The PI3K/AKT/mTOR signaling pathway in breast cancer: Review of clinical trials and latest advances.

Breast cancer (BC) is the most commonly diagnosed cancer and the leading cause of cancer mortality in women. As the phosphatidylinositol 3-kinase (PI3K) signaling pathway is involved in a wide range of physiological functions of cells including growth, proliferation, motility, and angiogenesis, any alteration in this axis could induce oncogenic features; therefore, numerous preclinical and clinical studies assessed agents able to inhibit the components of this pathway in BC patients. To the best of our knowledge, this is the first study that analyzed all the registered clinical trials investigating safety and efficacy of the PI3K/AKT/mTOR axis inhibitors in BC. Of note, we found that the trends of PI3K inhibitors in recent years were superior as compared with the inhibitors of either AKT or mTOR. However, most of the trials entering phase III and IV used mTOR inhibitors (majorly Everolimus) followed by PI3K inhibitors (majorly Alpelisib) leading to the FDA approval of these drugs in the BC context. Despite favorable efficacies, our analysis shows that the majority of trials are utilizing PI3K pathway inhibitors in combination with hormone therapy and chemotherapy; implying monotherapy cannot yield huge clinical benefits, at least partly, due to the activation of compensatory mechanisms. To emphasize the beneficial effects of these inhibitors in combined-modal strategies, we also reviewed recent studies which investigated the conjugation of nanocarriers with PI3K inhibitors to reduce harmful toxicities, increase the local concentration, and improve their efficacies in the context of BC therapy.

Kinetochore scaffold 1 downregulation suppressed the development of non-small cell lung cancer by inactivating the phosphatidylinositol 3 kinase/protein kinase B (AKT)/nuclear factor-kappa B pathway.

Kinetochore scaffold 1 (KNL1) is indispensable for generating motile micro-tubule attachments and isolating chromosomes. KNL1 is highly expressed in multiple middle-route tissues and promotes tumor development. However, how it functions in non-small cell lung cancer (NSCLC) is unclear. Real-time quantitative PCR (RT-qPCR) and Western blotting (WB) were used to determine KNL1 expression in NSCLC tissues and cells. The sh-KNL1 or oe-KNL1 was transfected into NSCLC cells. The colony formation assay, cell counting kit-8 (CCK-8) assay, and flow cytometry were used to evaluate cell proliferation and apoptosis. A transwell assay was used to monitor invasion and migration. The CCK-8 assay was used to measure NSCLC cell sensitivity to chemotherapy drugs. WB confirmed the protein levels of apoptosis-related proteins, cell cycle-associated proteins, and the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/nuclear factor kappaB (NF-κB) pathway. A PI3K/AKT/NF-κB pathway inhibitor was used to intervene in NSCLC cell transfection along with oe-KNL1, thus revealing the function of the pathway in carcinogenicity mediated by KNL1. In result KNL1 expression was substantially increased in NSCLC tissues and cells. High-level KNL1 expression is related to the poor prognosis of NSCLC patients. KNL1 silencing bolstered promoted NSCLC cell apoptosis and inhibited proliferation, cell cycle progression, invasion, and EMT, whereas KNL1 silencing had the opposite effect. KNL1 knockdown increased NSCLC cell sensitivity to chemical drugs. KNL1 promoted PI3K/AKT/NF-κB pathway activation, while PI3K/AKT/NF-κB pathway inhibition weakened the procancer effect mediated by KNL1 overexpression but had little influence on KNL1 levels. We conclude that KNL1 activates the PI3K/AKT/NF-κB pathway to increase NSCLC progression and attenuate NSCLC sensitivity to chemotherapy drugs.

Effect of miR-1297 on Kidney Injury in Rats with Diabetic Nephropathy through the PTEN/PI3K/AKT Pathway.

PURPOSE: This study aimed to determine the influence of miR-1297 on kidney injury in rats with diabetic nephropathy (DN) and its causal role. METHODS: A DN rat model was established through right kidney resection and intraperitoneal injection of streptozotocin (STZ). Sham rats did not undergo right kidney resection or STZ injection. The DN rats were divided into the DN model and antagomiR-1297 treatment groups. Kidney morphology was observed using hematoxylin and eosin staining. Renal function indices, including blood urea nitrogen (BUN), serum creatinine (SCr), and urinary protein, were measured using kits. Levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1ß, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were determined through enzyme-linked immunosorbent assay (ELISA). Fibrin (FN), collagen type I (Col I), and α-smooth muscle actin (α-SMA) were assessed through western blotting and real-time reverse transcription-polymerase chain reaction. Apoptosis was detected using terminal deoxynucleotidyl transferase dUTP nick end labeling staining. miR-1297 targets were predicted using bioinformatic software and verified through luciferase reporter assay. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN)/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway expression was analyzed through western blotting. RESULTS: AntagomiR-1297 reduced BUN (p = 0.005), SCr (p = 0.012), and urine protein (p < 0.001) levels and improved kidney tissue morphology. It prevented renal interstitial fibrosis by decreasing FN, Col I, and α-SMA protein levels (all p < 0.001). AntagomiR-1297 increased SOD (p = 0.001) and GSH-Px (p = 0.002) levels. Additionally, it reduced levels of cell inflammatory factors, including TNF-α, IL-6, and IL-1ß (all p < 0.001), and alleviated apoptosis (p < 0.001) in rat kidney tissue with DN. miR-1297 was pinpointed as a target for PTEN. AntagomiR-1297 increased PTEN expression and suppressed PI3K and AKT phosphorylation (all p < 0.001). CONCLUSIONS: AntagomiR-1297 can mitigate renal fibrosis, renal inflammation, apoptosis, and oxidative stress levels through the PTEN/PI3K/AKT pathway.

