Inhibition Of PI3K-Akt Pathway Research Articles

Hsa_circ_0049472 contributed to amyloid-beta peptide-induced neurotoxicity, apoptosis and inflammation via regulating PI3K-AKT signaling pathway by interacting with miR-22–3p/ZNF217 axis

BackgroundCircular RNAs (circRNAs) exhibited important roles in Alzheimer’s disease (AD). Here, we focused on the dysregulation of hsa_circ_0049472 (circ_0049472) and potential functions in SK-N-SH cells with amyloid-beta peptide (Aβ) treatment in AD. MethodsRNA expression was detected by real-time quantitative PCR. Cell viability and proliferation were measured by MTS and Edu assays. Flow cytometry was used for apoptosis detection, and cell inflammation was assessed using enzyme-linked immunosorbent assay. Target interaction was validated by dual-luciferase reporter assay and RNA immunoprecipitation assay. Protein expression and phosphatidylinositol 3-kinase-protein kinase B (PI3K-AKT) pathway were examined by Immunoblotting. ResultsAβ treatment inhibited cell viability and proliferation of SK-N-SH cells, but enhanced apoptosis rate, apoptosis protein levels (Bcl2-associated X protein and cleaved-caspase-3) and inflammatory cytokines (interleukin −6, IL-1β, tumor necrosis factor-α). Then, circ_0049472 expression was shown to be upregulated in response to Aβ stimulation and knockdown of circ_0049472 has ameliorated Aβ-induced cell injury. Circ_0049472 was identified as a sponge for miR-22–3p, and miR-22–3p inhibition reversed the regulation of circ_0049472 knockdown in Aβ-treated cells. Furthermore, ZNF217 acted as a target of miR-22–3p and circ_0049472 could regulate ZNF217 expression via binding to miR-22–3p. Overexpression of miR-22–3p abated Aβ-induced apoptosis and inflammation via downregulating ZNF217. Furthermore, Aβ reduced proteins levels of p-PI3K and p-AKT, and this inhibition of PI3K-AKT pathway was restored by the regulation of circ_0049472/miR-22–3p/ZNF217 axis. ConclusionCirc_0049472 was involved in Aβ-induced neural injury by regulating miR-22–3p/ZNF217 axis to affect PI3K-AKT pathway. This study has discovered an innovative mechanism for AD.

The effect of adipose-derived mesenchymal stem cell transplantation on ovarian mitochondrial dysfunction in letrozole-induced polycystic ovary syndrome in rats: the role of PI3K-AKT signaling pathway

ObjectiveThe present study aimed to elucidate how mesenchymal stem cells (MSCs) application could efficiently attenuate pathological changes of letrozole-induced poly cystic ovary syndrome (PCOS) by modulating mitochondrial dynamic via PI3K-AKT pathway.MethodsThirty-two female rats were randomly divided into four experimental groups: Sham, PCOS, PCOS + MSCs, and PCOS + MSCs + LY294002. The Sham group received 0.5% w/v carboxymethyl cellulose (CMC); the PCOS group received letrozole (1 mg/kg, daily) in 0.5% CMC for 21 days. Animals in the PCOS + MSCs group received 1 × 106 MSCs/rat (i.p,) on the 22th day of the study. In the PCOS + MSCs + LY294002 group, rats received LY294002 (PI3K-AKT inhibitor) 40 min before MSC transplantation. Mitochondrial dynamic gene expression, mitochondrial membrane potential (MMP), citrate synthase (CS) activity, oxidative stress, inflammation, ovarian histological parameters, serum hormone levels, homeostatic model assessment for insulin resistance (HOMA-IR), insulin and glucose concentrations, p-PI3K and p-AKT protein levels were evaluated at the end of the experiment.ResultsPCOS rats showed a significant disruption of mitochondrial dynamics and histological changes, lower MMP, CS, ovary super oxide dismutase (SOD) and estrogen level. They also had a notable rise in insulin and glucose concentrations, HOMA-IR, testosterone level, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels, ovarian malondialdehyde (MDA) content as well as a notable decrease in p-PI3K and p-AKT protein levels compared to the Sham group. In the PCOS + MSCs group, the transplantation of MSCs could improve the above parameters. Administration of LY294002 (PI3K-AKT pathway inhibitor) deteriorated mitochondrial dynamic markers, oxidative stress status, inflammation markers, hormonal levels, glucose, and insulin levels and follicular development compared to the PCOS + MSCs group.ConclusionsThis study demonstrated that the protective effects of MSC transplantation in regulating mitochondrial dynamics, promoting mitochondrial biogenesis, competing with redox status and inflammation response were mainly mediated through the PI3K-AKT pathway in the PCOS model.

