Functional Role of NRF2 in Cervical Carcinogenesis

Dual role of Nrf2 signaling in hepatocellular carcinoma: promoting development, immune evasion, and therapeutic challenges

Hepatocellular carcinoma (HCC) is the predominant form of liver cancer and ranks as the third leading cause of cancer-related mortality globally. The liver performs a wide range of tasks and is the primary organ responsible for metabolizing harmful substances and foreign compounds. Oxidative stress has a crucial role in growth and improvement of hepatocellular carcinoma (HCC). Nuclear factor erythroid 2 (1)-related factor 2 (Nrf2) is an element that regulates transcription located in the cytoplasm. It controls the balance of redox reactions by stimulating the expression of many genes that depend on antioxidant response elements. Nrf2 has contrasting functions in the normal, healthy liver and HCC. In the normal liver, Nrf2 provides advantageous benefits, while in HCC it promotes harmful effects that support the growth and survival of HCC. Continuous activation of Nrf2 has been detected in HCC and promotes its advancement and aggressiveness. In addition, Activation of Nrf2 may lead to immune evasion, weakening the immune cells' ability to attack tumors and thereby promoting tumor development. Furthermore, chemoresistance in HCC, which is considered a form of stress response to chemotherapy medications, significantly impedes the effectiveness of HCC treatment. Stress management is typically accomplished by activating specific signal pathways and chemical variables. One important element in the creation of chemoresistance in HCC is nuclear factor-E2-related factor 2 (Nrf2). Nrf2 is a transcription factor that regulates the activation and production of a group of genes that encode proteins responsible for protecting cells from damage. This occurs through the Nrf2/ARE pathway, which is a crucial mechanism for combating oxidative stress within cells.

NRF2 Suppression Enhances the Susceptibility of Pancreatic Cancer Cells, Miapaca-2 to Paclitaxel

Pancreatic cancer is one of the most deadly diseases, with a very high metastasis and low survival rate. High levels of NRF2 have been detected in numerous malignancies, including head, neck, lung, and colon cancers, promoting the expansion and survival of cancer cells and chemical resistance to stressful conditions and affecting the response to treatment. To evaluate the possibility that modulation of NRF2 expression could be effective in treating pancreatic cancer cells, we explored the effect of knockdown of the NRF2 gene by NRF2-specific siRNA and its influence in combination with paclitaxel on pancreatic cancer cells. Miapaca-2 cell line, due to the high expression of the NRF2 gene, was selected for this study. Then, Miapaca-2 cells in different groups were treated with NRF2 siRNA and paclitaxel separately and in combination. After that, cell viability was measured by MTT assay and apoptosis induction by Annexin V-FITC/PI staining test. Cell cycle and autophagy were examined by flow cytometry, and cell migration was assessed by wound-healing assay. Finally, the expression of genes involved in apoptosis, Bax, Caspase-3, Caspase-9, and genes related to migration pathway, MMP-2, and MMP-9 in different groups were measured using qRT-PCR. Combined use of NRF2-specific siRNA with paclitaxel significantly reduced NRF2 gene expression in pancreatic cancer cells. NRF2 siRNA transfection significantly reduced cell viability. In addition, paclitaxel combination therapy with NRF2 siRNA strengthens the anti-tumor effects, such as inhibiting cell migration and provoking apoptosis, and autophagy and the cell cycle arrest in the G2 phase. NRF2 suppression augmented the expression of Bax, Caspase-3, and Caspase-9 genes and lowered the expression of Bcl-2, MMP-2, and MMP-9 genes, which play crucial roles in the pathways of apoptosis and cell migration, respectively. NRF2 siRNA enhances the susceptibility of Miapaca-2 cells to paclitaxel in pancreatic cancer cells. Thereby, suppressing NRF2 in combination with paclitaxel can be a new and efficacious treatment approach in treating pancreatic cancer.

The protective effect of vinpocetine against Estradiol-benzoate induced cervical hyperkeratosis in female rats via modulation of SIRT1/Nrf2, and NLRP3 inflammasome

The current study was assigned to determine the putative preventive role of vinpocetine (VIN) in cervical hyperkeratosis (CHK) in female rats. Estradiol Benzoate (EB) was utilized in a dose f (60 μg/100 g, i.m) three times/week for 4 weeks to induce cervical hyperkeratosis. VIN was administered alone in a dose of (10 mg/kg/day, orally) for 4 weeks and in the presence of EB. Levels of malondialdehyde (MDA), total nitrites (NOx), reduced glutathione (GSH), interleukin-18 (IL-18), IL-1β, tumor necrosis factor-alpha (TNF-α) were measured in cervical tissue. The expression of NLRP3/GSDMD/Caspase-1, and SIRT1/Nrf2 was determined using ELISA. Cervical histopathological examination was also done. EB significantly raised MDA, NOx, TNF-α, IL-18, IL-1β, and GSDMD and up-regulated NLRP3/Caspase-1 proteins. However, GSH, SIRT1, and Nrf2 levels were reduced in cervical tissue. VIN significantly alleviates all biochemical and histopathological abnormalities. VIN considerably mitigates EB-induced cervical hyperkeratosis via NLRP3-induced pyroptosis and SIRT1/Nrf2 signaling pathway.

h r c s i a

The present study aimed to identify the possible effect of gentamicin (GEN) in Rats' Cervi. Estradiol Valerate (EV) was used to induce cervical hyperkeratosis. GEN was administered in absence of EV. Serum and cervical GEN concentration were determined. Levels of malondialdehyde (MDA), total nitrites/nitrate (NOx), reduced glutathione (GSH), tumor necrosis factor-α (TNF-α), sirtuin type 1 (Sirt1) and nuclear factor (erythroid-derived 2)-like-2 factors (Nrf2) were measured in cervix tissue. Expression of BAX and Bcl2 were determined. Cervical histopathological examination was done. EV and GEN significantly increased MDA, NOx, TNF-α and BAX/Bcl2 ratio with decrease in GSH, Nrf2 and Sirt1 levels in cervical tissue. Histopathological picture of diffuse and marked hyperkeratosis was detected in EV and GEN groups. In conclusion, GEN-induced cervical hyperkeratosis via induction of oxidative stress, inflammation and apoptosis.

