MicroRNA-Mediated Regulation of HMGB1 in Human Hepatocellular Carcinoma

hsa_circ_0001508 as a new gene that may promote breast cancer progression via the miR‑505‑3p/HMGB1, VGLL3 axis

Breast cancer (BC) is a malignant tumor, that damages the physical health of female patients. It is crucial to develop new treatment strategies for BC, as this disease significantly affects the quality of life of women in both developing and developed countries, despite the existence of effective treatment options to reduce mortality. Recently, several researchers have been studying circular RNAs (circRNAs) in BC due to their stability and sponge function. In the present study, a new circRNA, hsa_circ_0001508, was discovered using Gene Chip's prediction. This gene is important because it is novel in BC. However, due to financial constraints, the study was designed as a pilot study for future research. The present study included several common biomedical experimental techniques, such as reverse transcription-quantitative PCR, flow cytometry, cell counting, cell invasion, wound healing assay and western blotting. It also involves the use of DNA microarray (gene chip) and prediction of microRNA and mRNA interactions using bioinformatics tools such as TargetScan. The findings revealed that hsa_circ_0001508 exhibits carcinogenic properties that facilitate the progression of BC. Furthermore, potential binding sites were identified as crucial areas for future investigation.

Recent Advances in RNA Interference-Based Therapy for Hepatocellular Carcinoma: Emphasis on siRNA

Even though RNA treatments were first proposed as a way to change aberrant signaling in cancer, research in this field is currently ongoing. The term "RNAi" refers to the use of several RNAi technologies, including ribozymes, riboswitches, Aptamers, small interfering RNA (siRNA), antisense oligonucleotides (ASOs), and CRISPR/Cas9 technology. The siRNA therapy has already achieved a remarkable feat by revolutionizing the treatment arena of cancers. Unlike small molecules and antibodies, which need administration every three months or even every two years, RNAi may be given every quarter to attain therapeutic results. In order to overcome complex challenges, delivering siRNAs to the targeted tissues and cells effectively and safely and improving the effectiveness of siRNAs in terms of their action, stability, specificity, and potential adverse consequences are required. In this context, the three primary techniques of siRNA therapies for hepatocellular carcinoma (HCC) are accomplished for inhibiting angiogenesis, decreasing cell proliferation, and promoting apoptosis, are discussed in this review. We also deliberate targeting issues, immunogenic reactions to siRNA therapy, and the difficulties with their intrinsic chemistry and transportation.

Suppression of microRNA-320 Induces Cerebral Protection Against Ischemia/Reperfusion Injury by Targeting HMGB1/NF-kappaB Axis

MicroRNAs have been shown to potentially function in cerebral ischemia/reperfusion (IR) injury. This study aimed to examine the expression of microRNA-320 (miR-320) in cerebral IR injury and its involvement in cerebral mitochondrial function, oxidative stress, and inflammatory responses by targeting the HMGB1/NF-kappaB axis. Sprague-Dawley rats were subjected to middle cerebral artery occlusion to simulate cerebral IR injury. The cerebral expression of miR-320 was assessed using qRT-PCR. Neurological function, cerebral infarct volume, mitochondrial function, oxidative stress, and inflammatory cytokines were evaluated using relevant methods, including staining, fluorometry, and ELISA. HMGB1 expression was analyzed through Western blotting. The levels of miR-320, HMGB1, neurological deficits, and cerebral infarction were significantly higher after IR induction. Intracerebral overexpression of miR-320 resulted in substantial neurological deficits, increased infarct volume, elevated levels of 8-isoprostane, NF-kappaBp65, TNF-alpha, IL-1beta, ICAM-1, VCAM-1, and HMGB1 expression. It also promoted the loss of mitochondrial membrane potential and ROS levels while reducing MnSOD and GSH levels. Downregulation of miR-320 and inhibition of HMGB1 activity significantly reversed the outcomes of cerebral IR injury. MiR-320 plays a negative role in regulating cerebral inflammatory/oxidative reactions induced by IR injury by enhancing HMGB1 activity and modulating mitochondrial function.

