High-mobility group box 2 is associated with prognosis of glioblastoma by promoting cell viability, invasion, and chemotherapeutic resistance

The role of HMGB2 in the immune response of Nile tilapia (Oreochromis niloticus) to streptococcal infection

High mobility group protein B2 (HMGB2) is an abundant chromatin-associated protein with pivotal roles in transcription, cell proliferation, differentiation, inflammation, and tumorigenesis. However, its immune function in Nile tilapia (Oreochromis niloticus) remains unclear. In this study, we identified a homologue of HMGB2 from Nile tilapia (On-HMGB2) and investigated its functions in the immune response against streptococcus infection. The open reading frame (ORF) of On-HMGB2 spans 642 bp, encoding 213 amino acids, and contains two conserved HMG domains. On-HMGB2 shares over 80 % homology with other fish species and 74%-76 % homology with mammals. On-HMGB2 was widely distributed in various tissues, with its highest transcript levels in the liver and the lowest in the intestine. Knockdown of On-HMGB2 promoted the inflammatory response in Nile tilapia, increased the bacterial load in the tissues, and led to elevated mortality in Nile tilapia following Streptococcus agalactiae infection. Taken together, On-HMGB2 significantly influences the immune system of Nile tilapia in response to streptococcus infection.

Deciphering the roles of the HMGB family in cancer: Insights from subcellular localization dynamics

The high-mobility group box (HMGB) family consists of four DNA-binding proteins that regulate chromatin structure and function. In addition to their intracellular functions, recent studies have revealed their involvement as extracellular damage-associated molecular patterns (DAMPs), contributing to immune responses and tumor development. The HMGB family promotes tumorigenesis by modulating multiple processes including proliferation, metabolic reprogramming, metastasis, immune evasion, and drug resistance. Due to the predominant focus on HMGB1 in the literature, little is known about the remaining members of this family. This review summarizes the structural, distributional, as well as functional similarities and distinctions among members of the HMGB family, followed by a comprehensive exploration of their roles in tumor development. We emphasize the distributional and functional hierarchy of the HMGB family at both the organizational and subcellular levels, with a focus on their relationship with the tumor immune microenvironment (TIME), aiming to prospect potential strategies for anticancer therapy.

HMGB2 is a biomarker associated with poor prognosis promoting radioresistance in glioma by targeting base excision repair pathway

BACKGROUND

High mobility group box 2 (HMGB2) is considered as a biomarker of poor prognosis in various cancers.This study aims to investigate the effect and mechanism of HMGB2 in gliomas.

METHODS

With the glioma related on-line and our local hospital databases, the expression differences of HMGB2,Kaplan-Meier survival analysis and COX regression analysis were performed.The correlation analysis between the clinicopathological features and imaging parameters with the HMGB2 expression had been done. Then GSEA and PPI networks were carried out to find out the most significant pathway. The pathway inhibitor was applied to verify HMGB2's participation. CCK8,EDU assays,γ-H2AX immunofluorescence staining and colony formation assay were conducted to observe effects on glioma cells.

RESULTS

Available datasets showed that HMGB2 was highly expressed in glioma and patients with high expression of HMGB2 had poorer prognosis and molecular characteristics. Protein level evidence of western blot and immunohistochemistry from our center supported the conclusions above. Analysis on imaging features suggested that HMGB2 expression level had an inverse association with ADCmean but positively with the thickness of enhancing margin. Results from GSEA and PPI network analysis exhibited that HMGB2 was involved in base excision repair (BER) signaling pathway. Experimental evidence demonstrated that the overexpression of HMGB2 promoted the proliferation of glioma cells and enhanced the radio-resistance.

CONCLUSIONS

HMGB2 could promote glioma development and enhance the radioresistance of glioma cells, potentially related to the BER pathway, suggesting it may serve as an underlying biomarker for patients with glioma.

HMGB2 Release Promotes Pulmonary Hypertension and Predicts Severity and Mortality of Patients With Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a progressive and life-threatening disease characterized by pulmonary vascular remodeling, which involves aberrant proliferation and apoptosis resistance of the pulmonary arterial smooth muscle cells (PASMCs), resembling the hallmark characteristics of cancer. In cancer, the HMGB2 (high-mobility group box 2) protein promotes the pro-proliferative/antiapoptotic phenotype. However, the function of HMGB2 in PH remains uninvestigated.

METHODS

Smooth muscle cell (SMC)-specific HMGB2 knockout or HMGB2-OE (HMGB2 overexpression) mice and HMGB2 silenced rats were used to establish hypoxia+Su5416 (HySu)-induced PH mouse and monocrotaline-induced PH rat models, respectively. The effects of HMGB2 and its underlying mechanisms were subsequently elucidated using RNA-sequencing and cellular and molecular biology analyses. Serum HMGB2 levels were measured in the controls and patients with pulmonary arterial (PA) hypertension.

RESULTS

HMGB2 expression was markedly increased in the PAs of patients with PA hypertension and PH rodent models and was predominantly localized in PASMCs. SMC-specific HMGB2 deficiency or silencing attenuated PH development and pulmonary vascular remodeling in hypoxia+Su5416-induced mice and monocrotaline-treated rats. SMC-specific HMGB2 overexpression aggravated hypoxia+Su5416-induced PH. HMGB2 knockdown inhibited PASMC proliferation in vitro in response to PDGF-BB (platelet-derived growth factor-BB). In contrast, HMGB2 protein stimulation caused the hyperproliferation of PASMCs. In addition, HMGB2 promoted PASMC proliferation and the development of PH by RAGE (receptor for advanced glycation end products)/FAK (focal adhesion kinase)-mediated Hippo/YAP (yes-associated protein) signaling suppression. Serum HMGB2 levels were significantly increased in patients with PA hypertension, and they correlated with disease severity, predicting worse survival.

CONCLUSIONS

Our findings indicate that targeting HMGB2 might be a novel therapeutic strategy for treating PH. Serum HMGB2 levels could serve as a novel biomarker for diagnosing PA hypertension and determining its prognosis.

Proteomic Analysis of Spatial Heterogeneity Identifies HMGB2 as Putative Biomarker of Tumor Progression in Adult-Type Diffuse Astrocytomas

Although grading is defined by the highest histological grade observed in a glioma, most high-grade gliomas retain areas with histology reminiscent of their low-grade counterparts. We sought to achieve the following: (i) identify proteins and molecular pathways involved in glioma evolution; and (ii) validate the high mobility group protein B2 (HMGB2) as a key player in tumor progression and as a prognostic/predictive biomarker for diffuse astrocytomas. We performed liquid chromatography tandem mass spectrometry (LC-MS/MS) in multiple areas of adult-type astrocytomas and validated our finding in multiplatform-omics studies and high-throughput IHC analysis. LC-MS/MSdetected proteomic signatures characterizing glioma evolution towards higher grades associated with, but not completely dependent, on IDH status. Spatial heterogeneity of diffuse astrocytomas was associated with dysregulation of specific molecular pathways, and HMGB2 was identified as a putative driver of tumor progression, and an early marker of worse overall survival in grades 2 and 3 diffuse gliomas, at least in part regulated by DNA methylation. In grade 4 astrocytomas, HMGB2 expression was strongly associated with proliferative activity and microvascular proliferation. Grounded in proteomic findings, our results showed that HMGB2 expression assessed by IHC detected early signs of tumor progression in grades 2 and 3 astrocytomas, as well as identified GBMs that had a better response to the standard chemoradiation with temozolomide.

