Cytochemical studies of nuclear DNA and RNA in normal and abnormal keratinizing tissues

The distribution patterns of nuclear DNA and RNA in normal and abnormal keratinizing tissues of human skin were examined by electron microscopy, using an enzyme digestion technique. We found that the distribution of nucleic acids in the nuclei of epidermal cells during keratinization changes gradually. In the hair cells, particularly in the cells of hair cortex and Henle's layer of inner root sheath, essentially similar findings were observed. On the other hand, the distribution patterns observed in the tumor cells of calcifying epithelioma and the parakeratotic cells of psoriasis were different from each other and different from the distribution patterns of normal keratinizing tissue, hair, and epidermis. It seems that a similar pattern of reorganization of nucleic acids occurs in the nucleic of normal keratinizing cells as the cells keratinize. However, in abnormal tissue, it seems that the reorganization pattern of nucleic acids in the nuclei is different in each case.