TSLP and HMGB1: Inflammatory Targets and Potential Biomarkers for Precision Medicine in Asthma and COPD

The airway epithelium, through pattern recognition receptors expressed transmembrane or intracellularly, acts as a first line of defense for the lungs against many environmental triggers. It is involved in the release of alarmin cytokines, which are important mediators of inflammation, with receptors widely expressed in structural cells as well as innate and adaptive immune cells. Knowledge of the role of epithelial cells in orchestrating the immune response and mediating the clearance of invading pathogens and dead/damaged cells to facilitate resolution of inflammation is necessary to understand how, in many chronic lung diseases, there is a persistent inflammatory response that becomes the basis of underlying pathogenesis. This review will focus on the role of pulmonary epithelial cells and of airway epithelial cell alarmins, in particular thymic stromal lymphopoietin (TSLP) and high mobility group box 1 (HMGB1), as key mediators in driving the inflammation of chronic lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD), evaluating the similarities and differences. Moreover, emerging concepts regarding the therapeutic role of molecules that act on airway epithelial cell alarmins will be explored for a precision medicine approach in the context of pulmonary diseases, thus allowing the use of these molecules as possible predictive biomarkers of clinical and biological response.

miRNA dysregulation in traumatic brain injury and epilepsy: a systematic review to identify putative biomarkers for post-traumatic epilepsy

Traumatic brain injury (TBI) leads to post-traumatic epilepsy (PTE); hence, both TBI and PTE share various similar molecular mechanisms. MicroRNA (miRNA) is a small noncoding RNA that acts as a gene-silencing molecule. Notably, the dysregulation of miRNAs in various neurological diseases, including TBI and epilepsy, has been reported in several studies. However, studies on commonly dysregulated miRNAs and the regulation of shared pathways in both TBI and epilepsy that can identify potential biomarkers of PTE are still lacking. This systematic review covers the peer-review publications of TBI and database studies of epilepsy-dysregulated miRNAs of clinical studies. For TBI, 290 research articles were identified after screening, and 12 provided data for dysregulated miRNAs in humans. The compiled data suggest that 85 and 222 miRNAs are consecutively dysregulated in TBI and epilepsy. In both, 10 miRNAs were found to be commonly dysregulated, implying that they are potentially dysregulated miRNAs for PTE. Furthermore, the targets and involvement of each putative miRNA in different pathways were identified and evaluated. Additionally, clusters of predicted miRNAs were analyzed. Each miRNA's regulatory role was linked with apoptosis, inflammation, and cell cycle regulation pathways. Hence, these findings provide insight for future diagnostic biomarkers.

Hypoxia-Regulated Tumor-Derived Exosomes and Tumor Progression: A Focus on Immune Evasion

Tumor cells express a high quantity of exosomes packaged with unique cargos under hypoxia, an important characteristic feature in solid tumors. These hypoxic tumor-derived exosomes are, crucially, involved in the interaction of cancer cells with their microenvironment, facilitating not only immune evasion, but increased cell growth and survival, enhanced angiogenesis, epithelial–mesenchymal transition (EMT), therapeutic resistance, autophagy, pre-metastasis, and metastasis. This paper explores the tumor microenvironment (TME) remodeling effects of hypoxic tumor-derived exosome towards facilitating the tumor progression process, particularly, the modulatory role of these factors on tumor cell immune evasion through suppression of immune cells, expression of surface recognition molecules, and secretion of antitumor soluble factor. Tumor-expressed exosomes educate immune effector cells, including macrophages, monocytes, T cells, natural killer (NK) cells, dendritic cells (DCs), γδ T lymphocytes, regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), mast cells, and B cells, within the hypoxic TME through the release of factors that regulate their recruitment, phenotype, and function. Thus, both hypoxia and tumor-derived exosomes modulate immune cells, growth factors, cytokines, receptor molecules, and other soluble factors, which, together, collaborate to form the immune-suppressive milieu of the tumor environment. Exploring the contribution of exosomal cargos, such as RNAs and proteins, as indispensable players in the cross-talk within the hypoxic tumor microenvironmental provides a potential target for antitumor immunity or subverting immune evasion and enhancing tumor therapies.

High Mobility Group Box 1: Biological Functions and Relevance in Oxidative Stress Related Chronic Diseases

In the early 1970s, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and named high-mobility group (HMG) proteins. High-mobility group box 1 (HMGB1) is the most studied HMG protein that detects and coordinates cellular stress response. The biological function of HMGB1 depends on its subcellular localization and expression. It plays a critical role in the nucleus and cytoplasm as DNA chaperone, chromosome gatekeeper, autophagy maintainer, and protector from apoptotic cell death. HMGB1 also functions as an extracellular alarmin acting as a damage-associated molecular pattern molecule (DAMP). Recent findings describe HMGB1 as a sophisticated signal of danger, with a pleiotropic function, which is useful as a clinical biomarker for several disorders. HMGB1 has emerged as a mediator in acute and chronic inflammation. Furthermore, HMGB1 targeting can induce beneficial effects on oxidative stress related diseases. This review focus on HMGB1 redox status, localization, mechanisms of release, binding with receptors, and its activities in different oxidative stress-related chronic diseases. Since a growing number of reports show the key role of HMGB1 in socially relevant pathological conditions, to our knowledge, for the first time, here we analyze the scientific literature, evaluating the number of publications focusing on HMGB1 in humans and animal models, per year, from 2006 to 2021 and the number of records published, yearly, per disease and category (studies on humans and animal models).

