PI3K Inhibitor Research Articles

Oncostatin M promotes epithelial barrier dysfunction in patients with eosinophilic chronic rhinosinusitis with nasal polyps

ABSTRACT Background Oncostatin M (OSM) may be involved in the promotion of mucosal epithelial barrier dysfunction in patients with eosinophilic chronic rhinosinusitis with nasal polyps (Eos CRSwNP) by inducing matrix metalloproteinase (MMP) −1 and −7. The aim was to evaluate the roles and mechanisms of action of OSM on MMP-1 and −7 synthesis from nasal epithelial cells (NECs). Methods OSM, OSM receptor (OSMR), MMP-1 and −7 expression was evaluated in nasal mucosa or primary NECs from scrapings by quantitative polymerase chain reaction (qPCR), immunofluorescence and immunohistochemistry. OSM and other cytokines were used to stimulate air-liquid interface (ALI) cultured NECs. qPCR, enzyme-linked immunosorbent assay (ELISA) and immunofluorescence were used to evaluate the expression of OSMR, MMP-1, −7 and occludin in NECs. Results Elevated levels of OSMRβ, MMP-1 and −7 were found in the tissues and scraped NECs of Eos CRSwNP in comparison to them obtained from the inferior turbinate (IT) and control subjects. The levels of OSM and OSMRβ mRNA in tissues were positively correlated with the levels of MMP-1 and −7. OSM stimulation of NECs increased the expression of MMP-1 and −7, and the responses were suppressed by a STAT3 inhibitor, and a PI3K inhibitor respectively. In parallel studies, we found that stimulation with OSM disrupted the localization of occludin, a tight junction protein in NECs. The response was suppressed by a pan-MMP inhibitor. Conclusion OSM induces the synthesis and release of MMP-1 and −7 in NECs. Furthermore, MMP-1 and −7 promote mucosal epithelial barrier dysfunction in patients with Eos CRSwNP.

Soft Corals-derived Dihydrosinularin Attenuates Neuronal Apoptosis in 6-hydroxydopamine-induced Cell Model of Parkinson's Disease by Regulating the PI3K Pathway.

Parkinson's disease (PD) is an irreversible, progressive disorder that profoundly impacts both motor and non-motor functions, thereby significantly diminishing the individual's quality of life. Dihydrosinularin (DHS), a natural bioactive molecule derived from soft corals, exhibits low cytotoxicity and anti-inflammatory properties. However, the therapeutic effects of DHS on neurotoxins and PD are currently unknown. This study investigated whether DHS could mitigate 6-hydroxydopamine (6- OHDA)-induced neurotoxicity and explored the role of neuroprotective PI3K downstream signaling pathways, including that of AKT, ERK, JNK, BCL2, and NFκB, in DHS- mediated neuroprotection. We treated the human neuroblastoma cell line, SH-SY5Y, with the neurotoxin 6-OHDA to establish a cellular model of PD. Meanwhile, we assessed the anti-apoptotic and neuroprotective properties of DHS through cell viability, apoptosis, and immunostaining assays. Furthermore, we utilized the PI3K inhibitor LY294002 to validate the therapeutic target of DHS. Based on the physicochemical properties of DHS, it can be inferred that it has promising oral bioavailability and permeability across the blood-brain barrier (BBB). It was demonstrated that DHS upregulates phosphorylated AKT and ERK while downregulating phosphorylated JNK. Consequently, this enhances the expression of BCL2, which exerts a protective effect on neuronal cells by inhibiting caspase activity and preventing cell apoptosis. The inhibition of PI3K significantly reduced the relative protective activity of DHS in 6-OHDA-induced neurotoxicity, suggesting that the neuroprotective effects of DHS are mediated through the activation of PI3K signaling. By investigating the mechanisms involved in 6-OHDA-induced neurotoxicity, we provided evidence concerning the therapeutic potential of DHS in neuroprotection. Further research into DHS and its mechanisms of action holds promise for developing novel therapeutic strategies for PD.

