Cancer research
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Leydig cell tumors are usually benign tumors of the male gonad. However, if the tumor is malignant, no effective treatments are currently available. Leydig cell tumors express platelet-derived growth factor (PDGF), kit ligand and their respective receptors, PDGFR and c-kit. ⋯ Human Leydig cell tumors showed an intense expression of the phosphorylated form of c-kit and a less intense expression of phosphorylated PDGFRs. No activating mutations in common regions of mutation of the c-kit gene were found. Our studies suggest that Leydig cell tumors might be a potential target for imatinib therapy.
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Internal image anti-idiotypic antibodies are capable of mimicking tumor-associated antigens and thus may serve as surrogate for vaccination strategies in cancer patients. The monoclonal antibody (mAb) 6G6. C4 mimics an epitope specific for the human carcinoembryonic antigen (CEA) and generates a CEA-specific response (Ab3) in various experimental animals. ⋯ Finally, the Ab3 antisera detected single CEA-expressing tumor cells in suspension as shown by flow cytometry. Taken together, these data show in a model antigenically related to the human system that vaccination with scFv6G6. C4/GM-CSF improves vaccination against an endogenous tumor-associated antigen resulting in a highly specific humoral Ab3 response in vivo that is capable of bind single circulating CEA-positive tumor cells.