Expression of mTOR in normal and pathological conditions

Mir-615-3p promotes osteosarcoma progression via the SESN2/AMPK/mTOR pathway

BACKGROUND

Osteosarcoma (OS) is the most common primary malignant bone neoplasm. Growing researches have highlighted the tumor promoting role of miR-615-3p in various cancers. Notwithstanding, the biological function and underlying mechanisms of miR-615-3p in OS development still unclear.

METHODS

Quantitative Real-Time PCR analysis (qRT-PCR) and RNA fluorescence in situ hybridization (FISH) staining were performed to measure miR-615-3p expression in OS. CCK-8 assay, colony formation assay and EdU assay were applied to analyze the OS cell proliferation activity. Cell metastasis abilities were evaluated using Transwell assays. Analysis of apoptosis was performed based on flow cytometric detection. The potential mechanisms of miR-615-3p in OS progression were investigated through RNA immunoprecipitation (RIP) assays, dual-luciferase reporter assays, qRT-PCR and western blotting. In vivo experiments, mouse xenograft model was carried out to assess the tumorigenicity of miR-615-3p.

RESULTS

This study demonstrated a significant upregulation of miR-615-3p in OS. In addition, miR-615-3p knockdown suppressed OS proliferation, invasion, metastasis and EMT. Mechanistically, miR-615-3p regulated sestrin 2 (SESN2) expression negatively by targeting its 3'UTR. Moreover, silencing SESN2 facilitated OS progression and activated mTOR pathway. Noteworthy, the anticancer functions of miR-615-3p knockdown were partially recovered by SESN2 silencing. Taken together, the miR-615-3p/SESN2/mTOR pathway is critical for regulating OS progression.

CONCLUSION

Our results revealed that miR-615-3p modulated mTOR signaling, thus influencing the progression of OS. For OS treatment, molecular strategies that target the miR-615-3p/SESN2/mTOR pathway is promising.

Capecitabine mitigates cardiac allograft rejection via inhibition of TYMS-Mediated Th1 differentiation in mice

OBJECTIVES

Previous studies elucidated that capecitabine (CAP) works as an anti-tumor agent with putative immunosuppressive effects. However, the intricate mechanisms underpinning these effects remain to be elucidated. In this study, we aimed to unravel the molecular pathways by which CAP exerts its immunosuppressive effects to reduce allograft rejection.

METHODS

Hearts were transplanted from male BALB/c donors to male C57BL/6 recipients and treated with CAP for seven days. The rejection of these heart transplants was assessed using a range of techniques, including H&E staining, immunohistochemistry, RNA sequencing, LS-MS/MS, and flow cytometry. In vitro, naïve CD4+ T cells were isolated and cultured under Th1 condition medium with varying treatments, flow cytometry, LS-MS/MS were employed to delineate the role of thymidine synthase (TYMS) during Th1 differentiation.

RESULTS

CAP treatment significantly mitigated acute allograft rejection and enhanced graft survival by reducing graft damage, T cell infiltration, and levels of circulating pro-inflammatory cytokines. Additionally, it curtailed CD4+ T cell proliferation and the presence of Th1 cells in the spleen. RNA-seq showed that TYMS, the target of CAP, was robustly increased post-transplantation in splenocytes. In vitro, TYMS and its metabolic product dTMP were differentially expressed in Th0 and Th1, and were required after activation of CD4+ T cell and Th1 differentiation. TYMS-specific inhibitor, raltitrexed, and the metabolite of capecitabine, 5-fluorouracil, could inhibit the proliferation and differentiation of Th1. Finally, the combined use of CAP and the commonly used immunosuppressant rapamycin can induce long-term survival of allograft.

