lewis-x-antigen and Fibrosarcoma

Human fibrosarcoma HT1080 cell surface phenotype analysis revealed the expression of "cluster of differentiation 15" (CD15) antigen and to a lesser extent, of "very late antigen-4" (VLA-4). Expression of "endothelial-leukocyte adhesion molecule-1" (ELAM-1) was negligible on resting human umbilical vascular endothelial cells (HUVECs), but its expression could be induced by HT1080 conditioned medium. HT1080 cell adhesion to HUVECs was partially dependent on CD15/ELAM-1 adhesion molecules. HT1080 cell adhesion to HUVECs induced the enhancement of nitric oxide (NO) production from HUVECs. Exogenous NO and NO from HUVECs enhanced ELAM-1 expression on HUVECs, HT1080 cell adhesion to HUVECs, permeability of the HUVEC monolayer, and HT1080 cell invasion through the HUVEC monolayer. These enhancements were not induced by NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME). These results suggest that NO expression induced by tumor cells via the CD15/ELAM-1 adhesion system may contribute to enhancement of tumor cell adhesion to endothelial cells and hyperpermeability of the endothelium, facilitating tumor cell invasion.

Topics: Capillary Permeability; Cell Adhesion; Culture Media, Conditioned; E-Selectin; Endothelium, Vascular; Fibrosarcoma; Humans; Integrin alpha4beta1; Integrins; Lewis X Antigen; Neoplasm Invasiveness; NG-Nitroarginine Methyl Ester; Nitric Oxide; Receptors, Lymphocyte Homing; Tumor Cells, Cultured

The stage-specific embryonic Ag-1 (SSEA-1) is a carbohydrate Ag and regarded as an onco-developmental Ag. Sialyl SSEA-1 Ag, the sialylated form of SSEA-1, is frequently expressed in human cancer cells as well as in murine cancer cells. A mAb, FH-6, was shown to specifically recognize the Ag. We have generated five anti-Id Abs directed to the paratope-related idiotopes of the FH-6 Ab. One of these anti-Id Abs, Id-F2, increased the survival of host mice that were inoculated with Meth-A cells expressing the sialyl SSEA-1 Ag. To clarify the exact mechanism underlying the antitumor effect of the anti-Id Ab, we established a T cell line that recognized Id-F2 in association with MHC class II molecules. The T cell line was CD4+V beta 8+, and produced IL-2, exhibiting helper activity for B cells. The VH CDR2 region of the Id-F2 amino acid sequences turned out to be strongly immunogenic to T cells. When the immune complexes, consisting of the sialyl SSEA-1 Ag, FH-6, and Id-F2, were formed at the Meth-A cell-surface, the T cell line showed a strong proliferative response. The possible roles played by such T cell subsets in the anti-tumor effect are discussed.

Topics: Amino Acid Sequence; Animals; Antibodies, Anti-Idiotypic; Antibody Specificity; Antigen-Antibody Complex; Cell Line; Fibrosarcoma; Histocompatibility Antigens Class II; Immunization, Passive; Immunodominant Epitopes; Immunoglobulin Variable Region; Lewis X Antigen; Lymph Nodes; Lymphocyte Activation; Methylcholanthrene; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Protein Binding; T-Lymphocytes

The reactivity of monoclonal antibodies from the 5th workshop Selectins/Selectin Ligands panel, directed to the sialylated Lewis(x) and sialylated Lewis(a) determinants, with the human breast carcinoma (BT-20, ZR-75-1 and MDA-MB-468) cell lines, human ovarian carcinoma cell line A2780, fibrosarcoma (HT-1080, B-6FS) and hematopoietic neoplastic (U-937, HL-60, K-562) cell lines were determined with the aid of flow immunocytofluorometry. The examined monoclonal antibodies to sialylated Lewis determinants reacted with examined breast carcinoma, but not with the examined ovarian carcinoma and fibrosarcoma cell lines.

Topics: Antibodies, Monoclonal; Breast Neoplasms; Epitopes; Female; Fibrosarcoma; Flow Cytometry; Fluorescent Antibody Technique; Humans; Leukemia, Promyelocytic, Acute; Lewis Blood Group Antigens; Lewis X Antigen; Melanoma; Neoplasms; Ovarian Neoplasms; Tumor Cells, Cultured