Netupitant Inhibits the Proliferation of Breast Cancer Cells by Targeting AGK

Background: Currently, there is a significant lack of effective pharmacological agents for the treatment of breast cancer. Acylglycerol Kinase (AGK), a lipid kinase, has been found to be aberrantly expressed in breast cancer and is closely associated with tumor proliferation, migration, and invasion. However, no clinical anti-tumor drugs specifically targeting this kinase have been developed. Methods: siRNA was utilized to knock down the AGK gene; CCK8 and colony formation assays were employed to evaluate the in vitro proliferative capacity of tumor cells. Molecular dynamics simulations and BIL assays were conducted to analyze drug binding affinity. Annexin V/PI staining was used to assess apoptotic phenomena; subcutaneous xenograft tumor experiments in nude mice were performed to confirm the in vivo anti-tumor efficacy of the drug. Results: Netupitant exhibited stable binding affinity for AGK and interacted with amino acids within the ATP-binding region of the enzyme. The IC₅₀ values for the SK-BR-3 and MDA-MB-231 cell lines were determined as 16.15 ± 4.25 µmol/L and 24.02 ± 4.19 µmol/L, respectively; at a concentration of 2.5 µmol/L, Netupitant effectively inhibited clonogenic capacity in breast cancer cells; furthermore, treatment with 10 µmol/L significantly induced apoptosis in these cells. Doses of 50 mg/kg and 100 mg/kg Netupitant markedly suppressed growth rates of subcutaneous xenograft tumors in nude mice while also promoting apoptotic processes. Both in vivo and in vitro studies indicated that Netupitant could inhibit the activation of the PI3K/AKT/mTOR signaling pathway. Conclusions: By targeting AGK, Netupitant inhibits its kinase activity, which leads to reduced phosphorylation levels of PTEN, thereby suppressing the activation of the PI3K/AKT/mTOR signaling pathway and ultimately resulting in apoptosis in breast cancer cells.