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.
背景与目的: 已有的研究证明：多药耐药（multidrug resistance, MDR）是肺癌化疗失败的主要原因，研究MDR的产生机制对于提高肺癌的化疗疗效有着重要的临床意义。SLC22A18基因编码蛋白与跨膜转运体相似，影响药物敏感性、细胞代谢和生长，可能在肺癌MDR的产生中发挥一定作用。本研究旨在检测SLC22A18在非小细胞肺癌（non-small cell lung cancer, NSCLC）及相应正常组织中的表达，并分析其与组织学类型、分级和TNM分期的关系。
方法: 应用免疫组化EnVinsion法检测SLC22A18在96例NSCLC及正常组织中的表达，结果用统计学软件SPSS 17.0进行分析。
结果: SLC22A18主要定位于胞膜和胞质中。SLC22A18在NSCLC中的表达高于正常组织，差异明显（P＜0.01），鳞癌、腺癌阳性率分别为68.0%和78.2%，差异性有统计学意义（P＜0.05）。鳞癌、腺癌不同病理分级、TNM分期间SLC22A18表达差异性均有统计学意义，癌组织分化越差、分期越晚，SLC22A18表达越高（P＜0.05）。
结论: SLC22A18在NSCLC组织中高表达，表达的高低与组织学类型、分级、TNM分期有关，本研究为进一步探讨SLC22A18在肿瘤中的表达及可能的耐药作用提供了实验依据。