The Role of the NRF2 Pathway in the Pathogenesis of Viral Respiratory Infections

In humans, acute and chronic respiratory infections caused by viruses are associated with considerable morbidity and mortality. Respiratory viruses infect airway epithelial cells and induce oxidative stress, yet the exact pathogenesis remains unclear. Oxidative stress activates the transcription factor NRF2, which plays a key role in alleviating redox-induced cellular injury. The transcriptional activation of NRF2 has been reported to affect both viral replication and associated inflammation pathways. There is complex bidirectional crosstalk between virus replication and the NRF2 pathway because virus replication directly or indirectly regulates NRF2 expression, and NRF2 activation can reversely hamper viral replication and viral spread across cells and tissues. In this review, we discuss the complex role of the NRF2 pathway in the regulation of the pathogenesis of the main respiratory viruses, including coronaviruses, influenza viruses, respiratory syncytial virus (RSV), and rhinoviruses. We also summarize the scientific evidence regarding the effects of the known NRF2 agonists that can be utilized to alter the NRF2 pathway.

The promoting effect and mechanism of Nrf2 on cell metastasis in cervical cancer

BACKGROUND

Cervical cancer (CC) has poor prognosis and high mortality rate for its metastasis during the disease progression. Epithelial-mesenchymal transition (EMT) and anoikis are initial and pivotal steps during the metastatic process. Although higher levels of Nrf2 are associated with aggressive tumor behaviors in cervical cancer, the detailed mechanism of Nrf2 in cervical cancer metastasis, especially EMT and anoikis, remains unclear.

METHODS

Immunohistochemistry (IHC) was used to examine Nrf2 expression in CC. Wound healing assay and transwell analysis were used to evaluate the migration ability of CC cells. Western blot, qTR-PCR and immunofluorescent staining were used to verify the expression level of Nrf2, the EMT associated markers and anoikis associated proteins. Flow cytometry assays and cell counting were used to detect the apoptosis of cervical cancer cells. The lung and lymph node metastatic mouse model were established for studies in vivo. The interaction between Nrf2 and Snail1 was confirmed by rescue-of-function assay.

RESULTS

When compared with cervical cancer patients without lymph node metastasis, Nrf2 was highly expressed in patients with lymph node metastasis. And Nrf2 was proved to enhance the migration ability of HeLa and SiHa cells. In addition, Nrf2 was positively correlated with EMT processes and negatively associated with anoikis in cervical cancer. In vivo, a xenograft assay also showed that Nrf2 facilitated both pulmonary and lymphatic distant metastasis of cervical cancer. Rescue-of-function assay further revealed the mechanism that Nrf2 impacted the metastasis of CC through Snail1.

CONCLUSION

Our fundings established Nrf2 plays a crucial role in the metastasis of cervical cancer by enhancing EMT and resistance to anoikis by promoting the expression of Snail1, with potential value as a therapeutic candidate.

New Visions on Natural Products and Cancer Therapy: Autophagy and Related Regulatory Pathways

Macroautophagy (autophagy) has been a highly conserved process throughout evolution and allows cells to degrade aggregated/misfolded proteins, dysfunctional or superfluous organelles and damaged macromolecules, in order to recycle them for biosynthetic and/or energetic purposes to preserve cellular homeostasis and health. Changes in autophagy are indeed correlated with several pathological disorders such as neurodegenerative and cardiovascular diseases, infections, cancer and inflammatory diseases. Conversely, autophagy controls both apoptosis and the unfolded protein response (UPR) in the cells. Therefore, any changes in the autophagy pathway will affect both the UPR and apoptosis. Recent evidence has shown that several natural products can modulate (induce or inhibit) the autophagy pathway. Natural products may target different regulatory components of the autophagy pathway, including specific kinases or phosphatases. In this review, we evaluated ~100 natural compounds and plant species and their impact on different types of cancers via the autophagy pathway. We also discuss the impact of these compounds on the UPR and apoptosis via the autophagy pathway. A multitude of preclinical findings have shown the function of botanicals in regulating cell autophagy and its potential impact on cancer therapy; however, the number of related clinical trials to date remains low. In this regard, further pre-clinical and clinical studies are warranted to better clarify the utility of natural compounds and their modulatory effects on autophagy, as fine-tuning of autophagy could be translated into therapeutic applications for several cancers.

Redox Imbalance and Its Metabolic Consequences in Tick-Borne Diseases

One of the growing global health problems are vector-borne diseases, including tick-borne diseases. The most common tick-borne diseases include Lyme disease, tick-borne encephalitis, human granulocytic anaplasmosis, and babesiosis. Taking into account the metabolic effects in the patient's body, tick-borne diseases are a significant problem from an epidemiological and clinical point of view. Inflammation and oxidative stress are key elements in the pathogenesis of infectious diseases, including tick-borne diseases. In consequence, this leads to oxidative modifications of the structure and function of phospholipids and proteins and results in qualitative and quantitative changes at the level of lipid mediators arising in both reactive oxygen species (ROS) and ROS enzyme-dependent reactions. These types of metabolic modifications affect the functioning of the cells and the host organism. Therefore, links between the severity of the disease state and redox imbalance and the level of phospholipid metabolites are being searched, hoping to find unambiguous diagnostic biomarkers. Assessment of molecular effects of oxidative stress may also enable the monitoring of the disease process and treatment efficacy.

HIF-1α Regulates the Progression of Cervical Cancer by Targeting YAP/TAZ

Cervical carcinoma is one of the serious pernicious cancers that influence women's health. Invasion and metastasis are the chief reason of poor prognosis of cervical carcinoma. Hypoxia-inducible factor-1α (HIF-1α) is a significant regulatory factor of intracellular oxygen supersession, and its expression or increased activity is closely related to the arise and expansion of various human tumors. However, the relationship between HIF-1α (hypoxia-inducible factor 1) and Hippo pathway target gene Yes-related protein (YAP) and transcriptional coactivator (TAZ) in cervical carcinoma remains unclear. Here, we studied the clinical correlation of HIF-1α and YAP/TAZ expression in normal tissues, cervical intraepithelial neoplasia (CIN), and cervical squamous cell carcinoma (CSCC). In order to analyze the role of HIF-1α in CCSC in vitro, SiHa cells with high expression of HIF-1α and C33a cells with low expression of HIF-1α were screened by detection. After transfection with lentivirus, HIF-1α levels were downregulated in SiHa cells and upregulated in C33a Cells, respectively. Then, the expression of HIF-1α in transfected cervical cancer cells Siha and C33a was detected by qRT-PCR and Western blot, and the expression of YAP/TAZ was detected in cervical squamous cell carcinoma cells after HIF-1α expression was altered. To explore HIF-1α role in cell proliferation, invasion, and metastasis, we examined the changes of cell function in cervical cancer cells with HIF-1α overexpression and inhibition by MTT assay, wound healing assay, Transwell test, and other cell function tests. At the same time, HIF-1α overexpression and HIF-1α inhibition cervical cancer cells were transplanted into nude mice, and tumors were isolated from the nude mice, and tumor volume and weight were observed. In conclusion, HIF-1α significantly promotes the proliferation, invasion, and migration of cervical carcinoma cells by upregulating YAP/TAZ. In addition, YAP/TAZ, the target gene of Hippo pathway, plays an important role in CCSC cells, pointing out that HIF-1α is provided with treatment potential for the treatment of CCSC.

