Sarrats Ariadna, Comet Josep, Tabarés Glòria, Ramírez Manel, Aleixandre R Núria, de Llorens Rafael, Peracaula Rosa
Unitat de Bioquímica i Biologia Molecular, Departament de Biologia, Universitat de Girona, Campus de Montilivi, Girona, Spain.
Prostate. 2010 Jan 1;70(1):1-9. doi: 10.1002/pros.21031.
Prostate-specific antigen (PSA) is the tumor marker currently used for prostate cancer (PCa) screening and diagnosis. However, its use is controversial as serum PSA levels are also increased in other non-malignant prostatic diseases such as benign prostatic hyperplasia (BPH). PSA sialic acid content is altered in tumor situation and modifies PSA's isoelectric point (pI). Our goal has been to evaluate serum PSA subforms from PCa and BPH patients by two-dimensional electrophoresis (2-DE) and to investigate whether they could be used to improve PCa diagnosis.
PSA from 20 PCa and 20 BPH patients' sera was subjected to a four-step method to obtain serum PSA 2-DE subforms from free PSA (fPSA) plus PSA released from the complex with alpha-1-antichymotrypsin. Relative percentages of PSA spots were quantified and subjected to statistical analysis.
Five PSA subforms (F1, F2, F3, F4, and F5) of different pI were obtained. Relative percentages of F3 (%F3) and F4 (%F4) were different between PCa and BPH groups. %F3 decreased in cancers and this decrease correlated with the cancer stage, while F4 behaved oppositely. These observations were also found when only focusing on the patients within the low total PSA (tPSA) range 2-20 ng/ml.
%F3 showed a tendency of higher sensitivity and specificity than the currently used tPSA and %fPSA tests. Therefore, %F3 measurement should be investigated in a larger cohort of patients to study whether it could be introduced to improve PCa diagnosis.
前列腺特异性抗原（PSA）是目前用于前列腺癌（PCa）筛查和诊断的肿瘤标志物。然而，其应用存在争议，因为血清PSA水平在其他非恶性前列腺疾病如良性前列腺增生（BPH）中也会升高。PSA的唾液酸含量在肿瘤情况下会发生改变，并改变PSA的等电点（pI）。我们的目标是通过二维电泳（2-DE）评估PCa和BPH患者的血清PSA亚型，并研究它们是否可用于改善PCa的诊断。
对20例PCa患者和20例BPH患者血清中的PSA采用四步法，从游离PSA（fPSA）以及与α-1-抗糜蛋白酶复合物中释放的PSA获得血清PSA 2-DE亚型。对PSA斑点的相对百分比进行定量并进行统计分析。
获得了5种不同pI的PSA亚型（F1、F2、F3、F4和F5）。PCa组和BPH组之间F3（%F3）和F4（%F4）的相对百分比不同。癌症患者中%F3降低，且这种降低与癌症分期相关，而F4则相反。仅关注总PSA（tPSA）范围在2-20 ng/ml的患者时，也发现了这些观察结果。
%F3显示出比目前使用的tPSA和%fPSA检测更高的敏感性和特异性趋势。因此，应在更大的患者队列中研究%F3测量，以探讨其是否可用于改善PCa诊断。
