MTOR and PTEN expression in non-small cell lung cancer: analysis by real-time fluorescence quantitative polymerase chain reaction and immunohistochemistry

Abstract

To detect the expression of mammalian target of rapamycin (mTOR) and PTEN in non-small cell lung cancer (NSCLC), and explore their role in the prognosis of patients with NSCLC. Samples of cancer tissues and normal lung tissues from 78 patients with NSCLC were examined for expression of mTOR and PTEN by real-time polymerase chain reaction and immunohistochemistry. The differences in mTOR and PTEN expression were compared by Student's t test. A Cox regression model was used to analyze the relationship between the influencing factors and the prognosis. Kaplan-Meier survival curves and the log-rank test were used to analyze the progression-free survival. The mTOR expression in NSCLC tissues was significantly higher than that in normal lung tissue, while the levels of PTEN expression in NSCLC tissue were significantly lower than that in normal lung tissues (P<0.05). No significant correlations were observed between the mTOR and PTEN expressions and the patients' age, sex, pathological type, differentiation, lymph node metastasis, or distant metastasis. The only correlation was with the T stage. The Cox regression analysis showed that mTOR and PTEN expression had an important impact on the patient prognosis. The absence of and/or a low expression of PTEN and activated mTOR may play an important role in the development of NSCLC, and may represent new prognostic biomarkers for a poor prognosis in patients with NSCLC.