Angiogenesis and neuroblastomas: interleukin-8 and interleukin-8 receptor expression in human neuroblastoma.
OBJECTIVE
Studies have demonstrated that the pro-angiogenic cytokine interleukin-8 (IL-8) and the IL-8 receptors likely have a role in the growth and metastasis of various solid tumors. We hypothesized that in vivo neuroblastoma expresses IL-8 and the IL-8 receptors A and B, and that factors known to regulate IL-8 expression are present and active in the neuroblastoma microenvironment.


METHODS
To confirm the presence of IL-8/IL-8 receptors in neuroblastoma, immunohistochemical analysis for IL-8 and its receptors was performed on 10 archival specimens, including benign adrenal and well to poorly differentiated neuroblastoma samples. Immunohistochemical analysis was also performed for interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha. Cultured neuroblastoma cells SK-N-MC and SK-N-SH were stimulated with 10 ng./ml. IL-1beta or tumor necrosis factor-alpha and control media (15 each). Cell culture supernatants were analyzed with enzyme-linked immunosorbant assay for IL-8 levels at 24 and 48 hours.


RESULTS
Minimal expression of IL-8 was noted in benign adrenal tissue but expression for IL-8 was present in all neuroblastoma specimens. Microvessel staining was present in 30% of the specimens. All tumor specimens expressed IL-8 receptor B, and both receptors were expressed in the tumor microvasculature. Immunohistochemical analysis confirmed the presence of IL-1beta and tumor necrosis factor in the neuroblastoma microenvironment. In vitro studies demonstrated that SK-N-MC and SK-N-SH cells express low levels of IL-8 under normal conditions and that IL-1beta and tumor necrosis factor-alpha significantly increased expression of IL-8 at 24 and 48 hours.


CONCLUSIONS
Our results indicate that IL-8 and its receptors are expressed in neuroblastoma tumor specimens. In addition, the fact that IL-1beta and tumor necrosis factor-alpha are expressed in the neuroblastoma microenvironment combined with our in vitro results suggests that these cytokines may be involved in in vivo regulation of IL-8 in human neuroblastoma. Understanding the angiogenic factors and regulatory cascade promoting angiogensis in neuroblastoma may lead to the development of effective anti-angiogenic strategies.
Ferrer
F A
FA
Department of Pediatric Urology, The Connecticut Children's Medical Center, Hartford, Connecticut 06106, USA.
Pantschenko
A G
AG
Miller
L J
LJ
Anderson
K
K
Grunnet
M
M
McKenna
P H
PH
Kreutzer
D
D
D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D016209:Interleukin-8 / Q000378:metabolism*; D009389:Neovascularization, Pathologic; D009447:Neuroblastoma / Q000098:blood supply* / Q000378:metabolism* / Q000503:physiopathology; D018123:Receptors, Interleukin / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D016209:Interleukin-8; D018123:Receptors, Interleukin; D014409:Tumor Necrosis Factor-alpha