High-mobility group box 1 and cancer

Effects of daphnetin on the mechanism of epithelial-mesenchymal transition induced by HMGB1 in human lung adenocarcinoma cells (A549 cell line)

As a cancer with the highest incidence in recent years, lung cancer is mainly composed of three diseases: non-small cell lung cancer, small cell lung cancer and neuroendocrine tumor. The morbidity and mortality of this malignant tumor are the highest in both male and female populations worldwide. In my country, lung cancer has become the most common cancer disease and the leading cause of cancer death, so it is extremely important to find lung cancer therapeutic targets. Based on previous studies, we speculated that the TLR4-Myd88-NFκB pathway may be involved in hmgb1-induced EMT in A549 cells, and daphnetin may also inhibit hmgb1-induced EMT through the TLR4-Myd88-NFκB pathway in A549 cells, but related studies have not linked it to hmgb1-induced EMT. Therefore, the innovation of this study is to test these two conjectures and analyze how daphnetin affects the epithelial-mesenchymal transition (EMT) mechanism induced by HMGB1 in human lung adenocarcinoma cells (A549 cell line), aiming at lung adenocarcinoma cells, foundation for clinical treatment. The proliferation rate and the migrating cell number presented an obvious decrease in the HMGB1+TLR4-shRNA group and the HMGB1+daphnetin group relative to the HMGB1 group (P < 0.0001). The intracellular expression of TLR4, Myd88, NFκB, vimentin and snail1 proteins were significantly decreased (P < 0.001), while that of E-cadherin presented a remarkable increase (P < 0.001) in the HMGB1+TLR4-shRNA and HMGB1+daphnetin group compared with the HMGB1 group. TLR4-MyD88-NFκB pathway is associated with HMGB1-induced EMT in A549 cells. Daphnetin had an inhibitory effect on HMGB1-induced EMT via the TLR4-Myd88-NF-κB pathway in A549 cells.

The role of high mobility group box-1 on the development of diabetes complications: A plausible pharmacological target

BACKGROUND

Diabetes mellitus has emerged as a pressing global concern, with a notable increase in recent years. Despite advancements in treatment, existing medications struggle to halt the progression of diabetes and its associated complications. Increasing evidence underscores inflammation as a significant driver in the onset of diabetes mellitus. Therefore, perspectives on new therapies must consider shifting focus from metabolic stress to inflammation. High mobility group box (HMGB-1), a nuclear protein regulating gene expression, gained attention as an endogenous danger signal capable of sparking inflammatory responses upon release into the extracellular environment in the late 1990s.

PURPOSE

Given the parallels between inflammatory responses and type 2 diabetes (T2D) development, this review paper explores HMGB-1's potential involvement in onset and progression of diabetes complications. Specifically, we will review and update the understanding of HMGB-1 and its inflammatory pathways in insulin resistance, diabetic nephropathy, diabetic neuropathy, and diabetic retinopathy.

CONCLUSIONS

HMGB-1 and its receptors i.e. receptor for advanced glycation end-products (RAGE) and toll-like receptors (TLRs) present promising targets for antidiabetic interventions. Ongoing and future projects in this realm hold promise for innovative approaches targeting HMGB-1-mediated inflammation to ameliorate diabetes and its complications.

The crosstalk between immune cells and tumor pyroptosis: advancing cancer immunotherapy strategies

Pyroptosis is a cell death process characterized by cell swelling until membrane rupture and release of intracellular contents. As an effective tumor treatment strategy, inducing tumor cell pyroptosis has received widespread attention. In this process, the immune components within the tumor microenvironment play a key regulatory role. By regulating and altering the functions of immune cells such as cytotoxic T lymphocytes, natural killer cells, tumor-associated macrophages, and neutrophils, tumor cell pyroptosis can be induced. This article provides a comprehensive review of the molecular mechanisms of cell pyroptosis, the impact of the tumor immune microenvironment on tumor cell pyroptosis, and its mechanisms. It aims to gain an in-depth understanding of the communication between the tumor immune microenvironment and tumor cells, and to provide theoretical support for the development of new tumor immunotherapies.

Role of microRNA-505 during tumor progression and metastasis

Late diagnosis of cancer in advanced stages due to the lack of screening methods is considered as the main cause of poor prognosis and high mortality rate among these patients. Therefore, it is necessary to investigate the molecular tumor biology in order to introduce biomarkers that can be used in cancer screening programs and early diagnosis. MicroRNAs (miRNAs) have key roles in regulation of the cellular pathophysiological processes. Due to the high stability of miRNAs in body fluids, they are widely used as the non-invasive tumor markers. According to the numerous reports about miR-505 deregulation in a wide range of cancers, we investigated the role of miR-505 during tumor progression. It was shown that miR-505 mainly has the tumor suppressor functions through the regulation of signaling pathways, chromatin remodeling, and cellular metabolism. This review has an effective role in introducing miR-505 as a suitable marker for the early cancer diagnosis.

High mobility group box 1 mediates inflammatory responses in malignant peritoneal mesothelioma

BACKGROUND

Serum high mobility group box 1 (HMGB1) serves as a diagnostic biomarker for malignant peritoneal mesothelioma (MPM) patients, yet its diagnostic significance within MPM tumor tissues remains uncertain. This study aims to elucidate the roles of HMGB1 in MPM.

METHODS

HMGB1 expression analysis was conducted in both tumor and adjacent non-cancerous tissues collected from MPM patients. The two-year follow-up of MPM patients commenced from the diagnosis date. Inflammatory cytokine analysis was performed on these tissues, and Pearson correlation coefficient analysis was applied to examine variable relationships. In vitro assays included constructing an HMGB1 knockdown cell line, assessing cell viability, apoptosis, and inflammatory cytokine levels to delineate HMGB1's roles in MPM.

RESULTS

HMGB1 overexpression was observed in MPM tumor tissues, particularly in stages III-IV. Diagnostic implications of HMGB1 for MPM were evident, augmenting its diagnostic value. HMGB1 overexpression correlated with diminished survival rates. Positive correlations existed between inflammatory cytokines and HMGB1 in MPM tumor tissues and cell lines. Suppression of HMGB1 regulated cell growth and apoptosis in MPM cell lines.

CONCLUSION

HMGB1 exhibits diagnostic potential for MPM and modulates inflammatory responses within the disease context.

Recent advances of ultrasound-responsive nanosystems in tumor immunotherapy

Immunotherapy has revolutionized cancer treatment by boosting the immune system and preventing disease escape mechanisms. Despite its potential, challenges like limited response rates and adverse immune effects impede its widespread clinical adoption. Ultrasound (US), known for its safety and effectiveness in tumor diagnosis and therapy, has been shown to significantly enhance immunotherapy when used with nanosystems. High-intensity focused ultrasound (HIFU) can obliterate tumor cells and elicit immune reactions through the creation of immunogenic debris. Low-intensity focused ultrasound (LIFU) bolsters tumor immunosuppression and mitigates metastasis risk by concentrating dendritic cells. Ultrasonic cavitation (UC) produces microbubbles that can transport immune enhancers directly, thus strengthening the immune response and therapeutic impact. Sonodynamic therapy (SDT) merges nanotechnology with immunotherapy, using specialized sonosensitizers to kill cancer cells and stimulate immune responses, increasing treatment success. This review discusses the integration of ultrasound-responsive nanosystems in tumor immunotherapy, exploring future opportunities and current hurdles.

HMGB1 in the interplay between autophagy and apoptosis in cancer

Lysosome-mediated autophagy and caspase-dependent apoptosis are dynamic processes that maintain cellular homeostasis, ensuring cell health and functionality. The intricate interplay and reciprocal regulation between autophagy and apoptosis are implicated in various human diseases, including cancer. High-mobility group box 1 (HMGB1), a nonhistone chromosomal protein, plays a pivotal role in coordinating autophagy and apoptosis levels during tumor initiation, progression, and therapy. The regulation of autophagy machinery and the apoptosis pathway by HMGB1 is influenced by various factors, including the protein's subcellular localization, oxidative state, and interactions with binding partners. In this narrative review, we provide a comprehensive overview of the structure and function of HMGB1, with a specific focus on the interplay between autophagic degradation and apoptotic death in tumorigenesis and cancer therapy. Gaining a comprehensive understanding of the significance of HMGB1 as a biomarker and its potential as a therapeutic target in tumor diseases is crucial for advancing our knowledge of cell survival and cell death.

