Phosphoinositide 3-kinase Signaling Research Articles

The Importance of Phosphoinositide 3-Kinase in Neuroinflammation.

Neuroinflammation, characterised by the activation of immune cells in the central nervous system (CNS), plays a dual role in both protecting against and contributing to the progression of neurodegenerative diseases, such as Alzheimer's disease (AD) and multiple sclerosis (MS). This review explores the role of phosphoinositide 3-kinase (PI3K), a key enzyme involved in cellular survival, proliferation, and inflammatory responses, within the context of neuroinflammation. Two PI3K isoforms of interest, PI3Kγ and PI3Kδ, are specific to the regulation of CNS cells, such as microglia, astrocytes, neurons, and oligodendrocytes, influencing pathways, such as Akt, mTOR, and NF-κB, that control cytokine production, immune cell activation, and neuroprotection. The dysregulation of PI3K signalling is implicated in chronic neuroinflammation, contributing to the exacerbation of neurodegenerative diseases. Preclinical studies show promise in targeting neuronal disorders using PI3K inhibitors, such as AS605240 (PI3Kγ) and idelalisib (PI3Kδ), which have reduced inflammation, microglial activation, and neuronal death in in vivo models of AD. However, the clinical translation of these inhibitors faces challenges, including blood-brain barrier (BBB) permeability, isoform specificity, and long-term safety concerns. This review highlights the therapeutic potential of PI3K modulation in neuroinflammatory diseases, identifying key gaps in the current research, particularly in the need for brain-penetrating and isoform-specific inhibitors. These findings underscore the importance of future research to develop targeted therapies that can effectively modulate PI3K activity and provide neuroprotection in chronic neurodegenerative disorders.

The role of PI3K signaling pathway in Alzheimer's disease.

Alzheimer's disease (AD) is a debilitating progressively neurodegenerative disease. The best-characterized hallmark of AD, which is marked by behavioral alterations and cognitive deficits, is the aggregation of deposition of amyloid-beta (Aβ) and hyper-phosphorylated microtubule-associated protein Tau. Despite decades of experimental progress, the control rate of AD remains poor, and more precise deciphering is needed for potential therapeutic targets and signaling pathways involved. In recent years, phosphoinositide 3-kinase (PI3K) and Akt have been recognized for their role in the neuroprotective effect of various agents, and glycogen synthase kinase 3 (GSK3), a downstream enzyme, is also crucial in the tau phosphorylation and Aβ deposition. An overview of the function of PI3K/Akt pathway in the pathophysiology of AD is provided in this review, along with a discussion of recent developments in the pharmaceuticals and herbal remedies that target the PI3K/Akt signaling pathway. In conclusion, despite the challenges and hurdles, cumulative findings of novel targets and agents in the PI3K/Akt signaling axis are expected to hold promise for advancing AD prevention and treatment.

Intracerebroventricular insulin injection acutely normalizes the augmented exercise pressor reflex in male rats with type 2 diabetes mellitus.

The exercise pressor reflex (EPR) is exaggerated in type 2 diabetes mellitus (T2DM), but the underlying central nervous system aberrations have not been fully delineated. Stimulation of muscle afferents within working skeletal muscle activates the EPR, by sending information to neurons in the brainstem, where it is integrated and results in reflexively increased mean arterial pressure (MAP) and sympathetic nerve activity. Brain insulin is known to regulate neural activity within the brainstem. We hypothesize that brain insulin injection in T2DM rats attenuates the augmented EPR, and that T2DM is associated with decreased brain insulin. Using male Sprague-Dawley rats, T2DM and control rats were generated via an induction protocol with two low doses of streptozotocin (35 and 25mg/kg, i.p.) in combination with a 14-23-week high-fat diet or saline injections and a low-fat diet, respectively. After decerebration, MAP and renal sympathetic nerve activity (RSNA) were evaluated during EPR stimulation, evoked by electrically induced muscle contraction via ventral root stimulation, before and after (1 and 2h post) intracerebroventricular (i.c.v.) insulin microinjections (500mU, 50nl). i.c.v. insulin decreased peak MAP (ΔMAP Pre (36±14mmHg) vs. 1h (21±14mmHg) vs. 2h (11±6mmHg), P<0.05) and RSNA (ΔRSNA Pre (107.5±40%), vs. 1h (75.4±46%) vs. 2h (51±35%), P<0.05) responses in T2DM, but not controls. In T2DM rats, cerebrospinal fluid insulin was decreased (0.41±0.19 vs. 0.11±0.05ng/ml, control (n=14) vs. T2DM (n=4), P<0.01). The results demonstrated that insulin injections into the brain normalized the augmented EPR in brain hypoinsulinaemic T2DM rats, indicating that the EPR can be regulated by brain insulin. KEY POINTS: The reflexive increase in blood pressure and sympathetic nerve activity mediated by the autonomic nervous system during muscle contractions is also known as the exercise pressor reflex. The exercise pressor reflex is dangerously augmented in type 2 diabetes, in both rats and humans. In type 2 diabetic rats both cerebrospinal fluid insulin and phosphoinositide 3-kinase signalling within cardiovascular brainstem neurons decrease in parallel. Brain insulin injections decrease the magnitude of the reflexive pressor and sympathetic responses to hindlimb muscle contraction in type 2 diabetic rats. Partial correction of low insulin within the central nervous system in type 2 diabetes may treat aberrant exercise pressor reflex function.

