N,N'-dinitrosopiperazine--mediated heat-shock protein 70-2 expression is involved in metastasis of nasopharyngeal carcinoma

PLoS One. 2013 May 7;8(5):e62908. doi: 10.1371/journal.pone.0062908. Print 2013.

Abstract

N,N'-Dinitrosopiperazine (DNP) is invovled in nasopharyngeal carcinoma (NPC) development and metastasis, and it shows organ specificity to the nasopharyngeal epithelium. Herein, we demonstrate that DNP induces heat-shock protein (HSP) 70-2 expression in NPC cells (6-10B) at a non-cytotoxic concentration. DNP induced HSP70-2 expression in a dose- and time- dependent manner, but showed no effect on other HSP70 family members. Furthermore, DNP also increased HSP70-2 RNA transcription through directly binding to the hypoxia-responsive elements (HRE) and heat shock elements (HSE) located in the HSP70-2 promoter. DNP-mediated HSP70-2 expression might act through enhancing the transcription of HSP70-2 RNA. Importantly, DNP induced motility and invasion of 6-10B cells dose- and time-dependently, and DNP-mediated NPC metastasis was confirmed in nude mice, which showed high HSP70-2 expression in the metastatic tumor tissue. However, the motility and invasion of NPC cells that were stably transfected using short interfering RNA against HSP70-2 could not effectively induce DNP. These results indicate that DNP induces HSP70-2 expression through increasing HSP70-2 transcription, increases the motility and invasion of cells, and promotes NPC tumor metastasis. Therefore, DNP mediated HSP70-2 expression may be an important factor of NPC-high metastasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinogens / pharmacology*
  • Carcinoma
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Dose-Response Relationship, Drug
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects*
  • HSP70 Heat-Shock Proteins / genetics*
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Nasopharyngeal Carcinoma
  • Nasopharyngeal Neoplasms / genetics*
  • Nasopharyngeal Neoplasms / pathology*
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Nitrosamines / pharmacology*
  • Promoter Regions, Genetic / drug effects
  • Time Factors
  • Transcriptional Activation / drug effects

Substances

  • Carcinogens
  • HSP70 Heat-Shock Proteins
  • Nitrosamines
  • N,N'-dinitrosopiperazine

Grants and funding

This work was in part supported by the National Natural Science Foundation of China (81071718,81000881 and 30973400), Fundamental Research Funds for the Central Universities (21611612), and Foundation of State Key Laboratory of Oncology in South China (HN2011-04). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.