PCA3 gene expression in prostate cancer tissue in a Chinese population: Quantification by real-time FQ-RT-PCR based on exon 3 of PCA3 Zhihua Tao a,b , Mo Shen b , Yanbo Zheng b , Xiaolu Mao b , Zhanguo Chen b , Yibing Yin a, ⁎, Kaiyuan Yu c , Zhiliang Weng d , Hui Xie d , Chengdi Li d , Xiuling Wu e , Yuanping Hu f , Xiaohua Zhang g , Ouchen Wang g , Qitong Song h , Zhixian Yu d a Department of Medical Laboratory, Chongqing Medical University, Chongqing, PR China b Department of Medical Laboratory, The First Affiliated Hospital of Wenzhou Medical College, Zhejiang, PR China c Department of Urology, The Second Affiliated Hospital of Wenzhou Medical College, Zhejiang, PR China d Department of Urology, The First Affiliated Hospital of Wenzhou Medical College, Zhejiang, PR China e Department of Pathology, The First Affiliated Hospital of Wenzhou Medical College, Zhejiang, PR China f Department of B-Ultrasound, The First Affiliated Hospital of Wenzhou Medical College, Zhejiang, PR China g Department of Tumor Surgery, The First Affiliated Hospital of Wenzhou Medical College, Zhejiang, PR China h Department of General surgery, The First Affiliated Hospital of Wenzhou Medical College, Zhejiang, PR China abstract article info Article history: Received 22 July 2009 and in revised form 27 December 2009 Available online 28 January 2010 Keywords: PCA3 (DD3) Prostate cancer Real-time FQ-RT-PCR Prostate cancer (PCa) is the second most common cancer in men, and its incidence is still increasing. PCA3 is the most prostate cancer specific biomarker. Here we confirmed that both exon 3 and exon 4 are in the prostate- specific region of the PCA3 gene, and established the methodology of real-time fluorescent quantitative RT-PCR (FQ-RT-PCR) detecting PCA3 mRNA with primer spanning exons 1 and 3, and evaluated its clinical utility in a Chinese population. What disclosed that PCA3 mRNA is prostate cancer specific and shows increased expression in prostate cancer. It could be a reliable molecular marker in prostate cancer diagnosis. Exon 3- based real-time FQ-RT-PCR may prove useful in prostate cancer diagnosis, given that the associated primer would span only exons 1 and 3, relative to other models spanning exons 1 to 4. A shorter amplicon would not only enhance the efficiency of real-time FQ-RT-PCR, but may also simplify the quantification of PCA3 mRNA. © 2010 Published by Elsevier Inc. Introduction With a worldwide incidence of 25.3 per 100,000 (Jemal et al., 2008), prostate cancer (PCa) is the second most common cancer in men, and its incidence is still increasing. Indeed, in recent decades, prostate cancer is being diagnosed more frequently in China. Fortunately, there were several effective treatments for localized prostate cancer, such as radical surgery and radiation therapy (Paulson et al., 1990; Pound et al., 1997; Walsh et al., 1994; Zincke et al., 1994). However, once metastases develop, the prognosis is poor (Epstein et al., 1993; Lu-Yao et al., 1993). Hence, early diagnosis of prostate cancer is of paramount importance for successful cancer therapy. Molecular markers for the early detection of prostate cancer offer hope for improving outcomes. Over the past 20 years, serum prostate- specific antigen (PSA) has been used for the diagnosis of prostate cancer and for monitoring patients after therapy (Pannek and Partin, 1997). Although the serum PSA is highly sensitive, it lacks adequate specificity. For instance, serum PSA also increases in the setting of benign prostatic hyperplasia (BPH), prostatitis and other nonmalignant phenomena. Therefore, researchers continue to seek a more specific tumor marker. Other specific markers have been discovered, including prostate- specific membrane antigen (PSMA), which is over-expressed in prostate cancer compared with normal prostate and BPH (Murphy et al., 1996). Additionally, other over-expressed markers identified in recent years include telomerase (Kallakury et al., 1997; Scates et al., 1997), TMPRSS2 (Lin et al., 1999), PDEF (Oettgen et al., 2000), Hepsin (Magee et al., 2001), δ-catenin (Burger et al., 2002), α-methylacyl-coenzyme A racemase (AMACR) (Zhou et al., 2002) and prostate cancer antigen 3 (PCA3, formerly called DD3) (Bussemakers et al., 1999; de Kok et al., 2002; Schiffer, 2007; Hessels et al., 2009; Väänänen et al., 2008). So far, of the molecular markers described, PCA3 is the most specific for prostate cancer. In 1999, Bussemakers et al. identified the PCA3 gene using differential display analysis. The structure of the PCA3 transcription unit showed that the PCA3 gene consisted of four exons. Exon 2 was only present in 5% of the cDNA clones analyzed and was often skipped by alternative splicing. Alternative polyadenylation occurred at three different positions in exon 4 (4a, 4b and 4c). Exons 1, 3 and 4a were present in all three of the different transcripts, and the most frequently found cDNA clone (60% of all cDNA clones analyzed) contains exons 1, 3, 4a and 4b. RT-PCR analysis Experimental and Molecular Pathology 89 (2010) 58–62 ⁎ Corresponding author. Department of Medical Laboratory, Chongqing Medical University, 1 Yi Xue Yuan Road, Chongqing 400016, PR China. Fax: +86 023 68485041. E-mail address: yibing@21cn.com (Y. Yin). 0014-4800/$ – see front matter © 2010 Published by Elsevier Inc. doi:10.1016/j.yexmp.2010.01.008 Contents lists available at ScienceDirect Experimental and Molecular Pathology journal homepage: www.elsevier.com/locate/yexmp