TNFalpha and anti-Fas antibodies regulate Ly-6E.1 expression by tumor cells: a possible link between angiogenesis and Ly-6E.1.
Angiogenic and poorly angiogenic tumor variants were obtained by an intraperitoneal inoculation of cells from clones of polyoma-virus transformed BALB/c 3T3 cells into syngeneic mice. The angiogenic tumor cells expressed a higher tumorigenicity phenotype and a higher capacity to produce artificial pulmonary metastases than cells from the poorly angiogenic tumors. The former cells expressed also significantly higher levels of the lymphocyte activation protein Ly-6E.1 than the former cells. The two types of cells did not differ in expression levels of CD44 and of a polyoma-virus specific membrane antigen. These results raise the possibility that the angiogenic phenotype is coregulated with Ly-6. The effect on Ly-6 expression of signal transduction through TNF receptors, functioning as pivotal regulators of angiogenesis was therefore studied. It was found that TNFalpha and more so antibodies against Fas down-regulate expression levels of Ly-6. This down-regulation seemed to be selective as expression levels of CD44 were not affected by this treatment.
Sagi-Assif
O
O
Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel.
Traister
A
A
Katz
B Z
BZ
Anavi
R
R
Eskenasy
M
M
Witz
I P
IP
D016475:3T3 Cells; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000950:Antigens, Ly / Q000096:biosynthesis* / Q000502:physiology; D002461:Cell Line, Transformed; D051379:Mice; D008807:Mice, Inbred BALB C; D009389:Neovascularization, Pathologic / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*; D019014:fas Receptor / Q000276:immunology / Q000502:physiology*
D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor