Brief Article
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World J Clin Urol. Jul 24, 2013; 2(2): 10-14
Published online Jul 24, 2013. doi: 10.5410/wjcu.v2.i2.10
Potential of metastin and metastin receptor as biomarkers for urological cancers
Sunao Shoji, Haruhiro Sato, Tetsuro Tomonaga, Hakushi Kim, Shuichi Soeda, Mayura Nakano, Toyoaki Uchida, Toshiro Terachi, Koichi Takeya
Sunao Shoji, Tetsuro Tomonaga, Hakushi Kim, Toyoaki Uchida, Department of Urology, Tokai University Hachioji Hospital, Hachioji, Tokyo 192-0032, Japan
Haruhiro Sato, Department of Internal Medicine, Tokai University School of Medicine, Isehara, Kanagawa 259-1193, Japan
Shuichi Soeda, Department of Urology, Tokai University Oiso Hospital, Naka-gun, Kanagawa 259-0198, Japan
Mayura Nakano, Department of Urology, Numazu City Hospital, Numazu, Shizuoka 410-0302, Japan
Toshiro Terachi, Department of Urology, Tokai University School of Medicine, Isehara, Kanagawa 259-1193, Japan
Koichi Takeya, Department of Natural Products and Medical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0355, Japan
Author contributions: Shoji S designed research and performed research; Shoji S, Sato H, Tomonaga T, Kim H, Soeda S, Nakano M, Uchida T, Terachi T and Takeya K analyzed data; Shoji S wrote the paper.
Correspondence to: Sunao Shoji, MD, PhD, Department of Urology, Tokai University Hachioji Hospital, 1838 Ishikawa-machi, Hachioji, Tokyo 192-0032, Japan. sunashoj@mail.goo.ne.jp
Telephone: +81-42-6391111 Fax: +81-42-6391111
Received: April 15, 2013
Revised: May 31, 2013
Accepted: June 8, 2013
Published online: July 24, 2013
Processing time: 101 Days and 4.9 Hours
Abstract

AIM: To investigate the current state of the research of metastin and metastin receptor in the urological cancer field.

METHODS: For analyzing the value of metastin and metastin receptor as molecular biomarkers for the patients with urological cancer, MEDLINE database searches were performed using these terms: metastin, KISS1, kisspeptin, renal (cell) carcinoma (RCC), kidney cancer or urothelial cancer or bladder cancer or prostate cancer or testicular cancer (tumor). Since the articles were evaluated by the validity of the articles based on plausibility, credibility, and evidence levels, the articles were graded according to their level of evidence, using the grading system defined by the Oxford Centre for Evidence-based Medicine.

RESULTS: A total of six clinical studies published by individual institutions between 2003 and 2013 were included in this review. The article numbers for each of the evidence levels 2a and 2b were three (50%) and three (50%), respectively. Immunohistochemistry and reverse transcriptase-polymerase chain reaction using tumor tissues were performed to analyze in five articles (83%) and in one article (17%). The value of metastin and/or metastin receptor as molecular biomarkers in clear cell RCC, upper tract urothelial carcinoma, and bladder cancer was evaluated by multivariate analysis. Low expression of metastin receptor in clear cell RCC and low expression of metastin in upper tract urothelial carcinoma were significant risk factors for metastasis, and low metastin expression was an independent prognostic factor in bladder cancer.

CONCLUSION: Metastin and metastin receptor have potential as suitable molecular biomarkers for urological cancers. However, future studies of metastin and metastin receptor should undergo external validation to ensure consistency across different patient series, since individual institutional studies lack generalization.

Keywords: KISS-1; Metastin; Metastin receptor; Metastasis; Renal cell carcinoma; Upper tract urothelial carcinoma; Bladder cancer

Core tip: Metastin and metastin receptor have attracted interest in the field of cancer because of their novelty and potential to inhibit cancer metastasis. Furthermore, they have potential as suitable molecular biomarkers for urological cancers. However, the results of all of the studies analyzed in this review were retrospectively obtained. Therefore, future studies of metastin and metastin receptor should undergo external validation to ensure consistency across different patient series, since individual institutional studies lack generalization.