Decreased perioxisome proliferator-activated receptor gamma gene expression was correlated with poor prognosis in patients with lung cancer

Abstract

Activation of the nuclear hormone receptor perioxisome proliferator-activated receptor gamma (PPARγ) inhibits cell growth and induces apoptosis in several human cancers. We have hypothesized that PPARγ mRNA levels could be predictors of the differentiation and survival of lung cancer. The study included 77 lung cancer cases. The mRNA levels were quantified by real time reverse transcription-polymerase chain reaction (RT-PCR) using LightCycler. The PPARγ mRNA levels were decreased in tumor tissues from lung cancer (0.579±1.255) compared to the normal adjacent lung tissues (4.191±2.868) ( P=0.0001). No significant difference in PPARγ mRNA levels was found among gender, age, and pathological subtype. The PPARγ mRNA levels were higher in tumor tissues from higher differentiated lung cancer. The NSCLC patients with low PPARγ mRNA expression (<0.5) had significantly worse survival than the patients without low PPARγ mRNA levels ( P=0.0438, Breslow–Gehan–Wilcoxon test; P=0.0168, Cox's proportional–Hazards regression model). Thus, PPARγ mRNA levels may serve as a prognostic marker in lung cancer. Using the LightCycler RT-PCR assay, the determination of PPARγ mRNA levels might provide a potential marker for treatment of lung cancer by PPARγ agonist. However, further studies and a longer follow up are needed to confirm the impact of PPARγ in the biological behavior of the tumor.