Effects of electroacupuncture on the PI3K/Akt/CREB signaling pathway and hippocampal neuronal apoptosis in diabetic cognitive impairment rats. / ç”µé’ˆå¯¹ç³–å°¿ç— è®¤çŸ¥åŠŸèƒ½éšœç¢å¤§é¼ PI3K/Akt/CREBä¿¡å·é€šè·¯å’Œæµ·é©¬ç¥žç»å ƒå‡‹äº¡çš„å½±å“.

OBJECTIVES: To observe the effects of electroacupuncture (EA) on the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/cAMP response element binding protein (CREB) signaling pathway-related proteins and hippocampal neuron apoptosis in diabetic cognitive impairment (DCI) rats, and to explore the mechanisms of EA in treating DCI. METHODS: Adult male SD rats were randomly divided into normal, model, and EA groups, with 12 rats in each group. The animal model of DCI was replicated using a high-fat, high-sugar diet combined with low-dose streptozotocin. The EA group received EA stimulation at "Yishu" (EX-B6), "Zusanli" (ST36), "Baihui" (GV20), and "Dazhui" (GV14). Blood glucose contents of the rats in each group were measured. The Morris water maze test was used to assess the learning and memory abilities of rats. Transmission electron microscopy was used to observe the ultrastructure of hippocampal CA1 neurons. Nissl staining was used to observe the pathological changes in hippocampal CA1 neurons. TUNEL staining was used to detect the apoptosis in hippocampal CA1 neurons. Western blot was used to detect the protein expression levels of p-PI3K/PI3K and p-Akt/Akt, as well as CREB, p-CREB, cysteine aspartate pro-tease (Caspase)-3, B-cell lymphoma-2 (Bcl-2), and Bcl-2 related X protein (Bax) in the hippocampal tissue of rats. RESULTS: Compared with the normal group, the rats' random blood glucose contents were significantly increased (P<0.01), the escape latency prolonged (P<0.01), and the original platform crossing counts reduced (P<0.01) in the model group. Significant damage to hippocampal CA1 neurons, a significantly increased neuronal apoptosis index (P<0.01), decreased ratio of p-PI3K/PI3K and p-Akt/Akt and expression of CREB, p-CREB and Bcl-2 proteins, increased expression of Caspase-3 and Bax proteins (P<0.01) were observed in the hippocampal tissue of rats in the model group. Compared with the model group, the rats in the EA group showed decreased random blood glucose content (P<0.01), shortened escape latency (P<0.01), increased original platform crossing counts (P<0.01), improved quantity and pathological morphology and ultrastructure of hippocampal CA1 neurons, reduced neuronal apoptosis index (P<0.01), increased ratio of p-PI3K/PI3K and p-Akt/Akt, and expression of CREB, p-CREB and Bcl-2 proteins (P<0.05, P<0.01) in the hippocampal tissue, and decreased expression of Caspase-3 and Bax proteins (P<0.01). CONCLUSIONS: EA can improve the learning and memory abilities of rats with DCI, and the mechanism may be related to the regulation of the expression of PI3K/Akt/CREB signaling pathway-related proteins, which attenuates the neuronal apoptosis in the hippocampus of rats, and improves the neural function.

Non-catalytic role of phosphoinositide 3-kinase in mesenchymal cell migration through non-canonical induction of p85ß/AP2-mediated endocytosis.

Class IA phosphoinositide 3-kinase (PI3K) galvanizes fundamental cellular processes such as migration, proliferation, and differentiation. To enable these multifaceted roles, the catalytic subunit p110 utilizes the multi-domain, regulatory subunit p85 through its inter SH2 domain (iSH2). In cell migration, its product PI(3,4,5)P3 generates locomotive activity. While non-catalytic roles are also implicated, underlying mechanisms and their relationship to PI(3,4,5)P3 signaling remain elusive. Here, we report that a disordered region of iSH2 contains AP2 binding motifs which can trigger clathrin and dynamin-mediated endocytosis independent of PI3K catalytic activity. The AP2 binding motif mutants of p85 aberrantly accumulate at focal adhesions and increase both velocity and persistency in fibroblast migration. We thus propose the dual functionality of PI3K in the control of cell motility, catalytic and non-catalytic, arising distinctly from juxtaposed regions within iSH2.

