The effect of differential phosphorylation of YB-1 on apoptosis and cell cycle regulation

Abstract: The purpose of this study was to investigate whether different phosphorylated forms of Y-box binding protein (YB-1) can affect the regulation of the cell cycle and/or apoptosis of cancer cells. Recent studies have suggested a key role for YB-1 in the regulation of cancer. Just like many other oncoproteins YB-1 is required for vital processes in the cell and hence it is not possible to apply YB-1 in a therapeutic role. Therefore, my aim was to elucidate whether or not one or more phosphorylated forms of YB-1 play a decisive role in apoptosis. Human colorectal cancer cells (HCT 116) were transfected with different phosphorylated forms of YB-1. These cells were subsequently analysed by flow cytometry in order to compare live/dead cells between the different mutants. The results from this study suggest that one of the mutants (S176A) plays a more important role when it comes to protecting the cells from apoptosis and hence contribute to promoting sustained proliferation. Moreover, in opposite to S176A, the results indicate that another mutant (S167A) seems to have a more important role protecting the cells from sustained proliferation.