Abstract
BACKGROUND AND OBJECTIVE: It has been proven that multidrug resistance (MDR) is the main cause of chemotherapy failure in lung cancer. Research on emergence mechanisms of MDR has great clinical significance in improving the curative efficiency of lung cancer chemotherapy. Proteins encoded by the SLC22A18 gene, which is similar to the transmembrane transporter, may influence the sensitivity of chemotherapeutics as well as the metabolism and growth of cells. In addition, these proteins probably have some effect on the development of lung cancer MDR. The aim of the present study is to investigate the expression of SLC22A18 protein in non-small cell lung cancer (NSCLC) as well as in corresponding normal lung tissue. Furthermore, the relationship between SLC22A18 expression and pathological grade and TNM stage is analyzed. METHODS: The expression of SLC22A18 was detected by EnVinsion in 96 cases with NSCLC and in corresponding normal lung tissue. Statistical analysis was performed using SPSS 17.0 statistical software. RESULTS: SLC22A18 was mainly located in cell membrane and cytoplasm. The expression level of SLC22A18 in NSCLC was significantly higher than that in normal tissue (P<0.01). The positive rates in squamous cell lung cancer and lung adenocarcinoma were 68% and 78.2%, respectively (P<0.05). Moreover, the higher expression of SLC22A18 was associated with lower histological grade and later TNM stage (P<0.05). CONCLUSION: SLC22A18 protein is overexpressed in NSCLC, and its expression is correlated with pathological grade and TNM stage. These findings provide the experimental basis for investigating the role of tumor and chemoresistance.