microRNAs Tune Oxidative Stress in Cancer Therapeutic Tolerance and Resistance

Autophagy-modulating biomembrane nanostructures: A robust anticancer weapon by modulating the inner and outer cancer environment

Recently, biomembrane nanostructures, such as liposomes, cell membrane-coated nanostructures, and exosomes, have demonstrated promising anticancer therapeutic effects. These nanostructures possess remarkable biocompatibility, multifunctionality, and low toxicity. However, their therapeutic efficacy is impeded by chemoresistance and radiotherapy resistance, which are closely associated with autophagy. Modulating autophagy could enhance the therapeutic sensitivity and effectiveness of these biomembrane nanostructures by influencing the immune system and the cancer microenvironment. For instance, autophagy can regulate the immunogenic cell death of cancer cells, antigen presentation of dendritic cells, and macrophage polarization, thereby activating the inflammatory response in the cancer microenvironment. Furthermore, combining autophagy-regulating drugs or genes with biomembrane nanostructures can exploit the targeting and long-term circulation properties of these nanostructures, leading to increased drug accumulation in cancer cells. This review explores the role of autophagy in carcinogenesis, cancer progression, metastasis, cancer immune responses, and resistance to treatment. Additionally, it highlights recent research advancements in the synergistic anticancer effects achieved through autophagy regulation by biomembrane nanostructures. The review also discusses the prospects and challenges associated with the future clinical translation of these innovative treatment strategies. In summary, these findings provide valuable insights into autophagy, autophagy-modulating biomembrane-based nanostructures, and the underlying molecular mechanisms, thereby facilitating the development of promising cancer therapeutics.

The Potential Role of Epigenetic Modifications on Different Facets in the Periodontal Pathogenesis

Periodontitis is a chronic inflammatory disease that affects the supporting structures of teeth. In the literature, the association between the pathogenicity of bacteria and environmental factors in this regard have been extensively examined. In the present study, we will shed light on the potential role that epigenetic change can play on different facets of its process, more particularly the modifications concerning the genes involved in inflammation, defense, and immune systems. Since the 1960s, the role of genetic variants in the onset and severity of periodontal disease has been widely demonstrated. These make some people more susceptible to developing it than others. It has been documented that the wide variation in its frequency for various racial and ethnic populations is due primarily to the complex interplay among genetic factors with those affecting the environment and the demography. In molecular biology, epigenetic modifications are defined as any change in the promoter for the CpG islands, in the structure of the histone protein, as well as post-translational regulation by microRNAs (miRNAs), being known to contribute to the alteration in gene expression for complex multifactorial diseases such as periodontitis. The key role of epigenetic modification is to understand the mechanism involved in the gene-environment interaction, and the development of periodontitis is now the subject of more and more studies that attempt to identify which factors are stimulating it, but also affect the reduced response to therapy.

A novel gene signature related to oxidative stress predicts the prognosis in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is considered to be related to the worse prognosis, which might in part be attributed to the early recurrence and metastasis, compared with other type of kidney cancer. Oxidative stress refers to an imbalance between production of oxidants and antioxidant defense. Accumulative studies have indicated that oxidative stress genes contribute to the tumor invasion, metastasis and drug sensitivity. However, the biological functions of oxidative stress genes in ccRCC remain largely unknown. In this study, we identified 1,399 oxidative stress genes from GeneCards with a relevance score ≥7. Data for analysis were accessed from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) database, and were utilized as training set and validation set respectively. Univariate Cox analysis, least absolute shrinkage and selection operator (LASSO) Cox regression and multivariate Cox were employed to construct a prognostic signature in ccRCC. Finally, a prognostic signature including four different oxidative stress genes was constructed from 1,399 genes, and its predictive performance was verified through Kaplan-Meier survival analysis and the receiver operating characteristic (ROC) curve. Interestingly, we found that there was significant correlation between the expression of oxidative stress genes and the immune infiltration and the sensitivity of tumor cells to chemotherapeutics. Moreover, the highest hazard ratio gene urocortin (UCN) was chosen for further study; some necessary vitro experiments proved that the UCN could promote the ability of ccRCC proliferation and migration and contribute to the degree of oxidative stress. In conclusion, it was promising to predict the prognosis of ccRCC through the four oxidative stress genes signature. UCN played oncogenic roles in ccRCC by influencing proliferation and oxidative stress pathway, which was expected to be the novel therapeutic target for ccRCC.