Pathogenesis and signaling pathways related to iodine-refractory differentiated thyroid cancer

Thyroid cancer is the most common malignant neoplasm within the endocrine system and the field of head and neck surgery. Although the majority of thyroid cancers, more than 90%, are well-differentiated thyroid carcinomas with a favourable prognosis, the escalating incidence of this disease has contributed to an increasing number of patients with a propensity for recurrent disease, rapid disease progression, and poor or no response to conventional treatments. These clinical challenges are commonly attributed to alterations in key thyroid oncogenes or signaling pathways, thereby initiating tumour cell dedifferentiation events, accompanied by reduced or virtually absent expression of the sodium/iodine symporter (NIS). As a result, the disease evolves into iodine-refractory differentiated thyroid cancer (RAIR-DTC), an entity that is insensitive to conventional radioiodine therapy. Despite being classified as a differentiated thyroid cancer, RAIR-DTC has an extremely poor clinical prognosis, with a 10-year survival rate of less than 10%. Therefore, it is of paramount importance to comprehensively elucidate the underlying pathogenesis of RAIR-DTC and provide specific targeted interventions. As the pathogenic mechanisms of RAIR-DTC remain elusive, here we aim to review recent advances in understanding the pathogenesis of RAIR-DTC and provide valuable insights for the development of future molecularly targeted therapeutic approaches.

A glimpse into let-7e roles in human disorders; friend or foe?

MicroRNAs (miRNAs) have been linked to abnormal expression and regulation in a number of diseases, including cancer. Recent studies have concentrated on miRNA Let-7e's significance in precision medicine for cancer screening and diagnosis as well as its prognostic and therapeutic potential. Differential let-7e levels in bodily fluids have the possibility to enable early detection of cancer utilizing less-invasive techniques, reducing biopsy-related risks. Although Let-7e miRNAs have been described as tumor suppressors, it is crucial to note that there exists proof to support their oncogenic activity in vitro and in in vivo. Let-7e's significance in chemo- and radiation treatment decisions has also been demonstrated. Let-7e can also prevent the synthesis of proinflammatory cytokines in a number of degenerative disorders, including musculoskeletal and neurological conditions. For the first time, an overview of the significance of let-7e in the prevention, detection, and therapy of cancer and other conditions has been given in the current review. Additionally, we focused on the specific molecular processes that underlie the actions of let-7e, more particularly, on malignant cells.

Andrographolide anti-proliferation and metastasis of hepatocellular carcinoma through LncRNA MIR22HG regulation

Hepatocellular carcinoma (HCC) treatment is a major challenge. Although andrographolide (Andro) has an anti-proliferation effect on HCC, its underlying mechanism is not yet elucidated, and whether Andro can inhibit HCC metastasis has not been reported. The present study aimed to clarify whether Andro inhibits SK-Hep-1 cell proliferation and HCC metastasis, and the mechanisms. The results showed that Andro significantly reduced the survival of HCC cells and tumor weight and volume in tumor-bearing nude mice. Andro also triggered apoptosis of HCC cells and upregulated MIR22HG, Cleaved Caspase 9/7/3 expression levels, and downregulated BCL-2 mRNA, BCL-2 expression levels. Knockdown of MIR22HG or overexpression of HuR attenuated the effects of Andro on the signal transduction of mitochondrial apoptotic pathway and proliferation ability in HCC cells. Moreover, Andro significantly reduced the invasive ability of the cells and the level of HCC cell lung metastasis, upregulated miR-22-3p expression level and downregulated HMGB1 and MMP-9 expression levels. MIR22HG or miR-22-3p knockdown attenuated the effects of Andro on the signaling of HMGB1/MMP-9 pathway and invasive ability in HCC cells, while the overexpression of HMGB1 attenuated the inhibitory effects of Andro on the MMP-9 expression level and invasive ability in HCC cells. Thus, the regulation of MIR22HG-HuR/BCL-2 and MIR22HG/HMGB1 signaling pathways is involved in the anti-HCC proliferation and metastasis effects of Andro. This study provided a new pharmacological basis for Andro in HCC treatment and, for the first time, identified a natural product molecule capable of positively regulating MIR22HG, which has a robust biological function.

HMGB1 promotes chemoresistance in small cell lung cancer by inducing PARP1-related nucleophagy

INTRODUCTION

Small cell lung cancer (SCLC) is prone to chemoresistance, which is closely related to genome homeostasis-related processes, such as DNA damage and repair. Nucleophagy is the elimination of specific nuclear substances by cells themselves and is responsible for maintaining genome and chromosome stability. However, the roles of nucleophagy in tumour chemoresistance have not been investigated.

OBJECTIVES

The aim of this work was to elucidate the mechanism of chemoresistance in SCLC and reverse this chemoresistance.

METHODS

RNA-seq data from SCLC cohorts, chemosensitive SCLC cells and the corresponding chemoresistant cells were used to discover genes associated with chemoresistance and patient prognosis. In vitro and in vivo experiments were performed to verify the effect of high-mobility group box 1 (HMGB1) knockdown or overexpression on the chemotherapeutic response in SCLC. The regulatory effect of HMGB1 on nucleophagy was then investigated by coimmunoprecipitation (co-IP) and mass spectrometry (MS), and the underlying mechanism was explored using pharmacological inhibitors and mutant proteins.

RESULTS

HMGB1 is a factor indicating poor prognosis and promotes chemoresistance in SCLC. Mechanistically, HMGB1 significantly increases PARP1-LC3 binding to promote nucleophagy via PARP1 PARylation, which leads to PARP1 turnover from DNA lesions and chemoresistance. Furthermore, chemoresistance in SCLC can be attenuated by blockade of the PARP1-LC3 interaction or PARP1 inhibitor (PARPi) treatment.

CONCLUSIONS

HMGB1 can induce PARP1 self-modification, which promotes the interaction of PARP1 with LC3 to promote nucleophagy and thus chemoresistance in SCLC. HMGB1 could be a predictive biomarker for the PARPi response in patients with SCLC. Combining chemotherapy with PARPi treatment is an effective therapeutic strategy for overcoming SCLC chemoresistance.

The Redox Protein High-Mobility Group Box 1 in Cell Death and Cancer

Significance: As a redox-sensitive protein, high-mobility group box 1 (HMGB1) is implicated in regulating stress responses to oxidative damage and cell death, which are closely related to the pathology of inflammatory diseases, including cancer. Recent Advances: HMGB1 is a nonhistone nuclear protein that acts as a deoxyribonucleic acid chaperone to control chromosomal structure and function. HMGB1 can also be released into the extracellular space and function as a damage-associated molecular pattern protein during cell death, including during apoptosis, necrosis, necroptosis, pyroptosis, ferroptosis, alkaliptosis, and cuproptosis. Once released, HMGB1 binds to membrane receptors to shape immune and metabolic responses. In addition to subcellular localization, the function and activity of HMGB1 also depend on its redox state and protein posttranslational modifications. Abnormal HMGB1 plays a dual role in tumorigenesis and anticancer therapy (e.g., chemotherapy, radiation therapy, and immunotherapy) depending on the tumor types and stages. Critical Issues: A comprehensive understanding of the role of HMGB1 in cellular redox homeostasis is important for deciphering normal cellular functions and pathological manifestations. In this review, we discuss compartmental-defined roles of HMGB1 in regulating cell death and cancer. Understanding these advances may help us develop potential HMGB1-targeting drugs or approaches to treat oxidative stress-related diseases or pathological conditions. Future Directions: Further studies are required to dissect the mechanism by which HMGB1 maintains redox homeostasis under different stress conditions. A multidisciplinary effort is also required to evaluate the potential applications of precisely targeting the HMGB1 pathway in human health and disease. Antioxid. Redox Signal. 39, 569-590.

Effect of tumor-associated macrophages on the pyroptosis of breast cancer tumor cells

Macrophages are immune cells with high plasticity that are widely distributed in all tissues and organs of the body. Under the influence of the immune microenvironment of breast tumors, macrophages differentiate into various germline lineages. They exert pro-tumor or tumor-suppressive effects by secreting various cytokines. Pyroptosis is mediated by Gasdermin family proteins, which form holes in cell membranes and cause a violent inflammatory response and cell death. This is an important way for the body to fight off infections. Tumor cell pyroptosis can activate anti-tumor immunity and inhibit tumor growth. At the same time, it releases inflammatory mediators and recruits tumor-associated macrophages (TAMs) for accumulation. Macrophages act as "mediators" of cytokine interactions and indirectly influence the pyroptosis pathway. This paper describes the mechanism of action on the part of TAM in affecting the pyroptosis process of breast tumor cells, as well as its key role in the tumor microenvironment. Additionally, it provides the basis for in-depth research on how to use immune cells to affect breast tumors and guide anti-tumor trends, with important implications for the prevention and treatment of breast tumors. Video Abstract.

