Gene expression of the MAPK pathway in osteosarcoma

Abstract

Osteosarcoma (OS) is the most common malignant bone tumor in adolescents. A feature of the OS is its high risk of metastasis, and the lung is the most frequent site of metastasis. Unlike other bone sarcomas and soft tissue, OS does not have known genetic changes that serve as disease markers and assist in diagnosis. Recent studies using CGH (Comparative Genomic Hybridization) revealed several numerical chromosomal abnormalities involving regions 1p36.3, 17p, and chromosome 19. In a previous study from our group, we evaluated the expression of 10 genes located in these chromosomal regions of gain in OS (1p36, 17p, and chromosome 19), and we found an increase in MAPK7 gene expression in biopsy samples (pre-chemotherapy) when compared to surgery samples (post-chemotherapy). This study suggests that this increased expression may be contributing to the worst response treatment and therefore a worse overall survival. To understand the relationship between the OS genesis process and the MAPK pathway, we will investigate the expression of genes involved in the MAPK pathway. We have selected five genes that control MAPK7 gene "upstream" (MAP2K5, MAP2K6, MAP3K1, MAP3K3, MAP4K3) and one gene antagonist to the pathway, the DUSP1 gene (MKP1). We will relate the genes expression profile with clinical and pathologic features of patients.(AU)