Characteristics of two wheat germ agglutinin-resistant variants of B16 mouse melanoma cells with reduced tumorigenicity.

Abstract

Two variants of B16 mouse melanoma cells, selected for their resistance to toxic levels of wheat germ agglutinin isolectin 1 (WGA-1) in serum-free medium, showed by chromosome analysis that they are still mouse cell-lines, continue to produce melanin, and are less tumorigenic in mice than the parent B16 cells. The variants showed a marked decrease in cell agglutination with the wheat germ lectin and a slight increase in cell agglutination with concanavalin A. The binding of 125I-labeled wheat germ agglutinin to the two variant lines was likewise decreased over a 10(3)-fold range of lectin concentrations. Terminal sialyl residues were critical in WGA-1 binding to the wild-type cells. The binding data indicated a decrease in high-affinity binding as well as a decrease in the total number of binding sites in the variants. Polyacrylamide gel electrophoresis, followed by affinity staining with 125I-wheat germ agglutinin, showed alterations in the wheat germ agglutinin-binding glycoproteins in the variants compared to those of the parent cell line. However, lactoperoxidase-catalyzed iodination revealed a similar cell-surface protein pattern among the three cell lines. Radioactive glycoproteins secreted or shed by the three cell lines grown in the presence of [3H]glucosamine in serum-free medium were fractionated on the basis of their interaction with WGA-Sepharose (2 mg/mL). The WGA-bound glycoproteins from the two variants had molecular weights of 92,000, 56,000, and 42,000. None of these components was detected in the parent cell-line. A major WGA-binding glycoprotein, which accounted for 37% of the total [3H]glucosamine incorporated, was isolated from the spent medium of the parent mouse melanoma cell-line. This glycoprotein was apparently absent in the WGA-1-resistant variants.

• Authors: P D Pinnaduwage, V P Bhavanandan, E A Davidson
• Journal: Carbohydrate research (Carbohydr Res) Vol. 151 Pg. 37-50 (Aug 15 1986) ISSN: 0008-6215 [Print] Netherlands
• PMID: 3768899 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Iodine Radioisotopes
• Receptors, Mitogen
• Wheat Germ Agglutinins
• wheat germ agglutinin receptor

Topics

• Agglutination Tests
• Animals
• Cell Line
• Cell Membrane (metabolism)
• Drug Resistance
• Iodine Radioisotopes
• Melanoma, Experimental (drug therapy, pathology)
• Mice
• Receptors, Mitogen (metabolism)
• Wheat Germ Agglutinins (therapeutic use, toxicity)