Subong E N, Shue M J, Epstein J I, Briggman J V, Chan P K, Partin A W
Department of Urology, Johns Hopkins Hospital, Baltimore, Maryland 21287-2101, USA.
Prostate. 1999 Jun 1;39(4):298-304. doi: 10.1002/(sici)1097-0045(19990601)39:4<298::aid-pros11>3.0.co;2-m.
The nuclear protein B23, nucleophosmin, is an RNA-associated nucleolar phosphoprotein reported to be more abundant in malignant and growing cells than in normal nondividing cells. We examined the levels of B23 in fresh human prostate tissue and in five human prostate cancer cell lines with monoclonal antibodies (mAb) to nucleophosmin (alpha-B23) and to human prostate cancer nuclear matrix proteins (PRO:4-216).
mAb PRO:4-216 and mAb alpha-B23 were used for protein level detection. Nuclear matrix proteins (NMPs) were prepared from prostate tumor and five human prostate cancer cell lines: LNCaP, TSU, DU145, PC-3, and PPC-1. The NMPs were run on one-dimensional and two-dimensional (2D) electrophoresis gels for Western blot analysis with the two mAbs. Histologic sections from paraffin-embedded normal and cancerous prostate tissue were stained immunohistochemically with both mAbs.
PRO:4-216 and B23 mAbs identified a 40-kD protein (pI approximately 5.0) by Western blot analysis in the human prostate cancer cell lines and on two-dimensional blots of human prostate cancer NMPs. Immunohistochemical staining demonstrated large punctate nuclear dots in most cancer nuclei, while staining of normal tissue was less intense or absent. Predominant reactivity was of epithelial nuclei, with some minor reactivity of stromal nuclei. Red blood cells (RBCs) and white blood cells (WBCs) were routinely negative.
PRO:4-216, previously characterized as recognizing prostate cancer nuclear matrix proteins, recognized B23/nucleophosmin. PRO:4-216 and alpha-B23 showed intense immunohistochemical staining of B23/nucleophosmin in cancer nuclei compared to adjacent normal cells in paraffin-embedded prostate tissue. This preliminary study showed the potential of B23 as a tumor marker for human prostate cancer.
核蛋白B23，即核磷蛋白，是一种与RNA相关的核仁磷蛋白，据报道在恶性增殖细胞中比在正常非分裂细胞中更为丰富。我们用针对核磷蛋白（α-B23）和人前列腺癌核基质蛋白（PRO:4-216）的单克隆抗体，检测了新鲜人前列腺组织及五个人前列腺癌细胞系中B23的水平。
使用单克隆抗体PRO:4-216和α-B23进行蛋白质水平检测。从前列腺肿瘤及五个人前列腺癌细胞系（LNCaP、TSU、DU145、PC-3和PPC-1）中制备核基质蛋白（NMPs）。将NMPs在一维和二维（2D）电泳凝胶上进行电泳，用这两种单克隆抗体进行蛋白质印迹分析。用这两种单克隆抗体对石蜡包埋的正常和癌性前列腺组织的组织学切片进行免疫组织化学染色。
通过蛋白质印迹分析，PRO:4-216和B23单克隆抗体在人前列腺癌细胞系及人前列腺癌NMPs的二维印迹上鉴定出一种40-kD的蛋白质（pI约为5.0）。免疫组织化学染色显示，大多数癌细胞核中有大的点状核染色，而正常组织的染色较弱或无染色。主要反应性见于上皮细胞核，间质细胞核有一些轻微反应性。红细胞（RBCs）和白细胞（WBCs）通常为阴性。
PRO:4-216以前被鉴定为识别前列腺癌核基质蛋白，实际上识别的是B23/核磷蛋白。与石蜡包埋的前列腺组织中相邻的正常细胞相比，PRO:4-216和α-B23在癌细胞核中对B23/核磷蛋白显示出强烈的免疫组织化学染色。这项初步研究显示了B23作为人前列腺癌肿瘤标志物的潜力。
