Expression of CD10 by B-chronic lymphocytic leukemia cells undergoing apoptosis in vivo and in vitro.
OBJECTIVE
B-cell chronic lymphocytic leukemia (B-CLL) is an accumulating disease of slowly proliferating cells. CD10 is not normally expressed on the surface of B-CLL cells. The aim of this study was to ascertain whether B-CLL cells, induced into apoptosis, expressed surface CD10, since a correlation between apoptosis and CD10 expression has been demonstrated.


METHODS
Peripheral blood cells from 31 untreated B-CLL patients were induced into apoptosis by etoposide, fludarabine or Ga(mu)-Ab treatment and tested for CD10 expression by flow cytometry. Normal CD5+ B cells were also induced into apoptosis and tested for CD10 expression.


RESULTS
CD10 positive cells were absent in B-CLL cell suspensions, but were detected following in vitro culture, and their appearance paralleled that of apoptotic cells. Treatment with etoposide, fludarabine or Ga(mu)-Ab enhanced both apoptosis and CD10 expression. Inhibition of apoptosis by VAD-fmk or Ga(delta)-Ab prevented CD10 expression. Cell separation tests following induction of apoptosis demonstrated that CD10+ cells were apoptotic. CD10+ cells were observed in the peripheral blood of two patients within a few hours following fludarabine infusion. In another patient, who failed to respond, no CD10+ cells were seen. Expression of CD10 was observed also in normal CD5+ B cells when these were induced into apoptosis.


CONCLUSIONS
This study demonstrates that B-CLL cells, as well as normal CD5+ B cells, become CD10+ following apoptosis induction in vitro. Some of the data obtained also suggest a use for CD10 to monitor apoptosis of B-CLL in a clinical setting.
Morabito
Fortunato
F
Dipartimento di Ematologia Azienda, Ospedaliera Bianchi-Melacrino, Reggio Calabria, Italy.
Mangiola
Massimo
M
Rapezzi
Davide
D
Zupo
Simona
S
Oliva
Bianca Maria
BM
Ferraris
Anna Maria
AM
Spriano
Mauro
M
Rossi
Edoardo
E
Stelitano
Caterina
C
Callea
Vincenzo
V
Cutrona
Giovanna
G
Ferrarini
Manlio
M
D036541:ADP-ribosyl Cyclase / Q000276:immunology / Q000378:metabolism; D051997:ADP-ribosyl Cyclase 1; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000906:Antibodies / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D001402:B-Lymphocytes / Q000737:chemistry / Q000378:metabolism; D045744:Cell Line, Tumor; D005047:Etoposide / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000494:pharmacology; D007072:Immunoglobulin D / Q000494:pharmacology; D007075:Immunoglobulin M / Q000494:pharmacology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008562:Membrane Glycoproteins; D015260:Neprilysin / Q000096:biosynthesis*; D014066:Palatine Tonsil; D014740:Vidarabine / Q000031:analogs & derivatives* / Q000494:pharmacology
D000590:Amino Acid Chloromethyl Ketones; D000906:Antibodies; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D007070:Immunoglobulin A; D007072:Immunoglobulin D; D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D005047:Etoposide; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1; D015260:Neprilysin; D014740:Vidarabine; C024352:fludarabine