Metabolic Response to Tick-Borne Encephalitis Virus Infection and Bacterial Co-Infections

Ticks are vectors of various pathogens, including tick-borne encephalitis virus and bacteria such as B. burgdorferi and A. phagocytophilum, causing infections/co-infections, which are still a diagnostic and therapeutic problem. Therefore, the aim of this study was to compare the effects of TBEV infection/bacterial co-infection on metabolic changes in the blood of patients before and after treatment. It was found that those infections promote plasma ROS enhanced generation and antioxidant defence reduction, especially in relation to glutathione and thioredoxin systems, despite the increased effectiveness of Nrf2 transcription factor in granulocytes. Observed oxidative stress promotes the oxidative modifications of phospholipids containing polyunsaturated fatty acids (LA, AA, EPA) with increased lipid peroxidation (estimated as 8-isoPGF2α, 4-HNE). It is accompanied by protein modifications measured as 4-HNE-protein adducts, carbonyl groups, dityrosine increase, and tryptophan level decrease, which promote structural and functional modification of the following transcription factors: Nrf2 and NFkB inhibitors. The lower level of 8-iso-PGF2α in co-infections indicates an impairment of the body’s ability to intensify inflammation and fight co-infections, while an increased level of Trx after therapy may contribute to the intensification of the inflammatory process. The obtained results indicate the potential possibility of using the assessed metabolic parameters to introduce targeted pharmacotherapy in cases of TBEV infections/bacterial co-infections.

The Expression of TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Can Be Controlled by the Antioxidant Orchestrator NRF2 in Human Carcinoma Cells

Hyperactivation of the KEAP1-NRF2 axis is a common molecular trait in carcinomas from different origin. The transcriptional program induced by NRF2 involves antioxidant and metabolic genes that render cancer cells more capable of dealing with oxidative stress. The TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) is an important regulator of glycolysis and the pentose phosphate pathway that was described as a p53 response gene, yet TIGAR expression is detected in p53-null tumors. In this study we investigated the role of NRF2 in the regulation of TIGAR in human carcinoma cell lines. Exposure of carcinoma cells to electrophilic molecules or overexpression of NRF2 significantly increased expression of TIGAR, in parallel to the known NRF2 target genes NQO1 and G6PD. The same was observed in TP53KO cells, indicating that NRF2-mediated regulation of TIGAR is p53-independent. Accordingly, downregulation of NRF2 decreased the expression of TIGAR in carcinoma cell lines from different origin. As NRF2 is essential in the bone, we used mouse primary osteoblasts to corroborate our findings. The antioxidant response elements for NRF2 binding to the promoter of human and mouse TIGAR were described. This study provides the first evidence that NRF2 controls the expression of TIGAR at the transcriptional level.

Nuclear factor erythroid 2-related factor 2 in human papillomavirus-related cancers

High-risk human papillomavirus (HR-HPV) infection is a necessary cause for the development of cervical cancer. Moreover, HR-HPV is also associated with cancers in the anus, vagina, vulva, penis and oropharynx. HR-HPVs target and modify the function of different cell biomolecules, such as glucose, amino acids, lipids and transcription factors (TF), such as p53, nuclear factor erythroid 2-related factor 2 (Nrf2), among others. The latter is a master TF that maintains redox homeostasis. Nrf2 also induces the transcription of genes associated with cell detoxification. Since both processes are critical for cell physiology, Nrf2 deregulation is associated with cancer development. Nrf2 is a crucial molecule in HPV-related cancer development but underexplored. Moreover, Nrf2 activation is also associated with resistance to chemotherapy and radiotherapy in these cancers. This review focusses on the importance of Nrf2 during HPV-related cancer development, resistance to therapy and potential therapies associated with Nrf2 as a molecular target.

Robust Prognostic Subtyping of Muscle-Invasive Bladder Cancer Revealed by Deep Learning-Based Multi-Omics Data Integration

Muscle-invasive bladder cancer (MIBC) is the most common urinary system carcinoma associated with poor outcomes. It is necessary to develop a robust classification system for prognostic prediction of MIBC. Recently, increasing omics data at different levels of MIBC were produced, but few integration methods were used to classify MIBC that reflects the patient’s prognosis. In this study, we constructed an autoencoder based deep learning framework to integrate multi-omics data of MIBC and clustered samples into two different subgroups with significant overall survival difference (P = 8.11 × 10^-5). As an independent prognostic factor relative to clinical information, these two subtypes have some significant genomic differences. Remarkably, the subtype of poor prognosis had significant higher frequency of chromosome 3p deletion. Immune decomposition analysis results showed that these two MIBC subtypes had different immune components including macrophages M1, resting NK cells, regulatory T cells, plasma cells, and naïve B cells. Hallmark gene set enrichment analysis was performed to investigate the functional character difference between these two MIBC subtypes, which revealed that activated IL-6/JAK/STAT3 signaling, interferon-alpha response, reactive oxygen species pathway, and unfolded protein response were significantly enriched in upregulated genes of high-risk subtype. We constructed MIBC subtyping models based on multi-omics data and single omics data, respectively, and internal and external validation datasets showed the robustness of the prediction model as well as its ability of prognosis (P < 0.05 in all datasets). Finally, through bioinformatics analysis and immunohistochemistry experiments, we found that KRT7 can be used as a biomarker reflecting MIBC risk.

