¹First Department of Internal Medicine, Gunma University School of Medicine, Maebashi 371-8511, Japan

²Institute for Molecular and Cellular Regulation, Gunma University School of Medicine, Maebashi 371-8511, Japan

Correspondence to: M Mori, First Department of Internal Medicine, Gunma University School of Medicine, Maebashi 371-8511, Japan. E-mail: mmori@med.gunma-u.ac.jp

Activation of peroxisome proliferator-activated receptor (PPAR)- by the thiazolidinedione (TZD) class of antidiabetic drugs elicits growth inhibition in a variety of malignant tumors. We clarified the effects of TZDs on growth of human non-small cell lung carcinoma (NSCLC) cells that express endogenous PPAR-. Troglitazone and pioglitazone caused inhibition of cellular growth and induced apoptosis of NSCLC cells in a time- and dose-dependent manner. Subtraction cloning analysis identified that troglitazone stimulated expression of the growth arrest and DNA-damage inducible (GADD)153 gene, and the increased expression of GADD153 mRNA was also confirmed by an array analysis of the 160 apoptosis-related genes. Western blot analysis revealed that troglitazone also increased GADD153 protein levels in a time-dependent manner. Troglitazone did not stimulate GADD153 mRNA levels in undifferentiated 3T3-L1 cells lacking PPAR- expression, whereas its induction was clearly observed in differentiated adipocytes expressing PPAR-. Activity of the GADD153 promoter occurred in a NSCLC cell line in transient transcription assays and was significantly stimulated by troglitazone, although binding of PPAR/retinoid X receptor heterodimer was not detected in the promoter region in gel retardation assays. Inhibition of GADD153 gene expression by an antisense phosphorothionate oligonucleotide attenuated the troglitazone-induced growth inhibition. These findings collectively indicated that activation of PPAR- by TZDs could cause growth inhibition and apoptosis of NSCLC cells and that GADD153 might be a candidate factor implicated in these processes.

Oncogene (2002) 21, 2171-2180 DOI: 10.1038/sj/onc/1205279

PPAR-; thiazolidinediones; GADD153; apoptosis; lung carcinoma