Nrf1 and Nrf2 transcription factors regulate androgen receptor transactivation in prostate cancer cells

Salvia miltiorrhiza Bunge Ameliorates Benign Prostatic Hyperplasia through Regulation of Oxidative Stress via Nrf-2/HO-1 Activation

Oxidative stress is a key factor in the pathogenesis of benign prostatic hyperplasia (BPH) that leads to inflammation. This study aimed to evaluate the ameliorative effects of Salvia miltiorrhiza Bunge extract (HLT-101) on BPH through the regulation of oxidative stress and inflammation. A testosterone propionate (TP)-induced BPH rat model was orally administered HLT-101 (20, 40, or 80 mg/kg), and its effects on oxidative stress- and inflammation-related gene expression were examined. Further, HLT-101 was assessed for its effect on reactive oxygen species (ROS) levels and Nrf-2/HO-1 signaling pathways in BPH-1 cells. HLT-101 decreased testosterone-induced excessive free radical production and inflammatory factor activation. Moreover, HLT-101 treatment significantly decreased the intracellular ROS level in the TNF-α and IFN-γ treated BPH-1 cells through the activation of Nrf-2. In addition, HLT-101 treatment inhibited the NF-κB pathway and androgen receptor (AR) signaling, which is highly linked to the pathogenesis of BPH. Therefore, HLT-101 has the potential to be an effective treatment reagent for BPH because of its ability to reduce inflammation and oxidative stress via Nrf-2/HO-1 signaling.

Precision nutrition to reset virus-induced human metabolic reprogramming and dysregulation (HMRD) in long-COVID

SARS-CoV-2, the etiological agent of COVID-19, is devoid of any metabolic capacity; therefore, it is critical for the viral pathogen to hijack host cellular metabolic machinery for its replication and propagation. This single-stranded RNA virus with a 29.9 kb genome encodes 14 open reading frames (ORFs) and initiates a plethora of virus-host protein-protein interactions in the human body. These extensive viral protein interactions with host-specific cellular targets could trigger severe human metabolic reprogramming/dysregulation (HMRD), a rewiring of sugar-, amino acid-, lipid-, and nucleotide-metabolism(s), as well as altered or impaired bioenergetics, immune dysfunction, and redox imbalance in the body. In the infectious process, the viral pathogen hijacks two major human receptors, angiotensin-converting enzyme (ACE)-2 and/or neuropilin (NRP)-1, for initial adhesion to cell surface; then utilizes two major host proteases, TMPRSS2 and/or furin, to gain cellular entry; and finally employs an endosomal enzyme, cathepsin L (CTSL) for fusogenic release of its viral genome. The virus-induced HMRD results in 5 possible infectious outcomes: asymptomatic, mild, moderate, severe to fatal episodes; while the symptomatic acute COVID-19 condition could manifest into 3 clinical phases: (i) hypoxia and hypoxemia (Warburg effect), (ii) hyperferritinemia ('cytokine storm'), and (iii) thrombocytosis (coagulopathy). The mean incubation period for COVID-19 onset was estimated to be 5.1 days, and most cases develop symptoms after 14 days. The mean viral clearance times were 24, 30, and 39 days for acute, severe, and ICU-admitted COVID-19 patients, respectively. However, about 25-70% of virus-free COVID-19 survivors continue to sustain virus-induced HMRD and exhibit a wide range of symptoms that are persistent, exacerbated, or new 'onset' clinical incidents, collectively termed as post-acute sequelae of COVID-19 (PASC) or long COVID. PASC patients experience several debilitating clinical condition(s) with >200 different and overlapping symptoms that may last for weeks to months. Chronic PASC is a cumulative outcome of at least 10 different HMRD-related pathophysiological mechanisms involving both virus-derived virulence factors and a multitude of innate host responses. Based on HMRD and virus-free clinical impairments of different human organs/systems, PASC patients can be categorized into 4 different clusters or sub-phenotypes: sub-phenotype-1 (33.8%) with cardiac and renal manifestations; sub-phenotype-2 (32.8%) with respiratory, sleep and anxiety disorders; sub-phenotype-3 (23.4%) with skeleto-muscular and nervous disorders; and sub-phenotype-4 (10.1%) with digestive and pulmonary dysfunctions. This narrative review elucidates the effects of viral hijack on host cellular machinery during SARS-CoV-2 infection, ensuing detrimental effect(s) of virus-induced HMRD on human metabolism, consequential symptomatic clinical implications, and damage to multiple organ systems; as well as chronic pathophysiological sequelae in virus-free PASC patients. We have also provided a few evidence-based, human randomized controlled trial (RCT)-tested, precision nutrients to reset HMRD for health recovery of PASC patients.

Unravelling the role of NFE2L1 in stress responses and related diseases

The nuclear factor erythroid 2 (NF-E2)-related factor 1 (NFE2L1, also known as Nrf1) is a highly conserved transcription factor that belongs to the CNC-bZIP subfamily. Its significance lies in its control over redox balance, proteasome activity, and organ integrity. Stress responses encompass a series of compensatory adaptations utilized by cells and organisms to cope with extracellular or intracellular stress initiated by stressful stimuli. Recently, extensive evidence has demonstrated that NFE2L1 plays a crucial role in cellular stress adaptation by 1) responding to oxidative stress through the induction of antioxidative responses, and 2) addressing proteotoxic stress or endoplasmic reticulum (ER) stress by regulating the ubiquitin-proteasome system (UPS), unfolded protein response (UPR), and ER-associated degradation (ERAD). It is worth noting that NFE2L1 serves as a core factor in proteotoxic stress adaptation, which has been extensively studied in cancer and neurodegeneration associated with enhanced proteasomal stress. In these contexts, utilization of NFE2L1 inhibitors to attenuate proteasome "bounce-back" response holds tremendous potential for enhancing the efficacy of proteasome inhibitors. Additionally, abnormal stress adaptations of NFE2L1 and disturbances in redox and protein homeostasis contribute to the pathophysiological complications of cardiovascular diseases, inflammatory diseases, and autoimmune diseases. Therefore, a comprehensive exploration of the molecular basis of NFE2L1 and NFE2L1-mediated diseases related to stress responses would not only facilitate the identification of novel diagnostic and prognostic indicators but also enable the identification of specific therapeutic targets for NFE2L1-related diseases.

Co-expression network analysis for the identification of potential prostate cancer genes and in vitro confirmation of their expression in cell model in the presence of Staphylococcal tsst-1 gene

Prostate cancer has arisen as an important life-threatening malignancy in males worldwide. Therefore, it is important to study underlying molecular pathways to be able to proposed appropriate a novel pathway of apoptosis in prostate cancer. This study aimed to explore the molecular effects of Staphylococcal tsst-1 gene on PC3 cell line apoptosis by in silico and in vitro studies. In this work, the differential expression of genes in prostate cancer was predicted by analyzing the public dataset GSE132063. Then, the pcDNA3.1 (+) vector was used to transfer tsst-1 gene to the PC3 cells and its effects was investigated using flow cytometry and qPCR. Co-expression network analysis indicated that lncRNAs had strong relationship with apoptosis genes in prostate cancer. Results of protein-protein docking indicated that BCL2L11, GRAMD3 and EGR1 interacted with tsst-1. Finally, the flow cytometry results showed that transfection by pcDNA3.1 (+)- tsst-1 could increase cellular death rates (48.15%) compared with the pcDNA3.1 (+) groups (6.35%); and the expression levels of GRAMD3, EGR1, BCL2L11 and PLAC4 were dysregulated in tsst-1 -transfected PC3 compared with empty-transfected PC3 (p < .05). In conclusion, our data will provide a novel landscape to understanding the mechanism of Staphylococcal tsst-1 gene on the PC3 cells apoptosis pathways.

Role of Natural and Synthetic Compounds in Modulating NRF2/KEAP1 Signaling Pathway in Prostate Cancer

Prostate cancer is the second most common cancer in men worldwide. Prostate cancer can be treated by surgery or active surveillance when early diagnosed but, when diagnosed at an advanced or metastatic stage, radiation therapy or androgen-deprivation therapy is needed to reduce cancer progression. However, both of these therapies can cause prostate cancer resistance to treatment. Several studies demonstrated that oxidative stress is involved in cancer occurrence, development, progression and treatment resistance. The nuclear factor erythroid 2-related factor 2 (NRF2)/KEAP1 (Kelch-Like ECH-Associated Protein 1) pathway plays an important role in protecting cells against oxidative damage. Reactive oxygen species (ROS) levels and NRF2 activation can determine cell fate. In particular, toxic levels of ROS lead physiological cell death and cell tumor suppression, while lower ROS levels are associated with carcinogenesis and cancer progression. On the contrary, a high level of NRF2 promotes cell survival related to cancer progression activating an adaptive antioxidant response. In this review, we analyzed the current literature regarding the role of natural and synthetic compounds in modulating NRF2/KEAP1 signaling pathway in prostate cancer.

