HMGB1: an overview of its versatile roles in the pathogenesis of colorectal cancer

Targeting HMGB1 and Its Interaction with Receptors: Challenges and Future Directions

High mobility group box 1 (HMGB1) is a nonhistone chromatin protein predominantly located in the nucleus. However, under pathological conditions, HMGB1 can translocate from the nucleus to the cytoplasm and subsequently be released into the extracellular space through both active secretion and passive release mechanisms. The distinct cellular locations of HMGB1 facilitate its interaction with various endogenous and exogenous factors, allowing it to perform diverse functions across a range of diseases. This Perspective provides a comprehensive overview of the structure, release mechanisms, and multifaceted roles of HMGB1 in disease contexts. Furthermore, it introduces the development of both small molecule and macromolecule inhibitors targeting HMGB1 and its interaction with receptors. A detailed analysis of the predicted pockets is also presented, aiming to establish a foundation for the future design and development of HMGB1 inhibitors.

A pan-cancer analysis of the oncogenic function of HMGB1 in human tumors

Background

Although high mobility group box protein 1 (HMGB1) has been researched in relation to cancer in many investigations, a thorough investigation of its role in pan-cancer has yet to be conducted. With the objective of bridging this gap, we delved into the functions of HMGB1 in various tumors.

Methods

This investigation employed The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases to examine HMGB1 gene expression differences and correlation with survival across various human tumors. Then, genetic alterations of HMGB1 were analyzed by tool cBioPortal, and immune cell infiltration was assessed. Finally, we gathered clinial samples from 95 patients with various types of solid tumor and performed somatic mutation analysis using panel sequencing. This further highlighted the role of HMGB1 in different solid tumors.

Results

There was a notable elevation of HMGB1 gene expression in tumor tissues as opposed to non-cancerous tissues across the bulk of tumor types. Elevated HMGB1 gene expression had a connection with shorter overall survival, progression-free survival, and disease-free survival in specific tumor types. Genetic alterations of HMGB1 suggested that the amplifications and mutations of HMGB1 may impact the prognosis of breast cancer (BRCA) and liver hepatocellular carcinoma (LIHC). Both BRCA and mesothelioma (MESO) displayed a connection between the infiltration of cancer-associated fibroblasts (CAFs) and HMGB1 gene expression. Moreover, HMGB1 co-expression analysis revealed its association with genes involved in RNA splicing, mRNA processing, and modulation of mRNA metabolic processes. Additionally, a pathway analysis by use of the Kyoto Encyclopedia of Genes and Genomes (KEGG) unveiled that HMGB1 was implicated in the pathogenic mechanisms of "Hepatitis B," "Viral Carcinogenesis," and "Hepatocellular Carcinoma." Based on somatic mutation analysis of 95 patients with different solid tumors, we found that the frequency of HMGB1 mutations was higher in Liver cancer patients compared to other solid tumors. This finding is consistent with our in-silico study results. Additionally, we discovered that the frequency of HMGB1 mutations ranked among the top 20 mutated genes in the 95 patients' data, indicating that HMGB1 plays an important role in the development and prognosis of various solid tumors.

Conclusion

This pan-cancer study of HMGB1 underscores its potential as a signature marker and target for the management of various tumor types.

Glycyrrhizin ameliorates colorectal cancer progression by regulating NHEJ pathway through inhibiting HMGB1-induced DNA damage response

As one of the most common malignancies, colorectal cancer (CRC) usually starts with a benign lesion and accumulates DNA damage as it progresses to full-fledged cancer. Glycyrrhizin (GL) has been found to alleviate tumor growth and inflammation, while the role of GL influences DNA damage response (DDR) in colorectal cancer remains unclear. GL exposure significantly reduced cell colony formation and viability with a concomitant increase in DNA fragmentation in CRC, meanwhile GL induced apoptosis by activating caspase-3. Moreover, GL induced cell cycle arrest in CRC cells at S phase, which was associated with decreased cyclin D1 in vitro. GL treatment significantly ameliorated tumor growth and promoted DDR in vivo. Mechanism analysis revealed that GL significantly downregulated the NHEJ pathway via inhibiting HMGB1. Finally, the expression of HMGB1 was abnormal regulated in CRC tissue than in adjacent normal tissues and associated with TNM stage and overall survival. Our findings indicate that HMGB1 may be a novel therapeutic target in CRC, a result that GL may serve as a promising drug for CRC treatment.

Directing in Vitro Selection towards G-quadruplex-forming Aptamers to Inhibit HMGB1 Pathological Activity

In the search for novel, effective inhibitors of High-Mobility Group Box1 (HMGB1)-a protein involved in various inflammatory and autoimmune diseases as well as in cancer-we herein discovered a set of anti-HMGB1 G-quadruplex(G4)-forming aptamers by using an in vitro selection procedure applied to a doped library of guanine-rich oligonucleotides. The selected DNA sequences were then studied in a pseudo-physiological buffer mimicking the extracellular medium, where HMGB1 exerts its pathological activity, using spectroscopic, electrophoretic, and chromatographic techniques. All the oligonucleotides proved to fold into monomeric G4s and in some cases also dimeric species, stable at physiological temperature. Remarkably, the protein preferentially recognized the sequences forming dimeric parallel G4 structures, as evidenced by a properly designed chemiluminescent binding assay which also highlighted a good selectivity of these aptamers for HMGB1. Moreover, all aptamers showed anti-HMGB1 activity, inhibiting protein-induced cell migration. The acquired data allowed identifying L12 as the best anti-HMGB1 aptamer, featured by high thermal and enzymatic stability, no toxicity at least up to 5 μM concentration on healthy cells, along with potent anti-HMGB1 activity (IC50 ca. 28 nM) and good binding affinity for the protein, thus indicating it as a very promising lead candidate for in vivo studies.

