前列腺特异性膜抗原和前列腺特异性抗原表达强度与前列腺癌Gleason评分之间的相关性研究

目的研究前列腺特异性膜抗原(PSMA)和前列腺特异性抗原(PSA)的表达强度与前列腺癌Gleason评分之间的相关性。方法制备抗PSMA膜外段表位的单克隆抗体,应用免疫组织化学方法检测前列腺癌中PSMA的表达,统计分析其与Gleason评分之间的相关性,并和PSA与Gleason评分之间的相关性进行对比。结果制备出8株分泌抗PSMA膜外段表位的单抗的杂交瘤细胞株。免疫组化结果表明,PSMA的表达强度与前列腺癌的Gleason评分之间存在相关性。在分化差的前列腺癌中,PSMA水平高于分化中等和分化良好的前列腺癌(P<0.01),而PSA在前列腺癌中的表达无明显差异(P>0.05)。结论PSMA表达水平在分化差的前列腺癌中明显升高,与Gleason评分存在相关性,可以作为前列腺癌的Gleason分级的标记物,提示PSMA可以作为对激素疗法效果不敏感的低分化前列腺癌抗体介导的免疫治疗靶点。

Correlation study of expression levels of prostate-specific membrane antigen and prostate-specific antigen with Gleason score of prostate carcinoma

Objective To study the correlation of prostate-specific membrane antigen(PSMA) and prostate-specific antigen (PSA) expression with Gleason score of prostate carcinoma. Methods Monoclonal antibodies against epitopes of PSMA extracellular domain were prepared, with which the expression of PSMA of prostate carcinoma (PC) was determined by immunohistochemical staining. Correlation of its expression with Gleason score of PC was statistically analyzed, and compared with that of PSA. Results Eight hybridoma cell lines secreting monoclonal antibodies specific for PSMA were prepared. PSMA expression level was positively correlated with Gleason score. In poorly differentiated prostate carcinoma, the expression intensity of PSMA was higher than that of medium-and well-differentiated prostate carcinoma (P<0.01). However, there was no correlation between level of PSA expression and Gleason score (P>0.05). Conclusion PSMA expression level may be used as a useful surrogate marker in Gleason grading of prostate carcinoma. It may be a more suitable target than PSA in antibody mediated immunotherapy against poorly differentiated prostate carcinoma which is usually not sensitive to hormonal therapy.