Moreno J G, O'Hara S M, Long J P, Veltri R W, Ning X, Alexander A A, Gomella L G
Department of Urology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Urology. 1997 Apr;49(4):515-20. doi: 10.1016/s0090-4295(97)00016-2.
To determine if transrectal ultrasound-guided (TRUS) prostate biopsy causes dissemination of prostate cells into the circulation as assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) targeted against prostate-specific antigen (PSA) mRNA.
RT-PCR PSA analysis was performed before and after prostatic invasive manipulations in 50 men. The cases consisted of 47 patients with TRUS and 3 with transurethral resection of the prostate (TURP). Peripheral venous blood (8 mL) was drawn before and within 60 minutes after the procedure. Total RNA was extracted from fractionated blood, and RNA/cDNA quality was assured and normalized with beta-actin RT-PCR analysis. The PSA primers hybridize exons 3 and 5, yielding a 254-basepair PCR product. The assay detects one LNCaP cell in a background of 100 million lymphoid cells and a single copy of PSA cDNA on an ethidium bromide gel.
Among the 47 TRUS cases, 43 specimens were evaluable. Forty-two cases were negative before biopsy; among these patients, 4 cases (9.5%) converted to a positive RT-PCR PSA result. Both benign and malignant TRUS biopsies were capable of producing a positive RT-PCR PSA signal implicating iatrogenic dissemination of cells. All three TURP cases converted from a negative to a highly intense positive signal.
We conclude that a positive RT-PCR PSA signal may result from release of prostate cells into the peripheral circulation after a TRUS biopsy and TURP. TURP causes greater dissemination than TRUS. Based on these preliminary data, we recommend that future molecular staging studies should be based on blood specimens drawn before performance of TRUS biopsy. This may be an important mechanism of prostate cancer dissemination meriting further investigations.
通过针对前列腺特异性抗原（PSA）mRNA的逆转录聚合酶链反应（RT-PCR）来确定经直肠超声引导（TRUS）前列腺活检是否会导致前列腺细胞扩散至循环系统。
对50名男性在进行前列腺侵入性操作前后进行RT-PCR PSA分析。病例包括47例行TRUS检查的患者和3例行经尿道前列腺切除术（TURP）的患者。在操作前及操作后60分钟内采集外周静脉血（8毫升）。从分馏血液中提取总RNA，并通过β-肌动蛋白RT-PCR分析确保RNA/cDNA质量并进行标准化。PSA引物与外显子3和5杂交，产生一个254碱基对的PCR产物。该检测方法可在1亿个淋巴细胞背景中检测到1个LNCaP细胞，并在溴化乙锭凝胶上检测到单拷贝的PSA cDNA。
在47例TRUS病例中，43份标本可进行评估。42例在活检前为阴性；在这些患者中，4例（9.5%）转为RT-PCR PSA结果阳性。良性和恶性TRUS活检均能产生阳性RT-PCR PSA信号，提示细胞的医源性扩散。所有3例TURP病例均从阴性转为高强度阳性信号。
我们得出结论，TRUS活检和TURP后，RT-PCR PSA信号阳性可能是由于前列腺细胞释放到外周循环中所致。TURP导致的扩散比TRUS更严重。基于这些初步数据，我们建议未来的分子分期研究应基于TRUS活检前采集的血液标本。这可能是前列腺癌扩散的一个重要机制，值得进一步研究。
