Ribonuclease induction in cells transformed by Agrobacterium tumefaciens

Serum ribonucleases in pancreatic cancer: relation to tumor histology

Serum Ribonuclease (RNase, EC. 3. 1. 4. 22) of normal persons and of patients with chronic pancreatitis, or pancreatic cancer was determined with poly (C) as substrate. Strikingly abnormal elevations occured in the serum RNase of patients with pancreatic cancer (p less than 0.001). Average serum RNase values of 18 normal persons, 10 patients with chronic pancreatitis and 26 patients with pancreatic cancer were 92, 118, and 249 units, respectively. In patients with pancreatic cancer, we compared the RNase level with four histologic types (ductar cell adenocarcinoma, anaplastic cell carcinoma, acinar cell carcinoma, and islet cell carcinoma). Adenocarcinoma showed higher activity than the other histologic types (p less than 0.005). When we compared the serum of pancreatic cancer and pancreatic cancer tumor extract with normal serum and normal pancreas extract, strikingly different phosphocellulose chromatographic pattern were evident. The correlation of increased serum RNase levels with tumor histology and different chromatographic pattern may explain the new enzyme production in cancer patients, and have biological significance in the development of pancreatic cancer.

Elevated serum ribonuclease in patients with pancreatic cancer

Serum RNase (ribonuclease) of normal persons and of patients with pancreatitis, carcinoma of pancreas, or other neoplasms was determined with poly(C) as substrate. Strikingly abnormal elevations occur in the serum RNase of patients with pancreatic cancer. There is no elevation in the serum RNase level of patients with pancreatitis. Average serum RNase values of 52 normal persons, 10 patients with pancreatitis, 30 patients with pancreatic cancer, 28 patients with breast cancer, 11 patients with lung cancer, 20 patients with colon cancer, six patients with stomach cancer, and four patients with liver cancer, respectively, were 104, 120, 383, 131, 173, 197, 194, and 152 units/ml of serum. Ninety percent of the patients with pancreatic cancer were above the level of 250 units of serum and 90% of all patients with varied cancers were below this level. In the presence of severe renal insufficiency, marked elevation of serum RNase was also observed. Serum RNase, because of its unique specificity, pancreatic origin, and its abnormal elevation in sera of patients with pancreatic cancer, serves as a reliable biochemical marker of carcinoma of the pancreas in the presence of normal renal function.

Isoenzymes of acid phosphatase and non-specific esterases in cultures of neoplastic and normal tobacco tissues

Axenic cultures of normal, habituated and crown gall teratoma were grown under varying conditions to examine the effects of environment on the expression of neoplastic character. Acid phosphatase patterns on polyacrylamide gels did not vary greatly among tissues although there were differences in acid phosphatase activity between various strains of Agrobacterium tumefaciens, the bacteria which cause crown gall. Certain esterase isoenzymes were found only in tissues grown on specific media, while others were tissue-specific but independent of the nature of the medium. Comparisons of liquid and solid grown cultures revealed that culture conditions also influence esterase expression. Both sunflower and tobacco crown gall tissue contained an esterase not found in habituated or normal tissues, and similar in electrophoretic mobility to an esterase found in extracts of the bacteria that had induced the tumors. The basic difference between the three tissue types studied is the manner in which they respond to a given environment.

Chromatin-directed Ribonucleic Acid Synthesis: A Comparison of Chromatins Isolated from Healthy, Avirulent Agrobacterium tumefaciens Inoculated, and Crown-Gall Tumor Tissues of Vicia faba

Chromatin was extracted from healthy, avirulent Agrobacterium tumefaciens inoculated, and crown-gall tumor Vicia faba internodes of the same age. Chromatin from crown-gall tissue produced 5 times more RNA per 100 micrograms of DNA than chromatin from the healthy tissue. When template availability was compared using chromatin with saturating amounts of Escherichia coli RNA polymerase, chromatin from crown-gall tissue had 36% more available template than the controls. In addition, when gamma-(32)P-ATP was incorporated into the RNA synthesizing reaction mixture, with saturating amounts of E. coli RNA polymerase, there were twice as many RNA chain starts in tumor as in control tissue.

