title: Inhibition of VLA-4 and up-regulation of TIMP-1 expression in B16BL6 melanoma cells transfected with MHC class I genes.
abstract: The effect of MHC class I gene transfection on the metastatic properties of B16BL6 melanoma cells was investigated. BL6-8 melanoma cells transfected with H-2Kb or H-2Kd, but not H-2Dd or H-2Ld, genes showed a dramatic reduction in their ability to generate experimental metastases in immunosuppressed CB6F1 mice. This observation suggested that some changes in the metastatic phenotype may have been induced in the H-2K- transfected melanoma cells. Analyses of adhesive and invasive properties of BL6-8 melanoma cells transfected with H-2 class I genes have been performed. We found that the loss of metastatic properties in the H-2Kb or H-2Kd gene-transfected melanoma cells was associated with reduced adherence to endothelial cells, laminin and collagen IV, decreased ability to form homotypic cell aggregates and with a complete loss of VLA-4 integrin expression. In addition, BL6-8 melanoma cells transfected with H-2K genes demonstrated reduced ability to invade Matrigel that paralleled up-regulation of TIMP-1 expression. Incubation of untransfected BL6-8 clone or B16F1 cells with 5-azacytidine similarly resulted in up-regulation of TIMP-1, suggesting that the changes in methylation of TIMP-1 gene could be responsible for TIMP-1 expression in the H-2K-transfected BL6-8 melanoma cells. Transfection of BL6-8 cells with the H-2Dd/Ld genes did not affect their adhesive and invasive properties. Previously we reported that reduction in the metastatic properties of the H-2Kb transfected cells was associated with alterations in cell surface carbohydrates with appearance of alpha-galactosyl epitopes and reduction in cell surface sialylation. The present data indicate that, in addition to changes in cell surface carbohydrates, reduction in adhesive properties and up-regulation of TIMP-1 may be responsible for the observed loss of metastatic potential of BL6-8 cells transfected with the H-2K genes.
authors.affiliation: University of Pittsburgh Cancer Institute and Department of Pathology, University of Pittsburgh, PA 15213, USA.
authors.forename: F
authors.initials: F
authors.lastname: Xu
authors.forename: T
authors.initials: T
authors.lastname: Carlos
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: O
authors.initials: O
authors.lastname: Sanchez-Sweatman
authors.forename: R
authors.initials: R
authors.lastname: Khokha
authors.forename: E
authors.initials: E
authors.lastname: Gorelik
mesh_terms: D000818:Animals; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D005805:Genes, MHC Class I; D006183:H-2 Antigens / Q000235:genetics; D039041:Integrin alpha4beta1; D016023:Integrins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics; D008545:Melanoma / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D016201:Receptors, Lymphocyte Homing / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis* / Q000235:genetics; D014162:Transfection / Q000235:genetics*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation / Q000235:genetics*
chemical_list: D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D039041:Integrin alpha4beta1; D016023:Integrins; D016201:Receptors, Lymphocyte Homing; D019715:Tissue Inhibitor of Metalloproteinase-1