Role of Olive Bioactive Compounds in Respiratory Diseases

Respiratory diseases recently became the leading cause of death worldwide, due to the emergence of COVID-19. The pathogenesis of respiratory diseases is centred around inflammation and oxidative stress. Plant-based alongside synthetic drugs were considered as therapeutics due to their proven nutraceutical value. One such example is the olive, which is a traditional symbol of the MedDiet. Olive bioactive compounds are enriched with antioxidant, anti-inflammatory, anticancer and antiviral properties. However, there are few studies relating to the beneficial effect of olive bioactive compounds on respiratory diseases. A vague understanding of its molecular action, dosage and bioavailability limits its usefulness for clinical trials about respiratory infections. Hence, our review aims to explore olive bioactive compound's antioxidant, anti-inflammatory and antiviral properties in respiratory disease defence and treatment. Molecular insight into olive compounds' potential for respiratory system protection against inflammation and ensuing infection is also presented. Olive bioactive compounds mainly protect the respiratory system by subsiding proinflammatory cytokines and oxidative stress.

Sex differences in antioxidant defence and the regulation of redox homeostasis in physiology and pathology

Reactive oxygen species (ROS) is a term that defines a group of unstable compounds derived from exogenous sources or endogenous metabolism. Under physiological conditions, low levels of ROS play a key role in the regulation of signal transduction- or transcription-mediated cellular responses. In contrast, excessive and uncontrolled loading of ROS results in a pathological state known as oxidative stress (OS), a leading contributor to aging and a pivotal factor for the onset and progression of many disorders. Evolution has endowed cells with an antioxidant system involved in stabilizing ROS levels to a specific threshold, preserving ROS-induced signalling function and limiting negative side effects. In mammals, a great deal of evidence indicates that females defence against ROS is more proficient than males, determining a longer lifespan and lower incidence of most chronic diseases. In this review, we will summarize the most recent sex-related differences in the regulation of redox homeostasis. We will highlight the peculiar aspects of the antioxidant defence in sex-biased diseases whose onset or progression is driven by OS, and we will discuss the molecular, genetic, and evolutionary determinants of female proficiency to cope with ROS.

Small-molecule metabolites in SARS-CoV-2 treatment: a comprehensive review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has quickly spread all over the world. In this respect, traditional medicinal chemistry, repurposing, and computational approaches have been exploited to develop novel medicines for treating this condition. The effectiveness of chemicals and testing methods in the identification of new promising therapies, and the extent of preparedness for future pandemics, have been further highly advantaged by recent breakthroughs in introducing noble small compounds for clinical testing purposes. Currently, numerous studies are developing small-molecule (SM) therapeutic products for inhibiting SARS-CoV-2 infection and replication, as well as managing the disease-related outcomes. Transmembrane serine protease (TMPRSS2)-inhibiting medicinal products can thus prevent the entry of the SARS-CoV-2 into the cells, and constrain its spreading along with the morbidity and mortality due to the coronavirus disease 2019 (COVID-19), particularly when co-administered with inhibitors such as chloroquine (CQ) and dihydroorotate dehydrogenase (DHODH). The present review demonstrates that the clinical-stage therapeutic agents, targeting additional viral proteins, might improve the effectiveness of COVID-19 treatment if applied as an adjuvant therapy side-by-side with RNA-dependent RNA polymerase (RdRp) inhibitors.

5-Hydroxyeicosatetraenoic Acid Controls Androgen Reduction in Diverse Types of Human Epithelial Cells

Androgens regulate broad physiologic and pathologic processes, including external genitalia development, prostate cancer progression, and anti-inflammatory effects in both cancer and asthma. In prostate cancer, several lines of evidence have implicated dietary and endogenous fatty acids in cell invasion, angiogenesis, and treatment resistance. However, the role of fatty acids in steroidogenesis and the mechanisms by which alterations in this pathway occur are not well understood. Here, we show that, of a panel of fatty acids tested, arachidonic acid and its specific metabolite 5-hydroxyeicosatetraenoic acid (5-HETE) regulate androgen metabolism. Arachidonic acid is metabolized to 5-HETE and reduces androgens by inducing aldo-keto reductase (AKR) family members AKR1C2 and AKR1C3 expression in human prostate, breast, and lung epithelial cells. Finally, we provide evidence that these effects require the expression of the antioxidant response sensor, nuclear factor erythroid 2-related factor 2 (Nrf2). Our findings identify an interconnection between conventional fatty acid metabolism and steroid metabolism that has broad relevance to androgen physiology and inflammatory regulation.

The ERα-NRF2 signalling axis promotes bicalutamide resistance in prostate cancer

BACKGROUND

Bicalutamide is a nonsteroidal antiandrogen widely used as a first-line clinical treatment for advanced prostate cancer (PCa). Although patients initially show effective responses to bicalutamide treatment, resistance to bicalutamide frequently occurs and leads to the development of castration-resistant PCa (CRPC). This research investigated the roles of the oestrogen receptor α (ERα)-nuclear factor E2-related factor 2 (NRF2) signalling pathway in bicalutamide resistance in PCa cells.

METHODS

We performed bioinformatic analysis and immunohistochemical staining on normal and cancerous prostate tissue to evaluate ERα and NRF2 expression and their correlation. Gene expression and localization in PCa cell lines were further investigated using real-time reverse transcription PCR/Western blotting and immunofluorescence staining. We treated PCa cells with the ER inhibitor tamoxifen and performed luciferase reporter assays and chromatin immunoprecipitation (ChIP) assays to understand ERα-dependent NRF2 expression. Overexpression and knockdown of ERα and NRF2 were used to explore the potential role of the ERα-NRF2 signalling axis in bicalutamide resistance in PCa cells.

RESULTS

We found that the expression of ERα and NRF2 was positively correlated and was higher in human CRPC tissues than in primary PCa tissues. Treatment with oestrogen or bicalutamide increased the expression of ERα and NRF2 as well as NRF2 target genes in PCa cell lines. These effects were blocked by pretreatment with tamoxifen. ChIP assays demonstrated that ERα directly binds to the oestrogen response element (ERE) in the NRF2 promoter. This binding led to increased transcriptional activity of NRF2 in a luciferase reporter assay. Activation of the ERα-NRF2 signalling axis increased the expression of bicalutamide resistance-related genes. Inhibition of this signalling axis by knockdown of ERα or NRF2 downregulated the expression of bicalutamide resistance-related genes and inhibited the proliferation and migration of PCa cells.

CONCLUSIONS

We demonstrated the transcriptional interaction between ERα and NRF2 in CRPC tissues and cell lines by showing the direct binding of ERα to the ERE in the NRF2 promoter under oestrogen treatment. Activation of the ERα-NRF2 signalling axis contributes to bicalutamide resistance in PCa cells, suggesting that the ERα-NRF2 signalling axis is a potential therapeutic target for CRPC. Video Abstract.

NRF2: A crucial regulator for mitochondrial metabolic shift and prostate cancer progression

Metabolic alterations are a common survival mechanism for prostate cancer progression and therapy resistance. Oxidative stress in the cellular and tumor microenvironment dictates metabolic switching in the cancer cells to adopt, prosper and escape therapeutic stress. Therefore, regulation of oxidative stress in tumor cells and in the tumor-microenvironment may enhance the action of conventional anticancer therapies. NRF2 is the master regulator for oxidative stress management. However, the overall oxidative stress varies with PCa clinical stage, metabolic state and therapy used for the cancer. In agreement, the blanket use of NRF2 inducers or inhibitors along with anticancer therapies cause adverse effects in some preclinical cancer models. In this review, we have summarized the levels of oxidative stress, metabolic preferences and NRF2 activity in the different stages of prostate cancer. We also propose condition specific ways to use NRF2 inducers or inhibitors along with conventional prostate cancer therapies. The significance of this review is not only to provide a detailed understanding of the mechanism of action of NRF2 to regulate oxidative stress-mediated metabolic switching by prostate cancer cells to escape the radiation, chemo, or hormonal therapies, and to grow aggressively, but also to provide a potential therapeutic method to control aggressive prostate cancer growth by stage specific proper use of NRF2 regulators.

