Inhibition of human glioblastoma cell invasion involves PION@E6 mediated autophagy process

Ferroptosis resistance in cancer cells: nanoparticles for combination therapy as a solution

Ferroptosis is a form of regulated cell death (RCD) characterized by iron-dependent lipid peroxidation. Ferroptosis is currently proposed as one of the most promising means of combating tumor resistance. Nevertheless, the problem of ferroptosis resistance in certain cancer cells has been identified. This review first, investigates the mechanisms of ferroptosis induction in cancer cells. Next, the problem of cancer cell resistance to ferroptosis, as well as the underlying mechanisms is discussed. Recently discovered ferroptosis-suppressing biomarkers have been described. The various types of nanoparticles that can induce ferroptosis are also discussed. Given the ability of nanoparticles to combine multiple agents, this review proposes nanoparticle-based ferroptosis cell death as a viable method of circumventing this resistance. This review suggests combining ferroptosis with other forms of cell death, such as apoptosis, cuproptosis and autophagy. It also suggests combining ferroptosis with immunotherapy.

Autophagy machinery in glioblastoma: The prospect of cell death crosstalk and drug resistance with bioinformatics analysis

Brain tumors are common malignancies with high mortality and morbidity in which glioblastoma (GB) is a grade IV astrocytoma with heterogeneous nature. The conventional therapeutics for the GB mainly include surgery and chemotherapy, however their efficacy has been compromised due to the aggressiveness of tumor cells. The dysregulation of cell death mechanisms, especially autophagy has been reported as a factor causing difficulties in cancer therapy. As a mechanism contributing to cell homeostasis, the autophagy process is hijacked by tumor cells for the purpose of aggravating cancer progression and drug resistance. The autophagy function is context-dependent and its role can be lethal or protective in cancer. The aim of the current paper is to highlight the role of autophagy in the regulation of GB progression. The cytotoxic function of autophagy can promote apoptosis and ferroptosis in GB cells and vice versa. Autophagy dysregulation can cause drug resistance and radioresistance in GB. Moreover, stemness can be regulated by autophagy and overall growth as well as metastasis are affected by autophagy. The various interventions including administration of synthetic/natural products and nanoplatforms can target autophagy. Therefore, autophagy can act as a promising target in GB therapy.

Improvement of synaptic plasticity by nanoparticles and the related mechanisms: Applications and prospects

Synaptic plasticity is an important basis of learning and memory and participates in brain network remodelling after different types of brain injury (such as that caused by neurodegenerative diseases, cerebral ischaemic injury, posttraumatic stress disorder (PTSD), and psychiatric disorders). Therefore, improving synaptic plasticity is particularly important for the treatment of nervous system-related diseases. With the rapid development of nanotechnology, increasing evidence has shown that nanoparticles (NPs) can cross the blood-brain barrier (BBB) in different ways, directly or indirectly act on nerve cells, regulate synaptic plasticity, and ultimately improve nerve function. Therefore, to better elucidate the effect of NPs on synaptic plasticity, we review evidence showing that NPs can improve synaptic plasticity by regulating different influencing factors, such as neurotransmitters, receptors, presynaptic membrane proteins and postsynaptic membrane proteins, and further discuss the possible mechanism by which NPs improve synaptic plasticity. We conclude that NPs can improve synaptic plasticity and restore the function of damaged nerves by inhibiting neuroinflammation and oxidative stress, inducing autophagy, and regulating ion channels on the cell membrane. By reviewing the mechanism by which NPs regulate synaptic plasticity and the applications of NPs for the treatment of neurological diseases, we also propose directions for future research in this field and provide an important reference for follow-up research.

LncRNA SOCS2-AS1 promotes the progression of glioma via regulating ITGB1 expression

BACKGROUND

Accumulating evidence has underscored the important role of long non-coding RNAs (lncRNAs) in the development and progression of glioma. However, the role of lncRNA SOCS2-AS1 in glioma is largely unknown.