Caffeic Acid Dimethyl Ether Ameliorates Excessive Glucose and Lipid-Induced Insulin Secretion Dysfunction in Pancreatic Beta-Cells through the miR-378b–PI3K–AKT Pathway

An important factor in the progression of type 2 diabetes mellitus is the malfunctioning insulin production by β-cells in the pancreas. Caffeic acid dimethyl ether (CADE) reduces resistance to insulin in alcoholic fatty liver disease, but both the therapeutic effects of CADE on excessive glucose and lipid-induced insulin secretion disorders and the underlying mechanisms are unknown. The aim of this research was to (i) explore how CADE impacts insulin production issues caused by a surplus of glucose and lipids β-cells and (ii) elucidate the underlying mechanism. The results of our research demonstrated that insulin production was reduced in the pancreas of mice given a high-fat -diet and streptozotocin, as well as in human 1.1B4 pancreatic β-cells treated with high -glucose and high -fat, with increased activity of miR-378b and decreased expression levels of p110α, p-AKT1/2, insulin receptor, p-FoxO1, and PDX-1. However, treatment with CADE ameliorated the insulin secretion impairment by decreasing the miR-378b level and reversing the inhibitory effects on the aforementioned factors. Overexpression of miR-378b exacerbated the insulin secretion disorder and inhibited the PI3K-AKT signaling pathway, whereas miR-378b deficiency relieved the insulin secretion disorder, activating the PI3K-AKT pathway. In addition, CADE ameliorated the impairment of insulin secretion and reversed the miR-378b overexpression-induced PI3K-AKT pathway inhibition. In conclusion, our study demonstrates that CADE ameliorated insulin secretion dysfunction induced by excess lipid and glucose in β-cells by downregulating miR-378b expression, thus promoting PI3K-AKT activation.

Whole-transcriptome defines novel glucose metabolic subtypes in colorectal cancer.

Colorectal cancer (CRC) is the most prevalent malignancy of the digestive system. Glucose metabolism plays a crucial role in CRC development. However, the heterogeneity of glucose metabolic patterns in CRC is not well characterized. Here, we classified CRC into specific glucose metabolic subtypes and identified the key regulators. 2228 carbohydrate metabolism-related genes were screened out from the GeneCards database, 202 of them were identified as prognosis genes in the TCGA database. Based on the expression patterns of the 202 genes, three metabolic subtypes were obtained by the non-negative matrix factorization clustering method. The C1 subtype had the worst survival outcome and was characterized with higher immune cell infiltration and more activation in extracellular matrix pathways than the other two subtypes. The C2 subtype was the most prevalent in CRC and was characterized by low immune cell infiltration. The C3 subtype had the smallest number of individuals and had a better prognosis, with higher levels of NRF2 and TP53 pathway expression. Secreted frizzled-related protein 2 (SFRP2) and thrombospondin-2 (THBS2) were confirmed as biomarkers for the C1 subtype. Their expression levels were elevated in high glucose condition, while their knockdown inhibited migration and invasion of HCT 116 cells. The analysis of therapeutic potential found that the C1 subtype was more sensitive to immune and PI3K-Akt pathway inhibitors than the other subtypes. To sum up, this study revealed a novel glucose-related CRC subtype, characterized by SFRP2 and THBS2, with poor prognosis but possible therapeutic benefits from immune and targeted therapies.

Trimethylamine N-Oxide Induces Renal Fibrosis Through the PI3K/AKT/SREBP1 Pathway

To investigate the role and mechanism of trimethylamine N-oxide (TMAO), a uremic toxin, in renal fibrosis. A total of 20 male BALB/c mice were randomly and evenly assigned to a Control group and a TMAO group. Mice in the Control group received intraperitoneal injection of normal saline, while mice in the TMAO group received intraperitoneal injection of TMAO (20 mg/[kg·d]). The injection was given once a day for 8 weeks. Histopathology and fibrosis of kidney were observed by H&E staining and Masson staining. Immunohistochemistry was performed to determine the levels of alpha smooth muscle actin (α-SMA), recombinant human fibronectin fragment (Fibronectin), and sterol-regulatory element binding protein 1 (SREBP1). Western blot was performed to determine α-SMA, SREBP1, phosphatidylinositol 3 kinase (PI3K), phospho-phosphatidylinositol 3 kinase (p-PI3K), protein kinase B (PKB, also known as AKT), and phospho-AKT (p-AKT) protein levels. HK2 cells were treated with SREBP1 small interfering RNA (siRNA) and PI3K/AKT inhibitor, respectively, and the reversal of the effects of TMAO was examined. Animal experiments showed that, compared with the Control group, the mice treated with TMAO experienced pathological damage and fibrosis of the kidney tissue and the expression levels of fibrosis markers, α-SMA and Fibronectin, in the kidney were increased (all P<0.05). According to the findings from further investigation, the TMAO-treatment group showed increased expression of SREBP1 and an up-regulation of PI3K phosphorylation ratio and AKT phosphorylation ratio compared with those of the Control group (all P<0.05). Cell experiments produced results similar to those of the animal experiment. After siRNA interference with SREBP1 expression, the expression levels of fibrosis marker proteins decreased (P<0.05). Besides, the high expression of SREBP1 caused by TMAO was inhibited after HK2 cells were incubated with LY294002, a PI3K-AKT pathway inhibitor (P<0.05). TMAO may induce renal fibrosis by promoting the PI3K/AKT/SREBP1 pathway.

