HSP47 Promotes Glioblastoma Stemlike Cell Survival by Modulating Tumor Microenvironment Extracellular Matrix through TGF-β Pathway

Hyperthermia for Targeting Cancer and Cancer Stem Cells: Insights from Novel Cellular and Clinical Approaches

The Cellular Heat Shock Response and in particular heat shock protein activation are vital stress reactions observed in both healthy and cancer cells. Hyperthermia (HT) has been proposed for several years as an advancing non-invasive cancer therapy. It selectively targets cancer cells through mechanisms influenced by temperature and temperature variations. This article delves into the impact of HT on cancer cells, especially cancer stem cells (CSCs), essential contributors to cancer recurrence and metastasis. HT has shown promise in eliminating CSCs, sensitizing them to conventional treatments and modulating the tumor microenvironment. The exploration extends to mesenchymal stem cells (MSCs), which exhibit both pro-tumorigenic and anti-tumorigenic effects. HT's potential in recruiting therapeutic MSCs for targeted delivery of antitumoral agents is also discussed. Furthermore, the article introduces Brain Thermodynamics-guided Hyperthermia (BTGH) technology, a breakthrough in temperature control and modulation of heat transfer under different conditions. This non-invasive method leverages the brain-eyelid thermal tunnel (BTT) to monitor and regulate internal brain temperature. BTGH technology, with its precision and noninvasive continuous monitoring capabilities, is under clinical investigation for applications in neurological disorders and cancer. The innovative three-phase approach involves whole-body HT, targeted brain HT, and organ-specific HT. In conclusion, the exploration of localized or whole-body HT offers promising avenues for cancer, psychiatric and neurological diseases. The ongoing clinical investigations and potential applications underscore the significance of understanding and harnessing heat's responses to enhance human health.

Targeting HSP47 for cancer treatment

Heat shock protein 47 (HSP47) serves as an endoplasmic reticulum residing collagen-specific chaperone and plays an important role in collagen biosynthesis and structural assembly. HSP47 is encoded by the SERPINH1 gene, which is located on chromosome 11q13.5, one of the most frequently amplified regions in human cancers. The expression of HSP47 is regulated by multiple cellular factors, including cytokines, transcription factors, microRNAs, and circular RNAs. HSP47 is frequently upregulated in a variety of cancers and plays an important role in tumor progression. HSP47 promotes tumor stemness, angiogenesis, growth, epithelial-mesenchymal transition, and metastatic capacity. HSP47 also regulates the efficacy of tumor therapies, such as chemotherapy, radiotherapy, and immunotherapy. Inhibition of HSP47 expression has antitumor effects, suggesting that targeting HSP47 is a feasible strategy for cancer treatment. In this review, we highlight the function and expression of regulatory mechanisms of HSP47 in cancer progression and point out the potential development of therapeutic strategies in targeting HSP47 in the future.

HSP47 in human diseases: Navigating pathophysiology, diagnosis and therapy

Heat shock protein 47 (HSP47) is a chaperone protein responsible for regulating collagen maturation and transport, directly impacting collagen synthesis levels. Aberrant HSP47 expression or malfunction has been associated with collagen-related disorders, most notably fibrosis. Recent reports have uncovered new functions of HSP47 in various cellular processes. Hsp47 dysregulation in these alternative roles has been linked to various diseases, such as cancer, autoimmune and neurodegenerative disorders, thereby highlighting its potential as both a diagnostic biomarker and a therapeutic target. In this review, we discuss the pathophysiological roles of HSP47 in human diseases, its potential as a diagnostic tool, clinical screening techniques and its role as a target for therapeutic interventions.

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.

NIR-responsive electrospun nanofiber dressing promotes diabetic-infected wound healing with programmed combined temperature-coordinated photothermal therapy

BACKGROUND

Diabetic wounds present significant challenges, specifically in terms of bacterial infection and delayed healing. Therefore, it is crucial to address local bacterial issues and promote accelerated wound healing. In this investigation, we utilized electrospinning to fabricate microgel/nanofiber membranes encapsulating MXene-encapsulated microgels and chitosan/gelatin polymers.

RESULTS

The film dressing facilitates programmed photothermal therapy (PPT) and mild photothermal therapy (MPTT) under near-infrared (NIR), showcasing swift and extensive antibacterial and biofilm-disrupting capabilities. The PPT effect achieves prompt sterilization within 5 min at 52 °C and disperses mature biofilm within 10 min. Concurrently, by adjusting the NIR power to induce local mild heating (42 °C), the dressing stimulates fibroblast proliferation and migration, significantly enhancing vascularization. Moreover, in vivo experimentation successfully validates the film dressing, underscoring its immense potential in addressing the intricacies of diabetic wounds.

CONCLUSIONS

The MXene microgel-loaded nanofiber dressing employs temperature-coordinated photothermal therapy, effectively amalgamating the advantageous features of high-temperature sterilization and low-temperature promotion of wound healing. It exhibits rapid, broad-spectrum antibacterial and biofilm-disrupting capabilities, exceptional biocompatibility, and noteworthy effects on promoting cell proliferation and vascularization. These results affirm the efficacy of our nanofiber dressing, highlighting its significant potential in addressing the challenge of diabetic wounds struggling to heal due to infection.

Tumor Dormancy and Reactivation: The Role of Heat Shock Proteins

Tumors are a heterogeneous group of cell masses originating in various organs or tissues. The cellular composition of the tumor cell mass interacts in an intricate manner, influenced by humoral, genetic, molecular, and tumor microenvironment cues that dictate tumor growth or suppression. As a result, tumors undergo a period of a dormant state before their clinically discernible stage, which surpasses the clinical dormancy threshold. Moreover, as a genetically imprinted strategy, early-seeder cells, a distinct population of tumor cells, break off to dock nearby or extravasate into blood vessels to secondary tissues, where they form disseminated solitary dormant tumor cells with reversible capacity. Among the various mechanisms underlying the dormant tumor mass and dormant tumor cell formation, heat shock proteins (HSPs) might play one of the most important roles in how the dormancy program plays out. It is known that numerous aberrant cellular processes, such as malignant transformation, cancer cell stemness, tumor invasion, metastasis, angiogenesis, and signaling pathway maintenance, are influenced by the HSPs. An accumulating body of knowledge suggests that HSPs may be involved in the angiogenic switch, immune editing, and extracellular matrix (ECM) remodeling cascades, crucial genetically imprinted strategies important to the tumor dormancy initiation and dormancy maintenance program. In this review, we highlight the biological events that orchestrate the dormancy state and the body of work that has been conducted on the dynamics of HSPs in a tumor mass, as well as tumor cell dormancy and reactivation. Additionally, we propose a conceptual framework that could possibly underlie dormant tumor reactivation in metastatic relapse.