PI3K couples long-term synaptic potentiation with cofilin recruitment and actin polymerization in dendritic spines via its regulatory subunit p85α

Long-term synaptic plasticity is typically associated with morphological changes in synaptic connections. However, the molecular mechanisms coupling functional and structural aspects of synaptic plasticity are still poorly defined. The catalytic activity of type I phosphoinositide-3-kinase (PI3K) is required for specific forms of synaptic plasticity, such as NMDA receptor-dependent long-term potentiation (LTP) and mGluR-dependent long-term depression (LTD). On the other hand, PI3K signaling has been linked to neuronal growth and synapse formation. Consequently, PI3Ks are promising candidates to coordinate changes in synaptic strength with structural remodeling of synapses. To investigate this issue, we targeted individual regulatory subunits of type I PI3Ks in hippocampal neurons and employed a combination of electrophysiological, biochemical and imaging techniques to assess their role in synaptic plasticity. We found that a particular regulatory isoform, p85α, is selectively required for LTP. This specificity is based on its BH domain, which engages the small GTPases Rac1 and Cdc42, critical regulators of the actin cytoskeleton. Moreover, cofilin, a key regulator of actin dynamics that accumulates in dendritic spines after LTP induction, failed to do so in the absence of p85α or when its BH domain was overexpressed as a dominant negative construct. Finally, in agreement with this convergence on actin regulatory mechanisms, the presence of p85α in the PI3K complex determined the extent of actin polymerization in dendritic spines during LTP. Therefore, this study reveals a molecular mechanism linking structural and functional synaptic plasticity through the coordinate action of PI3K catalytic activity and a specific isoform of the regulatory subunits.

Chemical analogue based drug design for cancer treatment targeting PI3K: integrating machine learning and molecular modeling.

Cancer is a generic term for a group of disorders defined by uncontrolled cell growth and the potential to invade or spread to other parts of the body. Gene and epigenetic alterations disrupt normal cellular control, leading to abnormal cell proliferation, resistance to cell death, blood vessel development, and metastasis (spread to other organs). One of the several routes that play an important role in the development and progression of cancer is the phosphoinositide 3-kinase (PI3K) signaling pathway. Moreover, the gene PIK3CG encodes the catalytic subunit gamma (p110γ) of phosphoinositide 3-kinase (PI3Kγ), a member of the PI3K family. Therefore, in this study, PIK3CG was targeted to inhibit cancer by identifying a novel inhibitor through computational methods. The study screened 1015 chemical fragments against PIK3CG using machine learning-based binding estimation and docking to select the potential compounds. Later, the analogues were generated from the selected hits, and 414 analogues were selected, which were further screened, and as most potential candidates, three compounds were obtained: (a) 84,332, 190,213, and 885,387. The protein-ligand complex's stability and flexibility were then investigated by dynamic modeling. The 100ns simulation revealed that 885,387 exhibited the steadiest deviation and constant creation of hydrogen bonds. Compared to the other compounds, 885,387 demonstrated a superior binding free energy (ΔG = -18.80kcal/mol) with the protein when the MM/GBSA technique was used. The study determined that 885,387 showed significant therapeutic potential and justifies further experimental investigation as a possible inhibitor of the PIK3CG target implicated in cancer.

The therapeutic effect of Yinqiaosan decoction against influenza A virus infection by regulating T cell receptor signaling pathway

BackgroundYinqiaosan decoction (YQSD), a traditional Chinese medicinal recipe, has been employed to treat influenza in China for approximately 300 years. ObjectiveOur study aimed to explore the mechanisms of YQSD against influenza via in vivo and in vitro experimental studies. Study designand methods UHPLC-Q-TOF-MS/MS was utilized to examine the substances of the YQSD. The chemical components of YQSD detected by UHPLC-Q-TOF-MS/MS were used for network pharmacology analysis. The antiviral effect of YQSD in vivo was investigated. The potential mechanisms of YQSD in combating influenza, which were predicted from network pharmacology analysis, were validated in vitro. ResultsBy use of UHPLC-Q-TOF-MS/MS, 97 compounds were identified from YQSD. Network pharmacology analysis revealed that the therapeutic effect of YQSD against influenza may be associated with the regulation of T cell receptors (TCR) and Phosphoinositide 3-Kinase (PI3K)- protein kinase B (Akt) signaling pathways. Treatment with YQSD significantly prolonged the mean survival time of the mice and reduced lung injury due to the influenza A virus in vivo. It was discovered that YQSD efficiently inhibited the expression of inflammation-related cytokines. Moreover, YQSD has been found to significantly reduce the expression levels of cluster of differentiation 3 (CD3), monocyte chemoattractant protein-1 (MCP-1), and H1N1 virus nucleoprotein (NP), and prevent the decrease of epithelial cadherin (E-cadherin) protein. In addition, YQSD can inhibit the phosphorylation of the zeta chain of T cell receptor-associated protein kinase 70 (ZAP70) and PI3K proteins in vitro. ConclusionThe capacity of YQSD to suppress viral multiplication and inflammatory response by modulating T cell immunity may explain its effect against influenza viral pneumonia, which may involve the regulation of TCR and PI3K signaling pathways.

