Junker Kerstin, Hindermann Winfried, von Eggeling Ferdinand, Diegmann Julia, Haessler Kirstin, Schubert Joerg
Department of Urology, Institute of Human Genetics and Anthropology, Friedrich-Schiller-University, Jena, Germany.
J Urol. 2005 Jun;173(6):2150-3. doi: 10.1097/01.ju.0000158121.49085.ba.
To date there have been no specific tumor markers available for the differential diagnosis of renal cell carcinoma (RCC). In an earlier study we identified high RNA expression of CD70 in clear cell RCC. CD70 is a type II transmembrane protein belonging to the tumor necrosis factor family. It represents the ligand for CD27, a glycosylated transmembrane protein of the tumor necrosis factor receptor family. To our knowledge the function of CD70 in solid tumors is not known. In the current study we analyzed CD70 protein expression in different RCC subtypes.
A total of 68 tumor samples of different histopathological subtypes were investigated by immunochemistry, including 41 clear cell, 19 papillary and 5 chromophobe RCCs, and 3 oncocytomas as well as their normal tissue counterparts. Immunochemistry was performed on frozen tissue samples using monoclonal antibody against CD70.
None of the normal kidney tissues showed CD70 expression. In contrast, all clear cell RCCs expressed CD70 at a high level. Positive immunostaining was observed in 1 papillary (5%) and in 1 chromophobe (20%) RCC. Five papillary tumor samples (26%) showed focal staining in less than 5% of cells. All other samples were negative for CD70.
Our study identified CD70 as a new specific tumor marker for clear cell RCC. This new marker can be used for differential diagnosis in cases of uncertain histological classification. The function of this protein in tumorigenesis and its use as a diagnostic marker in serum and urine or as a therapeutic tool must be investigated in further studies.
迄今为止，尚无用于肾细胞癌（RCC）鉴别诊断的特异性肿瘤标志物。在一项早期研究中，我们发现透明细胞RCC中CD70的RNA表达较高。CD70是一种属于肿瘤坏死因子家族的II型跨膜蛋白。它是CD27的配体，CD27是肿瘤坏死因子受体家族的一种糖基化跨膜蛋白。据我们所知，CD70在实体瘤中的功能尚不清楚。在本研究中，我们分析了不同RCC亚型中CD70蛋白的表达情况。
通过免疫化学对68个不同组织病理学亚型的肿瘤样本进行研究，包括41个透明细胞、19个乳头状和5个嫌色性RCC，以及另外3个嗜酸细胞瘤及其相应的正常组织。使用抗CD70单克隆抗体对冷冻组织样本进行免疫化学检测。
所有正常肾组织均未显示CD70表达。相比之下，所有透明细胞RCC均高水平表达CD70。在1个乳头状RCC（5%）和1个嫌色性RCC（20%）中观察到阳性免疫染色。5个乳头状肿瘤样本（26%）显示不到5%的细胞呈局灶性染色。所有其他样本的CD70均为阴性。
我们的研究将CD70鉴定为透明细胞RCC的一种新的特异性肿瘤标志物。这种新标志物可用于组织学分类不确定病例的鉴别诊断。该蛋白在肿瘤发生中的功能及其作为血清和尿液诊断标志物或治疗工具的用途必须在进一步研究中进行探讨。
