Effect of miconazole on intracellular Ca 2+ levels and proliferation in human osteosarcoma cells Hong-Tai Chang a , Wei-Chung Chen b , Jin-Shyr Chen a , Yih-Chau Lu c , Shu-Shong Hsu a , Jue-Long Wang d , He-Hsiung Cheng e , Jin-Shiung Cheng e , Bang-Ping Jiann a , An-Jen Chiang f , Jong-Khing Huang a , Chung-Ren Jan g, T a Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 813 b Department of Surgery, Ping Tung Christian Hospital, Ping Tung, Taiwan 900 c Department of Orthopaedic Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 813 d Department of Rehabilitation, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 813 e Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 813 f Department of Obstetrics and Gynecology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 813 g Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 813 Received 11 March 2004; accepted 7 September 2004 Abstract The effect of miconazole, an anti-fungal drug, on cytoplasmic free Ca 2+ concentrations ([Ca 2+ ] i ) in human osteosarcoma cells (MG63) was explored by using the Ca 2+ -sensitive dye fura-2. Miconazole acted in a concentration-dependent manner with an EC 50 of 75 AM. The Ca 2+ signal comprised a gradual rise and a sustained elevation. Removal of extracellular Ca 2+ reduced 50% of the signal. In Ca 2+ -free medium, the [Ca 2+ ] i rise induced by 1 AM thapsigargin (an endoplasmic reticulum Ca 2+ pump inhibitor) was completely inhibited by pretreatment with 20 AM miconazole. Pretreatment with thapsigargin partly inhibited miconazole-induced Ca 2+ release. The miconazole-induced Ca 2+ release was not changed by inhibition of phospholipase C with 2 AM U73122. By using tetrazolium as a fluorescent probe, it was shown that 10–100 AM miconazole decreased cell proliferation rate in a concentration-dependent manner. Collectively, this study shows that miconazole induces [Ca 2+ ] i rises in human osteosarcoma cells via releasing Ca 2+ mainly from the endoplasmic reticulum in a manner independent of phospholipase C activity, 0024-3205/$ - see front matter D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.lfs.2004.09.033 * Corresponding author. Tel.: +886 7 3422121 1509; fax: +886 7 3468056. E-mail address: crjan@isca.vghks.gov.tw (C.-R. Jan). Life Sciences 76 (2005) 2091 – 2101 www.elsevier.com/locate/lifescie