A macrocyclic molecule with multiple antioxidative activities protects the lens from oxidative damage

Growing evidence links oxidative stress to the development of a cataract and other diseases of the eye. Treatments for lens-derived diseases are still elusive outside of the standard surgical interventions, which still carry risks today. Therefore, a potential drug molecule OHPy2N2 was explored for the ability to target multiple components of oxidative stress in the lens to prevent cataract formation. Several pathways were identified. Here we show that the OHPy2N2 molecule activates innate catalytic mechanisms in primary lens epithelial cells to prevent damage induced by oxidative stress. This protection was linked to the upregulation of Nuclear factor erythroid-2-related factor 2 and downstream antioxidant enzyme for glutathione-dependent glutaredoxins, based on Western Blot methods. The anti-ferroptotic potential was established by showing that OHPy2N2 increases levels of glutathione peroxidase, decreases lipid peroxidation, and readily binds iron (II) and (III). The bioenergetics pathway, which has been shown to be negatively impacted in many diseases involving oxidative stress, was also enhanced as evidence by increased levels of Adenosine triphosphate product when the lens epithelial cells were co-incubated with OHPy2N2. Lastly, OHPy2N2 was also found to prevent oxidative stress-induced lens opacity in an ex vivo organ culture model. Overall, these results show that there are multiple pathways that the OHPy2N2 has the ability to impact to promote natural mechanisms within cells to protect against chronic oxidative stress in the eye.

Oxidative Stress Biomarkers in the Diagnosis and Prognosis

Oxidative stress describes the state of a cell where there is an imbalance between free radical formation and antioxidants due to either excess formation of reactive oxygen species (ROS) or inadequate antioxidant defence. It is very well known that oxidative stress plays an important role in the pathophysiology of various diseases through impaired intracellular redox homeostasis. To evaluate and imply the excess production of ROS, various biomarkers are used and suggested, yet it is also known that there is a lack of standardization and validation for these methods. It is almost very difficult to measure ROS directly because of their short half-life, yet it is still possible with a suitable technique. The most frequently used biomarkers are represented by oxidized macromolecules such as lipids, proteins, and nucleic acids, which are modified via ROS, and also the amounts or activities of antioxidant molecules and enzymes, respectively. There are also various genetic biomarkers measuring the susceptibility of modification due to oxidative stress. However, the preferred biomarker would be dependent on the aim of the study and the clinical relevance.

Cyanidin-3-O-glucoside inhibits the β-catenin/MGMT pathway by upregulating miR-214-5p to reverse chemotherapy resistance in glioma cells

Overcoming resistance to alkylating agents has important clinical significance in glioma. Cyanidin-3-O-glucoside (C3G) has a tumor-suppressive effect on tumor cells. However, whether it plays a role in temozolomide resistance in glioma is still unclear. We constructed a TMZ-resistant LN-18/TR glioma cell line, observed the effect of C3G on TMZ resistance in this cell line, and explored the role of miR-214-5p in chemoresistance. Results showed that β-catenin and MGMT were significantly upregulated in LN-18/TR cells. C3G upregulated miR-214-5p and enhanced the cytotoxic effect of temozolomide on LN-18/TR cells. Contrarily, C3G downregulated β-catenin and MGMT. Moreover, the miR-214-5p mimic downregulated β-catenin and MGMT in LN-18/TR cells, whereas the miR-214-5p inhibitor had the opposite effect; the miR-214-5p inhibitor significantly blocked the C3G-induced downregulation of β-catenin and MGMT. C3G or the miR-214-5p mimic enhanced temozolomide-induced apoptosis in LN-18/TR cells, whereas the miR-214-5p inhibitor blocked this effect. Furthermore, C3G or miR-214-5p agomir combined with TMZ significantly inhibited the growth of LN-18/TR tumors. Collectively, our research discovered the potential signaling mechanism associated with C3G-mediated suppression of TMZ resistance in LN-18/TR cells through miR-214-5p, which can facilitate the treatment of MGMT-induced resistance in glioma cells.