CONCLUSION

CAP undergoes metabolism conversion to interfere pyrimidine metabolism, which targets TYMS-mediated differentiation of Th1, thereby playing a significant role in mitigating acute cardiac allograft rejection in murine models.

miRNA375-3p/rapamycin mediates the mTOR pathway by decreasing PS1, enhances microglial cell activity to regulate autophagy in Alzheimer's disease

The clinical prevention, diagnosis, treatment, and drug development of Alzheimer's disease (AD) require urgent detection of novel targets and methods. Autophagy and microglia are significantly associated with the pathogenesis of early AD. This study indicated that microRNA-375-3p can inhibit autophagy by promoting mTOR phosphorylation in normal physiological conditions, while microRNA-375-3p promoted autophagy and enhanced neural repair by inhibiting the expression of presenilin 1 in early AD pathogenesis. Furthermore, co-treatment of rapamycin, and microRNA-375-3p can synergistically promote the autophagy and microglial activation in a neuroprotective manner, clear Aβ accumulation, repair nerve damage, and alleviate cognitive dysfunction and memory defects in APP/PS1 TG mice. This research revealed the impact and mechanism of miR375-3p on the early stage of AD through in vivo and in vitro experiments and provides new ideas and directions for the early treatment of AD.

Arf1 promotes porcine intestinal epithelial cell proliferation via the mTORC1 signaling pathway

The promotion of gut health, a pervasive problem in modern animal husbandry, positively affects organismal health, productivity, and economics. Porcine intestinal epithelial cells (IPEC-J2) continuously proliferate to maintain intestinal homeostasis, including barrier, immune, and absorptive functions. Gut homeostasis is fundamental to organismal health. ADP-ribosylation factor 1 (Arf1), a small GTPase, plays a crucial role in coordinating mTORC1 in response to nutrients, especially amino acid availability in the gut. mTORC1 is the central hub of proliferation. Thus, it seems likely that Arf1 promotes IPEC-J2 cell proliferation. However, the exact role of Arf1 in the porcine gut remains unclear. Therefore, we evaluated the functional role and possible mechanisms of Arf1 in the porcine intestine through Arf1 overexpression and knockdown in IPEC-J2 cells. Arf1 overexpression and knockdown significantly enhanced and inhibited, respectively, IPEC-J2 cell viability, and PCNA expression varied with Arf1 expression. Moreover, the proportion of Ki67-positive cells was significantly greater in the Arf1-overexpressing group than in the control group. These results suggest that Arf1 improves IPEC-J2 cell proliferation. The underlying mechanism was explored by Western blotting. Arf1 overexpression and knockdown significantly enhanced and suppressed, respectively, the levels of p-S6K1 and p-RPS6, which are key downstream targets of the mTORC1 signaling pathway. Collectively, our findings reveal the role of the Arf1-mTORC1 axis in IPEC-J2 cell proliferation and its potential function in regulating intestinal homeostasis and health.

A rationally designed CD19 monoclonal antibody-triptolide conjugate for the treatment of systemic lupus erythematosus

Tripterygium wilfordii Hook F (TWHF) is a traditional Chinese medicine widely used in the treatment of systemic lupus erythematosus (SLE), with triptolide (TP) as its main active ingredient. However, its side effects also induced by TP, especially hepatotoxicity and reproductive toxicity, largely limit its application in a subset of patients. Monoclonal antibodies (mAbs) developed for the treatment of SLE that deplete B cells by targeting B cell-expressing antigens, such as CD19, have failed in clinical trials, partly due to their poor efficacy in consuming B cells. Here, we report the development of a rationally designed antibody‒drug conjugate (ADC), CD19 mAb-TP conjugate, to alleviate the side effects of TWHF and simultaneously improve the therapeutic efficacy of CD19 mAb. The CD19 mAb-TP conjugate, which was named ADC-TP, selectively depleted B cell subsets both in vitro and in vivo and effectively alleviated disease symptoms in mouse lupus models with enhanced therapeutic efficacy than CD19 mAb and fewer side effects than TP. Our present study proposes a CD19 mAb‒TP conjugate strategy to mitigate the toxicity of TWHF while also enhancing the therapeutical efficacy of CD19 mAbs for the treatment of SLE, providing a feasible method for improving the current agents used for treating SLE.

