Circulating immunogenic cell death biomarkers HMGB1 and RAGE in breast cancer patients during neoadjuvant chemotherapy

Mitochondria-Targeting Type-I Photodrug: Harnessing Caspase-3 Activity for Pyroptotic Oncotherapy

Precise control of cellular signaling events during programmed cell death is crucial yet challenging for cancer therapy. The modulation of signal transduction in cancer cells holds promise but is limited by the lack of efficient, biocompatible, and spatiotemporally controllable approaches. Here we report a photodynamic strategy that modulates both apoptotic and pyroptotic cell death by altering caspase-3 protein activity and the associated signaling crosstalk. This strategy employs a mitochondria-targeting, near-infrared activatable probe (termed M-TOP) that functions via a type-I photochemical mechanism. M-TOP is less dependent on oxygen and more effective in treating drug-resistant cancer cells, even under hypoxic conditions. Our study shows that higher doses of M-TOP induce pyroptotic cell death via the caspase-3/gasdermin-E pathway, whereas lower doses lead to apoptosis. This photodynamic method is effective across diverse gasdermin-E-expressing cancer cells. Moreover, the M-TOP mediated shift from apoptotic to pyroptotic modulation can evoke a controlled inflammatory response, leading to a robust yet balanced immune reaction. This effectively inhibits both distal tumor growth and postsurgical tumor recurrence. This work demonstrates the feasibility of modulating intracellular signaling through the rational design of photodynamic anticancer drugs.

Elucidating the molecular basis of ATP-induced cell death in breast cancer: Construction of a robust prognostic model

BACKGROUND

Breast cancer is a multifaceted and formidable disease with profound public health implications. Cell demise mechanisms play a pivotal role in breast cancer pathogenesis, with ATP-triggered cell death attracting mounting interest for its unique specificity and potential therapeutic pertinence.

AIM

To investigate the impact of ATP-induced cell death (AICD) on breast cancer, enhancing our understanding of its mechanism.

METHODS

The foundational genes orchestrating AICD mechanisms were extracted from the literature, underpinning the establishment of a prognostic model. Simultaneously, a microRNA (miRNA) prognostic model was constructed that mirrored the gene-based prognostic model. Distinctions between high- and low-risk cohorts within mRNA and miRNA characteristic models were scrutinized, with the aim of delineating common influence mechanisms, substantiated through enrichment analysis and immune infiltration assessment.

RESULTS

The mRNA prognostic model in this study encompassed four specific mRNAs: P2X purinoceptor 4, pannexin 1, caspase 7, and cyclin 2. The miRNA prognostic model integrated four pivotal miRNAs: hsa-miR-615-3p, hsa-miR-519b-3p, hsa-miR-342-3p, and hsa-miR-324-3p. B cells, CD4+ T cells, CD8+ T cells, endothelial cells, and macrophages exhibited inverse correlations with risk scores across all breast cancer subtypes. Furthermore, Kyoto Encyclopedia of Genes and Genomes analysis revealed that genes differentially expressed in response to mRNA risk scores significantly enriched 25 signaling pathways, while miRNA risk scores significantly enriched 29 signaling pathways, with 16 pathways being jointly enriched.

CONCLUSION

Of paramount significance, distinct mRNA and miRNA signature models were devised tailored to AICD, both potentially autonomous prognostic factors. This study's elucidation of the molecular underpinnings of AICD in breast cancer enhances the arsenal of potential therapeutic tools, offering an unparalleled window for innovative interventions. Essentially, this paper reveals the hitherto enigmatic link between AICD and breast cancer, potentially leading to revolutionary progress in personalized oncology.

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.

Dietary and serum advanced glycation end-products and clinical outcomes in breast cancer

One in five women with breast cancer will relapse despite ideal treatment. Body weight and physical activity are strongly associated with recurrence risk, thus lifestyle modification is an attractive strategy to improve prognosis. Trials of dietary modification in breast cancer are promising but the role of specific diets is unclear, as is whether high-quality diet without weight loss can impact prognosis. Advanced glycation end-products (AGEs) are compounds produced in the body during sugar metabolism. Exogenous AGEs, such as those found in food, combined with endogenous AGEs, make up the total body AGE load. AGEs deposit in tissues over time impacting cell signaling pathways and altering protein functions. AGEs can be measured or estimated in the diet and measured in blood through their metabolites. Studies demonstrate an association between AGEs and breast cancer risk and prognosis. Here, we review the clinical data on dietary and serum AGEs in breast cancer.

Role of HMGB1 and its associated signaling pathways in human malignancies

The High-Mobility Group Box-1 (HMGB1), a non-histone chromatin-associated protein, plays a crucial role in cancer growth and response to therapy as it retains a pivotal role in promoting both cell death and survival. HMGB1 has been reported to regulate several signaling pathways engaged in inflammation, genome stability, immune function, cell proliferation, cell autophagy, metabolism, and apoptosis. However, the association between HMGB1 and cancer is complex and its mechanism in tumorigenesis needs to be further elucidated. This review aims to understand the role of HMGB1 in human malignancies and discuss the signaling pathways linked to this process to provide a comprehensive understanding on the association of HMGB1 with carcinogenesis. Further, we will review the role of HMGB1 as a target/biomarker for cancer therapy, the therapeutic strategies used to target this protein, and its potential role in preventing or treating cancers. In light of the recent growing evidence linking HMGB1 to cancer progression, we think that it may be suggested as a novel and emergent therapeutic target for cancer therapy. Hence, HMGB1 warrants paramount investigation to comprehensively map its role in tumorigenesis.

Neoadjuvant chemotherapy reduces the levels of HMGB1 and E-cadherin in patients with breast cancer

This study investigated the changes in serum tumor marker levels in patients with breast cancer (BC) after neoadjuvant chemotherapy (NACT) and their potential as prognostic factors in NACT. A total of 134 consecutive patients with BC treated at our hospital between January 2019 and December 2021 were retrospectively analyzed. Patients were treated with NACT based on the docetaxel, epirubicin, and cyclophosphamide (TEC) regimen and assessed for marker levels, T cell subsets, and therapeutic outcomes. Receiver operating characteristic (ROC) curves were constructed to evaluate the predictive performance of the markers. Outcome assessments showed that NACT effectively reduced the tumor size, leading to increased complete remission, partial remission, stable disease, and significantly reduced disease progression. Improved immune function has also been observed after NACT. The levels of two (E-cadherin and HMGB1) out of five markers (CA153, CK19, CEA, E-cadherin, and HMGB1) were significantly reduced after NACT before surgery compared with those at admission, suggesting that NACT modulates the levels of biomarkers. ROC analysis revealed that the area under the curve (AUC) of HMGB1 and E-cadherin combination was 0.87 for discrimination of therapeutic response with a sensitivity and specificity of 91.3% and 88.4%, respectively. Serum tumor marker levels were reduced after NACT in patients with BC. The reduction was most prominent for HMGB1, followed by E-cadherin. These biomarkers can be used to predict the therapeutic response to NACT with an AUC of 0.87, thus offering a new tool to monitor treatment progress in NACT for patients with BC.

A cooperative nano-CRISPR scaffold potentiates immunotherapy via activation of tumour-intrinsic pyroptosis

Efficient cancer immunotherapy depends on selective targeting of high bioactivity therapeutic agents to the tumours. However, delivering exogenous medication might prove difficult in clinical practice. Here we report a cooperative Nano-CRISPR scaffold (Nano-CD) that utilizes a specific sgRNA, selected from a functional screen for triggering endogenous GDSME expression, while releasing cisplatin to initiate immunologic cell death. Mechanistically, cascade-amplification of the antitumor immune response is prompted by the adjuvantic properties of the lytic intracellular content and enhanced by the heightened GDSME expression, resulting in pyroptosis and the release of tumor associated antigens. Neither of the single components provide efficient tumour control, while tumor growth is efficiently inhibited in primary and recurrent melanomas due to the combinatorial effect of cisplatin and self-supplied GSDME. Moreover, Nano-CD in combination with checkpoint blockade creates durable immune memory and strong systemic anti-tumor immune response, leading to disease relapse prevention, lung metastasis inhibition and increased survival in mouse melanomas. Taken together, our therapeutic approach utilizes CRISPR-technology to enable cell-intrinsic protein expression for immunotherapy, using GDSME as prototypic immune modulator. This nanoplatform thus can be applied to modulate further immunological processes for therapeutic benefit.