Integrative analysis of bulk RNA-seq and scRNA-seq data indicates the prognostic and immunologic values of SERPINH1 in glioma

BACKGROUND

SERPINH1 is abnormally expressed in multiple cancers and is associated with malignant progression. However, few reports detail its role in the etiopathogenesis of glioma. Hence, the aim of this article was to investigate the potential value of SERPINH1 in glioma using an integrative analysis.

METHODS

Data of RNA-seq and scRNA-seq was obtained and evaluated using online databases. The expression of SERPINH1 was confirmed by qRT-PCR and immunohistochemistry. The prognostic value of SERPINH1 was evaluated using univariate and multivariate Cox regression analyses. SERPINH1-related signaling pathways and the interaction of SERPINH1 with immunity were also investigated.

RESULTS

SERPINH1 exhibited a markedly elevated expression in glioma compared to normal brain tissues in the online databases. Similar results were confirmed by qRT-PCR and immunohistochemistry. SERPINH1 was found to be an independent prognosis factor, and high expression of SERPINH1 indicated poor survival. Moreover, a nomogram was constructed to predict prognosis more accurately and intuitively. GSEA analysis showed that SERPINH1 was involved in seven signaling pathways, including JAK-STAT pathway. Further analysis indicated SERPINH1 was significantly associated with immunity, especially in low-grade glioma. Additionally, an examination of scRNA-seq data revealed that SERPINH1 was primarily expressed in T cells of the CD4+ and CD8+ subsets.

CONCLUSIONS

SERPINH1 is a key biomarker of glioma prognosis and is immunologically relevant, which provides additional options for targeted therapy of glioma.

Overcoming Resistance to Temozolomide in Glioblastoma: A Scoping Review of Preclinical and Clinical Data

Glioblastoma (GB) is the most common and most aggressive primary brain tumor in adults, with an overall survival almost 14.6 months. Optimal resection followed by combined temozolomide chemotherapy and radiotherapy, also known as Stupp protocol, remains the standard of treatment; nevertheless, resistance to temozolomide, which can be obtained throughout many molecular pathways, is still an unsurpassed obstacle. Several factors influence the efficacy of temozolomide, including the involvement of other DNA repair systems, aberrant signaling pathways, autophagy, epigenetic modifications, microRNAs, and extracellular vesicle production. The blood-brain barrier, which serves as both a physical and biochemical obstacle, the tumor microenvironment's pro-cancerogenic and immunosuppressive nature, and tumor-specific characteristics such as volume and antigen expression, are the subject of ongoing investigation. In this review, preclinical and clinical data about temozolomide resistance acquisition and possible ways to overcome chemoresistance, or to treat gliomas without restoration of chemosensitinity, are evaluated and presented. The objective is to offer a thorough examination of the clinically significant molecular mechanisms and their intricate interrelationships, with the aim of enhancing understanding to combat resistance to TMZ more effectively.

Biosensor-Enhanced Organ-on-a-Chip Models for Investigating Glioblastoma Tumor Microenvironment Dynamics

Glioblastoma, an aggressive primary brain tumor, poses a significant challenge owing to its dynamic and intricate tumor microenvironment. This review investigates the innovative integration of biosensor-enhanced organ-on-a-chip (OOC) models as a novel strategy for an in-depth exploration of glioblastoma tumor microenvironment dynamics. In recent years, the transformative approach of incorporating biosensors into OOC platforms has enabled real-time monitoring and analysis of cellular behaviors within a controlled microenvironment. Conventional in vitro and in vivo models exhibit inherent limitations in accurately replicating the complex nature of glioblastoma progression. This review addresses the existing research gap by pioneering the integration of biosensor-enhanced OOC models, providing a comprehensive platform for investigating glioblastoma tumor microenvironment dynamics. The applications of this combined approach in studying glioblastoma dynamics are critically scrutinized, emphasizing its potential to bridge the gap between simplistic models and the intricate in vivo conditions. Furthermore, the article discusses the implications of biosensor-enhanced OOC models in elucidating the dynamic features of the tumor microenvironment, encompassing cell migration, proliferation, and interactions. By furnishing real-time insights, these models significantly contribute to unraveling the complex biology of glioblastoma, thereby influencing the development of more accurate diagnostic and therapeutic strategies.

Epigenetic Mechanisms Histone Deacetylase-Dependent Regulate the Glioblastoma Angiogenic Matrisome and Disrupt Endothelial Cell Behavior In Vitro

Glioblastoma (GBM) is the most aggressive brain tumor and different efforts have been employed in the search for new drugs and therapeutic protocols for GBM. Epitranscriptomics has shed light on new druggable Epigenetic therapies specifically designed to modulate GBM biology and behavior such as Histone Deacetylase inhibitors (iHDAC). Although the effects of iHDAC on GBM have been largely explored, there is a lack of information on the underlaying mechanisms HDAC-dependent that modulate the repertoire of GBM secreted molecules focusing on the set of Extracellular Matrix (ECM) associated proteins, the Matrisome, that may impact the surrounding tumor microenvironment. To acquire a better comprehension of the impacts of HDAC activity on the GBM Matrisome, we studied the alterations on the Matrisome-associated ECM regulators, Core Matrisome ECM glycoproteins, ECM-affiliated proteins and Proteoglycans upon HDAC inhibition in vitro as well as their relationship with glioma pathophysiological/clinical features and angiogenesis. For this, U87MG GBM cells were treated for with iHDAC or vehicle (control) and the whole secretome was processed by Mass Spectrometry NANOLC-MS/MS. In silico analyses revealed that proteins associated to the Angiogenic Matrisome (AngioMatrix), including Decorin, ADAM10, ADAM12 and ADAM15 were differentially regulated in iHDAC versus control secretome. Interestingly, genes coding for the Matrisome proteins differentially regulated were found mutated in patients and were correlated to glioma pathophysiological/clinical features. In vitro functional assays, using HBMEC endothelial cells exposed to the secretome of control or iHDAC treated GBM cells, coupled to 2D and 3D GBM cell culture system, showed impaired migratory capacity of endothelial cells and disrupted tubulogenesis in a Fibronectin and VEGF independent fashion. Collectively, our study provides understanding of epigenetic mechanisms HDAC-dependent to key Matrisomal proteins that may contribute to identify new druggable Epigenetic therapies or gliomagenesis biomarkers with relevant implications to improve therapeutic protocols for this malignancy.