Construction of a 5-Gene super-enhancer-related signature for osteosarcoma prognosis and the regulatory role of TNFRSF11B in osteosarcoma

Osteosarcoma, one of the most common primary malignancies in children and adolescents, has the primary characteristics of a poor prognosis and high rate of metastasis. This study used super-enhancer-related genes derived from two different cell lines to construct five novel super-enhancer-related gene prognostic models for patients with osteosarcoma. The training and testing datasets were used to confirm the prognostic models of the five super-enhancer-related genes, which resulted in an impartial predictive element for osteosarcoma. The immunotherapy and prediction of the response to anticancer drugs have shown that the risk signature of the five super-enhancer-related genes positively correlate with chemosensitivity. Furthermore, functional analysis of the risk signature genes revealed a significant relationship between gene groups and the malignant characteristics of tumours. TNF Receptor Superfamily Member 11b (TNFRSF11B) was selected for functional verification. Silencing of TNFRSF11B suppressed the proliferation, migration, and invasion of osteosarcoma cells in vitro and suppressed osteosarcoma growth in vivo. Moreover, transcriptome sequencing was performed on MG-63 cells to study the regulatory mechanism of TNFRSF11B in osteosarcoma cells, and it was discovered that TNFRSF11B is involved in the development of osteosarcoma via the phosphoinositide 3-kinase signalling pathway. Following the identification of TNFRSF11B as a key gene, we selected an inhibitor that specifically targeted this gene and performed molecular docking simulations. In addition, risedronic acid inhibited osteosarcoma growth at both cellular and molecular levels. In conclusion, the super-enhancer-related gene signature is a viable therapeutic tool for osteosarcoma prognosis and treatment.

Neural progenitor-derived Apelin controls tip cell behavior and vascular patterning.

During angiogenesis, vascular tip cells guide nascent vascular sprouts to form a vascular network. Apelin, an agonist of the G protein-coupled receptor Aplnr, is enriched in vascular tip cells, and it is hypothesized that vascular-derived Apelin regulates sprouting angiogenesis. We identify an apelin-expressing neural progenitor cell population in the dorsal neural tube. Vascular tip cells exhibit directed elongation and migration toward and along the apelin-expressing neural progenitor cells. Notably, restoration of neural but not vascular apelin expression in apelin mutants remedies the angiogenic defects of mutants. By functional analyses, we show the requirement of Apelin signaling for tip cell behaviors, like filopodia formation and cell elongation. Through genetic interaction studies and analysis of transgenic activity reporters, we identify Apelin signaling as a modulator of phosphoinositide 3-kinase and extracellular signal-regulated kinase signaling in tip cells in vivo. Our results suggest a previously unidentified neurovascular cross-talk mediated by Apelin signaling that is important for tip cell function during sprouting angiogenesis.

Direct activation of PI3K in osteoblasts and osteocytes strengthens murine bone through sex-specific actions on cortical surfaces.

Intracellular phosphoinositide 3-kinase (PI3K) signaling is activated by multiple bone-active receptors. Genetic mutations activating PI3K signaling are associated with clinical syndromes of tissue overgrowth in multiple organs, often including the skeleton. While one formation is increased by removing the PI3K inhibitor (phosphatase and TENsin homolog deleted on chromosome 10 (PTEN)), the effect of direct PI3K activation in the osteoblast lineage has not been reported. We introduced a known gain-of-function mutation in Pik3ca, the gene encoding the p110α catalytic subunit of PI3K, in osteocytes and late osteoblasts using the dentin matrix protein-1 Cre (Dmp1Cre) mouse and assessed the skeletal phenotype. Femur shape was grossly normal, but cortical thickness was significantly greater in both male and female Dmp1Cre.Pik3caH1047R mice, leading to almost doubled bone strength at 12wk of age. Both sexes had smaller marrow areas from 6wk of age. Female mice also exhibited greater cross-sectional area, which continued to increase until 24wk of age, resulting in a further increase in bone strength. Although both male and female mice had increased endocortical mineralizing surface, only female mice had increased periosteal mineralizing surface. The bone formed in the Dmp1Cre.Pik3caH1047R mice showed no increase in intracortical remodeling nor any defect in cortical bone consolidation. In contrast, on both endocortical and periosteal surfaces, there was more lamellar bone formation, including highly organized osteocyte networks extending along the entire surface at a greater thickness than in control mice. In conclusion, direct activation of PI3Kα in cells targeted by Dmp1Cre leads to high cortical bone mass and strength with abundant lamellar cortical bone in female and male mice with no increase in intracortical remodeling. This differs from the effect of PTEN deletion in the same cells, suggesting that activating PI3Kα in osteoblasts and osteocytes may be a more suitable target to promote formation of lamellar bone.

