Matrix rigidity differentially regulates invadopodia activity through ROCK1 and ROCK2

Area of Science:

• Cell Biology
• Biophysics
• Cancer Research

Background:

• Tumor microenvironment (TME) rigidity increases Rho-associated coiled-coil kinase (ROCK) activity, promoting cancer cell malignancy and invasion.
• Invadopodia, actin-rich protrusions, are crucial for extracellular matrix (ECM) degradation and invasive migration.
• ROCK-dependent actomyosin contractility is implicated in invadopodia regulation, but isoform-specific roles remain unclear.

Purpose of the Study:

• To investigate the distinct roles of ROCK1 and ROCK2 isoforms in regulating invadopodia activity in response to matrix rigidity.
• To elucidate the signaling pathways through which ROCK isoforms mediate rigidity-dependent invadopodia function.

Main Methods:

• Utilized cancer cell models cultured on matrices of varying rigidity.
• Assessed invadopodia formation, ECM degradation, and cell migration.
• Employed biochemical assays and pharmacological inhibitors to dissect ROCK1 and ROCK2 signaling pathways, including non-muscle myosin II (NM II) and LIM kinase (LIMK).

Main Results:

• Matrix rigidity significantly enhanced ROCK signaling in cancer cells.
• ROCK1 and ROCK2 were found to differentially regulate invadopodia activity.
• ROCK1 primarily mediated invadopodia activity through non-contractile LIMK pathways, while ROCK2 utilized contractile NM II pathways.

Conclusions:

• ROCK1 and ROCK2 isoforms play distinct, non-redundant roles in regulating invadopodia-dependent cancer cell invasion.
• Mechanical cues from the TME, specifically matrix rigidity, activate distinct ROCK isoform-specific signaling pathways.
• Targeting these differential ROCK pathways may offer novel therapeutic strategies to inhibit cancer progression and metastasis.