Nesfatin-1 regulates the phenotype transition of cavernous smooth muscle cells by activating PI3K/AKT/mTOR signaling pathway to improve diabetic erectile dysfunction.

This study aims to explore the impact of Nesfatin-1 on type 2 diabetic erectile dysfunction (T2DMED) and its underlying mechanism in regulating the phenotypic switching of corpus cavernosum smooth muscle cells (CCSMCs). Twenty-four 4-week-old male C57 wild-type mice were randomly assigned to the control group, model group, and Nesfatin-1 treatment group. Monitoring included body weight, blood glucose levels, and penile cavernous pressure (ICP). Histochemistry and Western blot analyses were conducted to assess the expressions of α-SMA, OPN, and factors related to the PI3K/AKT/mTOR signaling pathway. CCSMCs were categorized into the control group, high glucose and high oleic acid group (GO group), Nesfatin-1 treatment group (GO+N group), sildenafil positive control group (GO+S group), and PI3K inhibitor group (GO+N+E group). Changes in phenotypic markers, cell morphology, and the PI3K/AKT/mTOR signaling pathway were observed in each group. (1) Nesfatin-1 significantly ameliorated the body size, body weight, blood glucose, glucose tolerance, and insulin resistance in T2DMED mice. (2) Following Nesfatin-1 treatment, the ICP/MSBP ratio and the peak of the ICP curve demonstrated a significant increase. (3) Nesfatin-1 significantly enhanced smooth muscle and reduced collagen fibers in the corpus cavernosum. (4) Nesfatin-1 notably increased α-SMA expression and decreased OPN expression in CCSMCs. (5) Nesfatin-1 elevated PI3K, p-AKT/AKT, and p-mTOR/mTOR levels in penile cavernous tissue. Nesfatin-1 not only effectively improves body weight and blood glucose levels in diabetic mice but also enhances erectile function and regulates the phenotypic switching of corpus cavernosum smooth muscle. The potential mechanism involves Nesfatin-1 activating the PI3K/AKT/mTOR signaling pathway to induce the conversion of CCSMCs to a contractile phenotype.

Construction of tissue engineered cornea with skin-derived corneal endothelial-like cell and mechanism research for the cell differentiation.

Corneal endothelial transplantation accounts for most of corneal transplantation for treating corneal diseases, however severe shortage of corneal donors is the biggest obstacle. In our previous study, we differentiated human skin-derived precursors (SKPs) into corneal endothelial cell (CEC)-like cells with a co-culture system. In this study, we aimed to investigate cell differentiation molecular mechanism and evaluate the function of CEC-like cells by developing tissue-engineered corneas in order to improve cell production efficiency and provide basic research for clinical transformation. We performed transcriptome sequencing of SKPs and CEC-like cells. Further, we focused on the possible enriching pathways, including PI3K/Akt, MAPK/Erk, WNT/β-catenin, and important transcription factors Pitx2 and Foxc1. The PI3K and β-catenin inhibitors were also added to the culture system to observe the differentiation alteration. We developed a graft for a tissue-engineered cornea (TEC) using CEC-like cells and acellular porcine cornea matrix scaffold. The tissue-engineered corneas were transplanted into rabbits via penetrating keratoplasty. The PI3K/Akt, MAPK/Erk, and WNT/β-catenin pathways play important roles during the differentiation of SKPs into CEC-like cells. Crosstalk existed between the PI3K/Akt and MAPK/Erk pathways. The PI3K/Akt and WNT/β-catenin pathways were connected. Pitx2 and Foxc1 were subject to temporal and spatial controls of the WNT/β-catenin pathway. The inhibition of the PI3K/Akt and WNT/β-catenin pathways both prevented cell differentiation. CEC-like cells grew well on the acellular porcine cornea matrix scaffold, and the tissue-engineered corneal graft performed well after transplantation into rabbits. We provide experimental basis for CEC-like cell industrial production and drive the cells to be clinically applied in cellular replacement therapy or alternative graft substitution for treating corneal diseases in the future.