Role of Akt/Protein Kinase B in Cancer Metastasis.

Metastasis is a critical step in the process of carcinogenesis and a vast majority of cancer-related mortalities result from metastatic disease that is resistant to current therapies. Cell migration and invasion are the first steps of the metastasis process, which mainly occurs by two important biological mechanisms, i.e., cytoskeletal remodelling and epithelial to mesenchymal transition (EMT). Akt (also known as protein kinase B) is a central signalling molecule of the PI3K-Akt signalling pathway. Aberrant activation of this pathway has been identified in a wide range of cancers. Several studies have revealed that Akt actively engages with the migratory process in motile cells, including metastatic cancer cells. The downstream signalling mechanism of Akt in cell migration depends upon the tumour type, sites, and intracellular localisation of activated Akt. In this review, we focus on the role of Akt in the regulation of two events that control cell migration and invasion in various cancers including head and neck squamous cell carcinoma (HNSCC) and the status of PI3K-Akt pathway inhibitors in clinical trials in metastatic cancers.

TPN10475 alleviates concanavalin A-induced autoimmune hepatitis by limiting T cell development and function through inhibition of PI3K-AKT pathway

Autoimmune hepatitis (AIH) is an inflammatory liver disease in which the autoimmune system instigates an attack on the liver, causing inflammation and liver injury, and its incidence has increased worldwide in recent years. The mouse model of acute hepatitis established by concanavalin A (Con A) is a typical and recognized mouse model for the study of T-cell-dependent liver injury. In this study, we aimed to investigate whether the artemisinin derivative TPN10475 could alleviate AIH and its possible mechanisms. TPN10475 effectively inhibited lymphocyte proliferation and IFN-γ+ T cells production in vitro, alleviated liver injury by decreasing infiltrating inflammatory T cells producing IFN-γ in the liver and peripheral immune tissues, and demonstrated that TPN10475 weakened the activation and function of T cells by inhibiting PI3K-AKT signaling pathway. These results suggested that TPN10475 may be a potential drug for the treatment of AIH, and the inhibition of PI3K-AKT signaling pathway may provide new ideas for the study of the pathogenesis of AIH.

#3939 EFFECTIVENESS OF IMATINIB FOR MCTO NEPHROPATHY

Abstract Background and Aims MAFB is a podocyte-specific transcription factor. Point mutations in the MAFB transactivation domain in humans result in multicentric carpometacarpal-tarsal osteolysis (MCTO). MCTO patients show focal segmental glomerulosclerosis (FSGS) due to podocyte damage, known as MCTO nephropathy. Effective treatment for MCTO has not been found. Imatinib is a tyrosine kinase inhibitor (TKI), which inhibits PI3K-Akt pathway, and is in long-term use for the treatment of chronic myeloid leukemia. Method In order to develop a new treatment for MCTO, we generated disease model mice using the CRISPR-Cas9 system. These animals have the same genetic mutation as human MCTO patients. Albuminuria was evaluated at 4 weeks of age, and renal histological analysis was performed at 26 weeks of age. In addition, RNA-seq for isolated glomeruli of 10-week-old MCTO mice and wild-type animal was performed for genetic and pathway analysis. Results MCTO mice exhibited growth retardation, and presented albuminuria from 4 weeks of age. Foot process effacement and FSGS-like renal histological changes were shown. Nephropathy symptoms were similar to that of human MCTO patients. Interestingly, the upregulated genes in RNA-seq analysis were a group of receptor genes associated with PI3K-Akt signaling, including lpar1 and csfr1.Transesophageal administration of imatinib, a PI3K-Akt pathway inhibitor, treatment for 5 consecutive weeks decreased albuminuria and ameliorated histological renal damage. RNA-seq of isolated glomeruli of MCTO mice after imatinib treatment showed decreased expression of genes associated with TGFβ-related signaling pathways compared to the non-treated group. Recently, enhanced PI3K-Akt signaling in podocytes has been linked to several renal diseases associated with podocyte injury. In addition, lpar1 inhibition in glomeruli is known to suppress TGFβ. Imatinib suppressed PI3K-Akt signaling, which is enhanced in podocytes of MCTO mice. This may have shown a podocyte-protective effect by suppressing fibrosis-related genes such as TGFβ. Imatinib is classified as a TKI, but frequency of podocyte toxicity is lower than other TKIs. Conclusion The podocyte injury mechanism of MCTO nephropathy is associated with enhanced PI3K-Akt signaling in podocytes. Imatinib inhibits this pathway and suppresses TGFβ. Imatinib may become a therapeutic agent for MCTO nephropathy.