HMGB1: An overview of its roles in the pathogenesis of liver disease

High-mobility group box 1 (HMGB1) is an abundant architectural chromosomal protein that has multiple biologic functions: gene transcription, DNA replication, DNA-damage repair, and cell signaling for inflammation. HMGB1 can be released passively by necrotic cells or secreted actively by activated immune cells into the extracellular milieu after injury. Extracellular HMGB1 acts as a damage-associated molecular pattern to initiate the innate inflammatory response to infection and injury by communicating with neighboring cells through binding to specific cell-surface receptors, including Toll-like receptors (TLRs) and the receptor for advanced glycation end products (RAGE). Numerous studies have suggested HMGB1 to act as a key protein mediating the pathogenesis of chronic and acute liver diseases, including nonalcoholic fatty liver disease, hepatocellular carcinoma, and hepatic ischemia/reperfusion injury. Here, we provide a detailed review that focuses on the role of HMGB1 and HMGB1-mediated inflammatory signaling pathways in the pathogenesis of liver diseases.

Angiotensin II promotes EMT of hepatocellular carcinoma cells through high mobility group protein B1 mediated by E4F1

To screen for specific transcription factors (TFs) that induce expression of the HMGB1 promoter in response to stimulation by Ang-II. A HMGB1 overexpressing vector and small interfering (si)RNA were constructed and used to transfect the three HCC cell lines used in scratched monolayer wound healing and Transwell assays. Chromatin immunoprecipitation (ChIP) assays were used to confirm the relationship between a specific TF and the HMGB1 promoter. Invasion and migration by HMGB1 overexpressing HCC cells after treatment with Ang-II were significantly increased compared to negative controls (NC); E-cadherin was down-regulated while vimentin was up-regulated. However, compared with NC, invasion and migration by HMGB1 siRNA HCC cells stimulated by Ang-II were not altered; the expression of E-cadherin and vimentin was also unaltered. Nineteen TFs were predicted by Promoter 2.0 Prediction Server and TFsitescan. Real-time qPCR was used to evaluate TF expression levels. E4F1 was the only TF abnormally elevated in all three HCC cell lines when stimulated by Ang-II. WB and ChIP assays revealed high expression of E4F1 compared to other TFs in cells stimulated by Ang-II. E4F1 is activated by Ang-II and binds to the HMGB1 promoter region to promote HMGB1 expression; it then enhances Ang-II to induce HCC cell invasion and migration, and EMT.

HMGB1 as a therapeutic target in disease

High-mobility group box 1 (HMGB1) was initially recognized as a ubiquitous nuclear protein involved in maintaining the nucleosome integrity and facilitating gene transcription. HMGB1 has since been reevaluated to be a prototypical damage-associated molecular pattern (DAMP) protein, and together with its exogenous counterpart, pathogen-associated molecular pattern (PAMP), completes the body's alarmin system against disturbances in homeostasis. HMGB1 can be released into the extracellular matrix (ECM) by either granulocytes or necrotic cells to serve as a chemotaxis/cytokine during infection, endotoxemia, hypoxia, ischemia-reperfusion events, and cancer. Different isoforms of HMGB1 present with distinctive physiological functions in ECM-fully-reduced HMGB1 (all thiol) acts as the initial damage signal to recruit circulating myeloid cells, disulfide HMGB1 behaves as a cytokine to activate macrophages and neutrophils, and both signals are turned off when HMGB1 is terminally oxidized into the final sulfonate form. Targeting HMGB1 constitutes a favorable therapeutic strategy for inflammation and inflammatory diseases. Antagonists such as ethyl pyruvate inhibit HMGB1 by interfering with its cytoplasmic exportation, while others such as glycyrrhizin directly bind to HMGB1 and render it unavailable for its receptors. The fact that a mixture of different HMGB1 isoforms is present in the ECM poses a challenge in pinpointing the exact role of an individual antagonist. A more discriminative probe for HMGB1 may be necessary to advance our knowledge of HMGB1, HMGB1 antagonists, and inflammatory-related diseases.