The Prostate Cancer Androgen Receptor Cistrome in African American Men Associates with Upregulation of Lipid Metabolism and Immune Response

African-American (AA) men are more likely to be diagnosed with and die from prostate cancer than European American (EA) men. Despite the central role of the androgen receptor (AR) transcription factor in prostate cancer, little is known about the contribution of epigenetics to observed racial disparities. We performed AR chromatin immunoprecipitation sequencing on primary prostate tumors from AA and EA men, finding that sites with greater AR binding intensity in AA relative to EA prostate cancer are enriched for lipid metabolism and immune response genes. Integration with transcriptomic and metabolomic data demonstrated coinciding upregulation of lipid metabolism gene expression and increased lipid levels in AA prostate cancer. In a metastatic prostate cancer cohort, upregulated lipid metabolism associated with poor prognosis. These findings offer the first insights into ancestry-specific differences in the prostate cancer AR cistrome. The data suggest a model whereby increased androgen signaling may contribute to higher levels of lipid metabolism, immune response, and cytokine signaling in AA prostate tumors. Given the association of upregulated lipogenesis with prostate cancer progression, our study provides a plausible biological explanation for the higher incidence and aggressiveness of prostate cancer observed in AA men.

SIGNIFICANCE

With immunotherapies and inhibitors of metabolic enzymes in clinical development, the altered lipid metabolism and immune response in African-American men provides potential therapeutic opportunities to attenuate racial disparities in prostate cancer.

Combination of the NRF2 Inhibitor and Autophagy Inhibitor Significantly Inhibited Tumorigenicity of Castration-Resistant Prostate Cancer

Prostate cancer (PCa) is the most frequent cancer in men. Developing new treatment methods for CRPC will be a significant challenge in the clinical treatment of PCa. In conclusion, the results of this study show that NRF2 is downregulated in untreated PCa samples compared to normal PCa samples; however, it was upregulated in mCRPC samples compared to HSPC samples. These results demonstrated that NRF2 may serve as a tumor suppressor in tumorigenesis but promote PCa androgen-independent transferring after ADT treatment. Bioinformatics analysis showed that NRF2 was related to multiple signaling, such as the AGE-RAGE pathway, MAPK pathway, NF-kappa B signaling, PI3K-Akt signaling pathway, and VEGF signaling pathway. Moreover, we revealed that the NRF2 inhibitor significantly inhibited tumorigenicity of CRPC cells in vitro. Of note, combination of the NRF2 inhibitor and autophagy inhibitor had a more significantly suppressive role than either ML385 or CQ, indicating that combination of CQ (autophagy inhibitor) and ML385 (NRF2 inhibitor) is a potential treatment of CRPC. Finally, we conformed that high levels of autophagy regulators LC3B, ULK1, and beclin1 significantly correlated to longer PSA recurrence-free survival time. We think that this study could provide more evidence to confirm that NRF2 is a crucial regulator and targeting NRF2 and autophagy is a potential therapy option for CRPC.

Oxidative Stress and Redox-Dependent Signaling in Prostate Cancer

Tumor emergence and progression is complicated by the dual role of reactive oxygen species (ROS). Low concentrations of ROS are essential for many intracellular metabolic processes and cell proliferation, while excessive ROS generation disrupts the mechanisms of cancer suppression, leading to the cell damage and death. A long-term imbalance in the ROS/antioxidant ratio and upregulation of the ROS generation due to the reduced efficacy of the antioxidant defense system cause chronic oxidative stress resulting in the damage of proteins, lipid, and DNA molecules and cancer development. Numerous data demonstrate that prostate cancer (the most common cancer in males) is associated with the development of oxidative stress. However, the reasons for the emergence of prostate cancer, as well as changes in the redox signaling and cellular redox homeostasis in this disease, are still poorly understood. The review examines the role of prooxidant and antioxidant enzyme systems, the imbalance in their activity leading to the oxidative stress development, changes in the key components of redox signaling, and the role of microRNAs in the modulation of redox status of cancer cells in prostate cancer.

Microplastic consumption induces inflammatory signatures in the colon and prolongs a viral arthritis

Global microplastic (MP) contamination and the effects on the environment are well described. However, the potential for MP consumption to affect human health remains controversial. Mice consuming ≈80 μg/kg/day of 1 μm polystyrene MPs via their drinking water showed no weight loss, nor were MPs detected in internal organs. The microbiome was also not significantly changed. MP consumption did lead to small transcriptional changes in the colon suggesting plasma membrane perturbations and mild inflammation. Mice were challenged with the arthritogenic chikungunya virus, with MP consumption leading to a significantly prolonged arthritic foot swelling that was associated with elevated Th1, NK cell and neutrophil signatures. Immunohistochemistry also showed a significant increase in the ratio of neutrophils to monocyte/macrophages. The picture that emerges is reminiscent of enteropathic arthritis, whereby perturbations in the colon are thought to activate innate lymphoid cells that can inter alia migrate to joint tissues to promote inflammation.

The Role of NRF2 in Bone Metabolism - Friend or Foe?

Bone metabolism is closely related to oxidative stress. As one of the core regulatory factors of oxidative stress, NRF2 itself and its regulation of oxidative stress are both involved in bone metabolism. NRF2 plays an important and controversial role in the regulation of bone homeostasis in osteoblasts, osteoclasts and other bone cells. The role of NRF2 in bone is complex and affected by several factors, such as its expression levels, age, sex, the presence of various physiological and pathological conditions, as well as its interaction with certains transcription factors that maintain the normal physiological function of the bone tissue. The properties of NRF2 agonists have protective effects on the survival of osteogenic cells, including osteoblasts, osteocytes and stem cells. Activation of NRF2 directly inhibits osteoclast differentiation by resisting oxidative stress. The effects of NRF2 inhibition and hyperactivation on animal skeleton are still controversial, the majority of the studies suggest that the presence of NRF2 is indispensable for the acquisition and maintenance of bone mass, as well as the protection of bone mass under various stress conditions. More studies show that hyperactivation of NRF2 may cause damage to bone formation, while moderate activation of NRF2 promotes increased bone mass. In addition, the effects of NRF2 on the bone phenotype are characterized by sexual dimorphism. The efficacy of NRF2-activated drugs for bone protection and maintenance has been verified in a large number of in vivo and in vitro studies. Additional research on the role of NRF2 in bone metabolism will provide novel targets for the etiology and treatment of osteoporosis.

Role of NRF2 and Sirtuin activators in COVID-19

COVID-19 is a pandemic requiring immediate solution for treatment because of its complex pathophysiology. Exploration of novel targets and thus treatment will be life savers which is the need of the hour. 2 host factors- TMPRSS2 and ACE2 are responsible for the way the virus will enter and replicate in the host. Also NRF2 is an important protein responsible for its anti-inflammatory role by multiple mechanisms of action like inhibition of NF-kB, suppression of pro-inflammatory genes, etc. NRF2 is deacetylated by Sirtuins and therefore both have a direct association. Absence of SIRT indicates inhibition of NRF2 expression and thus no anti-oxidative and anti-inflammatory protection for the cell. Therefore, we propose that NRF2 activators and/or SIRT activators can be evaluated to check their efficacy in ameliorating the symptoms of COVID-19.

Oxidative stress and redox signaling in CRPC progression: therapeutic potential of clinically-tested Nrf2-activators

Androgen deprivation therapy (ADT) is the mainstay regimen in patients with androgen-dependent prostate cancer (PCa). However, the selection of androgen-independent cancer cells leads to castrate resistant prostate cancer (CRPC). The aggressive phenotype of CRPC cells underscores the need to elucidate mechanisms and therapeutic strategies to suppress CRPC outgrowth. Despite ADT, the activation of androgen receptor (AR) transcription factor continues via crosstalk with parallel signaling pathways. Understanding of how these signaling cascades are initiated and amplified post-ADT is lacking. Hormone deprivation can increase oxidative stress and the resultant reactive oxygen species (ROS) may activate both AR and non-AR signaling. Moreover, ROS-induced inflammatory cytokines may further amplify these redox signaling pathways to augment AR function. However, clinical trials using ROS quenching small molecule antioxidants have not suppressed CRPC progression, suggesting that more potent and persistent suppression of redox signaling in CRPC cells will be needed. The transcription factor Nrf2 increases the expression of numerous antioxidant enzymes and downregulates the function of inflammatory transcription factors, e.g., nuclear factor kappa B. We documented that Nrf2 overexpression can suppress AR-mediated transcription in CRPC cell lines. Furthermore, two Nrf2 activating agents, sulforaphane (a phytochemical) and bardoxolone-methyl (a drug in clinical trial) suppress AR levels and sensitize CRPC cells to anti-androgens. These observations implicate the benefits of potent Nrf2-activators to suppress the lethal signaling cascades that lead to CRPC outgrowth. This review article will address the redox signaling networks that augment AR signaling during PCa progression to CRPC, and the possible utility of Nrf2-activating agents as an adjunct to ADT.