Network Pharmacology and Experimental Validation to Reveal the Anti-Inflammatory Effects of Schefflera Octophylla and Waigan Mixture II Through Inhibition of PI3K-AKT Pathway

Network Pharmacology and Experimental Validation to Reveal the Anti-Inflammatory Effects of Schefflera Octophylla and Waigan Mixture II Through Inhibition of PI3K-AKT Pathway

A cellular senescence-related classifier based on a tumorigenesis- and immune infiltration-guided strategy can predict prognosis, immunotherapy response, and candidate drugs in hepatocellular carcinoma.

Cellular senescence plays an irreplaceable role in tumorigenesis, progression, and tumor microenvironment (TME) remodeling. However, to date, there is limited research delineating the landscape of cellular senescence in hepatocellular carcinoma (HCC), and an improved understanding on the interaction of tumor-associated cellular senescence with HCC prognosis, TME, and response to immunotherapy is warrant. Tumorigenic and immune infiltration-associated senescence genes were determined by weighted gene co-expression network analysis (WGCNA) and the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm, and subsequently, a prognostic scoring model (named TIS) was constructed using multiple survival analysis algorithms to classify the senescence-related subtypes of HCC. Gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) were conducted to identify the distinct hallmark pathways between high- and low-risk subtypes. Additionally, we carried out correlation analyses for TIS and clinical traits, senescence-associated secretory phenotype (SASP), immune infiltration and evasion, immune checkpoint factors, drug response, and immunotherapeutic efficacy. External experimental validation was conducted to delineate the association of CPEP3 (a TIS gene) with HCC phenotypes through assays of proliferation, colony formation, and invasion. A five-gene TIS, composed of NET1, ATP6V0B, MMP1, GTDC1, and CPEB3, was constructed and validated using TCGA and ICGC datasets, respectively, and showed a highly robust and plausible signature for overall survival (OS) prediction of HCC in both training and validation cohorts. Patients in the TIS-high group were accompanied by worse OS, activation of carcinogenetic pathways, infiltration of immunosuppressive cells, exclusion of effector killing cells, overexpression of immunomodulatory genes and SASP, and unsatisfied response to immunotherapy. In response to anticancer drugs, patients in the TIS-high group exhibited enhanced susceptibility to several conventional chemotherapeutic agents (5-fluorouracil, docetaxel, doxorubicin, gemcitabine, and etoposide), as well as several inhibitors of pathways involved in cellular senescence (cell-cycle inhibitors, bromodomain and extraterminal domain family (BET) inhibitors, PI3K-AKT pathway inhibitors, and multikinase inhibitors). Additionally, four putative drugs (palbociclib, JAK3 inhibitor VI, floxuridine, and lestaurtinib) were identified as potential compounds for patients in the TIS-high group. Notably, in vitro functional validation showed that CPEB3 knockdown boosted the phenotypes of proliferation, clonogenicity, and invasion in HCC cells, whereas CPEB3 overexpression attenuated these phenotypes. Our study provides comprehensive clues demonstrating the role of novel TIS in predicting HCC prognosis, immunotherapeutic response, and candidate drugs. This work highlights the significance of tumorigenesis- and immune infiltration-related cellular senescence in cancer therapy.

