Fate of primary cells at the G₁/S boundary after polo-like kinase 1 inhibition by SBE13

Human polo-like kinase 1 (PLK1), a key regulator of mitosis, is over-expressed in various human tumors. It is a negative prognostic factor for Cancer patients and a measure for the aggressiveness of a tumor. Thus, targeting PLK1 might be a promising approach for Cancer therapy. PLK1 inhibitors represent attractive tools for Cancer research and for the mechanistic investigation of checkpoint control. Here, we show the impact of PLK1 inhibition on cell cycle regulation in primary cells. After treatment with SBE13 the G₁//S checkpoint was intact, indicated by reduced pRb, resulting in slower cell cycle progression but overall cell proliferation was not significantly impaired. Thus, we provide strong evidence that SBE13 leaves checkpoint control in primary cells unaffected making it a remarkable future anti-cancer therapeutic.