Silk-Based 3D Porous Scaffolds for Tissue Engineering.

Silk fibroin, extracted from the silk of the Bombyx mori silkworm, stands out as a biomaterial due to its nontoxic nature, excellent biocompatibility, and adjustable biodegradability. Porous scaffolds, a type of biomaterial, are crucial for creating an optimal microenvironment that supports cell adhesion and proliferation, thereby playing an essential role in tissue remodeling and repair. Therefore, this review focuses on 3D porous silk fibroin-based scaffolds, first summarizing their preparation methods and then detailing their regenerative effects on bone, cartilage, tendon, vascular, neural, skin, hepatic, and tracheal epithelial tissue engineering in recent years.

Comprehensive understanding of glioblastoma molecular phenotypes: classification, characteristics, and transition.

Among central nervous system-associated malignancies, glioblastoma (GBM) is the most common and has the highest mortality rate. The high heterogeneity of GBM cell types and the complex tumor microenvironment frequently lead to tumor recurrence and sudden relapse in patients treated with temozolomide. In precision medicine, research on GBM treatment is increasingly focusing on molecular subtyping to precisely characterize the cellular and molecular heterogeneity, as well as the refractory nature of GBM toward therapy. Deep understanding of the different molecular expression patterns of GBM subtypes is critical. Researchers have recently proposed tetra fractional or tripartite methods for detecting GBM molecular subtypes. The various molecular subtypes of GBM show significant differences in gene expression patterns and biological behaviors. These subtypes also exhibit high plasticity in their regulatory pathways, oncogene expression, tumor microenvironment alterations, and differential responses to standard therapy. Herein, we summarize the current molecular typing scheme of GBM and the major molecular/genetic characteristics of each subtype. Furthermore, we review the mesenchymal transition mechanisms of GBM under various regulators.

Deep-targeted gene sequencing reveals ARID1A mutation as an important driver of glioblastoma.

AIMS: To investigate the key factors influencing glioma progression and the emergence of treatment resistance by examining the intrinsic connection between mutations in DNA damage and repair-related genes and the development of chemoresistance in gliomas. METHODS: We conducted a comprehensive analysis of deep-targeted gene sequencing data from 228 glioma samples. This involved identifying differentially mutated genes across various glioma grades, assessing their functions, and employing I-TASSER for homology modeling. We elucidated the functional changes induced by high-frequency site mutations in these genes and investigated their impact on glioma progression. RESULTS: The analysis of sequencing mutation results of deep targeted genes in integration revealed that ARID1A gene mutation occurs frequently in glioblastoma and alteration of ARID1A could affect the tolerance of glioma cells to temozolomide treatment. The deletion of proline at position 16 in the ARID1A protein affected the stability of binding of the SWI/SNF core subunit BRG1, which in turn affected the stability of the SWI/SNF complex and led to altered histone modifications in the CDKN1A promoter region, thereby affecting the biological activity of glioma cells, as inferred from modeling and protein interaction analysis. CONCLUSION: The ARID1A gene is a critical predictive biomarker for glioma. Mutations at the ARID1A locus alter the stability of the SWI/SNF complex, leading to changes in transcriptional regulation in glioma cells. This contributes to an increased malignant phenotype of GBM and plays a pivotal role in mediating chemoresistance.

EPIC-1042 as a potent PTRF/Cavin1-caveolin-1 interaction inhibitor to induce PARP1 autophagic degradation and suppress temozolomide efflux for glioblastoma.

