Altered integrin expression patterns revealed by microarray in matched human melanomas (mRNA)

Metastatic process is considered the predominant cause of melanoma-specific death, decreasing survival dramatically, and resulting in difficulties in the effective treatment. Large variety of molecular pathways associated with disease development and progression suggests that no individual molecular alteration is crucial in these processes per se. Our aim was to gain insight into the molecular alterations behind metastasis formation, and to determine to what extent the profiles of primary melanoma and the corresponding metastasis are similar or distinct. High-throughput gene expression profiling was performed in combination with DNA microarrays to define significantly altered genes between matched primary and metastatic melanoma cell lines and tissue samples. Invasive behavior of different cell lines was determined using Matrigel invasion assays, and invasive primary clones were cultured selectively. Real-time qRT-PCR was applied to define integrin expression profiles of cell line pairs and melanoma tissue samples. A total of 4 human melanoma cell line pairs and 2 matched fresh/frozen primary lesions and lymph node metastatses were analyzed. Melanocyte was used as reference sample for the cell lines' expression data, whereas naevus (N=8 pooled samples) and normal skin (N=5 pooled samples) were applied as reference samples for the tissue expression data.