title: Identification of four genes in endothelial cells whose expression is affected by tumor cells and host immune status--a study in ex vivo-isolated endothelial cells.
abstract: A spontaneously metastasizing, well-defined mouse lymphoma was chosen as an in vivo model to study the effect of tumor-host interaction on gene expression in liver sinusoidal endothelial cells. Forty-nine bovine aortic endothelial cell (BAEC) genes, recently isolated by a differential screening approach of a cDNA library enriched for tumor necrosis factor-alpha (TNF-alpha) suppressed genes, were investigated. Four of these genes were finally selected because they were affected differentially by host immuno-competence, TNF-alpha, and tumor cells. Sequence analysis showed them to encode the bovine polyubiquitin (A4), elongation factor 1alpha (B2), the acidic ribosomal phosphoprotein PO (C3), and the ribosomal protein S2 (E10). Gene expression was analyzed by dot-blot or Northern blot analysis. TNF-alpha and tumor cell conditioned supernatant suppressed the genes additive in BAEC but not in other endothelial cells except for bovine capillary endothelial cells. Ex vivo-isolated liver endothelial cells of tumor-bearing syngeneic DBA/2 mice showed strong downregulation of these four genes in comparison to normal control values. In contrast, endothelial cells of tumor-bearing immuno-incompetent Balb/c (nu/nu) mice showed no downregulation but upregulation of these genes. Consistently, all four genes were also downregulated when BAEC were incubated with supernatants derived from ex vivo-isolated liver metastases from immuno-competent but not from -incompetent mice. Thus, the expression of a group of genes involved in protein translation and processing was more profoundly altered in endothelial cells in vivo than in vitro, suggesting that microenviromental factors and cell-cell and cell-matrix interactions play an important role.
authors.affiliation: Department of Internal Medicine I, University of Heidelberg, Heidelberg; and the German Cancer Research Center, Tumor Immunology Program and the Division of Biostatistics, Heidelberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Liliensiek
authors.forename: M
authors.initials: M
authors.lastname: Rocha
authors.forename: V
authors.initials: V
authors.lastname: Umansky
authors.forename: A
authors.initials: A
authors.lastname: Benner
authors.forename: J
authors.initials: J
authors.lastname: Lin
authors.forename: R
authors.initials: R
authors.lastname: Ziegler
authors.forename: P P
authors.initials: PP
authors.lastname: Nawroth
authors.forename: V
authors.initials: V
authors.lastname: Schirrmacher
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000166:cytology; D001483:Base Sequence; D001704:Biopolymers / Q000096:biosynthesis* / Q000235:genetics; D015152:Blotting, Northern; D002196:Capillaries / Q000166:cytology; D002417:Cattle; D002450:Cell Communication; D002478:Cells, Cultured; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D004730:Endothelium, Vascular / Q000378:metabolism*; D005109:Extracellular Matrix / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007121:Immunocompetence / Q000235:genetics*; D008099:Liver / Q000166:cytology; D008114:Liver Neoplasms, Experimental / Q000556:secondary; D008223:Lymphoma / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D008819:Mice, Nude; D008969:Molecular Sequence Data; D009368:Neoplasm Transplantation; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000096:biosynthesis* / Q000235:genetics; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000235:genetics; D025821:Polyubiquitin; D014176:Protein Biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D012269:Ribosomal Proteins / Q000096:biosynthesis* / Q000235:genetics; D017385:Sequence Homology; D013045:Species Specificity; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014452:Ubiquitins / Q000096:biosynthesis* / Q000235:genetics; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D001704:Biopolymers; D017077:Culture Media, Conditioned; D018076:DNA, Complementary; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D010750:Phosphoproteins; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; D014409:Tumor Necrosis Factor-alpha; D014452:Ubiquitins; C054675:ribosomal protein P0; C030004:ribosomal protein S2; D025821:Polyubiquitin