[Secondary structure of RNA secreted by Ehrlich ascites carcinoma cells].

The RNA, secreted by the cells of Ehrlich ascite carcinoma stimulates the inoculability and growth of the tumour. It contains double-helical regions, is resistable to the effects of pancreatic RNAse, has a melting point at 74 degrees and is eluted from the hydroxylapatite column by 0,25 M phosphate buffer. During its interaction with ethidium bromide the RNA increases the fluorescence of the dye. The amount of double-helical regions in the RNA makes up to 60%. These double-helical regions are formed in the carcinoma-secreted RNA due to RNA self-supercoiling. This was demonstrated by fluorescence studies of the RNA-ethidium bromide complex under various RNA denaturation and renaturation conditions.