Genomic instability at the human CD5 gene promoter

The gene coding for the human CD5 lymphocyte surface receptor maps to the 11q12.2 region, which is in the vicinity of a region commonly affected by multiple somatic mutations in human cancers. The 5'-flanking region of the human CD5 gene includes an evolutionarily conserved (TC)n(CA)n microsatellite (MS) of potential utility as a marker for genome instability. The aim of the present study was to investigate the value of the CD5 MS as a marker for instability in different tumor types, particularly in B-cell leukemia and lymphoma.

The CD5 MS and a panel of 10 MS markers were analyzed by using a polymerase chain reaction (PCR)-based method and polyacrylamide sequencing gels. This was done in several hematopoietic and non-hematopoietic cell lines, as well as in 28 cases of B-cell chronic lymphocytic leukemia (B-CLL), 19 mantle cell lymphomas (MCL) and 45 head and neck carcinomas (HNC).

The frequency of CD5 MS abnormalities found among HNC was similar to that reported for other well known MS markers at loci near known and suspected cancer genes. However, instability at the CD5 MS was the most frequent MS abnormality among B-CLL and MCL.

The inclusion of MS markers at chromosome 11q may be especially informative for genome instability analyses of certain B-cell leukemias and lymphomas.