Targeting cancer metabolism by simultaneously disrupting parallel nutrient access pathways.

Oncogenic mutations drive anabolic metabolism, creating a dependency on nutrient influx through transporters, receptors, and macropinocytosis. While sphingolipids suppress tumor growth by downregulating nutrient transporters, macropinocytosis and autophagy still provide cancer cells with fuel. Therapeutics that simultaneously disrupt these parallel nutrient access pathways have potential as powerful starvation agents.

Rab7 activation by growth factor withdrawal contributes to the induction of apoptosis.

The Rab7 GTPase promotes membrane fusion reactions between late endosomes and lysosomes. In previous studies, we demonstrated that Rab7 inactivation blocks growth factor withdrawal-induced cell death. These results led us to hypothesize that growth factor withdrawal activates Rab7.

A new take on ceramide: starving cells by cutting off the nutrient supply.

Ceramide generation is increased by a broad array of signals. In general, ceramide limits cell survival and proliferation and promotes differentiation and senescence. Despite its role in the pathogenesis of multiple human diseases, ceramide's mechanism of action remains poorly defined.

Ceramide starves cells to death by downregulating nutrient transporter proteins.

Ceramide induces cell death in response to many stimuli. Its mechanism of action, however, is not completely understood. Ceramide induces autophagy in mammalian cells maintained in rich media and nutrient permease downregulation in yeast.