Distinct MHC gene expression patterns during progression of melanoma.

Abnormal expression of major histocompatibility complex (MHC) molecules in melanoma has been reported previously. However, the MHC molecule expression patterns in different growth phases of melanoma and the underlying mechanisms are not well understood. Here, we demonstrate that in vertical growth phase (VGP) melanomas, MHC genes are subject to increased rates of DNA copy number gains, accompanied by increased expression, in comparison to normal melanocytes.