Computational study on subfamilies of piperidine derivatives: QSAR modelling, model external verification, the inter-subset similarity determination, and structure-based drug designing

A new subset of furan-pyrazole piperidine derivatives was used for QSAR model development. These compounds exhibit good Akt1 inhibitory activity; moreover, antiproliferative activities in vitro against OVCAR-8 (Human ovarian carcinoma cells) and HCT116 (human colon cancer cells), were confirmed for them. Based on the relevant three-dimensional (3D) and 2D autocorrelation descriptors, selected by genetic algorithm (GA), multiple linear regression (MLR) was established on half maximal-inhibitory concentration (IC₅₀), in Akt1 and cancer cell lines independently. Robustness, stability, and predictive ability of the models were evaluated using external and internal validation (r²: 0.742-0.832, Q²_LOO: 0.684-0.796, RMSE: 0.247-0.299, F: 32.283-57.578, and r²_y-random: 0.049-0.080). Furthermore, in the new strategy, each of the evaluated models was generalized to two other subfamilies of piperidines to simultaneously compare the activities and structural similarity of these three subsets. Probably, structural similarity can be more considered as a criterion of similarity in the mechanism of action. Also, external verification of suggested predictive models was performed by another subset. Finally, by focusing on M64 as the most potent in vivo antitumor compound, 15 new derivatives were designed and six potent candidates were proposed for further investigation.

Hepatitis E viral infection regulates estrogen signaling pathways: Inhibition of the cAMPK-PKA-CREB and PI3K-AKT-mTOR signaling pathways

Hepatitis E virus (HEV) infection has become a global concern with high mortality rates among pregnant women, especially those in their third trimester of pregnancy. Estrogen plays an important role in mediating the body, regulating physiological and pathological processes. Estrogen is activated by binding to estrogen receptors (ERs) and mediates rapid signaling events by pathways that involve transmembrane ERs. Our previous study had confirmed that high estrogen levels during pregnancy are associated with high HEV titers. However, the association between HEV infection and estrogen signaling pathways remains unclear. In the present study, the regulation of estrogen signaling pathways by HEV infection was evaluated. Results demonstrated that HEV infection significantly inhibits the cAMP-PKA-CREB and PI3K-AKT-mTOR signaling pathways, but is independent of the Ras-Raf-MEK-ERK signaling pathway. In summary, the increasing estrogen levels and highly activated ERα during pregnancy aggravates HEV replication. The exacerbation of HEV replication, in turn, inhibits ERα expression and suppresses both cAMP-PKA-CREB and PI3K-AKT-mTOR signaling pathways.

The PI3K/Akt Pathway: Emerging Roles in Skin Homeostasis and a Group of Non-Malignant Skin Disorders

The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway regulates cell proliferation, differentiation, and migration, along with angiogenesis and metabolism. Additionally, it could mediate skin development and homeostasis. There is much evidence to suggest that dysregulation of PI3K/Akt pathway is frequently associated with several human cutaneous malignancies like malignant melanoma (MM), basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (SCC), as well as their poor outcomes. Nevertheless, emerging roles of PI3K/Akt pathway cascade in a group of common non-malignant skin disorders including acne and psoriasis, among others, have been recognized. The enhanced understanding of dysfunction of PI3K/Akt pathway in patients with these non-malignant disorders has offered a solid foundation for the progress of updated therapeutic targets. This article reviews the latest advances in the roles of PI3K/Akt pathway and their targets in the skin homeostasis and progression of a wide range of non-malignant skin disorders and describes the current progress in preclinical and clinical researches on the involvement of PI3K/Akt pathway targeted therapies.

Rosmarinic Acid Induces Proliferation Suppression of Hepatoma Cells Associated with NF-κB Signaling Pathway

BACKGROUND

Rosmarinic acid (RA) is a natural phenolic compound that acts as a Fyn inhibitor by 53 homology modeling of the human Fyn structure. Therefore, the apoptosis mechanism related to  NF-κB signaling pathway induced by RA in HepG2 was investigated.

METHODS

The cell growth, apoptosis, and proliferation of HepG2 regulated by various concentrations of RA were studied. The proteins expression of MMP-2, MMP-9, PI3K, AKT, NF-κB, and apoptosis-related proteins Bax, Bcl-2, cleaved caspase-3 were detected.

RESULTS

RA significantly reduced proliferation rates, inhibited migration and invasion, and decreased the expressions of invasion-related factors, such as matrix metalloproteinase (MMP)-2 and MMP-9. TUNEL staining revealed that RA resulted in a dose-dependent increase of HepG2 cell apoptosis. In line with this finding, the expression of apoptosis suppressor protein Bcl-2 was downregulated and that of the pro-apoptotic proteins Bax and cleaved caspase-3 was increased. In addition, we found that the phosphatidylinositol 3-kinase (PI3K)/Akt/nuclear factor kappa B (NF-κB) signaling pathway was involved in RA-mediated inhibition of HepG2 cell metastasis.

CONCLUSION

Our study identified that  RA as a drug candidate for the treatment of HCC.

Combined Targeting of AKT and mTOR Synergistically Inhibits Formation of Primary Colorectal Carcinoma Tumouroids In Vitro: A 3D Tumour Model for Pre-therapeutic Drug Screening

BACKGROUND

Pre-therapeutic analysis of three-dimensional spheroid cultures of primary tumour samples is a promising approach of assessing susceptibility to potential treatment. The phosphatidylinositol-3-kinase/AKT serine/threonine kinase/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling pathway is frequently activated in colorectal cancer (CRC). In previous work, we showed combined inhibition of AKT and mTOR to be highly synergistic in cell lines from patients with hepatocellular carcinoma and cholangiocarcinoma in vitro as well as in vivo in murine xenograft tumour models.

MATERIALS AND METHODS

Patient-derived xenograft colorectal carcinoma cell lines HROC80 T1 M1, HROC147 T0 M1, HROC147Met, HROC277 T0 M1 and HROC277Met2 were treated with AKT inhibitor MK2206, mTOR inhibitor RAD001 or the combination of both drugs. The sensitivity of these cell lines to inhibition was evaluated by calculation of combinatory indices after bromodeoxyuridine assays and analysis of the respective pathways by western blotting. Furthermore, the dual inhibition of AKT and mTOR was confirmed in vivo in a xenograft mouse model. Additionally, primary CRC samples of four patients were embedded in a three-dimensional matrix and the sensitivity of these samples was analyzed by measurement of the spheroid area.

RESULTS

In this study, we demonstrate that combined treatment with MK2206 and RAD001 resulted in strong synergistic effects on growth of several primary CRC cell lines and reduced the growth of a patient-derived CRC xenograft in a xenotransplantation mouse model in vivo. Interestingly, the response to treatment varied between cell lines derived from the primary lesion and a liver metastasis of the same patient. In addition, combined treatment with AKT and mTOR inhibitors resulted in a synergistic inhibition of tumouroid growth in all four of the primary patient samples, analyzed in a three-dimensional spheroid model in vitro.

CONCLUSION

Our data demonstrate that combined treatment with AKT and mTOR inhibitors exhibits synergistic effects on proliferation of cell lines and primary tumour cells from patients with CRC and may be a promising approach for the treatment of CRC.

miRNA-93-5p Promotes Gemcitabine Resistance in Pancreatic Cancer Cells by Targeting the PTEN-Mediated PI3K/Akt Signaling Pathway

OBJECTIVE

To investigate the role and potential underlying mechanism of miR-93-5p in the carcinogenesis and gemcitabine resistance of pancreatic cancer (PC) cells.

METHODS

We generated a gemcitabine-resistant PC cell line Bxpc-3/GemR following prolonged gemcitabine exposure to its parental gemcitabine-sensitive counterpart Bxpc-3/Par. Cell viability was monitored by MTS assay. Transfection was performed using Lipofectamine 3000 reagent. Cell apoptosis and rhodamine 123 fluorescence were detected by flow cytometry. Luciferase activities were measured using the luciferase reporter gene assay. Expression analysis was carried out by qRT-PCR and western blot.

RESULTS

Significantly increased viability and enhanced expression of the multi-drug resistance-1 (MDR1) gene were observed in Bxpc-3/GemR cells, in which miR-93-5p is considerably upregulated, compared with Bxpc-3/Par cells. Downregulation of miR-93-5p inhibited cell viability, induced cell apoptosis, and decreased MDR1 expression in Bxpc-3/GemR cells, whereas upregulation essentially reversed these properties in Bxpc-3/Par cells. We further confirmed that PTEN was a direct target of miR-93-5p, and overexpression of miR-93-5p was accompanied by a significant increase in the phosphorylation of Akt expression in the Bxpc-3/Par cells. Moreover, inhibition of PI3K/Akt signaling diminished MDR1 expression.

CONCLUSION

These observations suggest that miR-93-5p modulates tumorigenesis and gemcitabine resistance in PC cells via targeting the PTEN/PI3K/Akt signaling pathway.

Diversity-oriented synthesis through gamma radiolysis: Preparation of unusual ecdysteroid derivatives activating Akt and AMPK in skeletal muscle cells

Gamma-ray radiation is a unique way to induce chemical transformations of bioactive compounds. In the present study, we pursued this approach to the diversity-oriented synthesis of analogs of 20-hydroxyecdysone (20E), an abundant ecdysteroid with a range of beneficial, non-hormonal bioactivities in mammals including humans. Gamma irradiations of aqueous solutions of 20E were conducted either in N₂- or N₂O-saturated solutions. Centrifugal partition chromatography was used to fractionate crude resulting irradiated materials using a biphasic solvent system composed of tert-butyl alcohol - ethyl acetate - water (0.45:0.9:1, v/v/v) in ascending mode. Subsequently, the products were purified by RP-HPLC. Fourteen ecdysteroids, including five new compounds, were isolated, and their structure were elucidated by 1D and 2D NMR and HRMS. Compounds 2-4, 7, 9, 12 and 15 were tested for their capacity to increase the Akt- and AMPK-phosphorylation of C2C12 murine skeletal myotubes in vitro. The compounds were similarly active on Akt as their parent compound. Stachysterone B (7) and a new ring-rearranged compound (12) were more potent than 20E in activating AMPK, indicating a stronger cytoprotective effect. Our results demonstrate the use of gamma irradiation in expanding the chemical diversity of ecdysteroids to obtain new, unusual bioactive metabolites.