BACKGROUND: Temozolomide (TMZ) treatment efficacy in glioblastoma is determined by various mechanisms such as TMZ efflux, autophagy, base excision repair (BER) pathway, and the level of O6-methylguanine-DNA methyltransferase (MGMT). Here, we reported a novel small-molecular inhibitor (SMI) EPIC-1042 (C20H28N6) with the potential to decrease TMZ efflux and promote PARP1 degradation via autolysosomes in the early stage. METHODS: EPIC-1042 was obtained from receptor-based virtual screening. Co-immunoprecipitation and pull-down assays were applied to verify the blocking effect of EPIC-1042. Western blotting, co-immunoprecipitation, and immunofluorescence were used to elucidate the underlying mechanisms of EPIC-1042. In vivo experiments were performed to verify the efficacy of EPIC-1042 in sensitizing glioblastoma cells to TMZ. RESULTS: EPIC-1042 physically interrupted the interaction of PTRF/Cavin1 and caveolin-1, leading to reduced secretion of small extracellular vesicles (sEVs) to decrease TMZ efflux. It also induced PARP1 autophagic degradation via increased p62 expression that more p62 bound to PARP1 and specially promoted PARP1 translocation into autolysosomes for degradation in the early stage. Moreover, EPIC-1042 inhibited autophagy flux at last. The application of EPIC-1042 enhanced TMZ efficacy in glioblastoma in vivo. CONCLUSION: EPIC-1042 reinforced the effect of TMZ by preventing TMZ efflux, inducing PARP1 degradation via autolysosomes to perturb the BER pathway and recruitment of MGMT, and inhibiting autophagy flux in the later stage. Therefore, this study provided a novel therapeutic strategy using the combination of TMZ with EPIC-1042 for glioblastoma treatment.

Blockage of EGFR/AKT and mevalonate pathways synergize the antitumor effect of temozolomide by reprogramming energy metabolism in glioblastoma.

BACKGROUND: Metabolism reprogramming plays a vital role in glioblastoma (GBM) progression and recurrence by producing enough energy for highly proliferating tumor cells. In addition, metabolic reprogramming is crucial for tumor growth and immune-escape mechanisms. Epidermal growth factor receptor (EGFR) amplification and EGFR-vIII mutation are often detected in GBM cells, contributing to the malignant behavior. This study aimed to investigate the functional role of the EGFR pathway on fatty acid metabolism remodeling and energy generation. METHODS: Clinical GBM specimens were selected for single-cell RNA sequencing and untargeted metabolomics analysis. A metabolism-associated RTK-fatty acid-gene signature was constructed and verified. MK-2206 and MK-803 were utilized to block the RTK pathway and mevalonate pathway induced abnormal metabolism. Energy metabolism in GBM with activated EGFR pathway was monitored. The antitumor effect of Osimertinib and Atorvastatin assisted by temozolomide (TMZ) was analyzed by an intracranial tumor model in vivo. RESULTS: GBM with high EGFR expression had characteristics of lipid remodeling and maintaining high cholesterol levels, supported by the single-cell RNA sequencing and metabolomics of clinical GBM samples. Inhibition of the EGFR/AKT and mevalonate pathways could remodel energy metabolism by repressing the tricarboxylic acid cycle and modulating ATP production. Mechanistically, the EGFR/AKT pathway upregulated the expressions of acyl-CoA synthetase short-chain family member 3 (ACSS3), acyl-CoA synthetase long-chain family member 3 (ACSL3), and long-chain fatty acid elongation-related gene ELOVL fatty acid elongase 2 (ELOVL2) in an NF-κB-dependent manner. Moreover, inhibition of the mevalonate pathway reduced the EGFR level on the cell membranes, thereby affecting the signal transduction of the EGFR/AKT pathway. Therefore, targeting the EGFR/AKT and mevalonate pathways enhanced the antitumor effect of TMZ in GBM cells and animal models. CONCLUSIONS: Our findings not only uncovered the mechanism of metabolic reprogramming in EGFR-activated GBM but also provided a combinatorial therapeutic strategy for clinical GBM management.

Effects of organic mulching on moisture and temperature of soil in greenhouse production of tomato under unheated greenhouse cultivation in the cold zone of China.

