Rapid and quantitative detection of human septin family Bradeion as a practical diagnostic method of colorectal and urologic cancers

M Tanaka MD PhD^a, T Tanaka MD PhD^a, S Matsuzaki MSc^c, Y Seto MSc^d, T Matsuda MSc^a, K Komori MSc^a, J Itoh PhD^b, H Kijima MD PhD^b, K Tamai PhD^e, M Shibayama MSc^e, Y Hashimoto MD PhD^f, H Nakazawa MD PhD^f, H Toma MD PhD^f

^aNational Institute of Advanced Industrial Science and Technology, Ibaraki, Japan, ^bTokai University School of Medicine, Kanagawa, Japan, ^cNTC/Nippn Technocluster, Inc, Tokyo, Japan, ^dNippon Flour Mills Co, Ltd, Tokyo, Japan, ^eR&D Division, CycLex Co. Ltd, Nagano, Japan, ^fTokyo Women's Medical University, Tokyo, Japan

AIM: Malignant tumor progression is a complex and multi-gene event which can not be easily detected or predicted. The detection of malignant cells using marker genes is hampered by the fact that these markers are only expressed by certain malignancies or lack sensitivity and/or specificity. We have reported a human septin family gene Bradeion, which shows strong cancer-specific expression in colorectal and urologic cancers as a result of carcinogenesis [1-3]. Methods: Diagnostic efficacy and validity of Bradeion gene expression were tested by two independent systems, one is a protein detection method using monoclonal antibody based immuno-chromatographic membrane strip tests (a nitrocellulose test strip assay), and another is a gene expression detection method, quantitative RT-PCR. The technology has been established using Bradeion fusion proteins, in vitro culticated human cancer cell lines, and also patientsユ test samples with controls. Results: Bradeion test strip by combination with two monoclonal antibodies are valid for the detection of 0.1 ng/ml Bradeion, and successfully applied for patient urine samples with no false-positive results. Positive detection rates were 74.7% in prostate cancer, 74.7% in renal cell carcinoma, and 86% in bladder cancer in 15 to 30 minutes. Quantitative RT-PCR resulted in significantly high copy numbers of 0.4 - 3.0 x 105 per オg total RNA in patientsユ tissue samples, whereas those from normal tissue or other cancers found negative. Conclusions: The present study introduces the practical diagnostic methods using a disease-specific molecular marker, which provides safe, economical, and rapid clinical screening of cancer.

Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Nice, France; February 7 - 10, 2004; in poster session 893 (Molecular pathology).