Search

PI3K inhibitors have emerged as promising therapeutic agents due to their critical role in various cellular processes, particularly in cancer, where the PI3K pathway is frequently dysregulated. This review explores the evolutionary path of PI3K inhibitors from laboratory discovery to clinical application. The journey begins with early laboratory investigations into PI3K signaling and inhibitor development, highlighting fundamental discoveries that laid the foundation for subsequent advancements. Optimization strategies, including medicinal chemistry approaches and structural modifications, are scrutinized for their contributions to enhancing inhibitor potency, selectivity, and pharmacokinetic properties. The translation from preclinical studies to clinical trials is examined, emphasizing pivotal trials that evaluated efficacy and safety profiles. Challenges encountered during clinical development are critically assessed. Finally, the review discusses ongoing research directions and prospects for PI3K inhibitors, underscoring these agents' continuous evolution and therapeutic potential., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Prostate cancer (PCa) is an extremely common malignant tumor of the male genitourinary system, originating from the prostate gland epithelium. Male patients are prone to relapse after treatment, which seriously threatens their health. Phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB, also known as Akt) plays an important role in the growth, invasion, and metastasis of PCa. This review aimed to present an overview of the mechanism of action of the PI3K/AKT signaling pathway in PCa and discuss the application prospects of inhibitors of this pathway in treating PCa, providing a theoretical basis and reference for its clinical treatment targets., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

PI3Kδ is a key signal transduction molecule in normal and malignant B cells, as well as in T-regulatory cells, making it a promising target for treatment of hematologic malignancies through both direct killing and anti-tumor immunity regulation. BGB-10188 is a highly selective inhibitor of PI3Kδ, showing more than 3000 folds selectivity over other PI3K isoforms and no significant inhibition across tested kinases. BGB-10188 potently inhibited PI3Kδ with IC 50 s ranging from 1.7-16 nM through various in vitro assays and showed a long-lasting and strong target inhibition in mouse B cells in vivo. BGB-10188 showed significant antitumor effects in human B cell lymphoma xenograft models as single agent or in combination with the BTK inhibitor zanubrutinib. BGB-10188 showed significant Treg inhibition in blood but not in colon, along with less drug accumulation in colon compared with idelalisib, which is an approved PI3Kdelta inhibitor with high incidence of gastrointestinal side effects in clinic. In summary, BGB-10188 is a novel PI3Kδ inhibitor with high selectivity, potency and improved safety profile shown in preclinical studies, which is showing the potential as a best-in-class PI3Kδ inhibitor., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The Neuroblastoma RAS (NRAS) oncogene homologue plays crucial roles in diverse cellular processes such as cell proliferation, survival, and differentiation. Several strategies have been developed to inhibit NRAS or its downstream effectors; however, there is no effective drug available to treat NRAS-driven cancers and thus new approaches are needed to be established. The mRNA sequence expressing NRAS containing several guanine(G)-rich regions may form quadruplex structures (G4s) and regulate NRAS translation. Therefore, targeting NRAS mRNA G4s to repress NRAS expression at translational level with ligands may be a feasible strategy against NRAS-driven cancers but it is underexplored. We reported herein a NRAS mRNA G4-targeting ligand, B3C, specifically localized in cytoplasm in HeLa cells. It effectively downregulates NRAS proteins, reactivates the DNA damage response (DDR), causes cell cycle arrest in G 2 /M phase, and induces apoptosis and senescence. Moreover, combination therapy with NARS mRNA G4-targeting ligands and clinical PI3K inhibitors for cancer cells inhibition treatment is unexplored, and we demonstrated that B3C combining with PI3Ki (pictilisib (GDC-0941)) showed potent antiproliferation activity against HeLa cells (IC 50  = 1.03 μM (combined with 10 μM PI3Ki) and 0.42 μM (combined with 20 μM PI3Ki)) and exhibited strong synergistic effects in inhibiting cell proliferation. This study provides new insights into drug discovery against RAS-driven cancers using this conceptually new combination therapy strategy., Competing Interests: Declaration of competing interest Authors declare that they do not have any financial or commercial interest regarding this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: Alpelisib plus fulvestrant demonstrated a significant progression-free survival benefit versus fulvestrant in patients with PIK3CA-mutated HR+ /HER2- advanced breast cancer (ABC) (SOLAR-1). Hyperglycemia, an on-target adverse effect of PI3Kα inhibition, can lead to dose modifications, potentially impacting alpelisib efficacy. We report data from preclinical models and two clinical trials (SOLAR-1 and BYLieve) on Sodium glucose cotransporter 2 inhibitor (SGLT2i) use to improve PI3Kα inhibitor-associated hyperglycemia., Methods: Healthy Brown Norway (BN), mild diabetic Zucker diabetic fatty (ZDF), and Rat1-myr-p110α/HBRX3077 tumor-bearing nude rats treated with alpelisib were analyzed for glucose and insulin control with metformin and dapagliflozin (SGLT2i) and alpelisib efficacy. Hyperglycemia adverse events (AEs) were compared between patients receiving SGLT2i with alpelisib (n = 19) and a propensity score-matched cohort not receiving SGLT2i (n = 74) in both trials., Results: Dapagliflozin and metformin in BN and ZDF rats treated with alpelisib normalized blood glucose and reduced insulin levels. No signs of ketosis or drug-drug interaction were observed when metformin and dapagliflozin was administered with alpelisib. Alpelisib antitumor efficacy was maintained when used with dapagliflozin in tumor-bearing rats. Compared with a matched set of patients without SGLT2i, patients receiving SGLT2i had 4.9 and 6.4 times lower rates of grade ≥ 3 hyperglycemia AEs and hyperglycemia AEs resulting in alpelisib dose adjustments, interruptions, or withdrawals, respectively, and a relative reduction in risk of experiencing these AEs (70.6% and 35.7%)., Conclusion: These data suggest adding an SGLT2i can effectively manage hyperglycemia, resulting in fewer alpelisib dose modifications and discontinuations in patients with PIK3CA-mutated HR+ /HER2- ABC (SOLAR-1: NCT02437318; BYLieve: NCT03056755)., (© 2024. The Author(s).)

The PI3K class I is composed of four PI3K isoforms that serve as regulatory enzymes governing cellular metabolism, proliferation, and survival. The hyperactivation of PI3Kα is observed in various types of cancer and is linked to poor prognosis. Unfortunately, the development inhibitors selectively targeting one of the isoforms remains challenging, with only few agents in clinical use. The main difficulty arises from the high conservation among residues at the ATP-binding pocket across isoforms, which also serves as target pocket for inhibitors. In this work, molecular dynamics and quantum calculations were performed to investigate the molecular features guiding the binding of selective inhibitors, alpelisib and GDC-0326, into the ATP-binding pocket of PI3Kα. While molecular dynamics allowed crystallographic coordinates to relax, the interaction eergy between each amino acid residues and inhibitors was obtained by combining the Molecular Fractionation with Conjugated Caps scheme with Density Functional Theory calculations. In addition, the atomic charge of ligands in the bound and unbound (free) was calculated. Results indicated that the most relevant residues for the binding of alpelisib are Ile932, Glu859, Val851, Val850, Tyr836, Met922, Ile800, and Ile848, while the most important residues for the binding of GDC-0326 are Ile848, Ile800, Ile932, Gln859, Glu849, and Met922. In addition, residues Trp780, Ile800, Tyr836, Ile848, Gln859 Val850, Val851, Ile932 and Met922 are common hotspots for both inhibitors. Overall, the results from this work contribute to improving the understanding of the molecular mechanisms controlling selectivity and highlight important interactions to be considered during the rational design of new agents.Communicated by Ramaswamy H. Sarma.