MicroRNA-21 guide and passenger strand regulation of adenylosuccinate lyase-mediated purine metabolism promotes transition to an EGFR-TKI-tolerant persister state

In EGFR-mutant lung cancer, drug-tolerant persister cells (DTPCs) show prolonged survival when receiving EGFR tyrosine kinase inhibitor (TKI) treatments. They are a likely source of drug resistance, but little is known about how these cells tolerate drugs. Ribonucleic acids (RNAs) molecules control cell growth and stress responses. Nucleic acid metabolism provides metabolites, such as purines, supporting RNA synthesis and downstream functions. Recently, noncoding RNAs (ncRNAs), such as microRNAs (miRNAs), have received attention due to their capacity to repress gene expression via inhibitory binding to downstream messenger RNAs (mRNAs). Here, our study links miRNA expression to purine metabolism and drug tolerance. MiR-21-5p (guide strand) is a commonly upregulated miRNA in disease states, including cancer and drug resistance. However, the expression and function of miR-21-3p (passenger strand) are not well understood. We found that upregulation of miR-21-5p and miR-21-3p tune purine metabolism leading to increased drug tolerance. Metabolomics data demonstrated that purine metabolism was the top pathway in the DTPCs compared with the parental cells. The changes in purine metabolites in the DTPCs were partially rescued by targeting miR-21. Analysis of protein levels in the DTPCs showed that reduced expression of adenylosuccinate lyase (ADSL) was reversed after the miR-21 knockdown. ADSL is an essential enzyme in the de novo purine biosynthesis pathway by converting succino-5-aminoimidazole-4-carboxamide riboside (succino-AICAR or SAICAR) to AICAR (or acadesine) as well as adenylosuccinate to adenosine monophosphate (AMP). In the DTPCs, miR-21-5p and miR-21-3p repress ADSL expression. The levels of top decreased metabolite in the DTPCs, AICAR was reversed when miR-21 was blocked. AICAR induced oxidative stress, evidenced by increased reactive oxygen species (ROS) and reduced expression of nuclear factor erythroid-2-related factor 2 (NRF2). Concurrently, miR-21 knockdown induced ROS generation. Therapeutically, a combination of AICAR and osimertinib increased ROS levels and decreased osimertinib-induced NRF2 expression. In a MIR21 knockout mouse model, MIR21 loss-of-function led to increased purine metabolites but reduced ROS scavenging capacity in lung tissues in physiological conditions. Our data has established a link between ncRNAs, purine metabolism, and the redox imbalance pathway. This discovery will increase knowledge of the complexity of the regulatory RNA network and potentially enable novel therapeutic options for drug-resistant patients.

MicroRNA-27a promotes tumorigenesis in tongue squamous cell carcinoma by enhancing proliferation, migration and suppressing apoptosis

BACKGROUND

Tongue squamous cell carcinoma (TSCC) is a major subtype of head and neck squamous cell carcinoma (HNSCC), which is an intractable cancer with a poor prognosis. Studies have shown that microRNAs (miRNAs) play an important role in TSCC biology. However, the expression and functions of miRNAs in TSCC remain unclear.

METHODS

The non-coding RNA profiles of TSCC were downloaded from the GEO database. WGCNA (Weighted gene co-expression network analysis) and differential expression miRNA (DE-miRNA) analyses were employed to identify key candidate miRNAs. miRNA expression was detected using RT-qPCR analysis. The target genes of key miRNAs were predicted. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed to explore the potential functions and pathways of key miRNA. miRNA inhibitor was transfected to detect the function of miRNA. The effect of miRNA deregulation on TSCC cell proliferation and apoptosis was investigated using MTS, Annexin V-FITC/PI double staining, and flow cytometry assays.

RESULTS

miR-27a was a key miRNA in TSCC, which was significantly up-regulated in both Cal-27 cells and malignant tissues from the TSCC patients. In addition, functional analysis showed that miR-27a was involved in the regulation of the MAPK, ERBB, and Jak-STAT signaling pathways. Moreover, RHOA and PRKACA were potential target genes of miR-27a, suggesting them as possible mediators of the tumor-promoting effect of miR-27a. Moreover, downregulation of miR-27a inhibited cell proliferation and facilitated cell apoptosis in Cal-27 cells.

CONCLUSION

Our findings strongly suggest that miR-27a could promote the tumorigenesis and development of TSCC, which makes it a potential new diagnostic marker and therapeutic target for TSCC.

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.

miR129-1 regulates protein phosphatase 1D protein expression under hypoxic conditions in non-small cell lung cancer cells harboring a TP53 mutation

