Prostasome‐derived proteins capable of eliciting an immune response in prostate cancer patients

KG Ronquist, L Carlsson, G Ronquist… - … journal of cancer, 2006 - Wiley Online Library
KG Ronquist, L Carlsson, G Ronquist, S Nilsson, A Larsson
International journal of cancer, 2006Wiley Online Library
Prostate cancer consistently remains a difficult clinical enigma. Therefore, the development
of novel strategies for diagnosis and treatment (eg immunotherapy) of prostate cancer is
essential. We tried to identify the prostasome‐derived proteins that were immunogenic in
prostate cancer patients. Prostate cancer patients' sera (n= 44) with high enzyme‐linked
immunosorbent assay (ELISA) titers against prostasomes were selected for immunoblotting
against purified seminal prostasomes. The SDS‐PAGE and immunoblotting experiments …
Abstract
Prostate cancer consistently remains a difficult clinical enigma. Therefore, the development of novel strategies for diagnosis and treatment (e.g. immunotherapy) of prostate cancer is essential. We tried to identify the prostasome‐derived proteins that were immunogenic in prostate cancer patients. Prostate cancer patients' sera (n = 44) with high enzyme‐linked immunosorbent assay (ELISA) titers against prostasomes were selected for immunoblotting against purified seminal prostasomes. The SDS‐PAGE and immunoblotting experiments were performed with Bio‐Rad systems. Twenty‐five of the recognized proteins were isolated and analyzed by means of mass spectrometry. Out of 44 patients' sera, 31 (70%) demonstrated in immunoblotting experiments reactivity against several prostasomal protein bands in the molecular weight range of 10–200 kDa. Some of the bands (55, 70 and 170 kDa) were more frequently recognized by the patients' sera. Concomitantly run control sera generated only very weak or no bands at all. The most frequently occurring prostasomal proteins were identified as heat shock proteins (HSP 70, 71) and clusterin. This study identified the most important molecular targets of autoantibodies against prostasomes generated in connection with the development of prostate cancer in man. These immunogenic prostasomal proteins could be appropriate target molecules for specific immunotherapy of prostate cancer patients. © 2006 Wiley‐Liss, Inc.
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