Quantitative Assessment of Preanalytic Variables on Clinical Evaluation of PI3/AKT/mTOR Signaling Activity in Diffuse Glioma.

Biomarker-driven therapeutic clinical trials require the implementation of standardized, evidence-based practices for sample collection. In diffuse glioma, phosphatidylinositol 3 (PI3)-kinase/AKT/mTOR (PI3/AKT/mTOR) signaling is an attractive therapeutic target for which window-of-opportunity clinical trials could facilitate the identification of promising new agents. Yet, the relevant preanalytic variables and optimal tumor sampling methods necessary to measure pathway activity are unknown. To address this, we used a murine model for isocitrate dehydrogenase (IDH)-wildtype glioblastoma (GBM) and human tumor tissue, including IDH-wildtype GBM and IDH-mutant diffuse glioma. First, we determined the impact of delayed time-to-formalin fixation, or cold ischemia time (CIT), on the quantitative assessment of cellular expression of 6 phosphoproteins that are readouts of PI3K/AK/mTOR activity (phosphorylated-proline-rich Akt substrate of 40 kDa (p-PRAS40, T246), -mechanistic target of rapamycin (p-mTOR; S2448); -AKT (p-AKT, S473); -ribosomal protein S6 (p-RPS6, S240/244 and S235/236), and -eukaryotic initiation factor 4E-binding protein 1 (p-4EBP1, T37/46). With CITs ≥ 2 hours, typical of routine clinical handling, all had reduced or altered expression with p-RPS6 (S240/244) exhibiting relatively greater stability. A similar pattern was observed using patient tumor samples from the operating room with p-4EBP1 more sensitive to delayed fixation than p-RPS6 (S240/244). Many clinical trials utilize unstained slides for biomarker evaluation. Thus, we evaluated the impact of slide storage conditions on the detection of p-RPS6 (S240/244), p-4EBP1, and p-AKT. After 5 months, storage at -80°C was required to preserve the expression of p-4EBP1 and p-AKT, whereas p-RPS6 (240/244) expression was not stable regardless of storage temperature. Biomarker heterogeneity impacts optimal tumor sampling. Quantification of p-RPS6 (240/244) expression in multiple regionally distinct human tumor samples from 8 patients revealed significant intratumoral heterogeneity. Thus, the accurate assessment of PI3K/AKT/mTOR signaling in diffuse glioma must overcome intratumoral heterogeneity and multiple preanalytic factors, including time-to-formalin fixation, slide storage conditions, and phosphoprotein of interest.

The highly selective and oral phosphoinositide 3-kinase delta (PI3K-δ) inhibitor roginolisib induces apoptosis in mesothelioma cells and increases immune effector cell composition.

Targeting aberrantly expressed kinases in malignant pleural mesothelioma (MPM) is a promising therapeutic strategy. We here investigated the effect of the novel and highly selective Phosphoinositide 3-kinase delta (PI3K-δ) inhibitor roginolisib (IOA-244) on MPM cells and on the immune cells in MPM microenvironment. To this aim, we analyzed the expression of PI3K-δ by immunohistochemistry in specimens from primary MPM, cell viability and death in three different MPM cell lines treated with roginolisib alone and in combination with ipatasertib (AKT inhibitor) and sapanisertib (mTOR inhibitor). In a co-culture model of patient-derived MPM cells, autologous peripheral blood mononuclear cells and fibroblasts, the tumor cell viability and changes in immune cell composition were investigated after treatment of roginolisib with nivolumab and cisplatin. PI3K-δ was detected in 66/89 (74%) MPM tumors and was associated with reduced overall survival (12 vs. 25 months, P=0.0452). Roginolisib induced apoptosis in MPM cells and enhanced the anti-tumor efficacy of AKT and mTOR kinase inhibitors by suppressing PI3K-δ/AKT/mTOR and ERK1/2 signaling. Furthermore, the combination of roginolisib with chemotherapy and immunotherapy re-balanced the immune cell composition, increasing effector T-cells and reducing immune suppressive cells. Overall, roginolisib induces apoptosis in MPM cells and increases the antitumor immune cell effector function when combined with nivolumab and cisplatin. These results provide first insights on the potential of roginolisib as a therapeutic agent in patients with MPM and its potential in combination with established immunotherapy regimen.

