Relationship Between PGK1 Expression And Chemotherapy Efficacy And Prognosis Of Lung Adenocarcinoma Patients

Objective: The incidence of lung cancer ranks first among malignant tumors in China,lung adenocarcinoma being its main pathological type.Tyrosine kinase inhibitor(TKIs)is effective for patients with EGFR mutation with the development of medicine.but most patients with EGFR mutation will develop a certain degree of drug resistance to TKIs in the later stage of treatment.Related research shows that chemotherapy can prolong the Overall survival(OS)of patients after drug resistance.Therefore,chemotherapy is an indispensable means for both lung adenocarcinoma patients.Unfortunately,many patients with lung adenocarcinoma will develop drug resistance after chemotherapy,which seriously affects the efficacy of chemotherapy and the prognosis of patients.Therefore,the reduction of chemotherapy sensitivity has become a major obstacle in the clinical treatment of lung adenocarcinoma.The purpose of this dissertation is to explore the key genes and related mechanisms affecting chemotherapy sensitivity in lung adenocarcinoma patients,and further study their effects on the prognosis of lung adenocarcinoma patients and establish a prognostic model to predict the survival time of lung adenocarcinoma patients.Methods:(1)The gene expression data of A549 cell line after chemotherapy was downloaded from GEO database,and the differential gene analysis was carried out by MCC,MNC and Bottle Neck to screen out the key gene.(2)The mechanism of PGK1 affecting chemotherapy sensitivity in lung adenocarcinoma patients was explored through q RT-PCR,cell proliferation inhibition assay(MTS method)and Western blot.(3)Thirty-nine lung adenocarcinoma patients undergoing chemotherapy were selected from the GEO database to analyse the relationship between PGK1 and chemotherapy efficacy by plotting K-M curves.(4)Data from lung adenocarcinoma patients were collected from the TCGA database,and after matching clinical information,samples from 450 patients were included.Firstly,according to whether the patient’s EFGR was mutated,the samples of these 450 patients were divided into two parts of the EGFR mutant and wild type for PGK1 expression analysis.Secondly,the independent influencing factors of OS were screened out by univariate COX regression analysis and multivariate COX regression analysis.And according to the median value,PGK1 here was divided into high-expression and low-expression groups for K-M curves to analyse its relationship with the clinicopathological characteristics of lung adenocarcinoma patients.Subsequently,R was used to observe the differences in the expression of key factors in different stages.Finally,a prognostic model was established combining PGK1 expression and tumor stage,to predict the survival time of lung adenocarcinoma patients.P<0.05 here is statistically significant.Results:(1)PGK1 is associated with chemotherapy sensitivity in patients with lung adenocarcinoma.Three methods of MCC,MNC and Bottle Neck have been used in this dissertation to analyse the differential genes in the two data sets of GSE144520 and GSE108214,and finally screened out the high expression of PGK1 gene in lung adenocarcinoma resistance cells for follow-up research.(2)PGK1 may alter the sensitivity of LUAD patients to chemotherapy through the AKT/m TOR pathway.(a)The MTS test demonstrated that the survival rate of A549 cells and PC9 cells decreased,and chemotherapy sensitivity increased after silencing PGK1.(b)According to the expression of PGK1,PGK1 was divided into high expression group and low expression group,and KEGG pathway enrichment analysis was performed.The results showed that high PGK1 expression may be significantly related to the activation of the AKT/m TOR pathway.(c)Therefore,we observed that the expression levels of p-AKT and p-m TOR proteins decreased significantly after silencing PGK1 through the Western-blot experiment.(3)High expression of PGK1 may lead to decreased efficacy of chemotherapy in patients with lung adenocarcinoma.The GSE42127 cohort was selected in the GEO database for clinical validation,and 39 patients with lung adenocarcinoma treated with carboplatin combined with paclitaxel were screened out for analysis.We found that there was a high expression trend of PGK1 in the tissues of deceased patients after treatment(P = 0.051),and PGK1 expression was high in the group of deceased patients(P=0.0286)after adjusting for age,sex,race,and other factors.In addition,we also concluded that the survival time of the PGK1 high expression group was shorter among all patients receiving chemotherapy through the survival curve(P=0.087).(4)High expression of PGK1 is associated with poor prognosis in patients with lung adenocarcinoma.(a)We divided the 450 patients collected in the TCGA database into EGFR mutant and wild-type and found no significant difference in the expression of PGK1(P=0.18).(b)Univariate and multivariate COX regression analyses were performed,and the results showed that PGK1,depth of tumor invasion and lymph node metastasis were independent factors influencing OS in lung adenocarcinoma patients.(c)The difference in prognosis between the two groups with high and low expression of PGK1 was analysed by K-M survival curve,and female(P=0.028),age ≥65(P=0.003),other races other than Caucasian(P=0.005),T2(P=0.049),and M0(P=0.05)were associated with poor prognosis in high PGK1 expression.(d)The expression of PGK1 can be positively correlated with tumor T stage(P=0.037),N stage(P=0.026)and disease stage(P=0.0095)by using R.(5)A prognostic model for patients with lung adenocarcinoma was established by combining PGK1 expression with tumor stage.According to the above results,a nomogram of PGK1 and tumor stage was established.These results showed that the sensitivity and specificity of this prognostic model were higher than other clinical factors,and it was close to the survival time of lung adenocarcinoma patients in the real world.Conclusion: In this dissertation,PGK1 may reduce the chemosensitivity of lung adenocarcinoma by activating AKT/m TOR pathway,and the high expression of PGK1 leads to poor chemotherapy efficacy and poor prognosis in lung adenocarcinoma patients.The survival time of lung adenocarcinoma patients could be predicted by establishing a prognostic model based on PGK1 expression and tumor staging.