Alarmins and Related Molecules in Elective Surgery

Surgery is associated with alterations of alarmins' and related molecules' levels. The aim of this study was to investigate which biomarkers are most involved in surgery. The studied group consisted of 58 patients with inguinal or umbilical hernia or cholecystolithiasis and 21 healthy controls for compa-rison. We also added seven acute patients with appendicitis, cholecystitis and incarcerated hernia. Serum concentrations of soluble receptor of advanced glycation end-products (sRAGE), extracellular newly identified receptor for advanced glycation end-products binding protein (EN-RAGE), calprotectin, high mobility group box 1 (HMGB1) and interleukin 6 (IL-6) were analysed by ELISA before and after surgery. Preoperative concentrations of calprotectin were significantly decreased while concentrations of sRAGE were significantly increased in patients compared to controls; the concentrations of EN-RAGE and HMGB1 did not differ significantly. IL-6 levels were undetectable in elective patients preoperatively and in controls. Postoperatively, there was a significant increase of EN-RAGE, calprotectin, HMGB1, and IL-6 and a significant decrease of sRAGE compared to preoperative levels. In acute patients, all tested molecules except for sRAGE were significantly increased preoperatively, and sRAGE was significantly decreased. In contrast, after surgery, we could observe a further increase in IL-6; the other biomarkers did not differ significantly. We can conclude that the concentrations of all tested biomarkers are significantly influenced by elective surgery. The postoperative levels of all tested molecules increase except for sRAGE, whose level is significantly decreased after surgery. In acute states, these molecules are already increased, and the influence of surgery is, apart from IL-6, insignificant.

Dying of Stress: Chemotherapy, Radiotherapy, and Small-Molecule Inhibitors in Immunogenic Cell Death and Immunogenic Modulation

Innovative strategies to re-establish the immune-mediated destruction of malignant cells is paramount to the success of anti-cancer therapy. Accumulating evidence suggests that radiotherapy and select chemotherapeutic drugs and small molecule inhibitors induce immunogenic cell stress on tumors that results in improved immune recognition and targeting of the malignant cells. Through immunogenic cell death, which entails the release of antigens and danger signals, and immunogenic modulation, wherein the phenotype of stressed cells is altered to become more susceptible to immune attack, radiotherapies, chemotherapies, and small-molecule inhibitors exert immune-mediated anti-tumor responses. In this review, we discuss the mechanisms of immunogenic cell death and immunogenic modulation and their relevance in the anti-tumor activity of radiotherapies, chemotherapies, and small-molecule inhibitors. Our aim is to feature the immunological aspects of conventional and targeted cancer therapies and highlight how these therapies may be compatible with emerging immunotherapy approaches.

Immunogenic cell death-related classifications in breast cancer identify precise immunotherapy biomarkers and enable prognostic stratification

Background: Immunogenic cell death (ICD) remodels the tumor immune microenvironment, plays an inherent role in tumor cell apoptosis, and promotes durable protective antitumor immunity. Currently, appropriate biomarker-based ICD immunotherapy for breast cancer (BC) is under active exploration. Methods: To determine the potential link between ICD genes and the clinical risk of BC, TCGA-BC was used as the training set and GSE58812 was used as the validation set. Gene expression, consistent clustering, enrichment analysis, and mutation omics analyses were performed to analyze the potential biological pathways of ICD genes involved in BC. Furthermore, a risk and prognosis model of ICD was constructed to evaluate the correlation between risk grade and immune infiltration, clinical stage, and survival prognosis. Results: We identified two ICD-related subtypes by consistent clustering and found that the C2 subtype was associated with good survival prognosis, abundant immune cell infiltration, and high activity of immune biological processes. Based on this, we constructed and validated an ICD risk and prognosis model of BC, including ATG5, HSP90AA1, PIK3CA, EIF2AK3, MYD88, IL1R1, and CD8A. This model can effectively predict the survival rate of patients with BC and is negatively correlated with the immune microenvironment and clinical stage. Conclusion: This study provides new insights into the role of ICD in BC. The novel classification risk model based on ICD in BC established in this study can aid in estimating the potential prognosis of patients with BC and the clinical outcomes of immunotherapy and postulates targets that are more useful in comprehensive treatment strategies.

Current and Future Therapies for Immunogenic Cell Death and Related Molecules to Potentially Cure Primary Breast Cancer

Simple Summary

How a cure for primary breast cancer after (neo)adjuvant therapy can be achieved at the molecular level remains unclear. Immune activation by anticancer drugs may contribute to the eradication of residual tumor cells by postoperative (neo)adjuvant chemotherapy. In addition, chemotherapy-induced immunogenic cell death (ICD) may result in long-term immune activation by memory effector T cells, leading to the curing of primary breast cancer. In this review, we discuss the molecular mechanisms by which anticancer drugs induce ICD and immunogenic modifications for antitumor immunity and targeted therapy against damage-associated molecular patterns. Our aim was to gain a better understanding of how to eradicate residual tumor cells treated with anticancer drugs and cure primary breast cancer by enhancing antitumor immunity with immune checkpoint inhibitors and vaccines.

Abstract

How primary breast cancer can be cured after (neo)adjuvant therapy remains unclear at the molecular level. Immune activation by anticancer agents may contribute to residual tumor cell eradication with postsurgical (neo)adjuvant chemotherapy. Chemotherapy-induced immunogenic cell death (ICD) may result in long-term immune activation with memory effector T cells, leading to a primary breast cancer cure. Anthracycline and taxane treatments cause ICD and immunogenic modulations, resulting in the activation of antitumor immunity through damage-associated molecular patterns (DAMPs), such as adenosine triphosphate, calreticulin, high mobility group box 1, heat shock proteins 70/90, and annexin A1. This response may eradicate residual tumor cells after surgical treatment. Although DAMP release is also implicated in tumor progression, metastasis, and drug resistance, thereby representing a double-edged sword, robust immune activation by anticancer agents and the subsequent acquisition of long-term antitumor immune memory can be essential components of the primary breast cancer cure. This review discusses the molecular mechanisms by which anticancer drugs induce ICD and immunogenic modifications for antitumor immunity and targeted anti-DAMP therapy. Our aim was to improve the understanding of how to eradicate residual tumor cells treated with anticancer drugs and cure primary breast cancer by enhancing antitumor immunity with immune checkpoint inhibitors and vaccines.

From Immunogenic Cell Death to Immunogenic Modulation: Select Chemotherapy Regimens Induce a Spectrum of Immune-Enhancing Activities in the Tumor Microenvironment

Cancer treatment has rapidly entered the age of immunotherapy, and it is becoming clear that the effective therapy of established tumors necessitates rational multi-combination immunotherapy strategies. But even in the advent of immunotherapy, the clinical role of standard-of-care chemotherapy regimens still remains significant and may be complementary to emerging immunotherapeutic approaches. Depending on dose, schedule, and agent, chemotherapy can induce immunogenic cell death, resulting in the release of tumor antigens to stimulate an immune response, or immunogenic modulation, sensitizing surviving tumor cells to immune cell killing. While these have been previously defined as distinct processes, in this review we examine the published mechanisms supporting both immunogenic cell death and immunogenic modulation and propose they be reclassified as similar effects termed "immunogenic cell stress." Treatment-induced immunogenic cell stress is an important result of cytotoxic chemotherapy and future research should consider immunogenic cell stress as a whole rather than just immunogenic cell death or immunogenic modulation. Cancer treatment strategies should be designed specifically to take advantage of these effects in combination immunotherapy, and novel chemotherapy regimens should be designed and investigated to potentially induce all aspects of immunogenic cell stress.