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma, and it is highly aggressive and heterogeneous. Targeted therapy is still the main treatment method used in clinic due to its lower risk of side effects and personalized medication. Excessive activation of PI3Kδ in DLBCL leads to abnormal activation of the PI3K/Akt pathway, promoting the occurrence and development of DLBCL. The side effects of existing PI3Kδ inhibitors limit their clinical application. The discovery of PI3Kδ inhibitors with novel structures and minimal side effects is urgently needed. This study constructed a PI3Kδ inhibitor screening model to screen natural product libraries. Revealing the mechanism of natural product therapy for DLBCL through network pharmacology, kinase assays, and molecular dynamics. The results of molecular docking indicated that Silibinin had a high docking score and a good binding mode with PI3Kδ. The results of network pharmacology indicated that Silibinin could exert therapeutic effects on DLBCL by inhibiting PI3Kδ activity and affecting the PI3K/Akt pathway. The kinase assays indicated that Silibinin concentration dependently inhibited the activity of PI3Kδ. The results of molecular dynamics indicated that Silibinin could stably bind to PI3Kδ. Silibinin was a structurally novel 3,5,7-trihydroxychroman-4-one PI3Kδ inhibitor, providing valuable information for the subsequent discovery of PI3Kδ inhibitors.

Background: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory condition. Given patients with COPD continue to experience exacerbations despite the availability of effective therapies, anti-inflammatory treatments targeting novel pathways are needed. Kinases, notably the phosphoinositide 3-kinases (PI3K), are thought to be involved in chronic airway inflammation, with this pathway proposed as a critical regulator of inflammation and oxidative stress response in COPD. CHF6523 is an inhaled PI3Kδ inhibitor that has shown positive preclinical results. This manuscript reports the results of a study of CHF6523 in patients with stable COPD (chronic bronchitis phenotype), and who had evidence of type-2 inflammation., Methods: This randomised, double-blind, placebo-controlled, two-way crossover study comprised two 28-day treatment periods separated by a 28-day washout. Patients (N = 44) inhaled CHF6523 in one period, and placebo in the other, both twice daily. The primary objective was to assess the safety and tolerability of CHF6523; the secondary objective was to assess CHF6523 pharmacokinetics. Exploratory endpoints included target engagement (the relative reduction in phosphatidylinositol (3,4,5)-trisphosphate [PIP 3 ]), pharmacodynamic evaluations such as airflow obstruction, and hyperinflation, and to identify biomarker(s) of drug response using proteomics and transcriptomics., Results: CHF6523 plasma pharmacokinetics were characterised by an early maximum concentration (C max ), reached 15 and 10 min after dosing on Days 1 and 28, respectively, followed by a rapid decline. Systemic exposure on Day 28 showed limited accumulation, with ratios < 1.6 for C max and area under the curve from 0 to 12 h post-dose, and with steady state achieved on Day 20. Target engagement was confirmed by a significant 29.7% reduction from baseline in induced sputum PIP 3 (29.5% reduction vs. placebo; adjusted ratio 0.705 [0.580, 0.856]; p = 0.001), but this did not translate into an anti-inflammatory pharmacodynamic effect, as assessed through measures including biomarkers and multi-omics. Additionally, although CHF6523 was generally well-tolerated, 95.2% of patients reported cough as an adverse event, most mild to moderate and resolving within one-hour post-dose., Conclusions: These data, together with those from other PI3K inhibitors, suggest that PI3Kδ is not a suitable pathway for the management of COPD, as the achieved target engagement did not translate into any pharmacodynamic anti-inflammatory effect., Trial Registration: ClinicalTrials.gov (NCT04032535); posted 23rd July 2019., (© 2024. The Author(s).)

Background: We aimed to investigate the effect and potential mechanism of enhancing Neuregulin1 (NRG1)/v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 4 (ErbB4) expression on the differentiation of induced pluripotent stem cells (iPSCs) into cardiomyocytes., Methods: We utilized CRISPR-CAS9 technology to knock in ErbB4 and obtained a single-cell clone IPSN-AAVS1-CMV-ErbB4 (iPSCs-ErbB4). Subsequently, we induced the differentiation of iPSCs into cardiomyocytes and quantified the number of beating embryoid bodies. Furthermore, quantitative real-time PCR assessed the expression of cardiomyocyte markers, including ANP (atrial natriuretic peptide), Nkx2.5 (NK2 transcription factor related locus 5), and GATA4 (GATA binding protein 4). On the 14th day of differentiation, we observed the α-MHC (α-myosin heavy chain)-positive area using immunofluorescent staining and conducted western blotting to detect the expression of cTnT (cardiac troponin) protein and PI3K/Akt signaling pathway-related proteins. Additionally, we intervened the iPSCs-ErbB4 + NRG1 group with the PI3K/Akt inhibitor LY294002 and observed alterations in the expression of cardiomyocyte differentiation-related genes., Results: The number of beating embryoid bodies increased after promoting the expression of NRG1/ErbB4 compared to the iPSCs control group. Cardiomyocyte markers ANP, Nkx2.5, and GATA4 significantly increased on day 14 of differentiation, and the positive area of α-MHC was three times that of the iPSCs control group. Moreover, there was a marked increase in cTnT protein expression. However, there was no significant difference in cardiomyocyte differentiation between the iPSCs-ErbB4 group and the iPSCs control group. Akt phosphorylation was significantly increased in the iPSCs-ErbB4 + NRG1 group. LY294002 significantly reversed the enhancing effect of NRG1/ErbB4 overexpression on Akt phosphorylation as well as the increase in α-MHC and cTnT expression., Conclusions: In conclusion, promoting the expression of NRG1/ErbB4 induced the differentiation of iPSC into cardiomyocytes, possibly through modulation of the PI3K/Akt signaling pathway., (© 2024. The Author(s).)

Aberrant activation or mutation of the EGFR-PI3K-Akt-mTOR signaling pathway has been implicated in a wide range of human cancers, especially non-small-cell lung cancer (NSCLC). Thus, dual inhibition of EGFR and PI3K has been investigated as a promising strategy to address acquired drug resistance resulting from the use of tyrosine kinase inhibitors. A series of dual EGFR/PI3Kα inhibitors was synthesized using pharmacophore hybridization of the third-generation EGFR inhibitor olmutinib and the PI3Kα selective inhibitor TAK-117. The optimal compound 30k showed potent kinase inhibitory activities with IC 50 values of 3.6 and 30.0 nM against EGFR L858R/T790M and PI3Kα, respectively. Compound 30k exhibited a significant antiproliferative effect in NCI-H1975 cells with a higher selectivity profile than olmutinib. The potential antitumor mechanism, molecular binding modes, and in vitro metabolic stability of compound 30k were also clarified., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The combination of gemcitabine, PI3K-Akt pathway inhibitors, and radiation in human glioma cell lines shows potential to enhance radiation sensitivity in aggressive brain tumors. Inhibiting the overactive PI3K-Akt pathway may increase tumor vulnerability to treatment. However, variability in responses among different glioma cell lines highlights the need for personalized approaches. Future research should focus on identifying biomarkers to tailor treatment for individual patients. Additionally, addressing safety concerns and the challenges of translating preclinical findings into clinical practice is crucial. Further studies should explore the therapy's molecular mechanisms and evaluate its clinical potential., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway is a frequently dysregulated pathway in human cancer, and PI3Kα is one of the most frequently mutated kinases in human cancer. A selective PI3Kα inhibitor may provide the opportunity to spare patients the side effects associated with broader inhibition of the class I PI3K family. Here, we describe our efforts to discover a novel series of selective PI3Kα inhibitors using structure-based drug design and molecular docking to inform the design of 6 H -benzo[ c ]chromen inhibitors. XJTU-L453 ( 21 ) was identified with PI3Kα inhibitory potency and unique selectivity over other PI3K isoforms and all other kinases tested. Further evaluation of pharmacokinetic properties and in vivo efficacy led to the identification of the preclinical potential of XJTU-L453 ( 21 ).

