Identification of nuclear matrix protein alterations associated with renal cell carcinoma

Purpose: Neoplastic transformation, including renal cell carcinoma (RCC), is always accompanied by changes in nuclear morphology. Nuclear grading of RCC is based on characteristic alterations in nuclear shape, size, area and other morphologic parameters. The nuclear matrix, which forms the skeleton of the nucleus, determines nuclear morphology. Alterations in nuclear matrix protein (NMP) composition specific to tissue and cancer type have been described in a variety of human cancers. We conducted a study to analyze the nuclear matrix protein composition of renal cell carcinoma and compare it to that of normal renal tissue and renal cell carcinoma cells grown in culture. Materials and Methods: We analyzed the nuclear matrix protein composition of RCC tumor tissue and that of normal kidney tissue obtained from seventeen patients undergoing radical nephrectomy for RCC. We also analyzed the NMP composition of two renal cancer cell lines (A-498 and 769-P). Results: We were able to identify five different and unique NMPs which were present only in the human RCC tumor samples and were absent in all normal kidney tissue. One NMP was found specifically in the normal kidney tissue. All five RCC specific NMPs were also identified in the nuclear matrix of the two cell lines analyzed. Conclusions: Five nuclear matrix proteins specific and unique to RCC were identified. These NMPs are different from those previously identified in other tissues and neoplasms. The RCC specific NMPs identified in this study can potentially be used as diagnostic markers for renal cell carcinoma and for therapeutic tumor targeting.