Peroxiredoxin 2 is highly expressed in human oral squamous cell carcinoma cells and is upregulated by human papillomavirus oncoproteins and arecoline, promoting proliferation

A Critical Interpretive Synthesis of the Role of Arecoline in Oral Carcinogenesis: Is the Local Cholinergic Axis a Missing Link in Disease Pathophysiology?

Arecoline is the primary active carcinogen found in areca nut and has been implicated in the pathogenesis of oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSF). For this study, we conducted a stepwise review process by combining iterative scoping reviews with a post hoc search, with the aim of identifying the specific mechanisms by which arecoline initiates and promotes oral carcinogenesis. Our initial search allowed us to define the current trends and patterns in the pathophysiology of arecoline-induced OSF and OSCC, which include the induction of cell proliferation, facilitation of invasion, adhesion, and migration, increased collagen deposition and fibrosis, imbalance in immune and inflammatory mechanisms, and genotoxicity. Key molecular pathways comprise the activation of NOTCH1, MYC, PRDX2, WNT, CYR61, EGFR/Pl3K, DDR1 signaling, and cytokine upregulation. Despite providing a comprehensive overview of potential pathogenic mechanisms of OSF, the involvement of molecules functioning as areca alkaloid receptors, namely, the muscarinic and nicotinic acetylcholine receptors (AChRs), was not elucidated with this approach. Accordingly, our search strategy was refined to reflect these evidence gaps. The results of the second round of reviews with the post hoc search highlighted that arecoline binds preferentially to muscarinic AChRs, which have been implicated in cancer. Consistently, AChRs activate the signaling pathways that partially overlap with those described in the context of arecoline-induced carcinogenesis. In summary, we used a theory-driven interpretive review methodology to inform, extend, and supplement the conventional systematic literature assessment workflow. On the one hand, the results of this critical interpretive synthesis highlighted the prevailing trends and enabled the consolidation of data pertaining to the molecular mechanisms involved in arecoline-induced carcinogenesis, and, on the other, brought up knowledge gaps related to the role of the local cholinergic axis in oral carcinogenesis, thus suggesting areas for further investigation.

Systematic review of comparative transcriptomic studies of cellular resistance to genotoxic stress

The development of resistance by tumor cells to various types of therapy is a significant problem that decreases the effectiveness of oncology treatments. For more than two decades, comparative transcriptomic studies of tumor cells with different sensitivities to ionizing radiation and chemotherapeutic agents have been conducted in order to identify the causes and mechanisms underlying this phenomenon. However, the results of such studies have little in common and often contradict each other. We have assumed that a systematic analysis of a large number of such studies will provide new knowledge about the mechanisms of development of therapeutic resistance in tumor cells. Our comparison of 123 differentially expressed gene (DEG) lists published in 98 papers suggests a very low degree of consistency between the study results. Grouping the data by type of genotoxic agent and tumor type did not increase the similarity. The most frequently overexpressed genes were found to be those encoding the transport protein ABCB1 and the antiviral defense protein IFITM1. We put forward a hypothesis that the role played by the overexpression of the latter in the development of resistance may be associated not only with the stimulation of proliferation, but also with the limitation of exosomal communication and, as a result, with a decrease in the bystander effect. Among down regulated DEGs, BNIP3 was observed most frequently. The expression of BNIP3, together with BNIP3L, is often suppressed in cells resistant to non-platinum genotoxic chemotherapeutic agents, whereas it is increased in cells resistant to ionizing radiation. These observations are likely to be mediated by the binary effects of these gene products on survival, and regulation of apoptosis and autophagy. The combined data also show that even such obvious mechanisms as inhibition of apoptosis and increase of proliferation are not universal but show multidirectional changes.

New insights into the roles of peroxiredoxins in cancer

Oxidative stress is one of the hallmarks of cancer. Tumorigenesis and progression are accompanied by elevated reactive oxygen species (ROS) levels and adaptive elevation of antioxidant expression levels. Peroxiredoxins (PRDXs) are among the most important antioxidants and are widely distributed in a variety of cancers. PRDXs are involved in the regulation of a variety of tumor cell phenotypes, such as invasion, migration, epithelial-mesenchymal transition (EMT) and stemness. PRDXs are also associated with tumor cell resistance to cell death, such as apoptosis and ferroptosis. In addition, PRDXs are involved in the transduction of hypoxic signals in the TME and in the regulation of the function of other cellular components of the TME, such as cancer-associated fibroblasts (CAFs), natural killer (NK) cells and macrophages. This implies that PRDXs are promising targets for cancer treatment. Of course, further studies are needed to realize the clinical application of targeting PRDXs. In this review, we highlight the role of PRDXs in cancer, summarizing the basic features of PRDXs, their association with tumorigenesis, their expression and function in cancer, and their relationship with cancer therapeutic resistance.

