Glycopeptides from the Surface of Control and Virus-Transformed Cells

Abstract

Glycopeptides were removed by trypsin digestion from the surface of control cells and cells transformed by Rous sarcoma virus, murine sarcoma virus, or polyoma virus. After digestion with pronase, the glycopeptides were analyzed by gel filtration. The elution profiles suggest that there are differences in the glycopeptides from the surface of control cells and those from transformed cells.

Transcriptional Regulation of the Human β-1,4-Galactosyltransferase V Gene in Cancer Cells

“…This exon-intron structure is highly conserved in the mouse. 3 A similar genomic organization has been observed for the human ␤-1,4-GalT VI gene (31), which was also suggested by the similarity between human ␤-1,4-GalTs V and VI at the amino acid levels (32) and by a closer position of human ␤-1,4-GalT VI to that of human ␤-1,4-GalT V rather to other ␤-1,4-GalTs in the phylogenetic tree (33).…”

“…The luciferase assay showed that the ␤-1,4-GalT V gene promoter is activated mostly in SH-SY5Y cells among the 2 T. Sato and K. Furukawa, unpublished data. 3 S. Hayakawa, T. Sato, and K. Furukawa, unpublished data. cell lines examined (Fig.…”

“…1). This was discovered by comparing the gel filtration patterns of glycopeptides obtained by Pronase digestion of metabolically labeled normal and malignant cell glycoproteins (2)(3)(4). Detailed structural studies of N-glycans isolated from baby hamster kidney cells and polyoma-or Rous sarcoma virustransformed baby hamster kidney cells showed that the increase in the GlcNAc␤136 branch attached to the Man␣136Man arm of the trimannosyl cores is the structural basis for this phenomenon (5,6).…”

The her-2/neu oncogene stimulates the transcription of N-acetylglucosaminyltransferase V and expression of its cell surface oligosaccharide products

“…A common alteration involves the increase in particular N-linked oligosaccharides when cells are transformed by a number of tumor viruses, including Rous sarcoma virus and polyoma virus, and oncogenes such as ras and fps/yes (Buck et al, 1971;Le Marer et al, 1992;Lu and Chaney, 1993;Pierce and Arango, 1986;Yamashita et al, 1984). These oligosaccharides contain a b(1,6) branched N-acetylglucosamine (GlcNAc) and their synthesis is catalyzed by the glycosyltransferase, N -acetylglucosaminyltransferase V (E. C. 2.…”

Not so sweet malignant transformation

“…Buck et al (1) reported this in 1970 for N-glycans from virus transformed cells. A number of immunologic epitopes identified as characteristic of malignant cells proved to be carbohydrate structures on lipids and proteins (2).…”