PI3Kγ and PI3Kδ plays critical roles in exerting immunosuppression by targeting regulatory T cells and myeloid cells. Dual inhibition of PI3Kγ and PI3Kδ has emerged as a novel therapeutic strategy for cancer immunotherapy. We herein report a series of pyrazolopyridine derivatives with distinct scaffolds as potent and selective dual inhibitors of PI3Kγ and PI3Kδ. Among them, 20e ( IHMT-PI3K-315 ) displays an IC 50 value of 4.0 and 9.1 nM against PI3Kγ and PI3Kδ respectively in biochemical assays. Meanwhile, it potently inhibits PI3Kγ and PI3Kδ-mediated phosphorylation of AKT S473 with EC 50 values of 0.028 and 0.013 μM in cellular assays. In addition, 20e exhibits a favorable selectivity profile in protein kinases at 1 μM. In bone marrow-derived macrophages (BMDM), 20e can repolarize the M2 phenotype to the M1 phenotype. In vivo, 20e demonstrates acceptable pharmacokinetic properties and suppresses tumor growth in a MC38 syngeneic mouse model.

Systemic sclerosis (SSc), also known as scleroderma, is an autoimmune-driven connective tissue disorder that results in fibrosis of the skin and internal organs such as the lung. Fibroblasts are known as the main effector cells involved in the progression of SSc through the induction of extracellular matrix (ECM) proteins and myofibroblast differentiation. Here, we demonstrate that 4'-(cyclopropylmethyl)-N2-4-pyridinyl-[4,5'-bipyrimidine]-2,2'-diamine (PIK-III), known as class III phosphatidylinositol 3-kinase (PIK3C3/VPS34) inhibitor, exerts potent antifibrotic effects in human dermal fibroblasts (HDFs) by attenuating transforming growth factor-beta 1 (TGF-β1)-induced ECM expression, cell contraction and myofibroblast differentiation. Unexpectedly, neither genetic silencing of PIK3C3 nor other PIK3C3 inhibitors (e.g., SAR405 and Autophinib) were able to mimic PIK-III-mediated antifibrotic effect in dermal fibroblasts, suggesting that PIK-III inhibits fibroblast activation through another signaling pathway. We identified that PIK-III effectively inhibits p38 activation in TGF-β1-stimulated dermal fibroblasts. Finally, PIK-III administration significantly attenuated dermal and lung fibrosis in bleomycin-injured mice., Competing Interests: The authors have declared that no competing interests exist”., (Copyright: © 2024 Sanchez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

In this study, seven isoniazid-hydrazone derivatives (3a-g) were synthesized and their structures elucidated by chromatographic techniques, and then the antiproliferative effects of these compounds on various cancer cells were tested. The advanced anticancer mechanism of the most potent compound was then investigated. Antiproliferative activities of the synthesized compounds were evaluated on human breast cancer MCF-7, lung cancer A-549, colon cancer HT-29, and non-cancerous mouse fibroblast 3T3-L1 cell lines by XTT assay. Flow cytometry analysis were carried out to determine cell cycle distribution, apoptosis, mitochondrial membrane potential, multi-caspase activity, and expression of PI3K/AKT signaling pathway. The XTT results showed that all the title molecules displayed cytotoxic activity at varying strengths in different dose ranges, and among them, the strongest cytotoxic effect and high selectivity were exerted by 3d against MCF-7 cells with the IC 50 value of 11.35 µM and selectivity index of 8.65. Flow cytometry results revealed that compound 3d induced apoptosis through mitochondrial membrane disruption and multi-caspase activation in MCF-7 cells. It also inhibited the cell proliferation via inhibition of expression of PI3K/AKT and arrested the cell cycle at G0/G1 phase. In conclusion, all these data disclosed that among the synthesized compounds, 3d is notable for in vivo anticancer studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Among cases of breast cancer, estrogen receptor-positive (ER +), PIK3CA-mutant, HER2- advanced breast cancer stands as a particularly complex clinical indication where approximately 40% of ER + /HER2- breast carcinomas present mutations in the PIK3CA gene. A significant hurdle in treating ER + breast cancer lies in surmounting the challenges of endocrine resistance. In the clinical setting, a multifaceted approach is essential for this indication, one that not only explores the effectiveness of individual treatments but also delves into the potential gains in therapeutic outcome from combination therapies., Methods: In the current study, longitudinal tumor growth inhibition (TGI) models were developed to characterize tumor response over time in postmenopausal women with ER + /HER2- advanced or metastatic breast cancer undergoing treatment with fulvestrant alone or in combination with the PI3K inhibitor, taselisib. Impact of clinically relevant covariates on TGI metrics was assessed to identify patient subsets most likely to benefit from treatment with fulvestrant monotherapy or combination with taselisib., Results: Tumor growth rate constant (K g ) was found to increase with increasing baseline tumor size and in the absence of baseline endocrine sensitivity. Further, K g decreased in the absence of baseline liver metastases both in fulvestrant monotherapy and combination therapy with taselisib. Overall, additive/potentially synergistic anti-tumor effects were observed in patients treated with the taselisib-fulvestrant combination., Conclusion: These results have important implications for understanding the therapeutic impact of combination treatment approaches and individualized responses to these treatments. Finally, this work, emphasizes the importance of model informed drug development for targeted cancer therapy., Clinical Trial Registration: NCT02340221 Registered January 16, 2015, NCT01296555 Registered February 14, 2011., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cancer remains a significant global health challenge, and despite remarkable advancements in therapeutic strategies, poor tolerability of drugs (causing dose reduction/interruptions) and/or the emergence of drug resistance are major obstacles to successful treatment outcomes. Metastatic renal cell carcinoma (mRCC) accounts for 2% of global cancer diagnoses and deaths. Despite the initial success of targeted therapies in mRCC, challenges remain to overcome drug resistance that limits the long-term efficacy of these treatments. Our analysis aim was to develop a semi-mechanistic longitudinal exposure-tumor growth inhibition model for patients with mRCC to characterize and compare everolimus (mTORC1) and apitolisib's (dual PI3K/mTORC1/2) ability to inhibit tumor growth, and quantitate each drug's efficacy decay caused by emergence of tumor resistance over time. Model-estimated on-treatment tumor growth rate constant was 1.7-fold higher for apitolisib compared to everolimus. Estimated half-life for loss of treatment effect over time for everolimus was 16.1 weeks compared to 7.72 weeks for apitolisib, suggesting a faster rate of tumor re-growth for apitolisib patients likely due to the emergence of resistance. Goodness-of-fit plots including visual predictive check indicated a good model fit and the model was able to capture individual tumor size-time profiles. Based on our knowledge, this is the first clinical report to quantitatively assess everolimus (mTORC1) and apitolisib (PI3K/mTORC1/2) efficacy decay in patients with mRCC. These results highlight the difference in overall efficacy of 2 drugs due to the quantified efficacy decay caused by emergence of resistance, and emphasize the importance of model-informed drug development for targeted cancer therapy., (© 2024 The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Since dysregulation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway is associated with the pathogenesis of cancer, inflammation, and autoimmunity, PI3K has emerged as an attractive target for drug development. Although copanlisib is the first pan-PI3K inhibitor to be approved for clinical use, the precise mechanism by which it acts on PI3K has not been fully elucidated. To reveal the binding mechanisms and structure-activity relationship between PI3K and copanlisib, a comprehensive modeling approach that combines 3D-quantitative structure-activity relationship (3D-QSAR), pharmacophore model, and molecular dynamics (MD) simulation was utilized. Initially, the structure-activity relationship of copanlisib and its derivatives were explored by constructing a 3D-QSAR. Then, the key chemical characteristics were identified by building common feature pharmacophore models. Finally, MD simulations were performed to elucidate the important interactions between copanlisib and different PI3K subtypes, and highlight the key residues for tight-binding inhibitors. The present study uncovered the principal mechanism of copanlisib's action on PI3K at the theoretical level, and these findings might provide guidance for the rational design of pan-PI3K inhibitors.Communicated by Ramaswamy H. Sarma.

