Efficacy of EGFR plus TNF inhibition in a preclinical model of temozolomide-resistant glioblastoma

Application of EGFR-TKIs in brain tumors, a breakthrough in future?

Brain tumors, both primary and secondary, represent a significant clinical challenge due to their high mortality and limited treatment options. Primary brain tumors, such as gliomas and meningiomas, and brain metastases from cancers such as non-small cell lung cancer and breast cancer require innovative therapeutic strategies. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR -TKIs) have emerged as a promising treatment option, particularly for tumors harboring EGFR mutations. This review examines the use of EGFR-TKIs in brain tumors, highlighting both laboratory and clinical research findings. In primary brain tumors and brain metastases, EGFR-TKIs have shown potential in controlling tumor growth and improving patient outcomes. Advanced applications, such as nano-formulated EGFR-TKIs and combination therapies with other pathway inhibitors, are being investigated to improve efficacy and overcome resistance. Challenges such as treatment-related events, resistance mechanisms and blood-brain barrier penetration remain significant hurdles. Addressing tumor heterogeneity through personalized medicine approaches is critical to optimizing EGFR-TKI therapies. This review highlights the need for continued research to refine these therapies and improve survival for patients with brain tumors.

Cell death in glioblastoma and the central nervous system

Glioblastoma is the commonest and deadliest primary brain tumor. Glioblastoma is characterized by significant intra- and inter-tumoral heterogeneity, resistance to treatment and dismal prognoses despite decades of research in understanding its biological underpinnings. Encompassed within this heterogeneity and therapy resistance are severely dysregulated programmed cell death pathways. Glioblastomas recapitulate many neurodevelopmental and neural injury responses; in addition, glioblastoma cells are composed of multiple different transformed versions of CNS cell types. To obtain a greater understanding of the features underlying cell death regulation in glioblastoma, it is important to understand the control of cell death within the healthy CNS during homeostatic and neurodegenerative conditions. Herein, we review apoptotic control within neural stem cells, astrocytes, oligodendrocytes and neurons and compare them to glioblastoma apoptotic control. Specific focus is paid to the Inhibitor of Apoptosis proteins, which play key roles in neuroinflammation, CNS cell survival and gliomagenesis. This review will help in understanding glioblastoma as a transformed version of a heterogeneous organ composed of multiple varied cell types performing different functions and possessing different means of apoptotic control. Further, this review will help in developing more glioblastoma-specific treatment approaches and will better inform treatments looking at more direct brain delivery of therapeutic agents.

Novel strategies to overcome chemoresistance in human glioblastoma

Temozolomide (TMZ) is currently the first-line chemotherapeutic agent for the treatment of glioblastoma multiforme (GBM). However, the inherent heterogeneity of GBM often results in suboptimal outcomes, particularly due to varying degrees of resistance to TMZ. Over the past several decades, O6-methylguanine-DNA methyltransferase (MGMT)-mediated DNA repair pathway has been extensively investigated as a target to overcome TMZ resistance. Nonetheless, the combination of small molecule covalent MGMT inhibitors with TMZ and other chemotherapeutic agents has frequently led to adverse clinical effects. Recently, additional mechanisms contributing to TMZ resistance have been identified, including epidermal growth factor receptor (EGFR) mutations, overactivation of intracellular signalling pathways, energy metabolism reprogramming or survival autophagy, and changes in tumor microenvironment (TME). These findings suggest that novel therapeutic strategies targeting these mechanisms hold promise for overcoming TMZ resistance in GBM patients. In this review, we summarize the latest advancements in understanding the mechanisms underlying intrinsic and acquired TMZ resistance. Additionally, we compile various small-molecule compounds with potential to mitigate chemoresistance in GBM. These mechanism-based compounds may enhance the sensitivity of GBM to TMZ and related chemotherapeutic agents, thereby improving overall survival rates in clinical practice.