Effect of Whole Tissue Culture and Basic Fibroblast Growth Factor on Maintenance of Tie2 Molecule Expression in Human Nucleus Pulposus Cells

Previous work showed a link between Tie2⁺ nucleus pulposus progenitor cells (NPPC) and disc degeneration. However, NPPC remain difficult to maintain in culture. Here, we report whole tissue culture (WTC) combined with fibroblast growth factor 2 (FGF2) and chimeric FGF (cFGF) supplementation to support and enhance NPPC and Tie2 expression. We also examined the role of PI3K/Akt and MEK/ERK pathways in FGF2 and cFGF-induced Tie2 expression. Young herniating nucleus pulposus tissue was used. We compared WTC and standard primary cell culture, with or without 10 ng/mL FGF2. PI3K/Akt and MEK/ERK signaling pathways were examined through western blotting. Using WTC and primary cell culture, Tie2 positivity rates were 7.0 ± 2.6% and 1.9 ± 0.3% (p = 0.004), respectively. Addition of FGF2 in WTC increased Tie2 positivity rates to 14.2 ± 5.4% (p = 0.01). FGF2-stimulated expression of Tie2 was reduced 3-fold with the addition of the MEK inhibitor PD98059 (p = 0.01). However, the addition of 1 μM Akt inhibitor, 124015-1MGCN, only reduced small Tie2 expression (p = 0.42). cFGF similarly increased the Tie2 expression, but did not result in significant phosphorylation in both the MEK/ERK and PI3K/Akt pathways. WTC with FGF2 addition significantly increased Tie2 maintenance of human NPPC. Moreover, FGF2 supports Tie2 expression via MEK/ERK and PI3K/Akt signals. These findings offer promising tools and insights for the development of NPPC-based therapeutics.

Upregulated hsa_circRNA_100269 inhibits the growth and metastasis of gastric cancer through inactivating PI3K/Akt axis

The pathogenesis of GC involves the complex networking of multiple signaling pathways; however, the detailed mechanisms of tumorigenesis of GC remains largely unknown. Therefore, it is necessary to explore novel diagnostic/prognostic biomarkers for GC. In this study, the levels of hsa_circRNA_100269 in gastric cancer (GC) samples and cells were examined, and its effects on the biological functions of GC cells were elucidated. The levels of hsa_circRNA_100269 in specimens/cell lines were examined using RT-qPCR. Cell models with hsa_circRNA_100269 overexpression or knockdown were generated using lentiviral vectors. Cell viability was determined by MTT assay; cell migratory/invasive activity was evaluated using wound healing/Transwell assay. Cell cycle arrest and apoptosis were assessed by flow cytometry; expression of associated markers involved in cell apoptosis, EMT and the PI3K/Akt signaling were determined by RT-qPCR/immunoblotting. In vivo study was also performed using hsa_circRNA_100269 knockout mice. Our findings revealed downregulation of hsa_circRNA_100269 in GC tissues compared to non-cancerous control. Additionally, the levels of PI3K were remarkably elevated in GC tissues, where hsa_circRNA_100269 and PI3K was negatively correlated. Moreover, the expression of hsa_circRNA_100269 was associated with histology grade and occurrence of metastasis in GC patients. In addition, hsa_circRNA_100269 was downregulated in GC cells compared to normal gastric epithelial cells. Overexpressed hsa_circRNA_100269 notably inhibited the proliferation, migration, invasion and EMT of GC cells, whereas cell cycle arrest at G0/G1 phase was promoted and cell apoptosis was enhanced. Moreover, the PI3K/Akt signaling was involved in hsa_circRNA_100269-regulated GC cell proliferation, migration, invasion, EMT and apoptosis. Knockdown of hsa_circRNA_100269 also remarkably induced tumor growth in mouse model. In summary, our findings indicated that the levels of hsa_circRNA_100269 were reduced in GC. Furthermore, hsa_circRNA_100269 could suppress the development of GC by inactivating the PI3K/Akt pathway. More importantly, hsa_circRNA_100269/PI3K/Akt axis may be a novel therapeutic candidate for GC treatment.

PI3K/AKT/mTOR and TLR4/MyD88/NF-κB Signaling Inhibitors Attenuate Pathological Mechanisms of Allergic Asthma

Asthma is an inflammatory airway disease wherein bronchoconstriction, airway inflammation, and airway obstruction during asthma attacks are the main problems. It is recognized that imbalance of Th1/Th2 and Th17/Treg is a critical factor in asthma pathogenesis. Manipulation of these with signaling molecules such as mTOR, PI3K, Akt, and MyD88 can control asthma. Mouse model of allergic asthma was produced and treated with ketamine, metformin, metformin and ketamine, triciribine, LY294002, and torin2. MCh challenge test, BALf's Eos Count, the IL-4, 5, INF-γ, eicosanoid, total IgE levels were determined. The MUC5a, Foxp3, RORγt, PI3K, mTOR, Akt, PU.1, and MyD88 gene expressions and histopathology study were done. Asthma groups that were treated with all six components had reduced Penh value, total IgE, IL-4 and IL-5 levels, MUC5a, RORγt, MyD88 and mTOR expression, goblet cell hyperplasia, and mucus hyper-secretion. The eosinophil percentage and Cys-LT level were decreased by metformin and ketamine, triciribine, LY294002, and torin2. The level of IFN-γ was increased in triciribine, LY294002, and torin2. Metformin, metformin and ketamine, triciribine, LY294002, and torin2 reduced Akt and PI3K expression, peribronchial and perivascular inflammation, and increased expression of Foxp3. Torin2 had an effect on PU.1 expression. Inhibition of PI3K/AKT/mTOR and TLR4/MyD88/NF-κB signaling with targeted molecules can attenuate asthma pathology and play an important role in airways protection.

Novel Semi-Synthetic Cu (II)-Cardamonin Complex Exerts Potent Anticancer Activity against Triple-Negative Breast and Pancreatic Cancer Cells via Inhibition of the Akt Signaling Pathway

Cardamonin is a polyphenolic natural product that has been shown to possess cytotoxic activity against a variety of cancer cell lines. We previously reported the semi-synthesis of a novel Cu (II)–cardamonin complex (19) that demonstrated potent antitumour activity. In this study, we further investigated the bioactivity of 19 against MDA-MB-468 and PANC-1 cancer cells in an attempt to discover an effective treatment for triple-negative breast cancer (TNBC) and pancreatic cancer, respectively. Results revealed that 19 abolished the formation of MDA-MB-468 and PANC-1 colonies, exerted growth-inhibitory activity, and inhibited cancer cell migration. Further mechanistic studies showed that 19 induced DNA damage resulting in gap 2 (G2)/mitosis (M) phase arrest and microtubule network disruption. Moreover, 19 generated reactive oxygen species (ROS) that may contribute to induction of apoptosis, corroborated by activation of caspase-3/7, PARP cleavage, and downregulation of Mcl-1. Complex 19 also decreased the expression levels of p-Akt and p-4EBP1, which indicates that the compound exerts its activity, at least in part, via inhibition of Akt signalling. Furthermore, 19 decreased the expression of c-Myc in PANC-1 cells only, which suggests that it may exert its bioactivity via multiple mechanisms of action. These results demonstrate the potential of 19 as a therapeutic agent for TNBC and pancreatic cancer.

Ceritinib increases sensitivity of AKT inhibitors to gastric cancer

Gastric cancer (GC), known for high morbidity and mortality, is poorly prognosed with traditional chemotherapy and biological agents. Current studies have found that over-activation of AKT is a common molecular characteristic in GC. Although the development of this targeted inhibitor has entered clinical phases, limited success is reported because of its compensatory signaling pathways. Here, we found that GC cell lines with high phosphorylation of AKT show different sensitivity to AKT inhibitors (AKTis), but a reduction of p-GSK3β related sensitivity of AKTis in GC cells. Besides, we revealed that Ceritinib exerted a strongly synergistic antitumor effect with AKT inhibitors both in vitro and in vivo. Obviously, Ceritinib improved the sensitivity of Capivasertib (AZD5363, AKTs) and Afuresertib (GSK2110183, AKTis) in gastric cancer cells, as illustrated by a significant reduction in the GC cell proliferation and enhanced apoptosis. The drug combination showed tumor regression in BALB/c (nu/nu) mouse MKN45 (Gastric cancer), tumor model. Also, the combination strategy indicated significantly low p-AKT levels due to AKTis compensation and reduced the levels of p-GSK3β in both GC cell lines and GC patient-derived cells. These findings may provide a novel combination strategy for gastric cancer treatment.

Discovery of novel ceramide analogs with favorable pharmacokinetic properties and combination with AKT inhibitor against colon cancer

Ceramides have emerged as potential therapeutic option with novel mechanism to affect the proliferation, differentiation, senescence, and apoptosis of cancer cells through regulation of multiple signal transduction. Aiming at the improvement of the apoptosis activity and pharmacokinetic profiles of ceramides, a novel series of ceramide analogs were developed through structure simplification and conformation restriction. Among them, compound 12 bearing an alkoxyl naphthyl motif, with favorable rat pharmacokinetic properties, showed better anti-proliferative activity against various colon cancer cells (IC50 ∼20 μM) than other ceramide analogues, as well as the synergistic effect combined with AKT inhibitor MK2206. Additionally, we demonstrated that this combination therapy promoted caspase 3-dependent apoptotic pathway and intensified cell cycle arrest in the G0/G1 phase. Furthermore, the combination of compound 12 and MK2206 displayed synergistic anti-tumor effect in vivo.

Identification of a novel conserved signaling motif in CD200 receptor required for its inhibitory function

The inhibitory signaling of CD200 receptor 1 (CD200R) has been attributed to its NPxY signaling motif. However, NPxY-motifs are present in multiple protein families and are mostly known to mediate protein trafficking between subcellular locations rather than signaling. Therefore, we investigated whether additional motifs specify the inhibitory function of CD200R. We performed phylogenetic analysis of the intracellular domain of CD200R in mammals, birds, bony fish, amphibians and reptiles. Indeed, the tyrosine of the NPxY-motif is fully conserved across species, in line with its central role in CD200R signaling. In contrast, P295 of the NPxY-motif is not conserved. Instead, a conserved stretch of negatively charged amino acids, EEDE279, and two conserved residues P285 and K292 in the flanking region prior to the NPxY-motif are required for CD200R mediated inhibition of p-Erk, p-Akt308, p-Akt473, p-rpS6 and LPS-induced IL-8 secretion. Altogether, we show that instead of the more common NPxY-motif, CD200R signaling can be assigned to a unique signaling motif in mammals defined by: EEDExxPYxxYxxKxNxxY.

