Oroxylin A, a natural compound, mitigates the negative effects of TNFα-treated acute myelogenous leukemia cells

Carcinogenesis. 2018 Oct 8;39(10):1292-1303. doi: 10.1093/carcin/bgy004.

Abstract

Tumor necrosis factor alpha (TNFα) is a complicated cytokine which is involved in proliferation and differentiation of acute myelogenous leukemia (AML) cells through a poorly understood mechanism. Mechanistic studies indicate that TNFα induced binding of PI3K subunit p85α to N-terminal truncated nuclear receptor RXRα (tRXRα) proteins, and activated AKT. The activated PI3K/AKT pathway negatively regulated differentiation of AML cells through the upregulation of c-Myc. In addition, TNFα also induced activation of nuclear factor κB (NF-κB), a nuclear transcription factor which was shown to promote cell proliferation. The present study demonstrates that oroxylin A, a natural compound isolated from Scutellariae radix, sensitizes leukemia cells to TNFα and markedly enhances TNFα-induced growth inhibition and differentiation of AML cell including human leukemia cell lines and primary AML cells. Activation of PI3K/AKT pathway could be inhibited by oroxylin A through inhibiting expression of tRXRα in NB4 and HL-60-resistant cells. Furthermore, we found that oroxylin A inhibited the activation of NF-κB and the DNA binding activity by TNFα proved by EMSA in these two AML cell lines. Moreover, in vivo studies showed that treatment with oroxylin A in combination with TNFα decreased AML cell population and prolonged survival in NOD/SCID mice with xenografts of primary AML cells. Overall, our results indicate that oroxylin A is able to inhibit the negative effects of TNFα for AML therapy, suggesting that combination of oroxylin A and TNFα have the potential to delay growth or eliminate the abnormal leukemic cells, thus representing a promising strategy for AML treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Blotting, Western
  • Cell Differentiation / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Drugs, Chinese Herbal / pharmacology
  • Electrophoretic Mobility Shift Assay
  • Female
  • Flavonoids / pharmacology*
  • Fluorescent Antibody Technique
  • Humans
  • Leukemia, Myeloid, Acute / drug therapy*
  • Leukemia, Myeloid, Acute / metabolism
  • Leukemia, Myeloid, Acute / pathology
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Signal Transduction / drug effects
  • Tumor Necrosis Factor-alpha / pharmacology*

Substances

  • Antineoplastic Agents
  • Drugs, Chinese Herbal
  • Flavonoids
  • Tumor Necrosis Factor-alpha
  • 5,7-dihydroxy-6-methoxy-2-phenylchromen-4-one