Straub Bernd, Müller Markus, Krause Hans, Schrader Mark, Miller Kurt
Department of Urology, Universitätsklinikum Benjamin-Franklin, Freie Universität Berlin, Berlin, Germany.
Oncology. 2003;65 Suppl 1:12-7. doi: 10.1159/000072486.
A great number of studies have failed thus far to demonstrate that the presence of PSA-expressing tumor cells in the blood of prostate cancer (PC) patients is a highly sensitive prognostic marker, particularly after radical prostatectomy (RPX). These studies have only relied on qualitative or semiquantitative detection techniques, however. We report our initial experience in testing real-time RT-PCR for the detection of PSA mRNA using a quantitative online PCR system, the LightCycler(TM), and sequence-specific oligonucleotide hybridization probes.
Blood samples were obtained before and after surgery from 129 patients undergoing RPX for localized PC and from 19 patients undergoing transurethral resection of the prostate for benign prostatic hyperplasia (BPH). Quantitative RT-PCR for the detection PSA mRNA was performed using the LightCycler system with RNA Amplification Kit Hybridization Probes and sequence-specific oligonucleotide hybridization probes.
PSA mRNA was detected by the LightCycler in 28 patients (39%) with pT2 tumors, in 22 patients (38%) with >pT2 tumors, but in only 3 patients (16%) with BPH. The mean values of the LNCaP cell equivalents were higher in >pT2 patients than in pT2 patients (37 x 10(3) and 104 x 10(3)) or BPH patients (7.1 x 10(3) and 4.8 x 10(3)) both preoperatively (333 x 10(3)/ml blood) and postoperatively (545 x 10(3)).
Real-time RT-PCR with the LightCycler appears to be a promising method for the preoperative detection of circulating LNCaP tumor cells in PC as reflected by PSA mRNA. Considering the low detection rates in BPH patients, the method may also be suitable for patient monitoring after RPX and could thus play an important role in deciding on early radiotherapy or even hormone ablation therapy. Additional long-term follow-up will have to show whether patients with high expression of PSA mRNA actually have an increased risk or recurrence and whether the method is suitable as well to detect progression.
迄今为止，大量研究未能证明前列腺癌（PC）患者血液中表达前列腺特异性抗原（PSA）的肿瘤细胞是一种高度敏感的预后标志物，尤其是在根治性前列腺切除术（RPX）之后。然而，这些研究仅依赖于定性或半定量检测技术。我们报告了使用定量在线PCR系统LightCycler™和序列特异性寡核苷酸杂交探针检测PSA mRNA的实时逆转录聚合酶链反应（RT-PCR）的初步经验。
从129例因局限性PC接受RPX的患者以及19例因良性前列腺增生（BPH）接受经尿道前列腺切除术的患者手术前后采集血样。使用带有RNA扩增试剂盒杂交探针和序列特异性寡核苷酸杂交探针的LightCycler系统进行检测PSA mRNA的定量RT-PCR。
LightCycler在28例（39%）pT2期肿瘤患者、22例（38%）>pT2期肿瘤患者中检测到PSA mRNA，但在仅3例（16%）BPH患者中检测到。在术前（333×10³/ml血液）和术后（545×10³），>pT2期患者的LNCaP细胞当量平均值均高于pT2期患者（37×10³和104×10³）或BPH患者（7.1×10³和4.8×10³）。
如PSA mRNA所反映的，使用LightCycler进行实时RT-PCR似乎是术前检测PC中循环LNCaP肿瘤细胞的一种有前景的方法。考虑到BPH患者中的低检测率，该方法也可能适用于RPX后的患者监测，因此在决定早期放疗甚至激素消融治疗方面可能发挥重要作用。额外的长期随访将必须表明PSA mRNA高表达的患者是否实际具有增加的风险或复发，以及该方法是否也适合检测疾病进展。