EGFR inhibits TNF-α-mediated pathway by phosphorylating TNFR1 at tyrosine 360 and 401

Tumour necrosis factor receptor 1 (TNFR1) induces the nuclear factor kappa-B (NF-κB) signalling pathway and regulated cell death processes when TNF-α ligates with it. Although mechanisms regulating the downstream pathways of TNFR1 have been elucidated, the direct regulation of TNFR1 itself is not well known. In this study, we showed that the kinase domain of the epidermal growth factor receptor (EGFR) regulates NF-κB signalling and TNF-α-induced cell death by directly phosphorylating TNFR1 at Tyr 360 and 401 in its death domain. In contrast, EGFR inhibition by EGFR inhibitors, such as erlotinib and gefitinib, prevented their interaction. Once TNFR1 is phosphorylated, its death domain induces the suppression of the NF-κB pathways, complex II-mediated apoptosis, or necrosome-dependent necroptosis. Physiologically, in mouse models, EGF treatment mitigates TNF-α-dependent necroptotic skin inflammation induced by treatment with IAP and caspase inhibitors. Our study revealed a novel role for EGFR in directly regulating TNF-α-related pathways.

Glioblastoma Standard of Care: Effects on Tumor Evolution and Reverse Translation in Preclinical Models

Glioblastoma (GBM) presents a significant public health challenge as the deadliest and most common malignant brain tumor in adults. Despite standard-of-care treatment, which includes surgery, radiation, and chemotherapy, mortality rates are high, underscoring the critical need for advancing GBM therapy. Over the past two decades, numerous clinical trials have been performed, yet only a small fraction demonstrated a benefit, raising concerns about the predictability of current preclinical models. Traditionally, preclinical studies utilize treatment-naïve tumors, failing to model the clinical scenario where patients undergo standard-of-care treatment prior to recurrence. Recurrent GBM generally exhibits distinct molecular alterations influenced by treatment selection pressures. In this review, we discuss the impact of treatment-surgery, radiation, and chemotherapy-on GBM. We also provide a summary of treatments used in preclinical models, advocating for their integration to enhance the translation of novel strategies to improve therapeutic outcomes in GBM.

Tumor suppressor role of the complement inhibitor CSMD1 and its role in TNF-induced neuroinflammation in gliomas

BACKGROUND

The complement inhibitor CSMD1 acts as a tumor suppressor in various types of solid cancers. Despite its high level of expression in the brain, its function in gliomas, malignant brain tumors originating from glial cells, has not been investigated.

METHODS

Three cohorts of glioma patients comprising 1500 patients were analyzed in our study along with their clinical data. H4, U-118 and U-87 cell lines were used to investigate the tumor suppressor function of CSMD1 in gliomas. PDGFB-induced brain tumor model was utilized for the validation of in vitro data.

RESULTS

The downregulation of CSMD1 expression correlated with reduced overall and disease-free survival, elevated tumor grade, wild-type IDH genotype, and intact 1p/19q status. Moreover, enhanced activity was noted in the neuroinflammation pathway. Importantly, ectopic expression of CSMD1 in glioma cell lines led to decreased aggressiveness in vitro. Mechanically, CSMD1 obstructed the TNF-induced NF-kB and STAT3 signaling pathways, effectively suppressing the secretion of IL-6 and IL-8. There was also reduced survival in PDGFB-induced brain tumors in mice when Csmd1 was downregulated.

CONCLUSIONS

Our study has identified CSMD1 as a tumor suppressor in gliomas and elucidated its role in TNF-induced neuroinflammation, contributing to a deeper understanding of glioma pathogenesis.

