The Expression Of PEBP4 Protein In Lung Squamous Cell Carcinoma And Its Implications

PEBP4 is a member of the phosphatidylethanolamine-binding protein family.It not only plays a role in the inhibition of the MAPK signaling pathway but is also involved in the inhibition of the JNK pathway that promotes the activation of AKT.Recent research has also shown that overexpression of PEBP4 was related to the development,invasion and metastasis of a variety of tumors.This study aimed to investigate the correlation between PEBP4 protein expression in lung squamous cell carcinoma tissue and the clinical pathology of lung squamous cell carcinoma.Methods:Immunohistochemistry was used to detect PEBP4 expression in lung squamous cell carcinoma tissue and adjacent normal tissue from 61 patients.Western blotting was used to detect changes in the expression of PEBP4 protein between lung squamous cell carcinoma tissue and adjacent normal tissues.The correlation of PEBP4 expression and the occurrence,development and clinical pathology of lung squamous cell carcinoma was analyzed.Results:Of 61 patients,4 patients were PEBP4 negative(-)(6.6%)and 57 patients were positive(+ to +++)(93.4%).Of those positive for PEBP4 expression,7 patients were weakly positive(+)(11.5%),21 patients were positive(++)(34.4%)and 29 patients were strongly positive(++?)(47.5%).PEBP4 protein was more highly expressed in lung squamous cell carcinoma tissue than in the adjacent normal lung tissue(p<0.05).In PEBP4-positive patients,PEBP4 protein expression was significantly greater in those with lymph node metastases than in those without(p<0.05).PEBP4 expression was significantly lower in patients at early(?,?)stages than in patients at advanced(?,?)stages(p<0.05).In less differentiated lung squamous cell carcinomas,PEBP4 protein expression was greater(p<0.05);however,this was unrelated to the gender,age or tumor size of the patient(p>0.05).Conclusion:PEBP4 protein overexpression was associated with the occurrence,invasion and metastasis of lung squamous cell carcinoma.PEBP4 gene expression and its significance in invasionand metastasis of non-small cell lung cancerObjective:The goal of this study was to investigate the function of phosphatidylethanolamine-binding protein 4(PEBP4)in invasion and metastasis of non-small cell lung cancer,and the findings were expected to provide experimental bases for the future biological treatment of humuan non-small cell lung cancer.Methods:PEBP4 mRNA and protein expression in 56 cases of non-small cell lung cancer tissues were detected using RT-PCR and Western blot,and the relationship between PEBP4 expression and invasion and metastasis of non-small cell lung cancer was analyzed.The change in the invasive ability of human non-small small lung cancer cell line HCC827 was observed after PEBP4 expression was knocked down using RNA interference.Results:PEBP4 mRNA and protein expression in cancer tissues of patients with lymph node metastasis were significantly higher than in patients without lymph node metastasis(p<0.05).PEBP4 expression significantly decreased in HCC827 cells after transfection with PEBP4 siRNA(p<0.01),and the num ber of these cells that migrated through Transwell chambers was significantly lower than non-transfected control and transfected control cells(p<0.01).Conclusion:PEBP4 over-expression may promote the invasion and metastasis of non-small cell lung cancer.Down-regulation of PEBP4,a target of miR-34a,sensitizes drug-resistant lung cancer cellsThe aim of this study was to determine the relationship and underlying mechanisms between ectopic expression of phosphatidylethanolamine-binding protein 4(PEBP4)and cisplatin(DDP)isms between ectopic expression of phosphatidylethanolamine-binding protein 4(PEBP4)and cisplatin(DDP)-induced cytotoxicity in the lung cancer cell line A549 to provide an experimental basis for future chemotherapeutic applications involving PEBP4 in human lung cancer.Methods:A recombinant plasmid,pcDNA3-PEBP4,and a PEBP4-targeting shRNA were transfected into the lung cancer cell line A549.The PEBP4 protein expression levels were determined for each group by Western blot,and after 48 hours of cisplatin(DDP)treatment,the viability of cells in the treatment and control groups was determined by MTT assay.Apoptosis in each treatment group was determined using flow cytometry.Western blotting was used to examine expression of the p53 protein in A549 cells from each group.We employed a luciferase reporter-gene assay to confirm PEBP4 as a target gene of miR-34a.Western blotting was used to determine the effects of miR-34a on PEBP4 protein expression in A549 cells.Results:Following transfection of A549 cells with either the recombinant plasmid pcDNA3-PEBP4 or a PEBP4-targeting shRNA,Western blotting analyses showed PEBP4 protein expression was significantly higher in the pcDNA3-PEBP4-transfected group compared with the control or PEBP4-shRNA-transfected groups(p<0.01).Furthermore,PEBP4 protein expression was significantly reduced in the PEBP4-shRNA-transfected group(p<0.01).After 48 h of DDP treatment,MTT assays indicated that A549 cell viability was significantly lower in the DDP-treated group compared with the control group(p<0.01).The viability of A549 cells in the pcDNA3-PEBP4-transfected group was lower than that in the control group(p<0.05)but higher than that in either the DDP-treated or PEBP4-shRNA-transfected groups(p<0.05).Moreover,the viability of A549 cells in the PEBP4-shRNA-transfected group was significantly lower than that in either the control(p<0.01)or DDP-treated(p<0.05)groups.Flow cytometry and Western blotting analyses indicated that the number of apoptotic cells and p53 protein expression were significantly higher in the DDP-treated group compared with the control group(p<0.01).In the pcDNA3-PEBP4-transfected group,the number of apoptotic cells and p53 protein expression level were higher than those in the control group(p<0.05)but lower than those in the DDP-treated and PEBP4-shRNA-transfected groups(p<0.05).The number of apoptotic cells and p53 protein expression level in the PEBP4-shRNA-transfected group were higher than those in the control(p<0.01)and DDP-treated(p<0.05)groups.The luciferase reporter-gene assay showed that the relative luciferase activity after transfection with a miR-34a mimic was significantly reduced compared with the control group(p<0.01).Western blotting analysis demonstrated that PEBP4 protein expression was significantly decreased in A549 cells 48 h after transfection with a miR-34a mimic compared with the control group(p<0.01).Conclusion:Over-expression of PEBP4 reduced the sensitivity of A549 cells to DDP-induced cytotoxicity,mainly through the altered expression of the p53 protein or the modulation of miR-34a.