ZDHHC20 Activates AKT Signaling Pathway to Promote Cell Proliferation in Hepatocellular Carcinoma.

Liver cancer is the sixth most common cancer worldwide, and hepatocellular carcinoma (HCC) presents one of the most challenging global health issues. ZDHHC20, a member of the ZDHHC palmitoyltransferase (ZDHHC-PAT) family, is involved in a reversible lipid modification known as palmitoylation, which contributes to the occurrence and progression of various tumors. However, the specific mechanisms underlying the involvement of ZDHHC20 in this process are unclear. The effects of both ZDHHC20 knockdown and overexpression on hepatocellular carcinoma cell proliferation were evaluated using PCR, Western blotting, CCK-8 assay, colony formation assay, cell cycle analysis, apoptosis analysis, and EDU assay. The TCGA-LIHC dataset was analyzed bioinformatically, and the phosphorylation level of PI3K and AKT in SK-Hep1 and Huh7 cells was assessed using Western blotting. Nude mouse subcutaneous xenograft experiments were conducted to evaluate the effects of different treatment conditions on mouse tumor growth. ZDHHC20 knockdown inhibited cell proliferation and promoted apoptosis, while overexpression of ZDHHC20 promoted cell proliferation and inhibited apoptosis. Knockdown of ZDHHC20 also decreased phosphorylation of PI3K and AKT in HCC, whereas overexpression of ZDHHC20 increased phosphorylation of PI3K and AKT. The PI3K-AKT pathway inhibitors, LY294002 and MK2206, effectively inhibited the promotional effects of ZDHHC20 on the proliferation and growth of HCC. High expression of ZDHHC20 promotes the proliferation and tumor growth of HCC by activating the PI3K-AKT signaling pathway. The PI3K inhibitor LY294002 and the AKT inhibitor MK2206 inhibit the promotional effects of ZDHHC20 on the proliferation of HCC and the growth of tumors.

Kukoamine A Activates Akt/GSK-3β Pathway to Repress Oxidative Stress and Inflammation to Alleviate Myocardial Ischemia-reperfusion Injury

Background: Myocardial ischemia-reperfusion injury (MI/RI) is a serious complication after revascularization of myocardial infarction, which causes myocardium damage. Kukoamine A (KuA) can repress oxidative stress and neuronal apoptosis in cerebral ischemia animal models. Objective: In the present study, our objective was to explore the role of KuA in MI/RI and the underlying mechanism of KuA in oxidative stress and inflammation of MI/RI. Methods: H9c2 cells’ cytotoxicity was detected using the lactate dehydrogenase (LDH) assay kit. ROS level was measured by immunofluorescence. Male C57BL/6 mice were used to establish MI/RI mice by ligating the left anterior descending coronary artery (LAD). Results: KuA treatment decreased the apoptosis and the cytotoxicity, increased the viability, and reduced the activities of myocardial infarction markers (CKMB, MYO, and cTnI) in hypoxia/ reoxygenation (H/R)-induced H9c2 cells. KuA reduced the levels of ROS, MDA, and inflammatory factors (IL-6, IL-1β, and TNF-α), and facilitated MMP and SOD levels in H/R-induced H9c2 cells. Besides, KuA activated Akt/GSK-3β axis, which was repressed by PI3K inhibitor LY294002. Moreover, KuA improved survival times, decreased the infarct size of mice, and recovered cardiac function in MI/RI mice. Finally, KuA alleviated MI/RI through Akt/GSK-3β pathway in vivo. Conclusion: Thus, KuA exerts a protective function in MI/RI through the Akt/GSK-3β axis to repress oxidative stress and inflammation.

