Nucleic Acids

XII. Comparison of DNA from Gastric Cancer with That from Gastric Mucosa

Abstract

1. DNAs were prepared from human gastric cancer and gastric mucosa according to Sakamoto.
2. Their physical, chemical and biological properties were carefully examined.
3. Adenine amounted less a little and guanine less in a larger grade and cytosine distinctly more in the cancer DNA than in the mucosa DNA.
4. The cancer DNA absorbs ultraviolet light more strongly than the noncancerous.
5. The cancer DNA is less dextrorotatory than the noncancerous.
6. The cancer DNA is potent to give stronger skin reaction in cancer patients than in the noncancerous.
7. The cancer DNA shows more intensive Schiff reaction than the noncancerous within 6 hours after the commencement, when incubated with 0.01 N HCl (pH of the solutions 2.0-2.1) at 37°C. The maximum Schiff reaction occurring after the 6 th hour is also stronger in the cancerous DNA than in the noncancerous. Namely, the purines are assumed to be bound less stably against acid in the cancerous DNA than in the non-cancerous.
In the respects from 5. to 7., the cancer DNA is to the mucosa DNA what the placenta DNA is to the spleen DNA.