IGF2BP3 prevent HMGB1 mRNA decay in bladder cancer and development

BACKGROUND

IGF2BP3 functions as an RNA-binding protein (RBP) and plays a role in the posttranscriptional control of mRNA localization, stability, and translation. Its dysregulation is frequently associated with tumorigenesis across various cancer types. Nonetheless, our understanding of how the expression of the IGF2BP3 gene is regulated remains limited. The specific functions and underlying mechanisms of IGF2BP3, as well as the potential benefits of targeting it for therapeutic purposes in bladder cancer, are not yet well comprehended.

METHODS

The mRNA and protein expression were examined by RT-qPCR and western blotting, respectively. The methylation level of CpG sites was detected by Bisulfite sequencing PCR (BSP). The regulation of IGF2BP3 expression by miR-320a-3p was analyzed by luciferase reporter assay. The functional role of IGF2BP3 was determined through proliferation, colony formation, wound healing, invasion assays, and xenograft mouse model. The regulation of HMGB1 by IGF2BP3 was investigated by RNA immunoprecipitation (RIP) and mRNA stability assays.

RESULTS

We observed a significant elevation in IGF2BP3 levels within bladder cancer samples, correlating with more advanced stages and grades, as well as an unfavorable prognosis. Subsequent investigations revealed that the upregulation of IGF2BP3 expression is triggered by copy number gain/amplification and promoter hypomethylation in various tumor types, including bladder cancer. Furthermore, miR-320a-3p was identified as another negative regulator in bladder cancer. Functionally, the upregulation of IGF2BP3 expression exacerbated bladder cancer progression, including the proliferation, migration, and invasion of bladder cancer. Conversely, IGF2BP3 silencing produced the opposite effects. Moreover, IGF2BP3 expression positively correlated with inflammation and immune infiltration in bladder cancer. Mechanistically, IGF2BP3 enhanced mRNA stability and promoted the expression of HMGB1 by binding to its mRNA, which is a factor that promotes inflammation and orchestrates tumorigenesis in many cancers. Importantly, pharmacological inhibition of HMGB1 with glycyrrhizin, a specific HMGB1 inhibitor, effectively reversed the cancer-promoting effects of IGF2BP3 overexpression in bladder cancer. Furthermore, the relationship between HMGB1 mRNA and IGF2PB3 is also observed in mammalian embryonic development, with the expression of both genes gradually decreasing as embryonic development progresses.

CONCLUSIONS

Our present study sheds light on the genetic and epigenetic mechanisms governing IGF2BP3 expression, underscoring the critical involvement of the IGF2BP3-HMGB1 axis in driving bladder cancer progression. Additionally, it advocates for the investigation of inhibiting IGF2BP3-HMGB1 as a viable therapeutic approach for treating bladder cancer.

The Role of High Mobility Group Box B-1 in the Prognosis of Colorectal Cancer Based on the Changes in the Intestinal Mucosal Barrier

Background: To investigate the expression of high mobility group box B-1 (HMGB-1) in patients with colorectal cancer (CRC) and its association with clinicopathological features and prognosis in colorectal carcinoma by combining bioinformatics and clinical data analysis, and to clarify the role of HMGB-1. To examine whether HMGB-1 expression is related to the damage of the intestinal mucosal barrier, and then explore the potential HMGB-1-dependent mechanisms affecting the progression of CRC. Methods: CRC datasets of GSE12945, GSE17536, and GSE17537 from the public gene chip database were screened and downloaded. Clinical information and CRC tissue samples from patients with stage I-III CRC from the hospital were collected. Serum samples of patients were applied by enzyme-linked immunosorbent assay on HMGB-1, and were divided into high and low HMGB-1 expression, which was examined by 16S rDNA sequencing. Immunohistochemistry was performed to examine the relationship between the expression of HMGB-1 and tight junction protein, occludin, tumor necrosis factor-α, and interferon-γ. Results: Based on the Cutoff value of 10.24 ng/mL, the CRC patients were divided into high and low expression groups. In the HMGB-1H patient group, the TNM staging, overall survival, disease-free survival, recurrence, and metastasis were inferior to the HMGB-1L group. The results of 16S rDNA sequencing demonstrated that the Providencia genus was found to be enriched in the HMGB-1L group. Immunohistochemical results showed that HMGB-1 expression was negatively correlated with the expression of ZO-1 and occludin (R = 0.035, R = 0.003, P < .05), but was positively correlated with the expression of TNF-α and IFN-γ (R = 0.016, R = 0.001, P < .05). Conclusion: The survival of CRC patients with positive HMGB-1 expression was significantly shortened, which may be related to the decrease of Rovitensis content, the decreased expression of ZO-1 and occludin, and the increased levels of TNF-α and IFN-γ, which in turn damage the intestinal mucosal barrier, leading to the development of CRC.

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.

Single-cell RNA-Seq and bulk RNA-Seq reveal reliable diagnostic and prognostic biomarkers for CRC

PURPOSE

The potential role of epithelium-specific genes through the adenoma-carcinoma sequence in the development of colorectal cancer (CRC) remains unknown. Therefore, we integrated single-cell RNA sequencing and bulk RNA sequencing data to select diagnosis and prognosis biomarkers for CRC.

METHODS

The CRC scRNA-seq dataset was used to describe the cellular landscape of normal intestinal mucosa, adenoma and CRC and to further select epithelium-specific clusters. Differentially expressed genes (DEGs) of epithelium-specific clusters were identified between intestinal lesion and normal mucosa in the scRNA-seq data throughout the adenoma-carcinoma sequence. Diagnostic biomarkers and prognostic biomarker (the risk score) for CRC were selected in the bulk RNA-seq dataset based on DEGs shared by the adenoma epithelium-specific cluster and the CRC epithelium-specific cluster (shared-DEGs).

RESULTS

Among the 1063 shared-DEGs, we selected 38 gene expression biomarkers and 3 methylation biomarkers that had promising diagnostic power in plasma. Multivariate Cox regression identified  174 shared-DEGs as prognostic genes for CRC. We combined 1000 times LASSO-Cox regression and two-way stepwise regression to select 10 prognostic shared-DEGs to construct the risk score in the CRC meta-dataset. In the external validation dataset, the 1- and 5-year AUCs of the risk score were higher than those of stage, the pyroptosis-related genes (PRG) score and the cuproptosis-related genes (CRG) score. In addition, the risk score was closely associated with the immune infiltration of CRC.

