RESEARCH ARTICLE Temozolomide may induce cell cycle arrest by interacting with URG4/URGCP in SH-SY5Y neuroblastoma cells Veli Çıtışlı 1 & Yavuz Dodurga 2 & Canan Eroğlu 2 & Mücahit Seçme 2 & Çığır Biray Avcı 3 & N. Lale Şatıroğlu-Tufan 4 Received: 18 March 2015 /Accepted: 24 March 2015 # International Society of Oncology and BioMarkers (ISOBM) 2015 Abstract Temozolomide (TMZ) is an alkylating drug used usually in glioma treatment by inducing the apoptosis in glio- ma cell. The aim of the study is to investigate the anticancer mechanism of TMZ in SH-SY5Y human neuroblastoma cell line. Cytotoxic effects of TMZ were determined by using XTT assay. IC 50 doses in the SH-SY5Y were detected as 5 mM. Expression profiles of novel genes URG4/URGCP , CCND1, CCND2, CDK4, and BCL2 were determined by real-time PCR. The apoptotic effects of TMZ were evaluated with TUNEL method. Furthermore, effects of TMZ on colony formation and invasion were investigated in this study. It was observed that TMZ in SH-SY5Y cell line caused a significant decrease in the gene expressions of URG4/URGCP , CCND1, CCND2, CDK4, and BCL2. According to TUNEL assay results, TMZ markedly induced apoptosis in SH-SY5Y cell line. It was found that TMZ in SH-SY5Y cell line suppressed invasion and colony formation using matrigel invasion chamber and colony formation assay, respectively. To conclude, it is thought that TMZ demonstrates anticarcinogenesis activity by affecting cell cycle arrest, apoptosis, invasion, and colony formation on SH-SY5Y cells. TMZ may be an effective agent for treatment of neuroblastoma as a single or in combination with other drugs. Keywords Neuroblastoma . SH-SY5Y cell . Temozolamide . URG4/URGCP Abbreviations T-ALL T-acute lymphocytic leukemia CDK Cyclin-dependent kinase CNS Central nervous system tumors DMSO Dimethylsulfoxide NB Neuroblastoma TMZ Temozolomide URG4 Upregulated gene 4 URG4CP Upregulator of cell proliferation XTT (2-Methoxy-4-nitro-5-sulfophenyl)-2H- tetrazolium-5-carboxanilide TMZ Temozolomide TUNEL Mediated deoxyuridine triphosphate (dUTP)-digoxigenin nick-end labeling Introduction Neuroblastoma (NB) is an embryonal tumor that is derived from neural cells. NB is the most common extracranial solid tumor of early childhood neoplasm, accounting for approxi- mately 15 % of all pediatric cancer deaths [1, 2]. NB is a highly heterogeneous disease both biologically and clinically; therefore, treatment of NB is applied depending on the stage of the disease, age, and biological prognostic factors [1–3]. In view of these cases, new treatment strategies are needed for neuroblastoma. Temozolomide (TMZ; 3,4-dihydro-3-methyl-4- oxoimidazole) is a DNA-alkylating agent from the Highlights 1. TMZ is inhibiting cell proliferation in SH-SY5Y neuro- blastoma cells by inducing cell cycle arrest via CCND1, CCND2, CDK4, and URG4/URGCP gene expression changes. 2. TMZ is stimulating apoptotic mechanisms in SH-SY5Y. 3. First mechanisms of TMZ and URG4/URGCP relationship in neuro- blastoma cells were presented in this study. * Yavuz Dodurga yavuzdodurga@gmail.com 1 Department of Neurosurgery, Pamukkale University School of Medicine, Denizli, Turkey 2 Department of Medical Biology, Pamukkale University School of Medicine, Denizli, Turkey 3 Department of Medical Biology, Ege University School of Medicine, Izmir, Turkey 4 Department of Forensic Medicine, Ankara University School of Medicine, Ankara, Turkey Tumor Biol. DOI 10.1007/s13277-015-3373-7