Correlation between NADPH oxidase 4 and epithelial mesenchymal transformation in non-small cell lung cancer

Objective To explore the relationship between the expression of nicotinamide adenine dinucleotide oxidase 4 (NOX4) and epithelial mesenchymal transformation (EMT) in non-small cell lung cancer. Methods Collected from 2015 to 2018 in ningxia medical university general hospital by pathological diagnosis of non-small cell lung cancer patients with surgical specimens and paraffin embedding or fiber bronchoscope based tissue samples as lung cancer group (29 cases), select the same lobectomy or lung resection and admission or fiber bronchoscope lung benign lesions of organization as the control group (20 cases), immunohistochemical method is used respectively to detect lung cancer groups and control group in the lung tissue specimens NOX4, E-cadherin (E-Ca) and Vimentin expression.To analyze the relationship between NOX4 expression, tumor staging, distant metastasis and other tumor biological behaviors. Results The EMT-related marker protein Vimentin was mainly expressed in the cytoplasm, and the average optical density of the lung tissue in the lung cancer group and the control group was (26.42±8.40) and (11.66±8.30), respectively.The expression of Vimentin was higher than that in the control group, and the difference was statistically significant (t=6.078, P<0.001). E-Ca expression was mainly expressed in the cell membrane, and the average optical density of E-Ca expression in the lung cancer group and the control group was (5.15±6.67) and (14.97±7.68), respectively.E-Ca expression was lower than that in the control group, and the difference was statistically significant (t=-4.819, P<0.001). The main expression sites of NOX4 were cytoplasm and nucleus of cells.The average optical density of NOX4 expression in lung tissues of lung cancer group and control group was (29.36±11.60) and (11.27±7.36), respectively.The expression of NOX4 in lung cancer group was significantly higher than that in control group, and the difference was statistically significant (t=6.160, P<0.001). NOX4 protein expression in lung cancer group was negatively correlated with E-Ca expression (r=-0.612, P=0.001), and NOX4 expression was positively correlated with Vimentin expression (r=0.593, P=0.001). In the control group, NOX4 protein expression was not correlated with E-Ca expression (r=0.101, P=0.671), and NOX4 protein expression was not correlated with Vimentin expression (r=0.109, P=0.649). Conclusions High expression of NOX4 and EMT-related markers Vimentin and low expression of E-Ca were found in tumor tissues of NSCLC.NOX4 expression was negatively correlated with E-Ca expression, and positively with Vimentin expression.There is obvious EMT in lung cancer tissues, and NOX4 may participate in the EMT process through the oxidation-antioxidant signaling pathway. Key words: Carcinoma, non-small-cell lung; Oxidative stress; Nicotinamide adenine dinucleotide phosphate oxidase 4; Epithelial mesenchymal transformation