A novel phthalein component ameliorates neuroinflammation and cognitive dysfunction by suppressing the CXCL12/CXCR4 axis in rats with vascular dementia.

ETHNOPHARMACOLOGICAL RELEVANCE: Chuanxiong, a plant of the Umbelliferae family, is a genuine medicinal herb from Sichuan Province. Phthalides are one of its main active components and exhibit good protective effect against cerebrovascular diseases. However, the mechanism by which phthalides exert neuroprotective effects is still largely unclear. AIM OF THE STUDY: In this study, we extracted a phthalein component (named as QBT) from Ligusticum Chuanxiong, and investigated its neuroprotective effects against vascular dementia (VaD) rats and the underlying mechanism, focusing on the chemokine 12 (CXCL12)/chemokine (C-X-C motif) receptor 4 (CXCR4) axis. METHODS: A rat model of VaD was established, and treated with QBT. Cognitive dysfunction in VaD rats was assessed using the Y-maze, new object recognition, and Morris water maze tests. Neuronal damage and inflammatory response in VaD rats were examined through Nissl staining, immunofluorescence, enzyme-linked immunospecific assay, and western blotting analysis. Furthermore, the effects of QBT on CXCL12/CXCR4 axis and its downstream signaling pathways, Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/nuclear factor-κB (NF-κB), were investigated in VaD rats and BV2 microglial cells exposed to oxygen glucose deprivation. RESULTS: QBT significantly alleviated cognitive dysfunction and neuronal damage in VaD rats, along with inhibition of VaD-induced over-activation of microglia and astrocytes and inflammatory response. Moreover, QBT exhibited anti-inflammatory effects by inhibiting the CXCL12/CXCR4 axis and its downstream JAK2/STAT3 and PI3K/AKT/NF-κB pathways, thereby attenuating the neuroinflammatory response both in vivo and in vitro. CONCLUSION: QBT effectively mitigated neuronal damage and cognitive dysfunction in VaD rats, exerting neuroprotective effects by suppressing neuroinflammatory response through inhibition of the CXCL12/CXCR4 axis.

Xanthoceras sorbifolium leaves alleviate hyperuricemic nephropathy by inhibiting the PI3K/AKT signaling pathway to regulate uric acid transport.

ETHNOPHARMACOLOGICAL RELEVANCE: In China, Xanthoceras sorbifolium Bunge was first documented as "Wen Guan Hua" in the "Jiu Huang Ben Cao" in 1406 A.D. According to the "National Compilation of Chinese Herbal Medicine," X. sorbifolium leaves are sweet and flat in nature and can dispel wind and dampness, suggesting that their extract can be used to treat rheumatoid arthritis. X. sorbifolium Bunge has also been used to treat arteriosclerosis, hyperlipidemia, hypertension, chronic hepatitis, and rheumatism, complications associated with hyperuricemic nephropathy (HN), a condition characterized by kidney damage resulting from high levels of uric acid (UA) in the blood. AIM OF THE STUDY: The purpose of this study was to investigate the effects and underlying mechanisms of a 70% ethanol extract from X. sorbifolium leaves (EX) in alleviating HN. MATERIALS AND METHODS: A mouse model of hyperuricemia was established to initially evaluate the hypouricemic effects and determine the effective dose of EX. Phytochemical analyses were conducted using ultra high-performance liquid chromatography and liquid chromatography-mass spectroscopy. The potential key pathways of EX in the alleviation of HN were inferred using network pharmacology and bioinformatics. An HN rat model was then established, and experiments including biomarker detection, western blotting, reverse transcription quantitative polymerase chain reaction, immunohistochemical and Masson's trichrome staining, and transmission electron microscopy were conducted to evaluate the effect of EX on UA transporter expression in vitro. RESULTS: Network pharmacology and bioinformatics analyses revealed that the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway was the key pathway for the alleviation of HN progression by EX. EX treatment reduced serum biomarkers in HN rats, downregulated the expression of p-PI3K, p-AKT, glucose transporter 9 (GLUT9), urate transporter 1 (URAT1), Collagen I, matrix metalloproteinase (MMP)-2, and MMP-9, and upregulated the expression of ATP binding cassette subfamily G member 2 (ABCG2) to improve renal interstitial fibrosis in HN rats. A high content of both quercitrin and cynaroside were identified in EX; their administration inhibited the increased expression of GLUT9 and URAT1 in damaged HK-2 cells. CONCLUSION: Our study provides evidence that EX alleviates HN. The potential mechanism underlying this effect may be the regulation of UA transporters, such as GLUT9 and URAT1, by limiting the activation of the PI3K/AKT signaling pathway to improve renal injury.