Targeting immunometabolism to treat COVID-19

The COVID-19 crisis has emphasised the need for antiviral therapies to combat current and future viral zoonoses. Recent studies have shown that immune cells such as macrophages are the main contributors to the inflammatory response seen in the later inflammatory phase of COVID-19. Immune cells in the context of a viral infection such as SARS-CoV-2 undergo metabolic reprogramming to elicit these pro-inflammatory effector functions. The evidence of metabolic reprogramming in COVID-19 offers opportunities for metabolites with immunomodulatory properties to be investigated as potential therapies to combat this hyper-inflammatory response. Recent research indicates that the metabolite itaconate, previously known to be broadly antibacterial, may have both antiviral and immunomodulatory potential. Furthermore, low itaconate levels have shown to correlate with COVID-19 disease severity, potentially implicating its importance in the disease. The antiviral potential of itaconate has encouraged researchers to synthesise itaconate derivatives for antiviral screening, with some encouraging results. This review summarises the antiviral and immunomodulatory potential of immunometabolic modulators including metformin, peroxisome proliferator-activated receptor agonists and TEPP-46 as well as itaconate, and its derivatives and their potential use as broad spectrum anti-viral agents.

NRF2 function in osteocytes is required for bone homeostasis and drives osteocytic gene expression

Osteocytes, the most abundant bone cell type, are derived from osteoblasts through a process in which they are embedded in an osteoid. We previously showed that nutrient restriction promotes the osteocyte transcriptional program and is associated with increased mitochondrial biogenesis. Here, we show that increased mitochondrial biogenesis increase reactive oxygen species (ROS) levels and consequently, NRF2 activity during osteocytogenesis. NRF2 activity promotes osteocyte-specific expression of Dmp1, Mepe, and Sost in IDG-SW3 cells, primary osteocytes, and osteoblasts, and in murine models with Nfe2l2 deficiency in osteocytes or osteoblasts. Moreover, ablation of Nfe2l2 in osteocytes or osteoblasts generates osteopenia and increases osteoclast numbers with marked sexual dimorphism. Finally, treatment with dimethyl fumarate prevented the deleterious effects of ovariectomy in trabecular bone masses of mice and restored osteocytic gene expression. Altogether, we uncovered the role of NRF2 activity in osteocytes during the regulation of osteocyte gene expression and maintenance of bone homeostasis.

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ROS levels and NRF2 activity are increased during osteocytogenesis.

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NRF2 drives osteocyte specification and activate the transcription of osteocyte-specific genes.

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NRF2 in osteocytes has a fundamental role in bone homeostasis and its deletion induces osteopenia.

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Activation of NRF2 with dimethyl fumarate prevents osteopenia induced by ovariectomy.

De Novo Assembly of the Northern Cardinal (Cardinalis cardinalis) Genome Reveals Candidate Regulatory Regions for Sexually Dichromatic Red Plumage Coloration

Northern cardinals (Cardinalis cardinalis) are common, mid-sized passerines widely distributed in North America. As an iconic species with strong sexual dichromatism, it has been the focus of extensive ecological and evolutionary research, yet genomic studies investigating the evolution of genotype-phenotype association of plumage coloration and dichromatism are lacking. Here we present a new, highly-contiguous assembly for C. cardinalis We generated a 1.1 Gb assembly comprised of 4,762 scaffolds, with a scaffold N50 of 3.6 Mb, a contig N50 of 114.4 kb and a longest scaffold of 19.7 Mb. We identified 93.5% complete and single-copy orthologs from an Aves dataset using BUSCO, demonstrating high completeness of the genome assembly. We annotated the genomic region comprising the CYP2J19 gene, which plays a pivotal role in the red coloration in birds. Comparative analyses demonstrated non-exonic regions unique to the CYP2J19 gene in passerines and a long insertion upstream of the gene in C. cardinalis Transcription factor binding motifs discovered in the unique insertion region in C. cardinalis suggest potential androgen-regulated mechanisms underlying sexual dichromatism. Pairwise Sequential Markovian Coalescent (PSMC) analysis of the genome reveals fluctuations in historic effective population size between 100,000-250,000 in the last 2 millions years, with declines concordant with the beginning of the Pleistocene epoch and Last Glacial Period. This draft genome of C. cardinalis provides an important resource for future studies of ecological, evolutionary, and functional genomics in cardinals and other birds.

Roles of Reactive Oxygen Species in Biological Behaviors of Prostate Cancer

Prostate cancer (PCa), known as a heterogenous disease, has a high incidence and mortality rate around the world and seriously threatens public health. As an inevitable by-product of cellular metabolism, reactive oxygen species (ROS) exhibit beneficial effects by regulating signaling cascades and homeostasis. More and more evidence highlights that PCa is closely associated with age, and high levels of ROS are driven through activation of several signaling pathways with age, which facilitate the initiation, development, and progression of PCa. Nevertheless, excessive amounts of ROS result in harmful effects, such as genotoxicity and cell death. On the other hand, PCa cells adaptively upregulate antioxidant genes to detoxify from ROS, suggesting that a subtle balance of intracellular ROS levels is required for cancer cell functions. The current review discusses the generation and biological roles of ROS in PCa and provides new strategies based on the regulation of ROS for the treatment of PCa.

The Nrf2 Activator (DMF) and Covid-19: Is there a Possible Role?

INTRODUCTION

COVID-19 is a new viral illness that can affect the lungs and airways with lethal consequences leading to the death of the patients. The ACE2 receptors were widely disturbed among body tissues such as lung, kidney, small intestine, heart, and others in different percent and considered a target for the nCOVID-19 virus. S-protein of the virus was binding to ACE2 receptors caused downregulation of endogenous anti-viral mediators, upregulation of NF-κB pathway, ROS and pro-apoptotic protein. Nrf2 was a transcription factor that's play a role in generation of anti-oxidant enzymes.

AIM

To describe and establish role of Nrf2 activators for treatment COVID-19 positive patients.

METHODS

We used method of analysis of the published papers with described studies about COVID-19 connected with pharmacological issues and aspects which are included in global fighting against COVID-19 infection, and how using DMF (Nrf2 activator) in clinical trial for nCOVID-19 produce positive effects in patients for reduce lung alveolar cells damage.

RESULTS

we are found that Nrf2 activators an important medication that's have a role in reduce viral pathogenesis via inhibit virus entry through induce SPLI gene expression as well as inhibit TRMPSS2, upregulation of ACE2 that's make a competition with the virus on binding site, induce gene expression of anti-viral mediators such as RIG-1 and INFs, induce anti-oxidant enzymes, also they have a role in inhibit NF-κB pathway, inhibit both apoptosis proteins and gene expression of TLRs.

CONCLUSION

We are concluded that use DMF (Nrf2 activator) in clinical trial for nCOVID-19 positive patients to reduce lung alveolar cells damage.

Overall survival prediction of non-small cell lung cancer by integrating microarray and clinical data with deep learning

Non-small cell lung cancer (NSCLC) is one of the most common lung cancers worldwide. Accurate prognostic stratification of NSCLC can become an important clinical reference when designing therapeutic strategies for cancer patients. With this clinical application in mind, we developed a deep neural network (DNN) combining heterogeneous data sources of gene expression and clinical data to accurately predict the overall survival of NSCLC patients. Based on microarray data from a cohort set (614 patients), seven well-known NSCLC biomarkers were used to group patients into biomarker- and biomarker+ subgroups. Then, by using a systems biology approach, prognosis relevance values (PRV) were then calculated to select eight additional novel prognostic gene biomarkers. Finally, the combined 15 biomarkers along with clinical data were then used to develop an integrative DNN via bimodal learning to predict the 5-year survival status of NSCLC patients with tremendously high accuracy (AUC: 0.8163, accuracy: 75.44%). Using the capability of deep learning, we believe that our prediction can be a promising index that helps oncologists and physicians develop personalized therapy and build the foundation of precision medicine in the future.

Bardoxolone-Methyl (CDDO-Me) Suppresses Androgen Receptor and Its Splice-Variant AR-V7 and Enhances Efficacy of Enzalutamide in Prostate Cancer Cells

Androgen receptor (AR) signaling is fundamental to prostate cancer (PC) progression, and hence, androgen deprivation therapy (ADT) remains a mainstay of treatment. However, augmented AR signaling via both full length AR (AR-FL) and constitutively active AR splice variants, especially AR-V7, is associated with the recurrence of castration resistant prostate cancer (CRPC). Oxidative stress also plays a crucial role in anti-androgen resistance and CRPC outgrowth. We examined whether a triterpenoid antioxidant drug, Bardoxolone-methyl, known as CDDO-Me or RTA 402, can decrease AR-FL and AR-V7 expression in PC cells. Nanomolar (nM) concentrations of CDDO-Me rapidly downregulated AR-FL in LNCaP and C4-2B cells, and both AR-FL and AR-V7 in CWR22Rv1 (22Rv1) cells. The AR-suppressive effect of CDDO-Me was evident at both the mRNA and protein levels. Mechanistically, acute exposure (2 h) to CDDO-Me increased and long-term exposure (24 h) decreased reactive oxygen species (ROS) levels in cells. This was concomitant with an increase in the anti-oxidant transcription factor, Nrf2. The anti-oxidant N-acetyl cysteine (NAC) could overcome this AR-suppressive effect of CDDO-Me. Co-exposure of PC cells to CDDO-Me enhanced the efficacy of a clinically approved anti-androgen, enzalutamide (ENZ), as evident by decreased cell-viability along with migration and colony forming ability of PC cells. Thus, CDDO-Me which is in several late-stage clinical trials, may be used as an adjunct to ADT in PC patients.

