Bcl-2, p53 and c-myc expression in juvenile dermatomyositis.
OBJECTIVE
To investigate p53, bcl-2 and c-myc expression in muscle biopsies from children affected with juvenile dermatomyositis (JDM) and to verify a possible dysregulation of programmed cell death in this autoimmune disease.


METHODS
Ten muscle biopsies of children affected with JDM were formalin fixed and paraffin embedded. After haematoxylin and eosin staining, immunohistochemistry was performed employing monoclonal antibodies, anti-p53, anti-bcl-2 and anti-myc. Two normal muscle biopsies were studied as controls.


RESULTS
In the biopsies of JDM, two different patterns of myofibers damage were observed: the first, with zones characterised by necrosis; and the second, with zones where an apoptotic process was dominant. Immunoreactivity for bcl-2 was positive in 8 out of 10 biopsies. P53 and c-myc expression were not present in any case. No relationship between the degree of bcl-2 immunostaining and the disease course or outcome was observed.


CONCLUSIONS
The over-expression of bcl-2 protein in JDM may suggest a dysregulation of apoptosis in myofibers. Further studies are required in order to better understand the role of our data in the pathogenetic pathways of the disease.
Falcini
F
F
Department of Paediatrics, University of Florence, Italy. falcini@cesit1.unifi.it
Calzolari
A
A
Generini
S
S
Pignone
A
A
Simonini
G
G
Zulian
F
F
Matucci-Cerinic
M
M
D017209:Apoptosis; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D003882:Dermatomyositis / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009336:Necrosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D016159:Tumor Suppressor Protein p53