NSC668394 is a potent ezrin (Thr567) phosphorylation inhibitor, with a KD of 12.59μM[1]. NSC668394 decreases peripheral Ezrin content in neutrophils and increases calcium-dependent Ezrin cleavage, thereby preventing multiple and sustained morphological changes in neutrophils during prolonged chemotaxis[2]. NSC668394 reduces the connection between the cell membrane and the actin cortex, resulting in decreased membrane tension, accompanied by reduced surface area, increased cortical tension, remodeling of the actin cytoskeleton, and decreased cell height[3]. NSC668394 has been widely used in preclinical models to inhibit the growth of various tumors[4].
In vitro, NSC668394 treatment for 96h inhibited the viability of Rh41, Rh18, CCL-136, and Rh30 cells, with IC50 values of 2.766µM, 3.291µM, 4.115µM, and 7.338µM, respectively[5]. Treatment with 5µM NSC668394 for 24 hours inhibited the migration of fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis (RA) and reduced the formation of actin stress fibers[6].
In vivo, NSC668394 treatment via intraperitoneal injection at a dose of 13.5mg/kg/day for 9 days markedly suppressed tumor growth in the SU-DHL-6 xenograft mouse model and led to a decrease in the levels of pAkt, Bcl2, and Mcl1 in the tumors[7]. Intraperitoneal injection of NSC668394 (0.226mg/kg/day), five days a week for 7 weeks, inhibited the metastatic growth of osteosarcoma (OS) in the lungs of mice and improved the survival of mice[1].
References:[1] Bulut G, Hong S H, Chen K, et al. Small molecule inhibitors of ezrin inhibit the invasive phenotype of osteosarcoma cells[J]. Oncogene, 2012, 31(3): 269-281.
[2] Roberts R E, Elumalai G L, Hallett M B. Phagocytosis and motility in human neutrophils is competent but compromised by pharmacological inhibition of ezrin phosphorylation[J]. Current Molecular Pharmacology, 2018, 11(4): 305-315.
[3] Rouven Brückner B, Pietuch A, Nehls S, et al. Ezrin is a major regulator of membrane tension in epithelial cells[J]. Scientific reports, 2015, 5(1): 14700.
[4] Lipreri da Silva J C, Vicari H P, Machado-Neto J A. Perspectives for targeting ezrin in cancer development and progression[J]. Future pharmacology, 2023, 3(1): 61-79.
[5] Proudfit A, Bhunia N, Pore D, et al. Pharmacologic Inhibition of Ezrin‐Radixin‐Moesin Phosphorylation Is a Novel Therapeutic Strategy in Rhabdomyosarcoma[J]. Sarcoma, 2020, 2020(1): 9010496.
[6] Xiao Y, Sun M, Zhan Z, et al. Increased phosphorylation of ezrin is associated with the migration and invasion of fibroblast-like synoviocytes from patients with rheumatoid arthritis[J]. Rheumatology, 2014, 53(7): 1291-1300.
[7] Pore D, Bodo J, Danda A, et al. Identification of Ezrin-Radixin-Moesin proteins as novel regulators of pathogenic B-cell receptor signaling and tumor growth in diffuse large B-cell lymphoma[J]. Leukemia, 2015, 29(9): 1857-1867.