Design, synthesis and biological evaluation of anilide (dicarboxylic acid) shikonin esters as antitumor agents through targeting PI3K/Akt/mTOR signaling pathway

Triple-negative breast cancer (TNBC) has an unfavorable prognosis attribute to its low differentiation, rapid proliferation and high distant metastasis rate. PI3K/Akt/mTOR as an intracellular signaling pathway plays a key role in the cell proliferation, migration, invasion, metabolism and regeneration. In this work, we designed and synthesized a series of anilide (dicarboxylic acid) shikonin esters targeting PI3K/Akt/mTOR signaling pathway, and assessed their antitumor effects. Through three rounds of screening by computer-aided drug design method (CADD), we preliminarily obtained sixteen novel anilide (dicarboxylic acid) shikonin esters and identified them as excellent compounds. CCK-8 assay results demonstrated that compound M9 exhibited better antiproliferative activities against MDA-MB-231, A549 and HeLa cell lines than shikonin (SK), especially for MDA-MB-231 (M9: IC₅₀ = 4.52 ± 0.28 μM; SK: IC₅₀ = 7.62 ± 0.26 μM). Moreover, the antiproliferative activity of M9 was better than that of paclitaxel. Further pharmacological studies showed that M9 could induce apoptosis of MDA-MB-231 cells and arrest the cell cycle in G2/M phase. M9 also inhibited the migration of MDA-MB-231 cells by inhibiting Wnt/β-catenin signaling pathway. In addition, western blot results showed that M9 could inhibit cell proliferation and migration by down-regulating PI3K/Akt/mTOR signaling pathway. Finally, a three-dimensional quantitative structure-activity relationship (3D-QSAR) model was also constructed to provide a basis for further development of shikonin derivatives as potential antitumor drugs through structure-activity relationship analysis. To sum up, M9 could be a potential candidate for TNBC therapy.

Moscatilin Inhibits Metastatic Behavior of Human Hepatocellular Carcinoma Cells: A Crucial Role of uPA Suppression via Akt/NF-κB-Dependent Pathway

Hepatocellular carcinoma (HCC) frequently shows early invasion into blood vessels as well as intrahepatic metastasis. Innovations of novel small-molecule agents to block HCC invasion and subsequent metastasis are urgently needed. Moscatilin is a bibenzyl derivative extracted from the stems of a traditional Chinese medicine, orchid Dendrobium loddigesii. Although moscatilin has been reported to suppress tumor angiogenesis and growth, the anti-metastatic property of moscatilin has not been elucidated. The present results revealed that moscatilin inhibited metastatic behavior of HCC cells without cytotoxic fashion in highly invasive human HCC cell lines. Furthermore, moscatilin significantly suppressed the activity of urokinase plasminogen activator (uPA), but not matrix metalloproteinase (MMP)-2 and MMP-9. Interestingly, moscatilin-suppressed uPA activity was through down-regulation the protein level of uPA, and did not impair the uPA receptor and uPA inhibitory molecule (PAI-1) expressions. Meanwhile, the mRNA expression of uPA was inhibited via moscatilin in a concentration-dependent manner. In addition, the expression of phosphorylated Akt, rather than ERK1/2, was inhibited by moscatilin treatment. The expression of phosphor-IκBα, and -p65, as well as κB-luciferase activity were also repressed after moscatilin treatment. Transfection of constitutively active Akt (Myr-Akt) obviously restored the moscatilin-inhibited the activation of NF-κB and uPA, and cancer invasion in HCC cells. Taken together, these results suggest that moscatilin impedes HCC invasion and uPA expression through the Akt/NF-κB signaling pathway. Moscatilin might serve as a potential anti-metastatic agent against the disease progression of human HCC.

Isochromanoindolenines suppress triple-negative breast cancer cell proliferation partially via inhibiting Akt activation

As the most malignant subtype of breast cancers, triple-negative breast cancer (TNBC) lacks effective targeted therapeutics clinically to date. In this study, one lead compound FZU-0025-065 with isochromanoindolenine scaffold was identified by a cell-based screening. Among nine breast cancer cell lines tested, TNBC are the most sensitive cell lines to FZU-0025-065. FZU-0025-065 inhibits TNBC cell growth in a time- and dosage-dependent manner. FZU-0025-065 suppresses the expression of cell cycle dependent kinase 4 (CDK4), Cyclin D1 and Cyclin B1; meanwhile, elevates the expression of cell cycle dependent kinase inhibitor p21 and p27. Importantly, we found that FZU-0025-065 suppresses AKT activation in a time- and dosage-dependent manner. Over-expression of constitutive active AKT partially rescues FZU-0025-065 induced cell growth inhibition in MDA-MB-468 cells, indicating FZU-0025-065 suppresses TNBC cell growth partially via inhibiting AKT activation. Finally, FZU-0025-065 suppresses TNBC cell growth in a xenograft mouse model. Taken together, our findings suggested that isochromanoindolenine derivative FZU-0025-065 inhibits TNBC via suppressing the AKT signaling and that FZU-0025-065 may be useful for TNBC treatment.

Involvement of GPR30 in protection effect of Dexmedetomidine against myocardial ischemia/reperfusion injury in rat via AKT pathway

Acute myocardial infarction (AMI) is a heart disease that seriously threatens human health. Dexmedetomidine (DEX) has a certain protective effect on cardiac injury. This study investigated the cardioprotective effect of DEX and its potential molecular mechanism in vivo and in vitro. The results showed that DEX could significantly increase the viability of hypoxia/reoxygenation (H/R) treated cardiomyocytes and reduce oxidative damage and apoptosis. Further molecular mechanism analysis showed that the above cardiac protective effects may be related to Akt signaling pathway. In addition, the expression of G-Protein Receptor 30 (GPR30) was promoted after H/R treatment. However, knockdown of GPR30 by shRNA significantly counteracted the cardioprotective effect of DEX. Meanwhile, we constructed a rat model of AMI to investigate the role of GPR30 in vivo. The results showed that DEX significantly reduced the infarct size, and GPR30 agonist G1 enhanced the protective effect of DEX on heart. On the contrary, protein kinase B (AKT) inhibitor LY294002 counteracted the protective effect of DEX on heart, suggesting that GPR30 enhanced the protective effect of DEX on ischemia-reperfusion induced heart injury by regulating AKT related pathways. In conclusion, our study provides a potential target for the clinical treatment of AMI.

Apelin ameliorated acute heart failure via inhibiting endoplasmic reticulum stress in rabbits

This study aimed to investigate whether inhibition of endoplasmic reticulum stress (ERS) mediated the ameliorative effect of apelin on acute heart failure (AHF). Rabbit model of AHF was induced by sodium pentobarbital. Cardiac dysfunction and injury were detected in the rabbit models of AHF, including impaired hemodynamic parameters and increased levels of CK-MB and cTnI. Apelin treatment dramatically improved cardiac impairment caused by AHF. ERS, indexed by increased GRP78, CHOP, and cleaved-caspase12 protein levels, was simultaneously attenuated by apelin. Apelin also could ameliorate increased protein levels of cleaved-caspase3 and Bax, and improved decreased protein levels of Bcl-2. Two common ERS stimulators, tunicamycin (Tm) and dithiothreitol (DTT) blocked the ameliorative effect of apelin on AHF. Phosphorylated Akt levels increased after apelin treatment in the rabbit models of AHF. The Akt signaling inhibitors wortmannin and LY294002 could block the cardioprotective effect of apelin, which could be relieved by ERS inhibitor 4-phenyl butyric acid (4-PBA). The aforementioned beneficial effects of apelin could all be blocked by APJ receptor antagonist F13A. 4-PBA and SC79, an Akt activator, can restore the ameliorative effect of apelin on AHF blocked by F13A. Apelin treatment dramatically ameliorated cardiac impairment caused by AHF, which might be mediated by APJ/Akt/ERS signaling pathway. These results will shed new light on AHF therapy.

Effect of Oxaliplatin, Olaparib and LY294002 in Combination on Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) has a poor prognosis as the therapy has several limitations, most importantly, treatment resistance. In this study we examined the different responses of triple-negative breast cancer line MDA-MB-231 and hormone receptor-positive breast cancer line MCF7 to a combined treatment including olaparib, a poly-(ADP ribose) polymerase (PARP) inhibitor, oxaliplatin, a third-generation platinum compound and LY294002, an Akt pathway inhibitor. We applied the drugs in a single, therapeutically relevant concentration individually and in all possible combinations, and we assessed the viability, type of cell death, reactive oxygen species production, cell-cycle phases, colony formation and invasive growth. In agreement with the literature, the MDA-MB-231 cells were more treatment resistant than the MCF7 cells. However, and in contrast with the findings of others, we detected no synergistic effect between olaparib and oxaliplatin, and we found that the Akt pathway inhibitor augmented the cytostatic properties of the platinum compound and/or prevented the cytoprotective effects of PARP inhibition. Our results suggest that, at therapeutically relevant concentrations, the cytotoxicity of the platinum compound dominated over that of the PARP inhibitor and the PI3K inhibitor, even though a regression-based model could have indicated an overall synergy at lower and/or higher concentrations.

Prenylated flavonoids from Ficus hirta induces HeLa cells apoptosis via MAPK and AKT signaling pathways

A pair of undescribed enantiomers, (±) ficusflavonid A (1a/1b), along with five known analogues, were isolated from the roots of Ficus hirta. Their structures were determined by the analysis of extensive spectroscopic data (including UV, IR, HRESIMS and NMR). Two enantiomers (1a and 1b) were successfully separated by chiral chromatographic column and their absolute configurations were assigned by the comparison of experimental and calculated ECD data. The cytotoxicity of all the isolates against HeLa, MCF-7, HepG2 and H460 cell lines were evaluated by MTT assay. Among them, 4 suppressed the proliferation of HeLa cells with the IC₅₀ value of 28.88 μM. Furthermore, the apoptotic effect of 4 on HeLa cells and the level of several crucial proteins in AKT/MAPKs signaling pathways were analyzed by flow cytometer and western blot assay. As a result, 4 induced HeLa cell apoptosis in a dose dependent manner and significantly increased the protein levels of p-JNK and p-p38, whereas distinctly reduced the expression of p-AKT, and p-ERK. Thus, compound 4 might induce HeLa cells apoptosis via MAPK and AKT signaling pathways, which could be considered as a potential leading compound for the development of anticancer drugs.

