[Electron microscopic and immunological studies concerning the effect on the antitumor activity of sizofiran (SPG) combined with radiotherapy for cervical cancer].

It has been well known that Sizofiran (SPG) cultured from the Schizophyllum commune Fries activates the macrophages and induces the cytotoxic lymphocytes in some cancers. In this study, we observed electronmicroscopically the macrophages around the cancer tissue from the patients with uterine cervical cancer after the treatment with SPG. At the same time, their immune responses were also examined by analyzing lymphocyte subsets, ADCC and NK activity in peripheral blood. A considerable number of erratic macrophage with well developed Golgi apparatus, endoplasmic reticulum and mitochondria were found in the uterine cervical cancer tissue from the patients treated with SPG under radiotherapy. Simultaneously, we identified the lysosome granules with a bright filament structure which appeared to be specific for SPG. In the immune responses evaluated by analyses of peripheral blood, the number of CD 16+ cells and NK activity significantly increased in the patients treated with SPG as compared with non-treated group. The present results indicate that SPG-immunotherapy combined with radiotherapy not only induces the cytotoxic activity of macrophage but also augments NK activity in the patients with uterine cervical cancer.