Analysis of intraocular and pulmonary metastasis in female dogs suffering from mammary carcinoma and correlation with E-cadherin mutation and expression

Author(s)

Luciana Moura Campos Pardini

• Document type: Master's Dissertation
• Press: Botucatu. 2016-05-17.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu
• Defense date: 2015-06-03
• Advisor: José Joaquim Titton Ranzani; Adriana Camargo Ferrasi

Abstract

Introduction: E-cadherin is a transmembrane protein, encoded by CDH1 gene, that has an important role in intercellular adhesion of epithelial tissues. Loss of function or decreased expression of E-cadherin may lead to cancer progression and metastasis. In mammary epithelial neoplasms, lung metastases occur more frequently, but the ocular metastasis, especially in the choroid, are relatively common but underdiagnosed clinically. Methods: Twenty-eight dogs of different breeds, non-castrated, older than five years, diagnosed with breast cancer by cytopathological examination, without pulmonary and/or ocular metastasis, have undergone to radical mastectomy and ovariosalpingohisterectomy (OSH), and re-evaluated after three and six months postoperatively. The pattern of relative expression of CDH1 gene in normal and tumor tissues was assessed by TaqMan Universal PCR Master Mix system; the pattern of methylation was performed using MSP-PCR; DNA sequencing analysis of mutations and polymorphisms were performed from peripheral blood using the termination chain reaction technique with BigDye Terminator v.3 Cycle Sequencing kit. Immunohistochemical analyzes were performed to evaluate the expression of E-cadherin. Results: None of the 28 dogs studied had ocular or pulmonary metastasis with 3 or 6 months postoperatively. In 57,1% of cases a decreased relative expression of CDH1 gene was identified. In 100% of cases there was methylated status for the CDH1 gene, confirming the hypothesis that non-tumor cells can contribute to these results. In 46,5% of the cases reduced E-cadherin expression by immunohistochemistry was identified. Three tumor histotypes were identified: complex carcinoma, tubulopapillary, and carcinoma in mixed tumor. In 100% of cases of tubulopapillary carcinoma was identified a reduced gene expression of CDH1 by both qPCR and by immunohistochemistry. The sequencing of the gene, 6 animals (21,4%) had silent mutations in exons 3, 7 ... (AU)

• FAPESP's process: 13/05912-8 - Analysis of intraocular metastasis in female dogs suffering from mammary carcinoma and correlation with E-cadherin mutation and expression
• Grantee: Luciana Moura Campos Pardini
• Support Opportunities: Scholarships in Brazil - Master