UNCORRECTED PROOF 1 2 Polo-like kinase and survivin are esophageal 3 tumor-specific promoters q,qq 4 Fumiaki Sato a,b,c, * , John M. Abraham a , Jing Yin a , Takatsugu Kan a , Tetsuo Ito a , 5 Yuriko Mori a,b , James P. Hamilton a , Zhe Jin a , Yulan Cheng a , Bogdan Paun a , 6 Agnes Berki a , Suna Wang a , Yutaka Shimada d , Stephen J. Meltzer a,b,c,e 7 a Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA 8 b University of Maryland Marlene and Stewart Greenebaum Cancer Center, Baltimore, MD 21201, USA 9 c Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA 10 d Department of Surgery and Surgical Basic Science, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan 11 e Baltimore VA Medical Center, Baltimore, MD 21201, USA 12 Received 30 January 2006 13 14 Abstract 15 For developing successful cancer gene therapy strategies, tumor-specific gene delivery is essential. In this study, we used esophageal 16 cancer (EC) cells to identify and evaluate esophageal tumor-specific gene promoters. Four genes (polo-like kinase-1/PLK, survivin/ 17 BIRC5, karyopherin a 2/KPNA2, and pituitary tumor transforming gene protein 1/PTTG1) were identified by a microarray analysis 18 as highly expressed in EC cell lines vs. five normal organ tissues (liver, lung, kidney, brain, and heart). By quantitative RT-PCR, the 19 average mRNA expression levels of these four genes in 20 primary ECs were 2.7-fold (PLK), 6.1-fold (survivin), 2.6-fold (KPNA2), 20 and 2.4-fold (PTTG1) higher than that of each gene in 24 different normal organs. By dual luciferase assay, the promoter activity of 21 PLK and survivin in EC cell lines was 18.9-fold and 28.5-fold higher, respectively, than in normal lung and renal cells. The promoters 22 of PLK and survivin could be useful tools for developing EC-specific gene therapy vectors. 23 Ó 2006 Elsevier Inc. All rights reserved. 24 Keywords: Esophageal cancer; Gene therapy; Tumor-specific promoter; Microarray 25 26 Esophageal cancer (EC) has a very aggressive behavior 27 and tends to recur after surgery and to spread systematical- 28 ly, despite recent surgical and chemo-radiotherapeutic 29 advances; moreover, EC ranks as the eighth most common 30 malignancy and the sixth most frequent cause of cancer 31 death worldwide [1]. Survival of esophageal cancer patients 32 remains poor, being approximately 10% for squamous cell 33 carcinoma (ESCC) and 20% for adenocarcinoma (EAC) 34 [2]. Thus, other therapeutic methods with the capability 35 of systematic application are needed. Gene therapy is one 36 such therapeutic approach. 37 At the experimental level, a number of gene therapy 38 approaches have been applied to esophageal cancer, and 39 results have been promising. Gene transfer of p16 [3], p53 40 [4], p21 [5], and p14 [6], and gene knock-down of cyclin 41 D1 [7], c-myc [8], and VEGF [9] induced cell growth 0006-291X/$ - see front matter Ó 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.bbrc.2006.01.177 q This article was supported by the American Gastroenterological Association/June and Donald O. Castell, MD, Clinical Esophageal Research Award, and USPHS Grants CA85069, CA01808, CA95323, CA98450, CA77057, the Veterans Affairs Office of Medical Research, and a Grant-in-Aid from the Japanese Ministry of Education, Science and Culture, Sports, Science and Technology (Grants 12307026, 12470259, and 14370385). qq Abbreviations: EC, esophageal cancer; ESCC, esophageal squamous cell carcinoma; EAC, esophageal adenocarcinoma; RT-PCR, reverse- transcriptase polymerase chain reaction; qRT-PCR, quantitative reverse- transcriptase polymerase chain reaction; PLK, polo-like kinase; PTTG1, pituitary tumor transforming gene 1; KPNA, karyopherin a 2; SAM, significance analysis of microarray; TNF, tumor necrosis factor; TSP, tumor-specific promoter; HNBEC, human bronchial epithelial cells; HNRCEC, human normal renal cortical epithelial cells. * Corresponding author. Fax: +1 410 706 1099. E-mail address: fsato@som.umaryland.edu (F. Sato). www.elsevier.com/locate/ybbrc Biochemical and Biophysical Research Communications xxx (2006) xxx–xxx BBRC YBBRC 15748 No. of Pages 7, Model 5+ 8 February 2006 Disk Used Sethu (CE) / Murali (TE) ARTICLE IN PRESS