Polyamine metabolic and transport system

The polyamine metabolic and transport system is a highly regulated network of enzymes and transporters that maintains the levels of the polycations putrescine, spermidine, and spermine within the cell (1.1.2, 1.3.1). These molecules are essential for fundamental biological processes, including the stabilization of nucleic acids, regulation of ion channels, and the hypusination of eukaryotic translation initiation factor 5A (eIF5A), which is critical for protein synthesis (1.1.4, 1.3.3). In many cancers, such as neuroblastoma and colorectal cancer, this pathway is frequently hijacked and upregulated to support rapid cell proliferation and survival (1.2.1, 1.2.3). Therapeutic intervention typically involves the use of inhibitors for rate-limiting enzymes like ornithine decarboxylase (ODC) or the blockade of the polyamine transport system (PTS) to starve cells of exogenous polyamines (1.2.2, 1.2.4). Modern strategies, such as polyamine blocking therapy (PBT), combine biosynthesis inhibition with transport blockade to achieve more effective intracellular polyamine depletion (1.2.5). Additionally, polyamine analogs are used to induce catabolic enzymes, further reducing the polyamine pool and triggering apoptosis in malignant cells (1.2.3).

Other names

Polyamine pathwayPolyamine transport systemPolyamine metabolic pathwayPolyamine transporters and metabolic enzymes

Inhibition of polyamine biosynthesis (e.g., ODC, SAMDC), inhibition of polyamine uptake via the transport system, and induction of polyamine catabolism (e.g., SSAT, PAO) to deplete intracellular polyamine pools.