Protein phosphatase 1D (PPM1D), which functions as an oncogene, is a known target of the tumor suppressor p53 and is involved in p53-regulated genomic surveillance mechanisms. PPM1D dephosphorylates both p53 and its ubiquitin ligase mouse double minute 2 homolog, as well as the RNA-binding protein (RBM)38, which turns RBM38 from an inducer to inhibitor of TP53 translation. In addition, RBM38 induces PPM1D translation. Hence, the PPM1D-RBM38-p53 axis is important in maintaining genomic integrity and is often altered during tumorigenesis. TP53, which encodes p53, is deleted or mutated in >50% of cancer types, including lung cancer. Mutant p53 has been revealed to complex with hypoxia-inducible factor 1α (HIF1α) and upregulate transcription of pro-metastatic genes. However, the mechanism underlying the action of the PPM1D-RBM38-p53 axis in the context of mutant p53 under normoxic and hypoxic conditions is yet to be elucidated. In the present study, using non-small cell lung cancer (NSCLC) cell lines harboring wild-type (A549 cells) or hot-spot mutant (NCI-H1770 and R249WΔ-TP53-A549 cells) TP53, it was demonstrated that in cells harboring mutant p53, RBM38 was not the primary regulator of PPM1D translation under hypoxic conditions. Knockdown of RBM38 in TP53 mutant cells did not affect the PPM1D protein expression under hypoxic conditions. Instead, in NCI-H1770 cells maintained under normoxic conditions, PPM1D was revealed as a target of micro RNA (miR)-129-1-3p, a known tumor suppressor in lung cancer. Hypoxia resulted in the downregulation of miR-129-1-3p expression, and thus, in the downregulation of PPM1D messenger RNA (mRNA) translation. In NCI-H1770 cells grown under hypoxic conditions, the transient transfection of miR-129-1-3p mimic, and not control mimic, repressed the expression of a reporter containing wild-type, but not miR-129-1-3p binding mutant, of the PPM1D 3'-untranslated region (UTR). Analysis of NSCLC cell lines from the Broad Institute Cancer Cell Encyclopedia and patients with NSCLC from The Cancer Genome Atlas dataset revealed significant co-occurrence of PPM1D/RBM38 and PPM1D/HIF1A mutations. However, there was no significant difference in the overall survival of patients with NSCLC with or without genomic alterations in TP53, RBM38, PPM1D and HIF1A. In summary, the current study demonstrated hypoxia-dependent miR-129-1-3p-mediated regulation of PPM1D protein expression in NSCLC cell line harboring mutant TP53.

MicroRNAs in the regulation of cellular redox status and its implications in myocardial ischemia-reperfusion injury

MicroRNAs (miRNAs) are small RNAs that do not encode for proteins and play key roles in the regulation of gene expression. miRNAs are involved in a comprehensive range of biological processes such as cell cycle control, apoptosis, and several developmental and physiological processes. Oxidative stress can affect the expression levels of multiple miRNAs and, conversely, miRNAs may regulate the expression of redox sensors, alter critical components of the cellular antioxidants, interact with the proteasome, and affect DNA repair systems. The number of publications identifying redox-sensitive miRNAs has increased significantly over the last few years, and some miRNA targets such as Nrf2, SIRT1 and NF-κB have been identified. The complex interplay between miRNAs and ROS is discussed together with their role in myocardial ischemia-reperfusion injury and the potential use of circulating miRNAs as biomarkers of myocardial infarction. Detailed knowledge of redox-sensitive miRNAs is needed to be able to effectively use individual compounds or sets of miRNA-modulating compounds to improve the health-related outcomes associated with different diseases.

Targeting Oxidative Stress for Disease Prevention and Therapy: Where Do We Stand, and Where Do We Go from Here

Oxidative stress (OxS) is one of the main processes related to aging and a common denominator of many different chronic/degenerative diseases (e.g., cardiovascular and neurodegenerative conditions and cancer). Thus, its potential modulation by supplementation/pharmacological therapy caused a lot of interest. However, these expectations have been mitigated by the obtainment of controversial results (beneficial, null, or adverse effects) following antioxidant interventions. Here, we discuss the current understanding of OxS assessment in health and disease, challenges and the potential of its evaluation in clinical practice, and available and future development for supplementation and pharmacologic strategies targeting OxS.

Non-Coding RNAs in Lung Tumor Initiation and Progression

Lung cancer is one of the deadliest forms of cancer affecting society today. Non-coding RNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), through the transcriptional, post-transcriptional, and epigenetic changes they impose, have been found to be dysregulated to affect lung cancer tumorigenesis and metastasis. This review will briefly summarize hallmarks involved in lung cancer initiation and progression. For initiation, these hallmarks include tumor initiating cells, immortalization, activation of oncogenes and inactivation of tumor suppressors. Hallmarks involved in lung cancer progression include metastasis and drug tolerance and resistance. The targeting of these hallmarks with non-coding RNAs can affect vital metabolic and cell signaling pathways, which as a result can potentially have a role in cancerous and pathological processes. By further understanding non-coding RNAs, researchers can work towards diagnoses and treatments to improve early detection and clinical response.