Attenuating PI3K/Akt- mTOR pathway reduces dihydrosphingosine 1 phosphate mediated collagen synthesis and hypertrophy in primary cardiac cells

Cardiac fibrosis and myocyte hypertrophy play contributory roles in the progression of diseases such as heart Failure (HF) through what is collectively termed cardiac remodelling. The phosphoinositide 3- kinase (PI3K), protein kinase B (Akt) and mammalian target for rapamycin (mTOR) signalling pathway (PI3K/Akt- mTOR) is an important pathway in protein synthesis, cell growth, cell proliferation, and lipid metabolism. The sphingolipid, dihydrosphingosine 1 phosphate (dhS1P) has been shown to bind to high density lipids in plasma. Unlike its analog, spingosine 1 phosphate (S1P), the role of dhS1P in cardiac fibrosis is still being deciphered. This study was conducted to investigate the effect of dhS1P on PI3K/Akt signalling in primary cardiac fibroblasts and myocytes. Our findings demonstrate that inhibiting PI3K reduced collagen synthesis in neonatal cardiac fibroblasts (NCFs), and hypertrophy in neonatal cardiac myocytes (NCMs) induced by dhS1P, in vitro. Reduced activation of the PI3K/Akt- mTOR signalling pathway led to impaired translation of fibrotic proteins such as collagen 1 (Coll1) and transforming growth factor β (TGFβ) and inhibited the transcription and translation of tissue inhibitor of matrix metalloproteinase 1 (TIMP1). PI3K inhibition also affected the gene expression of S1P receptors and enzymes such as the dihydroceramide delta 4 desaturase (DEGS1) and sphingosine kinase 1 (SK1) in the de novo sphingolipid pathway. While in myocytes, PI3K inhibition reduced myocyte hypertrophy induced by dhS1P by reducing skeletal muscle α- actin (αSKA) mRNA expression, and protein translation due to increased glycogen synthase kinase 3β (GSK3β) mRNA expression. Our findings show a relationship between the PI3K/Akt- mTOR signalling cascade and exogenous dhS1P induced collagen synthesis and myocyte hypertrophy in primary neonatal cardiac cells.

AKT1-CREB stimulation of PDGFRα expression is pivotal for PTEN deficient tumor development

As evidenced by the behavior of loss-of-function mutants of PTEN in the context of a gain-of-function mutation of AKT1, the PTEN-AKT1 signaling pathway plays a critical role in human cancers. In this study, we demonstrated that a deficiency in PTEN or activation of AKT1 potentiated the expression of platelet-derived growth factor receptor α (PDGFRα) based on studies on Pten-/- mouse embryonic fibroblasts, human cancer cell lines, the hepatic tissues of Pten conditional knockout mice, and human cancer tissues. Loss of PTEN enhanced PDGFRα expression via activation of the AKT1-CREB signaling cascade. CREB transactivated PDGFRα expression by direct binding of the promoter of the PDGFRα gene. Depletion of PDGFRα attenuated the tumorigenicity of Pten-null cells in nude mice. Moreover, the PI3K-AKT signaling pathway has been shown to positively correlate with PDGFRα expression in multiple cancers. Augmented PDGFRα was associated with poor survival of cancer patients. Lastly, combination treatment with the AKT inhibitor MK-2206 and the PDGFR inhibitor CP-673451 displayed synergistic anti-tumor effects. Therefore, activation of the AKT1-CREB-PDGFRα signaling pathway contributes to the tumor growth induced by PTEN deficiency and should be targeted for cancer treatment.

The Role of mTOR Signaling as a Therapeutic Target in Cancer

The aim of this review was to summarize current available information about the role of phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling in cancer as a potential target for new therapy options. The mTOR and PI3K/AKT/mTORC1 (mTOR complex 1) signaling are critical for the regulation of many fundamental cell processes including protein synthesis, cell growth, metabolism, survival, catabolism, and autophagy, and deregulated mTOR signaling is implicated in cancer, metabolic dysregulation, and the aging process. In this review, we summarize the information about the structure and function of the mTOR pathway and discuss the mechanisms of its deregulation in human cancers including genetic alterations of PI3K/AKT/mTOR pathway components. We also present recent data regarding the PI3K/AKT/mTOR inhibitors in clinical studies and the treatment of cancer, as well the attendant problems of resistance and adverse effects.

Juglone prevents human platelet aggregation through inhibiting Akt and protein disulfide isomerase

BACKGROUND/PURPOSE

Juglone, a natural compound widely found in Juglandaceae plants, has been suggested as a potential drug candidate for treating cancer, inflammation, and diabetic vascular complications. In the present study, the antiplatelet effect and underlying mechanisms of juglone were investigated for the first time.

STUDY DESIGN/METHODS

Human platelet aggregation and activation were measured by turbidimetric aggregometry, flow cytometry, and Western blotting. In vitro antithrombotic activity of juglone was assessed using collagen-coated flow chambers under whole-blood flow conditions. The effect of juglone on protein disulfide isomerase (PDI) activity was determined by the dieosin glutathione disulfide assay.

RESULTS

Juglone (1 - 5 μM) inhibited platelet aggregation and glycoprotein (GP) IIb/IIIa activation caused by various agonists. In a whole blood flow chamber system, juglone reduced thrombus formation on collagen-coated surfaces under arterial shear rates. Juglone abolished intracellular Ca²⁺ elevation and protein kinase C activation caused by collagen, but had no significant effect on that induced by G protein-coupled receptor agonists. In contrast, Akt activation caused by various agonists were inhibited in juglone-treated platelets. Additionally, juglone showed inhibitory effects on both recombinant human PDI and platelet surface PDI at concentrations similar to those needed to prevent platelet aggregation.

CONCLUSION

Juglone exhibits potent in vitro antiplatelet and antithrombotic effects that are associated with inhibition of Akt activation and platelet surface PDI activity.

Piperlongumine attenuates angiotensin-II-induced cardiac hypertrophy and fibrosis by inhibiting Akt-FoxO1 signalling

BACKGROUND

Cardiac hypertrophy and fibrosis are closely related to cardiac dysfunction, especially diastolic dysfunction. Limited medications can be used to simultaneously delay cardiac hypertrophy and fibrosis in clinical practice. Piperlongumine (PLG) is an amide alkaloid extracted from Piper longum and has been shown to have multiple biological effects, including anticancer and antioxidant effects. However, the role of PLG in cardiac hypertrophy and fibrosis is not clear.

PURPOSE

The aim of this study was to reveal the role of PLG in cardiac hypertrophy and fibrosis and the associated mechanism.

METHODS

Cardiac hypertrophy and fibrosis were induced by angiotensin II (Ang II) in vivo and in vitro. The effect of PLG in vivo, in vitro and its mechanism were investigated by proliferation and apoptosis assays, western blot, real-time PCR, immunofluorescence, histochemistry, echocardiography, flow cytometry and chromatin immunoprecipitation.

RESULTS

Proliferation and apoptosis assays showed that 2.5 μM PLG slightly inhibited proliferation and did not promote apoptosis. Treatment with 5 mg/kg PLG obviously inhibited Ang II-induced cardiac hypertrophy and fibrosis in vivo. In vitro studies of neonatal rat cardiomyocytes (NRCMs) showed that the anti-hypertrophic effect of PLG was mediated by reducing the phosphorylation of Akt and thereby preserving the level of Forkhead box transcription factor O1 (FoxO1), since knockdown of FoxO1 by siRNA reversed the protective effect of PLG on NRCMs. In addition, PLG significantly decreased the Ang II-induced expression of profibrotic proteins in neonatal cardiac fibroblasts by reducing the expression of Krüppel-like factor 4 (KLF4) and the recruitment of KLF4 to the promoter regions of transforming growth factor-β and connective tissue growth factor.

CONCLUSION

We demonstrate the cardioprotective effects of PLG in both cardiac hypertrophy and fibrosis and the potential value of PLG for developing novel medications for pathological cardiac hypertrophy and heart failure.

Rosmarinic Acid Regulates Microglial M1/M2 Polarization via the PDPK1/Akt/HIF Pathway Under Conditions of Neuroinflammation

Microglia are resident macrophage-like cells in the central nervous system (CNS). The induction of microglial activation dampens neuroinflammation-related diseases by promoting microglial (re)polarization to the anti-inflammatory (M2) phenotype and can serve as a potential therapeutic approach. Mitochondrial respiration and metabolic reprogramming are required for the anti-inflammatory response of M2 macrophages. However, whether these mitochondrial-dependent pathways are involved in microglial (re)polarization to the anti-inflammatory (M2) phenotype under conditions of lipopolysaccharide (LPS)-induced neuroinflammation remains unclear. Moreover, the mechanisms that coordinate mitochondrial respiration and the functional reprogramming of microglial cells have not been fully elucidated. Rosmarinic acid (RA) possesses antioxidative and anti-inflammatory activities, and we previously reported that RA markedly suppresses LPS-stimulated M1 microglial activation in mice. In this study, we found that RA suppresses M1 microglial polarization and promotes microglial polarization to the M2 phenotype under conditions of neuroinflammation. We identified an increase in mitochondrial respiration and found that metabolic reprogramming is required for the RA-mediated promotion of microglial polarization to the M2 phenotype under LPS-induced neuroinflammation conditions. Hypoxia-inducible factor (HIF) subunits are the key effector molecules responsible for the effects of RA on the restoration of mitochondrial function, metabolic reprogramming, and phenotypic polarization to M2 microglia. The phosphoinositide-dependent protein kinase 1 (PDPK1)/Akt/mTOR pathway is involved in the RA-mediated regulation of HIF expression and increase in M2 marker expression. We propose that the inhibition of PDPK1/Akt/HIFs by RA might be a potential therapeutic approach for inhibiting neuroinflammation through the regulation of microglial M1/M2 polarization. Graphical abstract Schematic of the mechanism through which RA suppresses LPS-induced neuroinflammation by promoting microglial polarization to the M2 phenotype via PDPK1/Akt/HIFs. The bold arrows indicate the direction of the effects of RA (i.e., inhibitory or promoting effects on cytokines or mediators).