In the cold zone of China, winter is cold and long and has a short duration of sunshine. Unheated earthen-wall solar greenhouses are used for tomato production in winter in this region. This was an experimental investigation of different organic mulching materials (newspaper, bran, and grass) on the soil temperature, soil moisture, tomato yield, fruit quality, and water use efficiency. Organic mulching variously improved soil temperature, soil moisture, water use efficiency, and tomato yield, which is very important for greenhouse winter cultivation in this cold zone. Organic mulching regulated the soil temperature, with daily soil temperature ranges of bran, newspaper, and grass treatments being 1.6, 1.9, and 2.1°C lower than for bare land, respectively. Compared to bare land, newspaper mulching had little effect on soil temperature and fruit quality, but increased soil moisture (14.1%) and water use efficiency (WUE: WUEb, 31.3%; WUEy, 30.6%), and greatly increased yield (81.8%) and biomass (82.7%); bran mulching greatly increased soil temperature, moisture (16%), and WUE (WUEb, 60.1%; WUEy, 44.3%) and increased biomass (30.2%) and yield (17.3%); grass mulching greatly increased soil temperature and moisture (20.9%) and increased biomass (17.9%), yield (11.2%), and WUE (WUEb, 20.5%; WUEy, 13.6%). In addition, organic mulching had a good water retention effect on soil layer above 30 cm. The total soil water consumption during tomato growth was in the following order: newspaper (103 mm) > bare (74 mm) > grass (73 mm) > bran (60 mm). Soil water consumption mainly occurred in the 0- to 10-cm soil layers.

EPIC-0307-mediated selective disruption of PRADX-EZH2 interaction and enhancement of temozolomide sensitivity to glioblastoma via inhibiting DNA repair and MGMT.

BACKGROUND: Temozolomide (TMZ) treatment efficacy in glioblastoma (GBM) has been limited by resistance. The level of O-6-methylguanine-DNA methyltransferase (MGMT) and intrinsic DNA damage repair factors are important for the TMZ response in patients. Here, we reported a novel compound, called EPIC-0307, that increased TMZ sensitivity by inhibiting specific DNA damage repair proteins and MGMT expression. METHODS: EPIC-0307 was derived by molecular docking screening. RNA immunoprecipitation (RIP), and chromatin immunoprecipitation by RNA (ChIRP) assays were used to verify the blocking effect. Chromatin immunoprecipitation (ChIP) and co-immunoprecipitation (Co-IP) assays were performed to explore the mechanism of EPIC-0307. A series of in vivo and in vitro experiments were designed to evaluate the efficacy of EPIC-0307 in sensitizing GBM cells to TMZ. RESULTS: EPIC-0307 selectively disrupted the binding of PRADX to EZH2 and upregulated the expression of P21 and PUMA, leading to cell cycle arrest and apoptosis in GBM cells. EPIC-0307 exhibited a synergistic inhibitory effect on GBM when combined with TMZ by downregulating TMZ-induced DNA damage repair responses and epigenetically silencing MGMT expression through modulating the recruitment of ATF3-pSTAT3-HDAC1 regulatory complex to the MGMT promoter. EPIC-0307 demonstrated significant efficacy in suppressing the tumorigenesis of GBM cells, restoring TMZ sensitivity. CONCLUSION: This study identified a potential small-molecule inhibitor (SMI) EPIC-0307 that selectively disrupted the PRADX-EZH2 interaction to upregulate expressions of tumor suppressor genes, thereby exerting its antitumor effects on GBM cells. EPIC-0307 treatment also increased the chemotherapeutic efficacy of TMZ by epigenetically downregulating DNA repair-associate genes and MGMT expression in GBM cells.

Regenerated silk fibroin based on small aperture scaffolds and marginal sealing hydrogel for osteochondral defect repair.

BACKGROUND: Osteochondral defects pose an enormous challenge without satisfactory repair strategy to date. In particular, the lateral integration of neo-cartilage into the surrounding native cartilage is a difficult and inadequately addressed problem determining tissue repair's success. METHODS: Regenerated silk fibroin (RSF) based on small aperture scaffolds was prepared with n-butanol innovatively. Then, the rabbit knee chondrocytes and bone mesenchymal stem cells (BMSCs) were cultured on RSF scaffolds, and after induction of chondrogenic differentiation, cell-scaffold complexes strengthened by a 14 wt% RSF solution were prepared for in vivo experiments. RESULTS: A porous scaffold and an RSF sealant exhibiting biocompatibility and excellent adhesive properties are developed and confirmed to promote chondrocyte migration and differentiation. Thus, osteochondral repair and superior horizontal integration are achieved in vivo with this composite. CONCLUSIONS: Overall, the new approach of marginal sealing around the RSF scaffolds exhibits preeminent repair results, confirming the ability of this novel graft to facilitate simultaneous regeneration of cartilage-subchondral bone.