Lysosomal degradation pathways coordinate the clearance of superfluous and damaged cellular components. Compromised lysosomal degradation is a hallmark of many degenerative diseases, including lysosomal storage diseases (LSDs), which are caused by loss-of-function mutations within both alleles of a lysosomal hydrolase, leading to lysosomal substrate accumulation. Gaucher's disease, characterized by <15% of normal glucocerebrosidase function, is the most common LSD and is a prominent risk factor for developing Parkinson's disease. Here, we show that either of two structurally distinct small molecules that modulate PIKfyve activity, identified in a high-throughput cellular lipid droplet clearance screen, can improve glucocerebrosidase function in Gaucher patient-derived fibroblasts through an MiT/TFE transcription factor that promotes lysosomal gene translation. An integrated stress response (ISR) antagonist used in combination with a PIKfyve modulator further improves cellular glucocerebrosidase activity, likely because ISR signaling appears to also be slightly activated by treatment by either small molecule at the higher doses employed. This strategy of combining a PIKfyve modulator with an ISR inhibitor improves mutant lysosomal hydrolase function in cellular models of additional LSD., Competing Interests: Competing interests statement:W.C.H., L.A.M., D.R., and J.W.K. are inventors on the patent “PIKfyve Modulators for Treatment of Lysosomal Storage Diseases,” U.S. Ser. No. 63/675,391.

Purpose: Estrogen receptor (ER) alpha signaling is a known driver of ER-positive (ER+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer. Combining endocrine therapy (ET) such as fulvestrant with CDK4/6, mTOR, or PI3K inhibitors has become a central strategy in the treatment of ER+ advanced breast cancer. However, suboptimal ER inhibition and resistance resulting from the ESR1 mutation dictates that new therapies are needed., Experimental Design: A medicinal chemistry campaign identified vepdegestrant (ARV-471), a selective, orally bioavailable, and potent small molecule PROteolysis-TArgeting Chimera (PROTAC) degrader of ER. We used biochemical and intracellular target engagement assays to demonstrate the mechanism of action of vepdegestrant, and ESR1 wild-type (WT) and mutant ER+ preclinical breast cancer models to demonstrate ER degradation-mediated tumor growth inhibition (TGI)., Results: Vepdegestrant induced ≥90% degradation of wild-type and mutant ER, inhibited ER-dependent breast cancer cell line proliferation in vitro, and achieved substantial TGI (87%-123%) in MCF7 orthotopic xenograft models, better than those of the ET agent fulvestrant (31%-80% TGI). In the hormone independent (HI) mutant ER Y537S patient-derived xenograft (PDX) breast cancer model ST941/HI, vepdegestrant achieved tumor regression and was similarly efficacious in the ST941/HI/PBR palbociclib-resistant model (102% TGI). Vepdegestrant-induced robust tumor regressions in combination with each of the CDK4/6 inhibitors palbociclib, abemaciclib, and ribociclib; the mTOR inhibitor everolimus; and the PI3K inhibitors alpelisib and inavolisib., Conclusions: Vepdegestrant achieved greater ER degradation in vivo compared with fulvestrant, which correlated with improved TGI, suggesting vepdegestrant could be a more effective backbone ET for patients with ER+/HER2- breast cancer., (©2024 The Authors; Published by the American Association for Cancer Research.)

The Phosphatidylinositol-3-kinase (PI3K) family is well-known to comprise three classes of intracellular enzymes. Class I PI3Ks primarily function in signaling by responding to cell surface receptor stimulation, while class II and III are more involved in membrane transport. Under normal physiological conditions, the PI3K signaling network orchestrates cell growth, division, migration and survival. Aberrant activation of the PI3K signaling pathway disrupts cellular activity and metabolism, often marking the onset of cancer. Currently, the Food and Drug Administration (FDA) has approved the clinical use of five class I PI3K inhibitors. These small-molecule inhibitors, which exhibit varying selectivity for different class I PI3K family members, are primarily used in the treatment of breast cancer and hematologic malignancies. Therefore, the development of novel class I PI3K inhibitors has been a prominent research focus in the field of oncology, aiming to enhance potential therapeutic selectivity and effectiveness. In this review, we summarize the specific structures of PI3Ks and their functional roles in cancer progression. Additionally, we critically evaluate small molecule inhibitors that target class I PI3K, with a particular focus on their clinical applications in cancer treatment. Moreover, we aim to analyze therapeutic approaches for different types of cancers marked by aberrant PI3K activation and to identify potential molecular targets amenable to intervention with small-molecule inhibitors. Ultimately, we propose future directions for the development of therapeutic strategies that optimize cancer treatment outcomes by modulating the PI3K family., (© 2024. The Author(s).)

Relapsed or refractory diffuse large B cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) patients still faced with poor survival, representing an unmet clinical need. In-depth research into the disease's pathogenesis and the development of targeted treatment strategies are urgently needed. Here, we conducted a comprehensive bioinformatic analysis of gene mutation and expression using data from our center and public databases. Cell cycle-related genes especially for CDKN2A/B-CDK4/6/CCND1 machinery altered frequently in DLBCL and MCL. Clinically, high CDK4 and CDK6 expression were correlated with poor prognosis of DLBCL and MCL patients. Furthermore, we also validated the pharmacological efficacy of CDK4/6 inhibitor palbociclib and its synergy effect with PI3K inhibitor idelalisib utilizing in vitro cell lines and in vivo cell-derived xenograft (CDX) and patient-derived xenograft (PDX) mouse models. Our results provided sufficient pre-clinical evidence to support the potential combination of palbociclib and idelalisib for DLBCL and MCL patients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: Sangbaipi decoction (SBPD), a traditional Chinese medicine (TCM) prescription, has been widely used to treat acute exacerbation of chronic obstructive pulmonary disease (AECOPD), while the underlying pharmacological mechanism remains unclear due to the complexity of composition., Methods: A TCM-active ingredient-drug target network of SBPD was constructed utilizing the TCM-Systems-Pharmacology database. AECOPD-relevant proteins were gathered from Gene Cards and the Online-Mendelian-Inheritance-in-Man database. Protein-protein interaction, GO and KEGG enrichment analyses of the targets from the intersection of SBPD and AECOPD targets were performed to identify the core signaling pathway, followed by molecular docking verification of its interaction with active ingredients. The network pharmacology results were checked using in-vivo experiments. To induce AECOPD, rats were exposure to combined tobacco smoke and lipopolysaccharide (LPS). Then rats underwent gavage with stigmasterol (SM) after successful modeling. The involvement of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling was investigated using its inhibitor, LY294002. Lung function and histopathology were examined. The levels of inflammatory cytokines in the lung and serum were assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blot and/or Enzyme-linked immunosorbent assay (ELISA)., Results: SM was recognized as an active ingredient of SBPD and stably bound to Akt1. SM improved lung function and histological abnormalities, concomitant with suppressed PI3K/Akt signaling, downregulated lung and serum Interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) levels and serum transforming growth factor-β (TGF-β) levels and upregulated lung and serum Interleukin 10 (IL-10) levels in AECOPD rats. In AECOPD rats, LY294002 restored lung function, and it also improved lung histological abnormalities and inflammation, which was found to be potentiated by SM., Conclusion: SM targets PI3K/Akt signaling to reduce lung injury and inflammation in AECOPD rats., Competing Interests: The authors declare no conflicts of interest in this work., (© 2024 He et al.)

