  The ALL-1 gene is directly involved in 5-10% of ALLs and AMLs by fusion to
other genes or through internal rearrangements. DNA microarrays were utilized
to determine expression profiles of ALLs and AMLs with ALL-1 rearrangements.
These profiles distinguish those tumors from other ALLs and AMLs. The
expression patterns of ALL-1-associated tumors, in particular ALLs, involve
oncogenes, tumor suppressors, anti apoptotic genes, drug resistance genes etc.,
and correlate with the aggressive nature of the tumors. The genes whose
expression differentiates between ALLs with and without ALL-1 rearrangement
were further divided into several groups enabling separation of ALL-1-
associated ALLs into two subclasses. Further, AMLs with partial duplication of
ALL-1 vary in their expression pattern from AMLs in which ALL-1 had undergone
fusion to other genes. The extensive analysis described here draws attention to
genes which might have a direct role in pathogenesis.