METHODS

lncRNA SOCS2-AS1 silencing was achieved by specific siRNAs. Proliferation of glioma cell line after lncRNA SOCS2-AS1 silencing was examined by MTT assay, Transwell assay was used to confirm changes of invasion and migration of glioma cells, and study the molecular mechanism of lncRNA SOCS2-AS1 by RT-qPCR and bioinformatics analysis.

RESULTS

We identified that lncRNA SOCS2-AS1 was significantly upregulated in glioma, and its overexpression was closely related with malignant clinical features and poor prognosis. To explore the cellular function of SOCS2-AS1, we performed loss-of function assays in two glioma cells. We demonstrated that SOCS2-AS1 knockdown repressed glioma cell proliferation, migration and invasion. Mechanistically, SOCS2-AS1 expression was positively correlated with the expression levels of core factors ITGB1 of ECM-receptor interaction signaling pathway in glioma. Moreover, SOCS2-AS1 knockdown suppressed ITGB1 expression in glioma cells. Finally, rescue assays were carried out to determine that ITGB1 involved in SOCS2-AS1-mediated glioma cell proliferation, migration and invasion.

CONCLUSION

Our findings provided the first evidence suggested that SOCS2-AS1 promoted the progression of glioma via upregulating ITGB1 expression.

Ultrasmall iron oxide nanoparticles induced ferroptosis via Beclin1/ATG5-dependent autophagy pathway

Iron-based nanoparticles, which could elicit ferroptosis, is becoming a promising new way to inhibit tumor cell growth. Notably, ultrasmall iron oxide nanoparticles (USIONPs) have been found to upregulate the autophagy process in glioblastoma (GBM) cells. Whether USIONPs could also elicit ferroptosis and the relationship between the USIONPs-induced autophagy and ferroptosis need to be explored. In the current study, our synthesized USIONPs with good water solubility could significantly upregulate the ferroptosis markers in GBM cells, and downregulate the expression of anti-ferroptosis genes. Interestingly,ferrostatin-1 could reverse USIONPs- induced ferroptosis, but inhibitors of apoptosis, pyroptosis, or necrosis could not. Meanwhile, autophagy inhibitor 3-methyladenine could also reverse the USIONPs-induced ferroptosis. In addition, shRNA silencing of upstream genes Beclin1/ATG5 of autophagy process could significantly reverse USIONPs-induced ferroptosis, whereas overexpression of Beclin1/ATG5 of autophagy process could remarkably promote USIONPs-induced ferroptosis. Furthermore, lysosome inhibitors could significantly reverse the USIONPs-induced ferroptosis. Collectively, these facts suggest that USIONPs-induced ferroptosis is regulated via Beclin1/ATG5-dependent autophagy pathway.

Functional nanoassemblies for the diagnosis and therapy of Alzheimer's diseases

Alzheimer's disease (AD) is a progressive neurodegenerative disease that affects populations around the world. Many therapeutics have been investigated for AD diagnosis and/or therapy, but the efficacy is largely limited by the poor bioavailability of drugs and by the presence of the blood-brain barrier. Recently, the development of nanomedicines enables efficient drug delivery to the brain, but the complex pathological mechanism of AD prevents them from successful treatment. As a type of advanced nanomedicine, multifunctional nanoassemblies self-assembled from nanoscale imaging or therapeutic agents can simultaneously target multiple pathological factors, showing great potential in the diagnosis and therapy of AD. To help readers better understand this emerging field, in this review, we first introduce the pathological mechanisms and the potential drug candidates of AD, as well as the design strategies of nanoassemblies for improving AD targeting efficiency. Moreover, the progress of dynamic nanoassemblies that can diagnose and/or treat AD in response to the endogenous or exogenous stimuli will be described. Finally, we conclude with our perspectives on the future development in this field. The objective of this review is to outline the latest progress of using nanoassemblies to overcome the complex pathological environment of AD for improved diagnosis and therapy, in hopes of accelerating the future development of intelligent AD nanomedicines. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Diagnostic Tools > in vivo Nanodiagnostics and Imaging.