Combination of cisplatin and ethyl acetate extract of Vernonia amygdalina Delile induces cell cycle arrest and apoptosis on PANC-1 cells via PI3K/mTOR

Context: Vernonia amygdalina Delile (VAD) is known as a potential plant with a wide variety of medicinal properties, including anticancer. Aims: To evaluate the combination effect of VAD extract with cisplatin (CIS) against PANC-1 cells, focusing on cell cycle arrest and apoptosis activities. Methods: This study is an experimental study using PANC-1 cells as objects. The phytochemical compounds were analyzed with LC-MS/MS. The cytotoxic activity of extracts and their combinations was determined using the MTT assay method in the PANC-1 cell line. Apoptosis, cell cycle arrest, and PI3K/mTOR profiles were analyzed with flow cytometry. Immunocytochemistry was used to determine Bcl-2, Cyclin D1, and p53 expression. Results: The phytochemicals found were five compounds with retention times of 8.96, 9.85, 10.52, 12.59, and 10.36. The results of the MTT assay showed that the IC50 values of extract and CIS were 21.83 ± 0.46 µg/mL and 3.02 ± 0.44 µg/mL, respectively. The combination index (CI) value of extract and CIS had a synergistic effect. Combination extract and CIS induced early and late apoptosis, inhibited cell cycle progression on the G1 phase, inhibited Bcl-2 and cyclin D1 expression, induced p53 expression, and inhibited PI3K and mTOR expression. Conclusions: The combination of extract and CIS showed anticancer activity against PANC-1 cells through induction of apoptosis and cell cycle arrest via inhibition of PI3K and mTOR expressions.

Live-cell imaging and CLEM reveal the existence of ACTN4-dependent ruffle-edge lamellipodia acting as a novel mode of cell migration

α-Actinin-4 (ACTN4) expression levels are correlated with the invasive and metastatic potential of cancer cells; however, the underlying mechanism remains unclear. Here, we identified ACTN4-localized ruffle-edge lamellipodia using live-cell imaging and correlative light and electron microscopy (CLEM). BSC-1 cells expressing EGFP-ACTN4 showed that ACTN4 was most abundant in the leading edges of lamellipodia, although it was also present in stress fibers and focal adhesions. ACTN4 localization in lamellipodia was markedly diminished by phosphoinositide 3-kinase inhibition, whereas its localization in stress fibers and focal adhesions remained. Furthermore, overexpression of ACTN4, but not ACTN1, promoted lamellipodial formation. Live-cell analysis demonstrated that ACTN4-enriched lamellipodia are highly dynamic and associated with cell migration. CLEM revealed that ACTN4-enriched lamellipodia exhibit a characteristic morphology of multilayered ruffle-edges that differs from canonical flat lamellipodia. Similar ruffle-edge lamellipodia were observed in A549 and MDA-MB-231 invasive cancer cells. ACTN4 knockdown suppressed the formation of ruffle-edge lamellipodia and cell migration during wound healing in A549 monolayer cultures. Additionally, membrane-type 1 matrix metalloproteinase was observed in the membrane ruffles, suggesting that ruffle-edge lamellipodia have the ability to degrade the extracellular matrix and may contribute to active cell migration/invasion in certain cancer cell types.

Targeted Inhibition of the PI3K/Akt/mTOR Signaling Axis: Potential for Sarcoma Therapy.