Understanding the glioblastoma tumor microenvironment: leveraging the extracellular matrix to increase immunotherapy efficacy

Glioblastoma (GBM) accounts for approximately half of all malignant brain tumors, and it remains lethal with a five-year survival of less than 10%. Despite the immense advancements in the field, it has managed to evade even the most promising therapeutics: immunotherapies. The main reason is the highly spatiotemporally heterogeneous and immunosuppressive GBM tumor microenvironment (TME). Accounting for this complex interplay of TME-driven immunosuppression is key to developing effective therapeutics. This review will explore the immunomodulatory role of the extracellular matrix (ECM) by establishing its contribution to the TME as a key mediator of immune responses in GBM. This relationship will help us elucidate therapeutic targets that can be leveraged to develop and deliver more effective immunotherapies.

Identification of a miRNA multi-targeting therapeutic strategy in glioblastoma

Glioblastoma (GBM) is a deadly and the most common primary brain tumor in adults. Due to their regulation of a high number of mRNA transcripts, microRNAs (miRNAs) are key molecules in the control of biological processes and are thereby promising therapeutic targets for GBM patients. In this regard, we recently reported miRNAs as strong modulators of GBM aggressiveness. Here, using an integrative and comprehensive analysis of the TCGA database and the transcriptome of GBM biopsies, we identified three critical and clinically relevant miRNAs for GBM, miR-17-3p, miR-222, and miR-340. In addition, we showed that the combinatorial modulation of three of these miRNAs efficiently inhibited several biological processes in patient-derived GBM cells of all these three GBM subtypes (Mesenchymal, Proneural, Classical), induced cell death, and delayed tumor growth in a mouse tumor model. Finally, in a doxycycline-inducible model, we observed a significant inhibition of GBM stem cell viability and a significant delay of orthotopic tumor growth. Collectively, our results reveal, for the first time, the potential of miR-17-3p, miR-222 and miR-340 multi-targeting as a promising therapeutic strategy for GBM patients.

Overexpression of heat-shock protein 47 impacts survival of patients with oral squamous cell carcinoma

BACKGROUND

The expression of heat-shock protein 47 (HSP47) has been linked to collagen synthesis control and implicated in fibrotic disorders, but more recent studies have demonstrated its role in solid tumors. In this study, we explored the prognostic impact of HSP47 in oral squamous cell carcinomas (OSCC) and determined the in vitro effects of its loss-of-function on viability, proliferation, migration, invasion, and resistance to cisplatin of OSCC cells.

METHODS

The HSP47 expression in tumor samples was assessed by immunohistochemistry in two independent cohorts totaling 339 patients with OSCC, and protein levels were associated with clinicopathological features and survival outcomes. The OSCC cell lines HSC3 and SCC9 were transduced with lentivirus expressing short hairpin RNA to stably silence HSP47 and used in assays to measure cellular viability, proliferation, migration, and invasion.

RESULTS

HSP47 was overexpressed in OSCC samples, and its overexpression was significantly and independently associated with poor disease-specific survival and shortened disease-free survival in both OSCC cohorts. The knockdown of HSP47 showed no effects on cell viability or cisplatin sensitivity, but impaired significantly proliferation, migration, and invasion of OSCC cells, with stronger effects on SCC9 cells.

CONCLUSION

Our results show a significant prognostic impact of HSP47 overexpression in OSCC and reveal that HSP47 inhibition impairs the proliferation, migration, and invasion of OSCC cells. HSP47 may represent a potential therapeutic target for OSCC.

The Extracellular Matrix in Glioblastomas: A Glance at Its Structural Modifications in Shaping the Tumoral Microenvironment-A Systematic Review

BACKGROUND AND AIM

While many components of the ECM have been isolated and characterized, its modifications in the specific setting of GBMs have only been recently explored in the literature. The aim of this paper is to provide a systematic review on the topic and to assess the ECM's role in shaping tumoral development.

METHODS

An online literature search was launched on PubMed/Medline and Scopus using the research string "((Extracellular matrix OR ECM OR matrix receptor OR matrix proteome) AND (glioblastoma OR GBM) AND (tumor invasion OR tumor infiltration))", and a systematic review was conducted in accordance with the PRISMA-P guidelines.

RESULTS

The search of the literature yielded a total of 693 results. The duplicate records were then removed (n = 13), and the records were excluded via a title and abstract screening; 137 studies were found to be relevant to our research question and were assessed for eligibility. Upon a full-text review, 59 articles were finally included and were summarized as follows based on their focus: (1) proteoglycans; (2) fibrillary proteins, which were further subdivided into the three subcategories of collagen, fibronectin, and laminins; (3) glycoproteins; (4) degradative enzymes; (5) physical forces; (6) and glioma cell and microglia migratory and infiltrative patterns.

CONCLUSIONS

Our systematic review demonstrates that the ECM should not be regarded anymore as a passive scaffold statically contributing to mechanical support in normal and pathological brain tissue but as an active player in tumor-related activity.

Extracellular matrix remodeling in tumor progression and immune escape: from mechanisms to treatments

The malignant tumor is a multi-etiological, systemic and complex disease characterized by uncontrolled cell proliferation and distant metastasis. Anticancer treatments including adjuvant therapies and targeted therapies are effective in eliminating cancer cells but in a limited number of patients. Increasing evidence suggests that the extracellular matrix (ECM) plays an important role in tumor development through changes in macromolecule components, degradation enzymes and stiffness. These variations are under the control of cellular components in tumor tissue via the aberrant activation of signaling pathways, the interaction of the ECM components to multiple surface receptors, and mechanical impact. Additionally, the ECM shaped by cancer regulates immune cells which results in an immune suppressive microenvironment and hinders the efficacy of immunotherapies. Thus, the ECM acts as a barrier to protect cancer from treatments and supports tumor progression. Nevertheless, the profound regulatory network of the ECM remodeling hampers the design of individualized antitumor treatment. Here, we elaborate on the composition of the malignant ECM, and discuss the specific mechanisms of the ECM remodeling. Precisely, we highlight the impact of the ECM remodeling on tumor development, including proliferation, anoikis, metastasis, angiogenesis, lymphangiogenesis, and immune escape. Finally, we emphasize ECM "normalization" as a potential strategy for anti-malignant treatment.

