CD31, EDNRB and TSPAN7 are promising prognostic markers in clear-cell renal cell carcinoma revealed by genome-wide expression analyses of primary tumors and metastases Daniela Wuttig 1 , Stefan Zastrow 1 , Susanne Fu ¨ssel 1 , Marieta I. Toma 2 , Matthias Meinhardt 2 , Kristin Kalman 1 , Kerstin Junker 3 , Jimsgene Sanjmyatav 3 , Kerstin Boll 4 ,J€ org Hackermu ¨ller 4,5 , Axel Rolle 6 , Marc-Oliver Grimm 1 and Manfred P. Wirth 1 1 Department of Urology, University Hospital Carl Gustav Carus, Dresden, Germany 2 Institute of Pathology, University Hospital Carl Gustav Carus, Dresden, Germany 3 Department of Urology, Friedrich-Schiller-University, Jena, Germany 4 Department of Diagnostics and New Technologies, Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany 5 Young Investigators Group Bioinformatics and Transcriptomics, Department Proteomics, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany 6 Department of Thoracic and Vascular Surgery, Coswig Specialized Hospital, Center for Pneumology, Thoracic and Vascular Surgery, Coswig, Germany Currently used clinicopathological parameters are insufficient for a reliable prediction of metastatic risk and disease-free survival (DFS) of patients with clear-cell renal cell carcinoma (ccRCC). To identify prognostic genes, the expression profiles of primary ccRCC obtained from patients with different DFS — eight synchronously, nine metachronously and seven not metastasized tumors — were determined by genome-wide expression analyses. Synchronously and metachronously metastasized primary ccRCC differed in the expression of 167 genes. Thirty-six of these genes were also differentially expressed in synchronously vs. metachronously developed pulmonary metastases analyzed in a previous study. Because of their DFS-associated deregulation that is concordant in metastases and primary ccRCC, these genes are potentially functionally involved in metastatic tumor growth and are also prognostically useful. A prognostic impact was confirmed for the genes CD31, EDNRB and TSPAN7 at the mRNA level (n 5 86), and for TSPAN7 at the protein level (n 5 106). Patients with a higher gene expression of EDNRB or TSPAN7, or with TSPAN7-positive vessels in both cores investigated on tissue microarrays had a significantly longer DFS and tumor-specific survival (TSS). Patients with a higher CD31 gene expression showed a significantly longer TSS. EDNRB was an independent prognostic marker for the DFS. CD31, EDNRB and TSPAN7 had an independent impact on the TSS. In summary, comparative analysis of primary tumors and metastases is appropriate to identify independent prognostic markers in ccRCC. Gene expression of CD31 and EDNRB, and endothelial TSPAN7 protein level are potentially useful to improve outcome prediction because of their independent prognostic impact. The development of macroscopic metastases is the major cause of tumor-associated deaths. 1,2 Clear-cell renal cell carci- noma (ccRCC), which is the most frequent type of kidney cancer, 3 causes initial or metachronous metastases in about 50% of the patients. 4 The median five-year survival rate of patients with metastatic ccRCC accounts for only 11–20%. 5 The disease-free survival (DFS) until manifest metastases de- velop differs extremely in these patients and results in a very diverse disease outcome. The DFS reflects the dormancy pe- riod that tumor cells can undergo after they have settled in a secondary organ. This latency can persist for many years. 2 It is supposed to be caused by suppressed tumor cell prolifera- tion, inhibited angiogenesis or antitumor immune responses. 6 Currently used clinicopathological parameters are insuffi- cient for a reliable outcome prediction for ccRCC patients. The molecular prognostic markers known to date are not suitable for a routine clinical use. 7 Therefore, new molecular markers are urgently needed to predict individual metastatic risk and DFS of ccRCC patients. Such markers represent the Key words: metastasis, molecular markers, oligonucleotide microarrays, multivariate survival analyses Abbreviations: ccRCC: clear-cell renal cell carcinoma; CT: threshold cycle; CP: crossing point; FDR: false discovery rate; HR: hazard ratio; MVD: microvessel density; n: number of samples; RCC: renal cell carcinoma; TLDA: TaqMan low-density arrays; TMAs: tissue microarrays Additional Supporting Information may be found in the online version of this article Gene lists are available at http://urologie.uniklinikum-dresden.de/ ba_labor_research_download.htm Grant sponsors: Dr. Robert Pfleger Foundation, Ju ¨rgen Manchot Foundation, Medical Faculty of the Dresden University of Technology DOI: 10.1002/ijc.27419 History: Received 7 Feb 2011; Accepted 12 Dec 2011; Online 31 Dec 2011 Correspondence to: Daniela Wuttig, Cancer Genome Research, Division of Molecular Genetics, German Cancer Research Center and National Center for Tumor Diseases, Im Neuenheimer Feld 460, 69120 Heidelberg, Germany, Tel.: þ49(0)6221-565964, Fax: þ49(0)6221 565382, E-mail: d.wuttig@dkfz.de Early Detection and Diagnosis Int. J. Cancer: 131, E693–E704 (2012) V C 2011 UICC International Journal of Cancer IJC