Ribonuclease Activity and Ribonucleic Acid Content of Homologous Human Normal and Cancer Cells

A RELATIONSHIP between the level of ribonuclease activity and ribonucleic acid content has recently been found to exist in the human placenta1and in hyperplastic bone marrow of the mouse2; such a relationship has also been shown to exist in different normal organs of the mouse3, as well as different epitheliomas in mice or rats4. On the other hand, results obtained with solid4and ascites tumours5suggest that cancerous epithelium might have less ribonuclease activity than a normal one. We have undertaken a study of the properties of the human uterine cervix, from which homologous normal and cancerous tissues can easily be obtained.