De novo synthesis of monounsaturated fatty acids modulates exosome-mediated lipid export from human granulosa cells

BACKGROUND

Ovarian somatic cells support the maturation and fertility of oocytes. Metabolic desaturation of fatty acids in these cells has a positive paracrine impact on the maturation of oocytes. We hypothesized that the enzyme stearoyl-CoA desaturase 1 (SCD1) in granulosa cells regulates the lipid cargo of exosomes secreted from these cells by maintaining the balance between saturated and unsaturated lipids. We investigated the effect of SCD1 on exosome lipid content in a cumulus-granulosa cell model under physiologically relevant in vitro conditions.

METHODS

Non-luteinized human COV434 granulosa cells were subjected to treatment with an inhibitor of SCD1 (SCDinhib) alone, in combination with oleic acid, or under control conditions. Subsequently, the exosomes were isolated and characterized via nanoparticle tracking analysis, transmission electron microscopy, and Western blotting. We used liquid chromatography mass spectrometry to investigate the lipidomic profiles. We used quantitative PCR with TaqMan primers to assess the expression of genes involved in lipogenesis and control of cell cycle progression.

RESULTS

A trend toward exosome production was observed with a shift toward smaller exosome sizes in cells treated with SCD1inhib. This trend reached statistical significance when SCDinhib was combined with oleic acid supplementation. SCD1 inhibition led to the accumulation of saturated omega-6 lipids in exosomes. The latter effect was reversed by oleic acid supplementation, which also improved exosome production and suppressed the expression of fatty acid synthase and Cyclin D2.

CONCLUSION

These findings underscore the critical role of de novo fatty acid desaturation in the regulation of the export of specific lipids through exosomes, with potential implications for controlling intercellular communication within the ovary.

MODY Only Monogenic? A Narrative Review of the Novel Rare and Low-Penetrant Variants

Maturity-onset diabetes of the young (MODY) represents the most frequent form of monogenic diabetes mellitus (DM), currently classified in 14 distinct subtypes according to single gene mutations involved in the differentiation and function of pancreatic β-cells. A significant proportion of MODY has unknown etiology, suggesting that the genetic landscape is still to be explored. Recently, novel potentially MODY-causal genes, involved in the differentiation and function of β-cells, have been identified, such as RFX6, NKX2.2, NKX6.1, WFS1, PCBD1, MTOR, TBC1D4, CACNA1E, MNX1, AKT2, NEUROG3, EIF2AK3, GLIS3, HADH, and PTF1A. Genetic and clinical features of MODY variants remain highly heterogeneous, with no direct genotype-phenotype correlation, especially in the low-penetrant subtypes. This is a narrative review of the literature aimed at describing the current state-of-the-art of the novel likely MODY-associated variants. For a deeper understanding of MODY complexity, we also report some related controversies concerning the etiological role of some of the well-known pathological genes and MODY inheritance pattern, as well as the rare association of MODY with autoimmune diabetes. Due to the limited data available, the assessment of MODY-related genes pathogenicity remains challenging, especially in the setting of rare and low-penetrant subtypes. In consideration of the crucial importance of an accurate diagnosis, prognosis and management of MODY, more studies are warranted to further investigate its genetic landscape and the genotype-phenotype correlation, as well as the pathogenetic contribution of the nongenetic modifiers in this cohort of patients.

Interaction of ncRNAs and the PI3K/AKT/mTOR pathway: Implications for osteosarcoma

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents, and is characterized by high heterogeneity, high malignancy, easy metastasis, and poor prognosis. Recurrence, metastasis, and multidrug resistance are the main problems that limit the therapeutic effect and prognosis of OS. PI3K/AKT/mTOR signaling pathway is often abnormally activated in OS tissues and cells, which promotes the rapid development, metastasis, and drug sensitivity of OS. Emerging evidence has revealed new insights into tumorigenesis through the interaction between the PI3K/AKT/mTOR pathway and non-coding RNAs (ncRNAs). Therefore, we reviewed the interactions between the PI3K/AKT/mTOR pathway and ncRNAs and their implication in OS. These interactions have the potential to serve as cancer biomarkers and therapeutic targets in clinical applications.