The human adenovirus PI3K-Akt activator E4orf1 is targeted by the tumor suppressor p53.

Human adenoviruses (HAdV) are classified as DNA tumor viruses due to their potential to mediate oncogenic transformation in non-permissive mammalian cells and certain human stem cells. To achieve transformation, the viral early proteins of the E1 and E4 regions must block apoptosis and activate proliferation: the former predominantly through modulating the cellular tumor suppressor p53 and the latter by activating cellular pro-survival and pro-metabolism protein cascades, such as the phosphoinositide 3-kinase (PI3K-Akt) pathway, which is activated by HAdV E4orf1. Focusing on HAdV-C5, we show that E4orf1 is necessary and sufficient to stimulate Akt activation through phosphorylation in H1299 cells, which is not only hindered but repressed during HAdV-C5 infection with a loss of E4orf1 function in p53-positive A549 cells. Contrary to other research, E4orf1 localized not only in the common, cytoplasmic PI3K-Akt-containing compartment, but also in distinct nuclear aggregates. We identified a novel inhibitory mechanism, where p53 selectively targeted E4orf1 to destabilize it, also stalling E4orf1-dependent Akt phosphorylation. Co-IP and immunofluorescence studies showed that p53 and E4orf1 interact, and since p53 is bound by the HAdV-C5 E3 ubiquitin ligase complex, we also identified E4orf1 as a novel factor interacting with E1B-55K and E4orf6 during infection; overexpression of E4orf1 led to less-efficient E3 ubiquitin ligase-mediated proteasomal degradation of p53. We hypothesize that p53 specifically subverts the pro-survival function of E4orf1-mediated PI3K-Akt activation to protect the cell from metabolic hyper-activation or even transformation.IMPORTANCEHuman adenoviruses (HAdV) are nearly ubiquitous pathogens comprising numerous subtypes that infect various tissues and organs. Among many encoded proteins that facilitate viral replication and subversion of host cellular processes, the viral E4orf1 protein has emerged as an intriguing yet under-investigated player in the complex interplay between the virus and its host. Nonetheless, E4orf1 has gained attention as a metabolism activator and oncogenic agent, while recent research is showing that E4orf1 may play a more important role in modulating the cellular pathways such as phosphoinositide 3-kinase-Akt-mTOR. Our study reveals a novel and general impact of E4orf1 on host mechanisms, providing a novel basis for innovative antiviral strategies in future therapeutic settings. Ongoing investigations of the cellular pathways modulated by HAdV are of great interest, particularly since adenovirus-based vectors actually serve as vaccine or gene vectors. HAdV constitute an ideal model system to analyze the underlying molecular principles of virus-induced tumorigenesis.

Plasmodium falciparum selectively degrades α-spectrin of infected erythrocytes after invasion.

Remodeling the erythrocyte membrane and skeleton by the malarial parasite Plasmodium falciparum is closely associated with intraerythrocytic development. However, the mechanisms underlying this association remain unclear. In this study, we present evidence that erythrocytic α-spectrin, but not ß-spectrin, was dynamically ubiquitinated and progressively degraded during the intraerythrocytic development of P. falciparum, from the ring to the schizont stage. We further observed an upregulated expression of P. falciparum phosphatidylinositol 3-kinase (PfPI3K) in the infected red blood cells during the intraerythrocytic development of the parasite. The data indicated that PfPI3K phosphorylated and activated erythrocytic ubiquitin-protein ligase, leading to increased α-spectrin ubiquitination and degradation during P. falciparum development. We further revealed that inhibition of the activity of PfPI3K impaired P. falciparum development in vitro and Plasmodium berghei infectivity in mice. These findings collectively unveil an important mechanism of PfPI3K-ubiquitin-mediated degradation of α-spectrin during the intraerythrocytic development of Plasmodium species. Proteins in the PfPI3K regulatory pathway are novel targets for effective treatment of severe malaria. IMPORTANCE: Plasmodium falciparum is the causative agent of severe malaria that causes millions of deaths globally. The parasite invades human red blood cells and induces a cascade of alterations in erythrocytes for development and proliferation. Remodeling the host erythrocytic cytoskeleton is a necessary process during parasitization, but its regulatory mechanisms remain to be elucidated. In this study, we observed that erythrocytic α-spectrin is selectively degraded after P. falciparum invasion, while ß-spectrin remained intact. We found that the α-spectrin chain was profoundly ubiquitinated by E3 ubiquitin ligase and degraded by the 26S proteasome. E3 ubiquitin ligase activity was regulated by P. falciparum phosphatidylinositol 3-kinase (PfPI3K) signaling. Additionally, blocking the PfPI3K-ubiquitin-proteasome pathway in P. falciparum-infected red blood cells reduced parasite proliferation and infectivity. This study deepens our understanding of the regulatory mechanisms of host and malarial parasite interactions and paves the way for the exploration of novel antimalarial drugs.

