[Expression and clinical significance of mTOR and PTEN in non-small cell lung cancer].

BACKGROUND AND OBJECTIVE It has been proved that mTOR was an important signal transduction molecular and protein kinase regulating cell growth and proliferation, and mTOR could activate the downstream protein effector. PTEN could negatively regulate mTOR signal pathway and inhibit its activity. The aim of this study is to detect the mRNA expression levels of mTOR and PTEN gene, which are the key genes of mTOR signaling pathway in human non-small cell lung cancer (NSCLC) tissue. The relationship between mTOR signaling pathway and NSCLC is also explored. METHODS Lung cancer tissue specimens were obtained from 65 patients. Adjacent-tumor non-small cell lung cancer tissues from the 30 patients were served as control. The RT-PCR technique was used to detect the mTOR and PTEN gene expression levels. RESULTS The average mRNA expression levels of mTOR gene were significantly higher (0.23 +/- 0.16) in lung cancer than in adjacent-tumor tissue (0.12 +/- 0.09)(P < 0.01). The average mRNA expression levels of PTEN gene were (0.19 +/- 0.28) in lung cancer, while the mRNA expression levels of PTEN gene were (0.53 +/- 0.28) in adjacent-tumor tissue (P < 0.01). The levels of PTEN gene expression in non-small cell lung cancer were significantly lower than that in adjacent-tumor lung tissue. There are not significant relationship between mTOR and PTEN gene expression levels and patients' age, gender, pathological type, differentiation, lymph node metastasis, except tumor size. CONCLUSIONS The expression of mTOR is activated in NSCLC. The expression of PTEN is absent or decreased. The mTOR activated in NSCLC may be correlate with the absent or decreased of PTEN. The absent or decreased expression of PTEN and the actived mTOR may play important roles in carcinogenesis and metastasis of NSCLC.