PDCD4 as a marker of mTOR pathway activation and therapeutic target in mycobacterial infections

Programmed cell death protein 4 (PDCD4) is instrumental in regulating a range of cellular processes such as translation, apoptosis, signal transduction, and inflammatory responses. There is a notable inverse correlation between PDCD4 and the mammalian target of rapamycin (mTOR) pathway, which is integral to cellular growth control. Activation of mTOR is associated with the degradation of PDCD4. Although the role of PDCD4 is well established in oncogenesis and immune response regulation, its function in mycobacterial infections and its interplay with the mTOR pathway necessitate further elucidation. This study investigates the modulation of PDCD4 expression in the context of mycobacterial infections, revealing a consistent pattern of downregulation across diverse mycobacterial species. This observation underscores the potential utility of PDCD4 as a biomarker for assessing mTOR pathway activation during such infections. Building on this finding, we employed a novel approach using PDCD4-based mTOR (Tor)-signal-indicator (TOSI) reporter cells for the high-throughput screening of FDA-approved drugs, focusing on mTOR inhibitors. This methodology facilitated the identification of several agents, inclusive of known mTOR inhibitors, which upregulated PDCD4 expression and concurrently exhibited efficacy in impeding mycobacterial proliferation within macrophages. These results not only reinforce the significance of PDCD4 as a pivotal marker in the understanding of infectious diseases, particularly mycobacterial infections, but also illuminate its potential in the identification of mTOR inhibitors, thereby contributing to the advancement of therapeutic strategies.

IMPORTANCE

This study emphasizes the critical role of the mammalian target of rapamycin (mTOR) pathway in macrophage responses to mycobacterial infections, elucidating how mycobacteria activate mTOR, resulting in PDCD4 degradation. The utilization of the (Tor)-signal-indicator (TOSI) vector for real-time monitoring of mTOR activity represents a significant advancement in understanding mTOR regulation during mycobacterial infection. These findings deepen our comprehension of mycobacteria's innate immune mechanisms and introduce PDCD4 as a novel marker for mTOR activity in infectious diseases. Importantly, this research laid the groundwork for high-throughput screening of mTOR inhibitors using FDA-approved drugs, offering the potential for repurposing treatments against mycobacterial infections. The identification of drugs that inhibit mTOR activation opens new avenues for host-directed therapies, marking a significant step forward in combating tuberculosis and other mycobacterial diseases.

Transcriptome-based network analysis reveals hub immune genes and pathways of hepatopancreas against LPS in Amphioctopus fangsiao

The hepatopancreas is the biggest digestive organ in Amphioctopus fangsiao (A. fangsiao), but also undertakes critical functions like detoxification and immune defense. Generally, pathogenic bacteria or endotoxin from the gut microbiota would be arrested and detoxified in the hepatopancreas, which could be accompanied by the inevitable immune responses. In recent years, studies related to cephalopods immune have been increasing, but the molecular mechanisms associated with the hepatopancreatic immunity are still unclear. In this study, lipopolysaccharide (LPS), a major component of the cell wall of Gram-negative bacteria, was used for imitating bacteria infection to stimulate the hepatopancreas of A. fangsiao. To investigate the immune process happened in A. fangsiao hepatopancreas, we performed transcriptome analysis of hepatopancreas tissue after LPS injection, and identified 2615 and 1943 differentially expressed genes (DEGs) at 6 and 24 h post-injection, respectively. GO and KEGG enrichment analysis showed that these DEGs were mainly involved in immune-related biological processes and signaling pathways, including ECM-receptor interaction signaling pathway, Phagosome signaling pathway, Lysosome signaling pathway, and JAK-STAT signaling pathways. The function relationships between these DEGs were further analyzed through protein-protein interaction (PPI) networks. It was found that Mtor, Mapk14 and Atm were the three top interacting DEGs under LPS stimulation. Finally, 15 hub genes involving multiple KEGG signaling pathways and PPI relationships were selected for qRT-PCR validation. In this study, for the first time we explored the molecular mechanisms associated with hepatopancreatic immunity in A. fangsiao using a PPI networks approach, and provided new insights for understanding hepatopancreatic immunity in A. fangsiao.