PI3Kα inhibitor GNE-493 triggers antitumor immunity in murine lung cancer by inducing immunogenic cell death and activating T cells.

Phosphatidylinositol 3-kinase (PI3K) is frequently hyperactivated in cancer, playing pivotal roles in the pathophysiology of both malignant and immune cells. The impact of PI3K inhibitors on the tumor microenvironment (TME) within lung cancer remains largely unknown. In this study, we explored the regulatory effects of GNE-493, an innovative dual inhibitor of PI3K and mammalian target of rapamycin (mTOR), on the TME of lung cancer. First, through the analysis of The Cancer Genome Atlas-lung squamous cell carcinoma (LUSC) cohort, we found PIK3CA to be related to CD8 T cells, which may affect the overall survival rate of patients by affecting CD8 function. We herein demonstrated that GNE-493 can significantly inhibit tumor cell proliferation and promote cell apoptosis while increasing the expression of the immunogenic death-related molecules CRT and HSP70 using in vitro cell proliferation and apoptosis experiments on the murine KP lung cancer cell line and human A549 lung cancer cell line. Next, through the establishment of an orthotopic tumor model in vivo, it was found that after GNE-493 intervention, the infiltration of CD4+ and CD8+ T cells in mouse lung tumor was significantly increased, and the expression of CRT in tumors could be induced to increase. To explore the mechanisms underlying PI3K inhibition-induced changes in the TME, the gene expression differences of T cells in the control group versus GNE-493-treated KP tumors were analyzed by RNA-seq, and the main effector pathway of anti-tumor immunity was identified. The IFN/TNF family molecules were significantly upregulated after GNE-493 treatment. In summary, our findings indicate that GNE-493 promotes immunogenic cell death in lung cancer cells, and elucidates its regulatory impact on molecules associated with the adaptive immune response. Our study provides novel insights into how PI3K/mTOR inhibitors exert their activity by modulating the tumor-immune interaction.

Combination of ethyl acetate fraction from Calotropis gigantea stem bark and sorafenib induces apoptosis in HepG2 cells.

The cytotoxicity of the ethyl acetate fraction of the Calotropis gigantea (L.) Dryand. (C. gigantea) stem bark extract (CGEtOAc) has been demonstrated in many types of cancers. This study examined the improved cancer therapeutic activity of sorafenib when combined with CGEtOAc in HepG2 cells. The cell viability and cell migration assays were applied in HepG2 cells treated with varying concentrations of CGEtOAc, sorafenib, and their combination. Flow cytometry was used to determine apoptosis, which corresponded with a decline in mitochondrial membrane potential and activation of DNA fragmentation. Reactive oxygen species (ROS) levels were assessed in combination with the expression of the phosphatidylinositol-3-kinase (PI3K)/ protein kinase B (Akt)/ mammalian target of rapamycin (mTOR) pathway, which was suggested for association with ROS-induced apoptosis. Combining CGEtOAc at 400 µg/mL with sorafenib at 4 µM, which were their respective half-IC50 concentrations, significantly inhibited HepG2 viability upon 24 h of exposure in comparison with the vehicle and each single treatment. Consequently, CGEtOAc when combined with sorafenib significantly diminished HepG2 migration and induced apoptosis through a mitochondrial-correlation mechanism. ROS production was speculated to be the primary mechanism of stimulating apoptosis in HepG2 cells after exposure to a combination of CGEtOAc and sorafenib, in association with PI3K/Akt/mTOR pathway suppression. Our results present valuable knowledge to support the development of anticancer regimens derived from the CGEtOAc with the chemotherapeutic agent sorafenib, both of which were administered at half-IC50, which may minimize the toxic implications of cancer treatments while improving the therapeutic effectiveness toward future medical applications.

Tanshinone IIA Regulates Synaptic Plasticity in Mg2+-Free-Induced Epileptic Hippocampal Neurons via the PI3K/Akt Signaling Pathway.