Endosome associated trafficking regulator 1 promotes tumor growth and invasion of glioblastoma multiforme via inhibiting TNF signaling pathway

PURPOSE

Endosome associated trafficking regulator 1 (ENTR1) is a novel endosomal protein, which can affect multiple cellular biological behavior by remodeling plasma membrane structures. However, little is known regarding its function and underlying mechanisms in glioblastoma multiforme.

METHODS

Expression profile and clinical signature were obtained from The Public Database of human tumor. Immunohistochemical staining and western blotting assays were used to measure ENTR1 expression level. Human primary GBM tumor cells and human GBM cell lines A172, U87 and U251 were used to clarify the precise role of ENTR1. CCK-8 assays, wound healing and transwell invasion assays were designed to investigate cell viability, invasion and migration of GBM cells, respectively. Underlying molecular mechanisms of ENTR1 were determined via RNA-seq analysis. Tumor formation assay was used to validate the influence of ENTR1 in vivo.

RESULTS

Compared with normal brain tissues, ENTR1 was highly expressed in gliomas and correlated with malignant grades of gliomas and poor overall survival time. The proliferation and invasion of GBM cells could be weaken and the sensitivity to temozolomide (TMZ) chemotherapy increased after knocking down ENTR1. Overexpression of ENTR1 could reverse this effect. RNA-seq analysis showed that tumor necrosis factor (TNF) signaling pathway might be a putative regulatory target of ENTR1. Tumor formation assay validated that ENTR1 was a significant factor in tumor growth.

CONCLUSION

Our results indicated that ENTR1 played an important role in cell proliferation, invasion and chemotherapeutic sensitivity of GBM, suggesting that ENTR1 might be a novel prognostic marker and significant therapeutic target for GBM.

HMGB2 upregulation promotes the progression of hepatocellular carcinoma cells through the activation of ZEB1/vimentin axis

Background

High mobility group box 2 (HMGB2) is abnormally expressed in human cancers and participated in multiple biological behaviors, such as proliferation, invasion and prognosis. However, its role in hepatocellular carcinoma (HCC) is largely unknown.

Methods

In clinical sample analysis, 62 HCC patients were enrolled in this study. The expression of HMGB2 was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical method, clinical prognosis data were analyzed by Kaplan-Meier analysis. In cellular and molecular biology experiments, HMGB2 expression was analyzed in HCC cells. HMGB2 knockdown model was constructed by small interfering RNA (siRNA). Cell counting kit-8 (CCK-8) and cell migration & invasion assay were used to evaluate cell proliferative potential and motility. Recombinant human vimentin protein was used to partially restore the expression and function of vimentin. Western blot and immunochemical staining were performed to detect HMGB2 protein, zinc finger E-box binding homeobox 1 (ZEB1) and vimentin. Flow cytometry analyses were performed to determine the alteration of cell cycle in different groups.

Results

HMGB2 was abnormally overexpressed in HCC. HMGB2 knockdown reduced malignant behaviors especially the proliferative potential and motility of HCC cells. The inhibition of HCC cells proliferation and mobility could be partially restored via treatment with recombinant vimentin protein. Our findings confirmed abnormal activation of HMGB2-ZEB1 vimentin axis facilitates HCC malignant proliferation and motility. The elevated HMGB2 expression in clinical samples was related to postoperative survival time of HCC patients. It indicated HMGB2 promotes the proliferation and motility potential of HCC via HMGB2-ZEB1-vimentin axis activation.

Conclusions

HMGB2 is up-regulated in HCC and affects the malignant transformation by modulating HMGB2-ZEB1-vimentin signaling pathway, which may provide a research basis for evaluating the disease progression and developing clinical treatment strategies of HCC.

Structure and Functions of HMGB2 Protein

High-Mobility Group (HMG) chromosomal proteins are the most numerous nuclear non-histone proteins. HMGB domain proteins are the most abundant and well-studied HMG proteins. They are involved in variety of biological processes. HMGB1 and HMGB2 were the first members of HMGB-family to be discovered and are found in all studied eukaryotes. Despite the high degree of homology, HMGB1 and HMGB2 proteins differ from each other both in structure and functions. In contrast to HMGB2, there is a large pool of works devoted to the HMGB1 protein whose structure-function properties have been described in detail in our previous review in 2020. In this review, we attempted to bring together diverse data about the structure and functions of the HMGB2 protein. The review also describes post-translational modifications of the HMGB2 protein and its role in the development of a number of diseases. Particular attention is paid to its interaction with various targets, including DNA and protein partners. The influence of the level of HMGB2 expression on various processes associated with cell differentiation and aging and its ability to mediate the differentiation of embryonic and adult stem cells are also discussed.

Inflachromene inhibits intimal hyperplasia through the HMGB1/2- regulated TLR4-NF-κB pathway

The contractile-syntheticphenotypicconversion of vascular smooth muscle cells (VSMCs) plays a key role in atherosclerosis, vascular restenosis, and hypertension. Our previous study explored the correlation between high mobility group box protein (HMGB) 1 and HMGB2 and neointimal hyperplasia after vascular injury. In the present study, we explore whether inflachromene (ICM), a novel inhibitor of the expression of both HMGB1 and HMGB2, modulates phenotypic changes in VSMCs and the mechanisms involved. Mice treated with ICM after carotid artery wire injury showed a decrease in excessive neointimal hyperplasia compared with that in the vehicle groups. In cultured VSMCs, pretreatment with ICM suppressed the angiotensin II (Ang II)-induced phenotypic conversion, proliferation, and migration. We discovered that ICM reduced the Ang II-induced upregulation of the expression of HMGB1 and HMGB2 and inhibited their shuttling between the nucleus and the cytosol. Mechanistically, Ang II-treated VSMCs exhibited higher levels of Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) phosphorylation, which were attenuated by ICM. In addition, the NF-κB inhibitor Bay-117082 abolished the recombinant HMGB1-mediated VSMC phenotypic conversion, proliferation, and migration. Furthermore, ICM ameliorated the Ang II-induced increases in NAD[P]H oxidase expression, thereby attenuating the Ang II-induced proliferation and migration. These results reveal that ICM pretreatment attenuates Ang II-induced VSMC dedifferentiation, proliferation, and migration may by regulating the TLR4-NF-kB pathway. Thus, ICM is a potential therapy and preventive treatment for vascular proliferative diseases.

