A Study Of A New Gene Therapy To Non-small Cell Lung Cancer

Lung cancer is the leading cause of cancer-related death worldwide.Non-small cell lung cancer(NSCLC)accounts for 85%of all lung cancers.Most patients have advanced disease at diagnosis and palliative therapy is the mainly treatment.The median survival of patients with untreated metastatic non-small-cell lung cancer is only four to five months,with a survival rate at one year of only 10 percent.The effect of conventional chemotherapy of NSCLC has apparently reached a plateau,so it is very important to develop a new method to treat lung cancer patients.The expressed level of eIF4E is related to the pathological grade the clinical stage,prognosis and the survival rate of Non-small cell lung cancer,and the eIF4F complex is activated by PI3K/Akt/mTOR/4EBP1 cell signal channel or RAS/RAF/MEK/ERK/Mnkl/eIF4E cell signal channel,which triggered by the mutation in lung cancer.Futhermore the eIF4F complex adjusted the expressed level of many proteins which is related to the growth of tumor,the resistance of chemotherapy and the angiogenesis of tumor.As a result we suggested that the eIF4F complex may be used as a new target for the gene therapy of Non-small cell lung cancer(NSCLC).mTOR by identifying structural motifs IP TOS motif structure and carboxy-terminal amino 4EBP1 protein amino terminus and the completion of a particular substrate phosphorylation of 4EBP1.This study constructs a eukaryotic expression vector pSec-4EBP1 of truncated 4EBP1 mutant by removing RAIP motif and TOS motif of 4EBP1.On one hand,a phosphorylation-deficient 4EBP1 can block the assembly of eIF4F complex;and on the other hand,an antisense RNA of eIF4E can inhibit the expression of eIF4E.We construct an eIF4E-specific RNA interfering vector pSingle-eIF4E,suppressing the expression of eIF4E by eIF4E antisense RNA and thus reducing the formation of eIF4F complex.Through the above two mechanisms,the assembly of eIF4F complex in lung cancer A549 cell can be reduced,thereby suppressing the growth of tumor.This study demonstrates that,in comparison with the antisense RNA of eIF4E,the phosphorylation-deficient 4EBP1 can better suppress the eIF4F complex.The targeted inhibition on assembly of eIF4F complex can inhibit the proliferation of lung cancer A459 cell,promote the apoptosis,and inhibit the invasiveness and migration ability thereof.The phosphorylation-deficient 4EBP1 can downregulate the expression of molecules which are closely related to the occurrence and development of non-small cell lung cancer downstream the eIF4F complex.The transfection of pSec-4EBP1 can induce the tumor regression in a human lung adenocarcinoma-burdened animal model.These molecular and animal experimental results indicate that the truncated and phosphorylation-deficient 4EBP1 gene therapy can play a role in the suppression of non-small cell lung cancer,and thus can be regarded as a gene therapy scheme of non-small cell lung cancer.