N-Arachidonoyl Dopamine Inhibits NRAS Neoplastic Transformation by Suppressing Its Plasma Membrane Translocation

Abstract

RAS oncogenic mutations are common in human cancers, but RAS proteins have been difficult to target. We sought to identify pharmacological agents to block RAS oncogenic signaling by a distinct mechanism. Because the biological activity of RAS proteins relies upon lipid modifications and RAS regulates lipid metabolisms in cancer cells, we screened a bioactive lipid library using a RAS-specific cell viability assay. We report the discovery of a new class of inhibitors for RAS transformation. Compounds in the class represented by endocannabinoid N-arachidonoyl dopamine (NADA) can induce cell oncosis, independent of its ability to engage cannabinoid receptors. Further analyses show that NADA is more active in inhibiting the NRAS transformation and signaling than that of KRAS4B. Mechanistically, NADA blocks the plasma membrane translocation of NRAS, but not that of KRAS4B. In addition, NADA inhibits plasma membrane translocation and neoplastic transformation of oncogenic KRAS4A. Interestingly, NADA also redistributes the cytoplasmic NRAS to the Golgi apparatus in a palmitoylation-dependent manner. The results indicate that NADA inhibits NRAS and KRAS4A plasma membrane translocation by targeting a novel molecular process. The new findings would help to develop novel targeted therapies for a broad range of human cancers.

Molecular Mechanism of Cannabinoids in Cancer Progression

“…NADA has been shown to inhibit breast cancer cell growth in vitro and in vivo [37], in human osteosarcoma, lymphoma, and leukemia cell lines [38] and in colorectal carcinoma cells via activation of CB1R [23], while the inhibition of cell growth of neuroblastoma cells was mediated by TRPV1 receptor activation [39]. NADA inhibited plasma membrane translocation and neoplastic transformation of oncogenic KRAS4A redistributing the cytoplasmic NRAS to the Golgi apparatus [40]. In contrast, there is a limited effect of virodhamine on tumor progression.…”

GNA13 regulates BCL2 expression and the sensitivity of GCB-DLBCL cells to BCL2 inhibitors in a palmitoylation-dependent manner

“…Cell proliferation/viability were assessed using CellTiter-Glo Luminescent Cell Viability Assay (Promega, Madison, WI, USA) as previously described 52,53 . Briefly, cells were seeded into 96-well cell plates (5000 cells/well) and supplemented with drugs at various concentrations.…”

“…Western blot analysis was performed as previously described 53 . Briefly, cells were lysed in 1× sodium dodecyl sulfate (SDS) sample loading buffer, and then equal amounts of protein samples were loaded to polyacrylamide gel, transferred to nitrocellulose membrane, and then blotted with specific primary and secondary antibodies.…”

Combination therapy of BCR-ABL-positive B cell acute lymphoblastic leukemia by tyrosine kinase inhibitor dasatinib and c-JUN N-terminal kinase inhibition

“…Cell viability assays were carried out using the CellTiter-Glo® Luminescent Cell Viability Assay as previously described [23]. Cells were seeded into 96-well cell culture plates at a density of 5000 cells per well and added with indicated drugs at various concentrations.…”