Combined antitumor activity of cucurbitacin B and docetaxel in laryngeal cancer

Eur J Pharmacol. 2008 Jun 10;587(1-3):78-84. doi: 10.1016/j.ejphar.2008.03.032. Epub 2008 Apr 1.

Abstract

Combination therapy with multiple drugs is a common practice in the treatment of cancer. The promising clinical activity of docetaxel has promoted considerable interest in combining it with other antitumor agents. To determine whether cucurbitacin B can enhance chemosensitivity to docetaxel in laryngeal cancer, in the present study, we investigated the combined antitumor effect of cucurbitacin B with docetaxel on Hep-2, a human laryngeal cancer cell line. We treated Hep-2 cells with cucurbitacin B alone or in combination with docetaxel and evaluated cell growth, cell cycle distribution, and apoptosis using MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) assay, flow cytometry, and fluorescent microscopy. Our results showed that, in comparison with single agent treatment, the combination of cucurbitacin B and docetaxel produced greater efficacy in growth inhibition, cell cycle arrest at G2/M phase, and apoptosis induction. Measuring the modulation of regulators in the cell cycle, apoptosis and signal transductions by Western blot analysis showed that the combination effect of cucurbitacin B and docetaxel was due to suppress the expression of p-STAT3 (signal transducers and activators of transcription 3), Bcl-2, and cyclin B1. Moreover, our in vivo studies were reproduced in a mouse xenograft model, where, the combination of cucurbitacin B with docetaxel synergestively inhibited tumor growth. Together, this investigation suggests that cucurbitacin B combined with docetaxel may be a feasible strategy to enhance the effects of chemotherapy in patients with laryngeal cancer.

MeSH terms

  • Annexin A5 / metabolism
  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Apoptosis / drug effects
  • Apoptosis / physiology
  • Blotting, Western
  • Cell Cycle Proteins / biosynthesis
  • Cell Cycle Proteins / genetics
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Docetaxel
  • Dose-Response Relationship, Drug
  • Humans
  • Indicators and Reagents
  • Laryngeal Neoplasms / drug therapy*
  • Laryngeal Neoplasms / metabolism
  • Laryngeal Neoplasms / pathology
  • Microscopy, Fluorescence
  • Neoplasm Proteins / biosynthesis
  • Neoplasm Proteins / genetics
  • Neoplasm Transplantation
  • Signal Transduction / drug effects
  • Taxoids / pharmacology*
  • Triterpenes / pharmacology*
  • Xenograft Model Antitumor Assays

Substances

  • Annexin A5
  • Antineoplastic Agents, Phytogenic
  • Cell Cycle Proteins
  • Indicators and Reagents
  • Neoplasm Proteins
  • Taxoids
  • Triterpenes
  • cucurbitacin B
  • Docetaxel