Inhibition of the NRF2/KEAP1 Axis: A Promising Therapeutic Strategy to Alter Redox Balance of Cancer Cells

Significance: The nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (NRF2/KEAP1) pathway is a crucial and highly conserved defensive system that is required to maintain or restore the intracellular homeostasis in response to oxidative, electrophilic, and other types of stress conditions. The tight control of NRF2 function is maintained by a complex network of biological interactions between positive and negative regulators that ultimately ensure context-specific activation, culminating in the NRF2-driven transcription of cytoprotective genes. Recent Advances: Recent studies indicate that deregulated NRF2 activation is a frequent event in malignant tumors, wherein it is associated with metabolic reprogramming, increased antioxidant capacity, chemoresistance, and poor clinical outcome. On the other hand, the growing interest in the modulation of the cancer cells' redox balance identified NRF2 as an ideal therapeutic target. Critical Issues: For this reason, many efforts have been made to identify potent and selective NRF2 inhibitors that might be used as single agents or adjuvants of anticancer drugs with redox disrupting properties. Despite the lack of specific NRF2 inhibitors still represents a major clinical hurdle, the researchers have exploited alternative strategies to disrupt NRF2 signaling at different levels of its biological activation. Future Directions: Given its dualistic role in tumor initiation and progression, the identification of the appropriate biological context of NRF2 activation and the specific clinicopathological features of patients cohorts wherein its inactivation is expected to have clinical benefits, will represent a major goal in the field of cancer research. In this review, we will briefly describe the structure and function of the NRF2/ KEAP1 system and some of the most promising NRF2 inhibitors, with a particular emphasis on natural compounds and drug repurposing. Antioxid. Redox Signal. 34, 1428-1483.

P62/SQSTM1/Keap1/NRF2 Axis Reduces Cancer Cells Death-Sensitivity in Response to Zn(II)-Curcumin Complex

The hyperactivation of nuclear factor erythroid 2 p45-related factor 2 (NRF2), frequently found in many tumor types, can be responsible for cancer resistance to therapies and poor patient prognosis. Curcumin has been shown to activate NRF2 that has cytotprotective or protumorigenic roles according to tumor stage. The present study aimed at investigating whether the zinc–curcumin Zn(II)–curc compound, which we previously showed to display anticancer effects through multiple mechanisms, could induce NRF2 activation and to explore the underlying molecular mechanisms. Biochemical studies showed that Zn(II)–curc treatment increased the NRF2 protein levels along with its targets, heme oxygenase-1 (HO-1) and p62/SQSTM1, while markedly reduced the levels of Keap1 (Kelch-like ECH-associated protein 1), the NRF2 inhibitor, in the cancer cell lines analyzed. The silencing of either NRF2 or p62/SQSTM1 with specific siRNA demonstrated the crosstalk between the two molecules and that the knockdown of either molecule increased the cancer cell sensitivity to Zn(II)–curc-induced cell death. This suggests that the crosstalk between p62/SQSTM1 and NRF2 could be therapeutically exploited to increase cancer patient response to therapies.

New insights into the role of the Nrf2 signaling pathway in green tea catechin applications

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a transcriptional signaling pathway that plays a crucial role in numerous clinical complications. Pivotal roles of Nrf2 have been proved in cancer, autoimmune diseases, neurodegeneration, cardiovascular diseases, diabetes mellitus, renal injuries, respiratory conditions, gastrointestinal disturbances, and general disorders related to oxidative stress, inflammation, apoptosis, gelatinolysis, autophagy, and fibrogenesis processes. Green tea catechins as a rich source of phenolic compounds can deal with various clinical problems and manifestations. In this review, we attempted to focus on intervention between green tea catechins and Nrf2. Green tea catechins especially epigallocatechin gallate (EGCG) elucidated the protective role of Nrf2 and its downstream molecules in various disorders through Keap-1, HO-1, NQO-1, GPx, GCLc, GCLm, NF-kB cross-link, kinases, and apoptotic proteins. Subsequently, we compiled an updated expansions of the Nrf2 role as a gate to manage and protect different disorders and feasible indications of green tea catechins through this signaling pathway. The present review highlighted recent evidence-based data in silico, in vitro, and in vivo studies on an outline for future clinical trials.

Regulation of Canonical Oncogenic Signaling Pathways in Cancer via DNA Methylation

Disruption of signaling pathways that plays a role in the normal development and cellular homeostasis may lead to the dysregulation of cellular signaling and bring about the onset of different diseases, including cancer. In addition to genetic aberrations, DNA methylation also acts as an epigenetic modifier to drive the onset and progression of cancer by mediating the reversible transcription of related genes. Although the role of DNA methylation as an alternative driver of carcinogenesis has been well-established, the global effects of DNA methylation on oncogenic signaling pathways and the presentation of cancer is only emerging. In this article, we introduced a differential methylation parsing pipeline (MethylMine) which mined for epigenetic biomarkers based on feature selection. This pipeline was used to mine for biomarkers, which presented a substantial difference in methylation between the tumor and the matching normal tissue samples. Combined with the Data Integration Analysis for Biomarker discovery (DIABLO) framework for machine learning and multi-omic analysis, we revisited the TCGA DNA methylation and RNA-Seq datasets for breast, colorectal, lung, and prostate cancer, and identified differentially methylated genes within the NRF2-KEAP1/PI3K oncogenic pathway, which regulates the expression of cytoprotective genes, that serve as potential therapeutic targets to treat different cancers.

NFE2L2 Is a Potential Prognostic Biomarker and Is Correlated with Immune Infiltration in Brain Lower Grade Glioma: A Pan-Cancer Analysis

Nuclear factor, erythroid 2 like 2 (NFE2L2, NRF2) is a transcription factor that regulates various antioxidant enzymes. It plays a vital physiological role in regulating oxidative stress and inflammatory response. However, the roles of NFE2L2 in human cancers are still unclear. Our study is aimed at analyzing the prognostic value of NFE2L2 in pan-cancer and at revealing the relationship between NFE2L2 expression and tumor immunity. The present study revealed that NFE2L2 was abnormally expressed and significantly correlated with mismatch repair (MMR) gene mutation levels and DNA methyltransferase expression in human pan-cancer. In particular, pan-cancer survival analysis indicated that NFE2L2 expression was associated with adverse outcomes-overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI)-in adrenocortical carcinoma (ACC), brain lower grade glioma (LGG), and pancreatic adenocarcinoma (PAAD) patients. A positive relationship was also found between NFE2L2 expression and immune infiltration, including B cells, CD4+ T cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells, especially in breast invasive carcinoma (BRCA), colon adenocarcinoma (COAD), kidney renal clear cell carcinoma (KIRC), LGG, liver hepatocellular carcinoma (LIHC), and prostate adenocarcinoma (PRAD). Additionally, NFE2L2 expression was positively correlated with the immune score and the expression of immune checkpoint markers in LGG. In conclusion, these results indicate that transcription factor NFE2L2 is a potential prognostic biomarker and is correlated with immune infiltration in LGG.