CONCLUSION

The combined analysis of the scRNA-seq dataset and the bulk RNA-seq dataset in this study provides reliable biomarkers for the diagnosis and prognosis of CRC.

Cisplatin Dependent Secretion of Immunomodulatory High Mobility Group Box 1 (HMGB1) Protein from Lung Cancer Cells

High mobility group box 1 (HMGB1) is secreted from activated immune cells, necrotic cells, and certain cancers. Previous studies have reported that different patterns of post-translational modification, particularly acetylation and oxidation, mediate HMGB1 release and confer distinct extracellular HMGB1 signaling activity. Here we report that cisplatin but not carboplatin induces secretion of HMGB1 from human A549 non-small cell lung cancer (NSCLC) cells. Cisplatin-mediated HMGB1 secretion was dose-dependent and was regulated by nuclear exportin 1 (XPO1) also known as chromosomal maintenance 1 (CRM1) rather than adenosine diphosphate (ADP)-ribosylation, acetylation, or oxidation. HMGB1, as well as lysine acetylation and cysteine disulfide oxidation of secreted HMGB1, were monitored by sensitive and specific assays using immunoprecipitation, stable isotope dilution, differential alkylation, and nano liquid chromatography parallel reaction monitoring/high-resolution mass spectrometry (nano-LC-PRM/HRMS). A major fraction of the HMGB1 secreted by low-dose cisplatin treatment of A549 NSCLC cells was found to be in the fully reduced form. In contrast, mainly oxidized forms of HMGB1 were secreted by dimethyl sulfoxide (DMSO)-mediated apoptosis. These findings suggest that inhibition of XPO1 could potentiate the anti-tumor activity of cisplatin by increasing the nuclear accumulation of HMGB1 protein, an inhibitor of cisplatin DNA-adduct repair. Furthermore, low-dose cisplatin therapy could modulate the immune response in NSCLC through the established chemokine activity of extracellular reduced HMGB1. This could potentially enhance the efficacy of subsequent immunotherapy treatment.

Ferroptosis-mediated immune responses in cancer

Cell death is a universal biological process in almost every physiological and pathological condition, including development, degeneration, inflammation, and cancer. In addition to apoptosis, increasing numbers of cell death types have been discovered in recent years. The biological significance of cell death has long been a subject of interest and exploration and meaningful discoveries continue to be made. Ferroptosis is a newfound form of programmed cell death and has been implicated intensively in various pathological conditions and cancer therapy. A few studies show that ferroptosis has the direct capacity to kill cancer cells and has a potential antitumor effect. As the rising role of immune cells function in the tumor microenvironment (TME), ferroptosis may have additional impact on the immune cells, though this remains unclear. In this study we focus on the ferroptosis molecular network and the ferroptosis-mediated immune response, mainly in the TME, and put forward novel insights and directions for cancer research in the near future.

Interleukin-1 alpha and high mobility group box-1 secretion in polyinosinic:polycytidylic-induced colorectal cancer cells occur via RIPK1-dependent mechanism and participate in tumourigenesis

Pathogenic infections have significant roles in the pathogenesis of colorectal cancer (CRC). These infections induce the secretion of various damage-associated molecular patterns (DAMPs) including interleukin-1 alpha (IL-1α) and high mobility group box-1 (HMGB1). Despite their implication in CRC pathogenesis, the mechanism(s) that modulate the secretion of IL-1α and HMGB1, along with their roles in promoting CRC tumourigenesis remain poorly understood. To understand the secretory mechanism, HT-29 and SW480 cells were stimulated with infectious mimetics; polyinosinic:polycytidylic acid [Poly(I:C)], lipopolysaccharide (LPS) and pro-inflammatory stimuli; tumour necrosis factor-alpha (TNF-α). IL-1α and HMGB1 secretion levels upon stimulation were determined via ELISA. Mechanism(s) mediating IL-1α and HMGB1 secretion in CRC cells were characterized using pharmacological inhibitors and CRISPR-Cas9 gene editing targeting relevant pathways. Recombinant IL-1α and HMGB1 were utilized to determine their impact in modulating pro-tumourigenic properties of CRC cells. Pharmacological inhibition showed that Poly(I:C)-induced IL-1α secretion was mediated through endoplasmic reticulum (ER) stress and RIPK1 signalling pathway. The secretion of HMGB1 was RIPK1-dependent but independent of ER stress. RIPK1-targeted CRC cell pools exhibited decreased cell viability upon Poly(I:C) stimulation, suggesting a potential role of RIPK1 in CRC cells survival. IL-1α has both growth-promoting capabilities and stimulates the production of pro-metastatic mediators, while HMGB1 only exhibits the latter; with its redox status having influence. We demonstrated a potential role of RIPK1-dependent signalling pathway in mediating the secretion of IL-1α and HMGB1 in CRC cells, which in turn enhances CRC tumorigenesis. RIPK1, IL-1α and HMGB1 may serve as potential therapeutic targets to mitigate CRC progression.

Extra-Cellular Vesicles Derived from Thyroid Cancer Cells Promote the Epithelial to Mesenchymal Transition (EMT) and the Transfer of Malignant Phenotypes through Immune Mediated Mechanisms

Thyroid cancer is the most common endocrine cancer, and its incidence is increasing in many countries around the world. Among thyroid cancers, the papillary thyroid cancer (PTC) histotype is particularly prevalent. A small percentage of papillary tumors is associated with metastases and aggressive behavior due to de-differentiation obtained through the epithelial-mesenchymal transition (EMT) by which epithelial thyroid cells acquire a fibroblast-like morphology, reduce cellular adhesion, increase motility and expression of mesenchymal proteins. The tumor microenvironment plays an important role in promoting an aggressive phenotype through hypoxia and the secretion of HMGB1 and other factors. Hypoxia has been shown to drastically change the tumor cell phenotype and has been associated with increasing metastatic and migratory behavior. Cells transfer information to neighboring cells or distant locations by releasing extracellular membrane vesicles (EVs) that contain key molecules, such as mRNAs, microRNAs (miRNAs), and proteins, that are able to modify protein expression in recipient cells. In this study, we investigated the potential role of EVs released by the anaplastic cancer cell line CAL-62 in inducing a malignant phenotype in a papillary cancer cell line (BCPAP).