AKT-mTORC1 reactivation is the dominant resistance driver for PI3Kβ/AKT inhibitors in PTEN-null breast cancer and can be overcome by combining with Mcl-1 inhibitors

The PI3K pathway is commonly activated in breast cancer, with PI3K-AKT pathway inhibitors used clinically. However, mechanisms that limit or enhance the therapeutic effects of PI3K-AKT inhibitors are poorly understood at a genome-wide level. Parallel CRISPR screens in 3 PTEN-null breast cancer cell lines identified genes mediating resistance to capivasertib (AKT inhibitor) and AZD8186 (PI3Kβ inhibitor). The dominant mechanism causing resistance is reactivated PI3K-AKT-mTOR signalling, but not other canonical signalling pathways. Deletion of TSC1/2 conferred resistance to PI3Kβi and AKTi through mTORC1. However, deletion of PIK3R2 and INPPL1 drove specific PI3Kβi resistance through AKT. Conversely deletion of PIK3CA, ERBB2, ERBB3 increased PI3Kβi sensitivity while modulation of RRAGC, LAMTOR1, LAMTOR4 increased AKTi sensitivity. Significantly, we found that Mcl-1 loss enhanced response through rapid apoptosis induction with AKTi and PI3Kβi in both sensitive and drug resistant TSC1/2 null cells. The combination effect was BAK but not BAX dependent. The Mcl-1i + PI3Kβ/AKTi combination was effective across a panel of breast cancer cell lines with PIK3CA and PTEN mutations, and delivered increased anti-tumor benefit in vivo. This study demonstrates that different resistance drivers to PI3Kβi and AKTi converge to reactivate PI3K-AKT or mTOR signalling and combined inhibition of Mcl-1 and PI3K-AKT has potential as a treatment strategy for PI3Kβi/AKTi sensitive and resistant breast tumours.

Transcriptional and genetic alterations of cuproptosis-related genes correlated to malignancy and immune-infiltrate of esophageal carcinoma

Esophageal carcinoma (ESCA) is a common type of cancer with high mortality. Cuproptosis is a new type of cell death and is characterized by the dependence on mitochondrial respiration and protein lipoylation. However, the potential roles of cuproptosis-related genes (CRGs) in ESCA remain elusive. Here, we systematically assessed the transcriptional and genetic alterations of CRGs in ESCA. We identified a CRGs signature for ESCA patients. A 6-CRGs signature was constructed by the least absolute shrinkage and selection operator (LASSO) regression analysis along with the univariate cox regression analysis and differential genes analysis. The CRGs score could significantly stratify ESCA patients’ survival and a high CRGs score was significantly correlated with worse overall survival. Moreover, higher CRGs score indicated higher pathology grades and aberrant cell adhesion, possibly via the PI3K-AKT pathway, which could also underly their increased sensitivity to PI3K-AKT pathway inhibitors. In addition, patients with high CRGs tend to hold more mutation load and abnormal APOBEC mutation. Notably, a higher CRGs score was anomalously associated with more immune infiltration, which could explain its malignancy by increased PD-L1 stability and a higher proportion of bystander T cells. In conclusion, our report revealed the significance of cuproptosis in ESCA and may have therapeutic potential in activating the bystander T cells.

Abstract CT005: Safety and efficacy of olaparib combined to metronomic cyclophosphamide and metformin in recurrent advanced/metastatic endometrial cancer patients: ENDOLA trial

Abstract Objectives: In patients with recurrent advanced endometrial carcinomas (EC), innovative treatments are needed after platinum chemotherapy. EC are characterized by frequent defective DNA repair, along with alterations of PI3K-AKT-mTor, and IGF1R pathways. In preclinical studies, the activity of PARP inhibitor is increased by the inhibition of PI3K-AKT pathway. Metformin inhibits the PI3K-AKT-mTor signaling pathway, and reduces IGF1 circulating levels. Metronomic cyclophosphamide may increase the activity of PARP inhibitors through DNA alkylating and anti-angiogenic effects. ENDOLA trial was meant to assess the safety and efficacy of the triplet olaparib (PARP 1-3 inhibitor) + metronomic cyclophosphamide + metformin in patients with advanced EC Methods: ENDOLA trial (NCT02755844) was an academic French prospective multicenter phase I/II open-label dose-escalation study meant to assess the safety, the Recommended Phase II trial Dose (RP2D), and the efficacy of olaparib combined to metronomic cyclophosphamide 50 mg PO QD and metformin 500 mg PO TID in patients with recurrent advanced EC. In the phase I part, olaparib was dose-escalated from PO 150 mg to 300 mg BID with a continual reassessment method (CRM), aiming at defining the RP2D. In the phase II part, the cohort was expanded to assess the efficacy of the triplet in terms of non-progression rate at 10 weeks (H0= 20%; H1= 50%; 1-sided α risk=0.01; power = 90%). Results: From Sept 2016 to Nov 2019, 35 patients enrolled, and 31 were assessable (median age: 69, IQR: 62-72; endometrioid: n=18 (51.4%); serous: n=11 (35.5%); carcinosarcoma: n=2 (6.5%)). In the phase I part (17 patients), 1 DLT (5.9%) was observed: grade 3 fatigue during cycle 1 at 150 mg. Dose-escalation was possible up to 300 mg BID, that was the RP2D. In the phase II part (14 patients), the overall response rate was 20.8%, and the disease-control rate was 66.6 %. The non-progression rate at 10 weeks was 61.5% (95% CI 42.8-80.2). The median PFS was 5.1 months, including 7.5 months (5.1-8.9) for endometrioid, and 4.3 months (2.7-5.8) for serous carcinomas. Treatment-related serious adverse-events (AEs) occurred in 3 patients (grade 3 fatigue; grade 4 lymphopenia; grade 4 lymphopenia &amp; neutropenia). The most frequent grade 3-4 treatment-related AEs were lymphopenia (32.3%); anemia (16.1%); neutropenia (16.1%); and fatigue (12.9%). Conclusions: In heavily pre-treated patients with advanced EC, olaparib 300 mg BID could be safely combined to metformin 1500 mg/day and metronomic cyclophosphamide 50 mg/day. With a 61.5% non-progression rate at 10 weeks, the 1st-objective was reached. The 5.1 month median PFS (7.5 for endometrioid and 4.3 for serous) is promising compared to those observed with chemotherapy or immunotherapy-based combination in KEYNOTE-775 (Colombo et al. Proc ESMO 2021). Investigation in phase III is warranted. Citation Format: Benoit You, Alexandra Leary, Manuel Rodrigues, Philippe Follana, Cyril Abdeddaim, Florence Joly, Sylvie Bin, Laurent Villeneuve, Marine Alexandre, Florent Boutitie, Delphine Maucort-Boulch, Verane Schwiertz, Gilles Freyer. Safety and efficacy of olaparib combined to metronomic cyclophosphamide and metformin in recurrent advanced/metastatic endometrial cancer patients: ENDOLA trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT005.

