Loss or Inhibition of Stromal-Derived PlGF Prolongs Survival of Mice with Imatinib-Resistant Bcr-Abl1+ Leukemia

SummaryImatinib has revolutionized the treatment of Bcr-Abl1+ chronic myeloid leukemia (CML), but, in most patients, some leukemia cells persist despite continued therapy, while others become resistant. Here, we report that PlGF levels are elevated in CML and that PlGF produced by bone marrow stromal cells (BMSCs) aggravates disease severity. CML cells foster a soil for their own growth by inducing BMSCs to upregulate PlGF, which not only stimulates BM angiogenesis, but also promotes CML proliferation and metabolism, in part independently of Bcr-Abl1 signaling. Anti-PlGF treatment prolongs survival of imatinib-sensitive and -resistant CML mice and adds to the anti-CML activity of imatinib. These results may warrant further investigation of the therapeutic potential of PlGF inhibition for (imatinib-resistant) CML.

► PlGF levels are elevated in human and murine CML
► Stromal cell-derived PlGF is upregulated through leukemia cell contact
► PlGF is a mitogen for leukemia cells and stimulates BM angiogenesis
► Anti-PlGF prolongs survival of imatinib-sensitive and -resistant CML mice