An acetyl-histone vulnerability in PI3K/AKT inhibition-resistant cancers is targetable by both BET and HDAC inhibitors

Acquisition of resistance to phosphatidylinositol 3-kinase (PI3K)/AKT-targeted monotherapy implies the existence of common resistance mechanisms independent of cancer type. Here, we demonstrate that PI3K/AKT inhibitors cause glycolytic crisis, acetyl-coenzyme A (CoA) shortage, and a global decrease in histone acetylation. In addition, PI3K/AKT inhibitors induce drug resistance by selectively augmenting histone H3 lysine 27 acetylation (H3K27ac) and binding of CBP/p300 and BRD4 proteins at a subset of growth factor and receptor (GF/R) gene loci. BRD4 occupation at these loci and drug-resistant cell growth are vulnerable to both bromodomain and histone deacetylase (HDAC) inhibitors. Little or no occupation of HDAC proteins at the GF/R gene loci underscores the paradox that cells respond equivalently to the two classes of inhibitors with opposite modes of action. Targeting this unique acetyl-histone-related vulnerability offers two clinically viable strategies to overcome PI3K/AKT inhibitor resistance in different cancers.

Pan-AKT Inhibitor Capivasertib With Docetaxel and Prednisolone in Metastatic Castration-Resistant Prostate Cancer: A Randomized, Placebo-Controlled Phase II Trial (ProCAID)

PURPOSE

Capivasertib is a pan-AKT inhibitor. Preclinical data indicate activity in metastatic castration-resistant prostate cancer (mCRPC) and synergism with docetaxel.

PATIENTS AND METHODS

ProCAID was a placebo controlled randomized phase II trial in mCRPC. Patients received up to ten 21-day cycles of docetaxel (75 mg/m2 intravenous, day 1) and prednisolone (5 mg twice daily, oral, day 1-21) and were randomly assigned (1:1) to oral capivasertib (320 mg twice daily, 4 days on/3 days off, from day 2 each cycle), or placebo, until disease progression. Treatment allocation used minimization factors: bone metastases; visceral metastases; investigational site; and prior abiraterone or enzalutamide. The primary objective, by intention to treat, determined if the addition of capivasertib prolonged a composite progression-free survival (cPFS) end point that included prostate-specific antigen progression events. cPFS and overall survival (OS) were also assessed by composite biomarker subgroup for PI3K/AKT/PTEN pathway activation status.

RESULTS

One hundred and fifty patients were enrolled. Median cPFS was 7.03 (95% CI, 6.28 to 8.25) and 6.70 months (95% CI, 5.52 to 7.36) with capivasertib and placebo respectively (hazard ratio [HR], 0.92; 80% CI, 0.73 to 1.16; one-sided P = .32). Median OS was 31.15 (95% CI, 20.07 to not reached) and 20.27 months (95% CI, 17.51 to 24.18), respectively (HR, 0.54; 95% CI, 0.34 to 0.88; two-sided P = .01). cPFS and OS results were consistent irrespective of PI3K/AKT/PTEN pathway activation status. Grade III-IV adverse events were equivalent between arms (62.2%). The most common adverse events of any grade deemed related to capivasertib were diarrhea, fatigue, nausea, and rash.

CONCLUSION

The addition of capivasertib to chemotherapy did not extend cPFS in mCRPC irrespective of PI3K/AKT/PTEN pathway activation status. The observed OS result (a secondary end point) will require prospective validation in future studies to address potential for bias.

Salvia miltiorrhiza stems and leaves total phenolic acids combination with tanshinone protect against DSS-induced ulcerative colitis through inhibiting TLR4/PI3K/AKT/mTOR signaling pathway in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bge. as a traditional Asian medicinal plant, roots and rhizomes (Danshen) are used to treat chronic hepatitis and coronary heart disease. In recent years, the medicinal value of S. miltiorrhiza stems and leaves total phenolic acids extract (JF) similar to roots and rhizomes has received increasing attention. S. miltiorrhiza roots and rhizome tanshinone extract (DT) has a good anti-inflammatory effect.

AIM OF THE STUDY

To explore the therapeutic effect and possible molecular mechanisms of JF and DT alone or in combination on dextran sulfate sodium (DSS)-induced colitis mice.

MATERIALS AND METHODS

Colitis was induced by received 2% DSS in drinking water for 7 consecutive days. Then mice were administered orally for 7 days. Disease activity index (DAI) scores and body weight were recorded daily. After the end of the experiment, colon was removed, colon length was measured and histopathological analysis was performed. Inflammatory factors expression was determined by ELISA, its mRNA expression was detected by real-time quantitative PCR, and the expression of related proteins on TLR4/PI3K/AKT/mTOR signal was analyzed by Western blot.

RESULTS

Treatment with JF and DT alone or in combination reduced DAI scores, increase body weight, improved colon shortening, and decreased colon histology scores. In addition, the expression level of inflammatory factors was inhibited. The combination of JF and DT had a better inhibitory effect on inflammatory factors compared to JF alone. We also found that DT alone and JF combined with DT inhibited TLR4/PI3K/AKT/mTOR signaling-related proteins expression levels (including TLR4, p-PI3K p110α/PI3K p110α, p-AKT (ser473)/AKT, mTOR, p-mTOR, NF-κB p65), showing an effective anti-inflammatory effect.

CONCLUSIONS

We demonstrated for the first time that, JF and DT alone or in combination effectively ameliorated DSS-induced ulcerative colitis in mice, possibly by inhibiting the TLR4/PI3K/AKT/mTOR signaling pathway.

Xiaoyaosan decoction alleviated rat liver fibrosis via the TGFβ/Smad and Akt/FoxO3 signaling pathways based on network pharmacology analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis is an outcome of many chronic liver diseases and often results in cirrhosis, liver failure, and even hepatocarcinoma. Xiaoyaosan decoction (XYS) as a classical Traditional Chinese Medicine (TCM) formula is used to liver fibrosis in clinical practice while its mechanism is unclear.

AIM OF THE STUDY

The aim of this study was to investigate the anti-fibrosis effect of XYS and to explore the molecular mechanisms by combining network pharmacology and transcriptomic technologies.

MATERIALS AND METHODS

The carbon tetrachloride (CCl4)-induced liver fibrosis rat were treated with three doses of XYS. The liver fibrosis and function were evaluated by histopathological examination and serum biochemical detection. The fibrosis related protein a-SMA and collagen I were assessed by Western blot. Different expressed genes (DEGs) between XYS-treated group and model group were analyzed. The herb-component-target network was constructed combined the network pharmacology. The predict targets and pathways were validated by in vitro and in vivo experiments.

RESULTS

With XYS treatment, the liver function was significantly improved, and fibrotic changes were alleviated. The a-SMA and collagen I expression levels in the liver were also decreased in XYS-treated rats compared with CCl4 model rats. 108 active components and 42 targets from 8 herbs constituted herb-compound-target network by transcriptomics and network pharmacology analysis. The KEGG pathway and GO enrichment analyses showed that the FoxO, TGFβ, AMPK, MAPK, PPAR, and hepatitis B and C pathways were involved in the anti-fibrosis effects of XYS. In the liver tissues, p-FoxO3a and p-Akt expression levels were significantly increased in the CCl4 model group but decreased in the XYS-treated group. The TGFβ1/Smad pathway and Akt/FoxO3 pathway were verified in LX2 cells by inhibiting phosphorylation of Smad3 and Akt activity, respectively.

CONCLUSIONS

Our findings suggested that XYS markedly alleviated CCl4-induced liver fibrosis in histopathological and serum liver function analyses, and this effect may occur via the TGFβ1/Smad and Akt/FoxO signaling pathways.

CK2 Down-Regulation Increases the Expression of Senescence-Associated Secretory Phenotype Factors through NF-κB Activation

Senescent cells secrete pro-inflammatory factors, and a hallmark feature of senescence is senescence-associated secretory phenotype (SASP). The aim of this study is to investigate the protein kinase CK2 (CK2) effects on SASP factors expression in cellular senescence and organism aging. Here CK2 down-regulation induced the expression of SASP factors, including interleukin (IL)-1β, IL-6, and matrix metalloproteinase (MMP) 3, through the activation of nuclear factor-κB (NF-κB) signaling in MCF-7 and HCT116 cells. CK2 down-regulation-mediated SIRT1 inactivation promoted the degradation of inhibitors of NF-κB (IκB) by activating the AKT-IκB kinase (IKK) axis and increased the acetylation of lysine 310 on RelA/p65, an important site for the activity of NF-κB. kin-10 (the ortholog of CK2β) knockdown increased zmp-1, -2, and -3 (the orthologs of MMP) expression in nematodes, but AKT inhibitor triciribine and SIRT activator resveratrol significantly abrogated the increased expression of these genes. Finally, antisense inhibitors of miR-186, miR-216b, miR-337-3p, and miR-760 suppressed CK2α down-regulation, activation of the AKT-IKK-NF-κB axis, RelA/p65 acetylation, and expression of SASP genes in cells treated with lipopolysaccharide. Therefore, this study indicated that CK2 down-regulation induces the expression of SASP factors through NF-κB activation, which is mediated by both activation of the SIRT1-AKT-IKK axis and RelA/p65 acetylation, suggesting that the mixture of the four miRNA inhibitors can be used as anti-inflammatory agents.

Interleukin-22 regulating Kupffer cell polarization through STAT3/Erk/Akt crosstalk pathways to extenuate liver fibrosis

AIMS

Interleukin (IL)-22 activates multiple signaling pathways to exert anti-inflammatory effects, but few studies have examined whether and how IL-22 may shift macrophage polarization between M1 (pro-inflammatory) and M2 (anti-inflammatory) states and thereby influence the progression of hepatic fibrosis.

MAIN METHODS

Utilized CCl4 to induce liver fibrosis in mice, detected the role of IL-22 in inhibiting liver fibrosis by regulating Kupffer cells (KCs) polarization in vivo and in vitro. U937 cells were used to confirm the mechanism of IL-22 regulating macrophage polarization via the STAT3/Erk/Akt pathways. Human liver specimens were collected to verify the correlation between the levels of IL-22 and KCs during liver fibrogenesis.

KEY FINDINGS

During CCl4-induced liver fibrosis progression in mice, adding exogenous IL-22 significantly inhibited pro-fibrogenic and macrophage phenotype-altering factors secreted by M1-KCs, and it increased the number of M2-KCs. In co-cultures of hepatic stellate cells and KCs from mice treated with IL-22, a high M2/M1-KCs ratio inhibited collagen production and stellate cell activation. These results suggest that IL-22 can increase the ratio of M2-KCs to M1-KCs and thereby attenuate the progression of liver fibrosis. Mechanistic studies in vitro showed that IL-22 promoted polarization of lipopolysaccharide-treated U937 macrophages from M1 to M2. The cytokine exerted these effects by activating the STAT3 pathway while suppressing Erk1/2 and Akt pathways. Furthermore, immunofluorescent staining in human liver specimens confirmed that IL-22 levels positively correlated with the number of M2-KCs during liver fibrogenesis.