Upregulation of HMGB1 in tumor-associated macrophages induced by tumor cell-derived lactate further promotes colorectal cancer progression

BACKGROUND

Lactate accumulation leads to an acidic tumor microenvironment (TME), in turn promoting colorectal cancer (CRC) progression. Tumor-associated macrophages (TAMs) are the predominant cells in TME. This study aimed to reveal the regulation mechanism of CRC cell-derived lactate on TAMs and explore the mechanism underlying lactate accumulation-induced aggravation in CRC.

METHODS

Cell growth and metastasis were evaluated by colony formation, Transwell, and wound healing assays. Western blot and RT-qPCR were applied to determine the protein and mRNA expression. Flow cytometry was used to analyze the polarization state and apoptotic rate of macrophages induced in THP-1 cells. The lactate in the cell supernatant was quantified using an ELISA kit. Immunofluorescence was performed to visualize the location of High Mobility Group Box 1 (HMGB1). H&E and Ki67 staining assays were used to assess tumorigenesis in nude mice bearing ectopic tumors.

RESULTS

Cell growth and metastasis were promoted in the hypoxic CRC cells. The hypoxic cell supernatant stimulated the M2-type polarization of macrophages. The lactate level increased in hypoxic cancer cells. However, the inhibition of lactate using 3-hydroxy-butyrate (3-OBA) reversed the effects of hypoxia. Also, macrophages showed no promoting effect on cancer cell growth and migration in the presence of 3-OBA. HMGB1 was secreted into the extracellular space of lactate-induced macrophages, further enhancing the malignant behaviors of cancer cells. ERK, EMT, and Wnt signaling pathways were activated in cancer cells due to HMGB1 upregulation.

CONCLUSIONS

The lactate metabolized by cancer cells stimulated M2 polarization and HMGB1 secretion by macrophages, aggravating the carcinogenic behaviors of cancer cells.

Immunocyte Derived Exosomes: Insight into the Potential Chemo-immunotherapeutic Nanocarrier Targeting the Tumor Microenvironment

"Cancer" is a dreadful immune-pathological condition that is characterized by anti-inflammatory and tumorigenic responses, elicited by the infiltrating immune cells in the vicinity of an uncontrollably proliferative tumor in the tumor microenvironment (TME). The TME offers a conducive microenvironment that supports cancer cell survival by modulating the host immune defense. Recent advancement in exosomal research has shown exosomes, originating from immune cells as well as the cancer cells, have immense potential for suppressing cancer progression and survival in the TME. Additionally, exosomes, irrespective of their diverse sources, have been reported to be efficient nanocarriers for cancer therapeutics with the ability for targeted delivery due to their biogenic nature, ease of cellular uptake, and scope for functionalization with biomolecules like peptides, aptamers, targeting ligands, etc. Immune cell-derived exosomes per se have been found efficacious against cancer owing to their immune-stimulant properties (in either naive or antigen primed form) even without loading any of cancer therapeutics or targeting ligand conjugation. Nevertheless, exosomes are being primarily explored as nanovesicular carriers for therapeutic molecules with different loading and targeting strategies, and the synergism between immunotherapeutic behavior of exosomes and the anticancer effect of the therapeutic molecules is yet to be explored. Hence, this review focuses specifically on the possible strategies to modulate the immunological nature of the source immune cells to obtain immune stimulant exosomes and bring these into the spotlight as chemo-immunotherapeutic nanovesicles, that can easily target and modulate the TME.

The Features of Checkpoint Receptor—Ligand Interaction in Cancer and the Therapeutic Effectiveness of Their Inhibition

To date, certain problems have been identified in cancer immunotherapy using the inhibition of immune checkpoints (ICs). Despite the excellent effect of cancer therapy in some cases when blocking the PD-L1 (programmed death-ligand 1) ligand and the immune cell receptors PD-1 (programmed cell death protein 1) and CTLA4 (cytotoxic T-lymphocyte-associated protein 4) with antibodies, the proportion of patients responding to such therapy is still far from desirable. This situation has stimulated the exploration of additional receptors and ligands as targets for immunotherapy. In our article, based on the analysis of the available data, the TIM-3 (T-cell immunoglobulin and mucin domain-3), LAG-3 (lymphocyte-activation gene 3), TIGIT (T-cell immunoreceptor with Ig and immunoreceptor tyrosine-based inhibitory motif (ITIM) domains), VISTA (V-domain Ig suppressor of T-cell activation), and BTLA (B- and T-lymphocyte attenuator) receptors and their ligands are comprehensively considered. Data on the relationship between receptor expression and the clinical characteristics of tumors are presented and are analyzed together with the results of preclinical and clinical studies on the therapeutic efficacy of their blocking. Such a comprehensive analysis makes it possible to assess the prospects of receptors of this series as targets for anticancer therapy. The expression of the LAG-3 receptor shows the most unambiguous relationship with the clinical characteristics of cancer. Its inhibition is the most effective of the analyzed series in terms of the antitumor response. The expression of TIGIT and BTLA correlates well with clinical characteristics and demonstrates antitumor efficacy in preclinical and clinical studies, which indicates their high promise as targets for anticancer therapy. At the same time, the relationship of VISTA and TIM-3 expression with the clinical characteristics of the tumor is contradictory, and the results on the antitumor effectiveness of their inhibition are inconsistent.

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.

