Localization of gallium in tumor cells. Electron microscopy, electron probe microanalysis and analytical ion...

The incorporation of gallium in tumor cells in vitro and in solid tumors was studied with electron microscopy and two microanalytical techniques. It was thus possible (1) to directly prove that gallium is concentrated in lysosomes of tumor cells; (2) to demonstrate that in these lysosomes, gallium is precipitated with phosphorus; and (3) to propose a mechanism of gallium concentration in tumor cells; in this mechanism, the accumulation of gallium as phosphate salts in lysosomes is directly related to the acid phosphatase activity of these organelles.