The intricate interplay between immune and stromal cells within the tumour microenvironment (TME) significantly influences tumour progression. Myeloid cells, including tumour-associated macrophages (TAMs), neutrophils (TANs), and myeloid-derived suppressor cells (MDSCs), contribute to immune suppression in the TME (Nakamura and Smyth in Cell Mol Immunol 17(1):1-12 (2020). https://doi.org/10.1038/s41423-019-0306-1 ; DeNardo and Ruffell in Nat Rev Immunol 19(6):369-382 (2019). https://doi.org/10.1038/s41577-019-0127-6 ). This poses a significant challenge for novel immunotherapeutics that rely on host immunity to exert their effect. This systematic review explores the preclinical evidence surrounding the inhibition of phosphoinositide 3-kinase gamma (PI3Kγ) as a strategy to reverse myeloid-driven immune suppression in solid tumours. EMBASE, MEDLINE, and PubMed databases were searched on 6 October 2022 using keyword and subject heading terms to capture relevant studies. The studies, focusing on PI3Kγ inhibition in animal models, were subjected to predefined inclusion and exclusion criteria. Extracted data included tumour growth kinetics, survival endpoints, and immunological responses which were meta-analysed. PRISMA and MOOSE guidelines were followed. A total of 36 studies covering 73 animal models were included in the review and meta-analysis. Tumour models covered breast, colorectal, lung, skin, pancreas, brain, liver, prostate, head and neck, soft tissue, gastric, and oral cancer. The predominant PI3Kγ inhibitors were IPI-549 and TG100-115, demonstrating favourable specificity for the gamma isoform. Combination therapies, often involving chemotherapy, radiotherapy, immune checkpoint inhibitors, biological agents, or vaccines, were explored in 81% of studies. Analysis of tumour growth kinetics revealed a statistically significant though heterogeneous response to PI3Kγ monotherapy, whereas the tumour growth in combination treated groups were more consistently reduced. Survival analysis showed a pronounced increase in median overall survival with combination therapy. This systematic review provides a comprehensive analysis of preclinical studies investigating PI3Kγ inhibition in myeloid-driven tumour immune suppression. The identified studies underscore the potential of PI3Kγ inhibition in reshaping the TME by modulating myeloid cell functions. The combination of PI3Kγ inhibition with other therapeutic modalities demonstrated enhanced antitumour effects, suggesting a synergistic approach to overcome immune suppression. These findings support the potential of PI3Kγ-targeted therapies, particularly in combination regimens, as a promising avenue for future clinical exploration in diverse solid tumour types., (© 2024. The Author(s).)

Phosphoinositide 3-kinase alpha (PI3Kα) is one of the most frequently dysregulated kinases known for their pivotal role in many oncogenic diseases. While the side effects linked to existing drugs against PI3Kα-induced cancers provide an avenue for further research, the significant structural conservation among PI3Ks makes it extremely difficult to develop new isoform-selective PI3Kα inhibitors. Embracing this challenge, we herein designed a hybrid protocol by integrating machine learning (ML) with in silico drug-designing strategies. A deep learning classification model was developed and trained on the physicochemical descriptors data of known PI3Kα inhibitors and used as a screening filter for a database of small molecules. This approach led us to the prediction of 662 compounds showcasing appropriate features to be considered as PI3Kα inhibitors. Subsequently, a multiphase molecular docking was applied to further characterize the predicted hits in terms of their binding affinities and binding modes in the targeted cavity of the PI3Kα. As a result, a total of 12 compounds were identified whereas the best poses highlighted the efficiency of these ligands in maintaining interactions with the crucial residues of the protein to be targeted for the inhibition of associated activity. Notably, potential activity of compound 12 in counteracting PI3Kα function was found in a previous in vitro study. Following the drug-likeness and pharmacokinetic characterizations, six compounds (compounds 1, 2, 3, 6, 7, and 11) with suitable ADME-T profiles and promising bioavailability were selected. The mechanistic studies in dynamic mode further endorsed the potential of identified hits in blocking the ATP-binding site of the receptor with higher binding affinities than the native inhibitor, alpelisib (BYL-719), particularly the compounds 1, 2, and 11. These outcomes support the reliability of the developed classification model and the devised computational strategy for identifying new isoform-selective drug candidates for PI3Kα inhibition., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Despite tremendous progress in precision oncology, adaptive resistance mechanisms limit the long-term effectiveness of molecularly targeted agents. Here we evaluated the pharmacological profile of MTX-531 that was computationally designed to selectively target two key resistance drivers, epidermal growth factor receptor and phosphatidylinositol 3-OH kinase (PI3K). MTX-531 exhibits low-nanomolar potency against both targets with a high degree of specificity predicted by cocrystal structural analyses. MTX-531 monotherapy uniformly resulted in tumor regressions of squamous head and neck patient-derived xenograft (PDX) models. The combination of MTX-531 with mitogen-activated protein kinase kinase or KRAS-G12C inhibitors led to durable regressions of BRAF-mutant or KRAS-mutant colorectal cancer PDX models, resulting in striking increases in median survival. MTX-531 is exceptionally well tolerated in mice and uniquely does not lead to the hyperglycemia commonly seen with PI3K inhibitors. Here, we show that MTX-531 acts as a weak agonist of peroxisome proliferator-activated receptor-γ, an attribute that likely mitigates hyperglycemia induced by PI3K inhibition. This unique feature of MTX-531 confers a favorable therapeutic index not typically seen with PI3K inhibitors., (© 2024. The Author(s).)