Restoring the Immunity in the Tumor Microenvironment: Insights into Immunogenic Cell Death in Onco-Therapies

Immunogenic cell death (ICD) elicited by cancer therapy reshapes the tumor immune microenvironment. A long-term adaptative immune response can be initiated by modulating cell death by therapeutic approaches. Here, the major hallmarks of ICD, endoplasmic reticulum (ER) stress, and damage-associated molecular patterns (DAMPs) are correlated with ICD inducers used in clinical practice to enhance antitumoral activity by suppressing tumor immune evasion. Approaches to monitoring the ICD triggered by antitumoral therapeutics in the tumor microenvironment (TME) and novel perspective in this immune system strategy are also reviewed to give an overview of the relevance of ICD in cancer treatment.

Soluble High Mobility Group Box 1 (HMGB1) Is a Promising Biomarker for Prediction of Therapy Response and Prognosis in Advanced Lung Cancer Patients

BACKGROUND

High mobility group box 1 protein (HMGB1) is known for its significant elevation in a multitude of tumors and benign diseases. In this study, we investigated the relevance of soluble HMGB1 for the prediction and monitoring of therapy response as well as the estimation of prognosis in advanced lung cancer.

MATERIALS AND METHODS

In a retrospective study, HMGB1 levels were assessed by an enzyme-linked immunosorbent assay (ELISA) in the sera of 96 patients with advanced lung cancer (79 non-small-cell lung carcinoma (NSCLC); 14 small cell lung carcinoma (SCLC), 3 Mesothelioma) prior to cycles 1, 2, and 3 of chemotherapy and correlated with radiological therapy response after 2 and 4 cycles as well as with overall survival. In addition, HMGB1 was compared with established tumor markers cytokeratin 19-fragments (CYFRA 21-1), carcinoembryonic antigen (CEA) and neuron specific enolase (NSE).

RESULTS

While pretherapeutic HMGB1 levels were not predictive or prognostically relevant in NSCLC patients, HMGB1 values prior to cycles 2 and 3 as well as kinetics from cycle 1 to 2 discriminated significantly between patients with good (remission and stable disease) and poor response (progression). Performance of HMGB1 in receiver operating characteristic (ROC) analyses of NSCLC patients, with areas under the curve (AUCs) of 0.690 at cycle 2 and 0.794 at cycle 3 as well as sensitivities of 34.4% and 37.5%, respectively, for progression at 90% specificity, was comparable with the best tumor-associated antigen CYFRA 21-1 (AUCs 0.719 and 0.799; sensitivities of 37.5% and 41.7%, respectively). Furthermore, high concentrations of HMGB1 at cycles 2 and 3 were associated with shorter overall survival in NSCLC patients.

CONCLUSION

Soluble HMGB1 is a promising biomarker for prediction of therapy response and prognosis in advanced NSCLC patients.

Chemoresistance in Breast Cancer Patients Associated With Changes in P2X7 and A2A Purinergic Receptors in CD8+ T Lymphocytes

Breast cancer (BRCA) is the most frequent cancer type that afflicts women. Unfortunately, despite all the current therapeutic strategies, many patients develop chemoresistance hampering the efficacy of treatment. Hence, an early indicator of therapy efficacy might aid in the search for better treatment and patient survival. Although emerging evidence indicates a key role of the purinergic receptors P2X7 and A2A in cancer, less is known about their involvement in BRCA chemoresistance. In this sense, as the chemotherapeutic treatment stimulates immune system response, we evaluated the expression and function of P2X7 and A2A receptors in CD8⁺ T cells before and four months after BRCA patients received neoadjuvant chemotherapy. The results showed an increase in the levels of expression of P2X7 and a decrease in the expression of A2A in CD8⁺ T cells in non-chemoresistant (N-CHR) patients, compared to chemoresistant (CHR) patients. Interestingly, in CHR patients, reduced expression of P2X7 occurs along with a decrease in the CD62L shedding and the production of IFN-γ. In the case of the A2A function, the inhibition of IFN-γ production was not observed after chemotherapy in CHR patients. A possible relationship between the modulation of the expression and function of the P2X7 and A2A receptors was found, according to the molecular subtypes, where the patients that were triple-negative and human epidermal growth factor receptor 2 (HER2)-enriched presented more alterations. Comorbidities such as overweight/obesity and type 2 diabetes mellitus (T2DM) participate in the abnormalities detected. Our results demonstrate the importance of purinergic signaling in CD8⁺ T cells during chemoresistance, and it could be considered to implement personalized therapeutic strategies.

MicroRNA-505-3p inhibits development of glioma by targeting HMGB1 and regulating AKT expression

Previous studies have reported that microRNA (miR)-505 exhibits important effect in human cancers. However, the regulatory mechanism of miR-505-3p/high-mobility group box 1 (HMGB1) axis is still unclear in glioma. Therefore, the regulatory mechanism of miR-505-3p/HMGB1 axis in glioma was illuminated. Expression of miR-505-3p and HMGB1 was observed by RT-qPCR. Protein expression was measured by western blot analysis. Dual luciferase assay was performed to confirm the relationship between miR-505-3p and HMGB1. The function of miR-505-3p was investigated by MTT and Transwell assays. Expression of miR-505-3p was reduced in glioma, which was related to poor clinical outcomes and prognosis in glioma patients. Moreover, overexpression of miR-505-3p suppressed proliferation, migration and invasion of glioma cells. In addition, HMGB1 was confirmed as a direct target of miR-505-3p, and miR-505-3p inhibited the development of glioma by targeting HMGB1. Furthermore, miR-505-3p blocked EMT suppressing p-AKT expression in glioma cells. In conclusion, miR-505-3p inhibited the development of glioma by targeting HMGB1 and regulating AKT expression.

Current status of immune checkpoint inhibition in early-stage NSCLC

Immune checkpoint inhibition (ICI) immunotherapy has revolutionized the approach to metastatic non-small-cell lung cancer (NSCLC). In particular, antibodies blocking the inhibitory immune checkpoints programmed death 1 (PD-1) and its ligand (PD-L1) are associated with higher response rates, improved overall survival and better tolerability as compared with conventional cytotoxic chemotherapy. Recently, ICI has moved from the second-line to the first-line setting for many patients with non-oncogene-addicted NSCLC, either alone or in combination with chemotherapy. The next logical step is to examine this therapy in patients with non-metastatic NSCLC to improve long-term overall survival and cure rates. For patients with unresectable stage III NSCLC, ICI with durvalumab after concurrent chemoradiotherapy has brought a major improvement in 2-year progression-free and overall survival, which holds promise for an improved cure rate. As the relapse pattern in patients with completely resected early-stage NSCLC is predominantly systemic, high expectations rest on the integration of ICI therapy in their treatment approach. A large number of studies with adjuvant or neo-adjuvant ICI are ongoing and will be discussed here. The advent of stereotactic ablative radiotherapy has brought a valid alternative treatment of patients unfit for or not willing to undergo surgery. Data on combining systemic therapy and stereotactic ablative radiotherapy are virtually non-existent, but there is a strong biological rationale to combine radiotherapy and ICI therapy. Early findings in small feasibility studies are promising and now need to be explored in well-designed phase III trials.

Johnny on the Spot-Chronic Inflammation Is Driven by HMGB1

Although much has been made of the role of HMGB1 acting as an acute damage associated molecular pattern (DAMP) molecule, prompting the response to tissue damage or injury, it is also released at sites of chronic inflammation including sites of infection, autoimmunity, and cancer. As such, the biology is distinguished from homeostasis and acute inflammation by the recruitment and persistence of myeloid derived suppressor cells, T regulatory cells, fibrosis and/or exuberant angiogenesis depending on the antecedents and the other individual inflammatory partners that HMGB1 binds and focuses, including IL-1β, CXCL12/SDF1, LPS, DNA, RNA, and sRAGE. High levels of HMGB1 released into the extracellular milieu and its persistence in the microenvironment can contribute to the pathogenesis of many if not all autoimmune disorders and is a key factor that drives inflammation further and worsens symptoms. HMGB1 is also pivotal in the maintenance of chronic inflammation and a “wound healing” type of immune response that ultimately contributes to the onset of carcinogenesis and tumor progression. Exosomes carrying HMGB1 and other instructive molecules are released and shape the response of various cells in the chronic inflammatory environment. Understanding the defining roles of REDOX, DAMPs and PAMPs, and the host response in chronic inflammation requires an alternative means for positing HMGB1's central role in limiting and focusing inflammation, distinguishing chronic from acute inflammation.

