In situ expression of protooncogenes and Fas/Fas ligand in rheumatoid arthritis synovium.
OBJECTIVE
To examine the relationship among the expression of protooncogenes such as c-fos and c-myc, Fas antigen, Fas ligand, and apoptosis in the synovial tissue of patients with rheumatoid arthritis (RA).


METHODS
The expression of c-fos, c-myc, Fas antigen, and Fas ligand was examined in synovial tissues of 6 patients with RA and 4 with osteoarthritis (OA) using in situ reverse transcriptase (RT) assay and immunohistochemical staining. Apoptosis was detected by TUNEL method in situ.


RESULTS
Expression of protooncogenes, c-fos, and c-myc was detected in all samples from patients with RA, but in only a few cells of OA synovium. 30 to 90% of cells in RA synovium positive for these protooncogenes also coexpressed Fas antigen. Fas positive cells in RA synovium underwent apoptosis to a significant degree. Fas ligand mRNA was detected only in mononuclear cells in RA synovium.


CONCLUSIONS
The expression of protooncogenes is closely related to Fas mediated apoptosis in RA synoviocytes.
Asahara
H
H
Division of Rheumatology and Immunology, Institute of Medical Science, St. Marianna University School of Medicine, Kawasaki, Japan.
Hasunuma
T
T
Kobata
T
T
Inoue
H
H
Muller-Ladner
U
U
Gay
S
S
Sumida
T
T
Nishioka
K
K
D000368:Aged; D017209:Apoptosis / Q000502:physiology; D001172:Arthritis, Rheumatoid / Q000235:genetics*; D053222:Fas Ligand Protein; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008875:Middle Aged; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics*; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D013583:Synovial Membrane / Q000166:cytology / Q000276:immunology; D019014:fas Receptor / Q000235:genetics
C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D019014:fas Receptor