Between Scylla and Charibdis: eIF2α kinases as targets for cancer chemotherapy.

The eIF2α kinases integrate translation initiation rates with nutrient availability, thus allowing cells to adapt to nutrient scarcity. Recent evidence has uncovered new functions of these kinases in tumour cell biology, ranging from regulation of cell cycle progression, maintenance of genome stability, control of apoptosis, and cell survival under nutrient stress and hypoxia. Accordingly, active eIF2α kinases modulate the antineoplasic activity of several antitumour drugs, either by exacerbating their cytotoxic effect or by promoting chemoresistance. Understanding of eIF2α kinases molecular roles may provide mechanistic insights into how tumour cells sense and adapt to nutrient restriction, thus helping to implement more effective approaches for cancer chemotherapy.