Uptake of radiolabelled herceptin by experimental mammary adenocarcinoma.

BACKGROUND

The aim of this study was to examine the biodistribution of (131)I-herceptin in C3H/Bi mice with transplantable mammary adenocarcinoma with a high frequency of C-erbB2 receptor expression.

MATERIAL AND METHODS

Mice C3H/Bi with subcutaneously transplanted mammary adenocarcinoma were used as animal model to study the interaction between C-erbB2 receptor and hercepin, a humanized anti-C-erbB2 monoclonal antibody. The expression of the gene encoding C-erbB2 receptor in the tumours was studied by the RT-PCR technique.

RESULTS

Expression of this gene was found in 66% of the studied cases. Similarly, the presence of the C-erbB2 receptor in 77% of the tumours was detected by a Western blot analysis with the use of herceptin. Biodistribution experiments of iodine-labelled herceptin in mice C3H/Bi with adenocarcinoma revealed its maximal accumulation in the tumours at 48 hours since the i.v. injection (7% ID/g). The tumour/muscle radioactivity ratio reached its highest value (above 20) also at 48 hours after the injection.

CONCLUSIONS

C3H/Bi mice with this adenocarcinoma may be a good experimental model to study herceptin, or its fragments, labelled with different radionuclids for preliminary evaluation of their usefulness in the therapeutic and diagnostic aspects of breast cancer.