Additionally, our results suggest a possible implication of moderate/strong p21(Waf1) expression, loss of p27 expression, and cyclin D1 overexpression in the Richter's transformation of CLL.
Southern blot hybridization analysis failed to show evidence of bcl-1, bcl-2, c-myc proto-oncogene or retinoblastoma (Rb) tumor-suppressor gene rearrangements in these six cases of Richter's syndrome.
In conclusion, the bcl-1 locus rearranges in only about 4% of B-cell CLLs and NHLs, is predominantly rearranged in low-grade B-cell neoplasms, and does not appear to be preferentially associated with those occasional CLLs and low-grade NHLs displaying clinical aggressiveness, advanced clinical stage, or large cell transformation (Richter's syndrome).