Changes in the Ribonuclease Activity of Flax Cotyledons following Inoculation with Flax Rust

There was a significant increase in the ribonuclease activity of both resistant (Bombay) and susceptible (Bison) varieties of flax (Linum usitatissimum L.) 3 to 4 days after inoculation with flax rust (Melampsora lini [Pers.] Lev., race No. 3). A second and much greater increase in the activity of this enzyme occurred only in the susceptible host at later stages of disease development. While a similar increase in ribonuclease level was also caused by mechanical injury, evidence is presented showing qualitative differences between the enzyme from parasitized tissue and that from the mechanically injured cotyledons. Comparison of the enzyme from healthy and inoculated cotyledons and from flax rust revealed the presence of a relatively unstable component and some unique catalytic properties in the enzyme from inoculated cotyledons.

Evidence for the Presence of Bacteria-specific Proteins in Sterile Crown Gall Tumor Tissue

Cross-reacting antigens were found in bacteria-free crown gall tumor tissue tested with serum prepared against Agrobacterium tumefaciens (Smith and Towns.) Conn., but no such antigens were detected in callus tissue. Soluble proteins from tumor tissue, callus tissue, and the crown gall bacteria were fractionated on a DEAE-Sephadex (A-50) column. The diethylaminoethyl-Sephadex elution profile for tumor tissue showed three protein fractions that were not detected in the callus tissue. Two of these protein fractions were shown to be exclusively bacteria specific. Besides these qualitative differences between the two tissues, significant quantitative differences in the amount of protein fractions were also observed. The diethylaminoethyl-Sephadex column fractions from tumorigenic strain of A. tumefaciens corresponding in position to the three additional peaks in the tumor tissue also showed cross-reacting antigens when tested with serum prepared against sterile tumor tissue. It is suggested that tumor formation by A. tumefaciens involves integration of the bacterial genome into the host-cell genome.

Plant Nucleases: III. Polyacrylamide Gel Electrophoresis of Corn Ribonuclease Isoenzymes

Isoenzymes of RNase were detected in plant extracts after polyacrylamide gel electrophoresis with a new buffer system. The gels were incubated in an RNA solution, then dipped for 30 seconds into 0.2% toluidine blue. The method is rapid and is sensitive to very small amounts of RNase. The effects of buffers and ethylenediaminetetraacetate on the different enzymes are illustrated by photographs and scans of the gels.RNase I, from endosperms and roots, was the fastest-moving corn RNase. Two isoenzymes of corn RNase II, from microsomes, were detected in the hybrid WF9 x M14, while each parental inbred had one of the isoenzymes. Three isoenzymes of corn Nuclease I, from crude mitochondria, had about the same mobility as the RNase II isoenzymes, but were inhibited by ethylenediaminetetraacetate. RNases were also detected in tobacco and wild carrot tissue cultures.

Polyacrylamide gel analysis of high molecular weight ribonucleic Acid from etiolated and green cucumber cotyledons

Cucumis sativus L. seeds and 5-day-old dark-grown cotyledons contain 25 and 18 S cytoplasmic ribosomal RNAs as main components. The major increase in nucleic acid content in both green and etiolated cotyledons occurs between days 5 and 7 of germination. This increase is characterized by an important synthesis of 23 and 16 S plastid (chloroplast and proplastid) ribosomal RNAs. Proplastid RNA synthesis appears to continue for a longer period in the dark-grown cotyledons, despite a total RNA content considerably less than in the light-grown cotyledons.The nonribosomal distribution of the chloroplast and proplastid ribosomal RNAs observed in all cases (after extraction and fractionation) results from the lability of the 23 S component. This degradation increases if the chloroplasts and proplastids are isolated prior to extraction of their nucleic acid.