Abstract
The peroxiredoxin (PRDX) family, also known as the peroxidase family, consists of six members that participate in a variety of essential bio-processes in carcinogenesis. However, their molecular role in lung adenocarcinoma (LUAD) has not been systematically explored. Using bioinformatic tools, we systematically analyzed the expression, prognostic value and drug sensitivity of the PRDX gene family members in LUAD. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to verify the expression of PRDX1 in both LUAD tissues and cells. Cell Counting Kit-8 (CCK-8) assay was applied to detect the half-maximal inhibitory concentration (IC(50)) of osimertinib in LUAD. A series of cellular drug assays, including 5-Ethynyl-2'-deoxyuridine (EdU), colony formation, and apoptosis assays, were performed to explore the correlation of PRDX1 with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) sensitivity by using EGFR-mutant and wild-type LUAD cell lines. Among all the PRDX family members, PRDX1 has a promising prognostic value and is associated with EGFR mutations, as verified by experiments conducted on collected LUAD specimens. In addition, pathway enrichment analysis suggested that PRDX1 expression positively correlated with DNA repair, which is often considered to be inextricably linked to drug resistance in tumor cells. Thus, we validated the correlation between PRDX1 and EGFR-TKI sensitivity through a series of in vitro experiments and found that PRDX1 inhibition along with osimertinib treatment resulted in synergistic inhibition of tumor growth. Moreover, we found that PRDX1 was negatively correlated with the immune infiltration of dendritic cells (DCs) in the tumor microenvironment (TME) of LUAD, further suggesting an oncogenic role of PRDX1. This study demonstrates that high PRDX1 expression could be a potential diagnostic and prognostic marker of LUAD, and the strategy of PRDX1 knockdown provides new insights into improving the therapeutic sensitivity of EGFR-TKI in patients with LUAD.