Long noncoding RNA TUG1 regulates prostate cancer cell proliferation, invasion and migration via the Nrf2 signaling axis

Nrf2 in human cancers: biological significance and therapeutic potential

The nuclear factor-erythroid 2-related factor 2 (Nrf2) is able to control the redox balance in the cells responding to oxidative damage and other stress signals. The Nrf2 upregulation can elevate the levels of antioxidant enzymes to support against damage and death. In spite of protective function of Nrf2 in the physiological conditions, the stimulation of Nrf2 in the cancer has been in favour of tumorigenesis. Since the dysregulation of molecular pathways and mutations/deletions are common in tumors, Nrf2 can be a promising therapeutic target. The Nrf2 overexpression can prevent cell death in tumor and by increasing the survival rate of cancer cells, ensures the carcinogenesis. Moreover, the induction of Nrf2 can promote the invasion and metastasis of tumor cells. The Nrf2 upregulation stimulates EMT to increase cancer metastasis. Furthermore, regarding the protective function of Nrf2, its stimulation triggers chemoresistance. The natural products can regulate Nrf2 in the cancer therapy and reverse drug resistance. Moreover, nanostructures can specifically target Nrf2 signaling in cancer therapy. The current review discusses the potential function of Nrf2 in the proliferation, metastasis and drug resistance. Then, the capacity of natural products and nanostructures for suppressing Nrf2-mediated cancer progression is discussed.

Increased ferroptosis in leukocytes from preeclamptic women involving the long non-coding taurine upregulated gene 1 (TUG1)

BACKGROUND

Ferroptosis plays a key role in placental development and physiology, and abnormal ferroptosis has been implicated in trophoblast injury leading to preeclampsia (PE). We hypothesize that leukocytes isolated from PE exhibit increased ferroptosis and that extracellular vesicles contain long non-coding (lnc) RNA/mRNAs that modulate oxidative stress and iron toxicity in vascular endothelial cells.

METHODS

We measured the expression of key regulators of ferroptosis in leukocytes and extracellular vesicles as well as circulating biomarkers of iron homeostasis and oxidative stress in plasma from women with/without PE at different timepoints during pregnancy. For markers that were dysregulated, we assessed their temporal correlation with established markers of disease activity and marker of endothelial activation. For markers dysregulated in early pregnancy, we assessed their ability to predict the development of PE.

RESULTS

We found decreased lncRNA/mRNAs in leukocytes, but not extracellular vesicles, in PE that may modulate oxidative stress and iron toxicity. This decrease in anti-ferroptotic markers does not appear to be related to maternal disease activity or plasma oxidative stress status but rather to attenuated anti-inflammatory expression in these cells. Circulating ferritin was elevated in PE, supporting the hypothesis that PE represents a disbalance in iron homeostasis. Low lncRNA taurine upregulated gene 1 RNA levels in leukocytes at 22-24 weeks were strongly associated with the development of PE.

CONCLUSIONS

Our findings suggest that maternal leukocytes in PE show decreased anti-ferroptotic activity that correlates with anti-inflammatory expression. Moreover, some of these changes in ferroptotic activity appear to precede the development of PE.

Long non-coding RNA NMRAL2P promotes glycolysis and reduces ROS in head and neck tumors by interacting with the ENO1 protein and promoting GPX2 transcription

Background

Metabolic reprogramming is a key marker in the occurrence and development of tumors. This process generates more reactive oxygen species (ROS), promoting the development of oxidative stress. To prevent ROS from harming tumor cells, tumor cells can increase the production of reducing agents to counteract excessive ROS. NMRAL2P has been shown to promote the production of reductive mRNA and plays an important role in the process of oxidative stress.

Methods

In this study, the clinical data and RNA sequencing of head and neck tumors were obtained from The Cancer Genome Atlas data set. The long non-coding RNA (LncRNA) related to oxidative stress were then identified using differential and correlation analyses. The differential expression and prognosis of the identified lncRNA were then verified using samples from the library of the Second Hospital of Hebei Medical University. Only NMRAL2P was substantially expressed in cancer tissues and predicted a poor prognosis. The tumor-promoting impact of NMRAL2P was then confirmed using in vitro functional assays. The data set was then split into high- and low-expression subgroups based on the median gene expression of NMRAL2P to obtain the mRNA that had a large difference between the two groups, and examine the mechanism of NMRAL2P on GPX2 using quantitative real-time PCR, RNA binding protein immunoprecipitation assay, and chromatin immunoprecipitation. Mass spectrometry was used to identify NMRAL2P-binding proteins and western blotting was used to investigate probable mechanisms.

