ADP Ribosylation Factor 6 Promotes Contraction and Proliferation, Suppresses Apoptosis and Is Specifically Inhibited...

Area of Science:

• Molecular Biology
• Cell Biology
• Urology

Background:

• Benign prostatic hyperplasia (BPH) involves prostate smooth muscle contraction and stromal cell proliferation, leading to voiding symptoms.
• ADP ribosylation factor 6 (ARF6) is a presumed regulator of these processes, but its specific role and inhibition by NAV2729 require validation.

Purpose of the Study:

• To generate and characterize ARF6 knockout prostate stromal cells.
• To determine the role of ARF6 in smooth muscle contraction and stromal cell growth.
• To assess the specificity and efficacy of NAV2729 in inhibiting ARF6-dependent functions.

Main Methods:

• Generated monoclonal ARF6 knockout WPMY-1 cells.
• Verified ARF6 knockout using Western blot.
• Assessed contractility, actin organization, proliferation, viability, apoptosis, and cell death in knockout and control cells.
• Evaluated the effects of NAV2729 (5 µM) on these parameters.

Main Results:

• ARF6 knockout cells exhibited impaired contraction, reduced proliferation and viability, and increased apoptosis.
• NAV2729 (5 µM) significantly inhibited contraction (67%), actin organization (72%), proliferation (97%), and viability (82%) in ARF6-expressing control cells.
• NAV2729's effects were markedly reduced in ARF6 knockout cells, demonstrating high specificity for ARF6.
• NAV2729 showed an IC50 of 3.3 µM for viability in control cells versus 4.5-8.2 µM in knockout cells.

Conclusions:

• ARF6 is crucial for prostate smooth muscle contraction and stromal cell proliferation.
• NAV2729 effectively and specifically inhibits ARF6-mediated functions up to 5 µM, indicating its therapeutic potential for BPH.
• The role of ARF6 in other smooth muscle tissues warrants further investigation due to its clinical relevance in smooth muscle diseases.