Enhanced Expression of ABCB1 and Nrf2 in CD133-Positive Cancer Stem Cells Associates with Doxorubicin Resistance

The precise mechanism about drug resistance of cancer stem cells (CSCs) has not yet been completely understood. Based on the expression of CD44 and CD133, two well-recognized cell surface markers for CSC identification, we tried to separate HCT8 colorectal cancer cells into different subpopulations and then investigated how the expression of CD44 and CD133 associated with doxorubicin (DXR) resistance. Interestingly, DXR resistance was observed in CD44⁺CD133⁺ (P < 0.01vs. all other subpopulations), but not in CD44⁺CD133⁻ cells. CD44⁺CD133⁺ cells also showed an enhanced expression of ABCB1 and drug efflux ability (P < 0.001vs. all other subpopulations), but verapamil, an inhibitor of ABCB1, only partially mitigated the DXR resistance. Independent on the accumulation of DXR, lower level of reactive oxygen species and higher expression of Nrf2 were detected in CD44⁺CD133⁺ than CD44⁺CD133⁻ cells (P < 0.05). Unexpectedly, silencing CD133 by siRNA only partially enhanced the cytotoxicity of DXR, but did not obviously change the expression of ABCB1 and the accumulation of DXR in CD44⁺CD133⁺ cells. Complex mechanisms, including drug excretion and redox regulation, are likely involved in the DXR resistance of CD133-positive cells, suggesting the difficulty of drug resistance problem in cancer chemotherapy.

Human Papillomavirus 16 E7 Promotes EGFR/PI3K/AKT1/NRF2 Signaling Pathway Contributing to PIR/NF-κB Activation in Oral Cancer Cells

A subset of oral carcinomas is etiologically related to high-risk human papillomavirus (HR-HPV) infection, with HPV16 being the most frequent HR-HPV type found in these carcinomas. The oncogenic role of HR-HPV is strongly dependent on the overexpression of E6 and E7 oncoproteins, which, in turn, induce p53 and pRb degradation, respectively. Additionally, it has been suggested that HR-HPV oncoproteins are involved in the regulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), inducing cancer progression and metastasis. Previously, we reported that HPV16 E7 oncoprotein promotes Pirin upregulation resulting in increased epithelial–mesenchymal transition (EMT) and cell migration, with Pirin being an oxidative stress sensor and activator of NF-κB. In this study, we demonstrate the mechanism by which HPV16 E7-mediated Pirin overexpression occurs by promoting EGFR/PI3K/AKT1/NRF2 signaling, thus causing PIR/NF-κB activation in oral tumor cells. Our results demonstrate a new mechanism by which E7 contributes to oral cancer progression, proposing PIR as a potential new therapeutic target.

The Impact of the Ubiquitin System in the Pathogenesis of Squamous Cell Carcinomas

The ubiquitin system is a dynamic regulatory pathway controlling the activity, subcellular localization and stability of a myriad of cellular proteins, which in turn affects cellular homeostasis through the regulation of a variety of signaling cascades. Aberrant activity of key components of the ubiquitin system has been functionally linked with numerous human diseases including the initiation and progression of human tumors. In this review, we will contextualize the importance of the two main components of the ubiquitin system, the E3 ubiquitin ligases (E3s) and deubiquitinating enzymes (DUBs), in the etiology of squamous cell carcinomas (SCCs). We will discuss the signaling pathways regulated by these enzymes, emphasizing the genetic and molecular determinants underlying their deregulation in SCCs.

RIPK1 polymorphisms alter the susceptibility to cervical Cancer among the Uyghur population in China

Background

RIPK1 (receptor-interacting protein kinase-1) plays a role in cancer development, whereas no clear studies focused on the cervical cancer. The objective of this study was to evaluate the relationship between RIPK1 polymorphisms and cervical cancer risk among the Uyghur population.

Methods

We performed a case-control study including 342 cervical cancer patients and 498 age-matched healthy controls. Four RIPK1 genetic variants (rs6907943, rs2077681, rs9503400 and rs17548629) were genotyped with Agena MassARRAY platform. The associations between RIPK1 polymorphisms and cervical cancer risk were assessed under Binary logistic regression models. False discovery rate (FDR) was used to improve the results reliability.

Results

The results showed rs2077681 was significantly associated with cervical cancer risk under various genetic models (codominant: OR = 3.14, 95% CI = 1.40–7.07, p = 0.006, FDR-p = 0.018; recessive: OR = 3.20, 95% CI = 1.43–7.16, p = 0.005, FDR-0.018). The stratified analysis indicated that the relationships of rs6907946, rs9503400 and rs17548629 with cervical cancer risk were statistically significant in the subgroup of clinical stage (p < 0.05).

Conclusion

Our findings demonstrated that RIPK1 polymorphisms were associated with cervical cancer susceptibility among the Uyghur population in China, and RIPK1 polymorphisms might be involved in the development of cervical cancer.

The Role of Nrf2 Activity in Cancer Development and Progression

Nrf2 is a transcription factor that stimulates the expression of genes which have antioxidant response element-like sequences in their promoter. Nrf2 is a cellular protector, and this principle applies to both normal cells and malignant cells. While healthy cells are protected from DNA damage induced by reactive oxygen species, malignant cells are defended against chemo- or radiotherapy. Through our literature search, we found that Nrf2 activates several oncogenes unrelated to the antioxidant activity, such as Matrix metallopeptidase 9 (MMP-9), B-cell lymphoma 2 (BCL-2), B-cell lymphoma-extra large (BCL-xL), Tumour Necrosis Factor α (TNF-α), and Vascular endothelial growth factor A (VEGF-A). We also did a brief analysis of The Cancer Genome Atlas (TCGA) data of lung adenocarcinoma concerning the effects of radiation therapy and found that the therapy-induced Nrf2 activation is not universal. For instance, in the case of recurrent disease and radiotherapy, we observed that, for the majority of Nrf2-targeted genes, there is no change in expression level. This proves that the universal, axiomatic rationale that Nrf2 is activated as a response to chemo- and radiation therapy is wrong, and that each scenario should be carefully evaluated with the help of Nrf2-targeted genes. Moreover, there were nine genes involved in lipid peroxidation, which showed underexpression in the case of new radiation therapy: ADH1A, ALDH3A1, ALDH3A2, ADH1B, GPX2, ADH1C, ALDH6A1, AKR1C3, and NQO1. This may relate to the fact that, while some studies reported the co-activation of Nrf2 and other oncogenic signaling pathways such as Phosphoinositide 3-kinases (PI3K), mitogen-activated protein kinase (MAPK), and Notch1, other reported the inverse correlation between Nrf2 and the tumor-promoter Transcription Factor (TF), Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Lastly, Nrf2 establishes its activity through interactions at multiple levels with various microRNAs. MiR-155, miR-144, miR-28, miR-365-1, miR-93, miR-153, miR-27a, miR-142, miR-29-b1, miR-340, and miR-34a, either through direct repression of Nrf2 messenger RNA (mRNA) in a Kelch-like ECH-associated protein 1 (Keap1)-independent manner or by enhancing the Keap1 cellular level, inhibit the Nrf2 activity. Keap1–Nrf2 interaction leads to the repression of miR-181c, which is involved in the Nuclear factor kappa light chain enhancer of activated B cells (NF-κB) signaling pathway. Nrf2’s role in cancer prevention, diagnosis, prognosis, and therapy is still in its infancy, and the future strategic planning of Nrf2-based oncological approaches should also consider the complex interaction between Nrf2 and its various activators and inhibitors.