Transgenerational hormesis in healthy aging and antiaging medicine from bench to clinics: Role of food components

Neurodegenerative diseases have multifactorial pathogenesis, mainly involving neuroinflammatory processes. Finding drugs able to treat these diseases, expecially because for most of these diseases there are no effective drugs, and the current drugs cause undesired side effects, represent a crucial point. Most in vivo and in vitro studies have been concentrated on various aspects related to neurons (e.g. neuroprotection), however, there has not been focus on the prevention of early stages involving glial cell activation and neuroinflammation. Recently, it has been demonstrated that nutritional phytochemicals including polyphenols, the main active constituents of the Mediterranean diet, maintain redox balance and neuroprotection through the activation of hormetic vitagene pathway. Recent lipidomics data from our laboratory indicate mushrooms as strong nutritional neuronutrients with strongly activity against neuroinflammation in Meniere' diseaseas, a model of cochleovestibular neural degeneration, as well as in animal model of traumatic brain injury, or rotenone induced parkinson's disease. Moreover, Hidrox®, an aqueous extract of olive containing hydroxytyrosol, and Boswellia, acting as Nrf2 activators, promote resilience by enhancing the redox potential, and thus, regulate through hormetic mechanisms, cellular stress response mechanisms., Thus, modulation of cellular stress pathways, in particular vitagenes system, may be an innovative approach for therapeutic intervention in neurodegenerative disorders.

Vistusertib improves pulmonary inflammation and fibrosis by modulating inflammatory/oxidative stress mediators via suppressing the mTOR signalling

INTRODUCTION

Inflammation and oxidative stress are key factors in the development of pulmonary fibrosis (PF) by promoting the differentiation of fibroblasts through modulating various pathways including Wnt/β-catenin, TGF-β and mTOR signalling.

OBJECTIVE AND METHODS

This study aimed to evaluate the effects and elucidate the mechanisms of vistusertib (VSB) in treating pulmonary inflammation/fibrosis, specifically by targeting the mTOR pathway using various in vitro and in vivo models.

RESULTS

Lipopolysaccharide (LPS)-induced inflammation model in macrophages (RAW 264.7), epithelial (BEAS-2B) and endothelial (HMVEC-L) cells revealed that treatment with VSB significantly reduced the IL-6, TNF-α, CCL2, and CCL7 expression. TGF-β induced differentiation was also significantly reduced upon VSB treatment in fibrotic cells (LL29 and DHLF). Further, bleomycin-induced inflammation and fibrosis models demonstrated that treatment with VSB significantly ameliorated the severe inflammation, and lung architectural distortion, by reducing the inflammatory markers expression/levels, inflammatory cells and oxidative stress indicators. Further, fibrosis model results exhibited that, VSB treatment significantly reduced the α-SMA, collagen and TGF-β expressions, improved the lung architecture and restored lung functions.

CONCLUSION

Overall, this study uncovers the anti-inflammatory/anti-fibrotic effects of VSB by modulating the mTOR activation. Although VSB was tested for lung fibrosis, it can be tested for other fibrotic disorders to improve the patient's survival and quality of life.