Hmgb1 Silencing in the Amygdala Inhibits Pain-Related Behaviors in a Rat Model of Neuropathic Pain

Chronic pain presents a therapeutic challenge due to the highly complex interplay of sensory, emotional-affective and cognitive factors. The mechanisms of the transition from acute to chronic pain are not well understood. We hypothesized that neuroimmune mechanisms in the amygdala, a brain region involved in the emotional-affective component of pain and pain modulation, play an important role through high motility group box 1 (Hmgb1), a pro-inflammatory molecule that has been linked to neuroimmune signaling in spinal nociception. Transcriptomic analysis revealed an upregulation of Hmgb1 mRNA in the right but not left central nucleus of the amygdala (CeA) at the chronic stage of a spinal nerve ligation (SNL) rat model of neuropathic pain. Hmgb1 silencing with a stereotaxic injection of siRNA for Hmgb1 into the right CeA of adult male and female rats 1 week after (post-treatment), but not 2 weeks before (pre-treatment) SNL induction decreased mechanical hypersensitivity and emotional-affective responses, but not anxiety-like behaviors, measured 4 weeks after SNL. Immunohistochemical data suggest that neurons are a major source of Hmgb1 in the CeA. Therefore, Hmgb1 in the amygdala may contribute to the transition from acute to chronic neuropathic pain, and the inhibition of Hmgb1 at a subacute time point can mitigate neuropathic pain.

Panaxynol ameliorates cardiac ischemia/reperfusion injury by suppressing NLRP3-induced pyroptosis and apoptosis via HMGB1/TLR4/NF-κB axis

BACKGROUND AND PURPOSE

Panaxynol (PNN) is a common natural minor component in Umbelliferae plants. Many clinical studies have shown that PNN exhibits nutritional value and anti-inflammatory and other pharmacological activities. However, whether PNN can mediate cardiac ischemia/reperfusion injury (IRI) remains unclear. Here, we aimed to determine the potential effects of PNN on myocardial IRI.

METHODS

Myocardial IRI was stimulated in a mouse IRI model, and neonatal rat ventricle myocytes (NRVMs) were exposed to hypoxia/reoxygenation to construct in an vitro model. Myocardial infarction size, myocardial tissue injury, myocardial apoptotic index, hemodynamic monitoring, pyroptosis-related proteins, cardiac enzyme activities and inflammatory responses were examined to assess myocardial injury.

RESULTS

It was found that PNN administration markedly reduced myocardial infarct size and apoptosis, suppressed myocardial damage and cell pyroptosis, attenuated pro-inflammatory cytokines and neutrophil infiltration via NLRP3 inhibitor. More importantly, PNN treatment remarkably decreased the expression of TLR4/NF-κB pathway-associated proteins and NLRP3-related pyroptosis proteins by HMGB1 inhibitor. PNN also enhanced cell viability, reduced cardiac enzyme activities, suppressed apoptosis and attenuated inflammation in the isolated NRVMs. Furthermore, vitro studies indicated that MCC950 (a NLRP3 inhibitor) increased the anti-inflammatory and anti-apoptotic effects of PNN on NRVMs via HMGB1/TLR4 pathway.

CONCLUSION

To sum up, our results demonstrate that PNN exhibits a cardioprotective effect by modulating heart IRI-induced apoptosis and pyroptosis via HMGB1/TLR4/NF-κB pathway, thereby inhibiting NLRP3 inflammasome stimulation.

Autophagy and Breast Cancer: Connected in Growth, Progression, and Therapy

Despite an increase in the incidence of breast cancer worldwide, overall prognosis has been consistently improving owing to the development of multiple targeted therapies and novel combination regimens including endocrine therapies, aromatase inhibitors, Her2-targeted therapies, and cdk4/6 inhibitors. Immunotherapy is also being actively examined for some breast cancer subtypes. This overall positive outlook is marred by the development of resistance or reduced efficacy of the drug combinations, but the underlying mechanisms are somewhat unclear. It is interesting to note that cancer cells quickly adapt and evade most therapies by activating autophagy, a catabolic process designed to recycle damaged cellular components and provide energy. In this review, we discuss the role of autophagy and autophagy-associated proteins in breast cancer growth, drug sensitivity, tumor dormancy, stemness, and recurrence. We further explore how autophagy intersects and reduces the efficacy of endocrine therapies, targeted therapies, radiotherapy, chemotherapies as well as immunotherapy via modulating various intermediate proteins, miRs, and lncRNAs. Lastly, the potential application of autophagy inhibitors and bioactive molecules to improve the anticancer effects of drugs by circumventing the cytoprotective autophagy is discussed.

Voluntarily wheel running inhibits the growth of CRPC xenograft by inhibiting HMGB1 in mice

INTRODUCTION

Exercise has been proved to reduce the risk of recurrence and mortality of cancer. Emerging evidence indicated that exercise may regulate both systematical and local metabolism, immunity and other ways. Although the role of exercise in inhibiting castration-resistant prostate cancer is well established, the underlying mechanism remains unclear.

METHOD

Twenty C57BL/6 male mice were used to construct CRPC xenograft models and randomly divided into exercise group (n = 10) and control group (n = 10). After exercised with voluntarily wheel running for 21 days, the mice were sacrificed and the tumor tissues and serum were collected. TUNEL staining was used to detect the apoptosis of tumor cells. The expression of PI3K signal pathway and apoptosis related proteins were detected by Western blot. The expression of AR and HMGB1 were examined by Western blot and Immunohistochemical staining. IFN-γ, TNF-α, TGF-β, IL-4, IL-6, IL-10 in serum was examined using ELISA kits.

RESULTS

Voluntarily wheel running inhibited the growth of CRPC xenografts, inhibited the proliferation of tumor cells and promoted the apoptosis of tumor cells. HMGB1 levels in serum and tumor tissues were significantly reduced after exercise, which enhanced local immunity by inducing more leukocyte infiltration and inhibited systemic inflammatory response by regulating cytokines.

CONCLUSION

Voluntary wheel running can down-regulate the expression of HMGB1 in serum and transplanted tumor tissues, inhibit proliferation and promote apoptosis of tumor cells, enhance immune cell infiltration and systemic inflammatory response, and regulate local anti-tumor effects in tumor microenvironment.

Platinum-Based Regimens Are Active in Advanced Pediatric-Type Rhabdomyosarcoma in Adults and Depending on HMGB1 Expression

Rhabdomyosarcoma (RMS) in adults is a rare and aggressive disease, which lacks standard therapies for relapsed or advanced disease. This retrospective study aimed to describe the activity of BOMP-EPI (bleomycin, vincristine, methotrexate and cisplatin alternating with etoposide, cisplatin and ifosfamide), an alternative platinum-based regimen, in adult patients with relapsed/metastatic RMS. In the study, 10 patients with RMS with a median age at diagnosis of 20.8 years and a female/male distribution of 6/4 received a mean of 2.5 cycles of BOMP-EPI. The best RECIST response was a complete response in 1/10 (10%) patients, a partial response in 5/10 (50%), stable disease in 3/10 (30%) and progression in 1/10 (10%). With a median follow-up in the alive patients from the start of therapy of 30.5 months (15.7-258), all patients progressed with a median progression-free survival of 8.47 months (95% CI 8.1-8.8), and 7/10 patients died with a median overall survival of 24.7 months (95% CI 13.7-35.6). BOMP-EPI was an active chemotherapy regimen in adults with pediatric-type metastatic RMS, with outcomes in terms of survival that seem superior to what was expected for this poor-prognosis population. Low HMGB1 expression level was identified as a predictive factor of better response to this treatment.