Glioblastoma multiforme: Diagnosis, treatment, and invasion

Glioblastoma multiforme (GBM) is an essentially incurable brain tumor, which has been explored for approximately a century. Nowadays, surgical resection, chemotherapy, and radiation therapy are still the standardized therapeutic options. However, due to the intrinsic invasion and metastasis features and the resistance to chemotherapy, the survival rate of glioblastoma patients remains unsatisfactory. To improve the current situation, much more research is needed to provide comprehensive knowledge of GBM. In this review, we summarize the latest updates on GBM treatment and invasion. Firstly, we review the traditional and emerging therapies that have been used for GBM treatment. Given the limited efficiency of these therapies, we further discuss the role of invasion in GBM recurrence and progression, and present current research progress on the mode and mechanisms of GBM invasion.

Platelets in the tumor microenvironment and their biological effects on cancer hallmarks

The interplay between platelets and tumors has long been studied. It has been widely accepted that platelets could promote tumor metastasis. However, the precise interactions between platelets and tumor cells have not been thoroughly investigated. Although platelets may play complex roles in multiple steps of tumor development, most studies focus on the platelets in the circulation of tumor patients. Platelets in the primary tumor microenvironment, in addition to platelets in the circulation during tumor cell dissemination, have recently been studied. Their effects on tumor biology are gradually figured out. According to updated cancer hallmarks, we reviewed the biological effects of platelets on tumors, including regulating tumor proliferation and growth, promoting cancer invasion and metastasis, inducing vasculature, avoiding immune destruction, and mediating tumor metabolism and inflammation.

Targeting Heat Shock Proteins in Malignant Brain Tumors: From Basic Research to Clinical Trials

Heat shock proteins (HSPs) are conservative and ubiquitous proteins that are expressed both in prokaryotic and eukaryotic organisms and play an important role in cellular homeostasis, including the regulation of proteostasis, apoptosis, autophagy, maintenance of signal pathways, protection from various stresses (e.g., hypoxia, ionizing radiation, etc.). Therefore, HSPs are highly expressed in tumor cells, including malignant brain tumors, where they also associate with cancer cell invasion, metastasis, and resistance to radiochemotherapy. In the current review, we aimed to assess the diagnostic and prognostic values of HSPs expression in CNS malignancies as well as the novel treatment approaches to modulate the chaperone levels through the application of inhibitors (as monotherapy or in combination with other treatment modalities). Indeed, for several proteins (i.e., HSP10, HSPB1, DNAJC10, HSPA7, HSP90), a direct correlation between the protein level expression and poor overall survival prognosis for patients was demonstrated that provides a possibility to employ them as prognostic markers in neuro-oncology. Although small molecular inhibitors for HSPs, particularly for HSP27, HSP70, and HSP90 families, were studied in various solid and hematological malignancies demonstrating therapeutic potential, still their potential was not yet fully explored in CNS tumors. Some newly synthesized agents (e.g., HSP40/DNAJ inhibitors) have not yet been evaluated in GBM. Nevertheless, reported preclinical studies provide evidence and rationale for the application of HSPs inhibitors for targeting brain tumors.

Heat shock proteins: Biological functions, pathological roles, and therapeutic opportunities

The heat shock proteins (HSPs) are ubiquitous and conserved protein families in both prokaryotic and eukaryotic organisms, and they maintain cellular proteostasis and protect cells from stresses. HSP protein families are classified based on their molecular weights, mainly including large HSPs, HSP90, HSP70, HSP60, HSP40, and small HSPs. They function as molecular chaperons in cells and work as an integrated network, participating in the folding of newly synthesized polypeptides, refolding metastable proteins, protein complex assembly, dissociating protein aggregate dissociation, and the degradation of misfolded proteins. In addition to their chaperone functions, they also play important roles in cell signaling transduction, cell cycle, and apoptosis regulation. Therefore, malfunction of HSPs is related with many diseases, including cancers, neurodegeneration, and other diseases. In this review, we describe the current understandings about the molecular mechanisms of the major HSP families including HSP90/HSP70/HSP60/HSP110 and small HSPs, how the HSPs keep the protein proteostasis and response to stresses, and we also discuss their roles in diseases and the recent exploration of HSP related therapy and diagnosis to modulate diseases. These research advances offer new prospects of HSPs as potential targets for therapeutic intervention.

CyPA interacts with SERPINH1 to promote extracellular matrix production and inhibit epithelial-mesenchymal transition of trophoblast via enhancing TGF-β/Smad3 pathway in preeclampsia

We previously reported that cyclophilin A (CyPA) production is upregulated in preeclampsia (PE). Moreover, CyPA is known to induce PE-like features in pregnant mice and impair trophoblast invasiveness. In this study, we further illustrated the role of CyPA in PE. RNA-seq analysis, RT-qPCR, immunohistochemical (IHC) staining, and western blotting of mouse placentae revealed that CyPA increased the levels of extracellular matrix (ECM) proteins, such as collagen I and fibronectin, and activated the TGF-β/Smad3 signaling pathway. Additionally, CyPA inhibited the expression of genes involved in epithelial-mesenchymal transition (EMT) (e.g., E-cadherin, N-cadherin, and vimentin) in mouse placentae. We then constructed stable overexpressing and knock-down CyPA cell models (using HTR8/SVneo cells) to clarify the molecular mechanism. We found that CyPA regulated the levels of ECM-related proteins and the EMT process through the TGF-β/Smad3 pathway. We also identified SERPINH1 as a putative CyPA-binding protein, using liquid chromatography-electrospray mass spectrometry (LC-MS)/MS. SERPINH1 was found to be upregulated in the placentae of PE. Silencing SERPINH1 expression reversed the upregulation of ECM proteins and inhibition of the EMT process induced by the overexpression of CyPA. These findings revealed the functions of CyPA in the impaired invasiveness of trophoblasts in PE and indicated that CyPA and SERPINH1 may represent promising targets for the treatment of PE.

COL5A1 Serves as a Biomarker of Tumor Progression and Poor Prognosis and May Be a Potential Therapeutic Target in Gliomas

Glioma is the most common malignancy of the central nervous system. Although advances in surgical resection, adjuvant radiotherapy, and chemotherapy have been achieved in the last decades, the prognosis of gliomas is still dismal. COL5A1 is one of the collagen members with minor content but prominent functions. The present study examined the biological functions, prognostic value, and gene-associated tumor-infiltrating immune cells of COL5A1 through experiments and bioinformatics analysis. We found that the overexpression of COL5A1 was positively correlated with the increasing tumor malignancies and indicated poor prognosis in gliomas. Moreover, downregulation of COL5A1 could inhibit proliferation and migration of glioma cells and enhance their temozolomide sensitivities in vitro. Further bioinformatic analysis revealed that COL5A1 and its co-expressed genes participated in a number of pathways and biological processes involved in glioma progression. Finally, we evaluated the tumor-infiltrating immune cells of gliomas depending on COL5A1 and found that the percentages of the dendritic cells, which were known as the central mediator of tumor microenvironment in gliomas, were positively associated with the expression levels of COL5A1. Taken together, COL5A1 is an important biomarker and potential therapeutic target of gliomas.