Sarcoma is a heterogeneous group of malignancies often resistant to conventional chemotherapy and radiation therapy. The phosphatidylinositol-3-kinase/ protein kinase B /mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway has emerged as a critical cancer target due to its central role in regulating key cellular processes such as cell growth, proliferation, survival, and metabolism. Dysregulation of this pathway has been implicated in the development and progression of bone sarcomas (BS) and soft tissue sarcomas (STS). PI3K/Akt/mTOR inhibitors have shown promising preclinical and clinical activity in various cancers. These agents can inhibit the activation of PI3K, Akt, and mTOR, thereby reducing the downstream signaling events that promote tumor growth and survival. In addition, PI3K/Akt/mTOR inhibitors have been shown to enhance the efficacy of other anticancer therapies, such as chemotherapy and radiation therapy. The different types of PI3K/Akt/mTOR inhibitors vary in their specificity, potency, and side effect profiles and may be effective depending on the specific sarcoma type and stage. The molecular targeting of PI3K/Akt/mToR pathway using drugs, phytochemicals, nanomaterials (NMs), and microbe-derived molecules as Pan-PI3K inhibitors, selective PI3K inhibitors, and dual PI3K/mTOR inhibitors have been delineated. While there are still challenges to be addressed, the preclinical and clinical evidence suggests that these inhibitors may significantly improve patient outcomes. Further research is needed to understand the potential of these inhibitors as sarcoma therapeutics and to continue developing more selective and effective agents to meet the clinical needs of sarcoma patients.

Protective effects of Gumibao recipe on glucocorticoid-included bone microcirculatory endothelial cell injury and the underlying mechanism

ObjectiveTo investigate the protective effects of Gumibao recipe on glucocorticoid-included bone microcirculatory endothelial cell (BMEC) injury, and elucidate the possible underlying mechanism. MethodsBMECs were treated with different concentrations of hydrocortisone at different time points, and the viability as well as migration of BMECs were evaluated; furthermore, the release of LDH, levels of VEGF, PAI-1, t-PA, and the content of NO by BMECs have been evaluated by commercially available kits; moreover, the expressions of eNOS, p-PI3K, p-Akt and p-mTOR in BMECs were examined by WB methods. Next, hydrocortisone treated BMECs were co-treated with Gumibao recipe, and the viability, migration and autophagy of BMECs were evaluated. Results0.2 mg/ml and 0.3 mg/ml hydrocortisone significantly decreased viability and migration ability of BMECs, and also impeded the endothelial function of BMECs by decreasing the levels of VEGF, t-PA, the content of NO, and increasing the level of PAI-1. Gumibao medicated serum markedly increased the viability and migration of BMECs, and also increased the levels of VEGF, t-PA, the content of NO, meanwhile decreased the level of PAI-1 in 0.3 mg/ml hydrocortisone treated BMECs; moreover, glucocorticoids inhibited the autophagy of BMECs, and Gumibao recipe significantly increased the autophagy of BMECs; meanwhile, autophagy inhibitor 3-MA partially blocked the protective effects of Gumibao recipe. Finally, gumibao recipe partially abrogated the inhibitory effects of hydrocortisone on the activation of PI3K/Akt/mTOR singling, and these effects were further counteracted by PI3K and mTOR inhibitor NVP-BEZ235. ConclusionsWe reported for the first time the protective effects of Gumibao recipe on glucocorticoid-included BMECs injury, and the possible underlying mechanism may be regulating the autophagy of BMECs via PI3K/AKT/mTOR signaling pathway.

The efficacy and safety of PI3K and AKT inhibitors for patients with cancer: A systematic review and network meta-analysis

BackgroundInhibiting PI3K/AKT pathway activation may hinder the occurrence and progression of cancer. The aim of this study was to evaluate the efficacy and safety of the PI3K/AKT inhibitors and determine the most appropriate inhibitor for different cancer types. MethodsElectronic databases up to June 2024 were used to examine the efficacy and safety of PI3K inhibitors (alpelisib, copanlisib, duvelisib, and idelalisib) and AKT inhibitors (capivasertib, ipatasertib and MK-2206) for the treatment of cancer. Data was assessed with a random-effect pairwise and network meta-analysis. Randomized controlled trials and retrospective studies were eligible if they compared PI3K or AKT inhibitors with non-PI3K/AKT controls with no restriction. ResultsThe results were based on 34 studies from 34 published articles and 6 online registration trials (6710 patients). According to pairwise meta-analysis, PI3K/AKT inhibitors showed to be highly effective, especially for treating mutant cancers, but had poor safety profiles. According to our network meta-analysis, PI3K/AKT inhibitors, especially the AKT inhibitor capivasertib, are effective for treating solid cancers such as breast cancer (BC). Moreover, PI3K inhibitors, especially idelalisib, were effective for treating hematologic cancers such as chronic lymphocytic leukemia (CLL). ConclusionsThe PI3K/AKT inhibitors are effective in patients with genetic mutations. For solid cancers such as BC, capivasertib was efficacy and safety. For hematological cancers represented by CLL, idelalisib was efficacy and safety. The above studies can be used when recommending appropriate targeted therapies for patients with different cancer types.