The role of histone chaperone spty2d1 in human colorectal cancer

Colorectal cancer (CRC) remains a major public health concern, associated with a high rate of morbidity and mortality. Several factors have been implicated in its occurrence and development, which includes histone chaperones. The role of spty2d1 (spt2)-a novel histone chaperone protein-has rarely been investigated in CRC. Therefore, we demonstrated in this study that spt2 undergoes different genetic alterations in colorectal adenocarcinoma datasets and that it was associated with the proliferation of colon carcinoma. Spt2 silencing can reduce the ability of proliferation and increase the rate of apoptosis of LoVo cells. Regarding the overall survival associated with spt2, only the quartile disease-free survival of colon adenocarcinoma (COAD) was found to be statistically significant, while that of rectum adenocarcinoma (READ) was not. The positive (+++) expression of spt2 was correlated with a deeper invasion depth in colorectal adenocarcinoma, and this effect was more pronounced in COAD. These data collectively suggest that spt2 can influence the progression and prognosis in some subtypes of colorectal adenocarcinoma. Therefore, we propose spt2 as a potential target for application in enhancing the overall therapeutic efficacy in some specific subtypes of colorectal adenocarcinoma.

HMGB3 is a Potential Therapeutic Target by Affecting the Migration and Proliferation of Colorectal Cancer

Colorectal cancer is one of the common malignant tumors in the digestive system, with high incidence and mortality rate. Therefore, there is an urgent need to identify and develop new molecular targets for colorectal cancer treatment. Previous studies have pointed out the important role of HMGB3 in tumors, and how it works in colorectal cancer needs to be studied in depth. In this study, we found that HMGB3 was highly expressed in COAD in the cBioPortal and GEPIA2 databases. Kaplan-Meier analysis showed that compared with patients with lower HMGB3 levels, patients with higher HMGB3 levels had poorer OS (p = 0.001). We also found a correlation between HMGB3 expression and immune infiltration of CRC. To investigate the mechanism of HMGB3 knockdown-mediated colorectal cancer inhibition, we detected a downregulation of N-cadherin, Vimentin and β-catenin proteins after knockdown of HMGB3. Taken together, HMGB3 can be an effective target for CRC treatment in the future, and we have reason to believe that HMGB3 will be of greater value in more tumors in the near future.

Cell type-specific response of colon cancer tumor cell lines to oncolytic HSV-1 virotherapy in hypoxia

Background

Novel strategies are required since the hypoxic tumor microenvironment is one of the important impediments for conventional cancer therapy. High mobility group box 1 (HMGB1) protein can block aerobic respiration in cancer cells. We hypothesized that HMGB1could also kill the colorectal cancer cells during hypoxia.

Methods

In this study, we developed oncolytic herpes simplex virus type 1 expressing HMGB1 protein (HSV-HMGB1) and investigated the cytotoxic effect of HSV-HMGB1 and its parental virus (HSV-ble) on three colorectal cancer cells (HCT116, SW480, and HT29) under normoxic (20% oxygen) and hypoxic (1% oxygen) conditions. We further identified potential autophagy- related genes in HT29 cells by retrieving mRNA expression microarray datasets from the Gene Expression Omnibus database. These genes were then detected in HT29 cells infected with HSV-HMGB1 and HSV-ble during normoxia and hypoxia by Real-Time quantitative PCR (qRT-PCR).

Results

The cytotoxic effect of HSV-HMGB1 was significantly higher than that of HSV-ble during normoxia; however, during hypoxia, HSV-HMGB1 enhanced the viability of HT29 cells at MOI 0.1. Analyzing the cell death pathway revealed that HSV-HMGB1 induced autophagy in HT29 cells under hypoxic conditions.

Conclusion

In conclusion, it appears that oncolytic virotherapy is cell context-dependent. Therefore, understanding the cancer cells’ characteristics, microenvironment, and cell signaling are essential to improve the therapeutic strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02564-4.

miR-495-3p depresses cell proliferation and migration by downregulating HMGB1 in colorectal cancer

Background

MicroRNAs play an important role in the genesis and progression of tumours, including colorectal cancer (CRC), which has a high morbidity and mortality rate. In this research, the role of miR-495-3p and HMGB1 in CRC was investigated.

Methods

We performed qRT-PCR to detect the expression of miR-495-3p in colorectal cancer tissues and cell lines. Functional experiments, such as CCK-8, EdU, Transwell and apoptosis assays, were conducted to explore the effects of miR-495-3p on the proliferation, migration and apoptosis of CRC cells in vitro. Then, database prediction, dual-luciferase reporter gene assays and functional experiments verified the role of the miR-495-3p target gene HMGB1 in CRC. Finally, rescue experiments were performed to investigate whether overexpression of HMGB1 could reverse the inhibitory effect of miR-495-3p on CRC cell proliferation in vivo and in vitro.

Results

miR-495-3p was downregulated in colorectal cancer tissues and cell lines, inhibited the proliferation and migration of colorectal cancer cells and promoted cell apoptosis. Database prediction and dual-luciferase reporter gene assays showed that HMGB1 was the downstream target gene of miR-495-3p. We finally demonstrated that miR-495-3p inhibited CRC cell proliferation by targeting HMGB1 in vitro and in vivo.

Conclusion

Our research shows that miR-495-3p inhibits the progression of colorectal cancer by downregulating the expression of HMGB1, which indicates that miR-495-3p may become a potential therapeutic target for colorectal cancer.

Pharmacological Inhibition of HMGB1 Prevents Muscle Wasting

Background: Cachexia is a multifactorial disorder characterized by weight loss and muscle wasting, making up for about 20% of cancer-related death. However, there are no effective drugs to combat cachexia at present.

Methods: In this study, the effect of CT26 exosomes on C2C12 myotubes was observed. We compared serum HMGB1 level in cachexia and non-cachexia colon cancer patients. We further explored HMGB1 expression level in CT26 exosome. We added recombinant HMGB1 to C2C12 myotubes to observe the effects of HMGB1 on C2C12 myotubes and detected the expression level of the muscle atrophy-related proteins. Then, we used the HMGB1 inhibitor glycyrrhizin to reverse the effects of HMGB1 on C2C12 myotubes. Finally, HMGB1 inhibitor glycyrrhizin was utilized to relieve cachexia in CT26 cachexia mouse model.

