In vitro analysis of the melanoma/endothelium interaction increasing the release of soluble intercellular adhesion molecule 1 by endothelial cells.
Melanoma cells constitutively release intercellular adhesion molecule 1 (ICAM-1) as soluble ICAM-1 (sICAM-1), and its levels are elevated in melanoma patients and correlate with disease progression. However, this correlation is not absolute, suggesting that specific characteristics of neoplastic cells and/or ICAM-1-positive non-neoplastic cells may influence the amounts of circulating sICAM-1. In this study, we found a weak correlation (r = 0.55; r2 = 0.3) between sICAM-1 release by 40 metastatic melanomas (36 primary cultures and 4 cell lines), and ICAM-1 expression on neoplastic cells. In addition, melanoma-secreted interleukin-1alpha (IL-1alpha) (1/40) but not vascular endothelial growth factor (VEGF) (29/40), significantly (P < 0.05) up-regulated the shedding of sICAM-1 by human umbilical vein endothelial cells (HUVEC). This was completely abolished by IL-1alpha/beta neutralizing antibodies both at the protein and mRNA level. Altogether, our results suggest that (i) the extent of sICAM-1 release is distinctive for individual melanomas and can be independent of ICAM-1 expression; (ii) tumor endothelia may sustain levels of sICAM-1 in selected melanomas; (iii) melanoma-released VEGF does not affect ICAM-1 expression and sICAM-1 release by HUVEC. Melanoma-derived sICAM-1 inhibits cell-mediated cytotoxicity of melanoma cells; therefore, constitutive levels of sICAM-1 release and IL-1alpha secretion by individual melanomas can differentially influence tumor progression and the clinical effectiveness of cytotoxic-cell-based vaccines.
Fonsatti
E
E
Advanced Immunotherapy Unit, Centro di Riferimento Oncologico, I.N.R.C.C.S., Aviano, Italy.
Lamaj
E
E
Coral
S
S
Sigalotti
L
L
Nardi
G
G
Gasparollo
A
A
Colombo
M P
MP
Altomonte
M
M
Maio
M
M
D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis* / Q000235:genetics; D007375:Interleukin-1 / Q000502:physiology; D008545:Melanoma / Q000503:physiopathology*; D012333:RNA, Messenger / Q000032:analysis; D014407:Tumor Cells, Cultured
D007375:Interleukin-1; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1