Reintroduction of A20 induces apoptosis in the lymphoma cell lines with A20 deletion. The oncosuppressive effects of A20 on MCL and DLBCL lymphoma cell lines infected with a lentivirus, expressing both A20 and Venus or Venus only as control. (A) Genomic profiles of analyzed lymphoma cell lines. Dots represent the log2 ratios of BAC/PAC clones, which are shown in order from chromosome band 6q centromere to 6q telomere. The location of A20 is indicated with an arrow. (B) Western blot analysis for comparison of A20 expression in human peripheral B cells treated with anti-IgM and in lymphoma cell lines. All cell lines with A20 transduction by a lentiviral vector showed high expression levels for the A20 protein. Infection efficiency of each cell line is shown in supplemental Figure 7. (C) Overexpression of A20 induced repression of NF-κB activity in lymphoma cell lines with A20 deletion as measured with a lentiviral reporter assay. In contrast, NF-κB activity is not affected by overexpression of A20 in Raji. The findings of triplicate experiments are presented as mean ± SD. NC indicates negative control; VC, vector-only control. Effect of A20 overexpression on apoptosis correlates well with NF-κB-inhibiting effect. (D) The findings of representative apoptosis assay measured by annexin V staining. (E) Triplicate experiments are presented as mean ± SD.