Acta Medica Okayama volume19 issue1

We succeeded in the extraction of a substance from beef cornea and rabbit muscle, that markedly inhibits mitosis of sea urchin eggs. The substance extracted from beef cornea is non-dialysable and it can be separated into three fractions by DEAE-cellulose column. Although everyone of these fractions has an antimitotic action, that of fractions II and III is especially marked. These fractions are one of nucleoproteins that have adenine as base. The substance extracted from rabbit muscle is dialysable, and when it is fractionated through DEAE-cellulose column into three fractions, fraction I has no antimitotic effect but fractions II and III have it. Fraction II is one of nucleoproteins that have hypoxanthine as base. Carnin obtained from beef cornea or from rabbit muscle shows a typical protein wave, but after being treated with gas by passing oxygen through cornin solution the wave height is lowered. Carnin, however, is a very stable substance when kept dry in a desiccator.

According to the data obtained in this experiment by means of the geldiffusion technique, the specific antigen was not detected in MH134 ascitic tumor, comparing the anti-C3H liver sera with anti-MH 134 tumor sera, though a loss of organ specific antigen and weak antigenicity were found in MH134 tumor extract. In order to detect some qualitative alteration, supposedly a gain in antigenic components, the transplant rejection test was carried out. The result of this test indicates that the relative not absolute resistance could be induced to C3H mice by this prior sensitization with cell free active extract eluted from MH134 tumor tissue by Fluorocarbon treatment. During these experiments, it became clear that MH134 ascitic tumor cell has weak immunizing properties so that prolonged lapse of time and large dose of antigen are inevitably necessary. Moreover, through Fluorocarbon treatment of the tumor homogenate, the cellfree, serologically active antigen could be obtained, which will serve well for the induction of the isologous immunization.

From the data presented in this communication, it might be concluded that a cancer specific substance, which can be demonstrated in gel diffusion, is present in human cancer tissue, common to various epithelial cancers of different individuals, although it may vary in its concentration. Needless to say, this substance is quite different from the so-called interspecies antigen or organ specific antigen, as proved by the present experiments. Furthermore, this substance can be eluted well by the Fluorocarbon treatment and it displays physically and chemically unstable characteristics. This substance is likely to be included in the microsome fraction and soluble fraction which was determined by gel diffusion technique. However, the association of this substance with other specific antigenic substances of human cancer, concerned with "delayed type skin reaction", "cytopathogenic antiserum against cancer cell", and "complement fixing antibody in serum of patients with cancer", has not been elucidated in this study.

Both the cornea and muscle cornins have no effect at all on oxygen uptake of tissue, and likewise they catalase affect Qctivity not in any way. The corneacornin has an effect to reduce P/O ratio to about one half, but the muscle cornin does not show such an effect. Both comins decrease thc incorporation of P³² into nucleic acid fraction and DNA synthesis. In the ultracentrifugal analysis of nucleic acids during development of sea urchin eggs, cornins inhibit the polymerization of nucleic acids. In addition, both of these comins depress the incorporation of P³² into DNA and ribosome RNA of regenerating rat liver. Both comins inhibit the increase of -SH quantities before the cleavage of sea urchin eggs.