DNA Methylation-based Diagnostic and Prognostic Biomarkers for Glioblastoma

Glioblastomas are the most common primary central nervous system malignancy tumor in adults. Glioblastoma patients have poor prognosis, with an average survival period of approximately 14 mo after diagnosis. To date, there are a limited number of effective treatment methods for glioblastoma, and its molecular mechanisms remain elusive. In this article, we analyzed the key biomarkers and pathways in glioblastoma patients based on gene expression and DNA methylation datasets. The 60 hypomethylated/upregulated genes and 110 hypermethylated/downregulated genes were identified in GSE50923, GSE50161, and GSE116520 microarrays. Functional enrichment analyses indicated that these methylated-differentially expressed genes were primarily involved in collagen fibril organization, chemical synaptic transmission, extracellular matrix-receptor interaction, and GABAergic synapse. The hub genes were screened from a protein–protein interaction network; in selected genes, increased NMB mRNA level was associated with favorable overall survival, while elevated CHI3L1, POSTN, S100A4, LOX, S100A11, IGFBP2, SLC12A5, VSNL1, and RGS4 mRNA levels were associated with poor overall survival in glioblastoma patients. Additionally, CHI3L1, S100A4, LOX, and S100A11 expressions were negatively correlated with their corresponding methylation status. Furthermore, the receiver-operator characteristic curve analysis indicated that CHI3L1, S100A4, LOX, and S100A11 can also serve as highly specific and sensitive diagnostic biomarkers for glioblastoma patients. Collectively, our study revealed the possible methylated-differentially expressed genes and associated pathways in glioblastoma and identified four DNA methylation-based biomarkers of glioblastoma. These results may provide insight on diagnostic and prognostic biomarkers, and therapeutic targets in glioblastoma.

Brain Tumor-Derived Extracellular Vesicles as Carriers of Disease Markers: Molecular Chaperones and MicroRNAs

Primary and metastatic brain tumors are usually serious conditions with poor prognosis, which reveal the urgent need of developing rapid diagnostic tools and efficacious treatments. To achieve these objectives, progress must be made in the understanding of brain tumor biology, for example, how they resist natural defenses and therapeutic intervention. One resistance mechanism involves extracellular vesicles that are released by tumors to meet target cells nearby or distant via circulation and reprogram them by introducing their cargo. This consists of different molecules among which are microRNAs (miRNAs) and molecular chaperones, the focus of this article. miRNAs modify target cells in the immune system to avoid antitumor reaction and chaperones are key survival molecules for the tumor cell. Extracellular vesicles cargo reflects the composition and metabolism of the original tumor cell; therefore, it is a source of markers, including the miRNAs and chaperones discussed in this article, with potential diagnostic and prognostic value. This and their relatively easy availability by minimally invasive procedures (e.g., drawing venous blood) illustrate the potential of extracellular vesicles as useful materials to manage brain tumor patients. Furthermore, understanding extracellular vesicles circulation and interaction with target cells will provide the basis for using this vesicle for delivering therapeutic compounds to selected tumor cells.

Extracellular Chaperones as Novel Biomarkers of Overall Cancer Progression and Efficacy of Anticancer Therapy

Exosomal heat shock proteins (Hsps) are involved in intercellular communication both in physiological and pathological conditions. They play a role in key processes of carcinogenesis including immune system regulation, cell differentiation, vascular homeostasis and metastasis formation. Thus, exosomal Hsps are emerging biomarkers of malignancies and possible therapeutic targets. Adolescents and young adults (AYAs) are patients aged 15–39 years. This age group, placed between pediatric and adult oncology, pose a particular challenge for cancer management. New biomarkers of cancer growth and progression as well as prognostic factors are desperately needed in AYAs. In this review, we attempted to summarize the current knowledge on the role of exosomal Hsps in selected solid tumors characteristic for the AYA population and/or associated with poor prognosis in this age group. These included malignant melanoma, brain tumors, and breast, colorectal, thyroid, hepatocellular, lung and gynecological tract carcinomas. The studies on exosomal Hsps in these tumors are limited; however; some have provided promising results. Although further research is needed, there is potential for future clinical applications of exosomal Hsps in AYA cancers, both as novel biomarkers of disease presence, progression or relapse, or as therapeutic targets or tools for drug delivery.

Evidence of stage progression in a novel, validated fluorescence-navigated and microsurgical-assisted secondary lymphedema rodent model

Secondary lymphedema (SL)is a frequent and devastating complication of modern oncological therapy and filarial infections. A lack of a reliable preclinical model to investigate the underlying mechanism of clinical stage progression has limited the development of new therapeutic strategies. Current first line treatment has shown to be merely symptomatic and relies on lifetime use of compression garments and decongestive physiotherapy. In this study, we present the development of a secondary lymphedema model in 35 rats using pre- and intraoperative fluorescence-guided mapping of the lymphatics and microsurgical induction. In contrast to the few models reported so far, we decided to avoid the use of radiation for lymphedema induction. It turned out, that the model is nearly free of complications and capable of generating a statistically significant limb volume increase by water displacement measurements, sustained for at least 48 days. A translational, accurate lymphatic dysfunction was visualized by a novel VIS-NIR X-ray ICG-Clearance-Capacity imaging technology. For the first-time SL stage progression was validated by characteristic histological alterations, such as subdermal mast cell infiltration, adipose tissue deposition, and fibrosis by increased skin collagen content. Immunofluorescence confocal microscopy analysis suggested that stage progression is related to the presence of a characteristic α SMA+/HSP-47+/vimentin+ fibroblast subpopulation phenotype. These findings demonstrate that the in-vivo model is a reliable and clinically relevant SL model for the development of further secondary lymphedema therapeutic strategies and the analysis of the veiled molecular mechanisms of lymphatic dysfunction.

Network Analyses of the Differential Expression of Heat Shock Proteins in Glioma

Heat shock protein (HSP) is a family of highly conserved protein, which exists widely in various organisms and has a variety of important physiological functions. Currently, there is no systematic analysis of HSPs in human glioma. The aim of this study was to investigate the characteristics of HSPs through constructing protein-protein interaction network (PPIN) considering the expression level of HSPs in glioma. After the identification of the differentially expressed HSPs in glioma tissues, a specific PPIN was constructed and found that there were many interactions between the differentially expressed HSPs in glioma. Subcellular localization analysis shows that HSPs and their interacting proteins distribute from the cell membrane to the nucleus in a multilayer structure. By functional enrichment analysis, gene ontology analysis, and Kyoto Encyclopedia of Genes and Genomes pathway analysis, the potential function of HSPs and two meaningful enrichment pathways was revealed. In addition, nine HSPs (DNAJA4, DNAJC6, DNAJC12, HSPA6, HSP90B1, DNAJB1, DNAJB6, DNAJC10, and SERPINH1) are prognostic markers for human brain glioma. These analyses provide a full view of HSPs about their expression, biological process, as well as clinical significance in glioma.