BACKGROUND: Tanshinone IIA (TSIIA) is an element of the effective ingredients of Salvia miltiorrhiza Bunge (Labiatae), exhibits a significant therapeutic effect in brain neuroprotection. The focus of this study was the examination of synaptic plasticity of in Mg2+-free-induced epileptic hippocampus neurons and how TSIIA protects against it. METHODS: The purity of the primary hippocampal neurons extracted from Sprague Dawley rats was assessed within 24 hours by microtubule-associated protein (MAP2) immunofluorescence staining. A hippocampal neuron model for Mg2+-free-induced spontaneous recurrent epileptiform discharge was developed, five experimental groups were then randomized: blank (Blank), model (Model), TSIIA (TSIIA, 20 µM), LY294002 (LY294002, 25 µM), and TSIIA+LY294002 (TSIIA+LY294002, 20 µM+25 µM). FIJI software was used to examine variations of neurite complexity, total length of hippocampal neurons, number of primary dendrites and density of dendritic spines. Developmental regulation brain protein (Drebrin) and brain-derived neurotrophic factor (BDNF) expression was evaluated using immunofluorescence staining and the relative expression of phospho-protein kinase B (p-Akt)/Akt, BDNF, synaptophysin (SYN) and postsynaptic density 95 (PSD-95) determined by Western blot. RESULTS: In contrast to the model group, TSIIA drastically reduced damage to synaptic plasticity of hippocampal neurons caused by epilepsy (p < 0.05). The TSIIA group showed a significant increase in the relative expression of PSD-95, SYN, BDNF, and p-Akt/Akt (p < 0.01). CONCLUSIONS: TSIIA was effective in reducing harm to the synaptic plasticity of hippocampal neurons induced by persistent status epilepticus, with the possible mechanism being regulation of the phosphatidylinositol 3-kinase 56 (PI3K)/Akt signaling pathway.

[LncRNA SNHG11 promotes malignant progression of colorectal cancer cells through the PI3K/Akt/mTOR signaling pathway].

Objective: To investigate the effects of lncRNA SNHG11 on proliferation, migration, invasion and apoptosis of colorectal cancer cancer cells and possible mechanisms. Methods: qRT-PCR was performed to detect the expression level of lncRNA SNHG11 in colorectal cancer tissues and its related cell lines. The correlation between SNHG11 expression and clinical prognosis of patients was assessed by bioinformatics techniques. Cultured CRC cell lines were transfected with shCtrl (shCtrl group), shSNHG11#1 (shSNHG11#1 group), shSNHG11#2 (shSNHG11#2 group), Control cDNA (Control cDNA group), and SNHG11 cDNA (SNHG11 cDNA), respectively. Thiazolyl blue (MTT), clone formation assay, Transwell assay, cell scratch assay, and flow cytometry were used to detect the proliferation, migration, invasion, and apoptosis of CRC cells in each group. Western protein blotting was used to detect the expression of relevant proteins in each group, and the effect of lncRNA SNHG11 knockdown on the growth of tumour cells in vivo was analysed by nude mice tumouring assay. Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signalling pathway inhibitor LY294002 was used for rescue experiments. Results: The expression of lncRNA SNHG11 was significantly higher in colorectal cancer cells and tissues than in normal tissues (P<0.05). Survival analysis showed that the expression level of SNHG11 was not statistically associated with CRC survival (P>0.05). shSNHG11#2 group compared with shCtrl group. MTT OD490/570 values decreased, the number of CRC cell clones decreased, the number of Transwell cells decreased, the area of cell scratch decreased, and the apoptosis rate increased (P<0.05). The mesenchymal markers matrix metalloproteinase (MMP9), N-cadherin and vimentin were significantly reduced, and the expression of the epithelial marker E-cadherin was upregulated. The expression of anti-apoptotic proteins Bcl-2 and Bcl-xl was decreased, and the expression of pro-apoptotic protein Bax was increased (P<0.05).In vivo experiments showed that lncRNA SNHG11 knockdown inhibited the growth of colorectal cancer cells, and the expression of Ki67 was reduced in tumours (P<0.05). LncRNA SNHG11 knockdown inhibited the expression of p-PI3K, p-Akt and p-mTOR.The PI3K/Akt/mTOR signaling pathway inhibitor LY294002 was able to restore the malignant cytological progression of colorectal cancer cells induced by the overexpression of lncRNA SNHG11. Conclusions: LncRNA SNHG11 is highly expressed in colorectal cancer. lncRNA SNHG11 can promote the malignant progression of colorectal cancer cells by regulating the PI3K/Akt/mTOR signaling pathway, and this finding provides a new theoretical basis for targeted therapy of colorectal cancer.

Human beta defensin 3 knockdown inhibits the proliferation and migration of airway smooth muscle cells through regulating the PI3K/AKT signaling pathway.