The Role of Progranulin (PGRN) in the Pathogenesis of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) represents the most common and aggressive malignant form of brain tumour in adults and is characterized by an extremely poor prognosis with dismal survival rates. Currently, expanding concepts concerning the pathophysiology of GBM are inextricably linked with neuroinflammatory phenomena. On account of this fact, the identification of novel pathomechanisms targeting neuroinflammation seems to be crucial in terms of yielding successful individual therapeutic strategies. In recent years, the pleiotropic growth factor progranulin (PGRN) has attracted significant attention in the neuroscience and oncological community regarding its neuroimmunomodulatory and oncogenic functions. This review of the literature summarizes and updates contemporary knowledge about PGRN, its associated receptors and signalling pathway involvement in GBM pathogenesis, indicating possible cellular and molecular mechanisms with potential diagnostic, prognostic and therapeutic targets in order to yield successful individual therapeutic strategies. After a review of the literature, we found that there are possible PGRN-targeted therapeutic approaches for implementation in GBM treatment algorithms both in preclinical and future clinical studies. Furthermore, PGRN-targeted therapies exerted their highest efficacy in combination with other established chemotherapeutic agents, such as temozolomide. The results of the analysis suggested that the possible implementation of routine determinations of PGRN and its associated receptors in tumour tissue and biofluids could serve as a diagnostic and prognostic biomarker of GBM. Furthermore, promising preclinical applications of PGRN-related findings should be investigated in clinical studies in order to create new diagnostic and therapeutic algorithms for GBM treatment.

Preclinical Efficacy of LP-184, a Tumor Site Activated Synthetic Lethal Therapeutic, in Glioblastoma

PURPOSE

Glioblastoma (GBM) is the most common brain malignancy with median survival <2 years. Standard-of-care temozolomide has marginal efficacy in approximately 70% of patients due to MGMT expression. LP-184 is an acylfulvene-derived prodrug activated by the oxidoreductase PTGR1 that alkylates at N3-adenine, not reported to be repaired by MGMT. This article examines LP-184 efficacy against preclinical GBM models and identifies molecular predictors of LP-184 efficacy in clinical GBM.

EXPERIMENTAL DESIGN

LP-184 effects on GBM cell viability and DNA damage were determined using cell lines, primary PDX-derived cells and patient-derived neurospheres. GBM cell sensitivities to LP-184 relative to temozolomide and MGMT expression were examined. Pharmacokinetics and CNS bioavailability were evaluated in mice with GBM xenografts. LP-184 effects on GBM xenograft growth and animal survival were determined. Machine learning, bioinformatic tools, and clinical databases identified molecular predictors of GBM cells and tumors to LP-184 responsiveness.

RESULTS

LP-184 inhibited viability of multiple GBM cell isolates including temozolomide-resistant and MGMT-expressing cells at IC50 = approximately 22-310 nmol/L. Pharmacokinetics showed favorable AUCbrain/plasma and AUCtumor/plasma ratios of 0.11 (brain Cmax = 839 nmol/L) and 0.2 (tumor Cmax = 2,530 nmol/L), respectively. LP-184 induced regression of GBM xenografts and prolonged survival of mice bearing orthotopic xenografts. Bioinformatic analyses identified PTGR1 elevation in clinical GBM subtypes and associated LP-184 sensitivity with EGFR signaling, low nucleotide excision repair (NER), and low ERCC3 expression. Spironolactone, which induces ERCC3 degradation, decreased LP-184 IC50 3 to 6 fold and enhanced GBM xenograft antitumor responses.

CONCLUSIONS

These results establish LP-184 as a promising chemotherapeutic for GBM with enhanced efficacy in intrinsic or spironolactone-induced TC-NER-deficient tumors.

EGFR-TNFR1 pathway in endothelial cell facilitates acute lung injury by NF-κB/MAPK-mediated inflammation and RIP3-dependent necroptosis

Tumor necrosis factor-α (TNFα) has emerged as a pivotal effector critically correlated with disease severity in acute lung injury (ALI). Because both the excessive activation of epidermal growth factor receptor (EGFR) and tumor necrosis factor receptor 1 (TNFR1) in sepsis-induced vasculitis are markedly diminished through EGFR tyrosine kinase inhibitor, a specific mechanism must exist to modulate TNFR1 cellular fates regulated by EGFR. Here, we demonstrated that EGFR, a specific binding partner of TNFR1, exhibited an increased NF-κB/MAPK-mediated inflammation that was governed by enhanced recruitment of TNFR-associated factor 2 (TRAF2) to TNFR1 complex I in endothelial cell (EC). Moreover, EGFR activation triggered a remarkable increase in the phosphorylation of receptor-interacting protein 1 (RIP1) and its binding with receptor-interacting protein 3 (RIP3) which led to enhanced frequency of necroptosis in complex IIb. Inhibiting the kinase of EGFR disrupted the formation of complex I and complex IIb and prevents EC from NF-κB/MAPK-mediated inflammation and RIP3-dependent necroptosis. Consistently, pharmacological inhibition of EGFR can limit the destructive effects of neutrophils activation and the hyperpermeability of lung vascular in hyperinflammation period. Collectively, we have identified EC-EGFR as a modulator of TNFR1-mediated inflammation and RIP3-dependent necroptosis, providing a possible explanation for the immunological basis of anti-EGFR therapy in sepsis-induced ALI.