High Mobility Group Box-1 (HMGB1): A Potential Target in Therapeutics

High mobility group box-1 (HMGB1) mainly belongs to the non-histone DNA-binding protein. It has been studied as a nuclear protein that is present in eukaryotic cells. From the HMG family, HMGB1 protein has been focused particularly for its pivotal role in several pathologies. HMGB-1 is considered as an essential facilitator in diseases such as sepsis, collagen disease, atherosclerosis, cancers, arthritis, acute lung injury, epilepsy, myocardial infarction, and local and systemic inflammation. Modulation of HMGB1 levels in the human body provides a way in the management of these diseases. Various strategies, such as HMGB1-receptor antagonists, inhibitors of its signalling pathway, antibodies, RNA inhibitors, vagus nerve stimulation etc. have been used to inhibit expression, release or activity of HMGB1. This review encompasses the role of HMGB1 in various pathologies and discusses its therapeutic potential in these pathologies.

microRNA-505 negatively regulates HMGB1 to suppress cell proliferation in renal cell carcinoma

microRNAs have been recognized to regulate a wide range of biology of renal cell carcinoma (RCC). Although miR-505 has been reported to play as a suppressor in several human tumors, the physiological function of miR-505 in RCC still remain unknown. Therefore, the role of miR-505 and relevant regulatory mechanisms were investigated in RCC in this study. Quantitative real-time polymerase chain reaction was conducted to detect the expression of miR-505 and high mobility group box 1 (HMGB1) in both RCC tissues and cell lines. Immunohistochemical staining was used to assess the correlation between HMGB1 expression and PCNA expression in RCC tissues. Subsequently, the effects of miR-505 on proliferation were determined in vitro using cell counting kit-8 proliferation assays and 5-ethynyl-2'-deoxyuridine incorporation. The molecular mechanism underlying the relevance between miR-505 and HMGB1 was confirmed by luciferase assay. Xenograft tumor formation was used to reflect the proliferative capacity of miR-505 in vivo experiments. Overall, a relatively lower miR-505 and higher HMGB1 expression in RCC specimens and cell lines were found. HMGB1 was verified as a direct target of miR-505 by luciferase assay. In vitro, overexpression of miR-505 negatively regulates HMGB1 to suppress the proliferation in Caki-1; meanwhile, knock-down of miR-505 negatively regulates HMGB1 to promote the proliferation in 769P. In addition, in vivo overexpression of miR-505 could inhibit tumor cell proliferation in RCC by xenograft tumor formation. Therefore, miR-505, as a tumor suppressor, negatively regulated HMGB1 to suppress the proliferation in RCC, and might serve as a novel therapeutic target for RCC clinical treatment.

HMGB1 as a Potential Biomarker and Therapeutic Target for Malignant Mesothelioma

Malignant mesothelioma (MM) is a rare, aggressive, and highly lethal cancer that is substantially induced by exposure to asbestos fibers. High-mobility group box 1 (HMGB1) is an intriguing proinflammatory molecule involved in MM. In this review, we describe the possible crucial roles of HMGB1 in carcinogenic mechanisms based on in vivo and in vitro experimental evidence and outline the clinical findings of epidemiological investigations regarding the possible roles of HMGB1 as a biomarker for MM. We conclude that novel strategies targeting HMGB1 may suppress MM cells and interfere with asbestos-induced inflammation.

MiR-1284 enhances sensitivity of cervical cancer cells to cisplatin via downregulating HMGB1

BACKGROUND

Chemotherapy is one of the commonest therapeutic method for cervical cancer. There are some common chemotherapy drugs, such as cisplatin, docetaxel, paclitaxel and selenium nanoparticle. microRNAs (miRNAs) have been verified to be regulators in various human cancers. This study aims to investigate the effects of miR-1284 on the cisplatin sensitivity of cervical cancer cells.

METHODS

The levels of miR-1284 in different tissues and cell lines were detected through using qRT-PCR analysis. Kaplan Meier analysis was utilized to analyze the influence of miR-1284 expression on the overall survival rate of cervical cancer patients. The biological effects of miR-1284 on the progression and chemosensitivity of cervical cancer were tested through conducting functional assays. Mechanism investigations were used to prove the binding relation between miR-1284 and HMGB1. Rescue assays were applied to demonstrate the effects of miR-1284-HMGB1 axis on chemosensitivity of cervical cancer cells.

RESULTS

miR-1284 was down-expressed in cervical cancer tissues and cell lines. Patients with low level of miR-1284 had low overall survival rate. Upregulation of miR-1284 suppressed proliferation and invasion, while promoted apoptosis. Moreover, upregulated miR-1284 enhanced sensitivity of cervical cancer cells to cisplatin. HMGB1 was a target gene of miR-1284. HMGB1 reversed the effects of miR-1284 on the progression and chemosensitivity of cervical cancer cells.

CONCLUSION

miR-1284 enhances sensitivity of cervical cancer cells to cisplatin via targeting HMGB1.