Coffee, Phosphoinositide 3-Kinase Signaling Pathway, and Prostate Cancer: A Prospective Study in the Health Professionals Follow-Up Study

BackgroundHigher coffee intake has been associated with reduced risk of prostate cancer, particularly aggressive forms. The activation of the phosphoinositide 3-kinase (PI3K) signaling pathway plays an important role in prostate carcinogenesis. ObjectiveTo evaluate associations between prediagnostic coffee intake and a PI3K activation score, the expression/presence of PI3K regulators, and downstream effectors in tumor tissue from men with prostate cancer in the Health Professionals Follow-Up Study, a prospective cohort study conducted in the United States. DesignA case-only study design was applied. Coffee intake was assessed using validated food frequency questionnaires completed in 1986 and every 4 years thereafter until prostate cancer diagnosis. Participants settingStudy participants comprised 1242 men diagnosed with prostate cancer from 1986 to 2009 and with tumor markers assessed from tissue microarrays constructed from tumor specimens. Main outcome measuresThe outcomes include the PI3K activation score; expression of insulin receptor and insulin-like growth factor 1 receptor; angiogenesis markers; and presence of the tumor suppressor phosphatase and tensin homolog, chronic and acute inflammation, simple atrophy, and post-atrophic hyperplasia. Statistical analyses performedMultivariable linear or logistic regression was conducted to estimate associations between coffee intake and tumor marker expression/presence. ResultsAmong coffee drinkers (86.6% of the population), median (25th, 75th percentile) coffee intake was 2 c/day (1, 3 c/day). The associations between coffee consumption and the tumor markers of interest were generally weak with modest precision. When comparing men who drank >3 c/day coffee with nondrinkers, the absolute percent difference in the PI3K activation score and angiogenesis markers ranged from 0.6% to 3.6%. The odds ratios for phosphatase and tensin homolog loss, insulin-like growth factor 1 receptor and insulin receptor expression, and presence of chronic and acute inflammation, simple atrophy, and postatrophic hyperplasia also were not statistically significant, were imprecise, and ranged from 0.82 to 1.58. ConclusionsCoffee intake was not observed to be associated with PI3K activation, related regulators, and several effectors in prostate tumor tissue. Studies exploring alternative pathways or earlier steps in carcinogenesis are needed to investigate the underlying mechanisms of the coffee and prostate cancer association.

PKC-α is involved in the signaling of phagocytosis induced by two snake venom secretory PLA2S in macrophages

Phagocytosis, an essential process for host defense, requires the coordination of a variety of signaling reactions. MT-II, an enzymatically inactive Lys49 phospholipase A2 (PLA2) homolog, and MT-III, a catalytically-active Asp49 PLA2, are known to activate phagocytosis in macrophages. In this study, the signaling pathways mediating phagocytosis, focusing on protein kinases, were investigated. Macrophages from male Swiss mice peritoneum were obtained 96 h after intraperitoneal thioglycolate injection. Phagocytosis was evaluated using non-opsonized zymosan particles in the presence or absence of specific inhibitors, as well as PKC and PKC-α localization by confocal microscopy. Moreover, protein kinase C (PKC) activity was assessed by γP32 ATP in macrophages stimulated by both PLA2s. Data showed that both sPLA2s increased phagocytosis. Cytochalasin D, staurosporine/H7, wortmannin, and herbimycin, inhibitors of actin polymerization, PKC, phosphoinositide 3-kinase (PI3K), and protein tyrosine kinase (PTK), respectively, significantly reduced phagocytosis induced by both PLA2s. PKC activity was increased in macrophages stimulated by both PLA2s. Actin polymerization and talin were evidenced by immunofluorescence and talin was recruited 5 min after both PLA2s stimulation. PKC and PKC-α localization within the cell were increased after 60 min of MT-II and MT-III stimulation. These data suggest that the effect of both PLA2s depends on actin cytoskeleton rearrangements and the activation of PKC, PI3K, and PTK signaling events required for phagocytosis.