Therapeutic potential of sulforaphane: modulation of NRF2 mediated PI3/AKT/mTOR pathway in oral fibrosis / Potencial terapêutico do sulforafano: modulação do NRF-2 mediado o pela via PI3/AKT/mTOR na fibrose oral

Oral Submucous Fibrosis is a potentially malignant disorder caused by habitual areca nut chewing, which contributes to the dispersion of active alkaloids into subepithelial tissues, stimulating excessive extracellular matrix deposition. Various treatment modalities are available; however, their efficacy in inhibiting fibrosis progression remains limited. Sulforaphane (SFN), an isothiocyanate found abundantly in cruciferous plants, is known to have effective antifibrotic properties. Objective: The present study investigated the antifibrotic effect of SFN via phosphatidylinositol 3 kinase (PI3K), Serine/Threonine Kinase 1 (AKT-1), mammalian target of rapamycin (mTOR) pathway in arecoline (AER) induced fibrosis in human gingival fibroblasts [HGFs]. Material and Methods: MTT assay determined the half-maximal inhibitory concentration of AER and SFN at 24h in the HGF cell line. Expression levels of transforming growth factor ß1 (TGFß1), collagen type 1 alpha 2 (COL1A2), hydroxyproline (HYP), PI3, AKT, mTOR, and nuclear factor erythroid 2­related factor 2 (NRF2) were assessed post-AER and SFN treatment using qPCR and western blot analysis. Results: The findings of the study revealed that AER elicited a stimulatory effect, upregulating TGFß1, COL1A2, HYP, PI3K, AKT, and mTOR and downregulating NRF2 expression. Conversely, SFN treatment significantly upregulated NRF2, inhibiting TGFß1 mediated PI3/AKT/mTOR pathway. Conclusion: These observations suggest that SFN can be used as a promising synergistic antifibrotic agent to combat fibrogenesis via the non-Smad pathway (AU)

Fibrose submucosa oral é uma desordem potencialmente maligna causada pelo habito de mascar a noz da areca, o que contribui para a dispersão de alcalóides ativos nos tecidos subepiteliais, estimulando a deposição excessiva de matriz extracelular. Há várias modalidades terapêuticas, no entanto, com eficácia limitada no controle da progressão da fibrose. O sulforafano (SFN), isotiocianato encontrado abundantemente em plantas crucíferas, é conhecido por suas propriedades antifibróticas. Objetivo: Investigar os efeitos antifibróticos do SFN na via fosfatidilinositol3-quinase (PI3K), via quinase serina/treonina 1 (AKT-1), via do alvo da rapamicina em mamíferos (mTOR), na fibrose induzida por arecolina (AER) em fibroblastos gengivais de humanos (HGFs). Material e Métodos: A meia concentração inibitória mínima de AER e SFN em 24 horas nas células HGFs foi determinada por MTT. Os níveis de expressão de ß1 (TGFß1), colágeno tipo 1 alfa 2 (COL1A2), hidroxiprolina (HYP), PI3K, AKT, mTOR, fator nuclear eritroide 2 relacionado ao fator 2 (NRF2) foram analisados após tratamento com ERA e SFN através de qPCR e western blot. Resultados: O ERA apresentou efeito estimulatório aumentando a expressão de TGFß1, COL1A2, HYP, PI3K, AKT e mTOR e diminuindo a expressão de NRF2. Por outro lado, tratamento com SFN aumentou significativamente a expressão de NRF2, inibindo a liberação de TGFß1 mediada pela via PI3/AKT/mTOR. Conclusão: Esses achados sugerem que o SFN pode ser um agente antifibrótico promissor no combate à fibrogênese decorrente da via não-Smad (AU)

Impairment of insulin signaling pathway PI3K/Akt/mTOR and insulin resistance induced AGEs on diabetes mellitus and neurodegenerative diseases: a perspective review.

Insulin resistance is common in type 2 diabetes mellitus (T2DM), neurodegenerative diseases, cardiovascular diseases, kidney diseases, and polycystic ovary syndrome. Impairment in insulin signaling pathways, such as the PI3K/Akt/mTOR pathway, would lead to insulin resistance. It might induce the synthesis and deposition of advanced glycation end products (AGEs), reactive oxygen species, and reactive nitrogen species, resulting in stress, protein misfolding, protein accumulation, mitochondrial dysfunction, reticulum function, and metabolic syndrome dysregulation, inflammation, and apoptosis. It plays a huge role in various neurodegenerative diseases like Parkinson's disease, Alzheimer's disease, Huntington's disease, and Amyloid lateral sclerosis. In this review, we intend to focus on the possible effect of insulin resistance in the progression of neurodegeneration via the impaired P13K/Akt/mTOR signaling pathway, AGEs, and receptors for AGEs.

