Characterization of the protein protecting RNA from Acid precipitation and its evaluation as tumor-marker in gastrointestinal and gynecological cancer.

In a previous study, we observed increased protective activity against acid precipitation of poly (U) in the serum of tumor bearing mice and hepatoma patients. In the present study we purified and partially characterized the protein responsible for this phenomenon and measured the activity in the serum of patients with various cancers. Evidence is presented that this protein forms a complex with serum ribonucleases which results in the inactivation of enzymes and protection of RNA from acid precipitation.