A study explains how polyamines, such as spermidine, can both support healthy aging and promote cancer growth. Their effect depends on which of two similar proteins they activate. In healthy cells, polyamines activate eIF5A1, which supports cellular cleanup (autophagy) and normal mitochondrial energy production, contributing to healthy aging.
In cancer cells, polyamines activate a related protein called eIF5A2. This protein drives the production of growth-related genes and shifts energy production to rapid glycolysis, fueling aggressive tumor growth. Researchers also found that polyamines disrupt a natural regulatory molecule, miR-6514-5p, allowing eIF5A2 levels to rise in cancer cells.
The findings suggest that polyamine supplements may benefit healthy tissues but could potentially accelerate existing or hidden cancers. At the same time, eIF5A2 may serve as a selective treatment target, offering a way to block cancer growth without losing the anti-aging benefits linked to eIF5A1.