Results: Exosomes containing HMGB1 led to muscle atrophy with significantly decreased myotube diameter and increased expression of muscle atrophy-related proteins Atrogin1 and MuRF1. Further, we detected that HMGB1 induced the muscle atrophy mainly via TLR4/NF-κB pathway. Administration of the HMGB1 inhibitor glycyrrhizin could relieve muscle wasting in vitro and attenuate the progression of cachexia in vivo.

Conclusion: These findings demonstrate the cachectic role of HMGB1, whether it is soluble form of HMGB1 or secreted from tumor cells as part of exosomes. HMGB1 inhibitor glycyrrhizin might be a promising drug in colon cancer cachexia.

Roles of HMGBs in Prognosis and Immunotherapy: A Pan-Cancer Analysis

Background: High mobility group box (HMGB) proteins are DNA chaperones involved in transcription, DNA repair, and genome stability. Extracellular HMGBs also act as cytokines to promote inflammatory and immune responses. Accumulating evidence has suggested that HMGBs are implicated in cancer pathogenesis; however, their prognostic and immunological values in pan-cancer are not completely clear. Methods: Multiple tools were applied to analyze the expression, genetic alternations, and prognostic and clinicopathological relevance of HMGB in pan-cancer. Correlations between HMGB expression and tumor immune-infiltrating cells (TIICs), immune checkpoint (ICP) expression, microsatellite instability (MSI), and tumor mutational burden (TMB) in pan-cancer were investigated to uncover their interactions with the tumor immune microenvironment (TIME). Gene set enrichment analysis (GSEA) was conducted for correlated genes of HMGBs to expound potential mechanisms. Results: HMGB expression was significantly elevated in various cancers. Both prognostic and clinicopathological significance was observed for HMGB1 in ACC; HMGB2 in ACC, LGG, LIHC, and SKCM; and HMGB3 in ESCA. Prognostic values were also found for HMGB2 in KIRP and MESO and HMGB3 in BRCA, SARC, SKCM, OV, and LAML. The global alternation of HMGBs showed prognostic significance in ACC, KIRC, and UCEC. Furthermore, HMGBs were significantly correlated with TIIC infiltration, ICP expression, MSI, and TMB in various cancers, indicating their regulations on the TIME. Lastly, results of GSEA-illuminated genes positively correlated with HMGBs which were similarly chromosome components participating in DNA activity-associated events. Conclusion: This study demonstrated that HMGBs might be promising predictive biomarkers for the prognosis and immunotherapeutic response, also immunotherapy targets of multiple cancers.

Sodium butyrate ameliorates Schistosoma japonicum-induced liver fibrosis by inhibiting HMGB1 expression

Schistosomiasis is a prevalent zoonotic parasitic disease caused by schistosomes. Its main threat to human health is hepatic granuloma and fibrosis due to worm eggs. Praziquantel remains the first choice for the treatment of schistosomiasis but has limited benefit in treating liver fibrosis. Therefore, the need to develop effective drugs for treating schistosomiasis-induced hepatic fibrosis is urgent. High-mobility group box 1 protein (HMGB1) is a potential immune mediator that is highly associated with the development of some fibrotic diseases and may be involved in the liver pathology of schistosomiasis. We speculated that HMGB1 inhibitors could have an anti-fibrotic effect. Sodium butyrate (SB), a potent inhibitor of HMGB1, has shown anti-inflammatory activity in some animal disease models. In this study, we evaluated the effects of SB on a murine schistosomiasis model. Mice were percutaneously infected with 20 ± 2 cercariae of Schistosoma japonicum. SB (500 mg/kg/day) was administered every 3 days for the entire experiment period. The activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), liver histopathology, HMGB1 expression, and the levels of interferon gamma (IFN-γ), transforming growth factor-β1 (TGF-β1), and interleukin-6 (IL-6) in serum were analyzed. SB reduced hepatic granuloma and fibrosis of schistosomiasis, reflected by the decreased levels of ALT and AST in serum and the reduced expression of pro-inflammatory and fibrogenic cytokines (IFN-γ, TGF-β1, and IL-6). The protective effect could be attributable to the inhibition of the expression of HMGB1 and release by SB.

Neutrophil extracellular traps in gastrointestinal cancer

Gastrointestinal (GI) cancer is a high-risk malignancy and is characterized by high mortality and morbidity worldwide. Neutrophil extracellular traps (NETs), a weblike structure consisting of chromatin DNA with interspersed cytoplasmic and granule proteins, are extruded by activated neutrophils to entrap and kill bacteria and fungi. However, accumulating evidence shows that NETs are related to the progression and metastasis of cancer. In clinical studies, NETs infiltrate primary GI cancer tissues and are even more abundant in metastatic lesions. The quantity of NETs in peripheral blood is revealed to be associated with ascending clinical tumour stages, indicating the role of NETs as a prognostic markers in GI cancer. Moreover, several inhibitors of NETs or NET-related proteins have been discovered and used to exert anti-tumour effects in vitro or in vivo, suggesting that NETs can be regarded as targets in the treatment of GI cancer. In this review, we will focus on the role of NETs in gastric cancer and colorectal cancer, generalizing their effects on tumour-related thrombosis, invasion and metastasis. Recent reports are also listed to show the latest evidences of how NETs affect GI cancer. Additionally, notwithstanding the scarcity of systematic studies elucidating the underlying mechanisms of the interaction between NETs and cancer cells, we highlight the potential importance of NETs as biomarkers and anti-tumour therapeutic targets.