STREM-1 promotes the phagocytic function of microglia to induce hippocampus damage via the PI3K\u2013AKT signaling pathway

Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is a soluble form of TREM-1 released during inflammation. Elevated sTREM-1 levels have been found in neuropsychiatric systemic lupus erythematosus (NPSLE) patients; yet, the exact mechanisms remain unclear. This study investigated the role of sTREM-1 in brain damage and its underlying mechanism. The sTREM-1 recombinant protein (2.5 μg/3 μL) was injected into the lateral ventricle of C57BL/6 female mice. After intracerebroventricular (ICV) injection, the damage in hippocampal neurons increased, and the loss of neuronal synapses and activation of microglia increased compared to the control mice (treated with saline). In vitro. after sTREM-1 stimulation, the apoptosis of BV2 cells decreased, the polarization of BV2 cells shifted to the M1 phenotype, the phagocytic function of BV2 cells significantly improved, while the PI3K–AKT signal pathway was activated in vivo and in vitro. PI3K–AKT pathway inhibitor LY294002 reversed the excessive activation and phagocytosis of microglia caused by sTREM-1 in vivo and in vitro, which in turn improved the hippocampus damage. These results indicated that sTREM-1 activated the microglial by the PI3K–AKT signal pathway, and promoted its excessive phagocytosis of the neuronal synapse, thus inducing hippocampal damage. sTREM-1 might be a potential target for inducing brain lesions.

TAL1 cooperates with PI3K/AKT pathway activation in T-cell acute lymphoblastic leukemia.

TAL1 is ectopically expressed in about 30% of T-cell acute lymphoblastic leukemia (T-ALL) due to chromosomal rearrangements leading to the STIL-TAL1 fusion genes or due to non-coding mutations leading to a de novo enhancer driving TAL1 expression. Analysis of sequence data from T-ALL cases demonstrates a significant association between TAL1 expression and activating mutations of the PI3K-AKT pathway. We investigated the oncogenic function of TAL1 and the possible cooperation with PI3K-AKT pathway activation using isogenic pro-T-cell cultures ex vivo and in vivo leukemia models. We found that TAL1 on its own suppressed T-cell growth, in part by affecting apoptosis genes, while the combination with AKT pathway activation reduced apoptosis and was strongly driving cell proliferation ex vivo and leukemia development in vivo. As a consequence, we found that TAL1+AKTE17K transformed cells are more sensitive to PI3K-AKT pathway inhibition compared to AKTE17K transformed cells, related to the negative effect of TAL1 in the absence of activated PI3K-AKT signaling. We also found that both TAL1 and PI3K-AKT signaling increased the DNA-repair signature in T cells resulting in synergy between PARP and PI3K-AKT pathway inhibition. In conclusion, we have developed a novel mouse model for TAL1+AKTE17K driven T-ALL development and have identified a vulnerability of these leukemia cells to PI3K-AKT and PARP inhibitors.

The immune impact of PI3K-AKT pathway inhibition in colorectal cancer.

