The Relationship Between Epidermal Growth Factor Receptor And Autophay In Lung Adenocarcinoma

Objective:The present study is divided into two parts,the first part,to investigate the relationship between the epidermal growth factor receptor(EGFR)expression and autophagy in lung adenocarcinoma A549 cells on the basic cells experiment.The second part,in clinical trials,to study whether autophagy activity is related to the EGFR mutations in patients' pleual effusion.Here is a detailed introdution.1 Studies has shown that lung cancer is a worldwide cancer,which has high morbidity and mortality.We investigate the role of EGFR in autophagy activity,by small interference RNA which could silence the expression of EGFR in lung adenocarcinoma cells(A549 cells).Here,we hope to provide some new potential theraputic strategies in lung cancer cells and offer some date and evidence for clinic and fundamental experiment for the treatment of RNA interference.2 To study the differences of autophagic protein LC3 and Beclin1 between the EGFR mutations pleual effusion group and the non-muant one from lung cancer patients by Real Time RT-PCR.Methods:The first part1 Real Time RT-PCR and Western-Blot were used to detect the degradat ion of EGFR by the transfection of exgenous specific small interference RNA(EGFR si RNA),which could slience the EGFR gene expression.2 Western-Blot was applied to detect the expression of autophagic protein LC3 after the transfection of specific small interfernce(EGFR si RNA),and discuss the relationship of EGFR and autophagy.3 Transmission electron microscopy(TEM)was utilized to observe the formation of autophagosome after the transfection of EGFR siRNA or control siRNA.The second partPleural effusion of lung cancer cells was collected by centrifugation to obtain cell sediment in China-Japen Friendship Center for Cancer Detection in Fourth Hospital of Hebei Medical Univercity from September 2015 to December 2015.1 Hematoxylin-eosin staining(HE staining)was performed for the Initial diagnosis of pleural effusion cells.2 Immunocytochemistry(ICC)was used to idetify the type and original of cancer cells.3 The EGFR gene of pleural effusion cells were detected by amplification refractory mutationsystem PCR(ARMS-PCR),which could rapidly and sensitively screen for the EGFR mutation.4 The essential autophagy effector LC3 and Beclin1 of pleural effusion cells were detected by Real Time RT-PCR.Result:The first part1 After treatment of lung adenocarcinoma A549 cells with the three different EGFR siRNAs,the mRNA and protein expression of EGFR were singnificant reduction.Among the three different siRNAs,EGFR siRNA-1 had the most significant effect of suppressing.2 Western-Blot indicated that increased LC3-?/ LC3-?ratio induced by down-regulation of EGFR.3 Transmission electron microscopy was carried out to observe that EGFR siRNA treatment,compared with control siRNA treatment,induced marked formation of autophagsomes.The second part1 By optical microscope,there were rich cells in pleural effusion smears,which demonstrated obviously different and abnormal cell morphology,increased nucleoplasm ratio and rough cell nucleus.2 By Immunocytochemical staining,the pleural effusion smears were idetified with lung adenocarcinoma,envidenced by TTF-1 positive and NapsinA positive cells.3 Amplification refractory mutationsystem PCR(ARMS-PCR)indicated 25 EGFR mutated cases and 15 EGFR non-mutated cases among 40 pleural effusion cases of lung adenocarcinoma.4 Real Time RT-PCR indicated that the expression of autophagic protein LC3 had significant difference,but the one of Beclin1 had not.Conclusions :1 EGFR special siRNA has play a significant role in the silencing of post-transcriptional gene expression.2 Decreased EGFR expression results in marked autophagy induction.3 There are significant difference of autophagy between two groups of EGFR mutated and EGFR non-mutated of pleural effusion of lung adenocarcinoma.Compared with EGFR mutants,lung adenocarcinoma cells with EGFR non-mutation has increased autophagy.4 The two parts of sdudies show,the autophagy activity of lung adenocarcinoma cells is not only related to EGFR expression,but also to the EGFR mutatons.