High level of LncRNA MAPKAPK5-AS1 predicts poor prognosis and contributes to the malignant proliferation and EMT of non-small cell lung cancer via sponging miR-490-3p from HMGB2

BACKGROUND

Patients with non-small cell lung cancer (NSCLC) show a low survival rate, owing to the lack of early diagnostic method and high invasiveness. Long non-coding RNA MAPKAPK5-AS1 that regulates tumor genesis and progression through multiple signals, is upregulated and involved in the growth and apoptosis in lung adenocarcinoma (LUAD).

OBJECTIVE

To investigate whether MAPKAPK5-AS1 affected the malignant progression of NSCLC.

METHODS

The levels of MAPKAPK5-AS1, miR-490-3p and HMGB2 in lung cancer were first analyzed through StarBase website, and confirmed by a quantitative reverse transcriptase-PCR (qRT-PCR) assay. The biological functions of NSCLC cells were examined by CCK-8, 5-ethynyl-2'-deoxyuridine (EdU) and flow cytometry assays. The potential binding sequences lncRNA-miRNA and miRNA-mRNA were predicted by StarBase software and verified via dual luciferase reporter experiment. The effects of MAPKAPK5-AS1 on tumor growth were evaluated in a xenografted mice model.

RESULTS

The expression of MAPKAPK5-AS1 was upregulated in tumor tissues from NSCLC patients. Patients with high expression of MAPKAPK5-AS1 had higher tumor size, advanced TNM stage, higher incidence of lymph node and distant metastasis, and shorter overall survival. Knockdown of MAPKAPK5-AS1 inhibited the proliferation, induced apoptosis and blocked epithelial mesenchymal transformation (EMT) of NSCLC cells. Mechanically, MAPKAPK5-AS1 could upregulate the HMGB2 level in NSCLC cells through competitively binding to miR-490-3p. MiR-490-3p inhibitor reversed the roles of MAPKAPK5-AS1 knockdown on tumor cell proliferation, apoptosis and EMT. Also, HMGB2 knockdown suppressed tumor cell malignant phenotypes. Furthermore, interference of MAPKAPK5-AS1 slowed NSCLC tumor growth in vivo.

CONCLUSION

Knockdown of MAPKAPK5-AS1 inhibited the aggressive tumor phenotypes through miR-490-3p/HMGB2 axis in NSCLC. MAPKAPK5-AS1/miR-490-3p/HMGB2 might be potential biomarkers or therapeutic targets for NSCLC.

An Integrated Immune-Related Bioinformatics Analysis in Glioma: Prognostic Signature’s Identification and Multi-Omics Mechanisms’ Exploration

As the traditional treatment for glioma, the most common central nervous system malignancy with poor prognosis, the efficacy of high-intensity surgery combined with radiotherapy and chemotherapy is not satisfactory. The development of individualized scientific treatment strategy urgently requires the guidance of signature with clinical predictive value. In this study, five prognosis-related differentially expressed immune-related genes (PR-DE-IRGs) (CCNA2, HMGB2, CASP3, APOBEC3C, and BMP2) highly associated with glioma were identified for a prognostic model through weighted gene co-expression network analysis, univariate Cox and lasso regression. Kaplan-Meier survival curves, receiver operating characteristic curves and other methods have shown that the model has good performance in predicting the glioma patients’ prognosis. Further combined nomogram provided better predictive performance. The signature’s guiding value in clinical treatment has also been verified by multiple analysis results. We also constructed a comprehensive competing endogenous RNA (ceRNA) regulatory network based on the protective factor BMP2 to further explore its potential role in glioma progression. Numerous immune-related biological functions and pathways were enriched in a high-risk population. Further multi-omics integrative analysis revealed a strong correlation between tumor immunosuppressive environment/IDH1 mutation and signature, suggesting that their cooperation plays an important role in glioma progression.

CircLPAR3 Acts as an Oncogene in Oral Squamous Cell Carcinoma Through Regulating the miR-643/HMGB2 Network

The malignant progression of oral squamous cell carcinoma (OSCC) has been confirmed to be mediated by a variety of factors, including circular RNA (circRNA). However, the role of circLPAR3 in OSCC development is still unclear. 70 paired OSCC tissues and normal control tissues were obtained from 70 OSCC patients. Quantitative real-time PCR was used to detect the expression of circLPAR3, microRNA (miR)-643, and high-mobility group box 2 (HMGB2). Cell proliferation, apoptosis, metastasis and stemness were assessed using cell counting kit 8 assay, colony-formation assay, flow cytometry, transwell assay and sphere formation assay. Marker protein expression and HMGB2 protein expression were determined by western blot analysis. The interaction between miR-643 and circLPAR3 or HMGB2 was confirmed by RNA pull-down assay, dual-luciferase reporter and RIP assay. The role of circLPAR3 in OSCC tumorigenesis was explored by constructing the xenograft models. Our data showed that circLPAR3 was highly expressed in OSCC tissues and cells. CircLPAR3 silencing suppressed OSCC cell proliferation, metastasis and stemness, while promoted apoptosis. On the mechanism, we discovered that circLPAR3 could sponge miR-643 to positive regulate HMGB2. MiR-643 overexpression had an inhibition effect on OSCC progression, and its inhibitor could reverse the negative regulation of circLPAR3 knockdown on OSCC progression. In addition, overexpressed HMGB2 also reversed the suppressive effect of circLPAR3 silencing on OSCC progression. Animal experiments results showed that downregulated circLPAR3 repressed OSCC tumorigenesis in vivo. Taken together, our data showed that circLPAR3 contributed to OSCC malignant progression through regulating the miR-643/HMGB2 axis.

HMGs as rheostats of chromosomal structure and cell proliferation

High mobility group proteins (HMGs) are the most abundant nuclear proteins next to histones and are robustly expressed across tissues and organs. HMGs can uniquely bend or bind distorted DNA, and are central to such processes as transcription, recombination, and DNA repair. However, their dynamic association with chromatin renders capturing HMGs on chromosomes challenging. Recent work has changed this and now implicates these factors in spatial genome organization. Here, I revisit older and review recent literature to describe how HMGs rewire spatial chromatin interactions to sustain homeostasis or promote cellular aging. I propose a 'rheostat' model to explain how HMG-box proteins (HMGBs), and to some extent HMG A proteins (HMGAs), may control cellular aging and, likely, cancer progression.

