Expression of HERV-K correlates with status of MEKERK and p16INK4ACDK4 pathways in melanoma cells

The dysregulated ERK and RB pathways often coexist in melanoma cells. The K-type human endogenous retrovirus (HERV-K) is implicated in melanomagenesis. Some of the phenotypes that are modified by HERV-K (e.g., changes in cell shape, melanin production, and anchorage-dependent growth) overlap with those that are regulated by ERK and RB pathways. As ERK signaling can regulate retroviruses, we hypothesized that HERV-K expression is controlled by ERKRB pathways. We found that the levels of HERV-K GAG and EVE correlated with the activation of ERK and loss of p16INK4A and that inhibition of MEK or CDK4, especially in combination, reduced HERV-K EVE in melanoma cells.