SIGNIFICANCE

IL-22 regulates the STAT3/Erk/Akt to increase the M2/M1-KCs ratio and thereby slow liver fibrogenesis.

PI3K/AKT/mTOR Signaling Pathway in Breast Cancer: From Molecular Landscape to Clinical Aspects

Breast cancer is a serious health problem worldwide, representing the second cause of death through malignancies among women in developed countries. Population, endogenous and exogenous hormones, and physiological, genetic and breast-related factors are involved in breast cancer pathogenesis. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) is a signaling pathway involved in cell proliferation, survival, invasion, migration, apoptosis, glucose metabolism and DNA repair. In breast tumors, PIK3CA somatic mutations have been reported, located in exon 9 and exon 20. Up to 40% of PIK3CA mutations are estrogen receptor (ER) positive and human epidermal growth factor receptor 2 (HER2) -negative in primary and metastatic breast cancer. HER2 is overexpressed in 20-30% of breast cancers. HER1, HER2, HER3 and HER4 are membrane receptor tyrosine kinases involved in HER signaling to which various ligands can be attached, leading to PI3K/AKT activation. Currently, clinical studies evaluate inhibitors of the PI3K/AKT/mTOR axis. The main purpose of this review is to present general aspects of breast cancer, the components of the AKT signaling pathway, the factors that activate this protein kinase B, PI3K/AKT-breast cancer mutations, PI3K/AKT/mTOR-inhibitors, and the relationship between everolimus, temsirolimus and endocrine therapy.

PDE5 inhibition rescues mitochondrial dysfunction and angiogenic responses induced by Akt3 inhibition by promotion of PRC expression

Akt3 regulates mitochondrial content in endothelial cells through the inhibition of PGC-1α nuclear localization and is also required for angiogenesis. However, whether there is a direct link between mitochondrial function and angiogenesis is unknown. Here we show that Akt3 depletion in primary endothelial cells results in decreased uncoupled oxygen consumption, increased fission, decreased membrane potential, and increased expression of the mitochondria-specific protein chaperones, HSP60 and HSP10, suggesting that Akt3 is required for mitochondrial homeostasis. Direct inhibition of mitochondrial homeostasis by the model oxidant paraquat results in decreased angiogenesis, showing a direct link between angiogenesis and mitochondrial function. Next, in exploring functional links to PGC-1α, the master regulator of mitochondrial biogenesis, we searched for compounds that induce this process. We found that, sildenafil, a phosphodiesterase 5 inhibitor, induced mitochondrial biogenesis as measured by increased uncoupled oxygen consumption, mitochondrial DNA content, and voltage-dependent anion channel protein expression. Sildenafil rescued the effects on mitochondria by Akt3 depletion or pharmacological inhibition and promoted angiogenesis, further supporting that mitochondrial homeostasis is required for angiogenesis. Sildenafil also induces the expression of PGC-1 family member PRC and can compensate for PGC-1α activity during mitochondrial stress by an Akt3-independent mechanism. The induction of PRC by sildenafil depends upon cAMP and the transcription factor CREB. Thus, PRC can functionally substitute during Akt3 depletion for absent PGC-1α activity to restore mitochondrial homeostasis and promote angiogenesis. These findings show that mitochondrial homeostasis as controlled by the PGC family of transcriptional activators is required for angiogenic responses.

REDD1 Is Involved in Amyloid β-Induced Synaptic Dysfunction and Memory Impairment

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by neurological dysfunction, including memory impairment, attributed to the accumulation of amyloid β (Aβ) in the brain. Although several studies reported possible mechanisms involved in Aβ pathology, much remains unknown. Previous findings suggested that a protein regulated in development and DNA damage response 1 (REDD1), a stress-coping regulator, is an Aβ-responsive gene involved in Aβ cytotoxicity. However, we still do not know how Aβ increases the level of REDD1 and whether REDD1 mediates Aβ-induced synaptic dysfunction. To elucidate this, we examined the effect of Aβ on REDD1-expression using acute hippocampal slices from mice, and the effect of REDD1 short hairpin RNA (shRNA) on Aβ-induced synaptic dysfunction. Lastly, we observed the effect of REDD1 shRNA on memory deficit in an AD-like mouse model. Through the experiments, we found that Aβ-incubated acute hippocampal slices showed increased REDD1 levels. Moreover, Aβ injection into the lateral ventricle increased REDD1 levels in the hippocampus. Anisomycin, but not actinomycin D, blocked Aβ-induced increase in REDD1 levels in the acute hippocampal slices, suggesting that Aβ may increase REDD1 translation rather than transcription. Aβ activated Fyn/ERK/S6 cascade, and inhibitors for Fyn/ERK/S6 or mGluR5 blocked Aβ-induced REDD1 upregulation. REDD1 inducer, a transcriptional activator, and Aβ blocked synaptic plasticity in the acute hippocampal slices. REDD1 inducer inhibited mTOR/Akt signaling. REDD1 shRNA blocked Aβ-induced synaptic deficits. REDD1 shRNA also blocked Aβ-induced memory deficits in passive-avoidance and object-recognition tests. Collectively, these results demonstrate that REDD1 participates in Aβ pathology and could be a target for AD therapy.

Integrin and autocrine IGF2 pathways control fasting insulin secretion in β-cells

Elevated levels of fasting insulin release and insufficient glucose-stimulated insulin secretion (GSIS) are hallmarks of diabetes. Studies have established cross-talk between integrin signaling and insulin activity, but more details of how integrin-dependent signaling impacts the pathophysiology of diabetes are needed. Here, we dissected integrin-dependent signaling pathways involved in the regulation of insulin secretion in β-cells and studied their link to the still debated autocrine regulation of insulin secretion by insulin/insulin-like growth factor (IGF) 2-AKT signaling. We observed for the first time a cooperation between different AKT isoforms and focal adhesion kinase (FAK)-dependent adhesion signaling, which either controlled GSIS or prevented insulin secretion under fasting conditions. Indeed, β-cells form integrin-containing adhesions, which provide anchorage to the pancreatic extracellular matrix and are the origin of intracellular signaling via FAK and paxillin. Under low-glucose conditions, β-cells adopt a starved adhesion phenotype consisting of actin stress fibers and large peripheral focal adhesion. In contrast, glucose stimulation induces cell spreading, actin remodeling, and point-like adhesions that contain phospho-FAK and phosphopaxillin, located in small protrusions. Rat primary β-cells and mouse insulinomas showed an adhesion remodeling during GSIS resulting from autocrine insulin/IGF2 and AKT1 signaling. However, under starving conditions, the maintenance of stress fibers and the large adhesion phenotype required autocrine IGF2-IGF1 receptor signaling mediated by AKT2 and elevated FAK-kinase activity and ROCK-RhoA levels but low levels of paxillin phosphorylation. This starved adhesion phenotype prevented excessive insulin granule release to maintain low insulin secretion during fasting. Thus, deregulation of the IGF2 and adhesion-mediated signaling may explain dysfunctions observed in diabetes.

Implication of integrins α3β1 and α5β1 in invasion and anoikis of SK-Mel-147 human melanoma cells: non-canonical functions of protein kinase Akt

Downregulation of integrins α3β1 and α5β1 strongly decreased cell colony formation and in vitro invasion and markedly enhanced anoikis in SK-Mel-147 human melanoma cells. These modifications were accompanied by a marked increase in the levels of active Akt protein kinase, which indicated it played a non-canonical function in the melanoma cells. Pharmacological inhibition of Akt1, an Akt isozyme, in cells depleted of α3β1 or α5β1 restored their invasive activity, while inhibition of the Akt 2 isoform did not cause a visible effect. Similar to our previous results with the α2β1 integrin, this finding suggested that in signaling pathways initiated by α3β1 and α5β1, the Akt1 isoform performs a non-canonical function in regulating invasive phenotype of melanoma cells. In contrast, when the effects of Akt inhibitors on anoikis of the melanoma cells were compared, the Akt2 isoform demonstrated a non-canonical activity in which Akt2 suppression led to a significant attenuation of apoptosis in cells with downregulated α3β1 or α5β1. Our results were the first evidence that, in the same tumor cells, different integrins can control various manifestations of tumor progression through distinct signaling pathways that are both common to various integrins and specific to a particular receptor.

Geraniol ameliorates diabetic nephropathy via interference with miRNA-21/PTEN/Akt/mTORC1 pathway in rats

Deregulated activity of protein kinase B/mammalian target of rapamycin complex-1 (Akt/mTORC1) incites crucial pathological characteristics of diabetic nephropathy. The acyclic monoterpene geraniol has been recently reported to possess antidiabetic effects; however, its potential renoprotective effect in diabetes has not yet been elucidated. This study aimed to assess the possible modulatory effect of geraniol on the Akt/mTORC1 pathway in diabetes-induced nephropathy in rats compared to the standard antidiabetic drug gliclazide. Geraniol and gliclazide was administered daily to diabetic rats for 6 weeks starting on the 3rd-day post diabetes induction by streptozotocin (STZ). Geraniol amended the deteriorated renal function (serum creatinine; blood urea nitrogen). It exerted a remarkable antihyperglycemic effect that is comparable to that of gliclazide and suppressed the fibrotic marker, transforming growth factor-β. Geraniol restored redox balance and inhibited lipid peroxidation by reducing nicotine amide adenine dinucleotide phosphate oxidase and enhancing the antioxidant enzyme, superoxide dismutase. These beneficial effects were associated with a robust downregulation of miRNA-21 and consequently, reversion of tumor suppressor protein phosphatase and tension homolog (PTEN)/Akt/mTORC1 cue and its downstream proteins required for mesangial cell proliferation and matrix protein synthesis. The current study indicates that geraniol interfered with miRNA-21/ PTEN/AKT/mTORC1 pathway signaling that contributes largely to the progression of mesangial expansion and extracellular matrix deposition in diabetic nephropathy.

Dingkun Pill replenishes diminished ovarian reserve through the PI3K/AKT/mTOR signaling pathway in TWP-induced mice

ETHNOPHARMACOLOGICAL RELEVANCE

Diminished ovarian reserve (DOR) can lead to poor fertility and shorten the reproductive lifespan of females. The Dingkun Pill (DKP), a traditional Chinese-patented medication, has been an integral part of traditional Chinese medicinal treatment for the management of gynecological diseases for centuries. Relevant clinical studies have shown that DKP is able to protect against DOR, however, its mechanism of action is not yet fully elucidated.