The Non-Bone-Related Role of RANK/RANKL Signaling in Cancer

RANK ligand (RANKL) is a member of the tumor necrosis factor alpha superfamily of cytokines. It is the only known ligand binding to a membrane receptor named receptor activator of nuclear factor-kappa B (RANK), thereby triggering recruitment of TNF receptor-associated factor (TRAF) adaptor proteins and activation of downstream pathways. RANK/RANKL signaling is controlled by a decoy receptor, osteoprotegerin (OPG), but also has additional more complex levels of regulation. It is crucial for the differentiation of bone-resorbing osteoclasts and is deregulated in disease processes such as osteoporosis and cancer bone metastasis. Cells expressing RANK and RANKL are commonly found in the tumor environment. In many tumor types, the RANK/RANKL pathway is overexpressed, and this is in most cases correlated with poor prognosis. RANK signaling plays an important role in the innate and adaptive immune response, generates regulatory T (Treg) cells, and increases the production of cytokines. It is also involved in chemo resistance in vitro. Recent evidence suggests that RANKL blockade improves the efficacy of anti-CTLA-4 antibodies against solid tumors and experimental metastasis. Therefore, there is increasing interest to use RANKL inhibition as an immunomodulatory strategy in an attempt to make immune-resistant tumor responsive to immune therapy.

Cholesterol metabolism plays a crucial role in the regulation of autophagy for cell differentiation of granular convoluted tubules in male mouse submandibular glands

It has been long appreciated that sex hormone receptors are expressed in various non-gonadal organs. However, it remains unclear how sex hormones regulate the morphogenesis of these non-gonadal organs. To address this issue, we used a male mouse model of androgen-dependent salivary gland morphogenesis. Mice with excessive cholesterol synthesis in the salivary glands exhibited defects in the maturation of granular convoluted tubules (GCTs), which is regulated through sex hormone-dependent cascades. We found that excessive cholesterol synthesis resulted in autophagy failure specifically in the duct cells of salivary glands, followed by the accumulation of NRF2, a transcription factor known as one of the specific substrates for autophagy. The accumulated NRF2 suppressed the expression of Foxa1, which forms a transcriptional complex with the androgen receptor to regulate target genes. Taken together, our results indicate that cholesterol metabolism plays a crucial role in GCT differentiation through autophagy.

Reactive oxygen species and cancer: A complex interaction

Elevated levels of Reactive Oxygen Species (ROS), increased antioxidant ability and the maintenance of redox homeostasis can cumulatively contribute to tumor progression and metastasis. The sources and the role of ROS in a heterogeneous tumor microenvironment can vary at different stages of tumor: initiation, development, and progression, thus making it a complex subject. In this review, we have summarized the sources of ROS generation in cancer cells, its role in the tumor microenvironment, the possible functions of ROS and its important scavenger systems in tumor progression with special emphasis on solid tumors.

Communication between mitochondria and other organelles: a brand-new perspective on mitochondria in cancer

Mitochondria are energy factories of cells and are important pivots for intracellular interactions with other organelles. They interact with the endoplasmic reticulum, peroxisomes, and nucleus through signal transduction, vesicle transport, and membrane contact sites to regulate energy metabolism, biosynthesis, immune response, and cell turnover. However, when the communication between organelles fails and the mitochondria are dysfunctional, it may induce tumorigenesis. In this review, we elaborate on how mitochondria interact with the endoplasmic reticulum, peroxisomes, and cell nuclei, as well as the relation between organelle communication and tumor development .

Distinct isoforms of Nrf1 diversely regulate different subsets of its cognate target genes

The single Nrf1 gene has capability to be differentially transcripted alongside with alternative mRNA-splicing and subsequent translation through different initiation signals so as to yield distinct lengths of polypeptide isoforms. Amongst them, three of the most representatives are Nrf1α, Nrf1β and Nrf1γ, but the putative specific contribution of each isoform to regulating ARE-driven target genes remains unknown. To address this, we have herein established three cell lines on the base of the Flp-In T-REx system, which are allowed for the tetracycline-inducibly stable expression of Nrf1α, Nrf1β and Nrf1γ. Consequently, the RNA-Sequencing results have demonstrated that a vast majority of differentially expressed genes (i.e. >90% DEGs detected) were dominantly up-regulated by Nrf1α and/or Nrf1β following induction by tetracycline. By contrast, the other DEGs regulated by Nrf1γ were far less than those regulated by Nrf1α/β (i.e. ~11% of Nrf1α and ~7% of Nrf1β). However, further transcriptomic analysis revealed that the tetracycline-induced expression of Nrf1γ significantly increased the percentage of down-regulated genes in total DEGs. These statistical data were further validated by quantitative real-time PCR. The experimental results indicate that distinct Nrf1 isoforms make diverse and even opposing contributions to regulating different subsets of target genes, such as those encoding 26S proteasomal subunits and others involved in various biological processes and functions. Collectively, Nrf1γ acts as a major dominant-negative inhibitor competitively against Nrf1α/β activity, such that a number of DEGs regulated by Nrf1α/β are counteracted by Nrf1γ.

RANK/RANKL signaling inhibition may improve the effectiveness of checkpoint blockade in cancer treatment

Binding between the receptor activator of nuclear factor-kB (RANK) and its ligand (RANKL) triggers recruitment of TNF receptor associated factor (TRAF) adaptor proteins and activation of downstream pathways. RANK/RANKL signaling is controlled by a decoy receptor called osteoprotegerin (OPG) which interacts with RANKL. Additional networks regulating RANK/RANKL signaling are active in a context specific manner. RANK/RANKL signaling is essential for the differentiation of bone-resorbing osteoclasts, and is deregulated in pathological processes such as postmenopausal osteoporosis or cancer induced bone destruction. Cells expressing RANK and RANKL are commonly found in the tumor microenvironment. The RANKL/RANK pathway is often overexpressed in tumors of the breast, prostate, endometrium, cervix, stomach, oesophagus and bladder, thyroid and correlated with poor prognosis. RANK signaling plays an important role in the innate and adaptive immune response as it generates regulatory T (Treg) cells and increases production of cytokines. RANK expression induces chemoresistance in vitro through the activation of multiple signal transduction pathways. RANKL blockade improves the efficacy of anti-CTLA-4 monoclonal antibodies against solid tumors and experimental metastases. As RANK inhibition enhances the immune response there is an increasing interest in combining it with immune therapy in an attempt to sensitize immune resistant tumors to immune therapies. Several studies are ongoing to assess this concept. The role of RANK/RANKL inhibition should be further pursued as an immunomodulatory strategy in combination with other treatment modalities.

Nrf1D Is the First Candidate Secretory Transcription Factor in the Blood Plasma, Its Precursor Existing as a Unique Redox-Sensitive Transmembrane CNC-bZIP Protein in Hemopoietic and Somatic Tissues

Among multiple distinct isoforms, Nrf1D is synthesized from a de novo translation of an alternatively-spliced transcript of Nrf1 mRNA, as accompanied by a naturally-occurring deletion of its stop codon-flanking 1466 nucleotides. This molecular event leads to the generation of a reading frameshift mutation, which results in a constitutive substitution of the intact Nrf1's C-terminal 72 amino acids (aa, covering the second half of the leucine zipper motif to C-terminal Neh3L domain) by an additional extended 80-aa stretch to generate a unique variant Nrf1D. The C-terminal extra 80-aa region of Nrf1D was herein identified to be folded into a redox-sensitive transmembrane domain, enabling it to be tightly integrated within the endoplasmic reticulum (ER) membranes. Notably, the salient feature of Nrf1D enables it to be distinguishable from prototypic Nrf1, such that Nrf1D is endowed with a lesser ability than wild-type Nrf1 to mediate target gene expression. Further evidence has also been presented revealing that both mRNA and protein levels of Nrf1D, together with other isoforms similar to those of Nrf1, were detected to varying extents in hemopoietic and somatic tissues. Surprisingly, we found the existence of Nrf1D-derived isoforms in blood plasma, implying that it is a candidate secretory transcription factor, albeit its precursor acts as an integral transmembrane-bound CNC-bZIP protein that entails dynamic topologies across membranes, before being unleashed from the ER to enter the blood.