Proteomic approach-based comparison of metabolic pathways and functional activities of whey proteins derived from Guishan and Saanen goat milk.

Guishan goats, a unique goat breed in Yunnan Province, have a long history and representation, but their whey protein and function remain unclear. In this study, we carried out a quantitative analysis of the Guishan and Saanen goat whey proteome using a label-free proteomic approach. A total of 500 proteins were quantified from the 2 kinds of goat whey proteins, including 463 common proteins, 37 uniquely expressed whey proteins (UEWP), and 12 differentially expressed whey proteins (DEWP). Bioinformatics analysis indicated that UEWP and DEWP were mainly involved in cellular and immune system processes, membrane, and binding. In addition, UEWP and DEWP in Guishan goats participated primarily in metabolism and immune-related pathways, whereas Saanen goat whey proteins were associated mostly with environmental information processing-related pathways. Guishan goat whey promoted the growth of RAW264.7 macrophages more than Saanen goat whey, and significantly reduced the production of nitric oxide in lipopolysaccharide-stimulated RAW264.7 cells. This study provides a reference for further understanding these 2 goat whey proteins and finding functional active substances from them.

Hydrological characteristics of different organic materials mulches.

The study aims to find the properties of three organic mulch varieties and their effects on soil moisture and crop growth. Three organic mulches: newspaper, grass, and bran were selected as the research objects, and were analyzed through double-ring infiltration and water loss tests so that water permeability and water-holding capacity of the three mulching materials could be figured out. The results showed the descending order of the three mulching treatments and non-treatment by the infiltration rate of the soil: newspaper > bare ground > grass > bran. In terms of the water-holding capacity, the three organic mulches can be ranked from high to low as newspaper, grass, and bran; by the cumulative water loss as newspaper, grass, and bran; and by water-retention capacity as bran, grass, and newspaper, respectively. By conducting regression analysis, it is found that the water-holding capacity of the mulches is related to water immersion time and the amount of water absorbed and that there is a significant logarithmic relationship between the amount of water loss and water losing time. The fitting results of the three mulches are good. Besides, a power-function relationship exists between water absorption rate and immersion time, and between water loss rate and water loss time. The water infiltration of the soil under the newspaper mulching treatment is the best, as the newspaper can help to improve soil moisture and weaken surface runoff under flood irrigation and heavy rain. Bran possesses the strongest capacity for water retention, which is beneficial to soil moisture retention in areas where sprinkler irrigation, drip irrigation, and light to moderate rain prevail. The research results can provide a basis for improving the moisture-utilization efficiency in farmlands by using organic mulches.

A novel compound EPIC-0412 reverses temozolomide resistance via inhibiting DNA repair/MGMT in glioblastoma.

BACKGROUND: Temozolomide (TMZ) resistance has become an important obstacle affecting its therapeutic benefits. O6-methylguanine DNA methyltransferase (MGMT) is primarily responsible for the TMZ resistance in Glioblastoma multiforme (GBM) patients. In addition, active DNA damage repair pathways can also lead to TMZ resistance. Here, we reported a novel small-molecule inhibitor EPIC-0412 that improved the therapeutic efficacy of TMZ by inhibiting the DNA damage repair pathway and MGMT in GBM via epigenetic pathways. METHODS: The small-molecule compound EPIC-0412 was obtained through high-throughput screening. RNA immunoprecipitation (RIP), chromatin isolation by RNA purification (ChIRP), and chromatin immunoprecipitation (ChIP) assays were used to verify the effect of EPIC-0412. Co-immunoprecipitation (Co-IP) was used to elucidate the interactions of transcription factors at the MGMT promoter region. Animal experiments using a mouse model were performed to verify the efficacy of EPIC-0412 in sensitizing GBM cells to TMZ. RESULTS: EPIC-0412 physically interrupts the binding of HOTAIR and EZH2, leading to the upregulation of CDKN1A and BBC3, causing cell cycle arrest and apoptosis in GBM cells. EPIC-0412 inhibits DNA damage response in GBM cells through the p21-E2F1 DNA damage repair axis. EPIC-0412 epigenetically silences MGMT through its interaction with the ATF3-p-p65-HADC1 axis at the MGMT promoter region. The application of EPIC-0412 restored the TMZ sensitivity in GBM in vivo experiments. CONCLUSION: This study discovered a small-molecule inhibitor EPIC-0412, which enhanced the chemotherapeutic effect of TMZ by acting on the p21-E2F1 DNA damage repair axis and ATF3-p-p65-MGMT axis, providing evidence for combining epigenetic drugs to increase the sensitization toward TMZ in GBM patients.

