THBS2在肺腺癌组织中的表达及其对肺腺癌细胞迁移、侵袭和上皮间质转化的影响

目的:研究血小板反应蛋白2（thrombospondin 2，THBS2）在肺腺癌组织中的表达及其对肺腺癌细胞H1299和A549迁移能力、侵袭能力、上皮间质转化（epithelial-mesenchymal transition，EMT）的影响，并探究分子机制。方法:运用TIMER和GEPIA数据库分析THBS2 mRNA在泛肿瘤和肺腺癌组织中的表达，利用UALCAN数据库分析THBS2 mRNA在I-IV期肺腺癌组织中的表达差异，通过HPA数据库检测THBS2蛋白在肺腺癌组织中的表达情况。通过免疫印迹实验（Western blot）检测THBS2在人正常支气管上皮细胞（BEAS-2B）和肺腺癌细胞（H1299、A549）中的表达情况。应用质粒转染技术在肺腺癌细胞H1299和A549中分别过表达和敲低THBS2。细胞划痕实验和侵袭实验（Transwell）检测细胞迁移和侵袭能力。Western blot验证THBS2过表达和敲低效率，同时检测EMT相关蛋白和MMP2的表达水平。结果:TIMER数据库与GEPIA数据库检索结果显示THBS2 mRNA在肺腺癌组织中高表达（P＜0.001）。UALCAN数据库分析证明，与正常肺组织相比，THBS2 mRNA在I-IV期肺腺癌组织中均显著表达（P＜0.001）。HPA数据库结果显示，THBS2蛋白在肺腺癌组织中呈现中高等强度表达。细胞划痕实验、Transwell实验和Western blot结果表明，THBS2在人正常支气管上皮细胞和肺腺癌细胞中的表达有显著差异（P＜0.01）；过表达THBS2可增加肺腺癌细胞H1299和A549迁移与侵袭能力（P＜0.01），EMT相关蛋白E-cadherin表达水平减少，而N-cadherin和Vimentin表达水平增加（P＜0.01）；相反的，敲低THBS2可抑制肺腺癌细胞H1299和A549迁移与侵袭能力（P＜0.01），EMT相关蛋白E-cadherin表达水平增加，而N-cadherin和Vimentin表达水平减少（P＜0.01）。结论:THBS2在肺腺癌组织中高表达；THBS2在肺腺癌细胞（H1299、A549）中的表达均显著高于人正常支气管上皮细胞（BEAS-2B）；THBS2在肺腺癌细胞H1299和A549中的过表达和敲低影响迁移、侵袭和EMT的过程，可作为肺腺癌治疗的新型潜在靶点。

The expression of THBS2 in lung adenocarcinoma tissues and its effect on migration,invasion and epithelial-mesenchymal transition of adenocarcinoma cells

Objective:To study the expression of thrombospondin 2 (THBS2) in lung adenocarcinoma tissues and the effect of THBS2 on the migration,invasion and epithelial-mesenchymal transition (EMT) of lung adenocarcinoma cells H1299 and A549,and to explore its molecular mechanism.Methods:The TIMER and GEPIA databases were used to analyze the expression of THBS2 mRNA in pan-tumor and lung adenocarcinoma tissues,and the UALCAN database was used to analyze the difference of THBS2 mRNA expression in stage I-IV lung adenocarcinoma tissues.The protein expression of THBS2 in lung adenocarcinoma tissues was analyzed by the HPA database.The expression of THBS2 in human normal bronchial epithelial cells (BEAS-2B) and lung adenocarcinoma cells (H1299,A549) was detected by Western blot.THBS2 was overexpressed and knocked down by plasmid transfection technology in lung adenocarcinoma cells H1299 and A549,respectively.Cell migration and invasion ability were detected by cell scratch assay and Transwell assay.Western blot was used to verify the overexpression and knockdown efficiency of THBS2,and to detect the expression levels of EMT-related proteins and MMP2.Results:The search results of TIMER database and GEPIA database showed that THBS2 mRNA was highly expressed in lung adenocarcinoma tissues (P<0.001).UALCAN database analysis showed that compared with normal lung tissues,THBS2 mRNA was significantly expressed in stage I-IV lung adenocarcinoma tissues (P<0.001).The results of HPA database showed that THBS2 protein was expressed in lung adenocarcinoma tissues with medium to high intensity.The results of cell scratch assay,Transwell assay and Western blot showed that the expression of THBS2 was significantly different between normal bronchial epithelial cells and lung adenocarcinoma cells (P<0.01).The overexpression of THBS2 could increase the migration and invasion abilities of lung adenocarcinoma cells H1299 and A549 (P＜0.01),and the expression level of EMT-related protein E-cadherin was decreased,while the expression levels of N-cadherin and Vimentin were increased (P<0.01).Conversely,knockdown of THBS2 inhibited the migration and invasion of lung adenocarcinoma cells H1299 and A549 (P<0.01),increased the expression level of EMT-related protein E-cadherin,and decreased the expression levels of N-cadherin and Vimentin (P<0.01).Conclusion:THBS2 was highly expressed in lung adenocarcinoma tissues.The expression of THBS2 in lung adenocarcinoma cells (H1299,A549) was markedly higher than that in human normal bronchial epithelial cells (BEAS-2B).Overexpression and knockdown of THBS2 in lung adenocarcinoma cells H1299 and A549 can affect the process of migration,invasion and EMT,and can be used as a new potential target for lung adenocarcinoma therapy.