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 100 ns 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 = -18.80 kcal/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., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Phosphatidylinositol 3-kinase (PI3-K) signalling pathway is a crucial path in cancer for cell survival and thus represents an intriguing target for new paediatric anti-cancer drugs. However, the unique clinical toxicities of targeting this pathway (resulting in hyperglycaemia) difficulties combining with chemotherapy, rarity of mutations in childhood tumours and concomitant mutations have resulted in major barriers to clinical translation of these inhibitors in treating both adults and children. Mutations in PIK3CA predict response to PI3-K inhibitors in adult cancers. The same mutations occur in children as in adults, but they are significantly less frequent in paediatrics. In children, high-grade gliomas, especially diffuse midline gliomas (DMG), have the highest incidence of PIK3CA mutations. New mutation-specific PI3-K inhibitors reduce toxicity from on-target PI3-Kα wild-type activity. The mTOR inhibitor everolimus is approved for subependymal giant cell astrocytomas. In paediatric cancers, mTOR inhibitors have been predominantly evaluated by academia, without an overall strategy, in empiric, mutation-agnostic clinical trials with very low response rates to monotherapy. Therefore, future trials of single agent or combination strategies of mTOR inhibitors in childhood cancer should be supported by very strong biological rationale and preclinical data. Further preclinical evaluation of glycogen synthase kinase-3 beta inhibitors is required. Similarly, even where there is an AKT mutation (∼0.1 %), the role of AKT inhibitors in paediatric cancers remains unclear. Patient advocates strongly urged analysing and conserving data from every child participating in a clinical trial. A priority is to evaluate mutation-specific, central nervous system-penetrant PI3-K inhibitors in children with DMG in a rational biological combination. The choice of combination, should be based on the genomic landscape e.g. PTEN loss and resistance mechanisms supported by preclinical data. However, in view of the very rare populations involved, innovative regulatory approaches are needed to generate data for an indication., Competing Interests: Declaration of Competing Interest RB is an employee of Genentech, A Member of the Roche Group, South San Francisco, CA USA. JC is an employee of Bayer Healthcare Pharmaceuticals, Whippany, NJ, USA. SGD has received consulting fees for advisory board participation from Amgen, Bayer, InhibRx, and Jazz and travel funding from Loxo, Roche, and Salarius. JF is an employee of Kazia Therapeutics. IG an employee of Celcuity. HK is an employee of Loxo Oncology at Lilly. DL is an employee of Merck Sharp & Dohme. AM is an employee of Actuate. MEM has receiving consulting fees for advisory board participation from Ymabs Therapeutics, Recordati and travel funding from Bayer. KN has received consulting fees for advisory board participation from Y-mAbs, EUSA Pharma and Bayer, fees for teaching from Bayer and serving on a data monitoring committee from Lilly. ADJP has consulted for Lilly, Norgine and Developmental Therapeutics Consortium Limited and been an advisor for Amgen. All remaining authors have declared no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The phosphoinositide 3-kinase (PI3K) is involved in regulation of multiple intracellular processes. Although the inhibitory analysis is generally employed for validating a physiological role of PI3K, increasing body of evidence suggests that PI3K inhibitors can exhibit PI3K-unrelated activity as well. Here we studied Ca 2+ signaling initiated by aminergic agonists in a variety of different cells and analyzed effects of the PI3K inhibitor PI828 on cell responsiveness. It turned out that PI828 inhibited Ca 2+ transients elicited by acetylcholine (ACh), histamine, and serotonin, but did not affect Ca 2+ responses to norepinephrine and ATP. Another PI3K inhibitor wortmannin negligibly affected Ca 2+ signaling initiated by any one of the tested agonists. Using the genetically encoded PIP 3 sensor PH(Akt)-Venus, we confirmed that both PI828 and wortmannin effectively inhibited PI3K and ascertained that this kinase negligibly contributed to ACh transduction. These findings suggested that PI828 inhibited Ca 2+ responses to aminergic agonists tested, involving an unknown cellular mechanism unrelated to the PI3K inhibition. Complementary physiological experiments provided evidence that PI828 could inhibit Ca 2+ signals induced by certain agonists, by acting extracellularly, presumably, through their surface receptors. For the muscarinic M3 receptor, this possibility was verified with molecular docking and molecular dynamics. As demonstrated with these tools, wortmannin could be bound in the extracellular vestibule at the muscarinic M3 receptor but this did not preclude binding of ACh to the M3 receptor followed by its activation. In contrast, PI828 could sterically block the passage of ACh into the allosteric site, preventing activation of the muscarinic M3 receptor., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cancer is a complex and multifaceted group of diseases with a high mortality rate characterized by uncontrolled proliferation of abnormal cells. Dysregulation of normal signalling pathways in cancer contributes to the different hallmarks of this disease. The signalling pathway of which phosphatidylinositol 3-kinase (PI3K) is a part is not an exception. In fact, dysregulated activation of PI3K signalling pathways can result in unbridled cellular proliferation and enhanced cell survival, thereby fostering the onset and advancement of cancer. Therefore, there is substantial interest in developing targeted therapies specifically aimed at inhibiting the PI3K enzyme and its associated pathways. Also, the therapeutic interest on pyrazoles and indazoles has been growing due to their various medicinal properties, namely, anticancer activity. Derivatives of these compounds have been studied as PI3K inhibitors, and they showed promising results. There are already some PI3K inhibitors approved by Food and Drug Administration (FDA), such as Idelalisib (Zydelig®) and Alpelisib (Piqray®). In this context, this review aims to address the importance of PI3K in cellular processes and its role in cancer. Additionally, it aims to report a comprehensive literature review of PI3K inhibitors, containing the pyrazole and indazole scaffolds, published in the last fifteen years, focusing on structure-activity relationship aspects, thus providing important insights for the design of novel and more effective PI3K inhibitors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Aim: Neuroblastoma (NB) is, in spite of current intensive therapy with severe side effects, still not cured so new therapies are needed. Recently, we showed combining phosphoinositide 3-kinase (PI3K) (BYL719), fibroblast growth factor receptor (FGFR) (JNJ-42756493) and cyclin-dependent kinase 4/6 (CDK4/6) (PD-0332991) inhibitors, in vitro in NB cell lines grown as monolayers had synergistic effects. However, there were variations depending on the combinations used and the targeted NB cell lines. To obtain further information and to mimic more natural circumstances, we investigated the effects of single and combined administrations of the above inhibitors in spheroid NB-cultures., Material and Methods: Spheroid cultures of NB cell lines SK-N-AS, SK-N-BE(2)-C, SK-N-FI and SK-N-SH were established and treated with single and combined administrations of BYL719, JNJ-42756493, and PD-0332991 and followed for growth, viability, proliferation, cytotoxicity and migration., Key Findings: Single inhibitor administrations gave dose dependent responses with regard to growth and viability and their combinations were efficient and resulted in a range of additive and synergistic effects. The responses to individual drugs and their various combinations were predominantly alike regardless of whether the cells were cultivated in monolayer or D spheroid NB models. However, in general, slightly higher drug concentrations were necessary in spheroidcultures., Significance: This study provides pre-clinical evidence that single PI3K, FGFR, and CDK4/6, inhibitors exhibit promising anti-NB activity and when combined lower doses of the drugs could be also used in spheroid NB-cultures, supporting the pursuit of further in vitro and in vivo studies in preparation for future potential clinical use., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Metastatic recurrence is still a major challenge in breast cancer treatment. Patients with triple negative breast cancer (TNBC) develop early recurrence and relapse more frequently. Due to the lack of specific therapeutic targets, new targeted therapies for TNBC are urgently needed. Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway is one of the active pathways involved in chemoresistance and survival of TNBC, being considered as a potential target for TNBC treatment. Our present study identified ticagrelor, an anti-platelet drug, as a pan-PI3K inhibitor with potent inhibitory activity against four isoforms of class I PI3K. At doses normally used in clinic, ticagrelor showed weak cytotoxicity against a panel of breast cancer cells, but significantly inhibited the migration, invasion and the actin cytoskeleton organization of human TNBC MDA-MB-231 and SUM-159PT cells. Mechanistically, ticagrelor effectively inhibited PI3K downstream mTOR complex 1 (mTORC1) and mTORC2 signaling by targeting PI3K and decreased the protein expression of epithelial-mesenchymal transition (EMT) markers. In vivo, ticagrelor significantly suppressed tumor cells lung metastasis in 4T1 tumor bearing BALB/c mice model and experimental lung metastasis model which was established by tail vein injection of GFP-labeled MDA-MB-231 cells. The above data demonstrated that ticagrelor can inhibit the migration and invasion of TNBC both in vitro and in vivo by targeting PI3K, suggesting that ticagrelor, a pan-PI3K inhibitor, might represent a promising therapeutic agent for the treatment of metastatic TNBC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Dysregulated transcription due to disruption in histone lysine methylation dynamics is an established contributor to tumorigenesis 1,2 . However, whether analogous pathologic epigenetic mechanisms act directly on the ribosome to advance oncogenesis is unclear. Here we find that trimethylation of the core ribosomal protein L40 (rpL40) at lysine 22 (rpL40K22me3) by the lysine methyltransferase SMYD5 regulates mRNA translation output to promote malignant progression of gastric adenocarcinoma (GAC) with lethal peritoneal ascites. A biochemical-proteomics strategy identifies the monoubiquitin fusion protein partner rpL40 (ref. 3 ) as the principal physiological substrate of SMYD5 across diverse samples. Inhibiting the SMYD5-rpL40K22me3 axis in GAC cell lines reprogrammes protein synthesis to attenuate oncogenic gene expression signatures. SMYD5 and rpL40K22me3 are upregulated in samples from patients with GAC and negatively correlate with clinical outcomes. SMYD5 ablation in vivo in familial and sporadic mouse models of malignant GAC blocks metastatic disease, including peritoneal carcinomatosis. Suppressing SMYD5 methylation of rpL40 inhibits human cancer cell and patient-derived GAC xenograft growth and renders them hypersensitive to inhibitors of PI3K and mTOR. Finally, combining SMYD5 depletion with PI3K-mTOR inhibition and chimeric antigen receptor T cell administration cures an otherwise lethal in vivo mouse model of aggressive GAC-derived peritoneal carcinomatosis. Together, our work uncovers a ribosome-based epigenetic mechanism that facilitates the evolution of malignant GAC and proposes SMYD5 targeting as part of a potential combination therapy to treat this cancer., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Phosphoinositide kinases (PIKs) are a type of lipid kinase that acts as an upstream activator of oncogenic signaling. Presently accessible therapeutic compounds have downsides, such as toxicity and dubious efficacy, as well as lengthy treatment durations, which have bred resistance. Here we attempt to screen the Indian Ocean-derived red algal compounds to be used as a promising lead for PI3Kα inhibitor development. Experimental structure of the PI3K alpha Isoform-Specific Inhibitor alpelisib complex-based pharmacophore model was constructed and used as key to mark off the suitable lead compounds from the pool of marine-derived red algal compounds of Indian Ocean. Besides, the study encompasses pharmacophore scaffold screening as well as physicochemical and pharmacokinetic parameter assessment. We employed molecular docking and molecular dynamics simulation to assess the binding type and stability of 21 red algal derivatives. Twelve compounds demonstrated a sustained binding mode within the PI3Kα binding pocket with an optimal protein backbone root-mean-square deviation, also prompted hydrogen bonding throughout the simulations, and also implies that these MNPs have firmly mediated the interaction with prime hinge region residues in the PI3Kα ATP binding pocket. DFT studies revealed that proposed compounds had the greatest occupied molecular orbital electrophilicity index, basicity, and dipole moment, all of which attributed their stability as well as binding affinity at the PI3Kα active site. Our study's findings revealed that CMNPD31054, CMNPD4798, CMNPD27861, CMNPD4799, CMNPD27860, CMNPD9533, CMNPD3732, CMNPD4221, CMNPD31058, CMNPD31052, CMNPD29281, and CMNPD31055 can be used as lead compounds for PI3KΑ isoform inhibitors design., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The results of the SOLAR-1 and CAPItello-291, highlight the benefit of the ɑ-selective phosphoinositide 3-Kinase Pathway inhibitor (PI3Ki) alpelisib and the AKT inhibitor (AKTi) capivasertib in patients with hormone receptor-positive (HR+)/Human Epidermal Growth Factor Receptor 2 (HER2)- negative metastatic breast cancer (mBC) that have PIK3CA/AKT1/PTEN tumour alterations. Although effective, these drugs are associated with significant toxicities, which often limit their use, particularly in frail patients. Following the recent incorporation of these agents into clinical practice, and with many others currently in development, significant challenges have emerged, particularly those regarding biomarkers for patient selection. This review will discuss biomarkers of response and their resistance to PI3K/AKT inhibitors (PI3K/AKTis) in HR+/HER- BC in early and advanced settings to ascertain which populations will most benefit from these drugs. Of the biomarkers that were analysed, such as PIK3CA, AKT, PTEN mutations, insulin levels, 18 F- FDG-PET/TC, only the PIK3CA-mutations (PIK3CA-mut) and the AKT pathway alterations seem to have a predictive value for treatments with alpelisib and capivasertib. However, due to the retrospective and exploratory nature of the study, the data did not provide conclusive results. In addition, the different methods used to detect PIK3CA/AKT1/PTEN alterations underline the fact that the optimal diagnostic companion has yet to be established. We have summarised the clinical data on the approved and discontinued agents targeting this pathway and have assessed the drugs development, successes, and failures. Finally, because of tumour heterogeneity, we emphasise the importance of reassessing the mutational status of PI3KCA in both metastatic tissue and blood at the time of disease progression to better tailor treatment for patients., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships, which may be considered as potential competing interests: GNM: meeting/travel grants from Roche, Bayer, and AstraZeneca (all outside the submitted work). EdA: Financial: Honoraria and/or advisory board from Roche/GNE, Novartis, SeaGen, Zodiac, Libbs, Pierre Fabre, Lilly, Astra-Zeneca, MSD, Gilead Sciences; Travel grants from Roche/GNE and Astra-Zeneca; Research grant to my institution from Roche/GNE, Astra-Zeneca, and GSK/Novartis, Gilead Sciences; Non-financial: ESMO director of Membership 2023–2024 and BSMO President 2023–2026. UdG: Advisory Board: MSD, Bristol Myers Squibb, Janssen, Astellas, Sanofi, Bayer, Pfizer, Ipsen, Novartis, and PharmaMar. Institutional research grants: AstraZeneca, Sanofi, and Roche, (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