Xiaochaihu decorction relieves liver fibrosis caused by Schistosoma japonicum infection via the HSP47/TGF-β pathway

Background

Hepatic fibrosis caused by chronic infection with Schistosoma japonica remains a serious public health problem in the world. Symptoms include inflammation, liver granuloma and fibrosis, whilst treatment options are still limited. This study aims to investigate whether and how traditional Chinese medicine Xiaochaihu decoction (XCH) could mitigate liver fibrosis caused by S. japonicum infection.

Methods

BALB/c mice were infected with S. japonicum cercariae and treated with XCH for 16 weeks. Liver pathological changes were assessed by H&E and Masson staining. NIH3T3 and Raw264.7 cells were treated with S. japonicum egg antigens with or without XCH treatment. Quantitative real-time PCR, western blot, immunfluorescence and ELISA were performed to determine the changes of levels of fibrogenic markers.

Results

XCH protected mouse liver from injuries and fibrosis caused by S. japonicum infection and considerably reduced egg burden in a dose-dependent manner. Infection with S. japonicum caused elevation of serum ALT, AST, ALP, HA and PIIINP levels and reduction of ALB and GLOB levels, which was markedly suppressed by XCH. The upregulation of TGF-β1, Hsp47, α-SMA, Col1A1 and Col3A1 in S. japonicum-infected mouse liver was also significantly inhibited by XCH. Schistosoma japonicum egg antigens promoted the expression of Hsp47, TGF-β1, Timp-1, α-SMA, Col1A1 and Col3A1 in NIH3T3 cells, and TGF-β1, CTGF, IL-13, IL-17 and IL-6 in Raw264.7 cells, which was inhibited by XCH, LY2157299 and shRNA-Hsp47.

Conclusions

These results demonstrated that the hepatic protective effects of Xiaochaihu decoction were mediated by HSP47/TGF-β axis.

Identification of putative biomarkers for Infantile Hemangiomas and Propranolol treatment via data integration

Infantile hemangiomas (IHs) are the most common benign tumors in early childhood. They show a distinctive mechanism of tumor growth in which a rapid proliferative phase is followed by a regression phase (involution). Propranolol is an approved treatment for IHs, but its mechanism of action remains unclear. We integrated and harmonized microRNA and mRNA transcriptome data from newly generated microarray data on IHs with publicly available data on toxicological transcriptomics from propranolol exposure, and with microRNA data from IHs and propranolol exposure. We identified subsets of putative biomarkers for proliferation and involution as well as a small set of putative biomarkers for propranolol's mechanism of action for IHs, namely EPAS1, LASP1, SLC25A23, MYO1B, and ALDH1A1. Based on our integrative data approach and confirmatory experiments, we concluded that hypoxia in IHs is regulated by EPAS1 (HIF-2α) instead of HIF-1α, and also that propranolol-induced apoptosis in endothelial cells may occur via mitochondrial stress.

Self-Renewal Signalling Pathway Inhibitors: Perspectives on Therapeutic Approaches for Cancer Stem Cells

The poor survival and prognosis of individuals with cancer are often attributed to tumour relapse and metastasis, which may be due to the presence of cancer stem cells (CSCs). CSCs have the characteristics of self-renewal, differentiation potential, high carcinogenicity, and drug resistance. In addition, CSCs exhibit many characteristics similar to those of embryonic or tissue stem cells while displaying persistent abnormal activation of self-renewal pathways associated with development and tissue homeostasis, including the Wnt, Notch, Hedgehog (Hh), TGF-β, JAK/STAT3, and NF-κB pathways. Therefore, we can eliminate CSCs by targeting these self-renewal pathways to constrain stem cell replication, survival and differentiation. At the same time, we cannot neglect the ping-pong effect of the tumour microenvironment, which releases cytokines and promotes self-renewal pathways in CSCs. Recently, meaningful progress has been made in the study of inhibitors of self-renewal pathways in tumours. This review primarily summarizes several representative and novel agents targeting these self-renewal signalling pathways and the tumour microenvironment and that represent a promising strategy for treating refractory and recurrent cancer.

Heat Shock Proteins in Glioblastoma Biology: Where Do We Stand?

Heat shock proteins (HSPs) are evolutionary conserved proteins that work as molecular chaperones and perform broad and crucial roles in proteostasis, an important process to preserve the integrity of proteins in different cell types, in health and disease. Their function in cancer is an important aspect to be considered for a better understanding of disease development and progression. Glioblastoma (GBM) is the most frequent and lethal brain cancer, with no effective therapies. In recent years, HSPs have been considered as possible targets for GBM therapy due their importance in different mechanisms that govern GBM malignance. In this review, we address current evidence on the role of several HSPs in the biology of GBMs, and how these molecules have been considered in different treatments in the context of this disease, including their activities in glioblastoma stem-like cells (GSCs), a small subpopulation able to drive GBM growth. Additionally, we highlight recent works that approach other classes of chaperones, such as histone and mitochondrial chaperones, as important molecules for GBM aggressiveness. Herein, we provide new insights into how HSPs and their partners play pivotal roles in GBM biology and may open new therapeutic avenues for GBM based on proteostasis machinery.

Heat shock protein 47 (HSP47) binds to discoidin domain-containing receptor 2 (DDR2) and regulates its protein stability

Cell-collagen interactions are crucial for cell migration and invasion during cancer development and progression. Heat shock protein 47 (HSP47) is an endoplasmic reticulum-resident molecular chaperone that facilitates collagen maturation and deposition. It has been previously shown that HSP47 expression in cancer cells is crucial for cancer invasiveness. However, exogenous collagen cannot rescue cell invasion in HSP47-silenced cancer cells, suggesting that other HSP47 targets contribute to cancer cell invasion. Here, we show that HSP47 expression is required for the stability and cell-surface expression of discoidin domain-containing receptor 2 (DDR2) in breast cancer tissues. HSP47 silencing reduced DDR2 protein stability, accompanied by suppressed cell migration and invasion. Co-immunoprecipitation results revealed that HSP47 binds to the DDR2 ectodomain. Using a photoconvertible technique and total internal reflection fluorescence microscopy, we further demonstrate that HSP47 expression significantly sustains the membrane localization of the DDR2 protein. These results suggest that binding of HSP47 to DDR2 increases DDR2 stability and regulates its membrane dynamics and thereby enhances cancer cell migration and invasion. Given that DDR2 has a crucial role in the epithelial-to-mesenchymal transition and cancer progression, targeting the HSP47-DDR2 interaction might be a potential strategy for inhibiting DDR2-dependent cancer progression.