EGFR ligand shifts the role of EGFR from oncogene to tumour suppressor in EGFR-amplified glioblastoma by suppressing invasion through BIN3 upregulation

The epidermal growth factor receptor (EGFR) is a prime oncogene that is frequently amplified in glioblastomas. Here we demonstrate a new tumour-suppressive function of EGFR in EGFR-amplified glioblastomas regulated by EGFR ligands. Constitutive EGFR signalling promotes invasion via activation of a TAB1-TAK1-NF-κB-EMP1 pathway, resulting in large tumours and decreased survival in orthotopic models. Ligand-activated EGFR promotes proliferation and surprisingly suppresses invasion by upregulating BIN3, which inhibits a DOCK7-regulated Rho GTPase pathway, resulting in small hyperproliferating non-invasive tumours and improved survival. Data from The Cancer Genome Atlas reveal that in EGFR-amplified glioblastomas, a low level of EGFR ligands confers a worse prognosis, whereas a high level of EGFR ligands confers an improved prognosis. Thus, increased EGFR ligand levels shift the role of EGFR from oncogene to tumour suppressor in EGFR-amplified glioblastomas by suppressing invasion. The tumour-suppressive function of EGFR can be activated therapeutically using tofacitinib, which suppresses invasion by increasing EGFR ligand levels and upregulating BIN3.

A Novel TNFSF-Based Signature Predicts the Prognosis and Immunosuppressive Status of Lower-Grade Glioma

Purpose

Tumour necrosis factor (TNF) superfamilies play important roles in cell proliferation, migration, differentiation, and apoptosis. We believe that TNF has a huge potential and might cast new insight into antitumour therapies. Therefore, we established this signature based on TNF superfamilies.

Results

A six-gene signature derived from the TNF superfamilies was established. The Riskscore correlated significantly with the expression of immune checkpoint genes and infiltrating M2 macrophages in the tumour specimen. This signature was also associated with mutations in genes that regulate tumour cell proliferation. Univariate and multivariate regression analyses further confirmed the Riskscore, TNFRSF11b, and TNFRSF12a as independent risk factors in The Cancer Genome Atlas and Chinese Glioma Genome Atlas datasets.

Conclusion

Our signature could accurately predict the prognosis of lower-grade gliomas (LGG). In addition, this six-gene signature could predict the immunosuppressive status of LGG and provide evidence that TNF superfamilies had correlations with some critical mutations that could be effectively targeted now.

To Explore the Stem Cells Homing to GBM: The Rise to the Occasion

Multiple efforts are currently underway to develop targeted therapeutic deliveries to the site of glioblastoma progression. The use of carriers represents advancement in the delivery of various therapeutic agents as a new approach in neuro-oncology. Mesenchymal stem cells (MSCs) and neural stem cells (NSCs) are used because of their capability in migrating and delivering therapeutic payloads to tumors. Two of the main properties that carrier cells should possess are their ability to specifically migrate from the bloodstream and low immunogenicity. In this article, we also compared the morphological and molecular features of each type of stem cell that underlie their migration capacity to glioblastoma. Thus, the major focus of the current review is on proteins and lipid molecules that are released by GBM to attract stem cells.

