The Expression And Significance Of NDRG1in Lung Adenocarcinoma Cells And Tissues

Objective：To study the expression and significance of NDRG1in lung adenocarcinomatissue and to evaluate the effect and mechanism of NDRG1on proliferation and apoptosisof lung adenocarcinoma cells.Methods：NDRG1, P21and VEGF expressions were detected by immunohistochemistry(IHC) in20cases of normal lung tissue and in94cases of lung adenocarcinoma tissue. Thecorrelation among NDRG1, P21and VEGF expressions in lung adenocarcinoma tissue wasinvestigated by Spearman rank correlation analysis. The relationship between NDRG1expression and clinicopathological characteristics was investigated by Kaplan-Meiersurvival curve analysis. pcDNA3.0-NDRG1and pcDNA3.0were transfected into A549cells through lipofectamine and positive clones were screened by G418. Fluorescencequantitive polymerase chain reaction(qRT-PCR) and western blot were performed toidentify mRNA and protein expressions of NDRG1in A549cells respectively. Theexpressions of P21and MDM2in positive clones were detected by qRT-PCR and westernblot. The cell proliferation and apoptosis were detected by MTT assay and flowcytomertry.Results：（1） In normal lung tissue and lung adenocarcinoma tissue, the positiveimmunoreactivity rate of NDRG1were90.0%(18/20) and51.2%(49/94) respectively, P21were80.0%(16/20) and33.0%(31/94) respectively, VEGF were20.0%(4/20) and53.2%(50/94) respectively. The expressions of NDRG1and P21was negatively correlatedwith lymphatic metastasis, while the expression of VEGF was positively correlated withlymphatic metastasis. The expression of P21was positively correlated with NDRG1andthe expression of VEGF was negatively correlated with NDRG1and P21. Univariatesurvival analysis indicated that the expressions of NDRG1, P21and VEGF were associatedwith patient survival.（2） Positive clone N11with NDRG1over-expression were successfully established. Compared with non-transfected control group, the expression ofP21and the apoptosis of N11were significantly increased, however, the expression ofMDM2and the proliferation of N11were significantly decreased.Conclusion：（1）The expressions of NDRG1and P21in lung adenocarcinoma tissue weredown-regulated and the expression of VEGF in lung adenocarcinoma tissue wasup-regulated. Positive expressions of NDRG1and P21suggested that patients had a lowerrate of lymph node metastasis. NDRG1may play an important role in the development andmetastasis of adenocarcinoma of lung. The joint detection of NDRG1, P21and VEGF hadsome guiding significance to judge the prognosis of lung adenocarcinoma.（2）NDRG1transfection could effectively promote the apoptosis and inhibit the proliferation of A549cells by upregulating P21expression and downregulating MDM2expression inA549cells.