PCA3 and TMPRSS2-ERG gene fusions as diagnostic biomarkers for prostate cancer

The incidence of prostate cancer （PCa） is rising steadily among males in many countries. Serum prostate-specific antigen （PSA） is widely applied to clinical diagnosis and screening of PCa. However, the so-called grey area of PSA levels 4.0-10.0 ng/mL has a low specificity of 25-40% resulting in a high rate of negative biopsy and overtreatment. So in order to treat PCa patients in early stage, there is an urgent need for new biomarkers in PCa diagnosis. The PCA3 gene, a non-coding RNA （ncRNA） that is highly expressed in prostate cancer （PCa） cells, has been identified as a molecular biomarkers to detect PCa, of which PCA3 has already under clinical application. PCA3 is strongly overexpressed in malignant prostate tissue compared to benign or normal adjacent one. Newly, PCA3 is considered to be a promising biomarker in clinical diagnosis and targeted therapy. The diagnostic significance of PCA3, however, is awaiting further researches. Moreover, it has been demonstrated recently that TMPRSS2-ERG gene fusion is identified as the predominant genetic change in patients diagnosed with PCa. Recent study revealed that combination of the PC43 and TMPRSS2-ERG gene fusion test optimizes PCa detection compared with that of single biomarker, which would lead to a considerable reduction of the number of prostate biopsies. In this review, we focused on the potential use of PCA3 and TMPRSS2-ERG gene fusion detection in the diagnosis of PCa.

环巴胺对人前列腺癌LNCaP细胞增殖和凋亡作用及对PCA3基因表达的影响

目的:探讨环巴胺对人前列腺癌LNCaP细胞增殖和凋亡的作用及对PCA3基因表达的影响。方法:不同浓度环巴胺(1、5、10、15μmol/L)干预LNCaP细胞,以只加入RPMI 1640培养液为空白对照组,分别在不同作用时间(24、48、72h),用MTT法检测其对细胞增殖的抑制、流式细胞术观察细胞凋亡率变化、Hoechst染色观察凋亡细胞形态变化、实时荧光定量逆转录聚合酶链反应(FQ-RT-PCR)观察对PCA3基因表达的影响。结果:5、10、15μmol/L环巴胺对LNCaP细胞增殖均有显著抑制作用,与空白对照组相比差异有显著性(P<0.01),10μmol/L组于48h达到半数抑制量(IC50);10、15μmol/L组24、48、72hLNCaP细胞的凋亡率分别为37.21%、57.38%、57.98%和21.16%、71.31%、72.90%,与空白对照组相比差异均有显著性(P<0.01)。随着环巴胺浓度增大和作用时间的延长,LNCaP细胞凋亡显著增加。PCA3基因的表达随着环巴胺浓度的上升呈现明显的递减趋势,较空白对照组显著降低(P<0.01)。浓度为10μmol/L时,不同作用时间PCA3基因的表达均极低。结论:环巴胺浓度为10、15μmol/L作用48、72h时能够明显抑制LNCaP细胞的增殖,诱导细胞凋亡,并显著下调LNCaP细胞PCA3基因的表达。

尿液中PCA3评分对前列腺癌早期诊断的临床意义

目的:探讨不同尿液中前列腺癌基因3(PCA3)评分的截断值对可疑前列腺癌患者诊断的应用价值。方法:纳入123例因血清总前列腺特异性抗原(t-PSA)升高和(或)直肠指诊(DRE)异常住院的患者,采集前列腺按摩后的初始尿液标本,使用实时定量PCR检测尿沉渣中PSA及PCA3 mRNA的表达,测定穿刺前尿样PCA3的评分。结合穿刺的病理结果分析不同尿PCA3评分的截断值对诊断前列腺癌的敏感性和特异性(阳性预测和阴性预测)。结果:经穿刺病理结果证实前列腺癌32例,前列腺良性增生91例。当取PCA3评分截断值为35时,可避免52.7%(48例)的患者进行不必要的穿刺,8.8%(8例)的患者被漏诊(被漏诊的患者均是低危前列腺癌);当取PCA3评分截断值为50时,可避免72.5%(66例)的患者进行不必要的穿刺,但13.2%(12例)的患者被漏诊,且2例(16.7%)是中高危前列腺癌。结论:检测可疑前列腺癌患者尿液中PCA3评分可减少不必要的穿刺,且取截断值为35时可获得较高的诊断价值。

PCA3特异性启动TRAIL诱导前列腺癌PC3细胞凋亡效应研究

目的研究PCA3启动子调控TRAIL/TNFSF10的真核表达载体在体外特异性诱导前列腺癌PC3细胞凋亡效应。方法已构建好pHBAd-PCA3-TRAIL重组质粒及对照组质粒转染前列腺癌PC3细胞及对照组细胞,MTT法及流式细胞术检测各组凋亡效应,RealTimePCR及Westernblot检测TRAIL表达情况及DR5、caspase-8水平。结果各组质粒成功转染靶细胞,体外实验可观察到实验组细胞活力明显低于各对照组,差距有统计学意义;进一步检测显示仅实验组导入的TRAIL基因可特异性表达且DR5、caspase-8水平明显升高。结论pHBAd-PCA3-TRAIL在前列腺癌PC3细胞中特异性表达TRAIL,并激活DR5、caspase-8相关通路在体外对前列腺癌PC3细胞表现出特异性诱导凋亡作用,为后续前列腺癌治疗研究中基于PCA3启动子相关探索打下基础。