Data Driven Mathematical Model of FOLFIRI Treatment for Colon Cancer

Many colon cancer patients show resistance to their treatments. Therefore, it is important to consider unique characteristic of each tumor to find the best treatment options for each patient. In this study, we develop a data driven mathematical model for interaction between the tumor microenvironment and FOLFIRI drug agents in colon cancer. Patients are divided into five distinct clusters based on their estimated immune cell fractions obtained from their primary tumors' gene expression data. We then analyze the effects of drugs on cancer cells and immune cells in each group, and we observe different responses to the FOLFIRI drugs between patients in different immune groups. For instance, patients in cluster 3 with the highest T-reg/T-helper ratio respond better to the FOLFIRI treatment, while patients in cluster 2 with the lowest T-reg/T-helper ratio resist the treatment. Moreover, we use ROC curve to validate the model using the tumor status of the patients at their follow up, and the model predicts well for the earlier follow up days.

HMGB1 regulates ferroptosis through Nrf2 pathway in mesangial cells in response to high glucose

Ferroptosis, a novel type of programmed cell death, is involved in inflammation and oxidation of various human diseases, including diabetic kidney disease. The present study explored the role of high-mobility group box-1 (HMGB1) on the regulation of ferroptosis in mesangial cells in response to high glucose. Compared with healthy control, levels of serum ferritin, lactate dehydrogenase (LDH), reactive oxygen species (ROS), malonaldehyde (MDA), and HMGB1 were significantly elevated in diabetic nephropathy (DN) patients, accompanied with deregulated ferroptosis-related molecules, including long-chain acyl-CoA synthetase 4 (ACSL4), prostaglandin-endoperoxide synthase 2 (PTGS2), NADPH oxidase 1 (NOX1), and glutathione peroxidase 4 (GPX4). In vitro assay revealed that erastin and high glucose both induced ferroptosis in mesangial cells. Suppression of HMGB1 restored cellular proliferation, prevented ROS and LDH generation, decreased ACSL4, PTGS2, and NOX1, and increased GPX4 levels in mesangial cells. Furthermore, nuclear factor E2-related factor 2 (Nrf2) was decreased in DN patients and high glucose-mediated translocation of HMGB1 in mesangial cells. Knockdown of HMGB1 suppressed high glucose-induced activation of TLR4/NF-κB axis and promoted Nrf2 expression as well as its downstream targets including HO-1, NQO-1, GCLC, and GCLM. Collectively, these findings suggest that HMGB1 regulates glucose-induced ferroptosis via Nrf2 pathway in mesangial cells.

Data Driven Mathematical Model of Colon Cancer Progression

Every colon cancer has its own unique characteristics, and therefore may respond differently to identical treatments. Here, we develop a data driven mathematical model for the interaction network of key components of immune microenvironment in colon cancer. We estimate the relative abundance of each immune cell from gene expression profiles of tumors, and group patients based on their immune patterns. Then we compare the tumor sensitivity and progression in each of these groups of patients, and observe differences in the patterns of tumor growth between the groups. For instance, in tumors with a smaller density of naive macrophages than activated macrophages, a higher activation rate of macrophages leads to an increase in cancer cell density, demonstrating a negative effect of macrophages. Other tumors however, exhibit an opposite trend, showing a positive effect of macrophages in controlling tumor size. Although the results indicate that for all patients the size of the tumor is sensitive to the parameters related to macrophages, such as their activation and death rate, this research demonstrates that no single biomarker could predict the dynamics of tumors.

Long Non-Coding RNA C1QTNF1 Antisense RNA 1 Upregulates Hexokinase 2 by Sponging microRNA-484 to Promote the Malignancy of Colorectal Cancer

Purpose

The long noncoding RNA C1QTNF1 antisense RNA 1 (C1QTNF1-AS1) contributes to hepatocellular carcinoma development. However, its expression and roles in colorectal cancer (CRC) have not been fully explored. Therefore, this study determined the expression and roles of C1QTNF1-AS1 in CRC and elucidated its detailed mechanism of action.

Methods

C1QTNF1-AS1 expression in CRC tissues and cell lines was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We used Cell Counting Kit-8, flow cytometry, cell migration and invasion assays, and a xenograft tumor model to test the effects of C1QTNF1-AS1 on CRC malignancy. The associations among C1QTNF1-AS1, microRNA-484 (miR-484), and hexokinase 2 (HK2) were explored using luciferase reporter assay, RNA immunoprecipitation, RT–qPCR, and Western blotting.

Results

C1QTNF1-AS1 was overexpressed in CRC and related to poor prognosis. C1QTNF1-AS1 interference inhibited CRC cell proliferation, migration, and invasion but induced apoptosis. Furthermore, C1QTNF1-AS1 deficiency impaired tumor growth in vivo. Mechanistically, C1QTNF1-AS1 adsorbed miR-484, thereby increasing the expression of its target HK2. Rescue experiments revealed that the effects of C1QTNF1-AS1 deficiency in CRC cells were reversed by inhibiting miR-484 or upregulating HK2.

Conclusion

C1QTNF1-AS1 drives CRC progression by sponging miR-484 and consequently upregulating HK2. The C1QTNF1-AS1/miR-484/HK2 pathway may serve as a diagnostic and therapeutic target for CRC.

Biological functions and theranostic potential of HMGB family members in human cancers

The high mobility group box (HMGB) protein family consists of four members: HMGB1, 2, 3, and 4. They share similar amino acid sequences and identical functional regions, especially HMGB1, 2, and 3. The homology in structure may lead to similarity in function. In fact, though their targets may be different, they all possess the fundamental function of binding and distorting target DNAs. However, further research confirmed they are distributed differently in tissues and involved in various distinct physiological and pathological cellular processes, including cell proliferation, division, migration, and differentiation. Recently, the roles of HMGB family members in carcinogenesis has been widely investigated; however, systematic discussion on their functions and clinical values in malignant tumors is limited. In this review, we mainly review and summarize recent advances in knowledge of HMGB family members in terms of structure, distribution, biochemical cascades, and specific mechanisms regarding tumor progression. Importantly, the diagnostic, prognostic, and therapeutic value of these proteins in cancers is discussed. Finally, we envisage the orientation and challenges of this field in further studies.

