Abstract LB-91: Transcriptome analysis of esophageal squamous cell carcinoma by SAGE identifies a new biomarker, NRD1

Abstract

Abstract Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies worldwide. Because most ESCC is diagnosed at advanced stages, the overall 5-year survival rate of ESCC still remains low in spite of the use of various treatment modalities. Therefore, identification of new diagnostic markers and therapeutic targets for ESCC is important. Serial Analysis of Gene Expression (SAGE) is one of the common comprehensive methods to analyze transcript expression levels, and enables the quantitative and simultaneous analysis of a large number of transcripts. To identify potential diagnostic markers and therapeutic targets for ESCC, the SAGE library was generated from one ESCC sample. A total of 14,430 tags were generated, including 5,765 that were unique. By comparing SAGE tags from the ESCC sample with those from normal human squamous esophagus, several genes that is upregulated in ESCC compared with normal squamous esophagus in ESCC were identified. Among these, we focused on the nardilysin (N-arginine dibasic convertase, NRD1) gene. NRD1 has been reported to be associated with ectodomein shedding of TNF-α through activation of ADAM proteases. There is only one report in the literature mentioning the association of NRD1 with cancer (breast cancer), however, there is no report that links expression of NRD1 and ESCC. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis showed a high level of NRD1 expression in three of five esophageal cancer cell lines and seven of 14 ESCC samples, but not in 14 normal systemic tissues. Western blot analysis also showed upregulation of NRD1 protein in total five esophageal cancer cell lines. Immunohistochemical analysis revealed expression of NRD1 in cytoplasm of 43 out of 109 ESCC cases (39%), as well as heart, skeletal muscle, and testis in agreement with previous reports. In clinicopathological analysis, expression of NRD1 correlated with the advanced T grade, N grade and tumor stage, and was an independent predictor of survival in patients with ESCC. Knockdown of NRD1 in TE5 cells inhibited cell invasion ability. Furthermore, qRT-PCR analysis showed a reduction of matrix metalloproteinase-2 (MMP-2) expression in NRD1 knocked down cells. In conclusion, NRD1 is an independent predictor of survival, and contribute to cell invasion through regulation of MMP-2 in ESCC. NRD1 could be a novel diagnostic and therapeutic target for ESCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-91. doi:1538-7445.AM2012-LB-91