STUDY GOALS

This study was conducted with the aim of exploring the impact of tripterygium wilfordii polyglycosidium (TWP) on the PI3K/AKT/mTOR pathway in the context of the pathophysiology of DOR and the mechanism of action of DKP.

MATERIALS AND METHODS

Eighty female balb/c mice with regular estrous cycles were assigned to Blank, Model, DKP and hormone replacement therapy (HRT) groups in a random manner. With the exception of the Blank group, mice in the other groups were exposed to 40 mg/kg/d TWP suspension for 30 days to DOR induction. Following this, either DKP or hormones were orally administrated to determine their effect on disease progression. During the experiment, changes in body weight and the estrous cycles of the mice were observed. Post treatment, serum sample anti-mullerian hormone (AMH), estradiol (E₂), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were quantified using enzyme-linked immunosorbent assay (ELISA). The mice were then sacrificed in order to harvest their ovaries for hematoxylin and eosin (HE) staining. This process allowed for the assessment of ovarian morphology and follicular quantification. Apoptotic ovarian cells of the ovary were assessed using TUNEL technique, while Caspase-3 and Cytochrome C (Cyt C) expressions of the ovary were examined through immunohistochemistry (IHC). Western blotting analysis was used to quantify levels of Bax, Bcl-2, Caspase-3, Cyt C, mTOR, P-mTOR, AKT, P-AKT, P-PI3K and PI3K proteins, while mRNA levels of Bax, Bcl-2, PI3K, AKT and mTOR were measured in ovarian tissue using RT-PCR.

RESULTS

The findings revealed that DKP was able to improve levels of serum hormones and promote the recovery of the estrous cycle. DKP augmented the total amount of primordial follicles while reducing the number of follicles that were atretic follicles. The apoptosis index of growing follicles and Bax, Cyt C and Caspase-3 expressions decreased, while the Bcl-2: Bax ratio increased. DKP suppressed levels of phosphorylation and the mRNA expressions of mTOR, AKT and PI3K.

CONCLUSIONS

It was demonstrated that DKP was able to increase ovarian reserves through inhibition of the PI3K/AKT/mTOR signaling pathway, which lead to the suppression of primordial follicle activity and a reduction in levels of apoptosis of early growing follicles. This highlights its potentially beneficial role for the treatment of DOR.

Study on the regulatory mechanism and experimental verification of icariin for the treatment of ovarian cancer based on network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Herba Epimedii (Berberidaceae) has the advantages of "nourishing the kidney and reinforcing the Yang". Many species in this genus have long been used in traditional Chinese medicine (TCM) and have been used as anticancer drugs in traditional Chinese herbal medicine formulations. Icariin, a major flavonoid glycoside extracted from Epimedium brevicornum Maxim, has been widely proven to exert an inhibitory effect on ovarian cancer (OC), and icariin can induce apoptosis and inhibit invasion and migration. However, the underlying mechanism remains unclear, so further research is necessary to verify its traditional use.

AIM OF THE STUDY

This study aimed to explore the regulatory mechanism of icariin in the biological network and signalling pathway of OC through network pharmacology and cytological experiments.

METHODS

Public databases and R × 3.6.2 software were adopted to predict the potential targets, construct the protein-protein interaction (PPI) network, and perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. After the network pharmacological analysis, cytological experiments, real-time quantitative PCR (qPCR) and Western blot (WB) analyses were used to verify the key signalling pathway.

RESULTS

The targets related to treatment were TNF, MMP9, STAT3, PIK3CA, ERBB2, MTOR, IL2, PTGS2, KDR, and F2. GO and KEGG enrichment analyses indicated that various kinases and the PI3K/AKT signalling pathway were the most enriched molecules and pathways. Icariin inhibited OC SKOV3 cell proliferation, migration and invasion in vitro and promoted apoptosis by inhibiting the PI3K/AKT signalling pathway.

CONCLUSION

Icariin promotes apoptosis and suppresses SKOV3 cell activities through the PI3K-Akt signalling pathway. This research not only provides a theoretical and experimental basis for more in-depth studies but also offers an efficient method for the rational utilization of a series of icariin flavonoids as anti-tumour drugs.

Combined treatment of mitoxantrone sensitizes breast cancer cells to rapalogs through blocking eEF-2K-mediated activation of Akt and autophagy

Oncogenic activation of the mTOR signaling pathway occurs frequently in tumor cells and contributes to the devastating features of cancer, including breast cancer. mTOR inhibitors rapalogs are promising anticancer agents in clinical trials; however, rapalogs resistance remains an unresolved clinical challenge. Therefore, understanding the mechanisms by which cells become resistant to rapalogs may guide the development of successful mTOR-targeted cancer therapy. In this study, we found that eEF-2K, which is overexpressed in cancer cells and is required for survival of stressed cells, was involved in the negative-feedback activation of Akt and cytoprotective autophagy induction in breast cancer cells in response to mTOR inhibitors. Therefore, disruption of eEF-2K simultaneously abrogates the two critical resistance signaling pathways, sensitizing breast cancer cells to rapalogs. Importantly, we identified mitoxantrone, an admitted anticancer drug for a wide range of tumors, as a potential inhibitor of eEF-2K via a structure-based virtual screening strategy. We further demonstrated that mitoxantrone binds to eEF-2K and inhibits its activity, and the combination treatment of mitoxantrone and mTOR inhibitor resulted in significant synergistic cytotoxicity in breast cancer. In conclusion, we report that eEF-2K contributes to the activation of resistance signaling pathways of mTOR inhibitor, suggesting a novel strategy to enhance mTOR-targeted cancer therapy through combining mitoxantrone, an eEF-2K inhibitor.

Cinnamaldehyde Inhibits the Function of Osteosarcoma by Suppressing the Wnt/β-Catenin and PI3K/Akt Signaling Pathways

BACKGROUND

Osteosarcoma (OS) is a primary bone tumor associated with locally aggressive growth and early metastatic potential that typically occurs in children and adolescents. Chinese traditional medicine Cinnamomum cassia Presl has been shown to have significant tumor-killing effect, in which cinnamaldehyde (CA) is the main active ingredient.

PURPOSE

To explore the anticancer effect of CA on the osteosarcoma cells and the possible molecular mechanism.

METHODS

Crystal violet assay, MTT assay and colony-forming assay were used to confirm the inhibitory role of CA in the proliferation of 143B and MG63 osteosarcoma cells. Hoechst 33258 staining and flow cytometry were used to observe apoptosis. The migration and invasion role of OS cells were evaluated using transwell assays and wound healing assays. Western blotting was used to analyse the protein expression levels. Nude mice were inoculated with 143B cells to establish an orthotopic OS tumor animal model and to investigate the effects of CA on OS tumors.

RESULTS

According to crystal violet assay, MTT assay and colony-forming assay, CA significantly inhibited cell proliferation. Hoechst 33258 staining and flow cytometry analysis showed that CA-induced apoptosis in a concentration-dependent manner. In addition, transwell assays and wound healing assays showed that CA inhibited the migration and invasion of osteosarcoma cells. In vivo mouse models, CA inhibited the growth of osteosarcoma. The potential mechanisms could be that CA inhibited the transcriptional activity of Wnt/β-catenin and PI3K/Akt of the osteosarcoma.

CONCLUSION

CA may inhibit the proliferation, migration, invasion and promote apoptosis of OS cells by inhibiting Wnt/β-catenin and PI3K/Akt signaling pathways. CA may be a potentially effective anti-tumor drug.

The protective role of corilagin on renal calcium oxalate crystal-induced oxidative stress, inflammatory response, and apoptosis via PPAR-γ and PI3K/Akt pathway in rats

Kidney stones, also known as calcium oxalate (CaOx) nephrolithiasis, are often asymptomatic, leading to kidney injury and renal failure complications. Corilagin is a gallotannin found in various plants and is known to elicit various biological activities. The present study aimed to elucidate the renoprotective effect of corilagin against the rats' renal stones deposition. The rats were induced for nephrolithiasis (CaOx deposition) using 0.75% ethylene glycol in their drinking water. Then, they were treated with corilagin at 50 and 100 mg/kg/day for 4 weeks. At the end of the experimental period, the rats were killed; blood and renal tissues were collected for various histological, biochemical, and gene expression analyses. The results demonstrated that the rats had renal calculi displaying a significant increase in serum creatinine (59.39 μmol/L) and blood urea nitrogen (19.03 mmol/L) levels compared with controls. Moreover, the malondialdehyde (13.29 nmol/mg) level was found to increase with a profound reduction in antioxidants' activities with upregulated inflammatory cytokines. In contrast, the RT-PCR and immunohistochemistry analysis demonstrated a substantial reduction in cell survival markers PPAR-γ and PI3K/Akt with an apparent increase in apoptosis markers genes expressions in rats suffering from renal stones. Thus, the present study results suggest that corilagin could suppress renal CaOx crystal-induced oxidative stress, inflammatory response, and apoptosis via PPAR-γ and PI3K/Akt-mediated pathway.

Inhibitory Effect of a Human MicroRNA, miR-6133-5p, on the Fibrotic Activity of Hepatic Stellate Cells in Culture

BACKGROUND

We recently identified 39 human microRNAs, which effectively suppress hepatitis B virus (HBV) replication in hepatocytes. Chronic HBV infection often results in active, hepatitis-related liver fibrosis; hence, we assessed whether any of these microRNAs have anti-fibrotic potential and predicted that miR-6133-5p may target several fibrosis-related genes.

METHODS

The hepatic stellate cell line LX-2 was transfected with an miR-6133-5p mimic and subsequently treated with Transforming growth factor (TGF)-β. The mRNA and protein products of the COL1A1 gene, encoding collagen, and the ACTA2 gene, an activation marker of hepatic stellate cells, were quantified.

RESULTS

The expression of COL1A1 and ACTA2 was markedly reduced in LX-2 cells treated with miR-6133-5p. Interestingly, phosphorylation of c-Jun N-terminal kinase (JNK) was also significantly decreased by miR-6133-5p treatment. The expression of several predicted target genes of miR-6133-5p, including TGFBR2 (which encodes Transforming Growth Factor Beta Receptor 2) and FGFR1 (which encodes Fibroblast Growth Factor Receptor 1), was also reduced in miR-6133-5p-treated cells. The knockdown of TGFBR2 by the corresponding small interfering RNA greatly suppressed the expression of COL1A1 and ACTA2. Treatment with the JNK inhibitor, SP600125, also suppressed COL1A1 and ACTA2 expression, indicating that TGFBR2 and JNK mediate the anti-fibrotic effect of miR-6133-5p. The downregulation of FGFR1 may result in a decrease of phosphorylated Akt, ERK (extracellular signal-regulated kinase), and JNK.