miR-505 acts as a tumor suppressor in gastric cancer progression through targeting HMGB1

Gastric cancer (GC) is a frequent type of malignant tumor worldwide. GC metastasis results in the majority of clinical treatment failures. MicroRNAs (miRNA) are identified to exhibit crucial roles in GC. Our current study aimed to explore the biological roles of miR-505 in GC progression. It was observed that miR-505 was robustly decreased in GC cells compared with human normal gastric epithelial GES-1 cells. Overexpression of miR-505 was able to repress GC progression in AGS and BGC-823 cells. In addition, high-mobility group box 1 (HMGB1) has been identified as a crucial oncogene in several cancer types. By carrying out bioinformatics analysis, HMGB1 was predicted as a direct target of miR-505. Meanwhile, HMGB1 was found to be significantly increased in GC cells and it was confirmed in our study that miR-505 can directly target HMGB1 in vitro. miR-505 mimics can inhibit HMGB1 messenger RNA and protein expression dramatically. Subsequently, knockdown of HMGB1 can inhibit GC cell proliferation, colony formation, and induce cell apoptosis. Furthermore, HMGB1 silence suppressed GC cell migration and invasion greatly in vitro. Finally, it was validated that miR-505 can inhibit GC progression by targeting HMGB1 in vivo. Taken these together, it was indicated that miR-505/HMGB1 axis was involved in the development of GC. miR-505 can serve as a potential prognostic indicator in GC therapy.

Clinical prognostic significance of serum high mobility group box-1 protein in patients with community-acquired pneumonia

Objective

To investigate the relationship between serum high mobility group box-1 protein (HMGB-1) levels and prognosis in patients with community-acquired pneumonia (CAP).

Methods

This prospective study included 35 patients who attended our hospital from January 2016 to December 2016. Pneumonia severity was defined by pneumonia severity index (PSI). Serum levels of C-reactive protein (CRP), cortisol, and HMGB-1 were analyzed in relation to disease severity and clinical outcome.

Results

High HMGB-1 levels were associated with high cortisol levels. High HMGB-1 and high cortisol were both significantly associated with high white blood cell count and high serum CRP, compared with low HMGB-1 and low cortisol, respectively. PSI score and 30-day mortality were also significantly higher in patients with high HMGB-1 or high cortisol levels compared with patients with low HMGB-1 or cortisol levels, respectively. CRP, cortisol, and HMGB-1 levels were all significantly higher in patients who died compared with survivors.

Conclusion

HMGB-1 was associated with clinical outcomes and was an independent risk factor for 30-day mortality in patients with CAP. Serum HMGB-1 levels were also positively correlated with serum levels of cortisol. These results demonstrate a role for HMGB-1 in CAP, and suggest possible new therapeutic targets for patients with CAP.

Realizing the Clinical Potential of Immunogenic Cell Death in Cancer Chemotherapy and Radiotherapy

Immunogenic cell death (ICD), which is triggered by exposure of tumor cells to a limited range of anticancer drugs, radiotherapy, and photodynamic therapy, represents a recent innovation in the revitalized and burgeoning field of oncoimmunnotherapy. ICD results in the cellular redistribution and extracellular release of damage-associated molecular patterns (DAMPs), which have the potential to activate and restore tumor-targeted immune responses. Although a convincing body of evidence exists with respect to the antitumor efficacy of ICD in various experimental systems, especially murine models of experimental anticancer immunotherapy, evidence for the existence of ICD in the clinical setting is less compelling. Following overviews of hallmark developments, which have sparked the revival of interest in the field of oncoimmunotherapy, types of tumor cell death and the various DAMPs most prominently involved in the activation of antitumor immune responses, the remainder of this review is focused on strategies which may potentiate ICD in the clinical setting. These include identification of tumor- and host-related factors predictive of the efficacy of ICD, the clinical utility of combinatorial immunotherapeutic strategies, novel small molecule inducers of ICD, novel and repurposed small molecule immunostimulants, as well as the critical requirement for validated biomarkers in predicting the efficacy of ICD.

The immune response to secondary necrotic cells

When apoptotic cells are not cleared in an efficient and timely manner, they progress to secondary necrosis and lose their membrane integrity. This results in a leakage of immunostimulatory, danger associated molecular patterns (DAMPs), similar to accidental (or primary) necrosis. However, primary necrosis is a sudden event with an inadvertent release of almost unmodified DAMPs. Secondary necrotic cells, in contrast, have gone through various modifications during the process of apoptosis. Recent research revealed that the molecules released from the cytoplasm or exposed on the cell surface differ between primary necrosis, secondary necrosis, and regulated necrosis such as necroptosis. This review gives an overview of these differences and focusses their effects on the immune response. The implications to human physiology and diseases are manifold and will be discussed in the context of cancer, neurodegenerative disorders and autoimmunity.

LncRNA MALAT1 induces colon cancer development by regulating miR-129-5p/HMGB1 axis

Recent studies have exhibited significant roles of lncRNAs in various tumors' development, including colon cancer. Our study focused on the biological roles of lncRNA MALAT1 in colon cancer. In our study, it was demonstrated that MALAT1 was upregulated in human colon cancer cell lines including Lovo, HCT116, SW480, and HT29 cells compared to the normal human intestinal epithelial HIEC cells. Moreover, we observed that miR-129-5p was downregulated in colon cancer cells with a significant increase of HMGB1 expression. Inhibition of MALAT1 can inhibit the proliferation of colon cancer SW480 and HCT116 cells and next, bioinformatics analysis was used to predict the target microRNA of MALAT1. miR-129-5p was identified and confirmed as a direct regulator of MALAT1 and it was shown that miR-129-5p mimics were able to restrain the progression of colon cancer cells. In addition, high motility group box protein 1 (HMGB1), was predicted as a mRNA target of miR-129-5p. Furthermore, we found that MALAT1 exerted its biological functions through regulating HMGB1 by sponging miR-129-5p in vitro. Silencing MALAT1 greatly inhibited HMGB1 expression which can be reversed by miR-129-5p inhibitors. It was indicated in our investigation that MALAT1 may serve as a competing endogenous lncRNA (ceRNA) to mediate HMGB1 by sponging miR-129-5p in colon cancer. Taken together, our results indicated that MALAT1/miR-129-5p/HMGB1 axis could be provided as an important prognostic biomarker in colon cancer development.

High-mobility group protein B1 silencing promotes susceptibility of retinoblastoma cells to chemotherapeutic drugs through downregulating nuclear factor-κB

The aim of the present study was to investigate the effects of high-mobility group protein B1 (HMGB1) silencing on the susceptibility of retinoblastoma (RB) cells to chemotherapeutic drugs and the underlying molecular mechanisms. Western blot analysis revealed that vincristine (VCR), etoposide (ETO) and carboplatin (CBP) significantly increased the expression of HMGB1 in Weri‑Rb-1 and Y79 cells compared with the untreated control (P<0.01). siRNA HMGB1 and siRNA negative control (NC) were transfected to Y79 cells by Lipofectamine™ 2000 and, following VCR treatment, the expression of HMGB1 and nuclear factor-κB (NF-κB) was analyzed. siRNA HMGB1 transfection silenced HMGB1 expression. The cytotoxicity of VCR to cells with and without siRNA HMGB1 was investigated by methyl thiazolyl tetrazolium (MTT) assay. siRNA HMGB1 markedly reduced the IC50 value of VCR to RB cells through downregulating the expression of NF-κB, similar to pyrrolidinedithiocarbamate (PDTC). Moreover, following siRNA HMGB1, siRNA NC and ammonium PDTC treatment, the apoptosis of RB cells with VCR incubation was evaluated by Hoechst staining, and the expression of cleaved caspase-3, cleaved poly(ADP-ribose) polymerase (PARP), Beclin 1 and p62 were determined with western blot analysis. The LC3 puncta were determined with immunofluorescence assay. The results demonstrated that VCR treatment significantly downregulated the expression of cleaved caspase-3, cleaved PARP and p62, and upregulated the expression of Beclin 1 in RB cells (P<0.01). Similar to the NF-κB inhibitor PDTC, siRNA HMGB1 significantly promoted apoptosis and suppressed autophagy of VCR‑treated RB cells through reversing the effects of VCR on these signaling molecules (P<0.01). Therefore, HMGB1 silencing promoted the susceptibility of RB cells to chemotherapeutic drugs through downregulating NF-κB.

