Figure 5.

Suppressor of cytokine signaling 5 (SOCS5) negatively regulates interleukin‐7 receptor (IL7R) and JAK‐STAT signaling in BaF3 cells expressing KMT2A‐R and primary T‐cell lineage acute lymphoblastic leukemia (T‐ALL) cells. A, Immunoblotting of BaF3 cells transduced with KMT2A‐MLLT1 or KMT2A‐MLLT4 and negative control (pMSCV‐Neo) for SOCS5 and activated or total levels of JAK‐STAT proteins. B, Immunoblot analyses for IL‐7R and JAK‐STAT activation in primary T‐ALL, including 3 samples with higher and 3 samples with low/undetectable SOCS5 protein levels. C, Primary T‐ALL cells harboring KMT2A gene rearrangements (ALL‐215) were transduced with SOCS5‐expressing plasmid (SOCS5 OE) or negative control plasmid (CON). Primary T‐ALL sample (ALL‐214) was transduced with SOCS5 shRNA (SOCS5 KD1) only (due to insufficient cellular material) and scrambled negative control (NC). The cell lysates were immunoblotted for the expression of SOCS5 and IL‐7R and the levels of phosphorylated and total JAK‐STAT proteins. Representative blots are shown