B-cell chronic lymphocytic leukemia (B-CLL) samples were screened for
alterations in multiple tumor suppressor genes (p53 (17p13), p16(INK4)
(9p21), and disrupted in B-cell malignancy (DBM) (13q14)) by using po
lymerase chain reaction-based assays. Eleven percent (11 of 96) of the
B-CLL cases analyzed in this study and a previous study had mutations
in the p53 gene. In contrast, analysis of the p16 gene showed none of
80 B-CLL cases had mutations and five cases (6%) had homozygous delet
ions. Deletions of 13q14 (DBM) occurred in 18% (17 of 96) of patients
surveyed. Thus, 28 of 96 cases showed an alteration in one or more of
the three tumor suppressor loci examined. However, cases with p53 muta
tions rarely showed simultaneous loss of DBM. Our results suggest that
inactivation of the tumor suppressor genes p53 and DBM may be mutuall
y exclusive, thus providing alternate pathways for tumor development i
n B-CLL patients. (C) 1995 Wiley-Liss, Inc.