Well-differentiated G1 and G2 pancreatic neuroendocrine tumors: a meta-analysis of published expanded DNA sequencing data.

Well-differentiated pancreatic neuroendocrine tumors (PNETs) can be non-functional or functional, e.g. insulinoma and glucagonoma. The majority of PNETs are sporadic, but PNETs also occur in hereditary syndromes, primarily multiple endocrine neoplasia type 1 (MEN1). The Knudson hypothesis stated a second, somatic hit in MEN1 as the cause of PNETs of MEN1 syndrome. In the recent years, reports on genetic somatic events in both sporadic and hereditary PNETs have emerged, providing a basis for a more detailed molecular understanding of the pathophysiology. In this systematic review and meta-analysis, we made a collation and statistical analysis of aggregated frequent genetic alterations and potential driver events in human grade G1/G2 PNETs. A systematic search was performed in concordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) reporting guidelines of 2020.A search in Pubmed for published studies using whole exome, whole genome, or targeted gene panel (+400 genes) sequencing of human G1/G2 PNETs was conducted at the 25th of September 2023. Fourteen datasets from published studies were included with data on 221 patients and 225 G1/G2 PNETs, which were divided into sporadic tumors, and hereditary tumors with pre-disposing germline variants, and tumors with unknown germline status. Further, non-functioning and functioning PNETs were distinguished into two groups for pathway evaluation. The collated genetical analyses were conducted using the 'maftools' R-package. Sporadic PNETs accounted 72.0% (162/225), hereditary PNETs 13.3% (30/225), unknown germline status 14.7% (33/225). The most frequently altered gene was MEN1, with somatic variants and copy number variations in overall 42% (95/225); hereditary PNETs (germline variations in MEN1, VHL, CHEK2, BRCA2, PTEN, CDKN1B, and/or MUTYH) 57% (16/30); sporadic PNETs 36% (58/162); unknown germline status 64% (21/33). The MEN1 point mutations/indels were distributed throughout MEN1. Overall, DAXX (16%, 37/225) and ATRX-variants (12%, 27/225) were also abundant with missense mutations clustered in mutational hotspots associated with histone binding, and translocase activity, respectively. DAXX mutations occurred more frequently in PNETs with MEN1 mutations, p<0.05. While functioning PNETs shared few variated genes, non-functioning PNETs had more recurrent variations in genes associated with the Phosphoinositide 3-kinase, Wnt, NOTCH, and Receptor Tyrosine Kinase-Ras signaling onco-pathways. The somatic genetic alterations in G1/G2 PNETs are diverse, but with distinct differences between sporadic vs. hereditary, and functional vs. non-functional PNETs. Increased understanding of the genetic alterations may lead to identification of more drivers and driver hotspots in the tumorigenesis in well-differentiated PNETs, potentially giving a basis for the identification of new drug targets. (Funded by Novo Nordisk Foundation, grant number NNF19OC0057915).

ABCG2 Mediates Resistance to the Dual EGFR and PI3K Inhibitor MTX-211 in Cancer Cells.

MTX-211 is a first-in-class dual inhibitor of epidermal growth factor receptor (EGFR) and phosphoinositide-3 kinase (PI3K) signaling pathways with a compelling pharmaceutical profile and could enhance the effectiveness of mitogen-activated protein kinase kinase (MEK) inhibitor therapy in colorectal tumors with KRAS mutations. However, the specific mechanisms contributing to the acquired resistance to MTX-211 in human cancers remain elusive. Here, we discovered that the overexpression of the ATP-binding cassette (ABC) drug transporter ABCG2, a prevalent mechanism associated with multidrug resistance (MDR), could diminish the effectiveness of MTX-211 in human cancer cells. We showed that the drug efflux activity of ABCG2 substantially decreased the intracellular accumulation of MTX-211 in cancer cells. As a result, the cytotoxicity and effectiveness of MTX-211 in suppressing the activation of the EGFR and PI3K pathways were significantly attenuated in cancer cells overexpressing ABCG2. Moreover, the enhancement of the MTX-211-stimulated ATPase activity of ABCG2 and the computational molecular docking analysis illustrating the binding of MTX-211 to the substrate-binding sites of ABCG2 offered a further indication for the interaction between MTX-211 and ABCG2. In summary, our findings indicate that MTX-211 acts as a substrate for ABCG2, underscoring the involvement of ABCG2 in the emergence of resistance to MTX-211. This finding carries clinical implications and merits further exploration.

