Effects of retinoic acid (all-trans and 9-cis) on tumor progression in small-cell lung carcinoma

Biochem Biophys Res Commun. 1998 Jan 14;242(2):369-75. doi: 10.1006/bbrc.1997.7964.


The two stereoisomers of retinoic acid (RA), all-trans and 9-cis-RA, are regulators of cell proliferation, differentiation and apoptosis. In this study, the aim was to evaluate the effects of all-trans-and 9-cis-RA on cell growth, proliferation, and on the induction of apoptosis in the human small cell lung carcinoma (SCLC) cell lines NCI-H82 and NCI-H209. The application of various concentrations of all-trans and 9-cis-RA were able to inhibit cell growth and proliferation. Moreover, 3H-thymidine incorporation was inhibited and the number of viable cells decreased, suggesting that all-trans-RA and 9-cis-RA can inhibit cell proliferation in a dose dependent manner. Morphological examinations (light, electron and fluorescence microscopy) demonstrated that both retinoids had profound effects on the induction of apoptosis. Our investigation also showed that, compared to all-trans-RA, 9-cis-RA is a stronger inducer for the inhibition of cell growth and proliferation and that it is more effective in the induction of apoptosis in small cell lung carcinoma cells in culture.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alitretinoin
  • Apoptosis / drug effects
  • Carcinoma, Small Cell / drug therapy
  • Carcinoma, Small Cell / metabolism*
  • Cell Differentiation / drug effects
  • Cell Division / drug effects
  • Cell Survival / drug effects
  • Humans
  • Microscopy, Electron
  • Microscopy, Fluorescence
  • Thymidine / metabolism
  • Tretinoin / pharmacology*
  • Tumor Cells, Cultured


  • Alitretinoin
  • Tretinoin
  • Thymidine