Targeting TKI-Activated NFKB2-MIF/CXCLs-CXCR2 Signaling Pathways in FLT3 Mutated Acute Myeloid Leukemia Reduced Blast Viability

Abstract

Disease relapse is a common cause of treatment failure in FMS-like tyrosine kinase 3 (FLT3) mutated acute myeloid leukemia (AML). In this study, to identify therapeutic targets responsible for the survival and proliferation of leukemic cells (blasts) with FLT3 mutations after gilteritinib (GILT, a 2nd generation tyrosine kinase inhibitor (TKI)) treatment, we performed proteomic screening of cytokine release and in vitro/ex vivo studies to investigate their associated signaling pathways and transcriptional regulation. Here, we report that macrophage migration inhibition factor (MIF) was significantly increased in the supernatant of GILT-treated blasts when compared to untreated controls. Additionally, the GILT-treated blasts that survived were found to exhibit higher expressions of the CXCR2 gene and protein, a common receptor for MIF and pro-inflammatory cytokines. The supplementation of exogenous MIF to GILT-treated blasts revealed a group of CD44High+ cells that might be responsible for the relapse. Furthermore, we identified the highly activated non-classical NFKB2 pathway after GILT-treatment. The siRNA transient knockdown of NFKB2 significantly reduced the gene expressions of MIF, CXCR2, and CXCL5. Finally, treatments of AML patient samples ex vivo demonstrated that the combination of a pharmaceutical inhibitor of the NFKB family and GILT can effectively suppress primary blasts’ secretion of tumor-promoting cytokines, such as CXCL1/5/8. In summary, we provide the first evidence that targeting treatment-activated compensatory pathways, such as the NFKB2-MIF/CXCLs-CXCR2 axis could be a novel therapeutic strategy to overcome TKI-resistance and effectively treat AML patients with FLT3 mutations.

FBP1-Altered Carbohydrate Metabolism Reduces Leukemic Viability through Activating P53 and Modulating the Mitochondrial Quality Control System In Vitro

“…AML blasts were collected for RNA isolation and qPCR analysis as previously described [ 16 ]. Total RNA was isolated using the RNeasy Mini Kit (Qiagen, Hilden, DE) according to the manufacturer’s instructions.…”

The potential role of the thymus in immunotherapies for acute myeloid leukemia

“…This process has been proposed to potentiate the increasing self-reactivity and auto-inflammation observed with aging ( 45 ). It is known that chronic inflammation can aid in tumor progression, metastasis and drug resistance in tumor cells ( 84 ), and pro-inflammatory mediators also promote the disease progression and relapse of AML ( 16 , 85 ). Accordingly, it is thus possible that the disruption in T cell homeostasis derived from thymic atrophy might play a role in AML pathogenesis.…”

The Role of CXCR1, CXCR2, CXCR3, CXCR5, and CXCR6 Ligands in Molecular Cancer Processes and Clinical Aspects of Acute Myeloid Leukemia (AML)

“…Furthermore, CXCR2 ligands induce resistance to FLT3 tyrosine kinase inhibitors. CXCR2 ligands, including MIF, increase the survival of AML cells exposed to FLT3 tyrosine kinase inhibitors such as gilteritinib [ 76 ]. Notably, gilteritinib itself activates NF-κB2, leading to increased MIF expression in AML cells.…”