Inhibition of SGK1 confers vulnerability to redox dysregulation in cervical cancer

Cervical cancer has poor prognosis and patients are often diagnosed at advanced stages of the disease with limited treatment options. There is thus an urgent need for the discovery of new therapeutic strategies in cervical cancer. The activation of SGK1 has been linked to the development of various cancer types but little is known about the role of SGK1 in cervical cancer and its potential as a therapeutic target. Here we report that SGK1 is an antioxidative factor that promotes survival of cervical cancer cells. Gene set enrichment analysis of RNA-Seq data reveals a strong inverse association between SGK1 and oxidative phosphorylation. Consistently, inhibition of SGK1 via siRNA or pharmacological inhibitor GSK650394 induces ROS and cytotoxicity upon H₂O₂ stress. Further analysis of clinical data associates SGK1 with gene expression signatures regulated by the antioxidant transcription factor NRF2 in cervical cancer. Mechanistically, SGK1 activation exerts antioxidant effect through induction of c-JUN-dependent NRF2 expression and activity. Importantly, we find that inhibition of SGK1 confers vulnerability to melatonin as a pro-oxidant, resulting in ROS over-accumulation and consequently enhanced cell cytotoxicity. We further demonstrate that combined use of GSK650394 and melatonin yields substantial regression of cervical tumors in vivo. This work opens new perspectives on the potential of SGK1 inhibitors as sensitizing agents to enable the design of therapeutically redox-modulating strategies against cervical cancer.

Oxidative stress in cervical cancer pathogenesis and resistance to therapy

Cervical cancer (CC) is one of the most common cancers among females, and it is most notable in developing countries. The exact etiology of CC is poorly understood; but, smoking, oral contraceptives, immunosuppression, and infection with human papillomavirus (HPV) may increase the risk of CC. There is also an association between CC and oxidative stress. Oxidative stress is caused by a disturbed oxidant-antioxidant balance in favor of the former, leading to an excessive generation of free radicals, particularly reactive oxygen species (ROS), and subsequently to biological damages. Thus, redox enzymatic and nonenzymatic regulators are required to maintain the redox homeostasis. Dysregulated antioxidants system and the pathogenic role of oxidative stress in CC have been investigated in several clinical and preclinical studies. In this study, we reviewed studies that have addressed the cross-talk between oxidative stress and CC pathogenesis and resistance to therapy.

Pharmacological Applications of Nrf2 Inhibitors as Potential Antineoplastic Drugs

Oxidative stress (OS) is associated with many diseases ranging from cancer to neurodegenerative disorders. Nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) is one of the most effective cytoprotective controller against OS. Modulation of Nrf2 pathway constitutes a remarkable strategy in the antineoplastic treatments. A big number of Nrf2-antioxidant response element activators have been screened for use as chemo-preventive drugs in OS associated diseases like cancer even though activation of Nrf2 happens in a variety of cancers. Research proved that hyperactivation of the Nrf2 pathway produces a situation that helps the survival of normal as well as malignant cells, protecting them against OS, anticancer drugs, and radiotherapy. In this review, the modulation of the Nrf2 pathway, anticancer activity and challenges associated with the development of an Nrf2-based anti-cancer treatment approaches are discussed.

Curcumin induces p53-independent inactivation of Nrf2 during oxidative stress-induced apoptosis

The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) is a master regulator of a battery of antioxidant and detoxificant genes with cytoprotective function. Since Nrf2 inactivation is necessary for the complete execution of apoptosis in the presence of extensive cellular damage caused by oxidative stress, constant activation of Nrf2 may protect tumoral cells from apoptosis. The tumor suppressor gene p53 has been suggested to participate in apoptosis-related repression of Nrf2. Thus, we studied the inactivation of Nrf2 during oxidant-induced apoptosis in a p53 dysfunctional cellular model. Using curcumin dose-response assay and time-response assay in an immortalized lymphoblastoid cell line (control line 45), we observed a time-dependent increase in apoptotic markers such as deoxyribonucleic acid (DNA) fragmentation, phosphatidylserine exposure, and caspase-3, caspase-9 and poly (ADP-ribose) polymerases (PARP) cleavage. Interestingly, at early times of exposure to a proapoptotic dose of curcumin (15 μM), we observed nuclear accumulation of Nrf2 and the expression of Nrf2 target genes, whereas at late exposure times we found a reduction of total and nuclear protein levels of Nrf2 as well as downregulation of Nrf2 target genes in the absence of p53 activation. These data suggest that apoptosis-related inactivation of Nrf2 could occur in a p53 dysfunctional background, opening the possible occurrence of p53-independent mechanism to explain Nrf2 inactivation during apoptosis.

Allicin suppresses the migration and invasion in cervical cancer cells mainly by inhibiting NRF2

Emerging evidence has demonstrated the antitumor activity of allicin in various tumors. However, little study has been carried out on the functional role of allicin in cervical cancer. Our data showed that allicin suppressed cervical cancer cell viability in a time- and dose-dependent manner. Allicin treatment could reverse H2O2-induced reactive oxygen species accumulation. Meanwhile, levels of glutathione and superoxide dismutase were increased, but malondialdehyde was decreased after allicin incubation for 48 h. Furthermore, TUNEL staining showed that H2O2 treatment induced cell apoptosis, but allicin treatment could decrease cell apoptosis. Western blot assay showed that allicin could suppress the expression of nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase 1. We also showed that NRF2 prompted SiHa cell proliferation and reduced SiHa cell apoptosis. More importantly, allicin-inactivated phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling could be partially reversed by overexpressing of NRF2. We also evaluated cell apoptosis in SiHa cells transfected with plasmid NRF2. Our data showed that allicin-induced cell apoptosis (43.5±3.8%) could largely be abolished by upregulation of NRF2 (12.3±2.08%). In summary, our data showed allicin was effective in suppressing the malignant phenotype of cervical cancer cells mainly by inhibiting the expression of NRF2, showing the potential clinical benefits of allicin in cervical cancer patients.

