First molecules to reactivate RAS GTPase activity.

BACKGROUND

Small-molecule compounds that even partially restore the GTPase activity of RAS can be used in anticancer therapy. Until now, attempts to obtain such compounds have failed. Compounds with this ability have been defined in our research.

METHODS

The compounds were initially identified through virtual screening, and their optimal binding conformation in the RAS SW-II pocket was determined using the flexible docking technique. Efficacy was verified based on the IC50 determination, GTPase activity, as well as the AKT and ERK phospho WB assays.

RESULTS

The IC50 of the tested compounds was significantly lower against cells with the RAS mutation than against selected types of normal cells. The molecular mechanism of action of these compounds was proposed - minimization of the negative impact of the V12 sidechain on GTP hydrolysis of RAS. The work also indicates that the model of action of RAS mutants in cell lines is incomplete. The analysed cell line (SW-480) with RAS mutations does not always show increased ERK and AKT activity.

CONCLUSIONS

We have demonstrated molecules that partially restore the GTPase activity of RAS. Their mechanism of action is well explained based on current RAS mutant conformation and mechanistic models. These molecules inhibit the RAS-AKT pathway and show higher cytotoxicity against cancer cells with the RAS mutation (SW-480 cell line). However, SW-480 cells can switch into the subline proliferating independently of AKT phosphorylation and show partial resistance to the molecules described in this article.