Function of PCA3 in prostate tissue and clinical research progress on developing a PCA3 score

Prostate cancer gene 3 （PCA3, also known as DD3） is a new biomarker that could improve the accuracy of prostate cancer diagnosis. It is a great biomarker with fairly high specificity and sensitivity. The incidence of prostate cancer is rising steadily in most countries. The commonly used prostate-specific antigen （PSA） test once gave people hope for early diagnosis of prostate cancer. However, the low specificity of the PSA test has resulted in a large number of unnecessary biopsies and overtreatment. During the past decade, many new prostate cancer biomarkers have been found. Among these, PCA3 is the most promising. Due to its great performance in distinguishing prostate cancer from other prostate conditions, PCA3 could likely be applied for early diagnosis of prostate cancer, patient follow-up, prognosis prediction, and targeted therapy. After years of research, we have obtained some knowledge about the sequence of PCA3 gene. We have also determined the relationship between PCA3 and the proliferation of prostate cancer cells and learned some information about how PCA3 affects tumor-related genes and proteins. A PCA3 score has been created, and it has been used in a variety of studies. Some researchers have even applied PCA3 to targeted therapy and obtained a good effect in vitro. This review describes the current state of research, and explores the future prospects for PCA3.

前列腺癌实验室诊断的最新进展

用于实验室检查前列腺癌(prostate cancer,PCa)的前列腺特异性抗原(prostate-specific antigen,PSA)已无法满足临床的需求,目前急需新型的前列腺癌标志物来诊断和检测前列腺癌的发生、发展和预后。随着研究的深入众多,新型前列腺癌标志物在不同方面都体现了各自的优势,同时又存在其不足。该文通过广泛查阅最新的资料,比较各个指标的诊断效能、优缺点及目前临床应用的情况,探讨前列腺癌实验室诊断的最新进展,寻找能够加强前列腺癌的诊断效能的新方法,以期为患者提供更加高效的治疗手段。

PCA3(DD3)基因多态性与前列腺癌风险关系的研究

目的:探讨PCA3基因多态性与前列腺癌遗传易感性的关系。方法:采用PCR和基因片段直接测序方法,分别检测41例前列腺癌(PCa)患者和40例良性前列腺增生(BPH)患者的PCA3外显子区域的SNP变异情况,分析PCA3基因多态性与PCa的相关性。结果:PCA3基因外显子2区域存在1个SNP位点(A164C),基因型分别为AA型、AC型、CC型;Logistic回归分析显示,AC、CC及AC+CC基因型是PCa的危险因子(OR值=6.171,95%CI=1.877-20.286;OR值=5.400,95%CI 1.421-20.518;OR值=5.891,95%CI=1.915-18.124),等位基因C是PCa的危险因子(OR值=2.353,95%CI=1.252-4.421)。结论:PCA3基因外显子2 SNP A164C多态性与PCa的发病风险高度相关,携带等位基因C的基因型是PCa的遗传危险因素。

uPCA3mRNA及PCA3mRNA/D定量检测对PSA灰区前列腺癌诊断的临床研究

目的：研究前列腺按摩后尿液中PCA3mRNA及PCA3mRNA密度的定量检测在前列腺特异性抗原（PSA）灰区前列腺癌（PCa）临床诊断中的应用价值。方法：选择sPSA在4～10ng／ml的BPH或PCa患者200例，收集其前列腺按摩后尿液，离心取细胞沉淀物，提取总RNA，用实时荧光定譬RT—PCR方法检测PSAmRNA、PCA3mRNA的含量，以PSAmRNA来校正尿液中的前列腺癌细胞。以PCA3mRNA／PSAmRNA表示PCA3mRNA的含量，经直肠B超测定前列腺体积，计算PSAD和PCA3mRNA密度（PCA3mRNA／I））。以穿刺活检或术后病理检查结果为金标准，用ROC曲线对PCA3mRNA及PCA3mRNA／D诊断PSA灰区PCa的性能进行评价。结果：PCa组的tPSA、PSAD均较BPH组升高fP〈O．05或0．01）。PCa组PCA3mRNA（P=0．009）含量及PCA3mRNA／D比值（P=0．005）均高于BPH组；以2．01为截断值时．尿PCA3mRNA／D比值诊断PCa的ROC曲线下面积（AUC）为0．903（95％CI：0．790～0．869），其诊断PCa的敏感度和特异度分别为93．3％和66．7％。尿PCA3mRNA／psAmRNA比值诊断PCa的ROC曲线下面积（AUC）为0．841（95％CI：0．666～0．997），以0．27为截断值时，其诊断PCa的敏感度和特异度为86．5％和77．5％。结论：PCA3mRNA含量和PCA3mRNA／D两个指标定量检测，可以显著提高检出PSA灰区PCa的敏感度，可用于早期PCa的诊断。其中PCA3mRNA／D具有更好的诊断效能。

PCA3基因作为前列腺癌特异性标记物的研究进展

随着人口的老龄化和诊断水平的提高，前列腺癌的发病率和检出率越来越高，迫切需要一种对前列腺癌特异性和敏感性较高的标记物提高其早期检出率，PCA3的发现为前列腺癌的早期诊断带来了新的希望。