Expression of Keap1 and Nrf2 in diffuse large B-cell lymphoma and its clinical significance

The present study investigated the expression and clinical significance of kelch-like ECH-associated protein 1 (Keap1) and nuclear factor erythroid-2-related factor-2 (Nrf2) expression in diffuse large B-cell lymphoma (DLBCL). These proteins were detected by immunohistochemistry in 39 DLBCL cases and 17 cases of reactive lymph node hyperplasia, and their association with the clinicopathological features of DLBCL patients was analyzed. In DLBCL, the percentage of cells with positive staining for Keap1 and Nrf2 was 46.2 and 35.9%, respectively, which was significantly higher than that in reactive lymph node hyperplasia (17.7 and 5.9%, respectively). There was no correlation between Keap1 and Nrf2 expression according to a Spearman rank correlation analysis (r=0.272; P>0.05). Keap1 and Nrf2 expression was associated with the international prognostic index and Ann-Arbor clinical stage (P<0.05), and Keap1 and Nrf2 expression was higher in DLBCL patients with stage III–IV (68.4 and 52.6%, respectively) compared with in those with stage I–II (25.0 and 20.0%, respectively). The aberrant expression of Keap1 and Nrf2 in DLBCL suggests that these factors may have crucial roles in the development and progression of the disease, and may therefore be used as prognostic indicators.

The Progress of Methylation Regulation in Gene Expression of Cervical Cancer

Cervical cancer is one of the most common gynecological tumors in females, which is closely related to high-rate HPV infection. Methylation alteration is a type of epigenetic decoration that regulates the expression of genes without changing the DNA sequence, and it is essential for the progression of cervical cancer in pathogenesis while reflecting the prognosis and therapeutic sensitivity in clinical practice. Hydroxymethylation has been discovered in recent years, thus making 5-hmC, the more stable marker, attract more attention in the field of methylation research. As markers of methylation, 5-hmC and 5-mC together with 5-foC and 5-caC draw the outline of the reversible cycle, and 6-mA takes part in the methylation of RNA, especially mRNA. Furthermore, methylation modification participates in ncRNA regulation and histone decoration. In this review, we focus on recent advances in the understanding of methylation regulation in the process of cervical cancer, as well as HPV and CIN, to identify the significant impact on the prospect of overcoming cervical cancer.

NRF2 addiction in cancer cells

The Kelch‐like ECH‐associated protein 1/nuclear factor erythroid‐derived 2‐like 2 (KEAP1‐NRF2) system is a pivotal defense mechanism against oxidative and electrophilic stress. Although transient NRF2 activation in response to stress is beneficial for health, persistent NRF2 activation in cancer cells has deleterious effects on cancer‐bearing hosts by conferring therapeutic resistance and aggressive tumorigenic activity on cancer cells. Because NRF2 increases the antioxidant and detoxification capability of cancer cells, persistently high levels of NRF2 activity enhance therapeutic resistance of cancer cells. NRF2 also drives metabolic reprogramming to establish cellular metabolic processes that are advantageous for cell proliferation in cooperation with other oncogenic pathways. As a result of these advantages, cancer cells with persistent activation of NRF2 often develop “NRF2 addiction” and show malignant phenotypes leading to poor prognoses in cancer patients. Inhibition of NRF2 is a promising therapeutic approach for NRF2‐addicted cancers and NRF2 inhibitors are being actively developed. However, giving systemic NRF2 inhibitors might have undesirable effects on cancer‐bearing hosts, considering the central roles of NRF2 in cytoprotection. To avoid these side‐effects, new therapeutic targets besides NRF2 for NRF2‐addicted cancers have been actively explored. This review introduces recent studies describing the development and characterization of NRF2‐addicted cancers, as well as their potential therapeutic targets. Expected advances in diagnostic and therapeutic interventions for NRF2‐addicted cancers are also discussed.

RNF113A promotes the proliferation, migration and invasion, and is associated with a poor prognosis of esophageal squamous cell carcinoma

Ring finger protein 113A (RNF113A) possesses a C3HC4 zinc finger domain and this domain is found in E3 ubiquitin ligase and is involved in tumorigenesis. To date, and at least to the best of our knowledge, there are no studies available which have investigated RNF113A in cancer. Thus, this study aimed to explore the role of RNF113A in the development of esophageal squamous cell carcinoma (ESCC). For this purpose, paraffin-embedded samples from 117 patients with ESCC were selected, as well as 41 pairs of fresh-frozen ESCC and adjacent normal tissue samples. RNF113A expression was examined by immunohistochemistry and reverse transcription-quantitative PCR (RT-qPCR). RNF113A was overexpressed or silenced in the EC9706 and Eca109 cells. The cells were examined for cell cycle progression, apoptosis, invasiveness and migration. Xenograft tumors were also created in mice using the Eca109 cells. Tumor differentiation (P=0.008) and T classification (P<0.001) were found to be significantly associated with RNF113A expression. No statistically significant association was observed between RNF113A expression and sex, age, histological type, tumor location and lymph node metastasis (N classification). Kaplan-Meier analysis revealed that the patients with ESCC with ahigh expression of RNF113A had a lower survival rate than those with a low expression (P=0.002). Multivariate analysis revealed that RNF113A expression (HR=2.406; 95% CI, 1.301-4.449, P=0.005) was independently associated with overall survival in patients with ESCC. The overexpression of RNF113A promoted proliferation, migration, and invasiveness of ESCC cell lines in vitro, and RNF113A silencing reversed these malignant behaviors. RNF113A knockdown inhibited tumor growth in vivo. Thus, these results indicate that RNF113A promotes the proliferation, migration and invasiveness of ESCC cell lines. RNF113A expression in ESCC is this associated with a poor prognosis of affected patients.

A small molecule targeting glutathione activates Nrf2 and inhibits cancer cell growth through promoting Keap-1S-glutathionylation and inducing apoptosis

The level of glutathione (GSH) is increased in many cancer cells. Consuming intracellular GSH by chemical small molecules that specifically target GSH is a new strategy to treat cancer. Recently, we synthesized and proved that a new compound 2-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)cyclohexa-2,5-diene-1,4-dione (PBQC) could target to and consume intracellular GSH specifically, but, it is not clear if PBQC can affect cancer cell growth and the activity of the nuclear factor-erythroid 2-related factor 2 (Nrf2) which is a key factor involved in regulation of cancer cell growth. In this study, we addressed these questions. We found that PBQC suppressed cancer cell growth through increasing the activity of Nrf2, while it did not inhibit normal vascular endothelial cell growth. Furthermore, we demonstrated that PBQC can cause Keap-1 protein S-glutathionylation and promote Nrf2 nuclear translocation as well as the expression of pro-apoptosis genes. As a result, the cancer cells underwent apoptosis. Here, we provide a new Nrf2 activator, PBQC that can promote the expressions of pro-apoptosis genes downstream Nrf2. The data suggest that PBQC is a potential lead-compound for development of new anti-cancer drugs.