Glycyrrhizin potentially suppresses the inflammatory response in preeclampsia rat model

OBJECTIVE

The expression of high-mobility group box 1 (HMGB1) in trophoblasts is elevated, which contributes to the development of preeclampsia. Thus, this study aimed to investigate the effect of glycyrrhizin, a natural HMGB1 inhibitor, on the development of preeclampsia.

METHODS

Preeclampsia was induced in pregnant Lewis rats through oral administration of L-NAME (50 mg/kg/day) on gestational day (GD) 13-19. Glycyrrhizin (10, 30, or 60 mg/kg/day) was given by oral gavage on GD 10-19. Systolic blood pressure (SBP), diastolic blood pressure (DBP), 24-hour proteinuria, live pup birth ratio, pup weight, pup body length, and placental weight were measured. Also, the expression levels of inflammatory factors (TNF-α, iNOS, IL-1, and IL-6), HMGB1, and TLR4 in the placenta or in the serum were analyzed by enzyme-linked immunosorbent assay, RT-PCR, and Western blot analysis.

RESULTS

Glycyrrhizin significantly reduced the SBP, DBP, and 24-hour proteinuria on GD 16 and 20 in a dose-dependent manner and ameliorated the pregnancy outcomes in preeclampsia rats. The elevated inflammatory molecule levels were markedly decreased by glycyrrhizin not only in the serum but also in the placenta. Moreover, the upregulated HMGB1 and TLR4 expression levels were diminished by glycyrrhizin administration.

CONCLUSION

This study shows that glycyrrhizin could alleviate preeclampsia and the preeclampsia-associated inflammatory reaction, and this effect could be attributed to HMGB1 inhibition.

Subcellular localization of HMGB1 in colorectal cancer impacts on tumor grade and survival prognosis

The high-mobility group box-1 (HMGB1) protein is implicated in the development of various cancers and their proliferation. According to its function, HMGB1 shuttles between the cell nucleus and cytoplasm, assisting with nucleosome stabilization and gene transcription, or localizing in the cell membrane for outgrowth. The clinicopathologic and prognostic significance of these different subcellular locations and their correlation has been unclear in colorectal cancer (CRC). We found significantly higher rates of nuclear HMGB1 expression in CRC and colorectal adenoma tissue samples (84.0% and 92.6%, respectively) than in normal colorectal tissue (15.0%) and a significantly higher rate of positive cytoplasmic HMGB1 expression in CRC tissue (25.2%) compared with colorectal adenoma (11.8%) and normal colorectal tissue (0.0%). Positive cytoplasmic HMGB1 expression was associated with high-grade CRC, a poor prognosis, and was negatively correlated with strongly positive nuclear HMGB1 expression in CRC tissue specimens (r = – 0.377, P = 0.000). CRC patients with strongly positive nuclear HMGB1 expression had a better survival prognosis than other CRC patients. Preventing nuclear plasma translocation of HMGB1 may be a new strategy for CRC management.

Long Noncoding RNA LINC00525 Promotes the Aggressive Phenotype of Chordoma Through Acting as a microRNA-505-3p Sponge and Consequently Raising HMGB1 Expression

Purposes

Long intergenic non-protein coding RNA 525 (LINC00525), a long noncoding RNA, has been implicated in the carcinogenesis and progression of many human cancer types. However, the detailed roles of LINC00525 in chordoma and the underlying mechanisms are not fully understood. Here, we aimed to determine whether LINC00525 could modulate the oncogenicity of chordoma cells and to elucidate in detail the molecular events underlying these tumor-promoting activities.

Methods

Reverse-transcription quantitative polymerase chain reactions were performed to assess LINC00525 expression in chordoma. The effects of LINC00525 silencing on chordoma cell proliferation, apoptosis, migration, and invasiveness in vitro and tumor growth in vivo were respectively tested using CCK-8 assay, flow cytometry, migration and invasion assays, and xenograft experiments.

Results

High LINC00525 expression levels were detected in chordoma tissues. The proliferative, migratory, and invasive abilities of chordoma cells in vitro and their tumor growth in vivo were suppressed by the LINC00525 knockdown, whereas apoptosis was induced by it. Mechanistically, LINC00525 acted as a molecular sponge of microRNA-505-3p (miR-505-3p) and upregulated the expression of high mobility group box 1 (HMGB1), which is directly targeted by miR-505-3p. Rescue assays indicated that increasing the output of miR-505-3p-HMGB1 axis attenuated the effects of LINC00525 depletion on chordoma cells.

Conclusion

LINC00525, a pro-oncogenic long noncoding RNA, promotes chordoma progression by regulating the miR-505-3p-HMGB1 axis. The LINC00525-miR-505-3p-HMGB1 pathway may be a novel therapeutic target in chordoma.

High Mobility Group Box 1 in Human Cancer

High mobility group box 1 (HMGB1) is an extremely versatile protein that is located predominantly in the nucleus of quiescent eukaryotic cells, where it is critically involved in maintaining genomic structure and function. During cellular stress, however, this multifaceted, cytokine-like protein undergoes posttranslational modifications that promote its translocation to the cytosol, from where it is released extracellularly, either actively or passively, according to cell type and stressor. In the extracellular milieu, HMGB1 triggers innate inflammatory responses that may be beneficial or harmful, depending on the magnitude and duration of release of this pro-inflammatory protein at sites of tissue injury. Heightened awareness of the potentially harmful activities of HMGB1, together with a considerable body of innovative, recent research, have revealed that excessive production of HMGB1, resulting from misdirected, chronic inflammatory responses, appears to contribute to all the stages of tumorigenesis. In the setting of established cancers, the production of HMGB1 by tumor cells per se may also exacerbate inflammation-related immunosuppression. These pro-inflammatory mechanisms of HMGB1-orchestrated tumorigenesis, as well as the prognostic potential of detection of elevated expression of this protein in the tumor microenvironment, represent the major thrusts of this review.