P-308 Novel gold (III) TGS121 complex selectively affects proteostasis of Ras-hyperactivated colorectal cancer cells via a shift in signaling pathways

According to the GLOBOCAN, colorectal cancer (CRC) is second leading cause of deaths. Thus, new therapies for CRC are urgently needed. In search drug, our team studied a series cyanide gold (III) complexes (International Patent No: WO219008013A1). Our initial studies on cancerous RAS-3T3 and non-cancerous NIH-3T3 murine fibroblasts showed that complex known as TGS121, [Au(CN)4]2 (ClO2)Na, has significant cytotoxicity selectivity towards Ras-hyperactivated cells. this work, analyzed mechanisms action TGS121 in human RAS-mutated cell model, since one most frequent genetic alterations results Ras hyperactivation. The was assessed (Lovo, SW837) non-RAS-mutated (Caco-2) cycle phases distribution, morphology ultrastructure under transmission electron microscope (TEM) were analyzed. Due observed formation aggresomes treatment, we suspected proteostasis, thus performed an in-depth analysis proteostasis-related parameters. Crystal structure 20S proteasome with Bortezomib retrieved (PDB ID: 5LF3) from RCBS PDB database molecular docking Au(CN)4- using Induced Fit Docking application, which combines Grid-based Ligand Energetics (GLIDE) Prime refinement modules. Next, vitro test chymotrypsin-like (β5c subunit) activity assessed. Immunocytochemical staining aggresome performed. To assess signaling pathways, ELISA assays phospho-ERK -AKT Finally, determine safety profile viability peripheral blood mononuclear cells (PBMC). exhibits antiproliferative properties against Lovo SW837 At concentrations lethal cells, does not reduce PBMC or TEM images mitochondrial swelling, endoplasmic reticulum (ER) dilation, features paraptosis. There no characteristic apoptosis signs TEM. addition, block G2/M phase observed. Molecular indicates can form stable all three subunits: β1c, β2c β5c, slight preference acting noncovalent inhibitor. β5c subunit decreased after treatment. dose-dependent increase phosphorylated-AKT decrease phosphorylated-ERK incubation indicate shift signaling. This induced selectively by TGS121. induces paraptotic death reducing activity, causing ER stress, ERK AKT effect blocking adequate strongly affected variance arise upregulation protein synthesis, additional inhibition 19S regulator, tripeptidyl peptidase 2. Investigation these interactions prospective avenue future research.