Gas Plasma Exposure of Glioblastoma Is Cytotoxic and Immunomodulatory in Patient-Derived GBM Tissue

Simple Summary

Despite treatment advances, glioblastoma multiforme (GBM) remains an often-fatal disease, motivating novel therapeutic avenues. Gas plasma is a technology that has been recently employed in preclinical oncology research and acts primarily via reactive oxygen-species-induced cell death. In addition, the modulation of immune processes and inflammation have been ascribed to gas plasma exposure. This is the first study that extends those observations from in vitro investigations to a set of 16 patient-derived GBM tumor biopsies analyzed after gas plasma treatment ex vivo. Besides cell culture results showing cell cycle arrest and apoptosis induction, an immunomodulatory potential was identified for gas plasma exposure in vitro and cultured GBM tissues. The proapoptotic action shown in this study might be an important step forward to the first clinical observational studies on the future discovery of gas plasma technology’s potential in neurosurgery and neuro-oncology.

Abstract

Glioblastoma multiforme (GBM) is the most common primary malignant adult brain tumor. Therapeutic options for glioblastoma are maximal surgical resection, chemotherapy, and radiotherapy. Therapy resistance and tumor recurrence demand, however, new strategies. Several experimental studies have suggested gas plasma technology, a partially ionized gas that generates a potent mixture of reactive oxygen species (ROS), as a future complement to the existing treatment arsenal. However, aspects such as immunomodulation, inflammatory consequences, and feasibility studies using GBM tissue have not been addressed so far. In vitro, gas plasma generated ROS that oxidized cells and led to a treatment time-dependent metabolic activity decline and G2 cell cycle arrest. In addition, peripheral blood-derived monocytes were co-cultured with glioblastoma cells, and immunomodulatory surface expression markers and cytokine release were screened. Gas plasma treatment of either cell type, for instance, decreased the expression of the M2-macrophage marker CD163 and the tolerogenic molecule SIGLEC1 (CD169). In patient-derived GBM tissue samples exposed to the plasma jet kINPen ex vivo, apoptosis was significantly increased. Quantitative chemokine/cytokine release screening revealed gas plasma exposure to significantly decrease 5 out of 11 tested chemokines and cytokines, namely IL-6, TGF-β, sTREM-2, b-NGF, and TNF-α involved in GBM apoptosis and immunomodulation. In summary, the immuno-modulatory and proapoptotic action shown in this study might be an important step forward to first clinical observational studies on the future discovery of gas plasma technology’s potential in neurosurgery and neuro-oncology especially in putative adjuvant or combinatory GBM treatment settings.

Molecular characteristics of single patient-derived glioma stem-like cells from primary and recurrent glioblastoma

Glioblastoma has high recurrence, while the sensitivity of recurrent glioblastoma to chemotherapy is lower than that of primary glioblastoma. Moreover, there is no standardized treatment for recurrent glioblastoma. Unfortunately, the biological mechanism of recurrent glioblastoma is still unclear, and there are few related studies. We compared the phenotypes of clinical glioblastoma specimens, in-vitro cultured glioma stem-like cells (GSCs) and patient-derived xenograft tumor (PDX) models to explore the molecular genetic characteristics of primary and recurrent glioblastoma from the same patient. In vitro, SU5-2, GSCs derived from recurrent glioblastoma specimens, had stronger proliferative activity and self-renewal ability. Meanwhile, SU5-2 was more resistant to temozolomide and invasive than SU5-1, which derived from primary glioblastoma specimens. Further analysis of the expression of costimulatory molecules showed that the expression of B7-H1, B7-H2 and B7-H3 of SU5-2 were upregulated. In vivo, Kaplan-Meier survival curve analysis showed that the median survival of the recurrent PDX group was worse. The results of gene detection in vitro, PDX model and clinical samples were consistent. Our results showed that the GSCs based on glioblastoma specimens and the PDX models could replicate the main molecular genetic characteristics of original tumors, which provided a reliable experimental platform for both tumor translation kinds of research and screening of molecular therapeutic targets.