Targeting Crosstalk between Nrf-2, NF-κB and Androgen Receptor Signaling in Prostate Cancer

Oxidative stress, inflammation and androgen receptor (AR) signaling play a pivotal role in the initiation, development and progression of prostate cancer (PCa). Numerous papers in the literature have documented the interconnection between oxidative stress and inflammation; and how antioxidants can combat the inflammation. It has been shown in the literature that both oxidative stress and inflammation regulate AR, the key receptor involved in the transition of PCa to castration resistant prostate cancer (CRPC). In this review, we discuss about the importance of targeting Nrf-2-antioxidant signaling, NF-κB inflammatory response and AR signaling in PCa. Finally, we discuss about the crosstalk between these three critical pathways as well as how the anti-inflammatory antioxidant phytochemicals like sulforaphane (SFN) and curcumin (CUR), which can also target AR, can be ideal candidates in the chemoprevention of PCa.

Genes and Pathways Regulated by Androgens in Human Neural Cells, Potential Candidates for the Male Excess in Autism Spectrum Disorder

BACKGROUND

Prenatal exposure to androgens during brain development in male individuals may participate to increase their susceptibility to develop neurodevelopmental disorders such as autism spectrum disorder (ASD) and intellectual disability. However, little is known about the action of androgens in human neural cells.

METHODS

We used human neural stem cells differentiated from embryonic stem cells to investigate targets of androgens.

RESULTS

RNA sequencing revealed that treatment with dihydrotestosterone (DHT) leads to subtle but significant changes in the expression of about 200 genes, encoding proteins of extracellular matrix or involved in signal transduction of growth factors (e.g., insulin/insulin growth factor 1). We showed that the most differentially expressed genes (DEGs), RGCC, RNF144B, NRCAM, TRIM22, FAM107A, IGFBP5, and LAMA2, are reproducibly regulated by different androgens in different genetic backgrounds. We showed, by overexpressing the androgen receptor in neuroblastoma cells SH-SY5Y or knocking it down in human neural stem cells, that this regulation involves the androgen receptor. A chromatin immunoprecipitation combined with direct sequencing analysis identified androgen receptor-bound sequences in nearly half of the DHT-DEGs and in numerous other genes. DHT-DEGs appear enriched in genes involved in ASD (ASXL3, NLGN4X, etc.), associated with ASD (NRCAM), or differentially expressed in patients with ASD (FAM107A, IGFBP5). Androgens increase human neural stem cell proliferation and survival in nutrient-deprived culture conditions, with no detectable effect on regulation of neurite outgrowth.

CONCLUSIONS

We characterized androgen action in neural progenitor cells, identifying DHT-DEGs that appear to be enriched in genes related to ASD. We also showed that androgens increase proliferation of neuronal precursors and protect them from death during their differentiation in nutrient-deprived conditions.

Identification of epigenetic modulators in human breast cancer by integrated analysis of DNA methylation and RNA-Seq data

Human tumors undergo massive changes in DNA methylation. Recent studies showed that site-specific methylation of CpG sites is determined by the DNA sequence context surrounding the CpG site, which alludes to a possible mechanism for site-specific aberrant DNA methylation in cancer through DNA-binding proteins. In this paper, DNA methylation data and RNA-Seq data of breast tumors and normal tissues in the database of The Cancer Genome Atlas (TCGA) were integrated with information of DNA motifs in seven databases to find DNA-binding proteins and their binding motifs that were involved in aberrant DNA methylation in breast cancer. A total of 42,850 differentially methylated regions (DMRs) that include 77,298 CpG sites were detected in breast cancer. One hundred eight DNA motifs were found to be enriched in DMRs, and 109 genes encoding proteins binding to these motifs were determined. Based on these motifs and genes, 63 methylation modulator genes were identified to regulate differentially methylated CpG sites in breast cancer. A network of these 63 modulator genes and 645 transcription factors was constructed, and 20 network modules were determined. A number of pathways and gene sets related to breast cancer were found to be enriched in these network modules. The 63 methylation modulator genes identified may play an important role in aberrant methylation of CpG sites in breast cancer. They may help to understand site-specific dysregulation of DNA methylation and provide epigenetic markers for breast cancer.

Anti-Inflammatory and Antioxidant Effects of Kelong-Capsule on Testosterone-Induced Benign Prostatic Hyperplasia in Rats

Benign prostatic hyperplasia (BPH) is a common disease in the current ageing male population. This research aims to study the effects of Kelong-Capsules (KLC) on testosterone-induced BPH. Thirty rats were randomly divided into normal group, model group, and three treatment groups. Three treatment groups were given KLC (3.6 g/kg), KLC (7.2 g/kg), and finasteride (0.9 mg/kg), respectively, for 28 days after establishing the animal model. The BPH rat models were evaluated by Traditional Chinese Medicine (TCM) symptoms and prostate index (PI). Results indicated that three treatment groups all alleviated the pathological changes of prostate and kidney at different levels. Compared with the model group, the PI of the groups treated with KLC (7.2 g/kg) and finasteride decreased significantly. The expressions of NF-E2 related factor 2 (Nrf-2) and quinine oxidoreductase (NQO1) in the group treated with KLC (3.6 g/kg) increased markedly (p < 0.01). The cyclooxygenase-2 (COX-2) protein expression of the group treated with KLC (7.2 g/kg) was increased (p < 0.01). In conclusion, KLC could obviously inhibit the growth of prostate, and KLC (3.6 g/kg) could promote the expressions of Nrf2 and NQO1.

Nuclear transcription factor Nrf2 suppresses prostate cancer cells growth and migration through upregulating ferroportin

VTo investigate the effect of nuclear transcription factor Nrf2 on the transcription of Ferroportin (FPN) in prostate cancer cells, and the regulation mechanisms of FPN on cell viability, migration and apoptosis of prostate cancer cells.Empty vectors, pEGFPC1-Nrf2, pEGFPC1-FPN, Si-FPN and Si-Nrf2 were transfected into prostate cancer cell line PC3. The expression of mRNA and protein were measured by real time-PCR (RT-PCR) and western blot. Cell viability, migration, cycle and apoptosis were tested by CCK-8 assay, wound healing and flow cytometry, respectively. The interaction between FPN and Nrf2 was confirmed by chromatin immunoprecipitation (CHIP) assay.The viability, migration and mitosis of PC3 cells could be repressed by over-expressed FPN, with decreased intracellular ferritin. The CHIP assay demonstrated that Nrf2 is one transcription factor of FPN and promotes its transcription. With the increase of Nrf2 in PC3 cells, the viability, migration ability and concentration of ferritin were suppressed, while the apoptosis rate was increased. The above effects were counteracted by down-regulating FPN.FPN could inhibit the prostate cancer cell viability, migration and mitosis, which is also related to a decrease of intracellular ferritin content. In conclusion, Nrf2 suppresses prostate cancer cells viability, migration, and mitosis through upregulating FPN.

Gene polymorphisms in antioxidant enzymes correlate with the efficacy of androgen-deprivation therapy for prostate cancer with implications of oxidative stress

Background

Oxidative stress mitigated by antioxidant enzymes is thought to be involved in the progression to castration-resistant prostate cancer (CRPC) during androgen-deprivation therapy (ADT). This study investigated the association between genetic variations in antioxidant enzymes and the efficacy of ADT as well as its biological background.

Patients and methods

The non-synonymous or promoter-locating polymorphisms of antioxidant enzymes were examined as well as the time to CRPC progression and overall survival in 104 and 92 patients treated with ADT for metastatic and non-metastatic prostate cancer, respectively. In addition, intracellular reactive oxygen species and expression levels of antioxidant enzymes were examined in castration-resistant and enzalutamide-resistant cells.

Results

In metastatic prostate cancer, the AG/GG allele in GSTM3 rs7483 and CT/TT allele in CAT rs564250 were associated with a significantly lower risk of progression to CRPC and all-cause death compared with homozygotes of the major AA allele (hazard ratio [HR]; [95% confidence interval (CI)], 0.55 [0.34-0.86], P = 0.0086) and CC allele (HR; [95% CI], 0.48 [0.24-0.88], P = 0.016), respectively. On multivariate analyses, only GSTM3 rs7483 was associated with significant progression risk (AG/GG versus AA; HR; [95% CI], 0.45 [0.25-0.79], P = 0.0047) even after Bonferroni adjustment. In non-metastatic prostate cancer, the AG/GG allele in GSTM3 rs7483 was associated with a significantly lower risk of progression to CRPC (HR; [95% CI], 0.35 [0.10-0.93], P = 0.034) and all-cause death (HR; [95% CI], 0.26 [0.041-0.96], P = 0.043) compared with the AA allele. Intracellular reactive oxygen species levels were increased, accompanied with augmented GSTM3 expression in both castration-resistant and enzalutamide-resistant cells.

