Figure 4.

E2F2 is a transcriptional target of MSC^wt that inhibits the cell cycle in ALCL cells. (A) ChIP-seq in Karpas 299 cells showed binding of MSC^wt, but not MSC^E116K, to several sites upstream and downstream of the E2F2 transcriptional start site. NR_110799 represents an uncharacterized noncoding RNA gene, LOC101928163, which was not expressed at the RNA level in any of the samples. The data shown are from the same ChIP-seq experiment as the motif analysis shown in Figure 2E. (B) Corresponding RNAseq data showed a 4.7-fold induction of E2F2 expression in Karpas 299 cells transduced with MSC^wt compared with vector-only control that was largely reversed by MSC^E116K. Representative results from 2 independent experiments. (C) ChIP in normal T cells confirmed MSC^wt binding to E2F2. (D) Overexpression of E2F2 in Karpas 299 cells, which have low basal levels of MSC and E2F2, inhibited cell cycle progression via G1 arrest. (E) MSC^E116K increased E2F reporter activity in luciferase assays, consistent with its ability to block expression of repressive E2F2. Data reflect 3 independent experiments and are shown as mean ± SD. The Student t test was used to compare results. RPKM, reads per kilobase of transcript per million mapped reads.