[188Re-labeled herceptin inhibits proliferation of breast cancer cell line SKBR-3 in vitro].

Objective: To 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.

Methods: Herceptin 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.