High expression of bcl-2 is the rule in acute lymphoblastic leukemia, except in Burkitt subtype at presentation, and is not correlated with the prognosis.
Bcl-2 expression and its prognostic value were evaluated using the APAAP technique in 40 ALL patients. Because of a possible synergy between c-myc and bcl-2 proteins in cell lines, we compared 40 ALL of either T or B lineage with seven Burkitt's ALL or sporadic Burkitt's lymphomas (BL). We found the same high expression of bcl-2 in adult (Ad) and childhood (Ch) malignancies examined at presentation, regardless of the T or B phenotype. No bcl-2 expression was detectable in BL cases, except for two investigated at relapse. Bcl-2 staining intensity was also not related to the stage of blast differentiation, except in Ad T-ALL, or to the relapse rate. Ki-67, a marker of proliferation, was used to investigate the possible correlation between bcl-2 expression and the proliferative activity. An inverse correlation was found only in BL at presentation. We confirm that bcl-2 expression is the rule in ALL, regardless of the immunophenotypic characteristics at presentation, and that high expression is not correlated with a bad prognosis. Sporadic BL may represent a particular type of tumor, with bcl-2 expression in relapse, but not at presentation.
Gala
J L
JL
Department of Hematology, Cliniques Universitaires Saint Luc, Brussels, Belgium.
Vermylen
C
C
Cornu
G
G
Ferrant
A
A
Michaux
J L
JL
Philippe
M
M
Martiat
P
P
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002051:Burkitt Lymphoma / Q000378:metabolism; D002454:Cell Differentiation; D002455:Cell Division; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011505:Protein-Tyrosine Kinases