Delineation of the frequently deleted region on chromosome arm 13q in B-cell non-Hodgkin's lymphoma

The loss of a specific chromosomal region provides a clue to the elucidatio n of the putative tumor suppressor gene implicated in the pathogenesis and progression of tumors. To delineate the specific region(s) involved in lymp homagenesis, we performed a survey of loss of heterozygosity for 11 polymor phic microsatellite loci scattered on variable chromosome arms. We examined 20 primary lymphoma samples, including both indolent and aggressive B-cell non-Hodgkin's lymphoma (B-NHL) and Hodgkin's disease (HD), and found a sig nificant number of B-NHLs with loss of genetic material on chromosome arm 1 3q at the RBI locus (50%; 4 of 8 informative cases for the RB1 locus). To s pecify the 13q deletion and to narrow the critical deleted region, we exami ned the same 20 lymphomas by intensive microsatellite mapping analysis usin g 12 microsatellite markers, mapping from 13q12.3 to 13q14. We confirmed th e frequent 13q14 deletion to be in the vicinity of the RB1 locus (50% of th e informative NHLs for at least 1 of 12 microsatellite loci; 5 of 10 aggres sive NHLs and 2 of 4 indolent NHLs, but none of 6 HDs) and determined a sub chromosomal region deleted in lymphoma on 13q14 defined by D13S164-D13S273, which is an overlapped region frequently lost in chronic lymphocytic leuke mia. Taken together, our data indicate that the 13q alterations are present in a wide variety of NHLs including both indolent and aggressive B-NHLs, s uggesting that loss of genetic material at chromosome band 13q14 may play a n important role in the formation or development of a wide variety of matur e lymphoid malignancies. (C) 2000 The Japanese Society of Hematology.