PRDX4 overexpression is associated with poor prognosis in gastric cancer

Validation of the interaction between PRDX4 and TXNDC5 in gastric cancer and the significance of the PRDX4 gene in gastric cancer based on a data mining analysis

Background

We successfully screened the important interacting protein peroxiredoxin 4 (PRDX4) of thioredoxin domain-containing protein 5 (TXNDC5) in gastric cancer. However, its specific molecular mechanism in gastric cancer remains unclear. This study aimed to verify the interaction between PRDX4 and TXNDC5 protein molecules in gastric cancer and analyze the expression and functional significance of PRDX4 in gastric cancer using bioinformatics methods.

Methods

The interaction between TXNDC5 and PRDX4 was verified by the coimmunoprecipitation (co-IP) of the total protein of gastric cancer cells, and tissues with high expressions of TXNDC5. The Human Protein Atlas (HPA) database, UCSC Xena (University of California Santa Cruz xenabrowser) platform, the Kaplan-Meier Plotter platform, and the TIMER (Tumor IMmune Estimation Resource) platform were used to analyze the expression and subcellular localization of the PRDX4 molecule in normal human gastric tissue, the difference in expression between gastric cancer tissue and normal gastric tissue, the relationship between the expression of PRDX4 and survival, its functional significance in gastric cancer cells, and its effect on the tumor immune microenvironment (TIME).

Results

The data analysis results showed that the expression of PRDX4 messenger RNA (mRNA) in the gastric cancer tissues was significantly higher than that in the normal tissues (P<0.05). PRDX4 could affect the occurrence and development of tumors by participating in the neutrophil degranulation signaling pathway to regulate tumor immunity. The expression level of PRDX4 has a certain relationship with the TIME; that is, it is mainly negatively correlated with the infiltration of B lymphocytes and CD4+ T lymphocytes (P<0.05). The expression level of PRDX4 was positively correlated with the expression of LILRB2 (leukocyte immunoglobulin-like receptor subfamily B member 2), and negatively correlated with BLTA (B and T lymphocyte attenuation factor) and VISTA (V-type immunoglobulin domain-containing suppressor of T cell activation) (P<0.05).

Conclusions

There is an interaction between PRDX4 and TXNDC5 protein molecules in gastric cancer. PRDX4 gene expression is significantly up-regulated in gastric cancer. It may reduce the infiltration of B lymphocytes and CD4+ T lymphocytes and affect the expression of LILRB2, BLTA, and VISTA immune checkpoints, leading to anti-tumor immunosuppression.

Exploring the role of PRDX4 in the development of uterine corpus endometrial carcinoma

Peroxicedoxin 4 (PRDX4), a member of the peroxicedoxins (PRDXs), has been reported in many cancer-related studies, but its role in uterine corpus endometrial carcinoma (UCEC) is not fully understood. In the present study, we found that PRDX4 was highly expressed in UCEC tissues and cell lines through the combination of bioinformatics analysis and experiments, and elevated PRDX4 levels were associated with poor prognosis. Knockdown of PRDX4 significantly blocked the proliferation and migration of the UCEC cell line Ishikawa and reduced degree of cell confluence. These findings highlight the oncogenic role of PRDX4 in UCEC. In addition, genes that interact with PRDX4 in UCEC were MT-ATP8, PBK, and PDIA6, and we speculated that these genes interacted with each other to promote disease progression in UCEC. Thus, PRDX4 is a potential diagnostic biomarker for UCEC, and targeting PRDX4 may be a potential therapeutic strategy for patients with UCEC.

The combination of the low immunohistochemical expression of peroxiredoxin 4 and perilipin 2 predicts longer survival in pancreatic ductal adenocarcinoma with peroxiredoxin 4 possibly playing a main role

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease with poor prognosis. Therefore, indicators that can be used for the early prediction of the prognosis of PDAC are needed. Peroxiredoxin (PRDX) 4 is a secretion-type antioxidant enzyme located in the cytoplasmic endoplasmic reticulum. Recent studies have reported that it is closely related to the development and prognosis of many types of cancer. Perilipin (PLIN) 2 is a lipid droplet coating protein. The high expression of PLIN2 is known to be an indicator of some types of cancer and oxidative stress management. It is highly suggestive of the interplay between PRDX4 and PLIN2 to some degree. In this study, we collected 101 patients' clinical data and paraffin-embedded specimens with PDAC and analyzed them with immunohistochemical staining of PRDX4 and PLIN2. We found that the low expression of PRDX4 predicts longer survival and a better clinical condition in PDAC patients. Moreover, when the low expression of PRDX4 is combined with the low expression of PLIN2, the 3-year survival is significantly improved. Univariate and multivariate Cox proportional hazard analyses showed that the PRDX4 expression in PDAC was an independent prognostic factor for survival. Taken together, between PRDX4 and PLIN2, PRDX4 plays a main role in prognosis and has the potential to become a clinical prognostic indicator of PDAC.

Essential Roles of Peroxiredoxin IV in Inflammation and Cancer

Peroxiredoxin IV (Prx4) is a 2-Cysteine peroxidase with ubiquitous expression in human tissues. Prx4 scavenges hydrogen peroxide and participates in oxidative protein folding in the endoplasmic reticulum. In addition, Prx4 is secreted outside the cell. Prx4 is upregulated in several cancers and is a potential therapeutic target. We have summarized historical and recent advances in the structure, function and biological roles of Prx4, focusing on inflammatory diseases and cancer. Oxidative stress is known to activate pro-inflammatory pathways. Chronic inflammation is a risk factor for cancer development. Hence, redox enzymes such as Prx4 are important players in the crosstalk between inflammation and cancer. Understanding molecular mechanisms of regulation of Prx4 expression and associated signaling pathways in normal physiological and disease conditions should reveal new therapeutic strategies. Thus, although Prx4 is a promising therapeutic target for inflammatory diseases and cancer, further research needs to be conducted to bridge the gap to clinical application.