Rosuvastatin induces apoptosis in cultured human papillary thyroid cancer cells N Dilara Zeybek 1 , Nese Ersoz Gulcelik 2 , F Figen Kaymaz 1 , Can Sarisozen 4 , Imran Vural 4 , Ebru Bodur 3 , Hande Canpinar 5 , Aydan Usman 2 and Esin Asan 1 Departments of 1 Histology and Embryology, 2 Endocrinology and Metabolism and 3 Medical Biochemistry, Faculty of Medicine, Hacettepe University, Sihhiye, Ankara 06100, Turkey 4 Department of Pharmaceutical Technology, Facultyof Pharmacy, Hacettepe University, Ankara 06100, Turkey 5 Department of Basic Oncology, Oncology Institute, Hacettepe University, Ankara 06100, Turkey (Correspondence should be addressed to N D Zeybek; Email: dilaraz@hacettepe.edu.tr) Abstract Statins show antiproliferative activity in various cancer cells. The aim of this study was to evaluate the effects of rosuvastatin treatment on papillary thyroid carcinoma. The papillary thyroid carcinoma (B-CPAP) and normal (Nthy-ori 3-1) thyroid cell lines were treated with rosuvastatin at 12 . 5, 18 . 5, 25, 50, 100, and 200 mM concentrations. After 48 and 72 h of rosuvastatin treatment, 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide, Ki-67 immunolabeling, FACS analysis, electron microscopy, caspase-3, and terminal deoxynucleotidyl transferase-mediated dUTP nick end- labeling (TUNEL) analysis were performed. Decreased cell viability and G1 phase arrest were detected in papillary thyroid cell line treated with rosuvastatin. Positive immunoreactivityof Ki-67 and dose-dependent increase in S phase on Nthy-ori 3-1 cells were also detected. B-CPAP cells showed intense vacuolisation and autophagosomes with low concentrations and 48 h incubations, while Nthy-ori 3-1 cells showed these changes at higher concentrations. A decrease in the percentage of cells showing autophagy was determined with increasing concentrations of rosuvastatin in B-CPAP cells. Rosuvastatin treatment also caused a dose- and time-dependent increase in caspase-3 activity and apoptotic index by TUNEL assay in B-CPAP cells compared with the Nthy-ori 3-1 cells. Apoptotic cells with nuclear condensation and fragmentation were observed in B-CPAP cell line. Rosuvastatin induced autophagic changes in B-CPAP papillary thyroid cancer cells in lower doses and caused a shift from autophagy to apoptosis. Rosuvastatin may be an alternative treatment for refractory papillary thyroid cancer. Further in vivo studies are necessary to clarify the effects of rosuvastatin in papillary thyroid carci- noma and the clinical implications of rosuvastatin treatment. Journal of Endocrinology (2011) 210, 105–115 Introduction Statins are the competitive inhibitors of 3-hydroxy-3- methylglutaryl CoA (HMG-CoA) reductase and are routinely used for the treatment of hypercholesterolemia. The enzyme HMG-CoA reductase catalyses the conversion of HMG-CoA to mevalonate (Goldstein & Brown 1990). Inhibition of mevalonate by statins leads to a decrease in both cholesterol and important intermediate metabolites, such as the isoprenoids, farnesyl pyrophosphate, and geranylgeranyl pyrophosphate, which are involved in the post-translational prenylation of several proteins (i.e. Ras, Rho, and Rac) that modulate a variety of cellular processes, including cellular signaling, differentiation, proliferation, and apoptosis (Alegret & Silvestre 2006, Katsiki et al. 2009). HMG-CoA reductase inhibition displays immunomodula- tory, anti-inflammatory and anti-oxidant activity, which is unrelated to the effects on lipid metabolism (Bifulco 2008). A number of studies demonstrated antineoplastic effects of statins (Campbell et al. 2006, Sivaprasad et al. 2006, Lin et al. 2008). The antiproliferative effects of statins were demonstrated in in vitro studies on hepatocellular carcinoma (Kawata et al. 1994), lung (Hawk et al. 1996), breast (Campbell et al. 2006), and pancreatic cancer cells (Gbelcova ´ et al. 2008). These effects appear to be generated either via effects on cell cycle and induction of growth suppression or via induction of apoptosis of malignant cells (Sassano & Platanias 2008). There are limited studies on the antiproliferative effect of statins on thyroid cells, which were performed on prolifera- ting rat thyroid cells or anaplastic thyroid cancer cells. Bifulco et al. (1999) showed the antiproliferative and/or proapoptotic activity of lovastatin in proliferating rat thyroid cells. Zhong et al. (2003) demonstrated the effectiveness of lovastatin in the treatment of anaplastic thyroid cancer in in vitro studies. To our knowledge, there is no studyon the effect of statin treatment on differentiated thyroid cancer cells. Moreover, the effect of statin treatment on thyroid growth is of clinical interest. Recently, Cappelli et al. (2008) reported decreased 105 Journal of Endocrinology (2011) 210, 105–115 DOI: 10.1530/JOE-10-0411 0022–0795/11/0210–105 q 2011 Society for Endocrinology Printed in Great Britain Online version via http://www.endocrinology-journals.org Downloaded from Bioscientifica.com at 02/18/2023 10:00:43AM via free access