CBDA stimulated lamellipodia formation at the leading edge, whereas NSC23766 (an established Rac1 inhibitor) completely blocked this elongated morphology. Biochemical analyses, including time-lapse imaging and confocal laser scanning microscopy, revealed that, compared to Y-27632, CBDA can induce impaired tail retraction coupled with unidirectional elongation of the cell body, upregulate the mRNA expression of DIAPHs, and accumulate vinculin, an adhesion protein, at the trailing edge without affecting its expression. These results indicate the potential of CBDA as a new candidate for the synthesis of ROCK inhibitors, which can evoke the directed elongation of MDA-MB-231 cells.

Targeting the Rac1 pathway with small molecule inhibitors (NSC23766, R-ketorolac) reduces survival and motility in resistant cells, inhibits in vivo Rac1 activity, and reduces tumour burden when combined with tamoxifen in a drug-refractory patient derived xenograft model. This work identifies the P-Rex1/Rac1 axis as a potential therapeutic target for late recurring ER+ breast cancer.

In vivo studies with immunocompromised mice bearing HER2-BM tumors demonstrated that M6 inhibits tumor growth and metastasis to the lungs, livers, and kidneys by ~90%, comparable to MBQ-167. These findings suggest that M6 exhibits potent anticancer properties both in vitro and in vivo, potentially contributing to the sustained efficacy of MBQ-167 in metastatic breast cancer.

Critically, pharmacological inhibition abolished GGPPS-driven geranylgeranylation-dependent signaling: JSH-23 reversed both the proliferation mediated by RHOA and NF-κB p65 and the upregulation of IL1B potentiated by GGPS1 overexpression; and NSC23766 blocked the RAC1/STAT1-dependent IL1RAP activation amplified by GGPPS elevation, confirming that both axes are indispensable for GGPPS-dependent proliferation. Collectively, this GGPPS-mediated geranylgeranylation axis, converging on IL-1 pathway amplification, represents a central therapeutic vulnerability in LUSC, highlighting GGPPS as a promising macromolecular target for this recalcitrant malignancy.

Notably, pharmacological inhibition of Rac1 activation with NSC23766 abolished OTUB2-mediated hypertrophic responses in PE-treated cardiomyocytes. Our findings establish the OTUB2/Rac1 axis as a novel regulator of pathological cardiac hypertrophy and a potential therapeutic target for cardiac remodeling.

This study identifies the Rac1-USP11 reciprocal feedback loop as a novel, self-reinforcing mechanism driving radioresistance in HCC. Targeting this loop via combined Rac1-GTP/USP11 inhibition represents a promising therapeutic strategy for radiosensitizing HCC.

Expression of myogenesis and inflammation markers, GLUT4 translocation, [3H]2-deoxyglucose uptake, and intramyocellular insulin signalling were determined...Moreover, breast cancer CM inhibits basal and insulin-mediated GLUT4 translocation and glucose uptake, likely by blocking insulin-stimulated Rac1, but not Akt-TBC1D4 activation. These results underscore a potential mechanistic link between breast cancer and metabolic disorders and suggest that skeletal muscle rewiring may play a role.

NSC23766, a RAC1 GTP inhibitor, was employed to identify the pathway-specific effects...RAC1 overexpression portends poor HCC prognosis and mediates radioresistance through GTP-dependent activation of antiapoptotic pathways and cell cycle modulation. Targeting RAC1 GTP activity may enhance the radiosensitivity of HCC.

RAC1 genetic or GYS32661 mediated inhibition leads to RAC1 dissociation from the GLI1 promoter and transcriptional repression of Shh-MB biomarkers GLI2, DNMT1 and UHRF1. This eventually causes inhibition of Shh-MB tumor cell proliferation and migration, which leads to a decrease in Shh-MB development.

The translational relevance of these findings is underscored by the growth inhibition observed in patient-derived BPH organoids treated with NSC23766. In conclusion, our findings identify TIAM1 as a key driver of prostatic branching and growth, and suggest that targeting TIAM1-RAC1 signaling could be a promising therapeutic strategy for BPH.

P1, N=48, Recruiting, MBQ Pharma | Trial completion date: Oct 2024 --> Oct 2025 | Trial primary completion date: Oct 2024 --> Oct 2025

Importantly, inhibition of Rac1 GTPase activity with NSC23766 significantly reduced DHA-mediated haemolysis, as did co-administration of either sucrose or polyethylene glycol 8,000. Conversely, the presence of 125 mM KCl and urea without extracellular Ca2+ significantly exacerbated DHA toxicity. In conclusion, this is the first report that identifies key biochemical mechanisms underlying the cytotoxic effects of DHA in RBCs, promoting further development and validation of DHA in anticancer therapy.