Identification of Nuclear Structural Protein Alterations Associated with Classic Seminomas: A Pilot Proteomic Study
E Leman, A Magheli, KM Yong, S Hinz, R Getzenberg, GJ Netto. Johns Hopkins University, Baltimore
Background: Currently, there are no specific markers available for early detection or monitoring testicular germ cell tumors. Based upon an approach that targets nuclear structure, we have identified a set of proteins that are specific for seminomatous germ cell tumors which may have future clinical utility for detection and or monitoring of seminoma.
Design: Fresh frozen tissues were obtained from testicular samples of five organ donor with no evidence of germ cell tumors as well as six surgical pathology specimens of pure classic seminomas obtained from the pathology departments of the two participating hospitals. Nuclear matrix proteins were extracted and separated using a high resolution two-dimensional electrophoresis gel system. The proteins were then identified by mass spectrometry analysis. Purified rabbit polyclonal antibody against CDK10 (Abgent, San Diego, CA) and chicken polyclonal antibody against StARD7 (ProSci Inc., Poway, CA) were subsequently used for immunoblot analyses in order to validate two protein spots identified by mass spectrometry analysis.
Results: Our analysis revealed seven nuclear matrix proteins associated with normal testes, which did not appear in any of the examined seminomas. In the seminomas, four nuclear matrix proteins were identified that were absent in the control normal testicular tissue. Mass spectrometric and immunoblot analyses of these proteins revealed that one of the proteins identified in the normal testes was StARD 7 (StAR-related lipid transfer protein 7). In the seminoma tissues, one of the identified proteins was CDK10 (Cell division protein kinase 10). Both StARD7 and CDK10 are potentially involved in cell differentiation and growth.
Conclusions: This is the first study to examine the role of nuclear structural proteins as potential biomarkers in testicular cancer. We are currently further examining the roles of some of the identified proteins as biomarkers for the disease. If confirmed in a larger cohort, CDK10 could be pursued as a diagnostic and potential target of therapy in seminomas.
Category: Genitourinary (including renal tumors)
Monday, March 22, 2010 1:00 PM
Poster Session II # 100, Monday Afternoon