Distribution of Desoxyribose Nucleic Acid in Tumor Nuclei.

Abstract

The relative amts. of DNA per nucleus, detd. by absorption microspectrophotometry of Feulgen-stained sections, was measured in individual nuclei of 5 different tumor tissues. A methylcholanthrene-induced squamous cell carcinoma of the rat ventral prostate was compared with normal prostate epithelium and precancerous squamous cell metaplasia. Cloud-man S-91 mouse melanoma and a spontaneous benign skin papilloma were compared with normal skin. A transplanted mouse mammary carcinoma and a spontaneous mammary adenocarcinoma were compared with normal mouse mammary gland. DNA values were largely distributed into classes in a geometric progression. The tumors showed increases in DNA as compared with homologous control tissue with the exception of the benign papilloma. The occurrence of intermediate values and increased DNA classes is considered to be an expression of changes in chromosome content associated with mitosis and polyploidy rather than a disturbance in nucleic acid synthesis.