OBJECTIVETo investigate the inhibitory effects of (188)Re-labeled herceptin on the proliferation in vitro of breast carcinoma cell line (SKBR-3) overexpressing HER-2/neu proto-oncogene.

METHODSHerceptin was radiolabeled with (188)Re through a direct labeling method. SKBR-3 cells were cultured with (188)Re-Herceptin at different radioactivity doses (3.7x10(4), 18.5x10(4), 37x10(4), 55.5x10(4) and 74x10(4) Bq/ml) or with (188)Re-nmIgG and (188)ReO(4)(-) for comparison. The cell proliferation inhibition was determined with MTT colorimetric assay.

RESULTS(188)Re-Herceptin could markedly inhibit the growth of SKBR-3 cells in a radioactivity dose-dependent fashion, while the effect of (188)Re-nmIgG and (188)ReO(4)(-) showed rather poor inhibitory effect in vitro. The 50% inhibition doses (IC(50)) of (188)Re-Herceptin, (188)Re-nmIgG and (188)ReO(4)(-) were 76.1x10(4) Bq/L, 139.2x10(4) Bq/L and 175x10(4) Bq/L, respectively.

CONCLUSION(188)Re-Herceptin can effectively inhibit the growth of in vitro cultured breast cancer cells overexpressing HER-2/neu, and shows much potential for clinical use in beast cancer radioimmunotherapy.

Antibodies, Monoclonal ; chemistry ; pharmacology ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents ; pharmacology ; Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Immunotoxins ; pharmacology ; Radioisotopes ; chemistry ; pharmacology ; Receptor, ErbB-2 ; biosynthesis ; Rhenium ; chemistry ; pharmacology ; Trastuzumab

(188)Re(Rhenium) is easily obtained from an in-house (188)W/(188)Re generator that is similar to the current (99)Mo/(99m)Tc generator, making it very convenient for clinical use. This characteristic makes this radionuclide a promising candidate as a therapeutic agent. Polyethylenimine (PEI) is a cationic polymer and has been used as a gene delivery vector. Positively charged materials interact with cellular blood components, vascular endothelium, and plasma proteins. In this study, the authors investigated whether intratumoral injection of (188)Re labeled transferrin (Tf)-PEI conjugates exert the effect of radionuclide therapy against the tumor cells. When the diameters of the Ramos lymphoma (human Burkitt's lymphoma) xenografted tumors reached approximately 1 cm, 3 kinds of (188)Re bound compounds (HYNIC-PEI-Tf, HYNIC-PEI, (188)Re perrhenate) were injected directly into the tumors. There were increases in the retention of (188)Re inside the tumor when PEI was incorporated with (188)Re compared to the use of free 188Re. The (188)Re HYNIC-Tf-PEI showed the most retention inside the tumor (retention rate=approximately 97%). H&E stain of isolated tumor tissues showed that (188)Re labeled HYNIC-PEI-Tf caused extensive tumor necrosis. These results support (188)Re HYNIC-PEI-Tf as being a useful radiopharmaceutical agent to treat tumors when delievered by intratumoral injection.
Animals ; Burkitt Lymphoma/pathology/*radiotherapy ; Cations ; Female ; Injections, Intralesional ; Mice ; Mice, Inbred BALB C ; Pilot Projects ; Polyethyleneimine/chemistry/*pharmacology ; Radioisotopes/chemistry/*pharmacology ; Research Support, Non-U.S. Gov't ; Rhenium/chemistry/*pharmacology

BACKGROUNDPrevious studies showed that anti MHC-II monoclone antibody (MAb) only had partial inhibiting effect of alloreactive mixed lymphocyte reaction (MLR) in vitro and it was unsteady and non-persistent. The aim of this research was to determine whether radioactive isotope (188)Re marked MHC-II antibody could benefit the allograft acceptance in transplantation as compared to normal MHC-II antibody.

METHODS188Re was incorporated to 2E9/13F (ab')(2) which is against swine MHC class II antigen (MAb-(188)Re). Porcine peripheral blood mononuclear (PBMC) cells were examined for proliferation and cytokine mRNA expression after stimulation with MHC-II MAb or MAb-(188)Re.

RESULTSThe proliferative response of recipient PBMCs in mixed lymphocyte reaction (MLR) to donor alloantigen showed that the stimulation index of MAb-(188)Re group was significantly lower than the MHC-II MAb group and control (P < 0.05). mRNA expression of interleukin 2, interferon Υ and tumor necrosis factor α (type 1 cytokines) was lower in MAb-(188)Re group than the MHC-II MAb group, while interleukin 10 (type 2 cytokines) was higher in MAb-(188)Re group in the first 24 hours.

CONCLUSIONMAb-(188)Re could help the graft acceptance by inhibiting T cell proliferation, lowering the expression of type 1 cytokines and elevating the type 2 cytokines produced by PBMC.

Animals ; Antibodies, Monoclonal ; chemistry ; pharmacology ; Cell Proliferation ; drug effects ; Interleukin-10 ; genetics ; Interleukin-2 ; genetics ; Isoantigens ; immunology ; Leukocytes, Mononuclear ; drug effects ; radiation effects ; Lymphocyte Culture Test, Mixed ; Mitomycin ; pharmacology ; Radioisotopes ; Reverse Transcriptase Polymerase Chain Reaction ; Rhenium ; Swine ; Tumor Necrosis Factor-alpha ; genetics