Quantitative Ultrastructural Morphometry and Gene Expression of mTOR-Related Mitochondriogenesis within Glioblastoma Cells

In glioblastoma (GBM) cells, an impairment of mitochondrial activity along with autophagy suppression occurs. Autophagy suppression in GBM promotes stemness, invasion, and poor prognosis. The autophagy deficit seems to be due, at least in part, to an abnormal up-regulation of the mammalian target of rapamycin (mTOR), which may be counteracted by pharmacological mTORC1 inhibition. Since autophagy activation is tightly bound to increased mitochondriogenesis, a defect in the synthesis of novel mitochondria is expected to occur in GBM cells. In an effort to measure a baseline deficit in mitochondria and promote mitochondriogenesis, the present study used two different GBM cell lines, both featuring mTOR hyperactivity. mTORC1 inhibition increases the expression of genes and proteins related to autophagy, mitophagy, and mitochondriogenesis. Autophagy activation was counted by RT-PCR of autophagy genes, LC3- immune-fluorescent puncta and immune-gold, as well as specific mitophagy-dependent BNIP3 stoichiometric increase in situ, within mitochondria. The activation of autophagy-related molecules and organelles after rapamycin exposure occurs concomitantly with progression of autophagosomes towards lysosomes. Remarkably, mitochondrial biogenesis and plasticity (increased mitochondrial number, integrity, and density as well as decreased mitochondrial area) was long- lasting for weeks following rapamycin withdrawal.

Repression of PCGF1 Decreases the Proliferation of Glioblastoma Cells in Association with Inactivation of c-Myc Signaling Pathway

Purpose

Glioblastoma (GBM) is the most common primary brain tumor with a poor therapeutic outcome. Polycomb group factor 1 (PCGF1), a member of the PcG (Polycomb group) family, is highly expressed in the developing nervous system of mice. However, the function and the mechanism of PCGF1 in GBM proliferation still remain unclear.

Methods

Knockdown of PCGF1 was performed in U87 GBM cell by shRNA strategy via lentivirus vector. MTT assay, colony formation assays, and flow cytometry were used to measure the properties of cell proliferation and cell cycle distribution, respectively. GeneChip analysis was performed to identify the downstream effector molecules. Rescue assay was constructed to verify the screening results.

Results

We first found that knockdown of PCGF1 led to the inhibition of U87 cells proliferation and decreased colony formation ability. The data from GeneChip expression profiling and Ingenuity Pathway Analysis (IPA) indicated that many of the altered gene cells are associated with the cell proliferation control pathways. We have further confirmed the suppression of AKT/GSK3β/c-Myc/cyclinD1 expressions by Western blotting analysis. The over-expression of c-Myc could partly restore the attenuated proliferation ability caused by knockdown of PCGF1.

Conclusion

All the above evidences suggested that PCGF1 might be closely associated with tumorigenesis and progression of glioblastoma (GBM), in which process the oncoprotein c-Myc may participate. PCGF1 could thus be a potential therapeutic target for the treatment of glioblastoma (GBM).

The dual roles of autophagy in gliomagenesis and clinical therapy strategies based on autophagic regulation mechanisms

Autophagy, a self-digestion intracellular catabolic process, plays a crucial role in cellular homeostasis under conditions of starvation, oxidative stress and genotoxic stress. The capability of maintaining homeostasis contributes to preventing malignant behavior in normal cells. Many studies have provided compelling evidence that autophagy is involved in brain tumor recurrence and chemotherapy and radiotherapy resistance. Gliomas, as the primary central nervous system (CNS) tumors, are characterized by rapid, aggressive growth and recurrence and have a poor prognosis and bleak outlook even with modern multimodality strategies involving maximal surgical resection, radiotherapy and alkylating agent-based chemotherapy. Autophagy-associated signaling pathways, such as the extracellular signal-regulated kinase1/2 (ERK1/2) pathway, class I phosphatidylinositol 3-phosphate kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway and nuclear factor kappa-B (NF-κB) pathway, act as tumor suppressors or protect tumor cells against chemotherapy/radiotherapy-induced cytotoxicity in gliomagenesis. Through these pathways, both lethal autophagy and protective autophagy play crucial roles in tumor initiation, chemoresistance and glioma stem cell differentiation. Moreover, lethal autophagy and protective autophagy have been identified as novel therapeutic targets in glioma according to the mechanisms described above. Here, we discuss the multiple impacts of the autophagic response on distinct phases of gliomagenesis and the advanced progress of therapies based on this concept.

