A melanoma octamer binding protein is responsive to differentiating agents.

Analysis of human melanocytes and melanoma cell lines for proteins interacting with the octamer control sequence (ATGCAAAT) has revealed two distinct melanoma octamer binding proteins, Oct-M1 and Oct-M2. The latter was restricted to cell lines derived from tumor metastases. The level of Oct-M1 activity in a pigmented melanoma line was enhanced in comparison to the general octamer binding protein Oct-1 when cells were cultured in the presence of the depigmenting agent dithiothreitol and conversely was reduced by the differentiating and pigment inducing agents butyric acid and dimethyl sulfoxide.