Asthma, a common pediatric pulmonary disease, significantly affects children's healthy development. This study aimed to investigate the functions of human ß defensin-3 (HBD-3) in asthma progression. For this purpose, blood samples from asthmatic and healthy children were collected. Moreover, the airway smooth muscle cells (ASMCs) were treated with platelet-derived growth factor BB (PDGF-BB) to develop an in vitro asthma model, then evaluated cell viability and migration via CCK-8 and transwell assays. The mRNA levels of interferon γ (INF-γ), interleukin 4 (IL-4), interleukin 10 (IL-10), alpha-smooth muscle actin (α-SMA), HBD-3, and the protein levels of phosphatidylinositol 3-kinase (PI3K) along with protein kinase B (AKT) were detected. Similarly, the N6-methyladenosine (m6A) content in the ASMCs and m6A levels of HBD-3 were also measured. Results indicated an upregulated HBD-3 in the asthmatic children. The ASMCs were found to be stimulated by PDGF-BB, in addition to the promotion of cell viability and migration. The INF-γ, IL-4, and α-SMA levels were reduced, while IL-10 was elevated in PDGF-BB-stimulated ASMCs. Silencing HBD-3 in PDGF-BB stimulated ASMCs was found to exert the opposite effect by inhibiting cell viability and migration, enhancing the levels of INF-γ, IL-4, and α-SMA, while the IL-10 levels were found to decline. PDGF-BB stimulation of ASMCs resulted in activation of the PI3K/AKT signaling pathway, which was blocked post HBD-3 silencing, while the role of si-hBD in PDGF-BB stimulated ASMCs was neutralized post-treatment with IGF-1. Finally, it was found that METTL3 overexpression prominently upregulated the m6A levels of HBD-3 and decreased the mRNA expression and stability of HBD-3 in the PDGF-BB-stimulated ASMCs. The study concluded that METTL3-mediated HBD-3 participates in the progression of asthma through the PI3K/AKT signaling pathway.

Molecular Targeting of the Phosphoinositide-3-Protein Kinase (PI3K) Pathway across Various Cancers.

The dysregulation of the phosphatidylinositol-3-kinase (PI3K) pathway can lead to uncontrolled cellular growth and tumorigenesis. Targeting PI3K and its downstream substrates has been shown to be effective in preclinical studies and phase III trials with the approval of several PI3K pathway inhibitors by the Food and Drug Administration (FDA) over the past decade. However, the limited clinical efficacy of these inhibitors, intolerable toxicities, and acquired resistances limit the clinical application of PI3K inhibitors. This review discusses the PI3K signaling pathway, alterations in the PI3K pathway causing carcinogenesis, current and novel PI3K pathway inhibitors, adverse effects, resistance mechanisms, challenging issues, and future directions of PI3K pathway inhibitors.

GATOR1 Mutations Impair PI3 Kinase-Dependent Growth Factor Signaling Regulation of mTORC1.

GATOR1 (GAP Activity TOward Rag 1) is an evolutionarily conserved GTPase-activating protein complex that controls the activity of mTORC1 (mammalian Target Of Rapamycin Complex 1) in response to amino acid availability in cells. Genetic mutations in the GATOR1 subunits, NPRL2 (nitrogen permease regulator-like 2), NPRL3 (nitrogen permease regulator-like 3), and DEPDC5 (DEP domain containing 5), have been associated with epilepsy in humans; however, the specific effects of these mutations on GATOR1 function and mTORC1 regulation are not well understood. Herein, we report that epilepsy-linked mutations in the NPRL2 subunit of GATOR1, NPRL2-L105P, -T110S, and -D214H, increase basal mTORC1 signal transduction in cells. Notably, we show that NPRL2-L105P is a loss-of-function mutation that disrupts protein interactions with NPRL3 and DEPDC5, impairing GATOR1 complex assembly and resulting in high mTORC1 activity even under conditions of amino acid deprivation. Furthermore, our studies reveal that the GATOR1 complex is necessary for the rapid and robust inhibition of mTORC1 in response to growth factor withdrawal or pharmacological inhibition of phosphatidylinositol-3 kinase (PI3K). In the absence of the GATOR1 complex, cells are refractory to PI3K-dependent inhibition of mTORC1, permitting sustained translation and restricting the nuclear localization of TFEB, a transcription factor regulated by mTORC1. Collectively, our results show that epilepsy-linked mutations in NPRL2 can block GATOR1 complex assembly and restrict the appropriate regulation of mTORC1 by canonical PI3K-dependent growth factor signaling in the presence or absence of amino acids.

AAV-mediated VEGFA overexpression promotes angiogenesis and recovery of locomotor function following spinal cord injury via PI3K/Akt signaling.

Spinal cord injury (SCI) is a disorder of the central nervous system resulting from various factors such as trauma, inflammation, tumors, and other etiologies. This condition leads to impairment in motor, sensory, and autonomic functions below the level of injury. Limitations of current therapeutic approaches prompt an investigation into therapeutic angiogenesis through persistent local expression of proangiogenic factors. Here, we investigated whether overexpression of adeno-associated virus (AAV)-mediated vascular endothelial growth factor A (VEGFA) in mouse SCI promoted locomotor function recovery, and whether the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway was mechanistically involved. Three weeks before SCI, AAV-VEGFA was injected at the T10 level to induce VEGFA overexpression. Neurofunctional, histological, and biochemical assessments were done to determine tissue damage and/or recovery of neuromuscular and behavioral impairments. Daily injections of the PI3K/Akt pathway inhibitor LY294002 were made to assess a possible mechanism. AAV-VEGFA overexpression dramatically improved locomotor function and ameliorated pathological injury caused by SCI. Improved motor-evoked potentials in hindlimbs and more spinal CD31-positive microvessels were observed in AAV-VEGFA-overexpressing mice. LY294002 reduced PI3K and Akt phosphorylation levels and attenuated AAV-VEGFA-related improvements. In conclusion, sustained local AAV-mediated VEGFA overexpression in spinal cord can significantly promote angiogenesis and ameliorate locomotor impairment after SCI in a contusion mouse model through activation of the PI3K/Akt signaling pathway.