Endogenous HMGB1 regulates GSDME-mediated pyroptosis via ROS/ERK1/2/caspase-3/GSDME signaling in neuroblastoma

Pyroptosis, a newly discovered mode of programmed cell death (PCD), is important in the regulation of cancer development. High mobility group box 1 (HMGB1) is a non-histone nuclear protein that is closely related to tumor development and chemotherapy resistance. However, whether endogenous HMGB1 regulates pyroptosis in neuroblastoma remains unknown. Here, we showed that HMGB1 showed ubiquitous higher expression in SH-SY5Y cells and clinical tumors, and was positively correlated with the risk factors of patients with neuroblastoma. Knockdown of GSDME or pharmacological inhibition of caspase-3 blocked pyroptosis and cytosolic translocation of HMGB1. Moreover, knockdown of HMGB1 inhibited cisplatin (DDP) or etoposide (VP16)-induced pyroptosis by decreasing GSDME-NT and cleaved caspase-3 expression, resulting in cell blebbing and LDH release. Knockdown of HMGB1 expression increased the sensitivity of SH-SY5Y cells to chemotherapy and switched pyroptosis to apoptosis. Furthermore, the ROS/ERK1/2/caspase-3/GSDME pathway was found to be functionally connected with DDP or VP16-induced pyroptosis. Hydrogen peroxide (H₂O₂, a ROS agonist) and EGF (an ERK agonist) promoted the cleavage of GSDME and caspase-3 in DDP or VP16 treatment cells, both of which were inhibited by HMGB1 knockdown. Importantly, these data were further supported by the in vivo experiment. Our study suggests that HMGB1 is a novel regulator of pyroptosis via the ROS/ERK1/2/caspase-3/GSDME pathway and a potential drug target for therapeutic interventions in neuroblastoma.

Suppression of high mobility group box 1 in B16F10 tumor does not inhibit the induction of neoantigen-specific T cells

Accumulated clinical data of immune checkpoint blockades have suggested the importance of neoantigens in cancer immunity. Tumor antigens are released from dead cancer cells together with cellular components, such as damage-associated molecular patterns (DAMPs), into the tumor microenvironment. We recently reported that high mobility group box 1 (HMGB1), a representative DAMP molecule, showed a negative impact on anti-tumor immunity. However, a positive role of HMGB1 in the initiation of innate and subsequent adaptive immunity has also been demonstrated; thus, the effects of HMGB1 on anti-tumor immunity have not been well understood. In this study, we identified nine immunogenic neoantigen epitopes of B16F10 murine melanoma cells and subsequently investigated the effects of suppression of HMGB1 on the induction of neoantigen-specific immunity using HMGB1-knockout tumors. Neoantigen-reactive T cells were expanded in B16F10 tumor-bearing mice, and T cell receptor repertoire analysis suggested that neoantigen-reactive T cells were oligo-clonally increased in B16F10 tumor bearers. An increase of neoantigen-reactive T cells and oligoclonal expansion of the T cells were similarly detected in HMGB1-knockout tumor-bearing mice. The induction of neoantigen-specific immunity under the suppression of HMGB1 in the tumor microenvironment shown in this study supports further development of combination therapy of HMGB1 suppression with neoantigen-targeted cancer immunotherapies, including immune checkpoint blockade therapy.

Guggulsterone Induces Apoptosis in Multiple Myeloma Cells by Targeting High Mobility Group Box 1 via Janus Activated Kinase/Signal Transducer and Activator of Transcription Pathway

Multiple myeloma (MM) is a hematological disorder characterized by the abnormal expansion of plasma cells in the bone marrow. Despite great advances over the past three decades in discovering the efficacious therapies for MM, the disease remains incurable for most patients owing to emergence of drug-resistant cancerous cells. Guggulsterone (GS), a phytosteroid, extracted from the gum resin of guggul plant, has displayed various anticancer activities in vitro and in vivo; however, the molecular mechanisms of its anticancer activity have not been evaluated in MM cells. Therefore, in this study, we investigated the anticancer activity of GS in various MM cell lines (U266, MM.1S, and RPMI 8226) and the mechanisms involved. GS treatment of MM cells caused inhibition of cell proliferation and induction of apoptotic cell death as indicated by increased Bax protein expression, activation of caspases, and cleavage of poly (ADP-ribose) polymerase. This was associated with the downregulation of various proliferative and antiapoptotic gene products, including cyclin D, Bcl-2, Bcl-xL, and X-linked inhibitor of apoptosis protein. GS also suppressed the constitutive and interleukin 6-induced activation of STAT3. Interestingly, the inhibition of Janus activated kinase or STAT3 activity by the specific inhibitors or by siRNA knockdown of STAT3 resulted in the downregulation of HMGB1, suggesting an association between GS, STAT3, and HMGB1. Finally, GS potentiated the anticancer effects of bortezomib (BTZ) in MM cells. Herein, we demonstrated that GS could be a potential therapeutic agent for the treatment of MM, possibly alone or in combination with BTZ.

Targeting lactate-related cell cycle activities for cancer therapy

Lactate has long been considered as a metabolic by-product of aerobic glycolysis for cancer. However, more and more studies have shown that lactate can regulate cancer progression via multiple mechanisms such as cell cycle regulation, immune suppression, energy metabolism and so on. A recent discovery of lactylation attracted a lot of attention and is already a hot topic in the cancer field. In this review, we summarized the latest functions of lactate and its underlying mechanisms in cancer. We also included our analysis of protein lactylation in different rat organs and compared them with other published lactylation data. The unresolved challenges in this field were discussed, and the potential application of these new discoveries of lactate-related cell cycle activities for cancer target therapy was speculated.

Inhibition of HMGB1/RAGE Signaling Reduces the Incidence of Medication-Related Osteonecrosis of the Jaw (MRONJ) in Mice

Medication-related osteonecrosis of the jaw (MRONJ) is a severe complication of antiresorptive or antiangiogenic medications, used in the treatment of bone malignancy or osteoporosis. Bone necrosis, mainly represented by osteocytic death, is always present in MRONJ sites; however, the role of osteocyte death in MRONJ pathogenesis is unknown. High mobility group box 1 (HMGB1) is a non-histone nucleoprotein that in its acetylated form accumulates in the cytoplasm, whereas non-acetylated HMGB1 localizes in the nucleus. SIRT1 deacetylase regulates cellular localization of HMGB1. Interestingly, HMGB1 is released during cell necrosis and promotes inflammation through signaling cascades, including activation of the RAGE receptor. Here, we utilized a well-established mouse MRONJ model that utilizes ligature-induced experimental periodontitis (EP) and treatment with either vehicle or zolendronic acid (ZA). Initially, we evaluated HMGB1-SIRT1 expression in osteocytes at 1, 2, and 4 weeks of treatment. Significantly increased cytoplasmic and perilacunar HMGB1 expression was observed at EP sites of ZA versus vehicle (Veh) animals at all time points. SIRT1 colocalized with cytoplasmic HMGB1 and presented a statistically significant increased expression at the EP sites of ZA animals for all time points. RAGE expression was significantly higher in the submucosal tissues EP sites of ZA animals compared with those in vehicle group. To explore the significance of increased cytoplasmic and extracellular HMGB1 and increased RAGE expression in MRONJ pathogenesis, we used pharmacologic inhibitors of these molecules. Combined HMGB1/RAGE inhibition resulted in lower MRONJ incidence with statistically significant decrease in osteonecrotic areas and bone exposure versus non-inhibitor treated ZA animals. Together, our data point to the role of HMGB1 as a central alarmin, overexpressed at early phase of MRONJ pathogenesis during osteocytic death. Moreover, HMGB1-RAGE pathway may represent a new promising therapeutic target in patients at high risk of MRONJ. © 2022 American Society for Bone and Mineral Research (ASBMR).

Hypoxia-induced HMGB1 promotes glioma stem cells self-renewal and tumorigenicity via RAGE

Glioma stem cells (GSCs) in the hypoxic niches contribute to tumor initiation, progression, and recurrence in glioblastoma (GBM). Hypoxia induces release of high-mobility group box 1 (HMGB1) from tumor cells, promoting the development of tumor. Here, we report that HMGB1 is overexpressed in human GBM specimens. Hypoxia promotes the expression and secretion of HMGB1 in GSCs. Furthermore, silencing HMGB1 results in the loss of stem cell markers and a reduction in self-renewal ability of GSCs. Additionally, HMGB1 knockdown inhibits the activation of RAGE-dependent ERK1/2 signaling pathway and arrests the cell cycle in GSCs. Consistently, FPS-ZM1, an inhibitor of RAGE, downregulates HMGB1 expression and the phosphorylation of ERK1/2, leading to a reduction in the proliferation of GSCs. In xenograft mice of GBM, HMGB1 knockdown inhibits tumor growth and promotes mouse survival. Collectively, these findings uncover a vital function for HMGB1 in regulating GSC self-renewal potential and tumorigenicity.