In their recent paper published in Nature, Luo et al. 1 investigate the cancer-cell-intrinsic roles of the PI3Kγ complex in leukemia. Their findings pinpoint PI3Kγ inhibition as a possible novel treatment avenue for a subset of acute leukemias., Competing Interests: Declaration of interests H.K. is supported by the EMBO Postdoctoral Fellowship. N.V. reports grants from the NIH/NCI (5K08CA245192), Breast Cancer Alliance, and Gilead; consulting activities for Avenzo Therapeutics, Pfizer, Reactive Biosciences, and Scorpion Therapeutics; travel expenses from Gilead; stock in Reactive Biosciences; and patent US20210189503A1 pending to Memorial Sloan Kettering Cancer Center., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A hit-to-lead campaign pursuing the identification of novel inhalant small-molecule phosphatidylinositol 3-kinase (PI3K) inhibitors for the treatment of inflammatory respiratory diseases is disclosed. A synthetically versatile pyridazin-3(2 H )-one scaffold was designed, and three exit vectors on the core moiety were used to explore chemical diversity and optimize pharmacological and absorption, distribution, metabolism, and excretion (ADME) properties. Desired modulation of PI3Kδ selectivity and cellular potency as well as ADME properties in view of administration by inhalation was achieved. Intratracheal administration of lead compound 26 resulted in a promising pharmacokinetic profile, thus demonstrating that the optimization strategy of in vitro profiles successfully translated to an in vivo setting.

The PI3K/AKT/mTOR pathway plays critical roles in a wide array of biological processes. Phosphatidylinositol 3-kinase gamma (PI3Kγ), a class IB PI3K family member, represents a potential therapeutic opportunity for the treatment of cancer, inflammation, and autoimmunity. In this Perspective, we provide a comprehensive overview of the structure, biological function, and regulation of PI3Kγ. We also focus on the development of PI3Kγ inhibitors over the past decade and emphasize their binding modes, structure-activity relationships, and pharmacological activities. The application of computational technologies and artificial intelligence in the discovery of novel PI3Kγ inhibitors is also introduced. This review aims to provide a timely and updated overview on the strategies for targeting PI3Kγ.

PI3Kα is a lipid kinase that phosphorylates PIP2 and generates PIP3. The hyperactive PI3Kα mutation, H1047R, accounts for about 14% of breast cancer, making it a highly attractive target for drug discovery. Here, we report the cryo-EM structures of PI3Kα H1047R bound to two different allosteric inhibitors QR-7909 and QR-8557 at a global resolution of 2.7 Å and 3.0 Å, respectively. The structures reveal two distinct binding pockets on the opposite sides of the activation loop. Structural and MD simulation analyses show that the allosteric binding of QR-7909 and QR-8557 inhibit PI3Kα H1047R hyper-activity by reducing the fluctuation and mobility of the activation loop. Our work provides a strong rational basis for a further optimization and development of highly selective drug candidates to treat PI3Kα H1047R -driven cancers., Competing Interests: Declaration of interests X.H., K.W., J.H., X.C., Z.W., T.W., B.Y., F.Z., X.W., H.L., Z.X., X.Z, W.Z., and X.R. are employees of Regor Therapeutics Group., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: BMS-1166, a PD-1/PD-L1 inhibitor, inhibits the binding of PD-L1 to PD-1, restores T cell function, and enhances tumor immune response. However, mutations in the tumor suppressor or impaired cellular signaling pathways may also lead to cellular transformation. In this study, the SW480 and SW480R cell lines were used as the model to elucidate the treatment with BMS-1166, BEZ235, and their combination. Methods: MTT and colony-formation assays were used to evaluate cell proliferation. Wound-healing assay was used to assess cell migration. Cell cycle and apoptosis were analyzed by flow cytometry. The phosphorylation level of the key kinases in the PI3K/Akt/mTOR and MAPK pathways, PD-L1, and the protein levels related to the proliferation, migration, and apoptosis were assessed using western blotting. Results: BEZ235 enhanced BMS-1166-mediated cell proliferation and migration inhibition in SW480 and SW480R cells and promoted apoptosis. Interestingly, the downregulation of the negative regulator PTEN raised the PD-L1 level, which was abolished by the inhibition of Akt. BMS-1166 promoted PI3K, Akt, mTOR, and Erk phosphorylation. However, the combination of BEZ235 with BMS-1166 suppressed the expression of PI3K, p-Akt, p-mTOR, and p-Erk in SW480 and SW480R cells compared to BMS-1166 or BEZ235 single treatment by inhibiting the binding of PD1 to PD-L1. Conclusions: PD-1 binds to PD-L1 and activates the PI3K/mTOR and MAPK pathways, which might be the molecular mechanism of acquired resistance of CRC to BMS-1166. The combination of the two drugs inhibited the phosphorylation of PI3K, Akt, and Erk in the PI3K/mTOR and MAPK pathway, i.e., BEZ235 enhanced the BMS-1166 treatment effect by blocking the PI3K/mTOR pathway and interfering with the crosstalk of the MAPK pathway. Therefore, these findings provide a theoretical basis for BMS-1166 combined with BEZ235 in the trial treatment of colorectal cancer., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Colorectal cancer (CRC) is one of the most common tumors of the digestive system worldwide. KRAS mutations limit the use of anti-EGFR antibodies in combination with chemotherapy for the treatment of CRC. Therefore, novel targeted therapies are needed to overcome the KRAS-induced oncogenesis. Recent evidence suggests that inhibition of PI3K led to ferroptosis, a nonapoptotic cell death closely related to KRAS-mutant cells. Here, we showed that a selective PI3Kδ inhibitor TYM-3-98 can suppress the AKT/mTOR signaling and activate the ferroptosis pathway in KRAS-mutant CRC cells in a concentration-dependent manner. This was evidenced by the lipid peroxidation, iron accumulation, and depletion of GSH. Moreover, the overexpression of the sterol regulatory element-binding protein 1 (SREBP1), a downstream transcription factor regulating lipid metabolism, conferred CRC cells greater resistance to ferroptosis induced by TYM-3-98. In addition, the effect of TYM-3-98 was confirmed in a xenograft mouse model, which demonstrated significant tumor suppression without obvious hepatoxicity or renal toxicity. Taken together, our work demonstrated that the induction of ferroptosis contributed to the PI3Kδ inhibitor-induced cell death via the suppression of AKT/mTOR/SREBP1-mediated lipogenesis, thus displaying a promising therapeutic effect of TYM-3-98 in CRC treatment., (© 2024. The Author(s).)