Dysregulation of autophagy in gastric carcinoma: Pathways to tumor progression and resistance to therapy

The considerable death rates and lack of symptoms in early stages of gastric cancer (GC) make it a major health problem worldwide. One of the most prominent risk factors is infection with Helicobacter pylori. Many biological processes, including those linked with cell death, are disrupted in GC. The cellular "self-digestion" mechanism necessary for regular balance maintenance, autophagy, is at the center of this disturbance. Misregulation of autophagy, however, plays a role in the development of GC. In this review, we will examine how autophagy interacts with other cell death processes, such as apoptosis and ferroptosis, and how it affects the progression of GC. In addition to wonderful its role in the epithelial-mesenchymal transition, it is engaged in GC metastasis. The role of autophagy in GC in promoting drug resistance stands out. There is growing interest in modulating autophagy for GC treatment, with research focusing on natural compounds, small-molecule inhibitors, and nanoparticles. These approaches could lead to breakthroughs in GC therapy, offering new hope in the fight against this challenging disease.

CCR5 and inflammatory storm

Chemokines and their corresponding receptors play crucial roles in orchestrating inflammatory and immune responses, particularly in the context of pathological conditions disrupting the internal environment. Among these receptors, CCR5 has garnered considerable attention due to its significant involvement in the inflammatory cascade, serving as a pivotal mediator of neuroinflammation and other inflammatory pathways associated with various diseases. However, a notable gap persists in comprehending the intricate mechanisms governing the interplay between CCR5 and its ligands across diverse and intricate inflammatory pathologies. Further exploration is warranted, especially concerning the inflammatory cascade instigated by immune cell infiltration and the precise binding sites within signaling pathways. This study aims to illuminate the regulatory axes modulating signaling pathways in inflammatory cells by providing a comprehensive overview of the pathogenic processes associated with CCR5 and its ligands across various disorders. The primary focus lies on investigating the pathomechanisms associated with CCR5 in disorders related to neuroinflammation, alongside the potential impact of aging on these processes and therapeutic interventions. The discourse culminates in addressing current challenges and envisaging potential future applications, advocating for innovative research endeavors to advance our comprehension of this realm.

Communication molecules (ncRNAs) mediate tumor-associated macrophage polarization and tumor progression

Non-coding RNAs play important roles in tumor cells and macrophages and participate in their communication as messengers. Non-coding RNAs have an impact in tumor cell proliferation, migration, and apoptosis, and they also regulate the differentiation and regulation of immune cells. In macrophages, they stimulate the polarization of macrophages into M1 or M2 by regulating proteins related to signaling pathways; in tumor cells, non-coding RNAs can enter macrophages through exosomes and affect the latter polarization. The polarization of macrophages further regulates the biological functions of cancer cells. The direction of macrophage polarization determines tumor progression, angiogenesis and drug resistance. This often creates a feedback loop. Non-coding RNAs act as bridges between tumor cells and macrophages to regulate the balance of the tumor microenvironment. We reviewed the signaling pathways related to macrophage polarization and the regulatory mechanisms of non-coding RNA in tumor-associated macrophages M1 and M2, and discussed the potential applications and prospects of exosome engineering.

Effects of apigenin on gastric cancer cells

Gastric Cancer (GC) is one of the most prevalent cancers worldwide. As the currently available therapeutic options are invasive, new and more benign options are being explored. One of which is Apigenin (Api), a natural flavonoid found in fruits and vegetables, such as celery, parsley, garlic, bell pepper and chamomile tea. Api has known anti-inflammatory, -oxidant, and -proliferative proprieties in several diseases and its potential as an anticancer compound has been explored. Here we systematize the available data regarding the effects of Api on GC cells, in terms of cell proliferation, apoptosis, Helicobacter pylori (H. pylori) infection, and molecular targets. From the literature it is possible to conclude that Api inhibits cell growth in a dose- and time-dependent manner, which is accompanied by the reduction of clone formation and induction of apoptosis. This occurs through the Akt/Bad/Bcl2/Bax axis that activates the mitochondrial pathway of apoptosis, resulting in restriction of cell proliferation. Additionally, it seems that the anti-proliferative potential of Api on GC cells is particularly relevant in a more aggressive GC phenotype but can also affect normal gastric cells. This indicate that this flavonoid must be used in low-to-moderate doses to avoid side-effects induced by disturbance of the normal epithelium. In H. Pylori-infected cells, the literature demonstrates that Api reduces inflammation by diminishing the levels of H. pylori colonization, by preventing NF-kB activation and by diminishing the production of reactive oxygen specimens (ROS). Accordingly, in GC Api seems to regulate different hallmarks of cancer, such as cell proliferation, apoptosis, cell migration, inflammation and oxidative stress, demonstrating its potential has an anti-GC compound.