The LncRNA RP11-301G19.1/miR-582-5p/HMGB2 axis modulates the proliferation and apoptosis of multiple myeloma cancer cells via the PI3K/AKT signalling pathway

Long non-coding RNAs (lncRNAs) have recently been reported to act as crucial regulators and prognostic biomarkers of human tumorigenesis. Based on microarray data, RP11-301G19.1 was previously identified as an upregulated lncRNA during B cell development. However, the effect of RP11-301G19.1 on multiple myeloma (MM) cells remains unclear. In the present study, the effects of RP11-301G19.1 on tumour progression were ascertained both in vitro and in vivo. Our results demonstrated that RP11-301G19.1 was upregulated in MM cell lines and that its downregulation inhibited the proliferation and cell cycle progression and promoted the apoptosis of MM cells. Bioinformatic analysis and luciferase reporter assay results revealed that RP11-301G19.1 can upregulate the miR-582-5p-targeted gene HMGB2 as a competing endogenous RNA (ceRNA). Furthermore, Western blot results indicated that RP11-301G19.1 knockdown decreased the levels of PI3K and AKT phosphorylation without affecting their total protein levels. Additionally, in a xenograft model of human MM, RP11-301G19.1 knockdown significantly inhibited tumour growth by downregulating HMGB2. Overall, our data demonstrated that RP11-301G19.1 is involved in MM cell proliferation by sponging miR-582-5p and may serve as a therapeutic target for MM.

High-mobility group box 2 reflects exacerbated disease characteristics and poor prognosis in non-small cell lung cancer patients

BACKGROUND

High-mobility group box 2 (HMGB2) is considered as oncogene in non-small cell lung cancer (NSCLC), while its clinical implication is still unknown. This study aimed to explore the correlation of HMGB2 with clinicopathological characteristics and prognosis in NSCLC patients.

METHODS

A total of 133 NSCLC patients who received radical excision were enrolled. HMGB2 expression in the tumor specimens and paired adjacent tissue specimens was determined by immunohistochemical assay (for protein expression) and reverse transcription quantitative polymerase chain reaction assay (for gene expression), respectively.

RESULTS

HMGB2 protein expression was higher in tumor tissue compared with adjacent tissue, and it could distinguish tumor tissue from adjacent tissue (area under the curve (AUC): 0.775, 95%confidence interval (95%CI): 0.720-0.830). Meanwhile, tumor HMGB2 protein high expression correlated with lymph node (LYN) metastasis and advanced TNM stage. Additionally, tumor HMGB2 protein high expression associated with worse disease-free survival (DFS), while HMGB2 protein expression did not correlate with overall survival (OS). Besides, HMGB2 mRNA expression was raised in tumor tissue compared with adjacent tissue, and it had a good value in differentiating tumor tissue from adjacent tissue (AUC: 0.875, 95% CI: 0.834-0.915). Furthermore, tumor HMGB2 mRNA high expression correlated with higher Eastern Cooperative Oncology Group performance status score, LYN metastasis, and advanced TNM stage. Meanwhile, tumor HMGB2 mRNA high expression associated with shorter DFS and OS.

CONCLUSION

HMGB2 could be a biomarker that reflects disease features and prognosis of NSCLC, which is beneficial to improve clinical efficacy in NSCLC patients.

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.

MicroRNA-127-5p impairs function of granulosa cells via HMGB2 gene in premature ovarian insufficiency

Distinct microRNA (miRNA) profiles have been reported in premature ovarian insufficiency (POI), but their functional relevance in POI is not yet clearly stated. In this study, aberrant expressions of miR-127-5p and high mobility group box 2 (HMGB2) were observed by microarrays in granulosa cells (GCs) from biochemical POI (bPOI) women and further confirmed by a quantitative reverse-transcription polymerase chain reaction. Immortalized human granulosa cell line and mouse primary ovarian GCs were used for functional validation. Orthotopic mouse model was established to examine the role of miR-127-5p in vivo. Finally, the expression of miR-127-5p was measured in the plasma of bPOI women. The receiver operating characteristic curve analysis was performed to determine the indicative role of miR-127-5p for ovarian reserve. Results showed the upregulation of miR-127-5p was identified in GCs from bPOI patients. It inhibited GCs proliferation and impaired DNA damage repair capacity through targeting HMGB2, which was significantly downregulated in GCs from the same cohort of cases. miR-127-5p was confirmed to attenuate DNA repair capability via HMGB2 in mouse ovary in vivo. Intriguingly, the upexpression of miR-127-5p was also detected in plasma of bPOI individuals, suggesting that miR-127-5p could be a promising indicator for bPOI. Taken together, our results discovered the deleterious effects of miR-127-5p on GCs function and its predictive value in POI process. The target gene HMGB2 could be considered as a new candidate for POI. This study highlights the importance of DNA repair capacity for ovarian function and sheds light on the epigenetic mechanism in the pathogenicity of POI.

High mobility group box 2 modulates the progression of osteosarcoma and is related with poor prognosis

Background

Increased expression of high mobility group box 2 (HMGB2) has been reported to promote the progression of several malignancies and be related to poor outcome. However, few studies have explored the relationship between HMGB2 and osteosarcoma. In this study, we aimed to obtain a better understanding of HMGB2 and its function in osteosarcoma.

Methods

Utilizing osteosarcoma paraffin sections and osteosarcoma cell lines, we observed the clinico-pathological relationship of osteosarcoma with HMGB2 expression and investigated the functions of HMGB2 in vitro. The possible pathways and regulation networks in which HMGB2 is involved were further explored through analysis of miRNA, mRNA and lncRNA micro array data sets.

Results

Strong expression of HMGB2 was found to be related with Enneking staging (P=0.002), tumor size (P=0.006), metastasis (P<0.001), and survival (P=0.011) in osteosarcoma. Multivariate analysis revealed that HMGB2 might have independent prognostic value in osteosarcoma (P=0.022). Kaplan-Meier curves and the log-rank test showed that survival time was significantly reduced in OS patients with strong HMGB2 expression (P=0.0056). In vitro experiments showed that HMGB2 overexpression promoted cell proliferation and enhanced the migration and invasion ability of osteosarcoma cells. Gene Ontology (GO) term analysis of osteosarcoma cell lines revealed HMGB2 to have various functions and to be mainly enriched in regulation of cell proliferation, cell death, and DNA binding. A competing endogenous RNA (ceRNA) network of miR-139-5p and six candidate lncRNAs was also suggested as targeting HMGB2 in osteosarcoma.

Conclusions

Our findings suggest that HMGB2 might have various functions in promoting the progression of osteosarcoma and may serve as a new target for osteosarcoma research.

Differential Characteristics of HMGB2 Versus HMGB1 and their Perspectives in Ovary and Prostate Cancer

We have summarized common and differential functions of HMGB1 and HMGB2 proteins with reference to pathological processes, with a special focus on cancer. Currently, several "omic" approaches help us compare the relative expression of these 2 proteins in healthy and cancerous human specimens, as well as in a wide range of cancer-derived cell lines, or in fetal versus adult cells. Molecules that interfere with HMGB1 functions, though through different mechanisms, have been extensively tested as therapeutic agents in animal models in recent years, and their effects are summarized. The review concludes with a discussion on the perspectives of HMGB molecules as targets in prostate and ovarian cancers.