Conclusions

Differential activity of antioxidant enzymes caused by the polymorphism in GSTM3 may contribute to resistance to hormonal therapy through oxidative stress. The GSTM3 rs7483 polymorphism may be a promising biomarker for prostate cancer patients treated with ADT.

Thioredoxin system-mediated regulation of mutant Kras associated pancreatic neoplasia and cancer

Peroxiredoxin-1 (Prdx1), a member of the thioredoxin (Txn) system, is overexpressed and correlates with poor prognosis in pancreatic cancer patients and can suppress Kras signaling through redox-mediated inhibition of ERK and AKT in lung and breast cancer. Its redox function is maintained by Txn and sulfiredoxin (Srxn), and its tumor promoting functions are activated by post-translational modification. We studied the role of the Txn system in pancreatic neoplasia and cancer by determining how it regulates the phosphorylation of Kras effectors and by determining its association with patient survival. We found that elevated Prdx1 nuclear localization significantly correlated with better patient survival. Our data also demonstrate that the expression of the Txn system is dysregulated, with elevated Prdx1 expression and significantly decreased Txn and Srxn expression in pancreatic lesions of targeted mutant Kras mouse models. This correlated with distinct differences in the interconversion of Prdx1 oligomers that affect its ability to regulate ERK and AKT phosphorylation. Our data also suggest that Prdx1 post-translational modification and oligomerization suppress Prdx1 mediated redox regulation of ERK phosphorylation. We observed distinct differences in Txn expression and in the ability of pTyr-Prdx1 to bind to pERK in a PanIN model of pancreatic neoplasia as compared to an IPMN model, indicating a distinct difference in the function of post-translationally modified Prdx1 in cells with less Txn expression. Modified Txn system function and post-translational regulation may therefore play a significant role in pancreatic tumorigenesis by altering Kras effector phosphorylation and inhibiting the tumor suppressive redox functions of Prdx1.

Multimodal actions of the phytochemical sulforaphane suppress both AR and AR-V7 in 22Rv1 cells: Advocating a potent pharmaceutical combination against castration-resistant prostate cancer

Prostate cancer (PCa) cells expressing full-length androgen receptor (AR-FL) are susceptible to androgen deprivation therapy (ADT). However, outgrowth of castration-resistant prostate cancer (CRPC) can occur due to the expression of constitutively active (ligand-independent) AR splice variants, particularly AR-V7. We previously demonstrated that sulforaphane (SFN), an isothiocyanate phytochemical, can decrease AR-FL levels in the PCa cell lines, LNCaP and C4-2B. Here, we examined the efficacy of SFN in targeting both AR-FL and AR-V7 in the CRPC cell line, CWR22Rv1 (22Rv1). MTT cell viability, wound-heal assay, and colony forming unit (CFU) measurements revealed that 22Rv1 cells are resistant to the anti-androgen, enzalutamide (ENZ). However, co-exposure to SFN sensitized these cells to the potent anticancer effects of ENZ (P<0.05). Immunoblot analyses showed that SFN (5–20 µM) rapidly decreases both AR-FL and AR-V7 levels, and immunofluorescence microscopy (IFM) depicted decreased AR in both cytoplasm and nucleus with SFN treatment. SFN increased both ubiquitination and proteasomal activity in 22Rv1 cells. Studies using a protein synthesis inhibitor (cycloheximide) or a proteasomal inhibitor (MG132) indicated that SFN increases both ubiquitin-mediated aggregation and subsequent proteasomal-degradation of AR proteins. Previous studies reported that SFN inhibits the chaperone activity of heat-shock protein 90 (Hsp90) and induces the nuclear factor erythroid-2-like 2 (Nrf2) transcription factor. Therefore, we investigated whether the Hsp90 inhibitor, ganetespib (G) or the Nrf2 activator, bardoxolone methyl (BM) can similarly suppress AR levels in 22Rv1 cells. Low doses of G and BM, alone or in combination, decreased both AR-FL and AR-V7 levels, and combined exposure to G+BM sensitized 22Rv1 cells to ENZ. Therefore, adjunct treatment with the phytochemical SFN or a safe pharmaceutical combination of G+BM may be effective against CRPC cells, especially those expressing AR-V7.

Identification of novel prostate cancer drivers using RegNetDriver: a framework for integration of genetic and epigenetic alterations with tissue-specific regulatory network

We report a novel computational method, RegNetDriver, to identify tumorigenic drivers using the combined effects of coding and non-coding single nucleotide variants, structural variants, and DNA methylation changes in the DNase I hypersensitivity based regulatory network. Integration of multi-omics data from 521 prostate tumor samples indicated a stronger regulatory impact of structural variants, as they affect more transcription factor hubs in the tissue-specific network. Moreover, crosstalk between transcription factor hub expression modulated by structural variants and methylation levels likely leads to the differential expression of target genes. We report known prostate tumor regulatory drivers and nominate novel transcription factors (ERF, CREB3L1, and POU2F2), which are supported by functional validation.

DNA methylation-based chromatin compartments and ChIP-seq profiles reveal transcriptional drivers of prostate carcinogenesis

BACKGROUND

Profiles of DNA methylation of many tissues relevant in human disease have been obtained from microarrays and are publicly available. These can be used to generate maps of chromatin compartmentalization, demarcating open and closed chromatin across the genome. Additionally, large sets of genome-wide transcription factor binding profiles have been made available thanks to ChIP-seq technology.

METHODS

We have identified genomic regions with altered chromatin compartmentalization in prostate adenocarcinoma tissue relative to normal prostate tissue, using DNA methylation microarray data from The Cancer Genome Atlas. DNA binding profiles from the Encyclopedia of DNA Elements (ENCODE) ChIP-seq studies have been systematically screened to find transcription factors with inferred DNA binding sites located in discordantly open/closed chromatin in malignant tissue (compared with non-cancer control tissue). We have combined this with tests for corresponding up-/downregulation of the transcription factors' putative target genes to obtain an integrated measure of cancer-specific regulatory activity to identify likely transcriptional drivers of prostate cancer.

RESULTS

Generally, we find that the degree to which transcription factors preferentially bind regions of chromatin that become more accessible during prostate carcinogenesis is significantly associated to the level of systematic upregulation of their targets, at the level of gene expression. Our approach has yielded 11 transcription factors that show strong cancer-specific transcriptional activation of targets, including the novel candidates KAT2A and TRIM28, alongside established drivers of prostate cancer MYC, ETS1, GABP and YY1.

CONCLUSIONS

This approach to integrated epigenetic and transcriptional profiling using publicly available data represents a cheap and powerful technique for identifying potential drivers of human disease. In our application to prostate adenocarcinoma data, the fact that well-known drivers are amongst the top candidates suggests that the discovery of novel candidate drivers may unlock pathways to future medicines. Data download instructions and code to reproduce this work are available at GitHub under 'edcurry/PRAD-compartments'.

Glyoxalase 2 drives tumorigenesis in human prostate cells in a mechanism involving androgen receptor and p53-p21 axis

Glyoxalase 2 (Glo2), a metabolic enzyme, is overexpressed in some human cancers which suggests this enzyme may play a role in human tumorigenesis. In prostate cancer (PCa), the role of Glo2 has been scarcely investigated and there are no studies addressing a causative involvement of this protein in this neoplasia. Here, we examined the immunohistochemical profile of Glo2 in human PCa and benign adjacent tissues and investigated Glo2 involvement in PCa development in human prostate cell lines. PCa and matched adjacent normal tissues were obtained from paraffin sections of primary PCa from 20 patients who had undergone radical prostatectomy. Histopathological diagnosis was confirmed for each sample. Glo2 expression analysis was performed by immunohistochemistry in prostate tissues, and by qRT-PCR and immunoblotting in prostate cell lines. The causative and mechanistic role of Glo2 in prostate tumorigenesis was demonstrated by Glo2 ectopic expression/silencing and employing specific activators/inhibitors. Our results showed that Glo2 was selectively expressed in PCa but not in the luminal compartment of the adjacent benign epithelium consistently in all the examined 20 cases. Glo2 expression in PCa was dependent on androgen receptor (AR) and was aimed at stimulating cell proliferation and eluding apoptosis through a mechanism involving the p53-p21 axis. Glo2 was intensely expressed in the basal cells of benign glands but was not involved in PCa genesis. Our results demonstrate for the first time that Glo2 drives prostate tumorigenesis and suggest that it may represent a novel adjuvant marker in the pathological diagnosis of early PCa.