Genipin promotes the apoptosis and autophagy of neuroblastoma cells by suppressing the PI3K/AKT/mTOR pathway

This study investigated the underlying function and mechanism of genipin in neuroblastoma (NB). Using flow cytometry analysis and cytotoxicity tests, in vitro studies were conducted to assess the effects of genipin on the SK-N-SH cell line. The mechanism of action of genipin was explored through immunofluorescence staining, Western blotting, and caspase-3 activity assays. In addition, we also created a xenograft tumour model to investigate the effects of genipin in vivo. This research confirmed that genipin suppressed cell viability, induced apoptosis, and promoted autophagy, processes that are likely linked to the inhibition of the PI3K/AKT/mTOR signalling pathway. Autophagy inhibition increases the sensitivity of SK-N-SH cells to genipin. Furthermore, combination treatment with a PI3K inhibitor enhanced the therapeutic efficacy of genipin. These results highlight the potential of genipin as a candidate drug for the treatment of NB.

Cancer Therapy with Quinoxaline Derivatives: Dual Inhibition of Pi3k and Mtor Signaling Pathways

Quinoxaline is a heterocyclic compound with a benzene ring fused to a pyrazine ring. It learned much about his ability to cure many diseases, including cancer. Phosphoinositide 3kinase (PI3K) and the mTOR (mammalian target of rapamycin) are the 3 essential pathways which regulate the growth, survival, and development of cells. Dysregulation of such pathways is often seen in cancer, making them attractive targets for cancer therapy. In particular, several quinoxaline derivatives show promise as two inhibitors of the mTOR/PI3K signalling pathway, which is often dysregulated in cancer along with many other diseases. One such example is PX866, which has shown activity against several cancers in previous studies. In previous studies, another quinoxaline derivative, PKI587, also showed strong inhibitory activity against mTOR and PI3K. PKI587 was researched in several clinical trials for treating many cancer types, which include non-small cell lung as well as breast cancer. Dual inhibitors of mTOR and PI3K, including quinoxaline derivatives, inhibit cell growth and cancer by blocking the signalling of these two important factors. In recent years, quinoxaline derivatives have emerged as potent dual inhibitors of PI3K and mTOR, and in this review, we explore the latest developments in this area.

Mechanistic modeling of cell viability assays with in silico lineage tracing.

Data from cell viability assays, which measure cumulative division and death events in a population and reflect substantial cellular heterogeneity, are widely available. However, interpreting such data with mechanistic computational models is hindered because direct model/data comparison is often muddled. We developed an algorithm that tracks simulated division and death events in mechanistically detailed single-cell lineages to enable such a model/data comparison and suggest causes of cell-cell drug response variability. Using our previously developed model of mammalian single-cell proliferation and death signaling, we simulated drug dose response experiments for four targeted anti-cancer drugs (alpelisib, neratinib, trametinib and palbociclib) and compared them to experimental data. Simulations are consistent with data for strong growth inhibition by trametinib (MEK inhibitor) and overall lack of efficacy for alpelisib (PI-3K inhibitor), but are inconsistent with data for palbociclib (CDK4/6 inhibitor) and neratinib (EGFR inhibitor). Model/data inconsistencies suggest (i) the importance of CDK4/6 for driving the cell cycle may be overestimated, and (ii) that the cellular balance between basal (tonic) and ligand-induced signaling is a critical determinant of receptor inhibitor response. Simulations show subpopulations of rapidly and slowly dividing cells in both control and drug-treated conditions. Variations in mother cells prior to drug treatment all impinging on ERK pathway activity are associated with the rapidly dividing phenotype and trametinib resistance. This work lays a foundation for the application of mechanistic modeling to large-scale cell viability assay datasets and better understanding determinants of cellular heterogeneity in drug response.

