia ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Pathol, Lab Expt & Comparat Oncol, BR-05508900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Surg, Lab Comparat Dent, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: VETERINARY RESEARCH COMMUNICATIONS; v. 38, n. 1, p. 29-38, MAR 2014.
• Citações Web of Science: 4

Resumo

Melanoma is a malignant neoplasm occurring in several animal species, and is the most frequently found tumor in the oral cavity in dogs. Melanomas are classified into two types: melanotic and amelanotic. Prior research suggests that human amelanotic melanomas are more aggressive than their melanotic counterparts. This study evaluates the behavior of canine melanotic and amelanotic oral cavity melanomas and quantifies cell proliferation and the expression of connexins. Twenty-five melanomas (16 melanotic and 9 amelanotic) were collected from dogs during clinical procedures at the Veterinary Hospital of the School of Veterinary Medicine and Animal Science of the University of So Paulo, Brazil. After diagnosis, dogs were followed until death or euthanasia. Histopathology confirmed the gross melanotic or amelanotic characteristics and tumors were classified according to the WHO. HMB45 or Melan A immunostainings were performed to confirm the diagnosis of amelanotic melanomas. Cell proliferation was quantified both by counting mitotic figures and PCNA positive nuclei. Expressions of connexins 26 and 43 were evaluated by immunohistochemistry, qRT-PCR and Western blot. Dogs bearing amelanotic melanomas presented a shorter lifespan in comparison to those with melanotic melanomas. Cell proliferation was significantly higher in amelanotic melanomas. Expressions of Connexins 26 and 43 were significantly reduced in amelanotic melanomas. The results presented here suggest that oral cavity melanotic and amelanotic melanomas differ regarding their behavior, cell proliferation and connexin expression in dogs, indicating a higher aggressiveness of amelanotic variants. (AU)

• Processo FAPESP: 07/56064-6 - Quantificacao da expressao das conexinas 26, 32, 43, caderina-e e da metaloproteinase 2(mmp2) em melanomas da especie canina.
• Beneficiário: Maria Lucia Zaidan Dagli
• Modalidade de apoio: Auxílio à Pesquisa - Regular