Molecular chaperones in the brain endothelial barrier: neurotoxicity or neuroprotection?

Brain microvascular endothelial cells (BMECs) interact with astrocytes and pericytes to form the blood-brain barrier (BBB). Their compromised function alters the BBB integrity, which is associated with early events in the pathogenesis of cancer, neurodegenerative diseases, and epilepsy. Interestingly, these conditions also induce the expression of heat shock proteins (HSPs). Here we review the contribution of major HSP families to BMEC and BBB function. Although investigators mainly report protective effects of HSPs in brain, contrasted results were obtained in BMEC, which depend both on the HSP and on its location, intra- or extracellular. The therapeutic potential of HSPs must be scrupulously analyzed before targeting them in patients to reduce the progression of brain lesions and improve neurologic outcomes in the long term.-Thuringer, D., Garrido, C. Molecular chaperones in the brain endothelial barrier: neurotoxicity or neuroprotection?

miR-455-3p Alleviates Hepatic Stellate Cell Activation and Liver Fibrosis by Suppressing HSF1 Expression

Liver fibrosis is a common pathological process of end-stage liver diseases. However, the role of microRNA (miRNA) in liver fibrosis is poorly understood. The activated hepatic stellate cells (HSCs) are the major source of fibrogenic cells and play a central role in liver fibrosis. In this study, we investigated the differential expression of miRNAs in resting and transforming growth factor β1 (TGF-β1) activated HSCs by microarray analysis and found that miR-455-3p was significantly downregulated during HSCs activation. In addition, the reduction of miR-455-3p was correlated with liver fibrosis in mice with carbon tetrachloride (CCl₄), bile duct ligation (BDL), and high-fat diet (HFD)-induced liver fibrosis. Our functional analyses demonstrated that miR-455-3p inhibited expression of profibrotic markers and cell proliferation in HSCs in vitro. Moreover, miR-455-3p regulated heat shock factor 1 (HSF1) expression by binding to the 3′ UTR of its mRNA directly. Overexpression of HSF1 facilitated HSCs activation and proliferation by promoting heat shock protein 47 (Hsp47) expression, leading to activation of the TGF-β/Smad4 signaling pathway. To explore the clinical potential of miR-455-3p, we injected ago-miR-455-3p into mice with CCl₄-, BDL-, and HFD-induced hepatic fibrosis in vivo. The overexpression of miR-455-3p suppressed HSF1 expression and reduced fibrosis marker expression, which resulted in alleviated liver fibrosis in mice. In conclusion, our present study suggests that miR-455-3p inhibits the activation of HSCs through targeting HSF1 involved in the Hsp47/TGF-β/Smad4 signaling pathway. Therefore, miR-455-3p might be a promising therapeutic target for liver fibrosis.

Current Challenges and Opportunities in Treating Glioblastoma

Glioblastoma multiforme (GBM), the most common and aggressive primary brain tumor, has a high mortality rate despite extensive efforts to develop new treatments. GBM exhibits both intra- and intertumor heterogeneity, lending to resistance and eventual tumor recurrence. Large-scale genomic and proteomic analysis of GBM tumors has uncovered potential drug targets. Effective and “druggable” targets must be validated to embark on a robust medicinal chemistry campaign culminating in the discovery of clinical candidates. Here, we review recent developments in GBM drug discovery and delivery. To identify GBM drug targets, we performed extensive bioinformatics analysis using data from The Cancer Genome Atlas project. We discovered 20 genes, BOC, CLEC4GP1, ELOVL6, EREG, ESR2, FDCSP, FURIN, FUT8-AS1, GZMB, IRX3, LITAF, NDEL1, NKX3-1, PODNL1, PTPRN, QSOX1, SEMA4F, TH, VEGFC, and C20orf166AS1 that are overexpressed in a subpopulation of GBM patients and correlate with poor survival outcomes. Importantly, nine of these genes exhibit higher expression in GBM versus low-grade glioma and may be involved in disease progression. In this review, we discuss these proteins in the context of GBM disease progression. We also conducted computational multi-parameter optimization to assess the blood-brain barrier (BBB) permeability of small molecules in clinical trials for GBM treatment. Drug delivery in the context of GBM is particularly challenging because the BBB hinders small molecule transport. Therefore, we discuss novel drug delivery methods, including nanoparticles and prodrugs. Given the aggressive nature of GBM and the complexity of targeting the central nervous system, effective treatment options are a major unmet medical need. Identification and validation of biomarkers and drug targets associated with GBM disease progression present an exciting opportunity to improve treatment of this devastating disease.

Development of a Gill Assay Library for Ecological Proteomics of Threespine Sticklebacks (Gasterosteus aculeatus)

A data-independent acquisition (DIA) assay library for quantitative analyses of proteome dynamics has been developed for gills of threespine sticklebacks (Gasterosteus aculeatus). A raw spectral library was generated by data-dependent acquisition (DDA) and annotation of tryptic peptides to MSMS spectra and protein database identifiers. The assay library was constructed from the raw spectral library by removal of low-quality, ambiguous, and low-signal peptides. Only unique proteins represented by at least two peptides are included in the assay library, which consists of 1506 proteins, 5074 peptides, 5104 precursors, and 25,322 transitions. This assay library was used with DIA data to identify biochemical differences in gill proteomes of four populations representing different eco- and morpho-types of threespine sticklebacks. The assay library revealed unique and reproducible proteome signatures. Warm-adapted, low-plated, brackish-water fish from Laguna de la Bocana del Rosario (Mexico) show elevated HSP47, extracellular matrix, and innate immunity proteins whereas several immunoglobulins, interferon-induced proteins, ubiquitins, proteolytic enzymes, and nucleic acid remodeling proteins are reduced. Fully-plated, brackish-water fish from Westchester Lagoon (Alaska) display elevated ion regulation, GTPase signaling, and contractile cytoskeleton proteins, altered abundances of many ribosomal, calcium signaling and immunity proteins, and depleted transcriptional regulators and metabolic enzymes. Low-plated freshwater fish from Lake Solano (California) have elevated inflammasomes and proteolytic proteins whereas several iron containing and ion regulatory proteins are reduced. Gills of fully-plated, marine fish from Bodega Harbor (California) have elevated oxidative metabolism enzymes and reduced transglutaminase 2, collagens, and clathrin heavy chains. These distinct proteome signatures represent targets for testing ecological and evolutionary influences on molecular mechanisms of gill function in threespine sticklebacks. Furthermore, the gill assay library represents a model for other tissues and paves the way for accurate and reproducible network analyses of environmental context-dependent proteome dynamics in complex organisms.