Landscape of unconventional γδ T cell subsets in cancer

T cells are broadly categorized into two groups, namely conventional and unconventional T cells. Conventional T cells are the most prevalent and well-studied subset of T cells. On the other hand, unconventional T cells exhibit diverse functions shared between innate and adaptive immune cells. During recent decades, γδ T cells have received attention for their roles in cancer immunity. These cells can detect various molecules, such as lipids and metabolites. Also, they are known for their distinctive ability to recognize and target cancer cells in the tumor microenvironment (TME). This feature of γδ T cells could provide a unique therapeutic tool to fight against cancer. Understanding the role of γδ T cells in TME is essential to prepare the groundwork to use γδ T cells for clinical purposes. Here, we provide recent knowledge regarding the role γδ T cell subsets in different cancer types.

Highly-Efficient Gallium-Interference Tumor Therapy Mediated by Gallium-Enriched Prussian Blue Nanomedicine

Prussian blue (PB)-based nanomedicines constructed from metal ion coordination remain restricted due to their limited therapeutic properties, and their manifold evaluation complexity still needs to be unraveled. Owing to the high similarities of its ionic form to iron (Fe) and the resulting cellular homeostasis disruption performance, physiologically unstable and low-toxicity gallium (Ga) has garnered considerable attention clinically as an anti-carcinogen. Herein, Ga-based nanoparticles (NPs) with diverse Ga contents are fabricated in one step using PB with abundant Fe sites as a substrate for Ga substitution, which aims to overcome the deficiencies of both and develop an effective nanomedicine. A systematic comparison of their physicochemical properties effectively reveals the saturated Ga introduction state during the synthesis process, further identifying the most Ga-enriched PB NPs with a substitution content of >50% as a nanomedicine for subsequent exploration. It is verified that the Ga interference mechanisms mediated by the most Ga-enriched PB NPs are implicated in metabolic disorders, ionic homeostasis disruption, cellular structure dysfunction, apoptosis, autophagy, and target activation of the mammalian target of the rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) pathways. This study provides significant guidance on exploiting clinically approved agents for Ga interference and lays the foundation for the next generation of PB-based theranostic agents.

Unveiling Novel Avenues in mTOR-Targeted Therapeutics: Advancements in Glioblastoma Treatment

The mTOR signaling pathway plays a pivotal and intricate role in the pathogenesis of glioblastoma, driving tumorigenesis and proliferation. Mutations or deletions in the PTEN gene constitutively activate the mTOR pathway by expressing growth factors EGF and PDGF, which activate their respective receptor pathways (e.g., EGFR and PDGFR). The convergence of signaling pathways, such as the PI3K-AKT pathway, intensifies the effect of mTOR activity. The inhibition of mTOR has the potential to disrupt diverse oncogenic processes and improve patient outcomes. However, the complexity of the mTOR signaling, off-target effects, cytotoxicity, suboptimal pharmacokinetics, and drug resistance of the mTOR inhibitors pose ongoing challenges in effectively targeting glioblastoma. Identifying innovative treatment strategies to address these challenges is vital for advancing the field of glioblastoma therapeutics. This review discusses the potential targets of mTOR signaling and the strategies of target-specific mTOR inhibitor development, optimized drug delivery system, and the implementation of personalized treatment approaches to mitigate the complications of mTOR inhibitors. The exploration of precise mTOR-targeted therapies ultimately offers elevated therapeutic outcomes and the development of more effective strategies to combat the deadliest form of adult brain cancer and transform the landscape of glioblastoma therapy.