Induction of miR-21-PDCD4 signaling by tungsten carbide-cobalt nanoparticles in JB6 cells involves ROS-mediated MAPK pathways

Lichao Hou, Linda Bowman, Terence G. Meighan, Xianglin Shi, Min Ding

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Tungsten carbide-cobalt (WC-Co) nanoparticle composites have wide applications because of their hardness and toughness. WC-Co was classified as "probably carcinogenic" to humans by the International Agency for Research on Cancer (IARC) in 2003. It is believed that the toxicity and carcinogenesis of WC-Co is associated with particle size. Recent studies demonstrated that the tumor suppressor gene programmed cell death 4 (PDCD4) and its upstream regulator miR-21 have been considered as oncogenes for novel cancer prevention or anticancer therapies. The present study examined the effects of WC-Co nanoparticles on miR-21-PDCD4 signaling in a mouse epidermal cell line (JB6 P+). The results showed that (i) exposure of JB6 cells to WC-Co stimulated a increase of miR-21 generation; (ii) WC-Co also caused inhibition of PDCD4, a tumor suppressor protein and downstream target of miR-21, expression in JB6 cells; (iii) inhibition of ERKs with ERK inhibitor U0126 significantly reversed WCCo- induced PDCD4 inhibition, but inhibition of p38 with p38 inhibitor SB203580 did not; and (iv) ROS scavengers, N-acetyl-L-cysteine and catalase, blocked the inhibitory effect of WC-Co on PDCD4 expression, while superoxide dismutase promoted the inhibitory effect. These findings demonstrate that WC-Co nanoparticles induce miR-21 generation, but inhibit PDCD4 production, which may be mediated through ROS, especially endogenous H2O2, and ERK pathways. Unraveling the complex mechanisms associated with these events may provide insights into the initiation and progression of WC-Co-induced carcinogenesis.

Original languageEnglish
Pages (from-to)41-51
Number of pages11
JournalJournal of Environmental Pathology, Toxicology and Oncology
Issue number1
StatePublished - 2013


  • Cell signal pathways
  • JB6 cells
  • Nanoparticles
  • Nanotoxicology
  • Occupational exposure
  • Occupational respiratory disease
  • Oncogenicity
  • PDCD4
  • Tungsten carbide-cobalt
  • microRNA 21

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Toxicology
  • Health, Toxicology and Mutagenesis


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