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Glioma stem cells overexpress HMGB1 in human glioblastoma

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Hypoxia induces the upregulation and release of HMGB1 in glioma stem cells

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HMGB1 promotes the self-renewal of glioma stem cells via RAGE

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Targeting HMGB1 inhibits the tumorigenesis of glioma stem cells

The mitochondrial unfolded protein response (UPRmt): shielding against toxicity to mitochondria in cancer

Mitochondria are essential for tumor growth and progression. However, the heavy demand for mitochondrial activity in cancer leads to increased production of mitochondrial reactive oxygen species (mtROS), accumulation of mutations in mitochondrial DNA, and development of mitochondrial dysfunction. If left unchecked, excessive mtROS can damage and unfold proteins in the mitochondria to an extent that becomes lethal to the tumor. Cellular systems have evolved to combat mtROS and alleviate mitochondrial stress through a quality control mechanism called the mitochondrial unfolded protein response (UPR^mt). The UPR^mt system is composed of chaperones and proteases, which promote protein folding or eliminate mitochondrial proteins damaged by mtROS, respectively. UPR^mt is conserved and activated in cancer in response to mitochondrial stress to maintain mitochondrial integrity and support tumor growth. In this review, we discuss how mitochondria become dysfunctional in cancer and highlight the tumor-promoting functions of key components of the UPR^mt.

A secretory form of Parkin-independent mitophagy contributes to the repertoire of extracellular vesicles released into the tumour interstitial fluid in vivo

We characterized the in vivo interstitial fluid (IF) content of extracellular vesicles (EVs) using the GFP-4T1 syngeneic murine cancer model to study EVs in-transit to the draining lymph node. GFP labelling confirmed the IF EV tumour cell origin. Molecular analysis revealed an abundance of IF EV-associated proteins specifically involved in mitophagy and secretory autophagy. A set of proteins required for sequential steps of fission-induced mitophagy preferentially populated the CD81+/PD-L1+ IF EVs; PINK1, TOM20, and ARIH1 E3 ubiquitin ligase (required for Parkin-independent mitophagy), DRP1 and FIS1 (mitochondrial peripheral fission), VDAC-1 (ubiquitination state triggers mitophagy away from apoptosis), VPS35, SEC22b, and Rab33b (vacuolar sorting). Comparing in vivo IF EVs to in vitro EVs revealed 40% concordance, with an elevation of mitophagy proteins in the CD81+ EVs for both murine and human cell lines subjected to metabolic stress. The export of cellular mitochondria proteins to CD81+ EVs was confirmed by density gradient isolation from the bulk EV isolate followed by anti-CD81 immunoprecipitation, molecular sieve chromatography, and MitoTracker export into CD81+ EVs. We propose the 4T1 in vivo model as a versatile tool to functionally characterize IF EVs. IF EV export of fission mitophagy proteins has broad implications for mitochondrial function and cellular immunology.

Human RNA-directed DNA methylation methylates high-mobility group box 1 protein-produced DNA gaps

Background: DNA sequences around HMGB1-produced DNA gaps are hypermethylates. DNA methylation of interspersed repetitive sequences (IRS) such as Alu elements can be established through AGO4-mediating, RNA-directed DNA methylation (RdDM). HMGB1 depletion, DNA gap reduction and global hypomethylation promote genomic instability. Methods: HMGB1, SIRT1, AGO4 and DNA gap colocalizations were evaluated. Then, Alu methylation was analyzed in HMGB1-deficient or HMGB1-overexpressing cells and Alu siRNA-transfected HMGB1-deficient cells. Results: HMGB1, SIRT1, AGO4 and DNA gap are colocalized in the nucleus. Moreover, HMGB1 or Alu siRNA increased Alu methylation, whereas Alu siRNA could not methylate HMGB1-deficient cells. Conclusion: AGO4 play a role in methylating DNA sequence around HMGB1-produced DNA gaps and localize DNA gap in IRS, and loss of intranuclear HMGB1 causes global hypomethylation.

HMGB3 inhibition by miR-142-3p/sh-RNA modulates autophagy and induces apoptosis via ROS accumulation and mitochondrial dysfunction and reduces the tumorigenic potential of human breast cancer cells

AIMS

High mobility group box (HMGB) family proteins, HMGB1, HMGB2, HMGB3, and HMGB4 are oncogenic. The oncogenic nature of HMGB1 is characterized by its association with autophagy, ROS, and MMP. Since HMGB3 is its paralog, we hypothesized that it might also modulate autophagy, ROS, and MMP. Hence, we targeted HMGB3 using its shRNA or miR-142-3p and assessed the changes in autophagy, ROS, MMP, and tumorigenic properties of human breast cancer cells.

MAIN METHODS

Cell viability was assessed by resazurin staining and annexin-V/PI dual staining was used for confirming apoptosis. Colony formation, transwell migration, invasion and luciferase reporter (for miRNA-target validation) assays were also performed. ROS and MMP were detected using DHE and MitoTracker dyes, respectively. A zebrafish xenograft model was used to assess the role of miR-142-3p on in vivo metastatic potential of breast cancer cells.

KEY FINDINGS

Breast cancer tissues from Indian patients and TCGA samples exhibit overexpression of HMGB3. miR-142-3p binds to 3' UTR of HMGB3, leading to its downregulation that subsequently inhibits colony formation and induces apoptosis involving increased ROS accumulation and decreased MMP, phospho-mTOR and STAT3. Our findings show that HMGB3 is directly involved in the miR-142-3p-mediated disruption of autophagy and induction of apoptotic cell death via modulation of LC3, cleaved PARP and Bcl-xL. In addition, miR-142-3p inhibited migration, invasion and metastatic potential of breast cancer cells.

SIGNIFICANCE

Our findings highlighted the role of HMGB3, for the first time, in the modulation of autophagy and apoptosis in human breast cancer cells, and these results have therapeutic implications.

Role of high-mobility group box 1 in cancer

High-mobility group box 1 (HMGB1) is a non-histone nuclear protein in most eukaryocytes. Inside the nucleus, HMGB1 plays an important role in several DNA events such as DNA repair, transcription, telomere maintenance, and genome stability. While outside the nucleus, it fulfils more complicated functions, including promoting cell proliferation, inflammation, angiogenesis, immune tolerance and immune escape, which may play a pro-tumoral role.Meanwhile, HMGB1 acts as an anti-tumoral protein by regulating immune cell recruitment and inducing immunogenic cell death (ICD) during the carcinogenesis process. Therefore, abnormal expression of HMGB1 is associated with oncogenesis, development, and metastasis of cancer, which may play a dual role of pro-tumor and anti-tumor.

HMGB1-mediated autophagy promotes gefitinib resistance in human non-small cell lung cancer

Non-small cell lung cancer (NSCLC) ranks the first in incidence and mortality among malignant tumors in China. Molecular targeted therapies such as gefitinib, an oral inhibitor of the epidermal growth factor receptor tyrosine kinase, have shown significant benefits in patients with advanced NSCLC. However, most patients have unsatisfactory outcomes due to the development of drug resistance, and there is an urgent need to better understand the pathways involved in the resistance mechanisms. In this study, we found that HMGB1 is highly expressed in drug-resistant cells and confers to gefitinib resistance in NSCLC cells via activating autophagy process. Gefitinib upregulates HMGB1 expression in time-dependent and dose-dependent manners in human NSCLC cells. RNA interference-mediated knockdown of HMGB1 reduces PC9GR cell viability, induces apoptosis, and partially restores gefitinib sensitivity. Mechanistic analyses indicate that elevated HMGB1 expression contributes to gefitinib resistance by inducing autophagy. Thus, our results suggest that HMGB1 is an autophagy regulator and plays a key role in gefitinib resistance of NSCLC.