Hydromorphone hydrochloride preconditioning combined with postconditioning attenuates myocardial ischemia/reperfusion injury in rats by improving mitochondrial function and activating the PI3K/Akt signaling pathway.

Thrombolytic therapy or percutaneous coronary intervention for myocardial infarction often cause myocardial ischemia/reperfusion injury (MIRI) and poor prognosis of patients. This study aimed to explore the protective effect and potential mechanism of hydromorphone hydrochloride (HH) on MIRI. Fifty Sprague-Dawley male rats were randomly divided into Sham group, I/R group, HH-pre group, HH-post group, and HH-pre + post group. Except Sham group, MIRI models were established by ligating and relaxing the left anterior descending coronary artery, followed by tail vein injection of HH (0.3 µmol/L) 10 min before ligation (HH-pre group), 10 min after reperfusion (HH-post group), and twice at the above two time points (HH-pre + post group). After intervention, the cardiac function of rats was evaluated by echocardiography, and the levels of myocardial injury markers, oxidative stress indicators, and mitochondrial function indicators were detected. Next, the myocardial infarction area was evaluated by 2,3,5-triphenyltetrazolium chloride staining, mitochondrial biogenesis, and phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt) signaling pathway by western blot. Compared with the I/R group, HH intervention improved cardiac function, decreased myocardial infarction area, reduced serum myocardial injury markers, alleviated oxidative stress, improved mitochondrial function, up-regulated mitochondrial biogenesis, and activated PI3K/Akt signaling pathway. Moreover, the HH-pre + post group was superior to the HH-pre and HH-post groups in the above aspects. Collectively, HH had protective effect on MIRI rats, and HH preconditioning combined with postconditioning showed optimal efficacy. Such efficacy may be achieved by promoting mitochondrial biogenesis to improve mitochondrial function and reduce oxidative stress, and activating the PI3K/Akt signaling pathway.

Targeting PI3K/AKT/mTOR and MAPK Signaling Pathways in Gastric Cancer.

Gastric cancer (GC) is the fourth leading cause of death worldwide, with more than 1 million cases diagnosed every year. Helicobacter pylori represents the main risk factor, being responsible for 78% of the cases. Increased amounts of salt, pickled food, red meat, alcohol, smoked food, and refined sugars negatively affect the stomach wall, contributing to GC development. Several gene mutations, including PIK3CA, TP53, ARID1A, CDH1, Ras, Raf, and ERBB3 are encountered in GC pathogenesis, leading to phosphatidylinositol 3-kinase (PI3K) protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-PI3K/AKT/mTOR-and mitogen-activated protein kinase (MAPK) signaling pathway activation and promoting tumoral activity. Helicobacter pylori, growth factors, cytokines, hormones, and oxidative stress also activate both pathways, enhancing GC development. In clinical trials, promising results have come from monoclonal antibodies such as trastuzumab and ramucirumab. Dual inhibitors targeting the PI3K/AKT/mTOR and MAPK signaling pathways were used in vitro studies, also with promising results. The main aim of this review is to present GC incidence and risk factors and the dysregulations of the two protein kinase complexes together with their specific inhibitors.

CD133-Dependent Activation of Phosphoinositide 3-Kinase /AKT/Mammalian Target of Rapamycin Signaling in Melanoma Progression and Drug Resistance.

Melanoma frequently harbors genetic alterations in key molecules leading to the aberrant activation of PI3K and its downstream pathways. Although the role of PI3K/AKT/mTOR in melanoma progression and drug resistance is well documented, targeting the PI3K/AKT/mTOR pathway showed less efficiency in clinical trials than might have been expected, since the suppression of the PI3K/mTOR signaling pathway-induced feedback loops is mostly associated with the activation of compensatory pathways such as MAPK/MEK/ERK. Consequently, the development of intrinsic and acquired resistance can occur. As a solid tumor, melanoma is notorious for its heterogeneity. This can be expressed in the form of genetically divergent subpopulations including a small fraction of cancer stem-like cells (CSCs) and non-cancer stem cells (non-CSCs) that make the most of the tumor mass. Like other CSCs, melanoma stem-like cells (MSCs) are characterized by their unique cell surface proteins/stemness markers and aberrant signaling pathways. In addition to its function as a robust marker for stemness properties, CD133 is crucial for the maintenance of stemness properties and drug resistance. Herein, the role of CD133-dependent activation of PI3K/mTOR in the regulation of melanoma progression, drug resistance, and recurrence is reviewed.