Origin, activation, and targeted therapy of glioma-associated macrophages.

The glioma tumor microenvironment plays a crucial role in the development, occurrence, and treatment of gliomas. Glioma-associated macrophages (GAMs) are the most widely infiltrated immune cells in the tumor microenvironment (TME) and one of the major cell populations that exert immune functions. GAMs typically originate from two cell types-brain-resident microglia (BRM) and bone marrow-derived monocytes (BMDM), depending on a variety of cytokines for recruitment and activation. GAMs mainly contain two functionally and morphologically distinct activation types- classically activated M1 macrophages (antitumor/immunostimulatory) and alternatively activated M2 macrophages (protumor/immunosuppressive). GAMs have been shown to affect multiple biological functions of gliomas, including promoting tumor growth and invasion, angiogenesis, energy metabolism, and treatment resistance. Both M1 and M2 macrophages are highly plastic and can polarize or interconvert under various malignant conditions. As the relationship between GAMs and gliomas has become more apparent, GAMs have long been one of the promising targets for glioma therapy, and many studies have demonstrated the therapeutic potential of this target. Here, we review the origin and activation of GAMs in gliomas, how they regulate tumor development and response to therapies, and current glioma therapeutic strategies targeting GAMs.

TCA-phospholipid-glycolysis targeted triple therapy effectively suppresses ATP production and tumor growth in glioblastoma.

Rationale: Glioblastoma (GBM) displays a complex metabolic reprogramming in cancer cells. Adenosine triphosphate (ATP) is one of the central mediators of cell metabolism and signaling. GBM cells generate ATP by glycolysis and the tricarboxylic acid (TCA) cycle associated with oxidative phosphorylation (OXPHOS) through the breaking-down of pyruvate or fatty acids to meet the growing energy demand of cancer cells. Therefore, it's urgent to develop novel treatments targeting energy metabolism to hinder tumor cell proliferation in GBM. Methods: Non-targeted metabolomic profiling analysis was utilized to evaluate cell metabolic reprogramming using a small molecule inhibitor (SMI) EPIC-0412 treatment. Cellular oxygen consumption rate (OCR) and the total proton efflux rate (PER), as well as ATP concentration, were tracked to study metabolic responses to specifically targeted inhibitors, including EPIC-0412, arachidonyl trifluoromethyl ketone (AACOCF3), and 2 deoxy-D-glucose (2-DG). Cancer cell proliferation was assessed by CCK-8 measurements and colony formation assay. Additionally, flow cytometry, immunoblotting (IB), and immunofluorescence (IF) analyses were performed with GBM cells to understand their tumorigenic properties under treatments. Finally, the anticancer effects of this combination therapy were evaluated in the GBM mouse model by convection-enhanced delivery (CED). Results: We found that SMI EPIC-0412 could effectively perturb the TCA cycle, which participated in the combination therapy of cytosolic phospholipase A2 (cPLA2)-inhibitor AACOCF3, and hexokinase II (HK2)-inhibitor 2-DG to disrupt the GBM energy metabolism for targeted metabolic treatments. ATP production was significantly declined in glioma cells when treated with monotherapy (EPIC-0412 or AACOCF3), dual therapy (EPIC-0412 + AACOCF3), or triple therapy (EPIC-0412 + AACOCF3 +2-DG) regimen. Our experiments revealed that these therapies hindered glioma cell proliferation and growth, leading to the reduction in ATP production and G0/G1 cell cycle arrest. We demonstrated that the combination therapy effectively extended the survival of cerebral tumor-bearing mice. Conclusion: Our findings indicate that the TCA-phospholipid-glycolysis metabolism axis can be blocked by specific inhibitors that significantly disrupt the tumor energy metabolism and suppress tumor proliferation in vitro and in vivo, suggesting that targeting ATP synthesis inhibition in cancer cells might be an attractive therapeutic avenue in GBM management.