Polymorphisms of the receptor for advanced glycation end products and glyoxalase I and long-term outcome in patients with breast cancer

Receptor for advanced glycation end products and glyoxalase I metabolizing advanced glycation end product precursors may play important role in the pathogenesis and progression of cancer. Potential relation between soluble forms of receptor for advanced glycation end products (sRAGE), receptor for advanced glycation end products, glyoxalase I polymorphisms, and long-term outcome (median follow-up of 10.3 years) was studied in 116 patients with breast cancer. Gly82Ser and 2184 A/G RAGE polymorphisms were related to the mortality due to the breast cancer and -419 A/C glyoxalase I polymorphism was related to the overall mortality of the patients suggesting their role not only in the risk of breast cancer but also in the outcome of patients with breast cancer.

High ASMA+ Fibroblasts and Low Cytoplasmic HMGB1+ Breast Cancer Cells Predict Poor Prognosis

INTRODUCTION

The influence of cancer-associated fibroblasts (CAFs) and high mobility group box 1 (HMGB1) has been recognized in several cancers, although their roles in breast cancer are unclear. The present study aimed to determine the levels and prognostic significance of α-smooth muscle actin-positive (ASMA⁺) CAFs, plus HMGB1 and receptor for advanced glycation end products (RAGE) in cancer cells.

MATERIALS AND METHODS

A total of 127 breast samples, including 96 malignant and 31 benign, were examined for ASMA, HMGB1, and RAGE by immunohistochemistry. The χ² test and Fisher's exact test were used to test the association of each protein with clinicopathologic parameters. The Kaplan-Meier method or log-rank test and Cox regression were used for survival analysis.

RESULTS

ASMA⁺ fibroblast infiltration was significantly increased in the tumor stroma compared with that in benign breast tissue. The levels of cytoplasmic HMGB1 and RAGE were significantly greater in the breast cancer tissue than in the benign breast tissues. High ASMA expression correlated significantly with large tumor size, clinical stage III-IV, and angiolymphatic and perinodal invasion. In contrast, increased cytoplasmic HMGB1 correlated significantly with small tumor size, pT stage, early clinical stage, luminal subtype (but not triple-negative subtype), and estrogen receptor and progesterone receptor expression. The levels of ASMA (hazard ratio, 14.162; P = .010) and tumor cytoplasmic HMGB1 (hazard ratio, 0.221; P = .005) could serve as independent prognostic markers for metastatic relapse in breast cancer patients. The ASMA-high/HMGB1-low profile provided the most reliable prediction of metastatic relapse.

CONCLUSION

We present for the first time, to the best of our knowledge, the potential clinical implications of the combined assessment of ASMA⁺ fibroblasts and cytoplasmic HMGB1 in breast cancer.

PREDICTIVE CIRCULATING MARKERS FOR ANTHRACYCLINE CHEMOTHERAPY IN NON-METASTATIC BREAST CANCER

Anthracyclines are used in breast cancer both in early and advanced stages and their recommendation together with taxanes, either concurrently or sequentially, is debatable and individualized by phenotype. Circulating biomarkers have already been introduced in clinical practice for metastatic disease monitoring. We questioned whether it might be a role for these markers in neoadjuvant and adjuvant settings too and a general review was conducted. CK18 and CTC were found predictive for anthracycline related response in preoperative setting. Soluble E-cadherin is promising, a retrospective analysis showing a direct correlation with clinical response. CEA, CA 15-3 and HER2 ECD are not of interest for their predictive role.

Combined evaluation of LC3B puncta and HMGB1 expression predicts residual risk of relapse after adjuvant chemotherapy in breast cancer

In spite of adjuvant chemotherapy, a significant fraction of patients with localized breast cancer (BC) relapse after optimal treatment. We determined the occurrence of cytoplasmic MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3B)-positive puncta, as well as the presence of nuclear HMGB1 (high mobility group box 1) in cancer cells within surgical BC specimens by immunohistochemistry, first in a test cohort (152 patients) and then in a validation cohort of localized BC patients who all received adjuvant anthracycline-based chemotherapy (1646 patients). Cytoplasmic LC3B(+) puncta inversely correlated with the intensity of SQSTM1 staining, suggesting that a high percentage cells of LC3B(+) puncta reflects increased autophagic flux. After setting optimal thresholds in the test cohort, cytoplasmic LC3B(+) puncta and nuclear HMGB1 were scored as positive in 27.2% and 28.6% of the tumors, respectively, in the validation cohort, while 8.7% were considered as double positive. LC3B(+) puncta or HMGB1 expression alone did not constitute independent prognostic factors for metastasis-free survival (MFS) in multivariate analyses. However, the combined positivity for LC3B(+) puncta and nuclear HMGB1 constituted an independent prognostic factor significantly associated with prolonged MFS (hazard ratio: 0.49 95% confidence interval [0.26-0.89]; P = 0.02), and improved breast cancer specific survival (hazard ratio: 0.21 95% confidence interval [0.05-0.85]; P = 0.029). Subgroup analyses revealed that within patients with poor-prognosis BC, HMGB1(+) LC3B(+) double-positive tumors had a better prognosis than BC that lacked one or both of these markers. Altogether, these results suggest that the combined positivity for LC3B(+) puncta and nuclear HMGB1 is a positive predictor for longer BC survival.

Prognostic value of HMGB1 in early breast cancer patients under neoadjuvant chemotherapy

The response to neoadjuvant chemotherapy in breast cancer patients is usually assessed by pCR and RCB score. However, the prognostic value of these parameters is still in discussion. We showed recently that an epirubicin/docetaxel therapy is associated with an increase in the cell death marker high‐mobility group box 1 protein (HMGB1) in the circulation. Here, we investigate whether this increase correlates with the long‐term outcome. Thirty‐six early breast cancer patients under neoadjuvant epirubicin/docetaxel combination chemotherapy were included in this study. To determine the immediate effect of this treatment on HMGB1, we collected blood samples before and 24–96 h after the initial dose. This time course was then compared to the 5‐year follow‐up of the patients. HMGB1 levels varied before chemotherapy between 4.1 and 11.3 ng/mL and reacted differently in response to therapy. Some patients showed an increase while others did not show any changes. Therefore, we subdivided the patient collective into two groups: patients with an at least 1.1 ng/mL increase in HMGB1 and patients with smaller changes. The disease‐free survival was longer in the HMGB1 increase group (56.2 months vs. 46.6 months), but this difference did not reach significance. The overall survival (OS) was significantly better in patients with an increase in HMGB1 (log rank P = 0.021). These data suggest that an immediate increase in HMGB1 levels correlates with improved outcome in early breast cancer patients receiving neoadjuvant chemotherapy, and may be a valuable complementary biomarker for early estimation of prognosis.

The implication and potential applications of high-mobility group box 1 protein in breast cancer

High-mobility group box 1 protein (HMGB1) is a highly conserved, non-histone and ubiquitous chromosomal protein found enriched in active chromatin forming part of the high mobility group family of proteins and is encoded by the HMGB1 gene (13q12) in human beings. It has various intranuclear and extracellular functions. It plays an important role in the pathogenesis of many diseases including cancer. In 2012, there was approximately 1.67 million new breast cancer cases diagnosed which makes it the second most frequent cancer in the world after lung cancer (25% of all cancers) and the commonest cancer among women. Both pre-clinical and clinical studies have suggested that HMGB1 might be a useful target in the management of breast cancer. This review summarises the structure and functions of HMGB1 and its dual role in carcinogenesis both as a pro-tumorigenic and anti-tumorigenic factor. It also sums up evidence from in vitro and in vivo studies using breast cancer cell lines and samples which demonstrate its influence in radiotherapy, chemotherapy and hormonal therapy in breast cancer. It may have particular importance in HER2 positive and metastatic breast cancer. It might pave the way for new breast cancer treatments through development of novel drugs, use of microRNAs (miRNAs), targeting breast cancer stem cells (CSCs) and breast cancer immunotherapy. It may also play a role in determining breast cancer prognosis. Thus HMGB1 may open up novel avenues in breast cancer management.

