Detection Of Gene Mutation In Cervical Cancer Using High-throughput Sequencing

Objective: To detect genes mutations in cervical cancer patients using the high-throughput sequencing technology,understand its gene mutation spectrum,and analyze the relationship between common gene mutations and relevant clinicalpathological factors of cervical cancer,in order to lay a foundation for finding the key gene mutations of cervical cancer and potential therapeutic targets for cervical cancer.Methods: Clinical data,FFPE tissue samples,plasma samples and blood leukocyte samples(tissue and plasma samples served as experimental group and blood leukocyte samples served as control group)of cervical cancer patients hospitalized in Department of Gynaecology Oncology,Affiliated Tumor Hospital of Guangxi Medical University from December 2016 to January 2018 were collected.All samples were subjected to genomic DNA extraction,then Hiseq4000 sequencing platform was used for high-throughput sequencing of gene detection,which including sequencing library construction,the use of 422 panel probe targeted enrichment of target gene fragments,sequencing,bioinformatics analysis,etc.Ultimately obtained gene mutations of all patients and conducted a summary analysis.Results: 1.Of the 28 patients with cervical cancer,92.9%(26/28)of the patients had detected mutations,and a total of 99 mutations were identified.The top 10 gene mutations were: PIK3CA(46.2%),RB1(15.4%),AKT2(11.5%),FAT1(11.5%),KMT2B(11.5%),MCL1(11.5%),MYCN(11.5)%),PKHD1(11.5%),RPTOR(11.5%)and STK11(11.5%).The mutated genes matched with those resported in the literature were: PIK3CA(46.2%),RB1(15.4%),AKT2(11.5%),STK11(11.5%),ATM(7.7%),ERBB2(7.7%),KARS(7.7%),and PTEN(7.7%).Single or multiple mutations in these genes caused cervical cancer patients to differ in tumor size,differentiation,vascular tumor emboli,and lymph node metastasis(P< 0.05).2.The types of gene mutations in cervical cancer patients include missense mutations,nonsense mutations,frameshift mutations,indels,and copy number variations,among which missense mutations and copy number variations are the most common.3.Signaling pathways involved in gene mutation in cervical cancer patients include: PI3K-AKT signaling pathway,FoxO signaling pathway and Ras signaling pathway.4.The most common mutated gene PIK3 CA in this study is located on chromosome 3,and its exon mutation sites are: Exon9(75.00%),Exon8(8.33%),Exon19(8.33%),and Exon20(8.33%).In these patients’ PIK3 CA genotypes,the proportions were ranked as follows: E452K(33.33%),E545K(25.00%),E453K(8.33%),R899H(8.33%),and H1047R(8.33%),and the mutation type All missense mutations(100%).There was a correlation between PIK3 CA gene mutations and histopathological grade(degree of differentiation)in patients,but age,ethnicity,tumor size,clinical stage,histological type,lymph node metastasis,and presence or absence of high-risk HPV.There was no significant difference in infection(P>0.05).The PI3K-AKT signaling pathway involved in the PIK3 CA gene has abnormalities(mutations in PIK3 CA or AKT2)that are associated with histological type,differentiation,vascular tumor embolus,and lymph node metastasis(P<0.05).Conclusions: Gene mutations are common in cervical cancer,and are mainly multi-genes mutations.PIK3 CA is the most common mutated gene in cervical cancer patients.As one of the most potential pathways,PI3K-AKT signaling pathway plays an important role in the carcinogenic process of cervical cancer.The abnormality of PIK3 CA mutation and PI3K-AKT signaling pathway is closely related to the degree of tumor differentiation,vascular tumor thrombosis,and lymph node metastasis in patients with cervical cancer.The relationship between PIK3 CA mutation and PI3K-AKT signaling is worthy of further study and may be a drug treatment target for cervical cancer.In addition,we discovered some new mutations,which extended the gene mutation spectrum of cervical cancer.