PTRF/Cavin-1 enhances chemo-resistance and promotes temozolomide efflux through extracellular vesicles in glioblastoma.

Background: The concentration and duration of intracellular drugs have always been the key factors for determining the efficacy of the treatment. Efflux of chemotherapeutic drugs or anticancer agents is a major reason for multidrug resistance generation in cancer cells. The high expression of polymerase I and transcript release factor (PTRF) is correlated with a worse prognosis in glioma patients. However, the importance of PTRF on temozolomide (TMZ) resistance in glioblastoma (GBM) is poorly understood. Methods: TCGA data analysis, CGGA data analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), clone formation, cell counting kit-8 (cck-8), western blot (WB), immunofluorescence (IF), immunohistochemistry (IHC) and flow cytometry assays were performed to investigate the underlying mechanism and effect of PTRF on TMZ-resistance in a variety of GBM cell lines and GBM patient-derived xenograft (PDX) models. Clone formation, WB, IF, IHC and flow cytometry assays were performed to examine the efficacy of sequential therapy of TMZ followed by CQ in GBM cells and PDX models. Results: The prognosis of GBM patients treated with TMZ was negatively correlated with PTRF expression. Our results reveal that PTRF knockdown significantly decrease proliferation and increase apoptosis in GBM after TMZ treatment. Moreover, PTRF contribute to TMZ-resistance by increasing TMZ efflux through extracellular vesicles (EVs). Furthermore, our results demonstrate that sequential therapy of TMZ followed by CQ significantly promotes the TMZ efficacy against GBM by increasing intracellular TMZ concentration ([TMZ]i). Conclusion: This study highlights that PTRF can act as an independent biomarker to predict the prognosis of GBM patients after TMZ treatment and describes a new mechanism contributing to TMZ-resistance. In addition, this study may provide a novel idea for GBM therapy.

lncRNA PRADX is a Mesenchymal Glioblastoma Biomarker for Cellular Metabolism Targeted Therapy.

Glioblastoma (GBM) is the most common and lethal type of primary malignant central nervous system (CNS) tumor with an extremely poor prognosis, and the mesenchymal subtype of GBM has the worst prognosis. Here, we found that lncRNA PRADX was overexpressed in the mesenchymal GBM and was transcriptionally regulated by RUNX1-CBFß complex, overexpressed PRADX suppressed BLCAP expression via interacting with EZH2 and catalyzing trimethylation of lysine 27 on histone H3 (H3K27me3). Moreover, we showed that BLCAP interacted with STAT3 and reduced STAT3 phosphorylation, overexpressed PRADX activated STAT3 phosphorylation, and promoted ACSL1 expression via suppressing BLCAP expression, accelerating tumor metabolism. Finally, we determined that combined of ACSL1 and CPT1 inhibitors could reverse the accelerated cellular metabolism and tumor growth induced by PRADX overexpression in vivo and in vitro. Collectively, PRADX/PRC2 complex activated the STAT3 pathway and energy metabolism in relation to mesenchymal GBM progression. Furthermore, our findings provided a novel therapeutic strategy targeting the energy metabolism activity of GBM.

RUNX1 (RUNX family transcription factor 1), a target of microRNA miR-128-3p, promotes temozolomide resistance in glioblastoma multiform by upregulating multidrug resistance-associated protein 1 (MRP1).

