Expression of Fas (APO-1/CD95) and Fas ligand (FasL) in human neuroblastoma.
METHODS
To determine the possible role of Fas/FasL system in the particularly heterogeneous behaviour of neuroblastoma (NB), we have measured the functional expression of Fas and its ligand, FasL, in primary neuroblastoma samples and cell lines by immunohistochemistry and flow cytometry.


RESULTS
Our results reveal that while Fas expression is associated with low stage and more mature tumors, heterogeneous FasL expression was mostly detected in high stage tumors, with our apparent correlation to MYCN amplification. Flow cytometric analysis of cell lines demonstrated a high expression of Fas in epithelial-type, HLA class I positive cell lines, which was lost upon activation with phorbol esters. In contrast, Fas ligand was detected in only a small subset of cell lines.


CONCLUSIONS
In some cell lines, cytotoxic assays revealed the ability of NB-associated Fas receptor to transduce an apoptotic signal upon triggering. The pattern of functional Fas/FasL expression in tumours and cell lines suggests that this system may be involved in the evasion of highly malignant neuroblastoma cells to host immune response.
Gross
N
N
Onco-hematology Unit, University Hospital, Lausanne, Switzerland. Nicole.Gross@chuv.hospvd.ch
Balmas
K
K
Beretta Brognara
C
C
Tschopp
J
J
D017209:Apoptosis; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D005729:Ganglioneuroma / Q000235:genetics / Q000378:metabolism; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D016259:Genes, myc; D006801:Humans; D019169:Jurkat Cells / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009367:Neoplasm Staging; D009447:Neuroblastoma / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D014407:Tumor Cells, Cultured / Q000187:drug effects; D019014:fas Receptor / Q000096:biosynthesis* / Q000235:genetics
C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D019014:fas Receptor