Expression and prognostic value of PRDX family in colon adenocarcinoma by integrating comprehensive analysis and in vitro and in vivo validation

Background

The peroxiredoxin family, a crucial regulator of redox reactions, is strongly associated with various tumorigenesis. However, the role of peroxiredoxin4 (PRDX4) in colon adenocarcinoma (COAD) remains poorly understood.

Methods

Multicenter databases, including GEPIA, HPA, UALCAN, cBioPortal, cancerSEA, STRING, CCLE, and LinkedOmics, comprehensively analyzed transcriptional expression, prognostic value, genetic alterations, signaling pathways, and associated genes of the PRDXs in COAD patients. Colony formation, transwell, flow cytometry, sphere formation, and xenograft assays were performed to validate further in vitro and in vivo.

Results

Members of the PRDX family were differentially expressed in COAD, with each member showing varying degrees of genetic alterations. Intriguingly, only PRDX4 significantly correlated with COAD prognosis and stage. The single-cell sequencing suggested that PRDX4 is positively correlated with proliferation, apoptosis, and invasion, whereas negatively correlated with stemness. Moreover, PRDX4 involved in a series of critical biological processes, such as cell growth. Furthermore, in vivo and in vitro analyses indicated that knocking down PRDX4 inhibits the proliferation and invasion of HCT116 cells while promoting apoptosis and stemness.

Conclusions

We identified PRDX4 expression as a novel potential prognostic marker in COAD.

Peroxiredoxin2 regulates trophoblast proliferation and migration through SPIB-HDAC2 pathway

Adequate proliferation and migration of placental trophoblasts is the prerequisite of a successful pregnancy. Peroxiredoxin2 (Prdx2) is a multi-functional gene involved in various signal events to maintain essential biological functions and normal cellular homeostasis. In this study, substantially lower Prdx2 levels were found in the first trimester cytotrophoblasts of women who suffered from recurrent miscarriage (RM). Prdx2 downregulation inhibited trophoblast proliferation and migration. We demonstrated that histone deacetylase2 (HDAC2) acts downstream of Prdx2 in regulating trophoblast proliferation and migration. HDAC2 deacetylates histone-3-lysine-9 in E-cadherin (E-cad) promoter and reduces the transcription of E-cad epigenetically, whereas it promotes the expression of Slug and Snail genes. These molecular changes may contribute to the trophoblast epithelial-mesenchymal transition. We further verified whether Prdx2 modulated the expression of HDAC2 through SPIB. SPIB could bind to the HDAC2 promoter PU-box region and induce HDAC2 expression. In RM, down-regulated Prdx2 suppresses SPIB-HDAC2 pathway, leading to increased E-cad and decreased Slug and Snail, and eventually restrains trophoblast proliferation and migration. Our study unveils the role of Prdx2-regulated SPIB-HDAC2 pathway in the pathology of RM and provides diagnostic and therapeutic targets for RM as well as other "great obstetrical syndromes" including preeclampsia and intrauterine growth restriction.

Development and validation of machine learning-based risk prediction models of oral squamous cell carcinoma using salivary autoantibody biomarkers

INTRODUCTION

The incidence of oral cavity squamous cell carcinoma (OSCC) continues to rise. OSCC is associated with a low average survival rate, and most patients have a poor disease prognosis because of delayed diagnosis. We used machine learning techniques to predict high-risk cases of OSCC by using salivary autoantibody levels and demographic and behavioral data.

METHODS

We collected the salivary samples of patients recruited from a teaching hospital between September 2008 and December 2012. Ten salivary autoantibodies, sex, age, smoking, alcohol consumption, and betel nut chewing were used to build prediction models for identifying patients with a high risk of OSCC. The machine learning algorithms applied in the study were logistic regression, random forest, support vector machine with the radial basis function kernel, eXtreme Gradient Boosting (XGBoost), and a stacking model. We evaluated the performance of the models by using the area under the receiver operating characteristic curve (AUC), with simulations conducted 100 times.

