CLINICS 2011;66(7):1143-1147 CLINICAL SCIENCE DOI:10.1590/S1807-59322011000700004 Tgf-b1 expression as a biomarker of poor prognosis in prostate cancer Sabrina Thalita dos Reis,I,II Jose´ Pontes-Ju´ nior,I,II Alberto Azoubel Antunes,I,II Juliana Moreira de Sousa- Canavez,III Daniel Kanda Abe,II Jose´ Arnaldo Shiomi da Cruz,I Marcos Francisco Dall’Oglio,II Alexandre Crippa,II Carlo Camargo Passerotti,I Leopoldo A Ribeiro-Filho,I Nayara Izabel Viana,I Miguel Srougi,I Ka´ tia Ramos Moreira LeiteI I Laboratory of Medical Investigation (LIM55), Urology Department, Faculdade de Medicina da Universidade de S a˜o Paulo, S a˜o Paulo, Brazil. II Uro- Oncology Group, Urology Department, Faculdade de Medicina da Universidade de S a˜o Paulo, S a˜o Paulo, Brazil. III Genoa Biotechnology SA, S a˜o Paulo, Brazil. OBJECTIVE: To evaluate the correlation between transforming growth factor beta (TGF-b1) expression and prognosis in prostate cancer. PATIENTS AND METHODS: TGF-b1 expression levels were analyzed using the quantitative real-time polymerase chain reaction to amplify RNA that had been isolated from fresh-frozen malignant and benign tissue specimens collected from 89 patients who had clinically localized prostate cancer and had been treated with radical prostatectomy. The control group consisted of 11 patients with benign prostate hyperplasia. The expression levels of TGF-b1 were compared between the groups in terms of Gleason scores, pathological staging, and prostate-specific antigen serum levels. RESULTS: In the majority of the tumor samples, TGF-b1 was underexpressed 67.0% of PCa patients. The same expression pattern was identified in benign tissues of patients with prostate cancer. Although most cases exhibited underexpression of TGF-b1, a higher expression level was found in patients with Gleason scores $7 when compared to patients with Gleason scores ,7 (p = 0.002). Among the 26 cases of TGF-b1 overexpression, 92.3% had poor prognostic features. CONCLUSIONS: TGF-b1 was underexpressed in prostate cancers; however, higher expression was observed in tumors with higher Gleason scores, which suggests that TGF-b1 expression may be a useful prognostic marker for prostate cancer. Further studies of clinical specimens are needed to clarify the role of TGF-b1 in prostate carcinogenesis. KEYWORDS: Prostate cancer; Prognosis; Molecular markers; TGF-b. Reis ST, Pontes-Ju´ nior J, Antunes AA, Sousa-Canavez JM, Abe DK, Cruz JAS, et al. Tgf-b1 expression as a biomarker of poor prognosis in prostate cancer. Clinics. 2011;66(7):1143-1147. Received for publication on January 14, 2011; First review completed on February 11, 2011; Accepted for publication on March 13, 2011 E-mail: sasareis@gmail.com Tel.: 55 11 3061-7000 INTRODUCTION Prostate cancer (PCa) is the most common male malig- nancy and is the second-highest cause of death in many countries, including Brazil.1 Pathological staging, Gleason scores, and prostate-specific antigen (PSA) serum levels are the most reliable prognostic factors; however, even when combined, they do not perfectly identify patients who are at risk of progression.2 Therefore, research has been aimed at identifying molecular markers that can predict PCa predis- position and progression. Copyright 2011 CLINICS – This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Transforming growth factor beta (TGF-b) is the proto- typical member of a superfamily that includes more than 25 members, including inhibin, bone morphogenetic protein, and M u¨llerian inhibiting substance. The TGF-b subfamily contains five members named TGF-b1 through b5. TGF-b1, -b2, and -b3 have been identified in mammals.3,4 Although TGF-b is a pleiotropic growth factor, it inhibits growth in most cell types, especially cells of epithelial lineage. TGF-b also inhibits prostatic epithelial cell proliferation and induces apoptosis.5,6 In addition to its numerous effects on cell proliferation, phenotype, and differentiation,7 TGF-b is an important transcriptional regulator of extracellular matrix components. Malignant transformation is characterized by multiple genetic mutations that confer a growth advantage to transformed cells compared with benign cells. The devel- opment of prostate cancer follows this paradigm. TGF-b is involved in two critical events that are consistently 1143