Summary
Published in Bioscience Reports (2023), this peer-reviewed study used 3D Petri Dish® micro-molds to form scaffold-free 3D microtissues. Full citation: Küster, Lukas, et al. The actin bundling activity of ITPKA mainly accounts for its migration-promoting effect in lung cancer cells
The actin bundling activity of ITPKA mainly accounts for its migration-promoting effect in lung cancer cells
Research Overview
ITPKA, the neuronal isoform of Ins(1,4,5)P3-kinases, is upregulated in many tumors; in lung cancer that upregulation predicts poor prognosis and raises migration and invasion. But ITPKA has two activities — actin bundling and Ins(1,4,5)P3 kinase — and which one drives the aggressive phenotype was unresolved.
The authors inhibited only the actin-bundling activity in H1299 lung cancer cells by overexpressing the dominant-negative mutant ITPKA-L34P. Analysis of actin dynamics in filopodia and wound-healing migration showed both were inhibited, and the formation of invasive protrusions into collagen I was strongly blocked — implicating actin bundling, not kinase activity, as the main driver.
Key Discoveries
- Dominant-negative ITPKA-L34P isolated the actin-bundling activity from kinase activity
- Filopodial actin dynamics and wound-healing migration were both inhibited
- Invasive protrusion into collagen I was strongly blocked, implicating actin bundling in invasion
