Monensin inhibits the growth of renal cell carcinoma cells via cell cycle arrest or apoptosis

• Published in: International journal of oncology Vol. 22; no. 4; p. 855
• Main Authors: Park, Woo Hyun, Jung, Chul Won, Park, Joon Oh, Kim, Kihyun, Kim, Won Seog, Im, Young Hyuck, Lee, Mark H, Kang, Won Ki, Park, Keunchil
• Format: Journal Article
• Language: English
• Published: Greece 01.04.2003
• Subjects: Antifungal Agents - pharmacology; Apoptosis; Blotting, Western; Carcinoma, Renal Cell - drug therapy; Caspases - metabolism; CDC2-CDC28 Kinases - metabolism; Cell Cycle; Cell Division; Cell Line; Cell Line, Tumor; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinases - metabolism; Cyclins - metabolism; Dose-Response Relationship, Drug; G1 Phase; G2 Phase; Humans; Inhibitory Concentration 50; Ionophores - pharmacology; Kidney Neoplasms - drug therapy; Microfilament Proteins - metabolism; Microscopy, Fluorescence; Monensin - pharmacology; Muscle Proteins; Phosphorylation; Precipitin Tests; Retinoblastoma Protein - metabolism; Sodium - metabolism
• ISSN: 1019-6439
• DOI: 10.3892/ijo.22.4.855

Previously, we showed that monensin, Na+ ionophore, potently inhibited the growth of acute myelogenous leukemia and lymphoma cells. Here, we demonstrate that monensin inhibited the proliferation of renal cell carcinoma cells with IC50 of about 2.5 micro M. Monensin induced a G1 or a G2-M phase arrest in these cells. When we examined the effects of this drug on ACHN cells, monensin decreased the levels of CDK2, CDK6, cdc2, cyclin A and cyclin B1 proteins. p21 and p27 proteins were increased by monensin. In addition, monensin markedly enhanced the binding of p21 with CDK2 and the binding of p27 with CDK6. Furthermore, the activities of CDK2- and CDK6-associated kinase were reduced in association with hypophosphorylation of Rb protein. Monensin also induced the apoptosis in several renal cell carcinoma cells. Apoptotic process of Caki-2 cells was associated with the changes of Bcl-2, Bcl-XL, caspase-9, caspase-3, caspase-7 proteins as well as mitochondria transmembrane potential (DeltaPsim) loss. Taken together, these results demonstrate for the first time that monensin inhibits the growth of renal cell carcinoma cells via cell cycle arrest or apoptosis.