Role of Extracellular High-Mobility Group Box-1 as a Therapeutic Target of Gastric Cancer

Background: High-mobility group box-1 (HMGB1) is involved in the tumorigenesis and metastasis of various cancers. The present study investigated the roles of extracellular HMGB1 in the progression of gastric cancer (GC) and the therapeutic effects of recombinant human soluble thrombomodulin (rTM) targeting HMGB1. Methods: The effects of extracellular HMGB1 and rTM on GC cells were assessed using proliferation and Transwell assays. Their effects on local tumor growth and metastasis were evaluated using subcutaneous tumor and liver metastasis mouse models, respectively. Plasma HMGB1 concentrations in GC patients were measured using ELISA. The relationships between plasma HMGB1 concentrations and the prognosis and clinicopathological factors of patients were also investigated. Results: GC proliferation, migration, and invasion abilities were promoted by increases in extracellular HMGB1 concentrations and alleviated by rTM. In the subcutaneous tumor model, local tumor growth was promoted by the addition of rhHMGB1 and alleviated by rTM. Similar changes occurred in the liver metastasis model. Recurrence-free survival (p < 0.01) and overall survival (p = 0.01) were significantly worse in patients with high plasma HMGB1 concentrations. Conclusion: Plasma HMGB1 concentrations are a prognostic marker in GC patients. Extracellular HMGB1 promotes cancer progression and has potential as a novel treatment target in GC cells for rTM.

Development and Regeneration of Muscle, Tendon, and Myotendinous Junctions in Striated Skeletal Muscle

Owing to a rapid increase in aging population in recent years, the deterioration of motor function in older adults has become an important social problem, and several studies have aimed to investigate the mechanisms underlying muscle function decline. Furthermore, structural maintenance of the muscle–tendon–bone complexes in the muscle attachment sites is important for motor function, particularly for joints; however, the development and regeneration of these complexes have not been studied thoroughly and require further elucidation. Recent studies have provided insights into the roles of mesenchymal progenitors in the development and regeneration of muscles and myotendinous junctions. In particular, studies on muscles and myotendinous junctions have—through the use of the recently developed scRNA-seq—reported the presence of syncytia, thereby suggesting that fibroblasts may be transformed into myoblasts in a BMP-dependent manner. In addition, the high mobility group box 1—a DNA-binding protein found in nuclei—is reportedly involved in muscle regeneration. Furthermore, studies have identified several factors required for the formation of locomotor apparatuses, e.g., tenomodulin (Tnmd) and mohawk (Mkx), which are essential for tendon maturation.

Investigating key cell types and molecules dynamics in PyMT mice model of breast cancer through a mathematical model

The most common kind of cancer among women is breast cancer. Understanding the tumor microenvironment and the interactions between individual cells and cytokines assists us in arriving at more effective treatments. Here, we develop a data-driven mathematical model to investigate the dynamics of key cell types and cytokines involved in breast cancer development. We use time-course gene expression profiles of a mouse model to estimate the relative abundance of cells and cytokines. We then employ a least-squares optimization method to evaluate the model's parameters based on the mice data. The resulting dynamics of the cells and cytokines obtained from the optimal set of parameters exhibit a decent agreement between the data and predictions. We perform a sensitivity analysis to identify the crucial parameters of the model and then perform a local bifurcation on them. The results reveal a strong connection between adipocytes, IL6, and the cancer population, suggesting them as potential targets for therapies.

The MicroRNA-Based Strategies to Combat Cancer Chemoresistance via Regulating Autophagy

Chemoresistance frequently occurs in cancer treatment, which results in chemotherapy failure and is one of the most leading causes of cancer-related death worldwide. Understanding the mechanism of chemoresistance and exploring strategies to overcome chemoresistance have become an urgent need. Autophagy is a highly conserved self-degraded process in cells. The dual roles of autophagy (pro-death or pro-survival) have been implicated in cancers and chemotherapy. MicroRNA (miRNA) is a class of small non-coding molecules that regulate autophagy at the post-transcriptional level in cancer cells. The association between miRNAs and autophagy in cancer chemoresistance has been emphasized. In this review, we focus on the dual roles of miRNA-mediated autophagy in facilitating or combating chemoresistance, aiming to shed lights on the potential role of miRNAs as targets to overcome chemoresistance.

Ferroptosis in Cancer Immunotherapy—Implications for Hepatocellular Carcinoma

Ferroptosis is a recently recognized iron-dependent form of non-apoptotic regulated cell death (RCD) characterized by lipid peroxide accumulation to lethal levels. Cancer cells, which show an increased iron dependency to enable rapid growth, seem vulnerable to ferroptosis. There is also increasing evidence that ferroptosis might be immunogenic and therefore could synergize with immunotherapies. Hepatocellular carcinoma (HCC) is the most common primary liver tumor with a low survival rate due to frequent recurrence and limited efficacy of conventional chemotherapies, illustrating the urgent need for novel drug approaches or combinatorial strategies. Immunotherapy is a new treatment approach for advanced HCC patients. In this setting, ferroptosis inducers may have substantial clinical potential. However, there are still many questions to answer before the mystery of ferroptosis is fully unveiled. This review discusses the existing studies and our current understanding regarding the molecular mechanisms of ferroptosis with the goal of enhancing response to immunotherapy of liver cancer. In addition, challenges and opportunities in clinical applications of potential candidates for ferroptosis-driven therapeutic strategies will be summarized. Unraveling the role of ferroptosis in the immune response could benefit the development of promising anti-cancer therapies that overcome drug resistance and prevent tumor metastasis.

Knockout of high-mobility group box 1 in B16F10 melanoma cells induced host immunity-mediated suppression of in vivo tumor growth

High-mobility group box 1 (HMGB1) has been reported as a damage-associated molecular pattern (DAMP) molecule that is released from damaged or dead cells and induces inflammation and subsequent innate immunity. However, the role of HMGB1 in the anti-tumor immunity is unclear since inflammation in the tumor microenvironment also contributes to tumor promotion and progression. In the present study, we established HMGB1-knockout clones from B16F10 and CT26 murine tumors by genome editing using the CRISPR/Cas9 system and investigated the role of HMGB1 in anti-tumor immunity. We found that (1) knockout of HMGB1 in the tumor cells suppressed in vivo, but not in vitro, tumor growth, (2) the suppression of the in vivo tumor growth was mediated by CD8 T cells, and (3) infiltration of CD8 T cells, macrophages and dendritic cells into the tumor tissues was accelerated in HMGB1-knockout tumors. These results demonstrated that knockout of HMGB1 in tumor cells converted tumors from poor infiltration of immune cells called “cold” to “immune-inflamed” or “hot” and inhibited in vivo tumor growth mediated by cytotoxic T lymphocytes. Infiltration of immune cells to the tumor microenvironment is an important step in the series known as the cancer immunity cycle. Thus, manipulation of tumor-derived HMGB1 might be applicable to improve the clinical outcomes of cancer immunotherapies, including immune checkpoint blockades and cancer vaccine therapies.

Autophagy-associated HMGB-1 as a novel potential circulating non-invasive diagnostic marker for detection of Urothelial Carcinoma of Bladder

Urothelial carcinoma of bladder (UBC), a highly prevalent urological malignancy associated with high mortality and recurrence rate. Standard diagnostic method currently being used is cystoscopy but its invasive nature and low sensitivity stresses for identifying predictive diagnostic marker. Autophagy, a cellular homeostasis maintaining process, is usually dysregulated in cancer and its role is still enigmatic in UBC. In this study, 30 UBC patients and healthy controls were enrolled. Histopathologically confirmed tumor and adjacent normal tissue were acquired from patients. Molecular expression and tissue localization of autophagy-associated molecules (HMGB-1, RAGE, beclin, LC-3, and p62) were investigated. Serum HMGB-1 concentration was measured in UBC patients and healthy controls. ROC curves were plotted to evaluate diagnostic potential. Transcript, protein, and IHC expression of HMGB-1, RAGE, beclin, and LC-3 displayed upregulated expression, while p62 was downregulated in bladder tumor tissue. Serum HMGB-1 levels were elevated in UBC patients. Transcript and circulatory levels of HMGB-1 showed positive correlation and displayed a positive trend with disease severity. Upon comparison with clinicopathological parameters, HMGB-1 emerged as molecule of statistical significance to exhibit association. HMGB-1 exhibited optimum sensitivity and specificity in serum. The positive correlation between tissue and serum levels of HMGB-1 showcases serum as a representation of in situ scenario, suggesting its clinical applicability for non-invasive testing. Moreover, optimum sensitivity and specificity displayed by HMGB-1 along with significant association with clinicopathological parameters makes it a potential candidate to be used as diagnostic marker for early detection of UBC but requires further validation in larger cohort.

