Immunocytochemical localization of the transferrin receptor (TfR) using a monoclonal antibody in HeLa cells was investigated by microscopy and electron microscopy. In addition, changes in transferrin receptor localization evoked by cisplatinum diammine dichloride (CDDP) were examined. The results were as follows:
1. In proliferating cells, TfR was found in the cell membrane and electron microscopic investigations revealed that TfR was localized in a scattered fashion in the cell membrane, microvillus-like projections and intercellular vesicles.
2. After CDDP treatment, microvillus-like projections and intercellular vesicles were not as prominent as in the control group and the quantity of TfR decreased.
3. In some relatively highly degenerated cells by CDDP, many TfRs were demonstrated, suggesting that the mechanism of TfR expression, which reflects the proliferative ability of cancer cells, should be investigated.
