Growth inhibition of A549 human lung carcinoma cells by beta-lapachone through induction of apoptosis and inhibition of telomerase activity

Int J Oncol. 2005 Apr;26(4):1017-23.


The objective of the present study was to investigate the effect of beta-lapachone, a quinone obtained from the bark of the lapacho tree (Tabebuia avellanedae), on the cell growth and apoptosis in human lung carcinoma cell line A549. Exposure of A549 cells to beta-lapachone resulted in growth inhibition and induction of apoptosis in a time- and dose-dependent manner as measured by hemocytometer counts, fluorescence microscopy and flow cytometry analysis. This increase in apoptosis was associated with a decrease in Bcl-2 and expression, an increase of Bax, and an activation of caspase-3 and caspase-9. beta-lapachone treatment markedly inhibited the activity of telomerase in a dose-dependent fashion. Additionally, the levels of human telomerase RNA (hTR) and c-myc expression were progressively down-regulated by beta-lapachone treatment. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of beta-lapachone.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Carcinoma / pathology*
  • Cell Proliferation
  • Dose-Response Relationship, Drug
  • Flow Cytometry
  • Humans
  • Lung Neoplasms / pathology*
  • Naphthoquinones / pharmacology*
  • Plant Extracts / pharmacology*
  • Reverse Transcriptase Inhibitors / pharmacology*
  • Tabebuia / chemistry
  • Telomerase / drug effects
  • Telomerase / pharmacology*
  • Tumor Cells, Cultured


  • Naphthoquinones
  • Plant Extracts
  • Reverse Transcriptase Inhibitors
  • beta-lapachone
  • Telomerase