shRNA-targeted cyclooxygenase (COX)-2 inhibits proliferation, reduces invasion and enhances chemosensitivity in laryngeal carcinoma cells

Mol Cell Biochem. 2008 Oct;317(1-2):179-88. doi: 10.1007/s11010-008-9847-9. Epub 2008 Jul 1.


Cyclooxygenase-2 (COX-2), one isoform of cyclooxygenase proinflammatary enzymes, is a causal factor for tumor development, invasion, metastasis, and chemoresistance. It is frequently overexpressed in a variety of human malignancies, including laryngeal carcinoma. To investigate its possibility as a therapeutic target for the treatment of laryngeal carcinoma, we employed RNA interference technology to downregulate endogenous gene COX-2 expression in laryngeal carcinoma cells and analyzed its phenotypical changes. Results showed that shRNA-mediated downregulation of COX-2 expression in human laryngeal carcinoma cells significantly inhibited cell proliferation and colony formation in vitro and reduced the potential of tumorigenicity in vivo. The specific downregulation led to cell arrest in the G(0)/G(1) phase of cell cycle and final apoptosis induction. The increased apoptosis was associated with the ratios of Bcl-2 or Bcl-xL/Bax. In the present study, we also observed that the downregulation of COX-2 could obviously enhanced the cytotoxic effect of Taxanes both in vitro and in vivo. All these results suggest that knockdown of COX-2 expression can lead to potent antitumor activity and chemosensitizing activity to taxanes in human laryngeal carcinomas.

MeSH terms

  • Animals
  • Apoptosis
  • Caspase 3 / metabolism
  • Cell Cycle
  • Cell Line, Tumor
  • Cell Proliferation
  • Cyclooxygenase 2 / deficiency*
  • Down-Regulation
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Laryngeal Neoplasms / enzymology*
  • Laryngeal Neoplasms / genetics
  • Laryngeal Neoplasms / pathology*
  • Mice
  • Mice, Nude
  • Neoplasm Invasiveness
  • Plasmids / genetics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / metabolism*
  • Tumor Stem Cell Assay
  • Xenograft Model Antitumor Assays*


  • RNA, Messenger
  • RNA, Small Interfering
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • Caspase 3