Gene Profiling And The Expression Of P53 And KRAS In Lung Adenocarcinoma And Their Significance

Background Lung cancer is one of the cancers with the highest incidence and mortality.The occurrence of lung cancer is related to many factors.Lung adenocarcinoma is the most common diagnosis of lung cancer.Studies have found that the occurrence and development of lung adenocarcinoma is closely related to the genetic diversity and susceptibility to genetic changes.Therefore,studying the mutational gene profile of lung adenocarcinoma is of great significance for the clinical diagnosis and treatment of lung adenocarcinoma.Aim To detect and analyze the gene profile of lung adenocarcinoma,to identify the types and distribution of common gene mutations in lung adenocarcinoma,and the expression and significance of common gene mutations in lung adenocarcinoma.To compare the reliability of IHC and ARMS-PCR methods for detecting lung adenocarcinoma gene mutations,using the second-generation sequencing results as the gold standard.Methods 1)Using next-generation sequencing technology to detect 26 common tumor-related hot genes in 29 paraffin samples of lung adenocarcinoma;analyze the relationship between high mutation rate gene expression and clinicopathological characteristics of lung adenocarcinoma;analyze the correlation of gene co-expression. 2)Randomly selected 18 cases of lung adenocarcinoma samples in 29 paraffin samples using IHC to detect EGFR mutations and compare them with second-generation sequencing results;the remaining 11 cases used ARMS-PCR method to detect EGFR mutations and compared with second-generation sequencing results.3)IHC was used to detect TP53 and KRAS mutations in 29 lung adenocarcinoma samples,and compared with the results of next-generation sequencing 4)Expand the samples of 29 cases of lung adenocarcinoma to 99 cases,use IHC to detect the expression of p53 protein and KRAS protein,analyze the relationship between the expression of both and the clinicopathological characteristics of lung adenocarcinoma,and analyze the expression of p53 and KRAS in lung adenocarcinoma tissue correlation.Results 1)Six genes were found to be mutated in 26 genes tested,namely EGFR(21/29),p53(12/29),KRAS(3/29),ROS1(3/29),ALK(1/29))And RET(1/29).2)EGFR mutations mostly occurred in exons 19(9/21)and 21(10/21),and 2 occurred in exon 20(1 of which was on exons 20 and 21)(Both mutations),one case occurred in exon 18.p53 mutations are located on the 6(4/12),4(2/12),5(2/12)and 8(2/12),7(1/12)and 10(1/12)Exons;KRAS mutations occurred in exon 2(3/3).3)In the 29 cases,14 had co-mutations,of which 1 case had co-mutations of 3 genes(EGFR,KRAS,ROS1).And 13 cases had double-gene mutations(10 cases of EGFR and p53,1 case of EGFR and KRAS,and 1 case of EGFR and ROS1,1 case of p53 and KRAS).12 cases had a single gene mutation,and 3 cases detected no genetic mutation.4)In 29 lung adenocarcinoma samples,the four genes,EGFR,TP53,KRAS,and ROS1,did not show any correlation with the clinicopathological characteristics(including age,gender,tumor diameter,lymph node metastasis,and pathological subtypes).And the expression of any two genes in lung adenocarcinoma tissues showed no correlation.This may due to the small sample size.5)In the detection of EGFR mutations,the ARMS-PCR method showed good agreement with the next-generation sequencing,while the IHC method showed false positive and false negative results,which was less consistent with the second-generation sequencing.6)In the detection of TP53 and KRAS mutations,IHC and second-generation sequencing results are in good agreement.7)The results of immunohistochemical detection of 99 lung adenocarcinoma tissue samples showed that the positive rate of p53 in lung adenocarcinoma tissue was 30.3%,and the positive rate of KRAS was 23.2%.There was no significant correlation between the two expressions(r = 0.054,P = 0.594).8)In 99 lung adenocarcinoma tissue samples,p53 expression was not related to patient gender,age,pathological subtype,tumor size,presence or absence of lymph node metastasis,TNM staging,and degree of differentiation(P> 0.05),and KRAS expression was also related to patient age.,Pathological subtype,tumor size,presence or absence of lymph node metastasis,TNM stage and differentiation were not related(P> 0.05),but KRAS expression was higher in male(36.4%)lung adenocarcinoma than in female(12.7%)(P <0.05).Conclusion There are multiple gene mutations in lung adenocarcinoma tissues,and co-mutations can be found.EGFR mutations are mostly in exons 19 and 21,p53 mutations are mostly concentrated in exons 6,4,5,and 8 and KRAS mutations.Mostly in exon 2,and KRAS mutations are more common in male patients.IHC is less reliable than ARMS-PCR and next-generation sequencing in detecting EGFR mutations.