Results

The lncRNA NMRAL2P is associated with oxidative stress in head and neck tumors. In vitro functional assays showed that the gene has a cancer-promoting effect, increasing lactic acid and superoxide dismutase production, and reducing the production of ROS and malondialdehyde. NMRAL2P promotes the transcription of GPX2 by binding to transcription factor Nrf2. The gene also inhibits the degradation of ENO1, a crucial enzyme in glycolysis, by binding to protein ENO1.

Conclusions

This study shows that NMRAL2P can promote glycolysis and reduce the harm to tumor cells caused by ROS. The gene can also be used as a possible target for the treatment of head and neck tumors.

miR-29a-5p modulates ferroptosis by targeting ferritin heavy chain FTH1 in prostate cancer

Ferroptosis is a kind of regulatory necrosis caused by phospholipid iron-dependent peroxidation. MiRNAs are known to play key roles in diverse biological functions. However, the molecular basis of miRNA-mediated ferroptosis in prostate cancer has not been fully stated. Here, with TCGA prostate cancer miRNA-seq data, we utilized Multivariate Cox regression analysis to prioritize potential miRNA and validated it in vitro and in vivo. We identified miR-29a-5p by TCGA prostate cancer miRNA-seq dataset. And we confirmed the expression of miR-29a-5p in prostate cancer cell lines. MiR-29a-5p knockdown reduced proliferation in PC-3 and LNCaP cells while increased Fe²⁺ and malondialdehyde (MDA) levels, the opposite phenomenon was observed with miR-29a-5p overexpression. Luciferase reporter assay showed an interaction between miR-29a-5p and Nrf2 downstream gene FTH1, subsequent rescue experiments also indirectly proved their direct effect. Finally, suppression of miR-29a-5p effectively inhibited tumor growth in vivo. These findings proved that the important role of miR-29a-5p in prostate cancer ferroptosis.

Long Non-Coding RNA-GDA-1 Promotes Keratinocyte Proliferation and Psoriasis Inflammation by Regulating the STAT3/NF-κB Signaling Pathway via Forkhead Box M1

Psoriasis is a chronic inflammatory skin disease associated with multiple comorbidities and complex pathogenesis. Long non-coding RNAs (lncRNAs) play an important regulatory role in many diseases, including psoriasis. In this study, We aimed to investigate the role and mechanism of lncRNA GDA-1 (GDA) in M5-treated psoriatic keratinocytes. GDA expression was significantly upregulated in psoriatic tissues and M5-treated keratinocytes. By silencing and overexpressing GDA in NHEKs and Ker-CT cells, we showed that GDA regulated proliferation and cell cycle and increased secretion of interleukin-1β (IL-1β), IL-6, and chemokine ligands 2 and 20 (CCL2 and CCL20). RNA sequencing after GDA silencing led to the identification of a close regulatory relationship between GDA and Forkhead Box M1 (FOXM1). GDA significantly influenced FOXM1 expression at both mRNA and protein levels and activated STAT3/NF-κB signaling pathways. STAT3 and NF-κB inhibition abrogated GDA effects on keratinocyte proliferation and inflammation. In conclusion, our study is the first to report that Lnc-GDA-1 distinctly regulates FOXM1 expression and mediates proliferation and inflammation of psoriatic keratinocytes through the STAT3/NF-κB signaling pathway, which may be a potent target for psoriasis treatment.

