[The serine/threonine kinases that control cell cycle progression as therapeutic targets]

Cell cycle progression corresponds to a series of events, which succeed one another to end in the division of a mother cell to give two daughter cells. The processes that allow the cell to divide are very precisely controlled by a multitude of enzymatic reactions among which protein phosphorylation, carried out by protein kinases, plays a key role. Serine/threonine kinases are enzymes that catalyse the transfer of a phosphate from ATP to a protein substrate, more precisely on a serine or threonine amino acid residue. Three important families of serine/threonine kinases are involved in the regulation of cell cycle progression, the cyclin dependent kinase (CDK) the polo-like kinase (PLK) and those of the Aurora family. The cancer is described as an uncontrolled cell division process. Cancer cells proliferate indeed in an anarchic way, and carry out cycles of cellular division by being unaware of the signals of alarm. A simple idea thus appeared soon: to stop or to slow down cell cycle progression would result in inhibiting cell proliferation and thus fighting against cancer. Cell cycle progression being controlled in particular by protein kinases of the CDK, PLK and Aurora families, it was rapidly decided to look for inhibitors of those protein kinases. We will first make a general recall on cell cycle progression and the mechanisms that control it. The functions of protein kinases of the CDK, PLK and Aurora families will then be described by concentrating on the sensitive phase of the cell cycle progression, i.e. mitosis. Finally, we will approach the consequences of the inhibition of these protein kinases within the framework of the fight against cancer.