ABBV-319: a CD19-targeting glucocorticoid receptor modulator antibody-drug conjugate therapy for B-cell malignancies

AbstractGlucocorticoids are key components of the standard-of-care treatment regimens for B-cell malignancy. However, systemic glucocorticoid treatment is associated with several adverse events. ABBV-319 is a CD19-targeting antibody-drug conjugate engineered to reduce glucocorticoid-associated toxicities while possessing 3 distinct mechanisms of action (MOA) to increase therapeutic efficacy: (1) antibody-mediated delivery of a glucocorticoid receptor modulator (GRM) payload to activate apoptosis, (2) inhibition of CD19 signaling, and (3) enhanced fragment crystallizable (Fc)–mediated effector function via afucosylation of the antibody backbone. ABBV-319 elicited potent GRM-driven antitumor activity against multiple malignant B-cell lines in vitro, as well as in cell line-derived xenografts and patient-derived xenografts (PDXs) in vivo. Remarkably, a single dose of ABBV-319 induced sustained tumor regression and enhanced antitumor activity compared with repeated dosing of systemic prednisolone at the maximum tolerated dose in mice. The unconjugated CD19 monoclonal antibody (mAb) also displayed antiproliferative activity in a subset of B-cell lymphoma cell lines through the inhibition of phosphoinositide 3-kinase signaling. Moreover, afucosylation of CD19 mAb enhanced Fc-mediated antibody-dependent cellular cytotoxicity. Notably, ABBV-319 displayed superior efficacy compared with afucosylated CD19 mAb in human CD34+ peripheral blood mononuclear cell–engrafted NSG-Tg(Hu-IL15) transgenic mice, demonstrating enhanced antitumor activity when multiple MOAs are enabled. ABBV-319 also showed durable antitumor activity across multiple B-cell lymphoma PDX models, including nongerminal center B-cell diffuse large B-cell lymphoma and relapsed lymphoma after R-CHOP treatment. Collectively, these data support the ongoing evaluation of ABBV-319 in a phase 1 clinical trial.

Potential mitigating impact of a dipeptidyl peptidase-IV inhibitor, vildagliptin, on oxazolone-induced ulcerative colitis: Targeting the role of PI3K/AKT/mTOR and AMPK/Nrf2 signaling pathways

Growing evidence suggests that phosphoinositide 3-kinase (PI3K) and adenosine monophosphate-activated protein kinase (AMPK) signaling cascades are critical in ulcerative colitis (UC) pathophysiology by influencing gut mucosal inflammation. Recently, the coloprotective properties of dipeptidyl peptidase-IV (DPP-IV) inhibitors have emerged. Thus, this study assessed for the first time the potential mitigating impact of a DPP-IV inhibitor, vildagliptin (Vilda), on oxazolone (OXZ)-induced colitis in rats, targeting the role of PI3K/AKT/mTOR and AMPK/Nrf2 pathways. Thirty-two adult Albino rats were divided into four groups: control, Vilda (10 mg/kg/day orally), OXZ (300 µL of 5 % OXZ in 50 % aqueous ethanol solution introduced once into the colon via catheter), and Vilda+OXZ. Inflammatory cytokines (interleukin 13, tumor necrosis factor-α, interleukin 10), oxidative/endoplasmic reticulum stress markers (myeloperoxidase, reduced glutathione, catalase, CHOP), mitochondrial reactive oxygen species, adenosine triphosphate levels, and mitochondrial transmembrane potential were estimated. p-AMPK, p-AKT, beclin-1, and SQSTM1 levels were immunoassayed. Nrf2, PI3K, and mTOR expression levels were quantified using the real-time polymerase chain reaction. Furthermore, p-NF-ĸBp65 and LC3II immunoreactivity were evaluated. Vilda administration effectively ameliorated OXZ-induced colitis, as evidenced by the reduced Disease Activity Index, macroscopic colon damage score, colon weight/length ratio, ulcer index, and histopathological and electron microscopic changes in the colon tissues. Vilda treatment also counteracted OXZ-triggered inflammation, oxidative/endoplasmic reticulum stress, mitochondrial dysfunction, and enhanced autophagy in the colon. Vilda substantially suppressed PI3K/AKT/mTOR and activated the AMPK/Nrf2 pathway. Vilda has potent coloprotective and anti-ulcerogenic properties, primarily attributed to its antiinflammatory, antioxidant, and modulatory impact on mitochondrial dysfunction and autophagy activity. These effects were mostly mediated by suppressing PI3K/AKT/mTOR and activating AMPK/Nrf2 signaling cascades, suggesting a potential role of Vilda in UC therapy.

Principles in the Management of Glioblastoma.

