Dados do Trabalho

Título

GENE EXPRESSION PROFILE EVALUATION ON BREAST TUMORS WITH BRAIN METASTASES

Introdução

Breast cancer are the main cause of related deaths cancer among women, corresponding to 25% of new cases each year. When diagnosed at early stages, it has an overall five-year survival rate of up to 90%. However, in more advanced stages, survival is reduced to about 24%, with 90% of women in stage IV dying as a result of complications related to metastases. Brain is one of the most common site of metastases in breast cancer patients with poor prognosis without a therapeutic approach. When treatment options are available, only 20% of patients survive more than 1 year. Considering that the metastases brain is an unfavorable prognostic site, and the identification of genetic-molecular profiles in primary tumors and in metastatic sites are a subject poorly described in the literature, we understand that the identification of genetic profiles may contribute to elucidate the genetic-molecular mechanisms associated with tumor progression.

Objetivo

The aim of this study was to identify the gene expression profile in breast tumors and paired brain metastases.

Método

For gene expression analysis, automated extraction of RNA from paraffin material of breast tumors and paired brain metastases (n=11) from biopsy or surgical resection was performed. This study evaluated the expression of 770 genes related to tumor biology, immune response and tumor microenvironment using NanoString platform. Data analysis was performed using NanoStringNorm program and FDR method of normalization. T test was performed for statistical significance considering p value ≤0.05 and fold-change ≥2.

Resultado

We identify a gene expression profile of 87 genes in primary tumors different expressed when compared with brain metastases. Among these genes are CTLA4, JAK3, CD45RO and CYBB2 that are related to immune response, and VCAM1 and MMP9 that are related to the metastasis process.

Conclusão

This data suggests that the molecular-genetic profile from brain metastasis differs from the primary tumor, bringing new perspectives in identifying mechanisms associated with the metastasis process.

Palavras-chave

Breast cancer, brain metastasis, gene expression.