OSgbm: An Online Consensus Survival Analysis Web Server for Glioblastoma

Glioblastoma (GBM) is the most common malignant tumor of the central nervous system. GBM causes poor clinical outcome and high mortality rate, mainly due to the lack of effective targeted therapy and prognostic biomarkers. Here, we developed a user-friendly Online Survival analysis web server for GlioBlastoMa, abbreviated OSgbm, to assess the prognostic value of candidate genes. Currently, OSgbm contains 684 samples with transcriptome profiles and clinical information from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and Chinese Glioma Genome Atlas (CGGA). The survival analysis results can be graphically presented by Kaplan-Meier (KM) plot with Hazard ratio (HR) and log-rank p value. As demonstration, the prognostic value of 51 previously reported survival associated biomarkers, such as PROM1 (HR = 2.4120, p = 0.0071) and CXCR4 (HR = 1.5578, p < 0.001), were confirmed in OSgbm. In summary, OSgbm allows users to evaluate and develop prognostic biomarkers of GBM. The web server of OSgbm is available at http://bioinfo.henu.edu.cn/GBM/GBMList.jsp.

Characterization of HMGB1/2 Interactome in Prostate Cancer by Yeast Two Hybrid Approach: Potential Pathobiological Implications

High mobility group box B (HMGB) proteins are pivotal in the development of cancer. Although the proteomics of prostate cancer (PCa) cells has been reported, the involvement of HMGB proteins and their interactome in PCa is an unexplored field of considerable interest. We describe herein the results of the first HMGB1/HMGB2 interactome approach to PCa. Libraries constructed from the PCa cell line, PC-3, and from patients’ PCa primary tumor have been screened by the yeast 2-hybrid approach (Y2H) using HMGB1 and HMGB2 baits. Functional significance of this PCa HMGB interactome has been validated through expression and prognosis data available on public databases. Copy number alterations (CNA) affecting these newly described HMGB interactome components are more frequent in the most aggressive forms of PCa: those of neuroendocrine origin or castration-resistant PCa. Concordantly, adenocarcinoma PCa samples showing CNA in these genes are also associated with the worse prognosis. These findings open the way to their potential use as discriminatory biomarkers between high and low risk patients. Gene expression of a selected set of these interactome components has been analyzed by qPCR after HMGB1 and HMGB2 silencing. The data show that HMGB1 and HMGB2 control the expression of several of their interactome partners, which might contribute to the orchestrated action of these proteins in PCa

Elevated hsa-miR-590-3p expression down-regulates HMGB2 expression and contributes to the severity of IgA nephropathy

Peripheral blood mononuclear cells (PBMCs) play important roles in the pathogenesis of IgA nephropathy (IgAN). Our study aimed to provide a deep understanding of IgAN and focused on the dysregulation of hsa‐miR‐590‐3p and its target gene HMGB2 in PBMCs. Three gene expression profile datasets (GSE14795, GSE73953 and GSE25590) were downloaded from the GEO database. The DEGs (differentially expressed genes)‐miRNA network that was associated with IgAN was constructed by Cytoscape, and HMGB2 and hsa‐miR‐590‐3p were selected for further exploration. The dual‐luciferase reporter system was utilized to verify their interaction. Then, the expression levels of HMGB2 and hsa‐miR‐590‐3p in PBMCs were detected by qPCR in another cohort, and the correlation of their expression levels with the clinical pathological manifestations and serum Gd‐IgA1(galactose‐deficient IgA1) levels was also investigated. HMGB2 was identified as the target gene of hsa‐miR‐590‐3p. Furtherly, the elderly patients had higher HMGB2 expression levels than the expression levels of the younger patients. As the serum creatinine, serum BUN levels increased, the expression of HMGB2 decreased; Besides, the HMGB2 expression was positively correlated with serum complement 3(C3) levels, and it also had a negative correlation with the diastolic blood pressure, but not reach statistical significance. What is more, both hsa‐miR‐590‐3p and HMGB2 expression had a slight correlation tendency with serum Gd‐IgA1 levels in the whole population. In conclusion, HMGB2, the target gene of hsa‐miR‐590‐3p, was identified to correlate with the severity of IgAN, and this provides more clues for the pathogenesis of IgAN.

MicroRNA-329 upregulation impairs the HMGB2/β-catenin pathway and regulates cell biological behaviors in melanoma

Melanoma is responsible for the majority of deaths caused by skin cancer. Antitumor activity of microRNA-329 (miR-329) has been seen in several human cancers. In this study, we identify whether miR-329 serves as a candidate regulator in melanoma. Melanoma-related differentially expressed genes were screened with its potential molecular mechanism predicted. Melanoma tissues and pigmented nevus tissues were collected, where the levels of miR-329 and high-mobility group box 2 (HMGB2) were determined. To characterize the regulatory role of miR-329 on HMGB2 and the β-catenin pathway in melanoma cell activities, miR-329 mimics, miR-329 inhibitors, and siRNA-HMGB2 were transfected into melanoma cells. Cell viability, migration, invasion, cell cycle, and apoptosis were assessed. miR-329 was predicted to influence melanoma by targeting HMGB2 via the β-catenin pathway. High level of HMGB2 and low miR-329 expression were observed in melanoma tissues. HMGB2 was targeted and negatively regulated by miR-329. In melanoma cells transfected with miR-329 mimics or siRNA-HMGB2, cell proliferation, migration, and invasion were impeded, yet cell cycle arrest and apoptosis were promoted, corresponding to decreased levels of β-catenin, cyclin D1, and vimentin and increased levels of GSK3β and E-cadherin. Collectively, our results show that miR-329 can suppress the melanoma progression by downregulating HMGB2 via the β-catenin pathway.

High-mobility group box 2 promoted proliferation of cervical cancer cells by activating AKT signaling pathway

Cervical cancer is one of the leading killers for female worldwide. Nevertheless, the less knowledge of molecular mechanism for cervical cancer limited the improvement of treatment effects. High-mobility group box 2 (HMGB2) belongs to the HMGB family, which could play diverse roles in cell proliferation. This work mainly aimed to study the functions of HMGB2 on cervical cancer cells proliferation. HMGB2 was highly expressed in cervical cancer tissue. The results of real-time polymerase chain reaction and Western blot analysis showed that HMGB2 was expressed in all the five cervical cancer cells (HeLa, CaSki, SiHa, C-33A, and C4-1 cells). In addition, HMGB2 overexpression obviously improved cell viability and promoted cell cycle progression, which suggested that HMGB2 could promote proliferation of cervical cancer cells. Moreover, HMGB2 overexpression increased the level of p-AKT and reduced the levels of p21 and p27. However, HMGB2 downregulation had contrary influences on cell proliferation, cell cycle distribution and the levels of p-AKT, p21, and p27. Notably, LY294002, as an inhibitor of AKT signaling pathway, could significantly weaken the effects of HMGB2 overexpression, which indicated that HMGB2 might promote cell proliferation by activating AKT signaling pathway. Therefore, HMGB2 was hopeful to be a candidate as a new biomarker and therapy target for cervical cancer.