Comprehensive targeting of resistance to inhibition of RTK signaling pathways by using glucocorticoids

Inhibition of RTK pathways in cancer triggers an adaptive response that promotes therapeutic resistance. Because the adaptive response is multifaceted, the optimal approach to blunting it remains undetermined. TNF upregulation is a biologically significant response to EGFR inhibition in NSCLC. Here, we compared a specific TNF inhibitor (etanercept) to thalidomide and prednisone, two drugs that block TNF and also other inflammatory pathways. Prednisone is significantly more effective in suppressing EGFR inhibition-induced inflammatory signals. Remarkably, prednisone induces a shutdown of bypass RTK signaling and inhibits key resistance signals such as STAT3, YAP and TNF-NF-κB. Combined with EGFR inhibition, prednisone is significantly superior to etanercept or thalidomide in durably suppressing tumor growth in multiple mouse models, indicating that a broad suppression of adaptive signals is more effective than blocking a single component. We identify prednisone as a drug that can effectively inhibit adaptive resistance with acceptable toxicity in NSCLC and other cancers.

EGR1 modulated LncRNA HNF1A-AS1 drives glioblastoma progression via miR-22-3p/ENO1 axis

Accumulating evidences revealed that long noncoding RNAs (lncRNAs) have been participated in cancer malignant progression, including glioblastoma multiforme (GBM). Despite much studies have found the precise biological role in the regulatory mechanisms of GBM, however the molecular mechanisms, particularly upstream mechanisms still need further elucidated. RT-QPCR, cell transfection, western blotting and bioinformatic analysis were executed to detect the expression of EGR1, HNF1A-AS1, miR-22-3p and ENO1 in GBM. Cell proliferation assay, colony formation assay, wound healing, migration and invasion assays were performed to detect the malignant characters of GBM cells. The molecular regulation mechanism was confirmed by luciferase reporter assay, ChIP and RIP. Finally, orthotopic mouse models were established to examine the effect of HNF1A-AS1 in vivo. In the current study, we analyzed clinical samples to show that the HNF1A-AS1 expression is upregulated and associated with poor patient survival in GBM. Functional studies revealed that HNF1A-AS1 knockdown markedly inhibits malignant phenotypes of GBM cells, whereas overexpression of HNF1A-AS1 exerts opposite effect. Mechanistically, the transcription factor EGR1 forced the HNF1A-AS1 expression by directly binding the promoter region of HNF1A-AS1. Furthermore, combined bioinformatics analysis with our mechanistic work, using luciferase reporter assays and RIP, we first demonstrated that HNF1A-AS1 functions as a competing endogenous RNA (ceRNA) with miR-22-3p to regulate ENO1 expression in GBM cells. HNF1A-AS1 directly binds to miR-22-3p and significantly inhibits miR-22-3p expression, while ENO1 expression was increased. miR-22-3p inhibitor offsets the HNF1A-AS1 silencing induced suppression in malignant behaviors of GBM cells. ENO1 was verified as a direct target of miR-22-3p and its expression levels was negatively with the prognosis in GBM patients. Taken together, our study illuminated the definite mechanism of HNF1A-AS1 in promoting GBM malignancy, and provided a novel therapeutic target for further clinical application.

METTL3 Promotes the Resistance of Glioma to Temozolomide via Increasing MGMT and ANPG in a m6A Dependent Manner

Acquired chemoresistance is a major limiting factor in the clinical treatment of glioblastoma (GBM). However, the mechanism by which GBM acquires therapeutic resistance remains unclear. Here, we aimed to investigate whether METTL3-mediated N6-methyladenosine (m⁶A) modification contributes to the temozolomide (TMZ) resistance in GBM. We demonstrated that METTL3 METTL3-mediated m⁶A modification were significantly elevated in TMZ-resistant GBM cells. Functionally, METTL3 overexpression impaired the TMZ-sensitivity of GBM cells. In contrast, METTL3 silencing or DAA-mediated total methylation inhibition improved the sensitivity of TMZ-resistant GBM cells to TMZ in vitro and in vivo. Furthermore, we found that two critical DNA repair genes (MGMT and APNG) were m⁶A-modified by METTL3, whereas inhibited by METTL3 silencing or DAA-mediated total methylation inhibition, which is crucial for METTL3-improved TMZ resistance in GBM cells. Collectively, METTL3 acts as a critical promoter of TMZ resistance in glioma and extends the current understanding of m⁶A related signaling, thereby providing new insights into the field of glioma treatment.