Complex molecular changes induced by chronic progestogens exposure in roach, Rutilus rutilus

In our previous study, we measured 0.23-13.67ng/L progestogens (progesterone, drospirenone, levonorgestrel) in natural waters in the catchment area of the largest shallow lake of Central Europe, Lake Balaton. Progestogen contaminations act as potent steroids with mixed progestagenic, androgenic and mild estrogenic effects that is why our aim was to investigate the morphological and molecular effects of mixture of progesterone, drospirenone, and levonorgestrel in environmentally relevant (10ng/L) and higher (50 and 500ng/L) exposure concentrations in common roach, Rutilus rutilus. Steroids (e.g. progestogens) and the protein deglycase DJ-1 chaperon molecule aim the same target molecules in cells, therefore, we hypothesized that a relationship may exist between progestogens and DJ-1. Furthermore, our other aim was to follow the changes of signal molecules of different biological function due to progestogen treatment in serum and brain. Adult roaches were exposed to 10, 50 and 500ng/L of mixture of progestogen for 42 days and their somatic indices (brain-somatic, liver-somatic, gonadosomatic and kidney-somatic) were measured. Vitellogenin (VTG) expression (estrogen effect) or inhibition (androgen effect) in fish is a widely used biomarker so we measured its changes in liver by ELISA. To determine the quantity and to map the spatial distribution of DJ-1 chaperon protein the brain and liver tissues were analyzed by ELISA and immunohistochemistry. Furthermore, we also studied molecular alterations: a) in the serum by measuring cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglyceride concentrations and b) in brain homogenate using a cell stress array kit (26 protein). The somatic index of liver and kidney significantly in all the treated groups, whereas the gonadosomatic index of 500ng/L treated group showed significant decrease compared to control animals. VTG level increased significantly in 500ng/L progestogen treated group. Since the concentration of DJ-1 significantly increased in brain and liver in all progestogen treatment groups, the DJ-1 protein could be able to a more sensitive marker than VTG. Serum LDL and cholesterol levels of exposed fish were significantly decreased. DJ-1 was mediated through the stimulation of the expression of LDL-receptor which facilitates reuptake subsequently. In summary, our observations unfolded new data about molecular alterations induced by the combined action of environmental progestogens. In addition, the DJ-1 chaperon protein as a possible biomarker helped to trace the abiotic chemical environmental contaminations, like progestogens in the freshwater ecosystems.

Molecular and cellular basis for the unique functioning of Nrf1, an indispensable transcription factor for maintaining cell homoeostasis and organ integrity

The consensuscis-regulatory AP-1 (activator protein-1)-like AREs (antioxidant-response elements) and/or EpREs (electrophile-response elements) allow for differential recruitment of Nrf1 [NF-E2 (nuclear factor-erythroid 2)-related factor 1], Nrf2 and Nrf3, together with each of their heterodimeric partners (e.g. sMaf, c-Jun, JunD or c-Fos), to regulate different sets of cognate genes. Among them, NF-E2 p45 and Nrf3 are subject to tissue-specific expression in haemopoietic and placental cell lineages respectively. By contrast, Nrf1 and Nrf2 are two important transcription factors expressed ubiquitously in various vertebrate tissues and hence may elicit putative combinational or competitive functions. Nevertheless, they have de facto distinct biological activities because knockout of their genes in mice leads to distinguishable phenotypes. Of note, Nrf2 is dispensable during development and growth, albeit it is accepted as a master regulator of antioxidant, detoxification and cytoprotective genes against cellular stress. Relative to the water-soluble Nrf2, less attention has hitherto been drawn to the membrane-bound Nrf1, even though it has been shown to be indispensable for embryonic development and organ integrity. The biological discrepancy between Nrf1 and Nrf2 is determined by differences in both their primary structures and topovectorial subcellular locations, in which they are subjected to distinct post-translational processing so as to mediate differential expression of ARE-driven cytoprotective genes. In the present review, we focus on the molecular and cellular basis for Nrf1 and its isoforms, which together exert its essential functions for maintaining cellular homoeostasis, normal organ development and growth during life processes. Conversely, dysfunction of Nrf1 results in spontaneous development of non-alcoholic steatohepatitis, hepatoma, diabetes and neurodegenerative diseases in animal models.

Sulforaphane increases the efficacy of anti-androgens by rapidly decreasing androgen receptor levels in prostate cancer cells

Prostate cancer (PCa) cells utilize androgen for their growth. Hence, androgen deprivation therapy (ADT) using anti-androgens, e.g. bicalutamide (BIC) and enzalutamide (ENZ), is a mainstay of treatment. However, the outgrowth of castration resistant PCa (CRPC) cells remains a significant problem. These CRPC cells express androgen receptor (AR) and utilize the intratumoral androgen towards their continued growth and invasion. Sulforaphane (SFN), a naturally occurring isothiocyanate found in cruciferous vegetables, can decrease AR protein levels. In the present study, we tested the combined efficacy of anti-androgens and SFN in suppressing PCa cell growth, motility and clonogenic ability. Both androgen-dependent (LNCaP) and androgen-independent (C4-2B) cells were used to monitor the effects of BIC and ENZ, alone and in combination with SFN. Co-exposure to SFN significantly (p<0.005) enhanced the anti-proliferative effects of anti-androgens and downregulated expression of the AR-responsive gene, prostate specific antigen (PSA) (p<0.05). Exposure to SFN decreased AR protein levels in a time- and dose-dependent manner with almost no AR detected at 24 h with 15 µM SFN (p<0.005). This rapid and potent AR suppression by SFN occurred by both AR protein degradation, as suggested by cycloheximide (CHX) co-exposure studies, and by suppression of AR gene expression, as evident from quantitative RT-PCR experiments. Pre-exposure to SFN also reduced R1881-stimulated nuclear localization of AR, and combined treatment with SFN and anti-androgens abrogated the mitogenic effects of this AR-agonist (p<0.005). Wound-healing assays revealed that co-exposure to SFN and anti-androgens can significantly (p<0.005) reduce PCa cell migration. In addition, long-term exposures (14 days) to much lower concentrations of these agents, SFN (0.2 µM), BIC (1 µM) and/or ENZ (0.4 µM) significantly (p<0.005) decreased the number of colony forming units (CFUs). These findings clearly suggest that SFN may be used as a promising adjunct agent to augment the efficacy of anti-androgens against aggressive PCa cells.

Consensus reference gene(s) for gene expression studies in human cancers: end of the tunnel visible?

BACKGROUND

Gene expression studies are increasingly used to provide valuable information on the diagnosis and prognosis of human cancers. Also, for in vitro and in vivo experimental cancer models gene expression studies are widely used. The complex algorithms of differential gene expression analyses require normalization of data against a reference or normalizer gene, or a set of such genes. For this purpose, mostly invariant housekeeping genes are used. Unfortunately, however, there are no consensus (housekeeping) genes that serve as reference or normalizer for different human cancers. In fact, scientists have employed a wide range of reference genes across different types of cancer for normalization of gene expression data. As a consequence, comparisons of these data and/or data harmonizations are difficult to perform and challenging. In addition, an inadequate choice for a reference gene may obscure genuine changes and/or result in erroneous gene expression data comparisons.

METHODS

In our effort to highlight the importance of selecting the most appropriate reference gene(s), we have screened the literature for gene expression studies published since the turn of the century on thirteen of the most prevalent human cancers worldwide.

CONCLUSIONS

Based on the analysis of the data at hand, we firstly recommend that in each study the suitability of candidate reference gene(s) should carefully be evaluated in order to yield reliable differential gene expression data. Secondly, we recommend that a combination of PPIA and either GAPDH, ACTB, HPRT and TBP, or appropriate combinations of two or three of these genes, should be employed in future studies, to ensure that results from different studies on different human cancers can be harmonized. This approach will ultimately increase the depth of our understanding of gene expression signatures across human cancers.

Respiratory protease/antiprotease balance determines susceptibility to viral infection and can be modified by nutritional antioxidants

The respiratory epithelium functions as a central orchestrator to initiate and organize responses to inhaled stimuli. Proteases and antiproteases are secreted from the respiratory epithelium and are involved in respiratory homeostasis. Modifications to the protease/antiprotease balance can lead to the development of lung diseases such as emphysema or chronic obstructive pulmonary disease. Furthermore, altered protease/antiprotease balance, in favor for increased protease activity, is associated with increased susceptibility to respiratory viral infections such as influenza virus. However, nutritional antioxidants induce antiprotease expression/secretion and decrease protease expression/activity, to protect against viral infection. As such, this review will elucidate the impact of this balance in the context of respiratory viral infection and lung disease, to further highlight the role epithelial cell-derived proteases and antiproteases contribute to respiratory immune function. Furthermore, this review will offer the use of nutritional antioxidants as possible therapeutics to boost respiratory mucosal responses and/or protect against infection.