PAK6 acts downstream of IQGAP3 to promote contractility in triple negative breast cancer cells

Area of Science:

• Oncology
• Cell Biology
• Molecular Biology

Background:

• Breast cancer is a leading cause of cancer death in women globally.
• Triple-negative breast cancer (TNBC) is an aggressive subtype with limited targeted therapies.
• IQGAP3 is a protein found to be upregulated in TNBC tumors.

Purpose of the Study:

• To investigate the role of IQGAP3 in TNBC cell behavior.
• To elucidate the molecular mechanisms underlying IQGAP3's function in breast cancer.

Main Methods:

• Depletion of IQGAP3 expression in TNBC cell lines.
• Analysis of cell morphology, migration, and invadopodia formation.
• Assessment of RhoA activity and actomyosin contractility.
• Investigation of the interaction between IQGAP3 and PAK6.

Main Results:

• IQGAP3 depletion caused cell elongation, reduced migration, and inhibited invadopodia formation.
• IQGAP3 regulates cell morphology and invasion via the RhoA pathway.
• IQGAP3 interacts with PAK6, and PAK6 plays a crucial role in the observed phenotype.

Conclusions:

• A novel PAK6-IQGAP3-RhoA pathway is identified, driving breast cancer cell contractility, migration, and invasion.
• This pathway is critical for metastasis and re-seeding of tumors.
• Pharmacological targeting of PAK6 presents a potential therapeutic strategy for TNBC.