TNF-α released from retinal Müller cells aggravates retinal pigment epithelium cell apoptosis by upregulating mitophagy during diabetic retinopathy

Retinal pigment epithelium (RPE) cell damage, including mitophagy-associated cell apoptosis, accelerates the pathogenesis of diabetic retinopathy (DR), a common complication of diabetes that causes blindness. Müller cells interact with RPE cells via pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α). Herein, we investigated the role of the RPE cell epidermal growth factor receptor (EGFR)/p38 mitogen-activated protein kinase (p38)/nuclear factor kappa B (NF-κB) pathway in Müller cell-derived TNF-α-induced mitophagy-associated apoptosis during DR. Our results showed that TNF-α released from Müller cells activated the EGFR/p38/NF-κB/p62 pathway to increase mitophagy and apoptosis in RPE cells under high glucose (HG) conditions. Additionally, blockade of the TNF-α/EGFR axis alleviates blood-retina barrier breakdown in diabetic mice. Our data further illustrate the effects of the Müller cell inflammatory response on RPE cell survival, implying potential molecular targets for DR treatment.

4-Acetylantrocamol LT3 Inhibits Glioblastoma Cell Growth and Downregulates DNA Repair Enzyme O6-Methylguanine-DNA Methyltransferase

Glioblastoma multiforme (GBM) is a deadly malignant brain tumor that is resistant to most clinical treatments. Novel therapeutic agents that are effective against GBM are required. Antrodia cinnamomea has shown antiproliferative effects in GBM cells. However, the exact mechanisms and bioactive components remain unclear. Thus, the present study aimed to investigate the effect and mechanism of 4-acetylantrocamol LT3 (4AALT3), a new ubiquinone from Antrodia cinnamomeamycelium, in vitro. U87 and U251 cell lines were treated with the indicated concentration of 4AALT3. Cell viability, cell colony-forming ability, migration, and the expression of proteins in well-known signaling pathways involved in the malignant properties of glioblastoma were then analyzed by CCK-8, colony formation, wound healing, and western blotting assays, respectively. We found that 4AALT3 significantly decreased cell viability, colony formation, and cell migration in both in vitro models. The epidermal growth factor receptor (EGFR), phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR), Hippo/yes-associated protein (YAP), and cAMP-response element binding protein (CREB) pathways were suppressed by 4AALT3. Moreover, 4AALT3 decreased the level of DNA repair enzyme O⁶-methylguanine-DNA methyltransferase and showed a synergistic effect with temozolomide. Our findings provide the basis for exploring the beneficial effect of 4AALT3 on GBM in vivo.

Tumor necrosis factor in lung cancer: Complex roles in biology and resistance to treatment

Tumor necrosis factor (TNF) and its receptors are widely expressed in non-small cell lung cancer (NSCLC). TNF has an established role in inflammation and also plays a key role in inflammation-induced cancer. TNF can induce cell death in cancer cells and has been used as a treatment in certain types of cancer. However, TNF is likely to play an oncogenic role in multiple types of cancer, including NSCLC. TNF is a key activator of the transcription factor NF-κB. NF-κB, in turn, is a key effector of TNF in inflammation-induced cancer. Data from The Cancer Genome Atlas database suggest that TNF could be a biomarker in NSCLC and indicate a complex role for TNF and its receptors in NSCLC. Recent studies have reported that TNF is rapidly upregulated in NSCLC in response to targeted treatment with epidermal growth factor receptor (EGFR) inhibition, and this upregulation leads to NF-κB activation. The TNF upregulation and consequent NF-κB activation play a key role in mediating both primary and secondary resistance to EGFR inhibition in NSCLC, and a combined inhibition of EGFR and TNF can overcome therapeutic resistance in experimental models. TNF may mediate the toxic side effects of immunotherapy and may also modulate resistance to immune checkpoint inhibitors. Drugs inhibiting TNF are widely used for the treatment of various inflammatory and rheumatologic diseases and could be quite useful in combination with targeted therapy of NSCLC and other cancers.