RESULTS

A total of 337 participants were enrolled in this study. The best predictive model was constructed using a stacking algorithm with original forms of age and logarithmic levels of autoantibodies (AUC = 0.795 ± 0.055). Adding autoantibody levels as a data source significantly improved the prediction capability (from 0.698 ± 0.06 to 0.795 ± 0.055, p < 0.001).

CONCLUSIONS

We successfully established a prediction model for high-risk cases of OSCC. This model can be applied clinically through an online calculator to provide additional personalized information for OSCC diagnosis, thereby reducing the disease morbidity and mortality rates.

Characterization of a cytoplasmic 2-Cys peroxiredoxin from Citrus sinensis and its potential role in protection from oxidative damage and wound healing

In present work, the recombinant cytoplasmic 2-Cys peroxiredoxin from Citrus sinensis (CsPrx) was purified and characterized. The peroxidase activity was examined with different substrates using DTT, a non-physiological electron donor. The conformational studies, in oxidized and reduced states, were performed using circular dichroism (CD) and fluorescence measurement. The CD analysis showed higher α-helical content for reduced state of the protein. The thermal stability studies of CsPrx by Differential Scanning Calorimetry (DSC) showed that oxidized state is more stable as compared to the reduced state of CsPrx. In vitro studies showed that the CsPrx provides a protective shield against ROS and free radicals that participate in the degradation of plasmid DNA. The pre-treatment of 10 μM CsPrx provide almost 100% protection against peroxide-mediated cell killing in the Vero cells. CsPrx showed significant cell proliferation and wound healing properties. The superior morphology of viable cells and wound closure was found at 20 μM CsPrx treated for 12 h. The results demonstrated that CsPrx is a multifaceted protein with a significant role in cell proliferation, wound healing and protection against hydrogen peroxide-induced cellular damage. This could be the first report of a plant peroxiredoxin being characterized for biomedical applications.

Comprehensive Analysis of the PRDXs Family in Head and Neck Squamous Cell Carcinoma

The peroxidase family of peroxiredoxins (PRDXs) plays a vital role in maintaining the intracellular balance of ROS. However, their function in head and neck squamous cell carcinoma (HNSCC) has not been investigated. We therefore explored the value of PRDXs in HNSCC. We found that the expression of PRDX1, PRDX4, and PRDX5 in HNSCC increased while the expression of PRDX2 decreased. Moreover, the high expression of PRDX4/5/6 indicated a poor prognosis. Lower expression of PRDX1/5 was linked to more immune cell infiltration, higher expression of immune-related molecules and a more likely response to anti-PD-1 treatment. Moreover, PRDX5 knockdown inhibited HNSCC cell proliferation, invasion and metastasis and it might promote apoptosis through its antioxidant property. Taken together, our study highlights the potential role of PRDXs in HNSCC. The function of PRDX5 in the development of HNSCC and the formation of the immune microenvironment makes it a promising potential therapeutic target.

Assessment of Potential Prognostic Value of Peroxiredoxin 1 in Oral Squamous Cell Carcinoma

Purpose

The role of the peroxiredoxin (PRDX) family in oral squamous cell carcinoma (OSCC) remains unclear. This study aimed to investigate the expression of PRDXs and their effects on the prognosis in OSCC.

Methods

The expression of PRDXs and their effects on prognosis were analysed in 216 OSCC samples from The Cancer Genome Atlas (TCGA) database. OSCC tissues and adjacent noncancerous tissues (ANTs) were obtained from 68 clinical patients. Quantitative real-time (qRT)-PCR, Western blot, and immunohistochemical (IHC) staining were used to verify the relationship between the expression level of PRDX1 and different clinical features. Gene set enrichment analysis (GSEA) was used to examine the molecular mechanism of PRDX1 in OSCC.

Results

PRDX1 was found to be the only gene in PRDX family that highly expressed in OSCC samples and affected the prognosis of patients with OSCC. PRDX1 expression was significantly related to tumor stage, lymphatic metastasis, and pathological grade. A nomogram consisting of tumor stage, N stage, and PRDX1 level was constructed. GSEA showed that high expression of PRDX1 involved many cancer-related molecular functions and signaling pathways.

Conclusion

PRDX1 may play an important role in the occurrence and development of OSCC, and may be a potential new target for OSCC treatment.