CK-666 exerts anticancer effects by regulating autophagy, tunneling nanotubes and extracellular vesicles formation

Area of Science:

• Cell Biology
• Molecular Oncology
• Biochemistry

Background:

• Actin-related protein complex 2/3 (Arp2/3) inhibitors like CK-666 affect cell migration.
• Limited research exists on CK-666's role in tumor therapy.
• Understanding CK-666's molecular mechanisms is crucial for potential therapeutic applications.

Purpose of the Study:

• To investigate the functional impact of CK-666 on tumor cells.
• To explore the relationship between CK-666, autophagy, exosomes, and tunneling nanotubes (TNTs).
• To evaluate CK-666's efficacy in 3D tumor models and its potential combination therapy with docetaxel.

Main Methods:

• RNA sequencing (RNA-seq) to analyze gene expression changes in CK-666 treated cells.
• Western blot to detect protein expression of autophagy and exosome markers.
• Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) to visualize cellular structures.
• 3D tumor spheroid and 3D-Histoculture Drug Response Assay (3D-HDRA) for in vitro and ex vivo efficacy evaluation.

Main Results:

• CK-666 treatment altered gene expression, linking it to exosomes and autophagy.
• High expression of exosome and autophagy markers was observed post-CK-666 treatment.
• CK-666 inhibited tunneling nanotubes (TNTs) formation and promoted CD63-positive vesicle secretion within retraction fibers.
• CK-666 demonstrated preferential inhibition of fibroblasts in 3D tumorspheres and suppressed isolated tumor tissue activity.
• Combination therapy with docetaxel (DTX) significantly enhanced DTX sensitivity.

Conclusions:

• CK-666 influences tumor cell behavior through modulation of autophagy, extracellular vesicles, and TNTs.
• The findings suggest a potential oncogenic role for CK-666.
• CK-666 shows promise in combination therapy to enhance the efficacy of existing chemotherapeutics like docetaxel.