Homozygous deletion of the retinoblastoma gene in an acute lymphoblastic
leukemia (T) cell line
J Cheng, P Scully, JY Shew, WH Lee, V Vila and M Haas
Department of Pathology, University of California, San Diego, La Jolla
92093.
Human leukemia cell lines were examined for the status of the
retinoblastoma (RB) protein by immunoblotting analysis using antibodies
raised against the TrpE-RB fusion protein. One of 16 cell lines examined,
the T-cell acute lymphoblastic leukemia (ALL) line HSB-2, lacked the 110-Kd
RB protein. Southern blot analysis of genomic DNA extracted from HSB-2
cells showed a large homozygous deletion of the RB gene, stretching from
exon 18 beyond exon 27. Northern blot analysis showed multiple, abnormal RB
transcripts in HSB-2. A truncated protein (72 Kd) was detected with
35S-methionine labeling but not with 32P- orthophosphate labeling of the
HSB-2 cells. The genomic deletion of greater than 85 kb DNA at the RB locus
(13q14) was not detectable in the karyotype of the HSB-2 cells. Among the
16 human leukemia cell lines examined for the status of the RB gene, only
one, the HSB-2 line, showed an abnormal RB protein. Further study of
primary leukemia and lymphoma samples appears to be warranted.
Volume 75,
Issue 3,
pp. 730-735,
02/01/1990
Copyright © 1990 by The American Society of Hematology