Helicobacter hepaticus Infection Promotes the Progression of Liver Preneoplasia in BALB/c Mice via the Activation and Accumulation of High-Mobility Group Box-1

It has been documented that Helicobacter hepaticus (H. hepaticus) infection is linked to chronic hepatitis and fibrosis in male BALB/c mice. However, the mechanism underlying the mice model of H. hepaticus–induced hepatocellular carcinoma is not fully known. In this study, male BALB/c mice were infected with H. hepaticus for 3, 6, 12, and 18 months. H. hepaticus colonization, histopathology, expression of proinflammatory cytokines, key signaling pathways, and protein downstream high-mobility group box-1 (HMGB1) in the liver were examined. Our data suggested that the H. hepaticus colonization level in the colon and liver progressively increased over the duration of the infection. H. hepaticus–induced hepatic inflammation and fibrosis were aggravated during the infection, and hepatic preneoplasia developed in the liver of infected mice at 12 and 18 months post-inoculation (MPI). H. hepaticus infection increased the levels of alanine aminotransferase and aspartate aminotransferase in the infected mice. In addition, the mRNA levels of IL-6, Tnf-α, Tgf-β, and HMGB1 were significantly elevated in the liver of H. hepaticus–infected mice from 3 to 18 MPI as compared to the controls. In addition, Ki67 was increased throughout the duration of the infection. Furthermore, HMGB1 protein was activated and translocated from the nucleus to the cytoplasm in the hepatocytes and activated the proteins of signal transducers and activators of transcription 3 (Stat3) and mitogen-activated protein kinase (MAPK) [extracellular regulated protein kinases 1/2 (Erk1/2) and mitogen-activated protein kinase p38 (p38)] upon H. hepaticus infection. In conclusions, these data demonstrated that male BALB/c mice infected with H. hepaticus are prone to suffering hepatitis and developing into hepatic preneoplasia. To verify the effect of HMGB1 in the progression of liver preneoplasia, mice were infected by H. hepaticus for 2 months before additional HMGB1 recombinant adenovirus treatment. All mice were sacrificed at 4 MPI, and the sera and liver tissues from all of the mice were collected. Immunology and histopathology evaluation showed that HMGB1 knockdown attenuated the H. hepaticus–induced hepatic and fibrosis at 4 MPI. Therefore, we showed that H. hepaticus–induced liver preneoplasia is closely correlated with the activation and accumulation of HMGB1.

AGE/Non-AGE Glycation: An Important Event in Rheumatoid Arthritis Pathophysiology

Rheumatoid arthritis (RA) is a chronic inflammatory, autoimmune disease that gradually affects the synovial membrane and joints. Many intrinsic and/or extrinsic factors are crucial in making RA pathology challenging throughout the disease. Substantial enzymatic or non-enzymatic modification of proteins driving inflammation has gained a lot of interest in recent years. Endogenously modified glycated protein influences disease development linked with AGEs/non-AGEs and is reported as a disease marker. In this review, we summarized current knowledge of the differential abundance of glycated proteins by compiling and analyzing a variety of AGE and non-AGE ligands that bind with RAGE to activate multi-faceted inflammatory and oxidative stress pathways that are pathobiologically associated with RA-fibroblast-like synoviocytes (RA-FLS). It is critical to comprehend the connection between oxidative stress and inflammation generation, mediated by glycated protein, which may bind to the receptor RAGE, activate downstream pathways, and impart immunogenicity in RA. It is worth noting that AGEs and non-AGEs ligands play a variety of functions, and their functionality is likely to be more reliant on pathogenic states and severity that may serve as biomarkers for RA. Screening and monitoring of these differentially glycated proteins, as well as their stability in circulation, in combination with established pre-clinical characteristics, may aid or predict the onset of RA.

HMGB1 Promotes Resistance to Doxorubicin in Human Hepatocellular Carcinoma Cells by Inducing Autophagy via the AMPK/mTOR Signaling Pathway

Chemoresistance remains as a major hindrance in the treatment of hepatocellular carcinoma (HCC). High mobility group box protein 1 (HMGB1) enhances autophagic flux and protects tumor cells from apoptosis, which results in acquired drug resistance. However, the exact mechanisms underlying HMGB1-modulated autophagy in HCC chemoresistance remain to be defined. In the present study, we found that administration of doxorubicin (DOX) significantly promoted HMGB1 expression and induced HMGB1 cytoplasmic translocation in human HCC cell lines BEL7402 and SMMC7721, which enhanced autophagy that contributes to protecting HCC cells from apoptosis and increasing drug resistance. Moreover, we observed HMGB1 translocation and elevation of autophagy in DOX-resistant BEL7402 and SMMC7721 cells. Additionally, inhibition of HMGB1 and autophagy increased the sensitivities of BEL-7402 and SMMC-7721 cells to DOX and re-sensitized their DOX-resistant cells. Subsequently, we confirmed with HMGB1 regulated autophagy by activating the 5ʹ adenosine monophosphate-activated protein kinase (AMPK)/mTOR pathway. In summary, our results indicate that HMGB1 promotes acquired DOX resistance in DOX-treated BEL7402 and SMMC7721 cells by enhancing autophagy through the AMPK/mTOR signaling pathway. These findings provide the proof-of-concept that HMGB1 inhibitors might be an important targeted treatment strategy for HCC.

Subcellular localization of HMGB1 in human cholangiocarcinoma: correlation with tumor stage

Cholangiocarcinoma (CCA) is a malignant disease with a poor prognosis, and several studies have been conducted using different molecular markers as a tool for CCA diagnosis, including Clonorchis sinensis (CS)-CCA. We initially identified the expression profiles of the three markers of interest, HMGB1, SOX9, and YAP1, using GSE (GSE76297 and GSE32958) datasets. Upregulated levels of these three proteins were detected in CCA samples compared to those in normal samples. To clarify this issue, 24 human CCA tissues with paired adjacent normal tissues were evaluated using immunohistochemical staining. Of the three markers, the total cellular staining intensities were scanned, and subcellular localization was scored in the nuclear and cytoplasmic regions. The intensities of HMGB1, SOX9, and YAP1 were elevated in CCA tissues than the adjacent normal tissues. Individual scoring of subcellular localization revealed that the expression levels of HMGB1 (nucleus) and YAP1 (nucleus and cytoplasm) were significantly different from the pathologic M stage. Moreover, the translocation pattern was categorized using "site-index", and the results demonstrated that the overexpression of HMGB1 and SOX9 was mostly observed in both the nucleus and cytoplasm, whereas YAP1 was predominantly expressed in the cytoplasm of tumor cells. Interestingly, the site index of HMGB1 was moderately correlated with the tumor stage (r = 0.441, p = 0.031). These findings imply that the overexpression of subcellular HMGB1 could be associated with the metastatic status of patients with CS-CCA, which was shown to be effective for CS-CCA prognosis.

Antagonism of inhibitors of apoptosis proteins reveals a novel, immune response-based therapeutic approach for T-cell lymphoma

Tolinapant (ASTX660) is a potent, nonpeptidomimetic antagonist of cellular inhibitor of apoptosis proteins 1 and 2 (cIAP1/2) and X-linked IAP, which is currently being evaluated in a phase 2 study in T-cell lymphoma (TCL) patients. Tolinapant has demonstrated evidence of single-agent clinical activity in relapsed/refractory peripheral TCL and cutaneous TCL. To investigate the mechanism of action underlying the single-agent activity observed in the clinic, we have used a comprehensive translational approach integrating in vitro and in vivo models of TCL confirmed by data from human tumor biopsies. Here, we show that tolinapant acts as an efficacious immunomodulatory molecule capable of inducing complete tumor regression in a syngeneic model of TCL exclusively in the presence of an intact immune system. These findings were confirmed in samples from our ongoing clinical study showing that tolinapant treatment can induce changes in gene expression and cytokine profile consistent with immune modulation. Mechanistically, we show that tolinapant can activate both the adaptive and the innate arms of the immune system through the induction of immunogenic forms of cell death. In summary, we describe a novel role for IAP antagonists as immunomodulatory molecules capable of promoting a robust antitumor immune response in TCL.

Cancer molecular biology and strategies for the design of cytotoxic gold(I) and gold(III) complexes: a tutorial review

This tutorial review highlights key principles underpinning the design of selected metallodrugs to target specific biological macromolecules (DNA and proteins). The review commences with a descriptive overview of the eukaryotic cell cycle and the molecular biology of cancer, particularly apoptosis, which is provided as a necessary foundation for the discovery, design, and targeting of metal-based anticancer agents. Drugs which target DNA have been highlighted and clinically approved metallodrugs discussed. A brief history of the development of mainly gold-based metallodrugs is presented prior to addressing ligand systems for stabilizing and adding functionality to bio-active gold(I) and gold(III) complexes, particularly in the burgeoning field of anticancer metallodrugs. Concepts such as multi-modal and selective cytotoxic agents are covered where necessary for selected compounds. The emerging role of carbenes as the ligand system of choice to achieve these goals for gold-based metallodrug candidates is highlighted prior to closing the review with comments on some future directions that this research field might follow. The latter section ultimately emphasizes the importance of understanding the fate of metal complexes in cells to garner key mechanistic insights.