Glioblastoma, the most aggressive and common malignant primary brain tumour, is characterized by infiltrative growth, abundant vascularization, and aggressive clinical evolution. Patients with glioblastoma often face poor prognoses, with a median survival of approximately 15 months. Technological progress and the subsequent improvement in understanding the pathophysiology of these tumours have not translated into significant achievements in therapies or survival outcomes for patients. Progress in molecular profiling has yielded new omics data for a more refined classification of glioblastoma. Several typical genetic and epigenetic alterations in glioblastoma include mutations in genes regulating receptor tyrosine kinase (RTK)/rat sarcoma (RAS)/phosphoinositide 3-kinase (PI3K), p53, and retinoblastoma protein (RB) signalling, as well as mutation of isocitrate dehydrogenase (IDH), methylation of O6-methylguanine-DNA methyltransferase (MGMT), amplification of epidermal growth factor receptor vIII, and codeletion of 1p/19q. Certain microRNAs, such as miR-10b and miR-21, have also been identified as prognostic biomarkers. Effective treatment options for glioblastoma are limited. Surgery, radiotherapy, and alkylating agent chemotherapy remain the primary pillars of treatment. Only promoter methylation of the gene MGMT predicts the benefit from alkylating chemotherapy with temozolomide and it guides the choice of first-line treatment in elderly patients. Several targeted strategies based on tumour-intrinsic dominant signalling pathways and antigenic tumour profiles are under investigation in clinical trials. This review explores the potential genetic and epigenetic biomarkers that could be deployed as analytical tools in the diagnosis and prognostication of glioblastoma. Recent clinical advancements in treating glioblastoma are also discussed, along with the potential of liquid biopsies to advance personalized medicine in the field of glioblastoma, highlighting the challenges and promises for the future.

Identification and analysis of key circRNAs in the mouse embryonic ovary provides insight into primordial follicle development.

CircRNAs are a class of noncoding RNAs with tissue- and development-specific expression characteristics. In many mammals, primordial follicle development begins in the embryonic stage. However, the study of circRNAs in primordial follicle development in mice has not been reported. In this study, ovaries were collected from mouse foetuses at 15.5 days post coitus (dpc) and 17.5 dpc, which are two key stages of primordial follicle development. A total of 4785 circRNAs were obtained by using RNA-seq.Of these, 83 differentially expressed circRNAs were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that these differential circRNAs were mainly involved in the regulation of reproductive development. Through qRT-PCR, back-splice sequence detection and enzyme digestion protection experiments, we found that circ-009346, circ-014674, circ-017054 and circ-008296 were indeed circular. Furthermore, circ-009346, circ-014674 and circ-017054 were identified as three key circRNAs by analysing their expression in the ovaries of mice at different developmental stages. The circRNA-miRNA-mRNA interaction network was constructed and validated for target miRNA and mRNA using qRT-PCR. The interacting genes circ-009346, circ-014674, and circ-017054 were subjected to KEGG enrichment analysis. We found that circ-014674 may participate in the assembly and reserve of primordial follicles through oestrogen and the Janus kinase (JAK) signal transducer and activator of transcription (STAT) signalling pathway (JAK-SATA). Circ-009346 and circ-017054 may have similar functions and are involved in the activation and growth of primordial follicles through the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) signalling pathways. Based on our findings, three circRNAs associated with primordial follicle development were identified, and their potential mechanisms of regulating primordial follicle development were revealed. These findings will help us better understand the molecular mechanism of circRNAs in primordial follicles and provide important references and targets for the development of primordial follicles.

Total polyphenols of Cydonia oblonga inhibited proliferation and migration of renal cancer cells by PI3K/Akt/mTOR pathway

The mechanism of total polyphenols of Cydonia oblonga Miller(TPCOM) against kidney cancer was elucidated through a combination of network pharmacology, bioinformatics, and experimental verification. The active polyphenolic compounds from C. oblonga were screened by network pharmacological techniques and kidney cancer-related targets were collected through the database. The differential gene expression analysis was performed on RNA sequencing data from tumor tissue and normal tissue of kidney cancer patients obtained from the Gene Expression Omnibus(GEO) database. The results of network pharmacology predictions and differential gene expression analysis were used to identify the core genes targeted by TPCOM in kidney cancer. Survival analysis was conducted to identify key targets that could impact patient survival, followed by Kyoto Encyclopedia of Genes and Genomes(KEGG) and Gene Ontology(GO) enrichment analyses. Cell proliferation and activity experiments(cell counting kit-8) were conducted using TPCOM at concentrations ranging from 20 to 640 μg·mL~(-1) on 786-O and Renca cells. Additionally, TPCOM at concentrations of 40, 80, and 160 μg·mL~(-1) was applied to kidney cancer cells to assess its effect on cell migration and its regulation of protein expression levels related to the protein kinase B(Akt), mammalian target of rapamycin(mTOR), and phosphoinositide 3-kinase(PI3K) signaling pathways. Network pharmacology predicted eight active polyphenolic compounds from C. oblonga. Survival analysis revealed 15 significantly differentially expressed genes in kidney cancer that were affected by TPCOM and had a significant impact on patient survival. KEGG and GO analysis results indicated that these 15 targets were primarily associated with the PI3K/Akt signaling pathway, cell migration, and proliferation. The results showed that TPCOM could inhibit the proliferation of 786-O and Renca cells, with IC_(50) values of 121.4 and 137.9 μg·mL~(-1), respectively. TPCOM was also found to inhibit the migration of these cells and suppress the PI3K/Akt/mTOR signaling pathway. TPCOM may exert its anti-kidney cancer effects by inhibiting the activation of the PI3K/Akt/mTOR signaling pathway, thereby restraining the proliferation and migration of kidney cancer cells. This study provides a foundation for the research on the anti-tumor effects of natural product C. oblonga, particularly in Xinjiang, and holds significance for further promoting its development and utilization.