154 Background: Our prior work has shown that PI3K-altered colorectal cancer (CRC), with PIK3CA mutation or PTEN loss, has increased expression of key immune checkpoints (including PD-L1) resulting in immune evasion, despite increased immune engagement. Here, we investigated the impact of PI3K-AKT inhibition on the immune repertoire of CRC. Methods: Multiplex immunofluorescence was performed using two Vectra panels [1: AE1/AE3, CD3, CD8, PD-1, PD-L1, CD68; and 2: AE1/AE3, CD3, CD8, Granzyme B (GzB), CD45RO, FoxP3] on paired biopsies (baseline and cycle 1 day 15) from 6 patients with PI3K-altered metastatic CRC (mCRC) treated with AKT inhibitor, MK2206 (200 mg oral weekly), on a phase 2 clinical trial. Separately, one million CT26 CRC cells were implanted in BALB/C-e mice. After 48 hours, 10 mice/group were randomized for treatment with pan-PI3K inhibitor copanlisib (C, 10 mg/Kg IV 2x/week), anti-PD-1 (P, 200 µg IP 2x/week), copanlisib + anti-PD-1 (C+P), or control (Ct), for 21 days. Mouse tumors were stained with 6-plex immunohistochemistry (CD3, CD8, PD-L1, Ki67, GzB, AE1/AE3). Data were analyzed using related-samples Wilcoxon Signed-Rank test, Mann-Whitney U test, Kruskal-Wallis test, and Student’s t-test, as appropriate. Results: In PI3K-altered mCRC patients, AKT inhibition resulted in a trend towards increased median densities of intratumoral CD8+ T cells (0.8 vs 4.8 density/mm2, P = 0.14) and memory T cells (0 vs 10.3, P = 0.07), and decreased density of macrophages (12.4 vs 0, P = 0.07). No antigen experienced T cells were seen and activated CD8+ T cells were present in 1 patient only. In CT26 mice, PI3K and PD-1 co-inhibition resulted in the smallest mean tumor volumes (C+P 12% of Ct vs C 40% and P 42% of Ct, P &lt; 0.05 for both), and the highest median % of intratumoral CD8+Ki67+ T cells as compared to all other treatment arms (C+P 1.6% vs C 0.5%, P 0.4%, Ct 0.6%, P &lt; 0.05 for each pairwise comparison). C+P also increased the % of total CD3+ and CD8+ cells as compared to Ct and C (P &lt; 0.05 for all). C alone did not increase immune infiltration in this non-PI3K activated model. Conclusions: PI3K-AKT pathway inhibition has the potential to improve effector T cell infiltration in PI3K-altered CRC. PI3K inhibitor synergizes with anti-PD-1 to improve treatment efficacy and CD8+ T cell proliferation. The mechanisms behind this immune repertoire shift are yet to be elucidated, such as via cytokine modulation. Therapeutic approaches to activate the proliferating CD8+ cells would be useful, and may require PI3Kα/β specific inhibitors to allow early T cell activation through PI3Kδ/γ isoforms.

515MO A phase I trial of durvalumab (Durv) in combination with olaparib (Ola) and capivasertib (Cap) in patients (pts) with advanced or metastatic cancers (Ca) (MEDIPAC)

Tumor-specific homologous recombination (HR) DNA defects and the phosphatidylinositol 3-kinase (PI3K)-AKT pathway are commonly implicated in tumorigenesis, and preclinical studies have shown synergistic effects of poly (ADP-ribose) polymerase (PARP) with PI3K-AKT inhibitors. Both pathways modulate the tumor immune microenvironment by regulation of tumor-infiltrating lymphocytes and reduction of Treg cells. We hypothesized that triplet combination of immunotherapy with PARP and PI3K-AKT pathway inhibition is tolerable and may demonstrate activity in pts with relevant pathway defects.

Ursodeoxycholic acid shows antineoplastic effects in bile duct cancer cells via apoptosis induction; p53 activation; and EGFR-ERK, COX-2, and PI3K-AKT pathway inhibition.

