First molecules to reactivate RAS^G12V GTPase activity.

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• RAS^G12V mutation is a target for anticancer therapy.
• Restoring GTPase activity of RAS^G12V is a therapeutic goal.
• Previous attempts to find such compounds have been unsuccessful.

Purpose of the Study:

• To identify small-molecule compounds that restore GTPase activity of RAS^G12V.
• To investigate the mechanism of action and efficacy of these compounds.
• To evaluate their potential as anticancer therapeutics.

Main Methods:

• Virtual screening for compound identification.
• Flexible docking to determine optimal binding conformation.
• In vitro assays including IC50 determination, GTPase activity assays, and Western blotting for AKT and ERK phosphorylation.

Main Results:

• Compounds demonstrated significantly lower IC50 values in RAS^G12V-mutated cells compared to normal cells.
• Proposed mechanism involves minimizing the V12 sidechain's negative impact on RAS^G12V GTP hydrolysis.
• Observed that RAS^G12V mutation does not always correlate with increased AKT and ERK activity in cell lines.

Conclusions:

• Demonstrated novel molecules that partially restore RAS^G12V GTPase activity.
• Mechanism aligns with current models of RAS mutant conformation and function.
• Compounds inhibit the RAS-AKT pathway, exhibiting higher cytotoxicity against SW-480 cancer cells.
• SW-480 cells can develop resistance through AKT-independent proliferation.