Expression And Clinical Implications Of Glycosylphosphatidylinositol Transaminase (GPI-T) Complex-Related Genes In The Ovarian Cancer Tissues

Background:Ovarian cancer(OC)has become one of the seventh most common cancers among women worldwide and the eighth most common cause of cancer death.At present,there are lack of effective tumor screening markers and diagnostic methods for early tumor screening of ovarian cancer.It is reported that about 70% of ovarian cancer patients are already in advanced stage at the time of diagnosis,and only about one-third of patients can survive five years after diagnosis.Although the level of medicine has improved in recent years,But based on the latest statistics released by the National Cancer Center(NCC),the five-year survival rate for ovarian cancer in this country has only improved by about 0.4 percent,which shows that the improvement is not significant.In recent years,with the rapid development of high-throughput sequencing technology and transcriptome research,The number of key driver genes is increasing.Previous studies have shown that the GPI-T(glycophosphatidylinositol aminotransferase)complex plays a key role in cancer development.Phosphatidylinositoglycan U(PIGU)is the main subunit of this complex,and the significantly high expression of PIGU is closely associated with poor survival in patients with various tumors,but its relationship with ovarian cancer has not been reported.In this study,the correlation between GPI-T complex related genes and ovarian cancer patients was analyzed for the first time by combining bioinformatics and in vitro experiments,in order to find new biomarkers for ovarian cancer prediction.Objective:To investigate the expression and clinical significance of the key gene PIGU of glycosyl phosphatidylinositol aminotransferase(GPI-T)complex in ovarian cancer.Methods:1.Based on TCGA and GETx databases,the expression levels of glycosyl phosphatidylinositol aminotransferase(GPI-T)complex related genes,including PIGU,PIGT,GPAA1,PIGS and PIGK,in ovarian cancer tissues and adjacent tissues were analyzed.2.Based on Kaplan-Meier plotter database,the total survival time and progression-free survival time of glycosyl phosphatidylinositol aminotransferase(GPI-T)complex related genes,including PIGU,PIGT,GPAA1,PIGS and PIGK in ovarian cancer patients were analyzed to evaluate the prognostic impact;3.Based on GEO database,data sets with adjacent control tissues(GSE18520and GSE26712)were selected to verify that the expression level of target genes was highly expressed in ovarian cancer tissues4.Based on WB method,the expression of target genes in ovarian cancer tissues and adjacent tissues of clinical patients was detected.5.Based on CCK8 method,the effect of silencing target gene on proliferation of A2780 and OVCAR3 ovarian cancer cells was detected.6.Based on the median PIGU expression level in TCGA database,ovarian cancer patients were divided into high and low expression groups for difference analysis,and the results were analyzed in WEBGESTALT online pathway analysis page.7.Based on q RT-PCR experiments,the overexpression of target genes and knockdown of target genes in A2780 and OVCAR3 ovarian cancer cell lines were examined for their effects on related pathway genes in cell cycle pathways.Results:1.Compared with TCGA and GTEx data,Compared with normal tissues,PIGS were significantly reduced in OC tissues.The expression of PIGK,PIGU,PIGT,and GPAA1 was significantly up-regulated in ovarian cancer tissues,with P values below0.05,indicating significant differences.2.In GEO database,the expression level of PIGU was significantly higher in ovarian cancer patients,with statistical significance.3.According to the analysis of overall survival time and progression-free survival time,it was found that only PIGU had adverse outcomes for overall survival and progression-free survival.The differences were statistically significant(P<0.05)4.WB test results showed that PIGU was significantly expressed in ovarian cancer tissues compared with adjacent control tissues.5.CCK8 results showed that the proliferation ability of ovarian cancer cell lines was significantly reduced after PIGU knockdown.6.WEBGESTALT online pathway analysis results suggested that PIGU is closely associated with ovarian cancer cell cycle pathway.7.QRT-PCR experimental results showed that the expression of CDK2,CDK7,E2F1,PLK1 and BUB3 genes under the cell cycle pathway was positively correlated with the expression of PIGU gene,while the expression of TP53 gene was negatively correlated with the expression of PIGU gene,indicating that the expression of PIGU gene affected the cell cycle pathway.Conclusion:1.PIGU is significantly overexpressed in ovarian cancer,which is closely associated with poor prognosis of ovarian cancer patients.2.High expression of PIGU can affect cell cycle pathway and thus affect the occurrence and development of ovarian cancer,which may be one of the potential markers to predict the occurrence,development and prognosis of ovarian cancer.