Genetic predisposition of six well-defined polymorphisms in HMGB1/RAGE pathway to breast cancer in a large Han Chinese population

Breast cancer constitutes an enormous burden in China. A strong familial clustering of breast cancer suggests a genetic component in its carcinogenesis. To examine the genetic predisposition of high mobility group box‐1/receptor for advanced glycation end products (HMGB1/RAGE) pathway to breast cancer, we genotyped six well‐defined polymorphisms in this pathway among 524 breast cancer patients and 518 cancer‐free controls from Heilongjiang province, China. There were no deviations from Hardy–Weinberg equilibrium for all polymorphisms. In single‐locus analysis, the frequency of rs1800624 polymorphism mutant A allele in RAGE gene was significantly higher in patients than in controls (24.52% versus 19.50%, P = 0.006), with the carriers of rs1800624‐A allele being 1.51 times more likely to develop breast cancer relative to those with rs1800624‐GG genotype after adjustment (95% confidence interval or CI: 1.17–1.94, P = 0.001). In HMGB1 gene, haplotype analysis did not reveal any significance, while in RAGE gene, haplotypes C‐T‐A and C‐A‐G (alleles in order of rs1800625, rs18006024, rs2070600) were significantly associated with an increased risk of breast cancer (adjusted OR = 2.72 and 10.35; 95% CI: 1.20–6.18 and 1.58–67.80; P = 0.017 and 0.015 respectively). In further genetic score analysis, per unit and quartile increments of unfavourable alleles were significantly associated with an increased risk of breast cancer after adjustment (odds ratio or OR = 1.20 and 1.26; 95% CI: 1.09–1.32 and 1.12–1.42; P < 0.001 and <0.001 respectively). Our findings altogether demonstrate a significant association between RAGE gene rs1800624 polymorphism and breast cancer risk, and more importantly a cumulative impact of multiple risk associated polymorphisms in HMGB1/RAGE pathway on breast carcinogenesis.

Alarmins and Antitumor Immunity

PURPOSE

Alarmins are constitutively present endogenous molecules that essentially act as early warning signals for the immune system. We provide a brief overview of major alarmins and highlight their roles in tumor immunity.

METHODS

We searched PubMed up to January 10, 2016, using alarmins and/or damage-associated molecular patterns (DAMPs), as key words. We selected and reviewed articles that focused on the discovery and functions of alarmin and their roles in tumor immunity.

FINDINGS

Alarmins are essentially endogenous immunostimulatory DAMP molecules that are exposed in response to danger (eg, infection or tissue injury) as a result of degranulation, cell death, or induction. They are sensed by chemotactic receptors and pattern recognition receptors to induce immune responses by promoting the recruitment and activation of leukocytes, particularly antigen-presenting cells.

IMPLICATIONS

Accumulating data suggest that certain alarmins, High-mobility group nucleosome-binding protein 1 (HMGN1) in particular, contribute to the generation of antitumor immunity. Some alarmins can also be used as cancer biomarkers. Therefore, alarmins can potentially be applied for our fight against cancers.

Cytoplasmic expression of high mobility group B1 (HMGB1) is associated with tumor-infiltrating lymphocytes (TILs) in breast cancer

High mobility group box 1 (HMGB1) is a prototypic alarmin or damage-associated molecule inducing inflammatory mediator release and immune response. Several studies have revealed the prognostic and predictive importance of tumor-infiltrating lymphocytes (TILs) in breast cancer. The present study analyzed the expression of HMGB1 in each breast cancer subtype and the relationship between the expression level of HMGB1 and pathologic parameters including TILs. Two cohorts were studied: 575 consecutive breast cancer patients who underwent surgery between 1995 and 1998; and 767 triple negative breast cancer (TNBC) patients who underwent surgery between 2004 and 2010. The immunohistochemical expression level of HMGB1 in cytoplasm and nucleus was evaluated using tissue microarrays. High HMGB1 expression in cytoplasm was associated with high histologic grade, pT stage, and abundant TILs in the consecutive breast cancer cohort. Cytoplasmic HMGB1 expression was higher in TNBCs and HER2-positive tumors than in hormone receptor-positive tumors. In the TNBC cohort, high cytoplasmic HMGB1 expression was significantly associated with high histologic grade, abundant TILs, and high numbers of CD8+ cells. However, nuclear HMGB1 expression was not associated with histologic grade or TIL levels. Neither cytoplasmic nor nuclear expression of HMGB1 showed prognostic significance in TNBC. Cytoplasmic HMGB1 expression is associated with TIL levels in breast cancer.

High mobility group B1 and N1 (HMGB1 and HMGN1) are associated with tumor-infiltrating lymphocytes in HER2-positive breast cancers

Although the prognostic and predictive significance of tumor-infiltrating lymphocytes (TILs) in HER2-positive breast cancers has been established, the drivers of TIL influx remain unclear. We tested whether potential triggers for this response could include high mobility group B1 and N1 (HMGB1 and HMGN1) proteins, which are immunogenic damage-associated molecular pattern molecules. We evaluated TILs and the immunohistochemical expression of HMGB1 and HMGN1 in 447 HER2-positive breast cancer tissues. Normal luminal cells exhibited nuclear expression of HMGB1 and HMBN1. The nuclear and cytoplasmic expression levels of HMG proteins showed a significant inverse correlation (rho = -0.150, p = 0.001 for HMGB1; rho = -0.247, p < 0.001 for HMGN1). Low levels of HMGB1 and HMGN1 nuclear expression were identified in 185 (41.4 %) and 208 (46.5 %) cases, respectively. High levels of cytoplasmic HMGB1 and HMGN1 expression were identified in 107 (23.9 %) and 49 (11.0 %) cases, respectively. High cytoplasmic expression of HMG proteins was significantly associated with a high histological grade, high levels of TILs, peritumoral lymphocytic infiltration, and tertiary lymphoid structures in HER2-positive breast cancer tissues. Tumors with low levels of cytoplasmic HMGB1 and HMGN1 showed significantly lower levels of TILs than those with high levels of each or both HMG proteins. However, the nuclear or cytoplasmic expression of either HMG protein was not found to be significantly associated with survival. High levels of cytoplasmic HMGB1 and HMGN1 protein expression correlated with high levels of TILs in HER2-positive breast cancers. The manipulation of HMGB1 and HMGN1 could represent an immunotherapeutic approach to promote TIL influx into a tumor.

Potential role of High mobility group box 1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and is characterized as a typical inflammation-related carcinoma. High mobility group box protein 1 (HMGB1), a non-histone DNA-binding protein, is identified as a potent proinflammatory mediator when presents extracellularly. Recently, a growing body of evidence indicates that HMGB1 plays a potential role in HCC, but many questions remain unanswered about the relationship between HMGB1 and HCC formation and development. This review focuses on the biological effect of HMGB1, and discusses the association of HMGB1 with HCC and potential use of strategies targeting HMGB1 in HCC treatment.

The Role of HMGB1 Signaling Pathway in the Development and Progression of Hepatocellular Carcinoma: A Review

The story of high mobility group protein B1 (HMGB1) in cancer is complicated and the function of HMGB1 in different cancers is uncertain. This review aims to retrieve literature regarding HMGB1 from English electronic resources, analyze and summarize the role of the HMGB1 signaling pathway in hepatocellular carcinoma (HCC), and provide useful information for carcinogenesis and progression of HCC. Results showed that HMGB1 could induce cell proliferation, differentiation, cell death, angiogenesis, metastasis, inflammation, and enhance immunofunction in in vitro and in vivo HCC models. HMGB1 and its downstream receptors RAGE, TLRs and TREM-1 may be potential anticancer targets. In conclusion, HMGB1 plays an important role in oncogenesis and represents a novel therapeutic target, which deserves further study.