Interplay between Non-Coding RNAs and NRF2 in Different Cancers: Spotlight on MicroRNAs and Long Non-Coding RNAs

Cancer is a multifactorial disease, and a wealth of information has enabled basic and clinical researchers to develop a better conceptual knowledge of the highly heterogeneous nature of cancer. Deregulations of spatio-temporally controlled transduction pathways play a central role in cancer progression. NRF2-driven signaling has engrossed significant attention because of its fundamentally unique features to dualistically regulate cancer progression. Context-dependent diametrically opposed roles of NRF2-induced signaling are exciting. More importantly, non-coding RNA (ncRNA) mediated regulation of NRF2 and interplay between NRF2 and ncRNAs have added new layers of complexity to already intricate nature of NRF2 signaling. There is a gradual enrichment in the existing pool of knowledge related to interplay between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in different cancers. However, surprisingly, there are no clues about interplay between circular RNAs and NRF2 in various cancers. Therefore, future studies must converge on the functional characterization of additional important lncRNAs and circular RNAs, which regulated NRF2-driven signaling or, conversely, NRF2 transcriptionally controlled their expression to regulate various stages of cancer. SIGNIFICANCE STATEMENT: Recently, many researchers have focused on the NRF2-driven signaling in cancer progression. Excitingly, discovery of non-coding RNAs has added new layers of intricacy to the already complicated nature of KEAP1/NRF2 signaling in different cancers. These interactions are shaping the NRF2-driven signaling landscape, and better knowledge of these pathways will be advantageous in pharmacological modulation of non-coding RNA-mediated NRF2 signaling in various cancers.

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.

mRNA-Modified FUS/NRF2 Signalling Inhibits Ferroptosis and Promotes Prostate Cancer Growth

Objective. Regarding the imperfect mechanism of occurrence and development of prostate adenocarcinoma (PRAD), this study investigated mRNA-modified FUS/NRF2 signalling to inhibit ferroptosis and promote prostate adenocarcinoma growth. Methods. Bioinformatics analysis was used to obtain the expression of FUS and its mRNA modification in PRAD. The expression of FUS in prostate cells (CRPC) and the level of m6A methylation modification, ferroptosis (P53 and GPX4), apoptosis (Caspase3), ferroptosis (P53 and GPX4), and apoptosis (Caspase3) in CRPC after ferroptosis inducer Erastin, ferroptosis inhibitor, and FUS knockdown were detected. Autophagy (LC3B), oxidative stress (GSH and ROS), and expression of NRF2/HO-1 pathway are indicators. Results. FUS was highly expressed in PRAD and phenomenally reduced the survival rate of patients. After knocking down FUS, the level of m6A methylation was significantly reduced, and the expressions of ferroptosis markers P53 and GPX4 were phenomenally reduced, while the levels of apoptosis and autophagy markers Caspase3 and LC3B remained unchanged. Upregulated and NRF2/HO-1 pathway indicators were upregulated. It shows that m6A methylation modification is reduced when FUS is the low expression, inhibits the expression of P53 and GPX4, downregulates GSH, upregulates ROS, activates the NRF2/HO-1 pathway, and promotes ferroptosis to inhibit the occurrence of RPAD. Conclusions. The increase of m6A methylation modification can increase the expression of FUS, thereby promoting the expression of P53 and GPX4, upregulating GSH, downregulating ROS, inhibiting the NRF2/HO-1 pathway, inhibiting ferroptosis, and promoting the growth of PRAD.

Non-coding RNAs associated with autophagy and their regulatory role in cancer therapeutics

Cancer widely affects the world's health population and ranks second leading cause of death globally. Because of poor prognosis of various types of cancer such as sarcoma, lymphoma, adenomas etc., their high recurrence and metastasis rate and low early diagnosis rate have become concern lately. Role of autophagy in cancer progression is being studied since long. Autophagy is cell's self-degradative mechanism towards stress and has role in degradation of the cytoplasmic macromolecules which has potential to damage other cytosolic molecules. Autophagy can promote as well as inhibit tumorigenesis depending upon the associated protein combinations in cancer cells. Recent studies have shown that non-coding RNAs (ncRNAs) do not code for protein but play essential role in modulation of gene expression. At transcriptional level, different ncRNAs like lncRNAs, miRNAs and circRNAs directly or indirectly affect different stages of autophagy like autophagy-dependent and non-apoptotic cell death in cancer cells. This review focuses on the involvement of ncRNAs in autophagy and the modulation of several cancer signal transduction pathways in cancers such as lung, breast, prostate, pancreatic, thyroid, and kidney cancer.