Abstract A052: Dissecting the immune regulatory mechanisms of distinct PI3K alterations in invasive lobular carcinoma

Abstract Immunotherapy has been far less effective in breast cancer compared to other cancer types, with only a small fraction of patients having clinical benefit. Historically, invasive lobular carcinomas (ILC), the second most common histological subtype of breast cancer, have been categorized as immunological cold tumors, but recent studies suggest that ILCs may recruit a myeloid-rich immunosuppressive immune landscape. Cancer cell intrinsic features such as the genetic makeup of tumor cells can dictate the spatial distribution, composition and activation state of immune cells, which can exert both anti-tumor and pro-tumor activities and affect disease progression and immunotherapy response. Genetic aberration in key genes of the phosphoinositide-3 kinase (PI3K) signaling pathway are observed in &amp;gt;50% of primary ILCs. The overall aim of this project is to determine whether genetic aberrations in key genes of the PI3K pathway regulate the composition and functional state of the immune landscape, and whether this influences the clinical benefit of immunomodulatory strategies in ILC patients. To dissect the immune regulatory mechanisms of distinct PI3K alterations we have used transgenic ILC mouse models, in which immune profiling studies by flow cytometry and immunohistochemistry revealed that distinct PI3K alterations in cancer cells differentially affect the tumor immune landscape. With some mutations driving a myeloid-rich tumor microenvironment, whereas the immune landscape of tumors harboring other PI3K mutations is dominated by lymphoid cells. To understand the observed cancer genotype-immunophenotypes mechanistically, we have performed single-cell RNA sequencing and secretome analysis to assess cellular communication between the cancer cells and the immune system. We identified key differences in ligand-receptor interactions and secreted signaling that can explain the influx of different immunosuppressive immune cell types in the tumor microenvironment of murine ILCs. We are currently investigating whether therapeutic targeting of immunosuppression is a feasible strategy for PI3K-altered ILC tumors with a tumor-promoting immune landscape. Shedding light on the mechanisms that govern the diversity and function of immune cells in the tumor microenvironment will provide a greater understanding of interpatient heterogeneity, and will pave the way for the development of novel and more tailored immunomodulatory strategies for ILC patients. Citation Format: Antoinette van Weverwijk, Michael Schubert, Joseph Siefert, Martine van Miltenburg, Kim Vrijland, Julia Houthuijzen, Anne Stunnenberg, Cheei-Sing Hau, Lodewyk Wessels, Jos Jonkers, Karin E de Visser. Dissecting the immune regulatory mechanisms of distinct PI3K alterations in invasive lobular carcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A052.

E3 ubiquitin ligase casitas B-lineage lymphoma-b modulates T-cell anergic resistance via phosphoinositide 3-kinase signaling in patients with immune thrombocytopenia

BackgroundThe E3 ubiquitin ligase casitas B-lineage lymphoma-b (CBLB) is a newly identified component of the ubiquitin-dependent protein degradation system and is considered an important negative regulator of immune cells. CBLB is essential for establishing a threshold of T-cell activation and regulating peripheral T-cell tolerance through various mechanisms. However, the involvement of CBLB in the pathogenesis of immune thrombocytopenia (ITP) is unknown. ObjectivesWe aimed to investigate the expression and role of CBLB in CD4+ T cells obtained from patients with ITP through quantitative proteomics analyses. MethodsCD4+ T cells were transfected with adenoviral vectors overexpressing CBLB to clarify the effect of CBLB on anergic induction of T cells in patients with ITP. DNA methylation levels of the CBLB promoter and 5′ untranslated region (UTR) in patient-derived CD4+ T cells were detected via MassARRAY EpiTYPER assay (Agena Bioscience). ResultsCD4+ T cells from patients with ITP showed resistance to anergic induction, highly activated phosphoinositide 3-kinase–protein kinase B (AKT) signaling, decreased CBLB expression, and 5′ UTR hypermethylation of CBLB. CBLB overexpression in T cells effectively attenuated the elevated phosphorylated protein kinase B level and resistance to anergy. Low-dose decitabine treatment led to significantly elevated levels of CBLB expression in CD4+ T cells from 7 patients showing a partial or complete response. ConclusionThese results indicate that the 5′ UTR hypermethylation of CBLB in CD4+ T cells induces resistance to T-cell anergy in ITP. Thus, the upregulation of CBLB expression by low-dose decitabine treatment may represent a potential therapeutic approach to ITP.