Glioblastoma multiform (GBM) is the most frequent type of malignant brain tumor with a poor prognosis. After optimal surgery, radiotherapy plus temozolomide (TMZ) is the standard treatment for GBM patients. However, the development of TMZ resistance limits its efficacy in GBM management. Runt Related Transcription Factor 1 (RUNX1) and microRNAs have been implicated in drug resistance of TMZ in GBM. In this study, we revealed the underlying mechanism of TMZ resistance and identified miR-128-3p/RUNX1 axis as a novel target for TMZ resistance in GBM. RUNX1 expression was significantly upregulated in GBM tissues as compared to normal tissues, and its expression was even higher in recurrent GBM tissues and TMZ-resistant GBM cells. RUNX1 depletion inhibited the viability, proliferation, migration, invasion and TMZ resistance of GBM cells, which could be rescued by RUNX1 overexpression. We further identified miR-128-3p as a tumor-suppressor whose overexpression restored the sensitivity of TMZ in GBM cells. miR-128-3p negatively regulated RUNX1 and subsequently downregulated multidrug resistance-associated protein 1 (MRP1). Together, the present study indicates that RUNX1 confers TMZ resistance in GBM by upregulating MRP1, which is negatively regulated by miR-128-3p. Targeting miR-128-3p/RUNX1/MRP1 axis provides a potential strategy to overcome TMZ resistance in GBM.

Combination LSD1 and HOTAIR-EZH2 inhibition disrupts cell cycle processes and induces apoptosis in glioblastoma cells.

Glioblastoma (GBM) is the most common primary central nervous system tumor and has a poor prognosis, with a median survival time of only 14 months from diagnosis. Abnormally expressed long noncoding RNAs (lncRNAs) are important epigenetic regulators of chromatin modification and gene expression regulation in tumors, including GBM. We previously showed that the lncRNA HOTAIR is related to the cell cycle progression and can be used as an independent predictor in GBM. Lysine-specific demethylase 1 (LSD1), binding to 3' domain of HOTAIR, specifically removes mono- and di-methyl marks from H3 lysine 4 (H3K4) and plays key roles during carcinogenesis. In this study, we combined a HOTAIR-EZH2 disrupting agent and an LSD1 inhibitor, AC1Q3QWB (AQB) and GSK-LSD1, respectively, to block the two functional domains of HOTAIR and potentially provide therapeutic benefit in the treatment of GBM. Using an Agilent Human ceRNA Microarray, we identified tumor suppressor genes upregulated by AQB and GSK-LSD1, followed by Chromatin immunoprecipitation (ChIP) assays to explore the epigenetic mechanisms of genes activation. Microarray analysis showed that AQB and GSK-LSD1 regulate cell cycle processes and induces apoptosis in GBM cell lines. Furthermore, we found that the combination of AQB and GSK-LSD1 showed a powerful effect of inhibiting cell cycle processes by targeting CDKN1A, whereas apoptosis promoting effects of combination therapy were mediated by BBC3 in vitro. ChIP assays revealed that GSK-LSD1 and AQB regulate P21 and PUMA, respectively via upregulating H3K4me2 and downregulating H3K27me3. Combination therapy with AQB and GSK-LSD1 on tumor malignancy in vitro and GBM patient-derived xenograft (PDX) models shows enhanced anti-tumor efficacy and appears to be a promising new strategy for GBM treatment through its effects on epigenetic regulation.

Identification and characterization of N6-methyladenosine modification of circRNAs in glioblastoma.

This research systematically profiled the global N6-methyladenosine modification pattern of circular RNAs (circRNAs) in glioblastoma (GBM). Based on RNA methylation sequencing (MeRIP sequencing or N6-methyladenosine sequencing) and RNA sequencing, we described the N6-methyladenosine modification status and gene expression of circRNAs in GBM and normal brain tissues. N6-methyladenosine-related circRNAs were immunoprecipitated and validated by real-time quantitative PCR. Bioinformatics analysis and related screening were carried out. Compared with those of the NC group, the circRNAs from GBM exhibited 1370 new N6-methyladenosine peaks and 1322 missing N6-methyladenosine peaks. Among the loci associated with altered N6-methyladenosine peaks, 1298 were up-regulated and 1905 were down-regulated. The N6-methyladenosine level tended to be positively correlated with circRNA expression. Bioinformatics analysis was used to predict the biological function of N6-methyladenosine-modified circRNAs and the corresponding signalling pathways. In addition, through PCR validation combined with clinical data mining, we identified five molecules of interest (BUB1, C1S, DTHD1, F13A1 and NDC80) that could be initial candidates for further study of the function and mechanism of N6-methyladenosine-mediated GBM development. In conclusion, our findings demonstrated the N6-methyladenosine modification pattern of circRNAs in human GBM, revealing the possible roles of N6-methyladenosine-mediated novel noncoding RNAs in the origin and progression of GBM.