Oncogenic KSHV-encoded interferon regulatory factor upregulates HMGB2 and CMPK1 expression to promote cell invasion by disrupting a complex lncRNA-OIP5-AS1/miR-218-5p network

Kaposi's sarcoma (KS), a highly disseminated tumor of hyperproliferative spindle endothelial cells, is the most common AIDS-associated malignancy caused by infection of Kaposi's sarcoma-associated herpesvirus (KSHV). KSHV-encoded viral interferon regulatory factor 1 (vIRF1) is a viral oncogene but its role in KSHV-induced tumor invasiveness and motility remains unknown. Here, we report that vIRF1 promotes endothelial cell migration, invasion and proliferation by down-regulating miR-218-5p to relieve its suppression of downstream targets high mobility group box 2 (HMGB2) and cytidine/uridine monophosphate kinase 1 (CMPK1). Mechanistically, vIRF1 inhibits p53 function to increase the expression of DNA methyltransferase 1 (DNMT1) and DNA methylation of the promoter of pre-miR-218-1, a precursor of miR-218-5p, and increases the expression of a long non-coding RNA OIP5 antisense RNA 1 (lnc-OIP5-AS1), which acts as a competing endogenous RNA (ceRNA) of miR-218-5p to inhibit its function and reduce its stability. Moreover, lnc-OIP5-AS1 increases DNA methylation of the pre-miR-218-1 promoter. Finally, deletion of vIRF1 from the KSHV genome reduces the level of lnc-OIP5-AS1, increases the level of miR-218-5p, and inhibits KSHV-induced invasion. Together, these results define a novel complex lnc-OIP5-AS1/miR-218-5p network hijacked by vIRF1 to promote invasiveness and motility of KSHV-induced tumors.

HMGB2 promotes the malignancy of human gastric cancer and indicates poor survival outcome

HMGB2 is an important protein in carcinogenesis. However, little is known about the specific role of HMGB2 in gastric cancer. In the present study, HMGB2 expression was evaluated in 198 primary gastric cancer tissues and their adjacent nontumor controls. The correlation between HMGB2 expression and clinico-pathological features and survival was assessed. The effect of HMGB2 on cell proliferation, invasion, and glycolysis was examined in vitro. The expression of HMGB2 was significantly increased in human gastric cancer when compared with nontumor tissues (P < .001). High HMGB2 expression correlated with large tumor size (P = .001), advanced T stage (P = .007), and presence of lymph node metastasis (P = .004). Moreover, high HMGB2 expression was validated as an independent prognostic factor in both univariate and multivariate analyses (P < .05). Experimentally, silencing HMGB2 expression by stable transfected shRNA significantly decreased the proliferation, invasion, and glycolysis of gastric cancer cells. In conclusion, HMGB2 is a novel prognostic biomarker for survival in gastric cancer, and knockdown HMGB2 expression in gastric cancer cells attenuated proliferation and invasion, and impaired glycolysis in gastric cancer cells. Hence, HMGB2 may serve as a new biomarker and a potential therapeutic target in gastric cancer.

Early detection of prostate carcinogens by immunohistochemistry of HMGB2

Screening prostatic carcinogens is time-consuming due to the time needed to induce preneoplastic and neoplastic lesions. To overcome this, we investigated alternative molecular markers for detection of prostatic carcinogens in a short period in rats. After treatment with 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), expression of high-mobility group protein B2 (HMGB2) was up-regulated in rat ventral prostate. To evaluate the applicability of HMGB2 in the early detection of carcinogenicity of chemicals using animal models, we examined HMGB2 expression in prostate of rats. Six-week-old male F344 rats were gavaged for four weeks with a total of eight individual chemicals, divided into two categories based on prostate carcinogenicity. Animals were sacrificed at the end of the study and HMGB2 immunohistochemistry was performed. HMGB2 expression in least one prostate lobe was significantly increased by all four prostate carcinogens compared with the controls. In contrast, the four chemicals that were not carcinogenic in the prostate did not cause HMGB2 up-regulation. Additionally, high HMGB2 expression in neoplastic lesions in both rat and human was detected. Therefore HMGB2 expression may be a good screening tool for the identification of potential of prostate carcinogens.

High-performance reoxygenation from PLGA-PEG/PFOB emulsions: a feedback relationship between ROS and HIF-1α

Background

Hypoxemia is one of the most common pathological processes in various clinical diseases.

Methods

A novel emulsion of poly(lactide-co-glycolide)-poly(ethylene glycol)/perfluorooctyl bromide has been developed to improve arterial hypoxemia through pulmonary drug delivery. Hypoxia-reoxygenation experiment was used to investigate the ability of the emulsion to supply oxygen and the saline lavage acute lung injury model was established to evaluate oxygen supply of the emulsion.

Results

It has been demonstrated that an apparent increase has been detected in the cytotoxicity test of the emulsion, indicating its lower cell toxicity. A hypoxia-reoxygenation experiment uncovered the fact that notable cell growth was observed after reoxygenation with poly(lactide-co-glycolide)-poly(ethylene glycol)/perfluorooctyl bromide emulsion because of the ability of the emulsion to supply oxygen adequately and reasonably. Moreover, the level of intracellular reactive oxygen species was significantly enhanced during hypoxia, which further influenced the concentration and activity of hypoxia-inducible factor-1α (HIF-1α). Furthermore, the upregulated expression of HIF-1α during hypoxia has verified that certain emulsions can increase HIF-1α content and relieve hypoxia, which further indicates HIF-1α plays an essential role in improving cell viability. Afterwards, the saline lavage acute lung injury model was established to evaluate oxygen supply of the emulsion and the result shows considerable improvement of lung ventilation of rabbits.

Conclusion

We recommend that the feedback relationship between reactive oxygen species and HIF-1 plays an essential role in improving cell viability. It is anticipated that the emulsion will be applied in the field of alleviating hypoxemia.

High mobility group protein A2 overexpression indicates poor prognosis for cancer patients: a meta-analysis

Overexpression of the high mobility group protein A2 (HMGA2), an architectural transcription factor, has been linked to poor prognosis in many malignancies, although this remains controversial. Herein, we conducted a meta-analysis to investigate whether HMGA2 has prognostic value, and evaluated the association between HMGA2 and clinicopathologic factors in malignancies. A total of 29 studies involving 4114 patients were included in this meta-analysis. The pooled results demonstrated that elevated HMGA2 predicted a poor overall survival (OS) (hazard ratio [HR] = 1.82; 95% confidence interval [CI] = 1.62-2.05; P < 0.001) and disease-free survival/progression-free survival/recurrence-free survival (HR = 1.94; 95% CI = 1.27-2.98; P = 0.002). Subgroup analysis conducted by study region, sample size, detection method, and analysis method indicated that HMGA2 overexpression correlated with poor OS. Furthermore, HMGA2 overexpression was found to be linked to poor OS in various cancers except ovarian cancer (pooled HR = 1.14; 95% CI = 0.62-2.09; P = 0.673). High HMGA2 expression level also correlated with advanced TNM stage (OR = 2.44; 95% CI =1.87-3.2; P < 0.001), lymphovascular invasion (OR = 2.46, 95% CI = 1.67-3.64; P < 0.001), distant metastasis (OR = 2.66; 95% CI =1.51-4.69; P < 0.001), and lymph node metastasis (OR = 1.83; 95% CI =1.27-2.64; P = 0.001). In conclusion, HMGA2 overexpression indicates a worse prognosis and may serve as a prognostic predictor in cancer patients.

