The relationship between Ga-67 accumulation and cell cycle in malignant tumor cells in vitro.

Previously we reported that the deposition of 67Ga into malignant tumor may be a sensitive index of proliferative activity in tumor cells. For the purpose of elucidation of this hypothesis, we investigated the relationship between the accumulation of 67Ga into malignant tumor cells and the cell cycle in vitro. We discovered that the uptake of both 67Ga and 59Fe into synchronized mouse tumor cells reaches a peak at the G2 stage which precedes cellular proliferation. Both iron and transferrin are specifically required by cells in culture for cell division, and the fact that 67Ga and 59Fe uptake into tumor cells peaks at the G2 stage of the cell cycle suggests that there is a correlation between 67Ga uptake and the rate of cellular proliferation in malignant tumor cells.