实时定量PCR技术检测前列腺癌微小转移的研究

Detection of Prostatic Carcinoma Micrometastasis by Real-time RT-PCR

通过利用TaqMan定量PCR检测前列腺增生和前列腺癌患者外周血中前列腺特异抗原(PSA)和前列腺特异膜抗原(PSMA)的表达量,建立了一种通过检测患者外周血单个核细胞中前列腺特异基因表达水平检测前列腺癌微小转移的方法.实验结果表明,PSA在转移癌、局限癌和增生患者组中与GAPDH的相对表达量分别为(2.63×10-3±3.4×10-4),(2.6×10-4±3.9×10-5)和(2.6×10-5±4.5×10-6),各组间有显著性差异(p<0.001);PSMA在各组间的相对表达量分别为(6.4×10-3±9.3×10-3),(5.0×10-4±8.3×10-5),(2.4×10-5±7.2×10-6),各组间亦存在着显著性差异(p<0.001).因此用定量PCR技术检测外周血中PSA和PSMA的表达水平,可区分前列腺转移癌、局限癌和增生患者,该方法可用于前列腺癌的早期诊断.

To study the markers and methods with high sensitivity and specificity m the detection of disseminated tumor cells in the peripheral blood, RNA was isolated from blood samples of patients with locally confined PCa, metastatic PCa and benign prostatic hyperplasia （BPH）. A real-time RT-PCR assay based on the TaqMan method was used to quantify PSA, PSMA and GAPDH （control） mRNA in the peripheral blood monocytes. For quantitation the copy numbers of PSA and PSMA transcripts were correlated to the copy number of GAPDH transcripts. The results show that there were significant differences in the PSA mRNA levels among BPH （PSA/GAPDH= 2.6 ×10^-5± 4.5 × 10^-6）, locally confined PCa （2.6 × 10^-4±3.9 × 10^-5） and metastatic PCa （2.63× 10^-3±3.4× 10^-4） derived specimens. And the differences of PSMA mRNA level among the three groups were also significant： PSMA/GAPDH ratio is （2.4×10^-5±7.2×10^-6） in BPH, （5.0×10^-4±8.3×10^-5） in locally confined PCa and （6.4× 10^-3± 9.3 × 10^-3） in metastatic PCa. Analyses using this real-time RT-PCR for PSA and PSMA mRNA measurement improve accuracy and liability of assessment of disseminated prostate epithelial cells in peripheral blood. Application of this technique in a clinical population may provide a better method for diagnosis and monitoring of prostate cancer patients.