G Protein-Coupled Receptor 37L1 Modulates Epigenetic Changes in Human Renal Proximal Tubule Cells.

Renal luminal sodium transport is essential for physiological blood pressure control, and abnormalities in this process are strongly implicated in the pathogenesis of essential hypertension. Renal G protein-coupled receptors (GPCRs) are critical for the regulation of the reabsorption of essential nutrients, ions, and water from the glomerular filtrate. Recently, we showed that GPCR 37L1 (GPR37L1) is expressed on the apical membrane of renal proximal tubules (RPT) and regulates luminal sodium transport and blood pressure by modulating the function of the sodium proton exchanger 3 (NHE3). However, little is known about GPR37L1 intracellular signaling. Here, we show that GPR37L1 is localized to the nuclear membrane, in addition to the plasma membrane in human RPT cells. Furthermore, GPR37L1 signals via the PI3K/AKT/mTOR pathway to decrease the expression of DNA (cytosine-5)-methyltransferase 1 (DNMT1) and enhance NHE3 transcription. Overall, we demonstrate the direct role of a nuclear membrane GPCR in the regulation of renal sodium through epigenetic gene regulation.

High concentration of sodium fluoride in drinking water induce hypertrophy versus atrophy in mouse skeletal muscle via modulation of sarcomeric proteins.

Fluoride at high doses is a well-known toxic agent for the musculoskeletal system, primarily in bone and cartilage cells. Research on fluoride toxicity concerning particularly on the skeletal muscle is scanty. We hypothesized that during skeletal fluorosis, along with bone, muscle is also affected, so we have evaluated the effects of Sodium fluoride (NaF) on mouse skeletal muscles. Sodium fluoride (80 ppm) was administered to 5-week-old C57BL6 mice drinking water for 15 and 60 days, respectively. We carried out histology, primary culture, molecular and proteomic analysis of fluoride administered mouse skeletal muscles. Results indicated an increase in the muscle mass (hypertrophy) in vivo and myotubes ex vivo by activating the IGF1/PI3/Akt/mTOR signalling pathway due to short term NaF exposure. The long-term exposure of mice to NaF caused loss of muscle proteins leading to muscle atrophy due to activation of the ubiquitin-proteasome pathway. Differentially expressed proteins were characterized and mapped using a proteomic approach. Moreover, the factors responsible for protein synthesis and PI3/Akt/mTOR pathway were upregulated, leading to muscle hypertrophy during the short term NaF exposure. Long term exposure to NaF resulted in down-regulation of metabolic pathways. Elevated myostatin resulted in the up-regulation of the muscle-specific E3 ligases-MuRF1, promoting the ubiquitination and proteasome-mediated degradation of critical sarcomeric proteins.

Anticancer Activity of Diosgenin and Its Semi-synthetic Derivatives: Role in Autophagy Mediated Cell Death and Induction of Apoptosis.

During cancer progression, the unrestricted proliferation of cells is supported by the impaired cell death response provoked by certain oncogenes. Both autophagy and apoptosis are the signaling pathways of cell death, which are targeted for cancer treatment. Defects in apoptosis result in reduced cell death and ultimately tumor progression. The tumor cells lacking apoptosis phenomena are killed by ROS- mediated autophagy. The autophagic programmed cell death requires apoptosis protein for inhibiting tumor growth; thus, the interconnection between these two pathways determines the fate of a cell. The cross-regulation of autophagy and apoptosis is an important aspect to modulate autophagy, apoptosis and to sensibilise apoptosis-resistant tumor cells under metabolic stress and might be a rational approach for drug designing strategy for the treatment of cancer. Numerous proteins involved in autophagy have been investigated as the druggable target for anticancer therapy. Several compounds of natural origin have been reported, to control autophagy activity through the PI3K/Akt/mTOR key pathway. Diosgenin, a steroidal sapogenin has emerged as a potential candidate for cancer treatment. It induces ROS-mediated autophagy, inhibits PI3K/Akt/mTOR pathway, and produces cytotoxicity selectively in cancer cells. This review aims to focus on optimal strategies using diosgenin to induce apoptosis by modulating the pathways involved in autophagy regulation and its potential implication in the treatment of various cancer. The discussion has been extended to the medicinal chemistry of semi-synthetic derivatives of diosgenin exhibiting anticancer activity.

