Up to 75% of stage IV melanoma patients develop brain metastases during the course of their disease. Brain metastases are associated with a median overall survival of only 3-6 months. Although there is concordance in the mutational landscape of intra- and extracerebral metastases, patients with brain metastases do not sufficiently respond to most therapies. This indicates specific resistance mechanisms.
To identify new prognostic and predictive biomarkers and to uncover mechanisms responsible for the different biological behavior in melanoma brain metastases, we have already established a worldwide unique cohort of 27 pairs of intra- and extracranial metastases with a complete clinical follow up as well as 40 melanoma intracerebral metastases for validation. In order to identify proteins and pathways that are responsible for the different biological behavior, we will
(1) identify differences in epigenetic modifications of genes by executing an Illumina 450k methylation array.
(2) simultaneously characterize differences in messenger RNA expression executing RNA-Seq by using the Illumina TruSeq RNA Access-protocol.
(3) validate identified differences in gene modification/messenger RNA expression and signaling pathways by conventional immunohistochemistry and correlation with clinical outcome.
(4) execute functional in vitro experiments that include standard cell culture methods to elucidate differences in survival, apoptosis, autophagy, cell cycle, migration, invasion, and colony formation.
- Define target proteins and pathways that are associated with treatment resistance in melanoma brain metastases and can be used for further in vivo experimental and clinical studies.
- Discover new prognostic markers as well as novel molecular targets for future therapeutic approaches to treat melanoma patients with brain metastases.