Growth inhibition and induction of apoptosis by fenretinide in small-cell lung cancer cell lines

J Natl Cancer Inst. 1995 Nov 15;87(22):1674-80. doi: 10.1093/jnci/87.22.1674.

Abstract

Background: Lung cancer is the major cause of cancer-related death in the United States, with small-cell lung cancer (SCLC) constituting approximately 20% of all cases of lung cancer. Numerous epidemiologic and molecular studies have suggested that alterations in retinoid-signaling pathways play a role in the pathogenesis of lung cancer. Fenretinide [N-(4-hydroxyphenyl)retinamide; HPR] is a synthetic retinoid with minimal toxicity and favorable pharmacokinetics during long-term administration to patients in clinical trials.

Purpose: The aim of this investigation was to study the effect of HPR on the growth of SCLC cells in vitro.

Methods: Seven SCLC cell lines (NCI-H69, NCI-H82, NCI-H146, NCI-H209, NCI-H345, NCI-H446, and NCI-H510A) were exposed continuously to a broad range of concentrations of HPR or all-trans-retinoic acid (RA), and cell viability was determined on day 3 and day 7 by the trypan blue dye exclusion assay. The growth of these cells was compared with that of control vehicle-treated cells to determine survival fraction and the dose resulting in a 50% inhibition of growth when compared with growth of control cells (IC50). The induction of apoptosis was evaluated by fluorescent microscopy, DNA content analysis, and a terminal deoxyribonucleotidyl transferase-based assay that labels 3'-hydroxyl ends of DNA fragments (TUNEL assay) combined with flow cytometric analysis.

Results: HPR inhibited growth of a panel of SCLC cell lines at IC50 values that ranged from 0.1 to 3.0 microM (concentrations that are clinically achievable). In all cell lines tested, HPR was a more potent growth inhibitor than RA. By use of fluorescent microscopy, HPR was found to induce morphologic changes consistent with apoptosis in NCI-H82 SCLC cells, including cellular shrinkage, chromatin condensation, and nuclear fragmentation. Flow cytometric analysis revealed decreased DNA content, and TUNEL assay showed increased digoxigenin-uridine triphosphate incorporation in HPR-treated NCI-H82 SCLC cells; these findings are consistent with the induction of apoptosis.

Conclusions: HPR inhibited the in vitro growth of SCLC cells. In NCI-H82 cells, HPR inhibited growth via the induction of apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anticarcinogenic Agents / pharmacology*
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Carcinoma, Small Cell / drug therapy*
  • Carcinoma, Small Cell / genetics
  • Carcinoma, Small Cell / physiopathology
  • Cell Survival / drug effects
  • DNA, Neoplasm
  • Fenretinide / pharmacology*
  • Flow Cytometry
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / genetics
  • Lung Neoplasms / physiopathology
  • Microscopy, Fluorescence
  • Tumor Cells, Cultured

Substances

  • Anticarcinogenic Agents
  • Antineoplastic Agents
  • DNA, Neoplasm
  • Fenretinide