A chick embryo model for metastatic human prostate cancer.

OBJECTIVE

To establish a suitable experimental model of bone and liver micrometastases from human prostate cancer for evaluating antitumor agents.

METHODS

PC-3 cells, an androgen-independent prostate cancer cell line, were inoculated into the chorioallantoic membrane vein of 10-day-old chick embryos (10(6) cells/egg). The polymerase chain reaction product for the human beta-globin gene in chick embryo femur and liver was quantified at various time points after inoculation, when immunohistochemical staining was done for Ki-67 antigen and cytokeratin. The antitumor effect of suramin was evaluated using the model, as was regional blood flow after thallium injection.

RESULTS

Micrometastases were identified in bone and liver 1 day after inoculation and grew to form established metastatic foci in all embryos. Suramin showed significant antitumor effect for liver metastases, but not for those in bone where blood flow was relatively low.

CONCLUSION

The chick embryo system provides a highly reproducible model for bone and liver micrometastases from human prostate cancer, suitable for evaluating antineoplastic agents at an early stage of the metastatic process.