The comparison genomics analysis with glioblastoma multiforme (GBM) cells under 3D and 2D cell culture conditions

GBM, the most common and aggressive malignant primary brain tumors which needs new research approach to reveal the underline molecular mechanism of tumor progression. The 3D in vitro tumor model can be a simple and effective way to study tumor characteristics with ability to replicate of the tumor milieu. In the current study, we adopted the DNA microarray to analyze the gene expression of GBM tumor cells cultured under 2D cell culture flasks and 3D PLA porous scaffolds for 4,7 and 14 days. For 14 day old cultures, 8117 and 3060 genes expression were upregulated and downregulated respectively. Further KEGG pathway analysis revealed, the upregulated genes were mainly enriched/involved in PPAR and PI3K-Akt signaling pathways whereas the downregulated genes were mainly contributed in metabolism, ECM related and TGF-beta pathways. Thus, our approach of establishing 3D in vitro tumor model provides realistic results and proves itself a powerful tool for understanding the inner nature of GBM and can be considered as potential platform for drug screening.

The heat shock protein 47 as a potential biomarker and a therapeutic agent in cancer research

Heat shock protein 47 (HSP47) is an important chaperone required for the correct folding and secretion of collagen. Several studies revealed that HSP47 has a role in numerous steps of collagen synthesis, preventing procollagen aggregation and inducing hydroxylation of proline and lysine residues. HSP47 is encoded by the SERPINH1 gene, which is located on chromosome 11q13.5, one of the most frequently amplified regions in human cancer. The altered expression levels of HSP47 have been correlated with several types of cancer, such as cervical, breast, pancreatic and gastric cancers. Studies have shown that HSP47 promotes tumor angiogenesis, growth, migration and metastatic capacity. In this review, we highlight the fundamental aspects of the interaction between HSP47 and collagen and the recent discoveries of the role of this chaperone in different types of malignant neoplasias. We also discuss recent treatments using HSP47 as a therapeutic target, and present evidences that HSP47 is an essential protein for cancer biology and a potential molecular target for chemotherapy.

Tumor-associated macrophage-derived cytokines enhance cancer stem-like characteristics through epithelial-mesenchymal transition

Cancer stem cells are a small population of cells with the potential for self-renewal and multi-directional differentiation and are an important source of cancer initiation, treatment resistance, and recurrence. Epithelial-mesenchymal transition (EMT) is a process in which epithelial cells lose their epithelial phenotype and convert to mesenchymal cells. Recent studies have shown that cancer cells undergoing EMT can become stem-like cells. Many kinds of tumors are associated with chronic inflammation, which plays a role in tumor progression. Among the various immune cells mediating chronic inflammation, macrophages account for ~30%-50% of the tumor mass. Macrophages are highly infiltrative in the tumor microenvironment and secrete a series of inflammatory factors and cytokines, such as transforming growth factor (TGF)-β, IL-6, IL-10, and tumor necrosis factor (TNF)-α, which promote EMT and enhance the stemness of cancer cells. This review summarizes and discusses recent research findings on some specific mechanisms of tumor-associated macrophage-derived cytokines in EMT and cancer stemness transition, which are emerging targets of cancer treatment.

Biomimetic models to examine microenvironmental regulation of glioblastoma stem cells

Glioblastoma multiforme (GBM), a malignant brain tumor, is the deadliest form of human cancer with low survival rates because of its highly invasive nature. In recent years, there has been a growing appreciation for the role that glioblastoma stem cells (GSCs) play during tumorigenesis and tumor recurrence of GBM. GSCs are a specialized subset of GBM cells with stem cell-like features that contribute to tumor initiation and therapeutic resistance. Thus, to enhance therapeutic efficiency and improve survival, targeting GSCs and their microenvironmental niche appears to be a promising approach. To develop this approach, understanding GSC-microenvironment interactions is crucial. This review discusses various biomimetic model systems to understand the impact of biophysical, biochemical, and cellular microenvironmental cues on GSC behaviors. These models include two-dimensional or matrix-free environment models, engineered biomaterial-based three-dimensional models, co-culture models, and mouse and rat in vivo models. These systems have been used to study the effects of biophysical factors, modulation of signaling pathways, extracellular matrix components, and culture conditions on the GSC phenotype. The advantages and disadvantages of these model systems and their impact in the field of GSC research are discussed.

Deciphering molecular mechanisms of arginine deiminase-based therapy - Comparative response analysis in paired human primary and recurrent glioblastomas

Arginine auxotrophy constitutes the Achilles' heel for several tumors, among them glioblastoma multiforme (GBM). Hence, arginine-depleting enzymes such as arginine deiminase (ADI) from Streptococcus pyogenes are promising for treatment of primary and maybe even refractory GBM. Based on our previous study in which ADI-susceptibility was shown on a panel of patient-derived GBM cell lines, we here aimed at deciphering underlying molecular mechanisms of ADI-mediated growth inhibition. We found that ADI (35 mU/mL) initially induces a cellular stress-response that is characterized by upregulation of genes primarily belonging to the heat-shock protein family. In addition to autophagocytosis, we show for the first time that senescence constitutes another cellular response mechanism upon ADI-treatment and that this bacterial enzyme is able to act as radiosensitizer (¼ cases). Long-term treatment schedules revealed no resistance development, with treated cells showing morphological signs of cell stress. Next, several combination strategies were employed to optimize ADI-based treatment. Simultaneous and sequential S. pyogenes ADI-based combinations included substances acting at different molecular pathways (curcumin, resveratrol, quinacrine, and sorafenib, 2 × 72 h treatment). Adding drugs to GBM cell lines (n = 4, including a matched pair of primary and recurrent GBM in one case) accelerated and potentiated ADI-mediated cytotoxicity. Autophagy was identified as the main cause of tumor growth inhibition. Of note, residual cells again showed classical signs of senescence in most combinations. Our results suggest an alternative treatment regimen for this fatal cancer type which circumvents many of the traditional barriers. Using the metabolic defect in GBM thus warrants further (pre-) clinical evaluation.