Association between intraoperative ventilator settings and plasma levels of soluble receptor for advanced glycation end-products in patients without pre-existing lung injury

BACKGROUND AND OBJECTIVE

The soluble form of the receptor for advanced glycation end-products (sRAGE) is elevated and correlated with severity in patients with acute respiratory distress syndrome (ARDS). The impact of ventilator settings on plasma levels of sRAGE, in patients with or without pre-existing lung injury, remains under-investigated to date. Our objective was to assess the effects of a lung-protective ventilation strategy (combining low tidal volume, positive end-expiratory pressure and recruitment maneuvers), as compared with a non-protective approach (with high tidal volume and zero end-expiratory pressure), on plasma levels of sRAGE in patients without lung injury undergoing major abdominal surgery.

METHODS

Plasma samples were obtained from 95 patients enrolled in a large randomized controlled trial of lung-protective ventilation for major abdominal surgery. Plasma levels of sRAGE were measured in duplicate with an enzyme-linked immunoassay on day 1, immediately after surgery, and on postoperative days 1, 3 and 7.

RESULTS

Early postoperative plasma levels of sRAGE were significantly lower in the lung-protective ventilation group (n = 47) than in the non-protective ventilation group (n = 48) (mean (standard deviation), 1782 (836) vs 2171 (1678) pg/mL, respectively, P = 0.03). Intraoperative changes in plasma sRAGE were associated with postoperative hypoxemia and ARDS.

CONCLUSIONS

A lung-protective ventilation strategy decreased plasma sRAGE in patients without lung injury undergoing major abdominal surgery compared with the patients with non-protective ventilation. This intraoperative decrease could reflect a lesser degree of epithelial injury.

Circulating HMGB1 and RAGE as Clinical Biomarkers in Malignant and Autoimmune Diseases

High molecular group box 1 (HMGB1) is a highly conserved member of the HMG-box-family; abundantly expressed in almost all human cells and released in apoptosis; necrosis or by activated immune cells. Once in the extracellular space, HMGB1 can act as a danger associated molecular pattern (DAMP), thus stimulating or inhibiting certain functions of the immune system; depending on the “combinatorial cocktail” of the surrounding milieu. HMGB1 exerts its various functions through binding to a multitude of membrane-bound receptors such as TLR-2; -4 and -9; IL-1 and RAGE (receptor for advanced glycation end products); partly complex-bound with intracellular fragments like nucleosomes. Soluble RAGE in the extracellular space, however, acts as a decoy receptor by binding to HMGB1 and inhibiting its effects. This review aims to outline today’s knowledge of structure, intra- and extracellular functions including mechanisms of release and finally the clinical relevance of HMGB1 and RAGE as clinical biomarkers in therapy monitoring, prediction and prognosis of malignant and autoimmune disease.

HMGB1 Neutralizing Antibody Attenuates Cardiac Injury and Apoptosis Induced by Hemorrhagic Shock/Resuscitation in Rats

High-mobility group box 1 (HMGB1) and its natural receptor, Toll-like receptor-4 (TLR4), are involved in various infectious or noninfectious diseases including hemorrhagic shock. HMGB1 neutralizing antibody (anti-HMGB1 monoclonal antibody (mAb)) treatment was shown to alleviate ischemia-reperfusion injury effectively. The aim of this study was to explore whether and by what mechanisms anti-HMGB1 mAb attenuates hemorrhagic shock and resuscitation (HS/R)-induced cardiac injury. Employing rat HS/R models, we found that anti-HMGB1 mAb treatment improved HS/R-induced cardiac function deterioration, attenuated cardiac enzyme elevation, improved ATP loss, and protected cardiac tissue. Anti-HMGB1 mAb also inhibited the production of inflammatory factors interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). Moreover, anti-HMGB1 mAb reduced apoptotic responses by suppressing activated caspase-3 and reversing apoptotic gene expression of capase-3, Bax, and Bcl-2 in rat cardiac tissue. Moreover, anti-HMGB1 mAb decreased HS/R-induced HMGB1 and TLR4 expression elevation. We further confirmed that anti-HMGB1 mAb inhibited lipopolysaccharide-activated HGMB1 and TLR4 expression and decreased inflammatory factors IL-1β, IL-6, and TNF-α at the cellular level. It was concluded that anti-HMGB1 mAb treatment protects rats from cardiac injury induced by HS/R, and the beneficial effects may be related to its inhibitory effects on the HMGB1-TLR4 axis.

Combinatorial strategies for the induction of immunogenic cell death

The term "immunogenic cell death" (ICD) is commonly employed to indicate a peculiar instance of regulated cell death (RCD) that engages the adaptive arm of the immune system. The inoculation of cancer cells undergoing ICD into immunocompetent animals elicits a specific immune response associated with the establishment of immunological memory. Only a few agents are intrinsically endowed with the ability to trigger ICD. These include a few chemotherapeutics that are routinely employed in the clinic, like doxorubicin, mitoxantrone, oxaliplatin, and cyclophosphamide, as well as some agents that have not yet been approved for use in humans. Accumulating clinical data indicate that the activation of adaptive immune responses against dying cancer cells is associated with improved disease outcome in patients affected by various neoplasms. Thus, novel therapeutic regimens that trigger ICD are urgently awaited. Here, we discuss current combinatorial approaches to convert otherwise non-immunogenic instances of RCD into bona fide ICD.

Serum HMGB1 is a predictive and prognostic biomarker for oncolytic immunotherapy

With the emergence of effective immunotherapeutics, which nevertheless harbor the potential for toxicity and are expensive to use, biomarkers are urgently needed for identification of cancer patients who respond to treatment. In this clinical-epidemiological study of 202 cancer patients treated with oncolytic adenoviruses, we address the biomarker value of serum high-mobility group box 1 (HMGB1) protein. Overall survival and imaging responses were studied as primary endpoints and adjusted for confounding factors in two multivariate analyses (Cox and logistic regression). Mechanistic studies included assessment of circulating tumor-specific T-cells by ELISPOT, virus replication by quantitative PCR, and inflammatory cytokines by cytometric bead array. Patients with low HMGB1 baseline levels (below median concentration) showed significantly improved survival (p = 0.008, Log-Rank test) and radiological disease control rate (49.2% vs. 30.0%, p = 0.038, χ² test) as compared to high-baseline patients. In multivariate analyses, the low HMGB1 baseline status was a strong prognostic (HR 0.638, 95% CI 0.462–0.881) and the best predictive factor for disease control (OR 2.618, 95% CI 1.004–6.827). Indicative of an immune-mediated mechanism, antitumor T-cell activity in blood and response to immunogenic-transgene coding viruses associated with improved outcome only in HMGB1-low patients. Our results suggest that serum HMGB1 baseline is a useful prognostic and predictive biomarker for oncolytic immunotherapy with adenoviruses, setting the stage for prospective clinical studies.

High mobility group box-1 and its clinical value in breast cancer

BACKGROUND

High mobility group box-1 (HMGB1) is a factor regulating malignant tumorigenesis, proliferation, and metastasis, and is associated with poor clinical pathology in various human cancers. We investigated the differential concentrations of HMGB1 in tissues and sera, and their clinical value for diagnosis in patients with breast cancer, benign breast disease, and healthy individuals.

METHODS

HMGB1 levels in tumor tissues, adjacent normal tissues, and benign breast disease tissues was detected via immunohistochemistry. Serum HMGB1 was measured using an enzyme-linked immunosorbent assay in 56 patients with breast cancer, 25 patients with benign breast disease, and 30 healthy control subjects. The clinicopathological features of the patients were compared. Tissues were evaluated histopathologically by pathologists.

RESULTS

HMGB1 levels in the tissues and sera of patients with breast cancer were significantly higher than those in patients with benign breast disease or normal individuals. The 56 cancer patients were classified as having high tissue HMGB1 levels (n=41) or low tissue HMGB1 levels (n=15), but the corresponsive serum HMGB1 in these two groups was not significantly different. HMGB1 levels in breast cancer tissues significantly correlated with differentiation grade, lymphatic metastasis, and tumor-node-metastasis stage, but not patient age, tumor size, or HER-2/neu expression; no association between serum HMGB1 levels and these clinicopathological parameters was found. The sensitivity and specificity of tissue HMGB1 levels for the diagnosis of breast cancer were 73.21% and 84.00%, respectively, while positive and negative predictive values were 91.11% and 58.33%.