A Mathematical Model of Breast Tumor Progression Based on Immune Infiltration

Breast cancer is the most prominent type of cancer among women. Understanding the microenvironment of breast cancer and the interactions between cells and cytokines will lead to better treatment approaches for patients. In this study, we developed a data-driven mathematical model to investigate the dynamics of key cells and cytokines involved in breast cancer development. We used gene expression profiles of tumors to estimate the relative abundance of each immune cell and group patients based on their immune patterns. Dynamical results show the complex interplay between cells and molecules, and sensitivity analysis emphasizes the direct effects of macrophages and adipocytes on cancer cell growth. In addition, we observed the dual effect of IFN-γ on cancer proliferation, either through direct inhibition of cancer cells or by increasing the cytotoxicity of CD8+ T-cells.

Peritumoral B cells drive proangiogenic responses in HMGB1-enriched esophageal squamous cell carcinoma

Several B-cell subsets with distinct functions and polarized cytokine profiles that extend beyond antibody production have been reported in different cancers. Here we have demonstrated that proliferating B cells were predominantly found in the peritumoral region of esophageal squamous cell carcinoma (ESCC). These B cells were enriched in tumor nests with high expression of high-mobility group box 1 (HMGB1). High densities of peritumoral proliferating B cells and concomitantly high intratumoral HMGB1 expression showed improved prognostic significance, surpassing prognostic stratification of ESCC patients based on HMGB1 positivity alone. This striking association led us to set up models to test whether cancer-derived HMGB1 could shape tumor microenvironment via modulation on B cells. Overexpression of HMGB1 in ESCC cell lines (KYSE510 and EC18) enhanced proliferation and migration of B cells. Transcriptomic analysis showed that migratory B cells exhibited high enrichment of proangiogenic genes. VEGF expression in proliferating B cells was induced upon co-culture of HMGB1-overexpressing tumor cells and B cells. Secretome array profiling of conditioned media (CM) from the co-culture revealed rich expression of proangiogenic proteins. Consequently, incubation of human umbilical vein endothelial cells with CM promoted angiogenesis in tube formation and migration assays. HMGB1 inhibitor, glycyrrhizin, abolishes all the observed proangiogenic phenotypes. Finally, co-injection of B cells and CM with HMGB1-overexpressing tumor cells, but not with glycyrrhizin, significantly enhanced tumor growth associated with increased microvascular density in ESCC xenograft mice model. Our results indicate that cancer-derived HMGB1 elevates angiogenesis in ESCC by shifting the balance toward proangiogenic signals in proliferating B cells.

Mathematical Model for Delayed Responses in Immune Checkpoint Blockades

We introduce a set of ordinary differential equations (ODEs) that qualitatively reproduce delayed responses observed in immune checkpoint blockade therapy (e.g. anti-CTLA-4 ipilimumab). This type of immunotherapy has been at the forefront of novel and promising cancer treatments over the past decade and was recognised by the 2018 Nobel Prize in Medicine. Our model describes the competition between effector T cells and non-effector T cells in a tumour. By calibrating a small subset of parameters that control immune checkpoint expression along with the patient's immune-system cancer readiness, our model is able to simulate either a complete absence of patient response to treatment, a quick anti-tumour T cell response (within days) or a delayed response (within months). Notably, the parameter space that generates a delayed response is thin and must be carefully calibrated, reflecting the observation that a small subset of patients experience such reactions to checkpoint blockade therapies. Finally, simulations predict that the anti-tumour T cell storm that breaks the delay is very short-lived compared to the length of time the cancer is able to stay suppressed. This suggests the tumour may subsist off an environment hostile to effector T cells; however, these cells are-at rare times-able to break through the tumour immunosuppressive defences to neutralise the tumour for a prolonged period. Our simulations aim to qualitatively describe the delayed response phenomenon without making precise fits to particular datasets, which are limited. It is our hope that our foundational model will stimulate further interest within the immunology modelling field.

Hypoxia and the Receptor for Advanced Glycation End Products (RAGE) Signaling in Cancer

Hypoxia is characterized by an inadequate supply of oxygen to tissues, and hypoxic regions are commonly found in solid tumors. The cellular response to hypoxic conditions is mediated through the activation of hypoxia-inducible factors (HIFs) that control the expression of a large number of target genes. Recent studies have shown that the receptor for advanced glycation end products (RAGE) participates in hypoxia-dependent cellular adaptation. We review recent evidence on the role of RAGE signaling in tumor biology under hypoxic conditions.

Molecular Characteristics of RAGE and Advances in Small-Molecule Inhibitors

Receptor for advanced glycation end-products (RAGE) is a member of the immunoglobulin superfamily. RAGE binds and mediates cellular responses to a range of DAMPs (damage-associated molecular pattern molecules), such as AGEs, HMGB1, and S100/calgranulins, and as an innate immune sensor, can recognize microbial PAMPs (pathogen-associated molecular pattern molecules), including bacterial LPS, bacterial DNA, and viral and parasitic proteins. RAGE and its ligands stimulate the activations of diverse pathways, such as p38MAPK, ERK1/2, Cdc42/Rac, and JNK, and trigger cascades of diverse signaling events that are involved in a wide spectrum of diseases, including diabetes mellitus, inflammatory, vascular and neurodegenerative diseases, atherothrombosis, and cancer. Thus, the targeted inhibition of RAGE or its ligands is considered an important strategy for the treatment of cancer and chronic inflammatory diseases.

Aspirin Actions in Treatment of NSAID-Exacerbated Respiratory Disease

Non-steroidal Anti-inflammatory drugs (NSAID)-exacerbated respiratory disease (N-ERD) is characterized by nasal polyposis, chronic rhinosinusitis, adult-onset asthma and hypersensitive reactions to cyclooxygenase-1 (COX-1) inhibitors. Among the available treatments for this disease, a combination of endoscopic sinus surgery followed by aspirin desensitization and aspirin maintenance therapy has been an effective approach. Studies have shown that long-term aspirin maintenance therapy can reduce the rate of nasal polyp recurrence in patients with N-ERD. However, the exact mechanism by which aspirin can both trigger and suppress airway disease in N-ERD remains poorly understood. In this review, we summarize current knowledge of aspirin effects in N-ERD, cardiovascular disease, and cancer, and consider potential mechanistic pathways accounting for the effects of aspirin in N-ERD.

Antigene and Antiproliferative Effects of Triplex-Forming Oligonucleotide (TFO) Targeted on hmgb1 Gene in Human Hepatoma Cells

BACKGROUND

The high mobility group box 1 (hmgb1) is one of the frequently over-expressed genes whose aberrant expression is reported in a number of human cancers. Various strategies are underway to inhibit hmgb1 expression in cancer cells having considerable therapeutic value.

OBJECTIVE

The present work involves selective transcriptional inhibition of the hmgb1 gene using selective DNA triplex structure-based gene technology. Here, the promoter region of the hmgb1 gene at position (-183 to -165) from the transcription start site as a target was selected using bioinformatic tools.

METHODS

The DNA triplex formation by the DNA of the target gene and TFO was confirmed using UV absorption spectroscopy, Circular Dichroism, and Isothermal Calorimetry.

RESULTS

Treatment of HepG2 cell with specific Triplex-forming Oligonucleotide significantly downregulated HMGB1 expression level at mRNA and protein levels by 50%, while the classical anticancer drugs, actinomycin/ adriamycin as positive controls showed 65% and the combination of TFO and drug decreased by 70%. The anti-proliferative effects of TFO correlated well with the fact of accumulation of cells in the Go phase and apoptotic cell death. Further, the binding of anti-cancer drugs to hmgb1 is stronger in DNA triplex state as compared to hmgb1 alone, suggesting the combination therapy as a better option.

CONCLUSION

Therefore, the ability of hmgb1 targeted triplex-forming oligonucleotide in combination with triplex selective anticancer drug holds promise in the treatment of malignancies associated with hmgb1 overexpression. The result obtained may open up new vistas to provide a basis for the rational drug design and searching for high-affinity ligands with a high triplex selectivity.