TUG1 long non-coding RNA enlists the USF1 transcription factor to overexpress ROMO1 leading to hepatocellular carcinoma growth and metastasis

Hepatocellular carcinoma (HCC) is a prevalent and highly aggressive cancer. Long non‐coding RNAs (lncRNAs) are recognized as potential molecular targets for HCC and are currently under increased research focus. Here, we investigate the regulatory processes underlying the axis of the lncRNA taurine upregulated gene 1 (TUG1), Upstream Transcription Factor 1 (USF1), and reactive oxygen species modulator 1 (ROMO1) in the propagation and metastasis of HCC cells. Distribution of lncRNA TUG1 was found to be prominent in HCC cell cytoplasm and nuclei. LncRNA TUG1 conscripted the USF1 transcription factor to enhance the promoter function of ROMO1. Enlisting the USF1 transcription factor to increase ROMO1 expression following upregulation of TUG1 lncRNA enhanced HCC Huh7 cell proliferation, motility, and metastasis. Rapid tumor proliferation in nude mice provided in vivo verification. The importance of the lncRNA TUG1/USF1/ROMO1 complex as a target for HCC therapy is a key result of this investigation which is exemplified by its role in regulating the proliferation, motility, and metastasis of HCC cells.

Comprehensive Pan-Cancer Analysis of the Prognostic and Immunological Roles of the METTL3/lncRNA-SNHG1/miRNA-140-3p/UBE2C Axis

Growing evidence has demonstrated that UBE2C plays a critical role in cancer progression, but there is no study focusing on the prognosis, upstream regulation mechanism, and immunological roles of UBE2C across diverse tumor types. In this study, we found that UBE2C was elevated in this human pan-cancer analysis, and high expression of UBE2C was correlated with poor prognosis. In addition, UBE2C expression was markedly associated with tumor mutation burden (TMB), microsatellite instability (MSI), immune cell infiltration, and diverse drug sensitivities. Finally, we showed that the METTL3/SNHG1/miRNA-140-3p axis could potentially regulate UBE2C expression. N(6)-Methyladenosine (m6A) modifications improved the stability of methylated SNHG1 transcripts by decreasing the rate of RNA degradation, which lead to upregulation of SNHG1 in non-small cell lung cancer (NSCLC). In vitro functional experiments showed that SNHG1, as a competing endogenous RNA, sponges miR-140-3p to increase UBE2C expression in NSCLC cell lines. Our study elucidates the clinical importance and regulatory mechanism of the METTL3/SNHG1/miRNA-140-3p/UBE2C axis in NSCLC and provides a prognostic indicator, as well as a promising therapeutic target for patients with NSCLC.

Inhibition of Kelch-like epichlorohydrin-related protein 1 promotes the progression and drug resistance of lung adenocarcinoma

Background

Lung cancer is a common malignant carcinoma of respiratory system with high morbidity and mortality. Kelch-like epichlorohydrin-related protein 1 (Keap1), a member of the BTB-Kelch protein family, has been reported as an important molecule in several cancers. However, its potential role in tumor is still controversial. Here we aim to clarify the effect of Keap1 on the biological characteristics and chemotherapy resistance in lung adenocarcinoma (LUAD).

Methods

Immunohistochemistry was conducted to compare Keap1 expression in lung adenocarcinoma tissues and matched non-cancerous tissues, and the correlation between Keap1 expression and clinicopathological features was analyzed. Subsequently, the stable A549 and H1299 cell lines with Keap1 knockdown or overexpression were constructed using lentivirus. The roles of Keap1 on the cell proliferation, migration, invasion and drug resistance were investigated by colony formation assay, cell proliferation assay, wound scratch test, transwell invasion assay and drug sensitivity assay, respectively.

Results

Keap1 was lowly expressed in tumor tissues compared to matched non-cancerous tissues, and its expression was correlated with TNM stage and lymph node metastasis. Early stage (I) tumors without lymph node metastasis had higher levels of Keap1 expression compared with late-stage tumors (II, III) with the presence of lymphatic metastasis. Colony formation assays showed that Keap1 knockdown promoted the proliferation of A549 and H1299 cells, and the cell growth curves further confirmed this feature. In contrast, wound scratch and transwell invasion experiments showed that Keap1 overexpression inhibited cell migration and invasive malignancy. The IC50 for cisplatin and paclitaxel were significantly increased by Keap1 knockdown in A549 and H1299 cell lines.

Conclusion

Keap1 knockdown promotes tumor cell growth, proliferation, invasion, metastasis and chemotherapy resistance in LUAD. It may be a potential tumor marker to guide the staging and treatment of lung cancer.

