IL-7 directly modulates PIM1 and BCL6 expression via STAT5. (A) TAIL7 cells were withdrawn or not from IL-7 for 96 hours and collected for immunoblot analysis of BCL6, P-STAT5, and STAT5. (B) Data from ChIP-seq and RNA-seq were uploaded to University of California, Santa Cruz genome browser visualization tool (top 6 tracks). The browser is centered on the human BCL6 gene locus (hg19). Custom tracks are paired as control (Medium) and IL-7. ChIP STAT5 track pair represents peaks found upon STAT5 IP, and the arrow highlights a STAT5 binding peak. Input track represents control input for ChIP. RNA-seq track represents mRNA expression. Peak height is proportional to the expression. The bottom arrow in RNA-seq tracks highlights the decrease in overall BCL6 gene expression and concomitant processing of intron 1 into the mRNA. (C) IL-7-deprived TAIL7 cells were cultured for 72 hours in medium, IL-7, or IL-7 plus S5i and analyzed for P-STAT5 and PIM1. (D) Serum-starved, stably transduced HPB-ALL cells were cultured with or without IL-7 for 24 hours and analyzed for P-STAT5, PIM1, and P-Akt. Results are representative of at least 3 independent experiments.