The possible role of hematin and Mossbauer effect in the inhibition of osteosarcoma cell proliferation

Hematin, like many hematoporphyrines and porphyrin derivatives, shows a hig her affinity and preferential localization for tumor cells. These proper ti es are particularly interesting in view of their possible applications in a rmor treatment. I;The aim of the present work was to test the capability of porphyrines and resonant low energy gamma rays to produce some kind of sel ective inhibition of tumor cell proliferation. We investigated the role of hematin to potentiate the killing capability of 14.4 keV resonant gamma ray s from a Co-57 Mossbauer source. Human osteosarcoma cell cultures "MG-63" w ere incubated in the presence or absence of hematin (10(-4) to 10(-5) M) fo r 24 hours. They were successively irradiated for $ hours with 14.4 keV gam ma rays from a 3.7 GBq Co-57 source. The combined effects of hematin and re sonant gamma radiation were then examined and tested statistically for sign ificance. Different degrees of growth inhibition were observed when hematin alone, radiation alone, and hematin plus gamma rays were administered to t he cultures. Hematin, at the concentrations of 10(-4) M is capable of inhib iting tumor cells growth. While no significant effect is attributable to ir radiation alone, hematin plus irradiation show a larger inhibition than tha t expected for purely additive effects.