Identification of nuclear structural protein alterations associated with seminomas.

Currently, there are no specific markers available for the early detection and for monitoring testicular cancer. Based upon an approach that targets nuclear structure, we have identified a set of proteins that are specific for seminomas, which may then have clinical utility for the disease. Utilizing samples obtained from men with no evidence of testicular cancer (n = 5) as well as those with seminomas (n = 6), nuclear matrix proteins were extracted and separated using a high-resolution two-dimensional electrophoresis gel system. The proteins were identified by mass spectrometry analysis. These analyses revealed seven nuclear matrix proteins associated with the normal testes, which did not appear in the seminomas. In the seminomas, four nuclear matrix proteins were identified to be associated with the disease that were absent in the normal testes. Mass spectrometric and immunoblot analyses of these proteins revealed that one of the proteins identified in the normal testes appears to be StAR-related lipid transfer protein 7 (StARD7). In the non-seminoma tissues, one of the identified proteins appears to be cell division protein kinase 10 (CDK10). Both StarD7 and CDK10 could potentially be involved in cell differentiation and growth, and thus may serve as potential targets for therapy of prognostication of seminomas. This is the first study to examine the role of nuclear structural proteins as potential biomarkers in testicular cancer. We are currently examining the roles of some of the identified proteins as potential biomarkers for the disease.