CONCLUSION

HMGB1 might be involved in the development and progression of breast cancer and could be a supportive diagnostic marker for breast cancer. Serum HMGB1 could be a useful serological biomarker for diagnosis and screening of breast cancer.

Cancer-associated fibroblasts induce high mobility group box 1 and contribute to resistance to doxorubicin in breast cancer cells

Background

Cancer-associated fibroblasts and high mobility group box 1 (HMGB1) protein have been suggested to mediate cancer progression and chemotherapy resistance. The role of such fibroblasts in HMGB1 production in breast cancer is unclear. This study aimed to investigate the effects of cancer-associated fibroblasts on HMGB1 expression in breast cancer cells and its role in chemotherapeutic response.

Methods

Breast cancer-associated fibroblasts (BCFs) and non-tumor-associated fibroblasts (NTFs) were isolated from human breast cancers or adjacent normal tissues and established as primary cultures in vitro. After confirmation of the activated status of these fibroblasts, conditioned-media (CM) were collected and applied to MDA-MB-231 human triple negative breast cancer cells. The levels of intracellular and extracellular HMGB1 were measured by real-time PCR and/or Western blot. The response of BCF-CM-pre-treated cancer cells to doxorubicin (Dox) was compared with those pre-treated with NTF-CM or control cultures. The effect of an HMGB1 neutralizing antibody on Dox resistance induced by extracellular HMGB1 from non-viable Dox-treated cancer cells or recombinant HMGB1 was also investigated.

Results

Immunocytochemical analysis revealed that BCFs and NTFs were alpha-smooth muscle actin (ASMA) positive and cytokeratin 19 (CK19) negative cells: a phenotype consistent with that of activated fibroblasts. We confirmed that the CM from BCFs (but not NTFs), could significantly induce breast cancer cell migration. Intracellular HMGB1 expression was induced in BCF-CM-treated breast cancer cells and also in Dox-treated cells. Extracellular HMGB1 was strongly expressed in the CM after Dox-induced MDA-MB-231 cell death and was higher in cells pre-treated with BCF-CM than NTF-CM. Pre-treatment of breast cancer cells with BCF-CM induced a degree of resistance to Dox in accordance with the increased level of secreted HMGB1. Recombinant HMGB1 was shown to increase Dox resistance and this was associated with evidence of autophagy. Anti-HMGB1 neutralizing antibody significantly reduced the effect of extracellular HMGB1 released from dying cancer cells or of recombinant HMGB1 on Dox resistance.

Conclusions

These findings highlight the potential of stromal fibroblasts to contribute to chemoresistance in breast cancer cells in part through fibroblast-induced HMGB1 production.

HMGB1 in health and disease

Complex genetic and physiological variations as well as environmental factors that drive emergence of chromosomal instability, development of unscheduled cell death, skewed differentiation, and altered metabolism are central to the pathogenesis of human diseases and disorders. Understanding the molecular bases for these processes is important for the development of new diagnostic biomarkers, and for identifying new therapeutic targets. In 1973, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and termed high-mobility group (HMG) proteins. The HMG proteins include three superfamilies termed HMGB, HMGN, and HMGA. High-mobility group box 1 (HMGB1), the most abundant and well-studied HMG protein, senses and coordinates the cellular stress response and plays a critical role not only inside of the cell as a DNA chaperone, chromosome guardian, autophagy sustainer, and protector from apoptotic cell death, but also outside the cell as the prototypic damage associated molecular pattern molecule (DAMP). This DAMP, in conjunction with other factors, thus has cytokine, chemokine, and growth factor activity, orchestrating the inflammatory and immune response. All of these characteristics make HMGB1 a critical molecular target in multiple human diseases including infectious diseases, ischemia, immune disorders, neurodegenerative diseases, metabolic disorders, and cancer. Indeed, a number of emergent strategies have been used to inhibit HMGB1 expression, release, and activity in vitro and in vivo. These include antibodies, peptide inhibitors, RNAi, anti-coagulants, endogenous hormones, various chemical compounds, HMGB1-receptor and signaling pathway inhibition, artificial DNAs, physical strategies including vagus nerve stimulation and other surgical approaches. Future work further investigating the details of HMGB1 localization, structure, post-translational modification, and identification of additional partners will undoubtedly uncover additional secrets regarding HMGB1's multiple functions.

Clinical and prognostic significance of high-mobility group box-1 in human gliomas

The objective of this study was to explore the expression and the clinical and prognostic significance of high-mobility group box-1 (HMGB1) in human gliomas. The expression of HMGB1 in 15 samples of normal brain tissue and 65 samples of different-grade glioma tissue was assayed using immunohistochemistry and western blot analysis. The associations between the differences in expression and pathology grades were analyzed statistically. Uni- and multivariate analyses were performed to investigate the prognostic value of HMGB1 expression and its expression levels. The positive rates of HMGB1 expression in normal brain and glioma tissue were 20.0% (3/15) and 76.9% (50/65), respectively. The expression of HMGB1 in glioma tissue was higher than that in normal tissue (P<0.05). The positive rates of HMGB1 expression in low-grade gliomas (LGGs, grades I and II) and high-grade gliomas (HGGs, grades III and IV) were 63.0% (17/27) and 86.8% (33/38), respectively, and the positive rates in HGG were higher than those in LGG (P=0.024). Western blot analysis showed that HMGB1 was also expressed in normal brain tissue. The expression levels in HGG were significantly higher than those in LGG (P<0.001). HMGB1-positive patients had significantly shorter overall survival times compared with HMGB1-negative patients (P=0.026). Increasing levels of HMGB1 expression significantly correlated with reduced survival times when all patients with glioma were considered (P=0.045). In conclusion, HMGB1 positivity and protein expression levels are of significant clinical and prognostic value in human gliomas. Detecting HMGB1 in human gliomas may be useful for assessing the degree of malignancy, and HMGB1 would appear to be a promising target in the clinical management of patients with glioma.

The high-mobility group nucleosome-binding domain 5 is highly expressed in breast cancer and promotes the proliferation and invasion of breast cancer cells

The high-mobility group nucleosome-binding domain 5 (HMGN5) is a member of the high-mobility group proteins family. Previous study found that HMGN5 is required for tumorigenesis in vitro, and aberrations in the expression of HMGN5 were found in human osteosarcoma, prostate cancer, and squamous cell carcinoma. Nevertheless, the role of HMGN5 in breast cancer remains unclear. This study aimed to investigate the expression and clinical significance of HMGN5 in human breast cancer, confirm the oncogenic role of HMGN5, and explore the mechanism by which HMGN5 contributes to invasion and metastasis. HMGN5 expression was detected in breast cancer tissues and corresponding adjacent non-cancerous tissues from 43 patients by immunohistochemistry, and the clinicopathologic characteristics of all patients were also analyzed. Next, knockdown of HMGN5 protein in MDA-MB-231 cells was performed through a small interfering RNA (siRNA) technique, and cell viability, apoptosis, and invasion were detected by cell vitality test, flow cytometry, and transwell assay, respectively. Immunohistostaining showed that HMGN5 were highly expressed in the nucleus in all breast cancer tissues as compared with the adjacent non-cancerous tissues (ANCT;(73.5 ± 11 vs. 31.0 ± 5 %, P < 0.01). HMGN5 expression level was associated with the poorly differentiated tumor cells, lymph node involvement tumor, and T4 staging tumor. Knockdown of HMGN5 inhibited cell growth, suppressed invasion, and increased cell apoptosis in human breast cancer MDA-MB-231 cells. Western blot analysis demonstrated that the expressions of PCNA, connective tissue growth factor (CTGF), and MMP-9 were decreased in human breast MDA-MB-231 cells depleted of HMGN5. In addition, the apoptotic markers (cleaved PARP and cleaved caspase-3) were significantly increased by HMGN5 knockdown, but microtubule-associated protein 1 light chain 3-II/I (LC3-II/I) did not alter. HMGN5 plays an oncogenic role in human breast cancer by inhibiting cell proliferation and invasion, and activating apoptosis, which could be exploited as a target for therapy in human breast cancer.