Role of long non-coding RNAs on the regulation of Nrf2 in chronic diseases

Studies have identified dysregulated long non-coding RNA (lncRNA) in several diseases at transcriptional, translational, and post-translational levels. Although our mechanistic knowledge on the regulation of lncRNAs is still limited, one of the mechanisms of action attributed is binding and regulating transcription factors, thus controlling gene expression and protein function. One such transcription factor is nuclear factor erythroid 2-related factor 2 (Nrf2), which plays a critical biological role in maintaining cellular homeostasis at multiple levels in physiological and pathophysiological conditions. The levels of Nrf2 were found to be down-regulated in many chronic diseases, signifying that Nrf2 can be a key therapeutic target. Few lncRNAs like lncRNA ROR, ENSMUST00000125413, lncRNA ODRUL, Nrf2-lncRNA have been associated with the Nrf2 signaling pathway in response to various stimuli, including stress. This review discusses the regulation of Nrf2 in different responses and the potential role of specific lncRNA in modulating its transcriptional activities. This review further helps to enhance our knowledge on the regulatory role of the critical antioxidant transcription factor, Nrf2.

NRF2 Regulation by Noncoding RNAs in Cancers: The Present Knowledge and the Way Forward

Simple Summary

The NRF2 pathway represents one of the most intriguing pathways that promotes chemo- and radioresistance of neoplastic cells. Increasing findings suggest that the NRF2 signaling can be modulated by multiple epigenetic factors such as noncoding RNAs, which influence a large number of oncogenic mechanisms, both at transcriptional and at post-transcriptional levels. As a consequence, the identification and characterization of specific noncoding RNAs as biomarkers related to oxidative stress may help to clarify the relationship between them and NRF2 signaling in the tumor context, in terms of positive and negative modulation, also referring to their intersection with other NRF2 crosstalking pathways. In this review, we summarize the recent updates on NRF2 network regulation by noncoding RNAs in tumors, thus paving the way toward the potential translational role of these small RNAs as key tumor biomarkers of neoplastic processes.

Abstract

Nuclear factor erythroid 2-related factor 2 (NRF2) is the key transcription factor triggered by oxidative stress that moves in cells of the antioxidant response element (ARE)-antioxidant gene network against reactive oxygen species (ROS) cellular damage. In tumors, the NRF2 pathway represents one of the most intriguing pathways that promotes chemo- and radioresistance of neoplastic cells and its activity is regulated by genetic and epigenetic mechanisms; some of these being poorly investigated in cancer. The noncoding RNA (ncRNA) network is governed by microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) and modulates a variety of cellular mechanisms linked to cancer onset and progression, both at transcriptional and post-transcriptional levels. In recent years, the scientific findings about the effects of ncRNA landscape variations on NRF2 machines are rapidly increasing and need to be continuously updated. Here, we review the latest knowledge about the link between NRF2 and ncRNA networks in cancer, thus focusing on their potential translational significance as key tumor biomarkers.

Regulatory effects of noncoding RNAs on the interplay of oxidative stress and autophagy in cancer malignancy and therapy

Noncoding RNAs (ncRNAs) regulation of various diseases including cancer has been extensively studied. Reactive oxidative species (ROS) elevated by oxidative stress are associated with cancer progression and drug resistance, while autophagy serves as an ROS scavenger in cancer cells. However, the regulatory effects of ncRNAs on autophagy and ROS in various cancer cells remains complex. Here, we explore how currently investigated ncRNAs, mainly miRNAs and lncRNAs, are involved in ROS production through modulating antioxidant genes. The regulatory effects of miRNAs and lncRNAs on autophagy-related (ATG) proteins to control autophagy activity in cancer cells are discussed. Moreover, differential expression of ncRNAs in tumor and normal tissues of cancer patients are further analyzed using The Cancer Genome Atlas (TCGA) database. This review hypothesizes links between ATG genes- or antioxidant genes-modulated ncRNAs and ROS production, which might result in tumorigenesis, malignancy, and cancer recurrence. A better understanding of the regulation of ROS and autophagy by ncRNAs might advance the use of ncRNAs as diagnostic and prognostic markers as well as therapeutic targets in cancer therapy.

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.