title: Mucin gel formed by tumorigenic squamous lung carcinoma cells has Le(a)-X oligosaccharides and excludes antibodies from underlying cells.
abstract: Cells of cloned lines of human squamous lung carcinomas elaborate large glycoproteins that are associated with their tumorigenic potential. Two groups of clones (called Le(a)-X-positive and Le(a)-X-negative) were studied that either do or do not express the Le(a)-X oligosaccharide associated with large glycoproteins and mucins secreted by these clones. Le(a)-X-positive cells elaborate a mucin gel complex associated with their apical surfaces, which appears as a mosaic of extracellular plates. Clones of this type are tumorigenic in nude rodents when injected s.c. or when introduced into the lungs via intrabronchial aerosol. By contrast, the Le(a)-X-negative clones do not form extracellular plates and are not tumorigenic in the lungs or subcutaneously. We demonstrate that the extracellular plates of Le(a)-X-positive cells exclude antibodies from interacting with the underlying squamous lung carcinoma cells and may therefore exert an immunoprotective effect. In support of this possibility it was found that: (a) There is a substantial inflammatory cell infiltrate associated with regressing nodules of Le(a)-X-negative cells in nude rodent lung and subcutaneous nodules, while there is no observable infiltration associated with progressing Le(a)-X-positive tumors. (b) In the brain (an immunoprivileged site) tumors develop and progress when either Le(a)-X-negative or -positive cells are introduced.
authors.affiliation: University of Colorado Cancer Center, Department of Biochemistry, Denver.
authors.forename: P L
authors.initials: PL
authors.lastname: Stranahan
authors.forename: R B
authors.initials: RB
authors.lastname: Howard
authors.forename: O
authors.initials: O
authors.lastname: Pfenninger
authors.forename: M E
authors.initials: ME
authors.lastname: Cowen
authors.forename: M R
authors.initials: MR
authors.lastname: Johnston
authors.forename: D E
authors.initials: DE
authors.lastname: Pettijohn
mesh_terms: D000818:Animals; D000912:Antibodies, Neoplasm / Q000276:immunology / Q000502:physiology*; D001932:Brain Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D001984:Bronchial Neoplasms / Q000473:pathology; D002240:Carbohydrate Sequence; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D002450:Cell Communication / Q000502:physiology; D002999:Clone Cells; D005260:Female; D005782:Gels; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000276:immunology*; D008175:Lung Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008819:Mice, Nude; D008969:Molecular Sequence Data; D009077:Mucins / Q000096:biosynthesis / Q000502:physiology*; D009361:Neoplasm Invasiveness / Q000473:pathology / Q000503:physiopathology; D009368:Neoplasm Transplantation; D009844:Oligosaccharides / Q000096:biosynthesis*; D051381:Rats; D011923:Rats, Nude; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: D000912:Antibodies, Neoplasm; D005782:Gels; D007983:Lewis Blood Group Antigens; D009077:Mucins; D009844:Oligosaccharides