Unlike in normal cells, ursodeoxycholic acid (UDCA) causes apoptosis rather than protection in cancer cells. Aim of this study was to demonstrate whether UDCA actually inhibits proliferation and induces apoptosis in bile duct cancer cells; the effect of UDCA on the expression of COX-2, PI3K/AKT, ERK, and EGFR; how UDCA affects cancer cell invasiveness and metastasis, since these effects are not established in bile duct cancer cells. SNU-245 cells (human extrahepatic bile duct cancer cells) were cultured. MTT assays were performed to evaluate the effect of UDCA on the cell proliferation. A cell death detection enzyme-linked immunosorbent assay and a caspase-3 activity assay were used to determine apoptosis. Western blot analysis measured expression levels of various proteins. The invasiveness of the cancer cells was evaluated by invasion assay. In cultured bile duct cancer cells, UDCA suppressed cell proliferation in bile duct cancer cells by inducing apoptosis and p53 activation, blocking deoxycholic acid (DCA)-induced activated EGFR-ERK signaling and COX-2, inhibiting DCA-induced activated PI3K-AKT signaling, and suppressing the invasiveness of bile duct cancer cells. In addition, a MEK inhibitor impaired UDCA-induced apoptosis in bile duct cancer cells. UDCA has antineoplastic and apoptotic effects in bile duct cancer cells. Thus, UDCA could be a chemopreventive agent in patients with a high risk of cancer, and/or a therapeutic option that enhances other chemotherapeutics.

M2 macrophages, but not M1 macrophages, support megakaryopoiesis by upregulating PI3K-AKT pathway activity

Dysfunctional megakaryopoiesis hampers platelet production, which is closely associated with thrombocytopenia (PT). Macrophages (MФs) are crucial cellular components in the bone marrow (BM) microenvironment. However, the specific effects of M1 MФs or M2 MФs on regulating megakaryocytes (MKs) are largely unknown. In the current study, aberrant BM-M1/M2 MФ polarization, characterized by increased M1 MФs and decreased M2 MФs and accompanied by impaired megakaryopoiesis-supporting abilities, was found in patients with PT post-allotransplant. RNA-seq and western blot analysis showed that the PI3K-AKT pathway was downregulated in the BM MФs of PT patients. Moreover, in vitro treatment with PI3K-AKT activators restored the impaired megakaryopoiesis-supporting ability of MФs from PT patients. Furthermore, we found M1 MФs suppress, whereas M2 MФs support MK maturation and platelet formation in humans. Chemical inhibition of PI3K-AKT pathway reduced megakaryopoiesis-supporting ability of M2 MФs, as indicated by decreased MK count, colony-forming unit number, high-ploidy distribution, and platelet count. Importantly, genetic knockdown of the PI3K-AKT pathway impaired the megakaryopoiesis-supporting ability of MФs both in vitro and in a MФ-specific PI3K-knockdown murine model, indicating a critical role of PI3K-AKT pathway in regulating the megakaryopoiesis-supporting ability of M2 MФs. Furthermore, our preliminary data indicated that TGF-β released by M2 MФs may facilitate megakaryopoiesis through upregulation of the JAK2/STAT5 and MAPK/ERK pathways in MKs. Taken together, our data reveal that M1 and M2 MФs have opposing effects on MKs in a PI3K-AKT pathway-dependent manner, which may lead to new insights into the pathogenesis of thrombocytopenia and provide a potential therapeutic strategy to promote megakaryopoiesis.

A pharmacophore-based classification better predicts the outcomes of HER2-negative breast cancer patients receiving the anthracycline- and/or taxane-based neoadjuvant chemotherapy.

AimsPrognosis of patients for human epidermal growth factor receptor 2 (HER2)‐negative breast cancer post neoadjuvant chemotherapy is not well understood. The aim of this study was to develop a novel pharmacophore‐based signature to better classify and predict the risk of HER2‐negative patients after anthracycline‐and/or taxane‐based neoadjuvant chemotherapy (NACT).Main methodsAnthracycline and taxane pharmacophore‐based genes were obtained from PharmMapper. Drug‐targeted genes (DTG) related clinical and bioinformatic analyses were undertaken in four GEO datasets.Key findingsWe used 12 genes from the pharmacophore to develop a DTG score (DTG‐S). The DTG‐S classification exhibited significant prognostic ability with respect to disease free survival (DFS) for HER2‐negative patients who receive at least one type of neoadjuvant chemotherapy that included anthracycline and/or taxane. DTG‐S associated with a high predictive ability for pathological complete response (pCR) as well as for prognosis of breast cancer. Using the DTG‐S classification in other prediction models may improve the reclassification accuracy for DFS. Combining the DTG‐S with other clinicopathological factors may further improve its predictive ability of patients’ outcomes. Gene ontology and KEGG pathway analysis showed that the biological processes of DTG‐S high group were associated with the cell cycle, cell migration, and cell signal transduction pathways. Targeted drug analysis shows that some CDK inhibitors and PI3K‐AKT pathway inhibitors may be useful for high DTG‐S patients.SignificanceThe DTG‐S classification adds prognostic and predictive information to classical parameters for HER2‐negative patients who receive anthracycline‐and/or taxane‐based NACT, which could improve the patients’ risk stratification and may help guide adjuvant treatment.