Natural substances to potentiate canonical glioblastoma chemotherapy

Glioblastoma multiforme (GBM) is the most frequent primary malignant brain tumour prevalent in humans, that exhibits aggressive cell proliferation and rapid invasion of normal brain tissue. Despite aggressive therapeutic approaches consisting of maximum safe surgical resection followed by radio-chemotherapy with temozolomide (TMZ), more than 95% of GBM patients die within 5 years after diagnosis. In most cases, the therapy is not able to counteract the growth and invasiveness of the tumour, which relapses after an interval of time that varies from patient to patient. An increasing number of evidence indicates that natural substances exhibited effective anti-tumour functions and might be successfully used in the treatment of GBM. This review summarizes some natural substances: lactoferrin, hispolon, aloe-emodin and tea tree oil; all these show a growth inhibition and synergistic effect when together with TMZ, (the most commonly used alkylating drug for the treatment of glioblastoma) were administered to U87MG glioblastoma cell line in vitro and in murine animal model. U87MG cell growth was monitored by daily cell count after treatments with the substances mentioned above and growth analysis showed that all drugs significantly decrease proliferation of U87MG in a time- and dose-dependent manner. FACS analysis demonstrates a block of cell cycle in S, G2/M or G0/G1 phases. These substances mediate multiple processes including apoptosis by releasing the inducing factor: PARP. Natural compounds, in combination with conventional chemotherapy TMZ, are a powerful approach to improve the effectiveness of brain cancer treatment.

Computational analysis and verification of molecular genetic targets for glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most common malignant brain tumor with a poor prognosis. The initial treatment for high-grade gliomas is surgical excision. However, even with concomitant use of radiation or chemotherapy, patients are still prone to recurrence. The specific pathogenesis of GBM is still controversial.

METHODS

Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) between GBM and normal brain tissues were screened. P-value was obtained by Bayes test based on the limma package. Statistical significance was set as P-value <0.05 and |Fold change (FC)| > 0.2 (GSE90886); P-value <0.05 and |FC| > 1 (GSE116520, GSE103228). Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI) network were performed. Hub genes were selected from miRNA target genes and DEGs. GBM and normal brain tissues were extracted to verify the expression.

RESULTS

A total of 100 DEGs were overlapped in both datasets. Analysis of pathways and process enrichment tests indicated that ion transport, positive regulation of macromolecule metabolic process, cell cycle, axon guidance were enriched in the GBM. Sixteen hub genes were identified. Hub genes ADARB1 and neuropilin 1 (NRP1) were significantly associated with overall survival (OS) and disease-free survival (DFS) (P<0.05). Eukaryotic translation termination factor 1 (ETF1) was associated with DFS (P<0.05).

CONCLUSIONS

DEGs and DEMs were found between GBM tumor tissues and normal brain tissues. These biomarkers may be used as targets for early diagnosis and specific treatment.

EGFR inhibition triggers an adaptive response by co-opting antiviral signaling pathways in lung cancer

EGFR inhibition is an effective treatment in the minority of non-small cell lung cancer (NSCLC) cases harboring EGFR-activating mutations, but not in EGFR wild type (EGFRwt) tumors. Here, we demonstrate that EGFR inhibition triggers an antiviral defense pathway in NSCLC. Inhibiting mutant EGFR triggers Type I IFN-I upregulation via a RIG-I-TBK1-IRF3 pathway. The ubiquitin ligase TRIM32 associates with TBK1 upon EGFR inhibition, and is required for K63-linked ubiquitination and TBK1 activation. Inhibiting EGFRwt upregulates interferons via an NF-κB-dependent pathway. Inhibition of IFN signaling enhances EGFR-TKI sensitivity in EGFR mutant NSCLC and renders EGFRwt/KRAS mutant NSCLC sensitive to EGFR inhibition in xenograft and immunocompetent mouse models. Furthermore, NSCLC tumors with decreased IFN-I expression are more responsive to EGFR TKI treatment. We propose that IFN-I signaling is a major determinant of EGFR-TKI sensitivity in NSCLC and that a combination of EGFR TKI plus IFN-neutralizing antibody could be useful in most NSCLC patients.