Mechanism of Kemeng Fang's Inhibition of Podocyte Apoptosis in Rats with Membranous Nephropathy through the PI3K/AKT Signaling Pathway.

Membranous nephropathy (MN) is a common pathological type of adult nephrotic syndrome. Up to 20% of patients with MN develop end-stage renal disease (ESRD). Podocytes have an important function in maintaining the glomerular filtration barrier and play a crucial role in the occurrence and development of proteinuria and MN. PI3K/AKT signaling pathway is involved in the entire process of podocyte growth, differentiation, and apoptosis. Kemeng Fang (KMF) is a traditional Chinese medicine formula that has been used to delay kidney injury. However, the therapeutic mechanism of KMF in MN is unclear. Here, the MN rat model was established by axillary, inguinal, and tail vein injections of cationized bovine serum albumin (C-BSA), and then KMF and PI3K inhibitor (LY294002) were administered. The data of liver function, kidney function, blood lipid, renal pathology, podocyte function, expression level of PI3K/AKT signaling pathway, and transcriptomics of rats demonstrated that KMF has a protective effect on the podocytes of MN rats by activating the PI3K/AKT signaling pathway, and it can effectively prevent the progression of MN.

Screening of a kinase inhibitor library identified novel targetable kinase pathways in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a highly invasive breast cancer subtype that is challenging to treat due to inherent heterogeneity and absence of estrogen, progesterone, and human epidermal growth factor 2 receptors. Kinase signaling networks drive cancer growth and development, and kinase inhibitors are promising anti-cancer strategies in diverse cancer subtypes. Kinase inhibitor screens are an efficient, valuable means of identifying compounds that suppress cancer cell growth in vitro, facilitating the identification of kinase vulnerabilities to target therapeutically. The Kinase Chemogenomic Set is a well-annotated library of 187 kinase inhibitor compounds that indexes 215 kinases of the 518 in the known human kinome representing various kinase networks and signaling pathways, several of which are understudied. Our screen revealed 14 kinase inhibitor compounds effectively inhibited TNBC cell growth and proliferation. Upon further testing, three compounds, THZ531, THZ1, and PFE-PKIS 29, had the most significant and consistent effects across a range of TNBC cell lines. These cyclin-dependent kinase (CDK)12/CDK13, CDK7, and phosphoinositide 3-kinase inhibitors, respectively, decreased metabolic activity in TNBC cell lines and promote a gene expression profile consistent with the reversal of the epithelial-to-mesenchymal transition, indicating these kinase networks potentially mediate metastatic behavior. These data identified novel kinase targets and kinase signaling pathways that drive metastasis in TNBC.

A Perspective of PI3K/AKT/mTOR Pathway Inhibitors to Overcome Drug-resistance in Breast Cancer Therapy.