Overexpression of HOXC6 promotes cell proliferation and migration via MAPK signaling and predicts a poor prognosis in glioblastoma

Background

Homeobox (HOX) genes encode transcription factors that are critical to morphogenesis and cell differentiation. Although the dysregulation of several HOX genes in glioblastoma (GBM) has been reported, little is known about HOXC6 expression in GBM. Therefore, in this study, we investigated the expression levels of the HOXC6 in GBM and explored the regulatory mechanism underlying the role of HOXC6 in GBM progression.

Methods

The ONCOMINE and Oncolnc databases were used to predict the expression level of HOXC6 mRNA and its prognostic value in GBM. The expressions of HOXC6 mRNA in GBM tissues and adjacent brain tissues were detected using qRT-PCR and Western blot. Immunohistochemistry was performed to verify the HOXC6 protein expression in 107 GBM tissues. Kaplan–Meier and Cox analyses were performed to validate the correlation between HOXC6 expression and GBM prognosis. Lentivirus-mediated HOXC6 mRNA overexpression and interference system were established and transfected into U251 and U87 cell lines. CCK-8, colony formation, wound healing and transwell assay were utilized to evaluate the effects of HOXC6 on proliferation and migration of human GBM cells.

Results

High expression of HOXC6 was observed in GBM tissues and GBM cells lines, and it correlated with a decreased overall survival and disease-free survival. Overexpression of HOXC6 promoted the GBM cell proliferation and migration, whereas depletion of HOXC6 reduced GBM cell proliferation and migration. Mechanistic study showed that upregulation of HOXC6 significantly increased the phosphorylation of Jun amino-terminal kinase, ERK and P38, as well as the expression of mitogen-activated protein kinase (MAPK) signaling–related genes, including c-myc, c-jun and p53. Inversely, silencing HOXC6 showed the opposite results.

Conclusion

HOXC6 promoted proliferation and migration of GBM cells via the activation of MAPK pathway.

LOX-1+ PMN-MDSC enhances immune suppression which promotes glioblastoma multiforme progression

Background/aims

Patients with glioblastoma multiforme (GBM) that is the most common brain cancer in adults have a rather poor prognosis. The accumulation of immune suppressive myeloid-derived suppressor cell (MDSC) is negatively associated with clinical outcomes in various cancers. A recent study identified that lectin-type oxidized LDL receptor 1 (LOX-1) may serve as a specific marker of human polymorphonuclear neutrophil (PMN)-MDSC. Thus, herein we focused on exploring the role of LOX-1+ PMN-MDSC in GBM progression.

Methods

LOX-1, IFN-γ, dichlorodihydrofluorescein diacetate (DCFDA), CD15, CD4 and CD8 expression levels were examined by flow cytometry. ARG1 and iNOS expression levels in PMN were examined by quantitative real-time PCR. LOX-1 and CD15 expression levels in tumor tissue were determined by immunofluorescent microscopy. T cell proliferation was determined by 3H-thymidine incorporation.

Results

We identified a protumorigenic subset of PMN, which constitutively expressed LOX-1 and accumulated in the peripheral blood of GBM patients. Compared to LOX-1− PMN, the LOX-1+ PMN exhibited a PMN MDSC profile, with a significant increase in the expression of DCFDA, ARG1 and iNOS, and the capacity of inhibiting the CD3+ T cell proliferation in a dependent-ARG1/iNOS way. Additionally, we found that LOX-1+ PMN negatively correlated with effector immune cells in GBM patients, accumulated in GBM tissues, and was related to early recurrence and disease progression tightly.

Conclusion

Our study revealed that LOX-1+ PMN-MDSC inhibited the T cell proliferation to enhance immune suppression, which may play a key role in driving the GBM progression.