Objectives To explore the potential diagnostic and prognostic biomarkers associated with prostate cancer (PCa).
Methods We downloaded from the Gene Expression Omnibus (GEO) database, six previously published datasets containing gene expression data (GSE8511, GSE14206, GSE46602, GSE55945, GSE69223, and GSE71016). Take GSE8511, GSE14206, GSE46602, and GSE55945 as the training group (127 PCa cases and 52 normal controls) and GSE69223 and GSE71016 as the test group (63 PCa cases and 62 normal controls). Between 127 PCa cases and 52 normal controls, differentially expressed genes (DEGs) were filtered. Following that, candidate PCa biomarkers were discovered using a least absolute shrinkage and selector operation (LASSO) regression model and support vector machine recursive feature elimination (SVM-RFE) analyses. We conducted a difference analysis for these genes in the test group, and a significance level of P< 0.05 was considered statistically significant. To determine the train group’s discriminating ability, the area under the receiver operating characteristic curve (AUC) value was acquired and utilized, with hub genes defined as those having an AUC greater than 85%. The biomarkers’ expression levels and diagnostic utility in PCa were confirmed further in the GSE69223 and GSE71016 datasets. Lastly, to assess the relevant invasion of cells per every sample, the CIBERSORT algorithm and the ESTIMATE technique were utilized.
Results The possible PCa diagnostic biomarkers AOX1, APOC1, ARMCX1, FLRT3, GSTM2, and HPN were found and verified using the GSE69223 and GSE71016 datasets. Immune cell infiltration analysis revealed that AOX1, APOC1, ARMCX1, FLRT3, GSTM2, and HPN were correlated with Mast cells resting, Macrophages M0, Macrophages M2, Neutrophils, NK cells activated, T cells CD4 memory resting, T cells gamma delta, T cells follicular helper, T cells CD4 naive and B cells memory. Meanwhile, AOX1 was identified as an oxidative stress-related biomarker that could use to be a prognostic biomarker. From expreimental validations, we detected that AOX1 was lowly expressed in PCa cell lines. Overexpression of AOX1 clearly reduced the proliferation and migration of the PCa cells, the anti-tumor effect of APX1 may be related to oxidative stress.
Conclusion We used a multi-pronged approach to identify PCa biomarkers and examine the important function of infiltration of cells in PCa. AOX1, APOC1, ARMCX1, FLRT3, GSTM2, and HPN can be used as diagnostic markers of PCa, and AOX1 can be used to predicting the prognosis, which providing new perspectives into the incidence and molecular mechanisms of PCa in the future.