The heterogeneous disease, breast cancer (BC), is a frequently detected cancer today, including hormone receptor-positive (HR+), human epidermal growth factor receptor-2-positive (HER2+), and triple-negative (ER-, PR-, HER2-) BC. Advanced endocrine therapies could improve about 85% HR+ BC patient survival. Still, 20% - 30% of cases of endocrine therapy resistance are observed. For all kinds of breast cancer, drug resistance is a common and dangerous phenomenon, comprised of two types: de novo resistance and acquired resistance (prolonged exposure). According to recent works of literature, the PI3K/AKT/mTOR pathway has become an emerging target for overcoming drug resistance in BC therapy due to its close association with tumour growth and resistance from current therapies. Activation of the PI3K/AKT/mTOR pathway was found to promote multidrug resistance by elevating drugs' outflow. The first orally active PI3K inhibitor, Alpelisib (BYL-719) in fulvestrant combination, was approved for treating HR+/ HER2- metastatic BC. Therefore, utilizing PI3K/mTOR/AKT inhibitors in combination with currently available strategies could be an optimistic approach to overcoming drug resistance and resensitizing drug-resistant tumor cells of BC. Here, in this perspective, BC cancer therapies related to drug resistance, the involvement of PI3K/AKT/mTOR pathway in drug resistance and multi-drug resistance, and the role of PI3K/AKT/mTOR inhibitors in getting rid of drug resistance have been illuminated.

From lab to clinic: The discovery and optimization journey of PI3K inhibitors

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.

Immunotherapies targeting the oncogenic fusion gene CLDN18-ARHGAP in gastric cancer

The CLDN18-ARHGAP fusion gene is an oncogenic driver newly discovered in gastric cancer. It was detected in 9% (8/87) of gastric cancer patients in our center. An immunogenic peptide specifically targeting CLDN18-ARHGAP fusion gene was generated to induce neoantigen-reactive T cells, which was proved to have specific and robust anti-tumor capacity both in in vitro coculture models and in vivo xenograft gastric cancer models. Apart from the immunogenic potential, CLDN18-ARHGAP fusion gene was also found to contribute to immune suppression by inducing a regulatory T (Treg) cell-enriched microenvironment. Mechanistically, gastric cancer cells with CLDN18-ARHGAP fusion activate PI3K/AKT-mTOR-FAS signaling, which enhances free fatty acid production of gastric cancer cells to favor the survival of Treg cells. Furthermore, PI3K inhibition could effectively reverse Treg cells upregulation to enhance anti-tumor cytotoxicity of neoantigen-reactive T cells in vitro and reduce tumor growth in the xenograft gastric cancer model. Our study identified the CLDN18-ARHGAP fusion gene as a critical source of immunogenic neoepitopes, a key regulator of the tumor immune microenvironment, and immunotherapeutic applications specific to this oncogenic fusion.

Heme: A link between hemorrhage and retinopathy of prematurity progression

Neovascularization is implicated in the pathology of retinopathy of prematurity (ROP), diabetic retinopathy (DR), and age-related macular degeneration (AMD), which are the leading causes of blindness worldwide. In our work, we analyzed how heme released during hemorrhage affects hypoxic response and neovascularization. Our retrospective clinical analysis demonstrated, that hemorrhage was associated with more severe retinal neovascularization in ROP patients. Our heme-stimulated human retinal pigment epithelial (ARPE-19) cell studies demonstrated increased expression of positive regulators of angiogenesis, including vascular endothelial growth factor-A (VEGFA), a key player of ROP, DR and AMD, and highlighted the activation of the PI3K/AKT/mTOR/VEGFA pathway involved in angiogenesis in response to heme. Furthermore, heme decreased oxidative phosphorylation in the mitochondria, augmented glycolysis, facilitated HIF-1α nuclear translocation, and increased VEGFA/GLUT1/PDK1 expression suggesting HIF-1α-driven hypoxic response in ARPE-19 cells without effecting the metabolism of reactive oxygen species. Inhibitors of HIF-1α, PI3K and suppression of mTOR pathway by clinically promising drug, rapamycin, mitigated heme-provoked cellular response. Our data proved that oxidatively modified forms of hemoglobin can be sources of heme to induce VEGFA during retinal hemorrhage. We propose that hemorrhage is involved in the pathology of ROP, DR, and AMD.