A pan-cancer analysis of the oncogenic and anti-tumor immunity role of P4HA3 in human cancers

Background Prolyl-4-hydroxylase subunit alpha3 (P4HA3) is a triple helical procollagen synthesis protein. The role of P4HA3 in cancer development is not well known and lacks comprehensive analyses among human cancers. This study aimed to investigate the relationship between P4HA3 expression and anti-tumor immunity and its prognostic value in pan-cancer. Methods P4HA3 expression in pan-cancer patients were analyzed from TIMER2.0, Genotype Tissue Expression (GTEx), GEPIA2.0 and TCGA databases. Genetic and DNA methylation alterations, survival analysis and proteins co-expression analysis of P4HA3 in pan-cancer among numerous databases, including cBio Cancer Genomics Portal, TCGA, GSCA and TIMER2.0. The correlation between P4HA3 expression and immune infiltration was analyzed TIDE, XCELL, MCPCOUNTER, and EPIC. Gene function enrichment analysis was carried out by Gene Set Enrichment Analysis (GSEA). We performed EdU and transwell experiments to evaluate the influence of P4HA3 on the proliferation, migration and invasion abilities of 3 kinds of tumors in vitro . Patients derived xenograft (PDX) and subcutaneous transplantation models were utilized to explore the correlation between P4HA3 and immunotherapy response in triple-negative breast cancer (TNBC). Results Among 33 types of cancers, P4HA3 had generally different expression between tumor and tumor tissues, the abnormal expression of P4HA3 was associated with DNA methylation alteration and survival regimen of tumor patients. Further analysis showed that the expression of P4HA3 was correlated with the cells infiltration of the tumor microenvironment (TME), including immune cells, cancer-associated fibroblasts (CAFs), and stroma cells. Meanwhile, the expression of P4HA3 was positively with the cell proliferation markers and epithelial-mesenchymal transition (EMT) markers, that suggesting P4HA3 is involved in cancer proliferation and metastasis. Moreover, the molecular biology experiments in vitro and in vivo showed that P4HA3 deficiency inhibited the proliferation, migration and invasion abilities of tumor cells, and promoted anti-tumor immunotherapy of PD-1/PD-L1 inhibitor. Conclusion This pan-cancer analysis of P4HA3 provides a comprehensive understanding of its oncogenic and prognosis role in different cancers, P4HA3 abnormal expression could be a useful biomarker for predicting the effectiveness of immunotherapy in cancer patients.