Expression profiling of angiogenesis-related genes in brain metastases of lung cancer and melanoma

Brain metastases (BM) are the most common brain tumors of adults and are associated with fatal prognosis. Formation of new blood vessels, named angiogenesis, was proposed to be the main hallmark of the growth of BM. Previous preclinical evidence revealed that angiogenic blockage might be considered for treatment; however, there were varying responses. In this study, we aimed to characterize the expression pattern of angiogenesis-related genes in BM of lung cancer and melanoma, which might be of importance for the different responses against anti-angiogenic treatment. Fifteen snap-frozen tissues obtained from BM of non-small cell lung cancer (NSCLC), small-cell lung cancer (SCLC), and melanoma patients were analyzed for angiogenesis-related genes using a commercially available gene expression kit. Epilepsy tissue was used as control. Expression values were analyzed using hierarchical clustering investigating relative fold changes and mapping to Omicsnet protein interaction network. CXCL10, CEACAM1, PECAM1, KIT, COL4A2, COL1A1, and HSPG2 genes were more than 50-fold up-regulated in all diagnosis groups when compared to control, whereas genes such as ANGPT4, PDGFRB, and SERPINF1 were down-regulated only in SCLC and melanoma groups, respectively. Using hierarchical clustering, 12 out of 15 cases were allocated to the correct histological primary tumor type. We identified genes with consistent up-regulation in BM of lung cancer and melanoma and other genes with differential expression across BM of these tumor types. Our data may be of relevance for targeted therapy or prophylaxis of BM using anti-angiogenic agents.