Pituitary Tumor Suppression by Combination of Cabergoline and Chloroquine

CONTEXT

The dopamine agonist cabergoline (CAB) has been used widely in the treatment of prolactinomas and other types of pituitary adenomas, but its clinical use is hampered by intolerance in some patients with prolactinoma and lack of effectiveness in other pituitary tumor types. Chloroquine (CQ) is an old drug widely used to treat malaria. Recent studies, including our own, have revealed that CAB and CQ are involved in induction of autophagy and activation of autophagic cell death.

OBJECTIVE

To test whether CAB and CQ can function cooperatively to suppress growth of pituitary adenomas as well as other cancers.

RESULTS

In vitro studies using the rat pituitary tumor cell lines MMQ and GH3, human pituitary tumor cell primary cultures, and several human cancer cell lines showed that CQ enhanced suppression of cell proliferation by CAB. These results were confirmed in in vivo xenograft models in nude mice and estrogen-induced rat prolactinomas. To understand the mechanism of combined CAB and CQ action, we established a low-CAB-dose condition in which CAB was able to induce autophagy but failed to suppress cell growth. Addition of CQ to low-dose CAB blocked normal autophagic cycles and induced apoptosis, evidenced by the further accumulation of p62/caspase-8/LC3-II.

CONCLUSION

The data suggest that combined use of CAB and CQ may increase clinical effectiveness in treatment of human pituitary adenomas, as well as other cancers, making it an attractive option in tumor and cancer therapies.

Downregulation of miR-130a promotes cell growth and epithelial to mesenchymal transition by activating HMGB2 in glioma

Aberrant expression of miR-130a is usually found in cancer studies; however, the role of miR-130a has seldom been reported in glioma. We explored miR-130a's function and the underlying mechanism in glioma. It was found that miR-130a expression was significantly down-regulated in glioma tissues and cell lines. Overexpression of miR-130a decreased glioma cell growth and invasion both in vitro and in vivo. We identified the oncogene HMGB2 as a downstream target of miR-130a by using luciferase and western blot assays. Knockdown of HMGB2 mimicked the effect of miR-130a in glioma cells. Taken together, our study demonstrate that miR-130a may function as a tumor suppressor in glioma and suggest that miR-130a is a potential therapeutic target for glioma patients.

Silencing of high-mobility group box 2 (HMGB2) modulates cisplatin and 5-fluorouracil sensitivity in head and neck squamous cell carcinoma

Dysregulation of protein expression is associated with most diseases including cancer. MS-based proteomic analysis is widely employed as a tool to study protein dysregulation in cancers. Proteins that are differentially expressed in head and neck squamous cell carcinoma (HNSCC) cell lines compared to the normal oral cell line could serve as biomarkers for patient stratification. To understand the proteomic complexity in HNSCC, we carried out iTRAQ-based MS analysis on a panel of HNSCC cell lines in addition to a normal oral keratinocyte cell line. LC-MS/MS analysis of total proteome of the HNSCC cell lines led to the identification of 3263 proteins, of which 185 proteins were overexpressed and 190 proteins were downregulated more than twofold in at least two of the three HNSCC cell lines studied. Among the overexpressed proteins, 23 proteins were related to DNA replication and repair. These included high-mobility group box 2 (HMGB2) protein, which was overexpressed in all three HNSCC lines studied. Overexpression of HMGB2 has been reported in various cancers, yet its role in HNSCC remains unclear. Immunohistochemical labeling of HMGB2 in a panel of HNSCC tumors using tissue microarrays revealed overexpression in 77% (54 of 70) of tumors. The HMGB proteins are known to bind to DNA structure resulting from cisplatin-DNA adducts and affect the chemosensitivity of cells. We observed that siRNA-mediated silencing of HMGB2 increased the sensitivity of the HNSCC cell lines to cisplatin and 5-FU. We hypothesize that targeting HMGB2 could enhance the efficacy of existing chemotherapeutic regimens for treatment of HNSCC. All MS data have been deposited in the ProteomeXchange with identifier PXD000737 (http://proteomecentral.proteomexchange.org/dataset/PXD000737).

Perfluorocarbon-Encapsulated PLGA-PEG Emulsions as Enhancement Agents for Highly Efficient Reoxygenation to Cell and Organism

Perfluorocarbon (PFC), a kind of oxygen carrier, is encapsulated in PLGA-PEG to prepare a PLGA-PEG/PFC emulsion for highly efficient reoxygenation to cell and organism. HCT 116 cells are used as a model cell, whose viability has a significant enhancement after reoxygenation with PLGA-PEG/PFC emulsion because of the sufficient and timely oxygen supply. Meanwhile, hypoxia-reoxygenation injury will happen along with cell hypoxia-reoxygenation treatment, which is reflected by increasing reactive oxygen species (ROS) in cells. However, the integration of intracellular ROS and cell viability implies that the degree of hypoxia-reoxygenation injury is sublethal to HCT116 cells when the concentration of PLGA-PEG/PFC emulsion is lower than 0.2 mg/mL. Furthermore, the change of the expression level of hypoxia-inducible factor-1α (HIF-1α) is similar to that of cell viability during reoxygenation, which suggests that HIF-1α or its downstream proteins may make a significant contribution to cell viability. In vivo oxygen supply is assessed in rats through pulmonary delivery, which shows that PLGA-PEG/PFC emulsion can supply oxygen to rats and improve rats' lung ventilation.

miR-23b-3p regulates the chemoresistance of gastric cancer cells by targeting ATG12 and HMGB2

Chemotherapy is an important treatment modality for gastric cancer (GC); however, it usually fails because of drug resistance, especially multidrug resistance (MDR). Previously, we found a novel subset of MDR-associated microRNAs (miRNAs) through high-throughput functional screening. In this report, we investigated the exact roles and mechanisms of miR-23b-3p in the MDR of GC. Using gain or loss-of-function in in vitro and in vivo experiments, we found that overexpression of miR-23b-3p reversed cancer cell resistance to multiple chemotherapeutics in vitro and sensitize tumors to chemotherapy in vivo. Reporter gene assay and western blot analysis showed that ATG12 and HMGB2 were the direct targets of miR-23b-3p. Meanwhile, ATG12 and HMGB2 were positively associated with the occurrence of autophagy. Reducing the expression of these target genes by siRNA or inhibition of autophagy both sensitized GC cells to chemotherapy. These findings suggest that a miR-23b-3p/ATG12/HMGB2/autophagy-regulatory loop has a critical role in MDR in GC. In addition, miR-23b-3p could be used as a prognostic factor for overall survival in GC. In conclusion, our data demonstrated that miR-23b-3p inhibited autophagy mediated by ATG12 and HMGB2 and sensitized GC cells to chemotherapy, and suggested the potential application of miR-23b-3p in drug resistance prediction and treatment.

