Stratifying fascin and cortactin function in invadopodium formation using inhibitory nanobodies and targeted...

Area of Science:

• Cell Biology
• Cancer Research
• Biochemistry

Background:

• Invadopodia are critical actin-rich structures enabling cancer cell invasion.
• Understanding the specific roles of proteins like fascin and cortactin in invadopodia formation is key to targeting cancer metastasis.

Purpose of the Study:

• To investigate the precise functions of fascin and cortactin in invadopodium formation and cancer cell invasion using nanobodies.
• To elucidate the contribution of fascin-F-actin bundling and cortactin domains to invadopodia dynamics and extracellular matrix degradation.

Main Methods:

• Utilized nanobodies as specific intracellular perturbators to disrupt fascin and cortactin functions in MDA-MB-231 (breast) and PC-3 (prostate) cancer cells.
• Employed a subcellular delocalization strategy to induce protein loss-of-function and assess fascin's role in MMP-9 secretion.

Main Results:

• A fascin-targeting nanobody highlighted the importance of F-actin bundling for invadopodia organization, matrix degradation, and cell invasion.
• A cortactin nanobody inhibited WIP recruitment, demonstrating the cortactin-SH3 domain's role in invadopodia organization, MMP-9 secretion, and invasion.
• Fascin was found to play a role in MMP-9 secretion independent of its F-actin bundling activity.

Conclusions:

• Nanobodies are powerful tools for high-resolution mapping of protein functions within living cells.
• Fascin and cortactin are essential regulators of invadopodia formation, matrix degradation, and cancer cell invasion, with distinct and overlapping functions.
• Targeting fascin and cortactin pathways offers potential therapeutic strategies against cancer metastasis.