Heat shock proteins in renal cell carcinomas

Renal cell carcinoma (RCC) represents one of the most common cancer types in the Western World. One third of the RCC patients had metastasis at presentation with a poor 5-year survival. Nephrectomy is the most important treatment modality of this disease, since most of the RCCs are resistant to cytotoxic chemotherapy and radiation therapy. Recent immunotherapeutic approaches have been shown to improve the survival rate of RCC patients. Thus, RCC appears to have an immunogenic basis, and therefore represents an attractive target for immunotherapies. So far, only a few RCC-associated antigens have been characterized. However, with the implementation of ome-based technologies, an increasing number of tumor-associated antigens and tumor markers has been identified that includes various heat shock proteins (HSPs). RCC lesions demonstrate heterogeneous expression patterns for HSPs. In most cases overexpression of certain HSPs, such as HSP27, HSP70 and HSP72, has been detected both in RCC cell lines as well as in the tumor lesions when compared to normal kidney epithelium. Furthermore, HSPs play an important role in apoptotic cell death, in the regulation of cell proliferation and in the augmentation of lysis of RCC by HLA class I-restricted cytotoxic T lymphocytes. In this context, it is noteworthy that wild-type and mutated HSPs have been identified to act as tumor-associated antigens, which consequently resulted in the first clinical phase I and II trials using HSP for vaccination of RCC patients. In this chapter we will briefly present the relevance of HSPs in the pathomechanisms of RCC.