Yuasa Takeshi, Yoshiki Tatsuhiro, Isono Takahiro, Tanaka Tsutomu, Okada Yusaku
Department of Urology, Shiga University of Medical Science, Otsu, Japan.
Adv Exp Med Biol. 2003;539(Pt A):33-46. doi: 10.1007/978-1-4419-8889-8_3.
Uroplakins (UPs), urothelium-specific transmembrane proteins, are present only in urothelia and may be good candidates as tumor markers specific for transitional cell carcinomas (TCCs). We investigated the expression of UP genes in the tissues and peripheral blood of patients with TCCs.
We determined the nucleotide sequences of UPs by a polymerase chain reaction (PCR)-based method. We then investigated UP gene expression in tissues from 12 patients with TCC by reverse transcription (RT)-PCR. We also investigated UP gene expression in peripheral blood of 12 other patients with TCC by nested RT-PCR. Polyclonal and monoclonal antibodies against UPs were generated using synthesized polypeptides and recombinant protein, respectively, as immunogens.
We determined the nucleotide sequence of human UP-Ib, UP-II, and UP-III cDNAs and produced gene-specific primer pairs for each and for UP-Ia. UP genes were expressed in both cancerous and non-cancerous urothelia taken from all patients examined (as detected by RT-PCR). The detection sensitivity of our assay system was such that 1 cancer cell could be detected in 5 mL of peripheral blood. UP gene-expression was also detected in the peripheral blood of 3 patients with metastatic TCC, but not from 9 patients with non-metastatic TCC or from 3 healthy volunteers. Antibodies against both UP-Ia and UP-Ib reacted with the cell membrane of TCCs.
UPs may be employed as tumor markers for TCCs, because they are highly conserved and well expressed in non-cancerous and cancerous cells. Furthermore, detection of UP gene expression in blood by nested RT-PCR may provide helpful information in the diagnosis and management of TCCs. We are currently expanding an immunohistochemical study by targeting a larger number of patients to examine the clinical usefulness of these antibodies.
尿路上皮素（UPs）是尿路上皮特异性跨膜蛋白，仅存在于尿路上皮中，可能是作为移行细胞癌（TCCs）特异性肿瘤标志物的良好候选物。我们研究了TCC患者组织和外周血中UP基因的表达。
我们通过基于聚合酶链反应（PCR）的方法确定了UPs的核苷酸序列。然后，我们通过逆转录（RT）-PCR研究了12例TCC患者组织中UP基因的表达。我们还通过巢式RT-PCR研究了另外12例TCC患者外周血中UP基因的表达。分别使用合成多肽和重组蛋白作为免疫原，制备了针对UPs的多克隆和单克隆抗体。
我们确定了人UP-Ib、UP-II和UP-III cDNA的核苷酸序列，并为每个基因以及UP-Ia制备了基因特异性引物对。在所检查的所有患者的癌性和非癌性尿路上皮中均检测到UP基因表达（通过RT-PCR检测）。我们检测系统的检测灵敏度使得在5 mL外周血中可以检测到1个癌细胞。在3例转移性TCC患者的外周血中也检测到了UP基因表达，但在9例非转移性TCC患者或3名健康志愿者的外周血中未检测到。针对UP-Ia和UP-Ib的抗体均与TCCs的细胞膜发生反应。
UPs可能用作TCCs的肿瘤标志物，因为它们在非癌性和癌性细胞中高度保守且表达良好。此外，通过巢式RT-PCR检测血液中UP基因表达可能为TCCs的诊断和管理提供有用信息。我们目前正在通过针对更多患者开展免疫组化研究，以检验这些抗体的临床实用性。