Heat Shock Protein 47 Promotes Glioma Angiogenesis

Heat shock protein 47 (HSP47) is a collagen-binding protein, which has been recently found to express in glioma vessels. However, the expression profile of HSP47 in glioma patients and the underlying mechanisms of HSP47 on glioma angiogenesis are not fully explored. In the current study, we found that expression of HSP47 in glioma vessels was correlated with the grades of gliomas. HSP47 knockdown by siRNAs significantly decreased cell viability in vitro and tumor volume in vivo; moreover, it reduced the microvessel density (MVD) by CD31 immunohistochemistry in vivo. HSP47 knockdown significantly inhibited tube formation, invasion and proliferation of human umbilical vein endothelial cells (HUVECs). Furthermore, conditional medium derived from HSP47 knockdown cells significantly inhibited HUVECs tube formation and migration, while it increased chemosensitivity of HUVECs cells to Avastin. Silencing of HSP47 decreased VEGF expression in glioma cells consistently, and reduced glioma vasculature. Furthermore, HSP47 promoted glioma angiogenesis through HIF1α-VEGFR2 signaling. The present study demonstrates that HSP47 promotes glioma angiogenesis and highlights the importance of HSP47 as an attractive therapeutic target of GBM.

Expression and prognostic significance of TCTN1 in human glioblastoma

Background

Glioblastoma (GBM) is the most common and lethal intracranial malignancy in adults, with dismal prognosis despite multimodal therapies. Tectonic family member 1 (TCTN1) is a protein involved in a diverse range of developmental processes, yet its functions in GBM remain unclear. This study aims to investigate expression profile, prognostic value and effects of TCTN1 gene in GBM.

Methods

Protein levels of TCTN1 were assessed by immunohistochemical staining using a tissue microarray constructed by a Chinese cohort of GBM patients (n = 110), and its mRNA expression was also detected in a subset of this cohort. Kaplan-Meier analysis and Cox regression were performed to estimate the prognostic significance of TCTN1. Similar analyses were also conducted in another two independent cohorts: The Cancer Genome Atlas (TCGA) cohort (n = 528) and the Repository for Molecular Brain Neoplasia Data (REMBRANDT) cohort (n = 228). For the TCGA cohort, the relationships between TCTN1 expression, clinical outcome, molecular subtypes and genetic alterations were also analysed. Furthermore, proliferation of TCTN1 overexpressed or silenced GBM cells was determined by CCK-8 assays.

Results

As discovered in three independent cohorts, both mRNA and protein levels of TCTN1 expression were markedly elevated in human GBMs, and higher TCTN1 expression served as an independent prognostic factor predicting poorer prognosis of GBM patients. Additionally, in the TCGA cohort, TCTN1 expression was dramatically decreased in patients within the proneural subtype compared to other subtypes, and significantly influenced by the status of several genetic aberrations such as CDKN2A/B deletion, EGFR amplification, PTEN deletion and TP53 mutation. The prognostic value of TCTN1 was more pronounced in proneural and mesenchymal subtypes, and was also affected by several genetic alterations particularly PTEN deletion. Furthermore, overexpression of TCTN1 significantly promoted proliferation of GBM cells, while its depletion evidently hampered cell growth.

Conclusions

TCTN1 is elevated in human GBMs and predicts poor clinical outcome for GBM patients, which is associated with molecular subtypes and genetic features of GBMs. Additionally, TCTN1 expression impacts GBM cell proliferation. Our results suggest for the first time that TCTN1 may serve as a novel prognostic factor and a potential therapeutic target for GBM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0288-9) contains supplementary material, which is available to authorized users.

Role of glycosyltransferase PomGnT1 in glioblastoma progression

BACKGROUND

Glioblastoma multiforme (GBM) is the most aggressive and invasive brain tumor, for which novel prognostic markers and predictors of therapeutic response are urgently needed. We reported previously that levels of peptide-O-linked mannose β-1,2-N-acetylglucosaminyltransferase 1 (PomGnT1) in glioma specimens correlated with tumor grade. However, the prognostic significance of PomGnT1 in glioma patients and its function in GBM progression remain unknown.

METHODS

Clinical relevance of PomGnT1 in GBM patients' prognosis was analyzed both in a clinically annotated expression dataset of 446 GBM tumor specimens and in 82 GBM tumor samples collected at our institution. The function of PomGnT1 in glioma growth and invasion, and the underlying mechanisms of PomGnT1 regulation were explored in vitro and in vivo.

RESULTS

PomGnT1 expression in GBM tissues was closely associated with poor prognosis in GBM patients. Forced overexpression of PomGnT1 in glioblastoma cells impaired cell adhesion and increased their proliferation and invasion in vitro. Subsequent in vivo experiments showed that overexpression of PomGnT1 promoted tumor growth and shortened the survival time of tumor-bearing mice in an orthotopic model. Conversely, stable short hairpin RNA-mediated knockdown of PomGnT1 expression produced opposite effects both in vitro and in vivo. Mechanistic studies revealed that activation of epidermal growth factor receptor (EGFR) resulted in EGFR/extracellular signal-regulated kinase-dependent upregulation of PomGnT1, downregulation of receptor-type protein tyrosine phosphatase β, and activation of β-catenin pathway signaling.

CONCLUSION

These findings suggest that PomGnT1 promotes GBM progression via activation of β-catenin and may serve as a prognostic factor for glioma patient survival as well as a novel molecular target for anticancer therapy in malignant glioma.

Glioma-associated antigen HEATR1 induces functional cytotoxic T lymphocytes in patients with glioma

A2B5+ glioblastoma (GBM) cells have glioma stem-like cell (GSC) properties that are crucial to chemotherapy resistance and GBM relapse. T-cell-based antigens derived from A2B5+ GBM cells provide important information for immunotherapy. Here, we show that HEAT repeat containing 1 (HEATR1) expression in GBM tissues was significantly higher than that in control brain tissues. Furthermore, HEATR1 expression in A2B5+ U87 cells was higher than that in A2B5-U87 cells (P = 0.016). Six peptides of HEATR1 presented by HLA-A∗02 were selected for testing of their ability to induce T-cell responses in patients with GBM. When peripheral blood mononuclear cells from healthy donors (n = 6) and patients with glioma (n = 33) were stimulated with the peptide mixture, eight patients with malignant gliomas had positive reactivity with a significantly increased number of responding T-cells. The peptides HEATR(1682-690), HEATR(11126-1134), and HEATR(1757-765) had high affinity for binding to HLA-A∗02:01 and a strong capacity to induce CTL response. CTLs against HEATR1 peptides were capable of recognizing and lysing GBM cells and GSCs. These data are the first to demonstrate that HEATR1 could induce specific CTL responses targeting both GBM cells and GSCs, implicating that HEATR1 peptide-based immunotherapy could be a novel promising strategy for treating patients with GBM.