Elastic-Modulus-Dependent Macroscopic Supramolecular Assembly of Poly(dimethylsiloxane) for Understanding Fast Interfacial Adhesion.

Macroscopic supramolecular assembly (MSA) is a new concept of supramolecular science with an emphasis on noncovalent interactions between macroscopic building blocks with sizes exceeding 10 µm. Owing to a similar noncovalently interactive nature with the phenomena of bioadhesion, self-healing, etc. and flexible features in tailoring and designing modular building blocks, MSA has been developed as a simplified model to interpret interfacial phenomena and a facile method to fabricate supramolecular materials. However, at this early stage, MSA has always been limited to hydrogel materials, which provide flowability for high molecular mobility to the interfacial binding. The extension to a wide range of materials for MSA is desired. Herein, we have developed a strategy of adjusting intrinsic properties (e.g., elastic modulus) of nonhydrogel materials to realize MSA, which could broaden the material choices of MSA. Using the widely used elastomer of poly(dimethylsiloxane) (PDMS) as building blocks, we have demonstrated the elastic-modulus-dependent MSA of PDMS based on the host/guest molecular recognition between supramolecular groups of ß-cyclodextrin and adamantane. In the varied elastic modulus range of 0.38 to 3.84 MPa, we obtained the trend of the MSA probability decreasing from 100% at 0.38 MPa to 0% at 3.84 MPa. Meanwhile, in situ measurements of interactive forces between PDMS building blocks have supported the observed assembly phenomena. The underlying reasons are interpreted with the low-modulus flexible surfaces favoring for high molecular mobility to achieve interactions between multiple sites at the interface based on the theory of multivalency. Taken together, we have demonstrated the feasibility of directly adjusting the modulus of bulk materials to realize MSA of nonhydrogel materials, which may provide clues to the fast wet adhesion and new solutions to the additive manufacture of elastomer materials.

PTRF/Cavin-1 as a Novel RNA-Binding Protein Expedites the NF-κB/PD-L1 Axis by Stabilizing lncRNA NEAT1, Contributing to Tumorigenesis and Immune Evasion in Glioblastoma.

Background: Immunotherapy, especially checkpoint inhibitors targeting PD-1 or PD-L1, has revolutionized cancer therapy. However, PD-1/PD-L1 inhibitors have not been investigated thoroughly in glioblastoma (GBM). Studies have shown that polymerase 1 and transcript release factor (PTRF/Cavin-1) has an immune-suppressive function in GBM. Thus, the relationship between PTRF and PD-L1 and their role in immune suppression requires further investigation in GBM. Methods: We used public databases and bioinformatics analysis to investigate the relationship between PTRF and PD-L1. We next confirmed the predicted relationship between PTRF and PD-L1 in primary GBM cell lines by using different experimental approaches. RIP-Seq, RIP, ChIP, and qRT-PCR were conducted to explore the molecular mechanism of PTRF in immunosuppression. Results: We found that PTRF stabilizes lncRNA NEAT1 to induce NF-κB and PD-L1 and promotes immune evasion in GBM. PTRF was found to correlate with immunosuppression in the public GBM databases. PTRF increased the level of PD-L1 in primary cell lines from GBM patients. We carried out RIP-Seq of GBM cells and found that PTRF interacts with lncRNA NEAT1 and stabilizes its mRNA. PTRF also promoted the activity of NF-κB by suppressing UBXN1 expression via NEAT1 and enhanced the transcription of PD-L1 through NF-κB activation. Finally, PTRF promoted immune evasion in GBM cells by regulating PD-1 binding and PD-L1 mediated T cell cytotoxicity. Conclusions: In summary, our study identified the PTRF-NEAT1-PD-L1 axis as a novel immune therapeutic target in GBM.