Extracellular Vesicle Activation of Latent HIV-1 Is Driven by EV-Associated c-Src and Cellular SRC-1 via the PI3K/AKT/mTOR Pathway.

HIV-1 is a global health crisis that has infected more than 37 million people. Latent reservoirs throughout the body are a major hurdle when it comes to eradicating the virus. In our previous study, we found that exosomes, a type of extracellular vesicle (EV), from uninfected cells activate the transcription of HIV-1 in latent infected cells, regardless of combination antiretroviral therapy (cART). In this study, we investigated the specific mechanism behind the EV activation of latent HIV-1. We found that phosphorylated c-Src is present in EVs of various cell lines and has the ability to activate downstream proteins such as EGFR, initiating a signal cascade. EGFR is then able to activate the PI3K/AKT/mTOR pathway, resulting in the activation of STAT3 and SRC-1, culminating in the reversal of HIV-1 latency. This was verified by examining levels of HIV-1 TAR, genomic RNA and HIV-1 Gag p24 protein in cell lines and primary cells. We found that EVs containing c-Src rescued HIV-1 despite the presence of inhibitors, validating the importance of EV-associated c-Src in latent HIV-1 activation. Lastly, we discovered an increased recruitment of p300 and NF-κB in the nucleus of EV-treated infected cells. Collectively, our data suggest that EV-associated c-Src is able to activate latent HIV-1 via the PI3K/AKT/mTOR pathway and SRC-1/p300-driven chromatin remodeling. These findings could aid in designing new strategies to prevent the reactivation of latent HIV-1 in patients under cART.

Emerging drugs for the treatment of myelofibrosis.

INTRODUCTION: Myelofibrosis (MF) is a myeloproliferative neoplasm associated with significant disease burden composed of splenomegaly, constitutional symptoms and a reduced life expectancy. The advent of targeted treatments has provided new means by which to improve MF associated splenomegaly, symptoms, health-related quality of life and even mortality. AREAS COVERED: We discuss the spectrum of targeted treatments currently under investigation for MF. We furthermore compare their effects on improving anemia, reducing fibrosis and splenomegaly and enhancing symptom control. EXPERT OPINION: MF is a complex disorder, partly attributable to its heterogeneity. Although the severity of patient symptoms correlates with risk category, high symptom burden may also be observed in low-risk patients. Serial use of PRO tools allows clinicians to objectively evaluate the MF symptom burden, compare efficacy of therapies and adjust medications to improve symptom control. Novel targeted agents have proven superior to historic treatment regimens for symptom management. Promising treatment categories include JAK2 inhibitors, histone deacetylase inhibitors, hypomethylating agents, heat shock protein-90 inhibitors, hedgehog inhibitors, PI3-AKT-mTOR inhibitors, antifibrosing agents and telomerase inhibitors. The majority of therapies remain under investigation, either alone or in combination with other treatments. It is anticipated that these agents will be increasingly integrated into standard treatment algorithms for MF symptom management.

Multiple functional therapeutic effects of the estrogen receptor ß agonist indazole-Cl in a mouse model of multiple sclerosis.

Currently available immunomodulatory therapies do not stop the pathogenesis underlying multiple sclerosis (MS) and are only partially effective in preventing the onset of permanent disability in patients with MS. Identifying a drug that stimulates endogenous remyelination and/or minimizes axonal degeneration would reduce the rate and degree of disease progression. Here, the effects of the highly selective estrogen receptor (ER) ß agonist indazole chloride (Ind-Cl) on functional remyelination in chronic experimental autoimmune encephalomyelitis (EAE) mice were investigated by assessing pathologic, functional, and behavioral consequences of both prophylactic and therapeutic (peak EAE) treatment with Ind-Cl. Peripheral cytokines from autoantigen-stimulated splenocytes were measured, and central nervous system infiltration by immune cells, axon health, and myelination were assessed by immunohistochemistry and electron microscopy. Therapeutic Ind-Cl improved clinical disease and rotorod performance and also decreased peripheral Th1 cytokines and reactive astrocytes, activated microglia, and T cells in brains of EAE mice. Increased callosal myelination and mature oligodendrocytes correlated with improved callosal conduction and refractoriness. Therapeutic Ind-Cl-induced remyelination was independent of its effects on the immune system, as Ind-Cl increased remyelination within the cuprizone diet-induced demyelinating model. We conclude that Ind-Cl is a refined pharmacologic agent capable of stimulating functionally relevant endogenous myelination, with important implications for progressive MS treatment.