Cryptotanshinone Reverses Cisplatin Resistance of Human Lung Carcinoma A549 Cells through Down-Regulating Nrf2 Pathway

Cell Physiol Biochem. 2015;37(2):816-24. doi: 10.1159/000430398. Epub 2015 Sep 11.


Background/aims: To explore whether Nrf2 was associated with drug-resistance in cisplatin resistant A549 (A549/DDP) cells, and if cryptotanshinone (CTS), one of the bioactive compounds isolated from the roots of Salvia miltiorrhiza Bunge (Danshen), could enhance the sensitivity in A549/DDP cells towards cisplatin.

Methods: A549 and A549/DDP cells were subjected to various treatments, and then Sulforhodamine B (SRB) assay, flow cytometry analysis and western immunoblotting analysis were applied to determine IC50, apoptotic status and expressions of Nrf2 and its downstream genes.

Results: The endogenous expression levels of Nrf2 as well as its target genes including GCLC, GCLM, HO-1, NQO1 and MRP1 were much higher in A549/DDP cells than those of A549 cells and the susceptibility of A549/DDP cells to cisplatin was partially restored by silencing Nrf2. The combination of CTS and cisplatin led to cell death and apoptosis through sensitizing A549/DDP cells towards cisplatin compared with cisplatin mono-treatment, however, this reversal role could be abolished by Nrf2 knockdown. Specifically, CTS obviously diminished Nrf2 expression, thus contributing to the decrease of Nrf2-target genes expression levels. Meanwhile, we also discovered that CTS triggered several other signals involving in chemoresistance such as MAPKs, Akt and STAT3 pathway.

Conclusion: Our data indicated CTS may be developed as a potential sensitizer cooperating with anticancer drugs to combat chemoresistant carcinoma through the inhibition of the Nrf2 pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cisplatin / pharmacology
  • Down-Regulation
  • Drug Resistance, Neoplasm / drug effects*
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / metabolism*
  • NF-E2-Related Factor 2 / metabolism*
  • Phenanthrenes / pharmacology*
  • Signal Transduction / drug effects*


  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • Phenanthrenes
  • cryptotanshinone
  • Cisplatin