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Updated: Aug 18, 2026
The Use of Reverse Phase Protein Arrays (RPPA) to Explore Protein Expression Variation within Individual Renal Cell Cancers
Published on: January 22, 2013
CD70: a new tumor specific biomarker for renal cell carcinoma
Kerstin Junker1, Winfried Hindermann, Ferdinand von Eggeling
1Department of Urology, Institute of Human Genetics and Anthropology, Friedrich-Schiller-University, Jena, Germany. kerstin.junker@med.uni-jena.de
Purpose:
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.
Materials And Methods:
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.
Results:
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.
Conclusions:
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.
Insights
CD70 is identified as a specific tumor marker for clear cell renal cell carcinoma (RCC). This finding aids in the differential diagnosis of RCC subtypes, offering a new diagnostic tool for uncertain cases.
Area of Science:
- Oncology
- Immunology
- Molecular Biology
Background:
- Renal cell carcinoma (RCC) lacks specific diagnostic tumor markers.
- Previous research indicated high RNA expression of CD70 in clear cell RCC.
- CD70, a TNF family protein, has an unknown function in solid tumors.
Purpose of the Study:
- To investigate CD70 protein expression across different RCC subtypes.
- To evaluate CD70 as a potential diagnostic marker for RCC.
- To determine the specificity of CD70 in differentiating RCC types.
Main Methods:
- Immunohistochemistry was performed on 68 RCC tumor samples (41 clear cell, 19 papillary, 5 chromophobe) and normal kidney tissues.
- Monoclonal antibody against CD70 was used on frozen tissue samples.
- Analysis included clear cell, papillary, and chromophobe RCC subtypes, as well as oncocytomas.
Main Results:
- No CD70 expression was detected in normal kidney tissues.
- All clear cell RCC samples exhibited high CD70 protein expression.
- Limited CD70 expression was observed in one papillary and one chromophobe RCC case; others were negative.
Conclusions:
- CD70 is a novel and specific tumor marker for clear cell RCC.
- This marker can assist in the differential diagnosis of ambiguous RCC histological classifications.
- Further research is needed to explore CD70's role in tumorigenesis and its potential as a diagnostic or therapeutic agent.