The level of glutathione (GSH) is increased in many cancer cells.

Nrf2 inhibition affects cell cycle progression during early mouse embryo development

Brusatol, a quassinoid isolated from the fruit of Bruceajavanica, has recently been shown to inhibit nuclear factor erythroid 2-related factor 2 (Nrf2) via Keap1-dependent ubiquitination and proteasomal degradation or protein synthesis. Nrf2 is a transcription factor that regulates the cellular defense response. Most studies have focused on the effects of Nrf2 in tumor development. Here, the critical roles of Nrf2 in mouse early embryonic development were investigated. We found that brusatol treatment at the zygotic stage prevented the early embryo development. Most embryos stayed at the two-cell stage after 5 days of culture (P < 0.05). This effect was associated with the cell cycle arrest, as the mRNA level of CDK1 and cyclin B decreased at the two-cell stage after brusatol treatment. The embryo development potency was partially rescued by the injection of Nrf2 CRISPR activation plasmid. Thus, brusatol inhibited early embryo development by affecting Nrf2-related cell cycle transition from G₂ to M phase that is dependent on cyclin B-CDK1 complex.

Isodeoxyelephantopin induces protective autophagy in lung cancer cells via Nrf2-p62-keap1 feedback loop

Isodeoxyelephantopin (ESI), isolated from Elephantopus scaber L. has been reported to exert anticancer effects. In this study, we aimed to investigate whether and how cancer cells exert protective responses against ESI treatment. Confocal fluorescence microscopy showed that ESI significantly induced autophagy flux in the lung cancer cells expressing mCherry-EGFP-LC3 reporter. Treatment of the cells with ESI increased the expression levels of the autophagy markers including LC3-II, ATG3 and Beclin1 in a dose-dependent manner. Pretreatment with autophagy inhibitor 3-methyladenine (3-MA) not only attenuated the effects of ESI on autophagy, but also enhanced the effects of ESI on cell viability and apoptosis. Mechanistically, the SILAC quantitative proteomics coupled with bioinformatics analysis revealed that the ESI-regulated proteins were mainly involved in Nrf2-mediated oxidative stress response. We found that ESI induced the nuclear translocation of Nrf2 for activating the downstream target genes including HO-1 and p62 (SQSTM1). More importantly, ESI-induced p62 could competitively bind with Keap1, and releases Nrf2 to activate downstream target gene p62 as a positive feedback loop, therefore promoting autophagy. Furthermore, knockdown of Nrf2 or p62 could abrogate the ESI-induced autophagy and significantly enhanced the anticancer effect of ESI. Taken together, we demonstrated that ESI can sustain cell survival by activating protective autophagy through Nrf2-p62-keap1 feedback loop, whereas targeting this regulatory axis combined with ESI treatment may be a promising strategy for anticancer therapy.

Partition-Defective 3 (PARD3) Regulates Proliferation, Apoptosis, Migration, and Invasion in Esophageal Squamous Cell Carcinoma Cells

Background

Altered expression of partition-defective 3 (PARD3), a polarity-related gene associated with oncogenesis, has been identified in some cancers, but the role of PARD3 in esophageal squamous cell carcinoma (ESCC) remains unclear.

Material/Methods

PARD3 expression in Eca109 cells was silenced using siRNA and overexpressed using an expression vector. We investigated the role of PARD3 in ESCC growth and motility to evaluate its potential role in ESCC. Transwell assay was used to evaluated cell migration and invasion. PARD3 protein expression was assessed by Western blot.

Results

PARD3 overexpression promoted apoptosis, impaired proliferation, and inhibited cell migration and invasion in Eca109 cells, while PARD3 silencing promoted proliferation and increased migration and invasion. Overexpression of PARD3 exerted its antitumor activity in vitro by impairing cell proliferation, inducing apoptosis, and inhibiting migration and invasion of Eca109 cells, suggesting that PARD3 might play a tumor suppressor role in ESCC.

Conclusions

Overexpression of PARD3 could be a promising new therapeutic intervention against ESCC.

Cervical Cancer Cell Line Secretome Highlights the Roles of Transforming Growth Factor-Beta-Induced Protein ig-h3, Peroxiredoxin-2, and NRF2 on Cervical Carcinogenesis

Cancer cells acquire unique secretome compositions that contribute to tumor development and metastasis. The aim of our study was to elucidate the biological processes involved in cervical cancer, by performing a proteomic analysis of the secretome from the following informative cervical cell lines: SiHa (HPV16+), HeLa (HPV18+), C33A (HPV-), and HCK1T (normal). Proteins were analyzed by 2D gel electrophoresis coupled to MALDI-TOF-MS. Enrichment of secreted proteins with characteristic profiles for each cell line was followed by the identification of differentially expressed proteins. Particularly, transforming growth factor-beta-induced protein ig-h3 (Beta ig-h3) and peroxiredoxin-2 (PRDX2) overexpression in the secretome of cancer cell lines was detected and confirmed by Western blot. Bioinformatics analysis identified the transcription factor NRF2 as a regulator of differentially expressed proteins in the cervical cancer secretome. NRF2 levels were measured by both Western blot and Multiple Reaction Monitoring (MRM) in the total cell extract of the four cell lines. NRF2 was upregulated in SiHa and C33A compared to HCK1T. In conclusion, the secreted proteins identified in cervical cancer cell lines indicate that aberrant NRF2-mediated oxidative stress response (OSR) is a prominent feature of cervical carcinogenesis.

Regulation of Keap1-Nrf2 signaling: The role of epigenetics

Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (NFE2L2/Nrf2) signaling pathway is a pivotal player in the antioxidant response to oxidative and electrophilic stress and can play a role in many human diseases. Activation or inhibition of Nrf2 has been an approach to treating many diseases such as cancer and regulation of this pathway has been thoroughly studied. Recently, epigenetics has emerged as another layer for regulating Keap1-Nrf2. Epigenetics modification is defined as heritable changes to gene expression without changing DNA sequence and various modifications have been found to be involved in regulating Keap1-Nrf2. Therefore, targeting these epigenetic changes on Keap1-Nrf2 provides a potential pathway for modulating Keap1-Nrf2 to treat disease. In this review, several important and recent findings on epigenetic regulation and perspectives on Keap1-Nrf2 are discussed and shared.