Skip to main content
Log in

Bone marrow microenvironment confers imatinib resistance to chronic myelogenous leukemia and oroxylin A reverses the resistance by suppressing Stat3 pathway

  • Organ Toxicity and Mechanisms
  • Published:
Archives of Toxicology Aims and scope Submit manuscript

Abstract

Imatinib (IM) is highly effective in treatment of chronic myeloid leukemia (CML) but does not eliminate minimal residual disease (MRD), which remains a potential source of relapse. IM treatment effectively inhibits BCR–ABL kinase activity in CML cells, suggesting that additional kinase-independent mechanisms contribute to the presence of MRD. Bone marrow (BM) microenvironment protecting CML cells from IM treatment was investigated. Culturing CML cell line K562 in human stromal cell line HS-5-derived conditioned medium significantly inhibited apoptosis induced by IM, which was soluble factor-mediated drug resistance (SFM-DR). The BM stroma-derived soluble factors could enhance the resistance of K562 cells to IM by increasing Stat3 phosphorylation on tyrosine 705 and subsequently increasing the expression of anti-apoptotic proteins and P-glycoprotein (P-gp) in K562 cells. Furthermore, the reversal effect of oroxylin A, a naturally monoflavonoid isolated from the root of Scutellaria baicalensis Georgi, in K562 cells within the SFM-DR model was detected. After treatment of weakly toxic concentration of oroxylin A, the apoptosis of K562 cells induced by IM was increased dramatically through suppressing Stat3 pathway. In addition, the in vivo study showed that oroxylin A potentiates the inhibitory effects of IM on leukemia development by suppressing Stat3 pathway in the K562 xenograft model. In conclusion, IM-induced resistance in K562 cells within the SFM-DR model correlated with increasing Stat3 signaling and upregulating P-gp expression through Stat3 pathway. Additionally, oroxylin A improved the sensitivity of K562 cells to IM in SFM-DR model and in vivo, and the underlying mechanism attributed to the suppression of Stat3 pathway, which suggested oroxylin A might be a promising agent for treatment designed to eradicate MRD in CML patients.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

Download references

Acknowledgments

This work was supported by the National Science & Technology Major Project (No. 2012ZX09103101-050 and 2012ZX09304-001), the National Natural Science Foundation of China (No. 91029744 and 81001452), Natural Science Foundation of Jiangsu Province, China (No. BK2010432), the Project Program of State Key Laboratory of Natural Medicines, China Pharmaceutical University(No. SKLNMZZJQ201302, SKLNMZZ201210), Program for Changjiang Scholars and Innovative Research Team in University (IRT1193), and Fundamental Research Funds for the Central Universities(No.JKP2013010).

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to L. Zhao or Q. Guo.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Li, X., Miao, H., Zhang, Y. et al. Bone marrow microenvironment confers imatinib resistance to chronic myelogenous leukemia and oroxylin A reverses the resistance by suppressing Stat3 pathway. Arch Toxicol 89, 121–136 (2015). https://doi.org/10.1007/s00204-014-1226-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00204-014-1226-6

Keywords

Navigation