CONCLUSION

miR-6133-5p has a strong anti-fibrotic effect, mediated by inactivation of TGFBR2, Akt, and JNK.

Circulating tumour DNA analysis to direct therapy in advanced breast cancer (plasmaMATCH): a multicentre, multicohort, phase 2a, platform trial

BACKGROUND

Circulating tumour DNA (ctDNA) testing might provide a current assessment of the genomic profile of advanced cancer, without the need to repeat tumour biopsy. We aimed to assess the accuracy of ctDNA testing in advanced breast cancer and the ability of ctDNA testing to select patients for mutation-directed therapy.

METHODS

We did an open-label, multicohort, phase 2a, platform trial of ctDNA testing in 18 UK hospitals. Participants were women (aged ≥18 years) with histologically confirmed advanced breast cancer and an Eastern Cooperative Oncology Group performance status 0-2. Patients had completed at least one previous line of treatment for advanced breast cancer or relapsed within 12 months of neoadjuvant or adjuvant chemotherapy. Patients were recruited into four parallel treatment cohorts matched to mutations identified in ctDNA: cohort A comprised patients with ESR1 mutations (treated with intramuscular extended-dose fulvestrant 500 mg); cohort B comprised patients with HER2 mutations (treated with oral neratinib 240 mg, and if oestrogen receptor-positive with intramuscular standard-dose fulvestrant); cohort C comprised patients with AKT1 mutations and oestrogen receptor-positive cancer (treated with oral capivasertib 400 mg plus intramuscular standard-dose fulvestrant); and cohort D comprised patients with AKT1 mutations and oestrogen receptor-negative cancer or PTEN mutation (treated with oral capivasertib 480 mg). Each cohort had a primary endpoint of confirmed objective response rate. For cohort A, 13 or more responses among 78 evaluable patients were required to infer activity and three or more among 16 were required for cohorts B, C, and D. Recruitment to all cohorts is complete and long-term follow-up is ongoing. This trial is registered with ClinicalTrials.gov, NCT03182634; the European Clinical Trials database, EudraCT2015-003735-36; and the ISRCTN registry, ISRCTN16945804.

FINDINGS

Between Dec 21, 2016, and April 26, 2019, 1051 patients registered for the study, with ctDNA results available for 1034 patients. Agreement between ctDNA digital PCR and targeted sequencing was 96-99% (n=800, kappa 0·89-0·93). Sensitivity of digital PCR ctDNA testing for mutations identified in tissue sequencing was 93% (95% CI 83-98) overall and 98% (87-100) with contemporaneous biopsies. In all cohorts, combined median follow-up was 14·4 months (IQR 7·0-23·7). Cohorts B and C met or exceeded the target number of responses, with five (25% [95% CI 9-49]) of 20 patients in cohort B and four (22% [6-48]) of 18 patients in cohort C having a response. Cohorts A and D did not reach the target number of responses, with six (8% [95% CI 3-17]) of 74 in cohort A and two (11% [1-33]) of 19 patients in cohort D having a response. The most common grade 3-4 adverse events were raised gamma-glutamyltransferase (13 [16%] of 80 patients; cohort A); diarrhoea (four [25%] of 20; cohort B); fatigue (four [22%] of 18; cohort C); and rash (five [26%] of 19; cohort D). 17 serious adverse reactions occurred in 11 patients, and there was one treatment-related death caused by grade 4 dyspnoea (in cohort C).

INTERPRETATION

ctDNA testing offers accurate, rapid genotyping that enables the selection of mutation-directed therapies for patients with breast cancer, with sufficient clinical validity for adoption into routine clinical practice. Our results demonstrate clinically relevant activity of targeted therapies against rare HER2 and AKT1 mutations, confirming these mutations could be targetable for breast cancer treatment.

FUNDING

Cancer Research UK, AstraZeneca, and Puma Biotechnology.

High Sensitivity of Circulating Tumor Cells Derived from a Colorectal Cancer Patient for Dual Inhibition with AKT and mTOR Inhibitors

Circulating tumor cells (CTCs) are cells shed from the primary tumor into the bloodstream. While many studies on solid tumor cells exist, data on CTCs are scarce. The mortality of cancer is mostly associated with metastasis and recent research identified CTCs as initiators of metastasis. The PI3K/AKT/mTOR signaling pathway is an intracellular pathway that regulates essential functions including protein biosynthesis, cell growth, cell cycle control, survival and migration. Importantly, activating oncogenic mutations and amplifications in this pathway are frequently observed in a wide variety of cancer entities, underlining the significance of this signaling pathway. In this study, we analyzed the functional role of the PI3K/AKT/mTOR signaling pathway in the CTC-MCC-41 line, derived from a patient with metastatic colorectal cancer. One striking finding in our study was the strong sensitivity of this CTC line against AKT inhibition using MK2206 and mTOR inhibition using RAD001 within the nanomolar range. This suggests that therapies targeting AKT and mTOR could have been beneficial for the patient from which the CTC line was isolated. Additionally, a dual targeting approach of AKT/mTOR inside the PI3K/AKT/mTOR signaling pathway in the colorectal CTCs showed synergistic effects in vitro. Depending on the phenotypical behavior of CTC-MCC-41 in cell culture (adherent vs. suspension), we identified altered phosphorylation levels inside the PI3K/AKT/mTOR pathway. We observed a downregulation of the PI3K/AKT/mTOR signaling pathway, but not of the RAS/RAF/MAPK pathway, in CTCs growing in suspension in comparison to adherent CTCs. Our results highlight distinct functions of AKT isoforms in CTC-MCC-41 cells with respect to cell proliferation. Knockdown of AKT1 and AKT2 leads to significantly impaired proliferation of CTC-MCC-41 cells in vitro. Therefore, our data demonstrate that the PI3K/AKT/mTOR signaling pathway plays a key role in the proliferation of CTC-MCC-41.

Probing the Highly Disparate Dual Inhibitory Mechanisms of Novel Quinazoline Derivatives against Mycobacterium tuberculosis Protein Kinases A and B

Mycobacterium tuberculosis (Mtb) serine/threonine (Ser/Thr) Protein kinases A (PknA) and B (PknB) have been identified as highly attractive targets for overcoming drug resistant tuberculosis. A recent lead series optimization study yielded compound 33 which exhibited potencies ~1000 times higher than compound 57. This huge discrepancy left us curious to investigate the mechanistic 'dual' (in)activities of the compound using computational methods, as carried out in this study. Findings revealed that 33 stabilized the PknA and B conformations and reduced their structural activities relative to 57. Optimal stability of 33 in the hydrophobic pockets further induced systemic alterations at the P-loops, catalytic loops, helix Cs and DFG motifs of PknA and B. Comparatively, 57 was more surface-bound with highly unstable motions. Furthermore, 33 demonstrated similar binding patterns in PknA and B, involving conserved residues of their binding pockets. Both π and hydrogen interactions played crucial roles in the binding of 33, which altogether culminated in high ΔGs for both proteins. On the contrary, the binding of 57 was characterized by unfavorable interactions with possible repulsive effects on its optimal dual binding to both proteins, as evidenced by the relatively lowered ΔGs. These findings would significantly contribute to the rational structure-based design of novel and highly selective dual inhibitors of Mtb PknA and B.

First-in-Human Study of AT13148, a Dual ROCK-AKT Inhibitor in Patients with Solid Tumors

PURPOSE

AT13148 is an oral AGC kinase inhibitor, which potently inhibits ROCK and AKT kinases. In preclinical models, AT13148 has been shown to have antimetastatic and antiproliferative activity.

PATIENTS AND METHODS

The trial followed a rolling six design during dose escalation. An intrapatient dose escalation arm to evaluate tolerability and a biopsy cohort to study pharmacodynamic effects were later added. AT13148 was administered orally three days a week (Mon-Wed-Fri) in 28-day cycles. Pharmacokinetic profiles were assessed using mass spectrometry and pharmacodynamic studies included quantifying p-GSK3β levels in platelet-rich plasma (PRP) and p-cofilin and p-MLC2 levels in tumor biopsies.

RESULTS

Fifty-one patients were treated on study. The safety of 5-300 mg of AT13148 was studied. Further, the doses of 120-180-240 mg were studied in an intrapatient dose escalation cohort. The dose-limiting toxicities included hypotension (300 mg), pneumonitis, and elevated liver enzymes (240 mg), and skin rash (180 mg). The most common side effects were fatigue, nausea, headaches, and hypotension. On the basis of tolerability, 180 mg was considered the maximally tolerated dose. At 180 mg, mean C max and AUC were 400 nmol/L and 13,000 nmol/L/hour, respectively. At 180 mg, ≥50% reduction of p-cofilin was observed in 3 of 8 posttreatment biopsies.

CONCLUSIONS

AT13148 was the first dual potent ROCK-AKT inhibitor to be investigated for the treatment of solid tumors. The narrow therapeutic index and the pharmacokinetic profile led to recommend not developing this compound further. There are significant lessons learned in designing and testing agents that simultaneously inhibit multiple kinases including AGC kinases in cancer.

Fetuin B overexpression suppresses proliferation, migration, and invasion in prostate cancer by inhibiting the PI3K/AKT signaling pathway

Fetuin B (FETUB) is a glycoprotein that is a member of the cysteine protease inhibitor family, and it is associated with cancer. However, the role of FETUB in prostate carcinogenesis is unknown. In this study, we overexpressed FETUB in prostate cancer cells by using lentivirus and then studied the impacts on cell apoptosis, migration and invasion. We found that apoptosis was increased and the migration and invasion of prostate cancer cells were significantly inhibited after overexpression. Then, we performed experiments in vivo and found that there were fewer tumors in the overexpression groups than in the control groups. In addition, we demonstrated that overexpression of FETUB inactivates the PI3K/AKT signaling pathway. Rescue assays revealed that intervention of 740Y-P reversed the anti-tumor effect of FETUB on prostate cancer cells. Taken together, our results revealed that FETUB may act as a novel regulator to promote apoptosis and inhibit the migration and invasion of prostate cancer cells and that FETUB is related to the inactivation of the PI3K/AKT signaling pathway.