Kurose Kyouhei, Sakaguchi Masakiyo, Nasu Yasutomo, Ebara Shin, Kaku Haruki, Kariyama Reiko, Arao Yujirou, Miyazaki Masahiro, Tsushima Tomoyasu, Namba Masayoshi, Kumon Hiromi, Huh Nam-Ho
Department of Urology, Okayama University Graduate School of Medicine and Dentistry and Faculty of Health Sciences, Okayama, Japan.
J Urol. 2004 Mar;171(3):1314-8. doi: 10.1097/01.ju.0000101047.64379.d4.
We examined the expression of REIC/Dkk-3, a possible candidate for a tumor suppressor gene, in human renal clear cell carcinoma (RCCC) cell lines and sporadic RCCC surgical specimens.
Human RCCC cell lines (Caki-1, Caki-2, ACHN and KPK-1) and several control cell lines were used to examine the expression of REIC/Dkk-3 mRNA and characterize a newly raised antibody specific for REIC/Dkk-3 protein. Pairs of cancerous and adjacent noncancerous tissues were obtained from 20 patients with RCCC. Of them 17 and 7 cases were analyzed by real-time quantitative reverse transcriptase-polymerase chain reaction, and by Western blot analysis and/or immunohistochemical analysis, respectively.
The decreased expression of REIC/Dkk-3 mRNA and protein in human RCCC cell lines, and the specificity of the new antibody were confirmed. In a real-time quantitative reverse transcriptase-polymerase chain reaction study using 17 pairs of RCCC and adjacent normal tissues REIC/Dkk-3 mRNA levels were significantly decreased in carcinoma tissues (by 25% to approximately 95% in 15 pairs). Western blot analysis and immunohistochemistry revealed a significant decrease in REIC/Dkk-3 protein levels in 6 of the 7 and 13 of the 14 RCCC cases analyzed, respectively.
The decrease in REIC/Dkk-3 mRNA and protein levels was observed irrespective of tumor grade and stage, indicating the involvement of REIC/Dkk-3 in an initial step of malignant conversion. Consequently REIC/Dkk-3 could be a new molecular target for therapeutic measures against RCCC.
我们检测了REIC/Dkk-3（一种可能的肿瘤抑制基因候选物）在人肾透明细胞癌（RCCC）细胞系和散发性RCCC手术标本中的表达。
用人RCCC细胞系（Caki-1、Caki-2、ACHN和KPK-1）及几种对照细胞系检测REIC/Dkk-3 mRNA的表达，并鉴定一种新制备的针对REIC/Dkk-3蛋白的特异性抗体。从20例RCCC患者获取癌组织及相邻的非癌组织。其中17例和7例分别通过实时定量逆转录聚合酶链反应、蛋白质印迹分析和/或免疫组织化学分析进行检测。
证实了人RCCC细胞系中REIC/Dkk-3 mRNA和蛋白表达降低，以及新抗体的特异性。在一项使用17对RCCC及其相邻正常组织的实时定量逆转录聚合酶链反应研究中，癌组织中REIC/Dkk-3 mRNA水平显著降低（15对中降低25%至约95%）。蛋白质印迹分析和免疫组织化学显示，在分别分析的7例RCCC病例中的6例以及14例RCCC病例中的13例中，REIC/Dkk-3蛋白水平显著降低。
无论肿瘤分级和分期如何，均观察到REIC/Dkk-3 mRNA和蛋白水平降低，表明REIC/Dkk-3参与了恶性转化的初始步骤。因此，REIC/Dkk-3可能是针对RCCC治疗措施的新分子靶点。