Virulent infectious agents such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and methicillin-resistant Staphylococcus aureus (MRSA) induce tissue damage that recruits neutrophils, monocyte, and macrophages, leading to T cell exhaustion, fibrosis, vascular leak, epithelial cell depletion, and fatal organ damage. Neutrophils, monocytes, and macrophages recruited to pathogen-infected lungs, including SARS-CoV-2-infected lungs, express phosphatidylinositol 3-kinase gamma (PI3Kγ), a signaling protein that coordinates both granulocyte and monocyte trafficking to diseased tissues and immune-suppressive, profibrotic transcription in myeloid cells. PI3Kγ deletion and inhibition with the clinical PI3Kγ inhibitor eganelisib promoted survival in models of infectious diseases, including SARS-CoV-2 and MRSA, by suppressing inflammation, vascular leak, organ damage, and cytokine storm. These results demonstrate essential roles for PI3Kγ in inflammatory lung disease and support the potential use of PI3Kγ inhibitors to suppress inflammation in severe infectious diseases.

YM201636 is the potent PIKfyve inhibitor that is being actively investigated for liver cancer efficacy. In this study, computer simulations and experiments were conducted to investigate the interaction mechanism between YM201636 and the transport protein HSA. Results indicated that YM201636 is stably bound between the subdomains IIA and IIIA of HSA, supported by site marker displacement experiments. YM201636 quenched the endogenous fluorescence of HSA by static quenching since a decrease in quenching constants was observed from 7.74 to 2.39 × 10 4  M -1 . UV-vis and time-resolved fluorescence spectroscopy confirmed the YM201636-HSA complex formation and this binding followed a static mechanism. Thermodynamic parameters ΔG, ΔH, and ΔS obtained negative values suggesting the binding was a spontaneous process driven by Van der Waals interactions and hydrogen binding. Binding constants ranged between 5.71 and 0.33 × 10 4  M -1 , which demonstrated a moderately strong affinity of YM201636 to HSA. CD, synchronous, and 3D fluorescence spectroscopy revealed that YM201636 showed a slight change in secondary structure. The increase of K app and a decrease of PSH with YM201636 addition showed that YM201636 changed the surface hydrophobicity of HSA. The research provides reasonable models helping us further understand the transportation and distribution of YM201636 when it absorbs into the blood circulatory system., (© 2024 John Wiley & Sons Ltd.)

Introduction: As a vital mechanism of survival, lymphopoiesis requires the collaboration of different signaling molecules to orchestrate each step of cell development and maturation. The PI3K pathway is considerably involved in the maturation of lymphatic cells and therefore, its dysregulation can immensely affect human well-being and cause some of the most prevalent malignancies. As a result, studies that investigate this pathway could pave the way for a better understanding of the lymphopoiesis mechanisms, the undesired changes that lead to cancer progression, and how to design drugs to solve this issue., Areas Covered: The present review addresses the aforementioned aspects of the PI3K pathway and helps pave the way for future therapeutic approaches. In order to access the articles, databases such as Medicine Medline/PubMed, Scopus, Google Scholar, and Science Direct were utilized. The search formula was established by identifying main keywords including PI3K/Akt/mTOR pathway, Lymphopoiesis, Lymphoid malignancies, and inhibitors., Expert Opinion: The PI3K pathway is crucial for lymphocyte development and differentiation, making it a potential target for therapeutic intervention in lymphoid cancers. Studies are focused on developing PI3K inhibitors to impede the progression of hematologic malignancies, highlighting the pathway's significance in lymphoma and lymphoid leukemia.

Despite considerable progress in developing vaccines and antivirals to combat COVID-19, the rapid mutations of the SARS-CoV-2 genome have limited the durability and efficacy of the current vaccines and therapeutic interventions. Hence, it necessitates the development of novel therapeutic approaches or repurposing existing drugs that target either viral life cycle, host factors, or both. Here, we report that SRX3177, a potent triple-activity CDK4/6-PI3K-BET inhibitor, blocks replication of the SARS-CoV-2 Omicron variant with IC 50 values at sub-micromolar concentrations without any impact on the cell proliferation of Calu-3 cells at and below its IC 50 concentration. When SRX3177 is combined with EIDD-1931 (active moiety of a small-molecule prodrug Molnupiravir) or MU-UNMC-2 (a SARS-CoV-2 entry inhibitor) at a fixed doses matrix, a synergistic effect was observed, leading to the significant reduction in the dose of the individual compounds to achieve similar inhibition of SARS-CoV-2 replication. Herein, we report that the combination of SRX3177/MPV or SRX3177/UM-UNMC-2 has the potential for further development as a combinational therapy against SARS-CoV-2 and in any future outbreak of beta coronavirus., Competing Interests: Declaration of competing interest D.L.D. has equity interests in SignalRx Pharmaceuticals, Inc., as a shareholder and has patent related to the multi-target inhibitors (patent number WO2020023340A1). All other authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Hepatotoxicity is the main off-target effect of methotrexate (MTX) limiting its effective clinical use. Besides, MDA-MB231 breast cancer cells show chemoresistance, partly via PI3K/AKT pathway. Therefore, we investigated the ameliorative potentials of the PI3K inhibitor, alpelisib (ALP) on MTX-induced hepatotoxicity (in vivo) and the restraining potentials of ALP on MDA-MB231 chemoresistance to MTX (in vitro). Twenty-eight male BALB/c mice were divided into 4 groups. In treatment groups, mice were administered ALP (2.5 and 5 mg/kg) for 5 days and MTX (20 mg/kg) from day 2 till day 5. The results showed that ALP restored hepatic architecture, reduced immune cell infiltration (F4/80, Ly6G and MPO) and repressed the rise in liver enzymes (AST and ALT) induced by MTX. Additionally, ALP rectified the MTX-induced disruption of cellular oxidant status by boosting antioxidant defense systems (HO-1 and GSH) and repressing lipid peroxidation (MDA and 4-HNE). Finally, ALP curbed MTX-induced hepatocyte apoptosis (NF-κB and BAX) and shifted the cytokine milieu away from inflammation (IL-17, IL-22, IL-6 and IL- 10). The results of the in vitro experiments revealed that ALP alone and in combination with MTX, synergistically, reduced cancer cell viability (MTT assay), migration (wound healing assay) and their capacity to establish colonies (colony formation assay) as compared to MTX alone. RT-PCR revealed the antiproliferative (Bcl-2) and proapoptotic (BAX) potentials of ALP and ALP/MTX combination especially after 24 h. In conclusion, targeting PI3K/AKT pathway is a promising strategy in triple negative breast cancer patients by ameliorating hepatotoxicity and restraining chemoresistance to chemotherapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)