Akt inhibitors: mechanism of action and implications for anticancer therapeutics

Treatment-related adverse events in patients with advanced breast cancer receiving adjuvant AKT inhibitors: a meta-analysis of randomized controlled trials

INTRODUCTION

Incorporation of AKT inhibitors into adjuvant therapy for advanced or metastatic breast cancer has improved clinical outcomes. However, the safety of AKT inhibitors should be better evaluated, given the possibility of prolonging survival and impacting patient quality of life. Our aim was to assess how the addition of AKT inhibitors to adjuvant therapy affects treatment-related adverse events.

METHODS

We evaluated binary outcomes with risk ratios (RRs), with 95% confidence intervals (CIs). We used DerSimonian and Laird random-effect models for all endpoints. Heterogeneity was assessed using I2 statistics. R, version 4.2.3, was used for statistical analyses.

RESULTS

A total of seven RCTs comprising 1619 patients with BC. The adverse effects that show significance statistical favoring the occurrence of adverse effects in AKT inhibitor were diarrhea (RR 3.05; 95% CI 2.48-3.75; p < 0.00001; I2 = 49%), hyperglycemia (RR 3.4; 95% CI 1.69-6.83; p = 0.00058; I2 = 75%), nausea (RR 1.69; 95% CI 1.34-2.13; p = 0.000008; I2 = 42%), rash (RR 2.79; 95% CI 1.49-5.23; p = 0.0013; I2 = 82%), stomatitis (RR 2.24; 95% CI 1.69-2.97; p < 0.00001; I2 = 16%) and vomiting (RR 2.99; 95% CI 1.85-4.86; p = 0.00009; I2 = 42%). There was no significant difference between the groups for alopecia (p = 0.80), fatigue (p = 0.087), and neuropathy (p = 0.363380).

CONCLUSION

The addition of AKT inhibitors to adjuvant therapy was associated with an increase in treatment-related adverse events. These results provide safety information for further clinical trials evaluating AKT inhibitor therapy for patients with metastatic BC. Clinicians should closely monitor patients for treatment-related adverse events to avoid discontinuation of therapy and morbidity caused by these early-stage therapies.

Targeting autophagy drug discovery: Targets, indications and development trends

Autophagy plays a vital role in sustaining cellular homeostasis and its alterations have been implicated in the etiology of many diseases. Drugs development targeting autophagy began decades ago and hundreds of agents were developed, some of which are licensed for the clinical usage. However, no existing intervention specifically aimed at modulating autophagy is available. The obstacles that prevent drug developments come from the complexity of the actual impact of autophagy regulators in disease scenarios. With the development and application of new technologies, several promising categories of compounds for autophagy-based therapy have emerged in recent years. In this paper, the autophagy-targeted drugs based on their targets at various hierarchical sites of the autophagic signaling network, e.g., the upstream and downstream of the autophagosome and the autophagic components with enzyme activities are reviewed and analyzed respectively, with special attention paid to those at preclinical or clinical trials. The drugs tailored to specific autophagy alone and combination with drugs/adjuvant therapies widely used in clinical for various diseases treatments are also emphasized. The emerging drug design and development targeting selective autophagy receptors (SARs) and their related proteins, which would be expected to arrest or reverse the progression of disease in various cancers, inflammation, neurodegeneration, and metabolic disorders, are critically reviewed. And the challenges and perspective in clinically developing autophagy-targeted drugs and possible combinations with other medicine are considered in the review.

Molecular insights into the behavior of the allosteric and ATP-competitive inhibitors in interaction with AKT1 protein: A molecular dynamics study

AKT1 is a family of serine/threonine kinases that play a key role in regulating cell growth, proliferation, metabolism, and survival. Two significant classes of AKT1 inhibitors (allosteric and ATP-competitive) are used in clinical development, and both of them could be effective in specific conditions. In this study, we investigated the effect of several different inhibitors on two conformations of the AKT1 by computational approach. We studied the effects of four inhibitors, including MK-2206, Miransertib, Herbacetin, and Shogaol, on the inactive conformation of AKT1 protein and the effects of four inhibitors, Capivasertib, AT7867, Quercetin, and Oridonin molecules on the active conformation of AKT1 protein. The results of simulations showed that each inhibitor creates a stable complex with AKT1 protein, although AKT1/Shogaol and AKT1/AT7867 complexes showed less stability than other complexes. Based on RMSF calculations, the fluctuation of residues in the mentioned complexes is higher than in other complexes. As compared to other complexes in either of its two conformations, MK-2206 has a stronger binding free energy affinity in the inactive conformation, -203.446 kJ/mol. MM-PBSA calculations showed that the van der Waals interactions contribute more than the electrostatic interactions to the binding energy of inhibitors to AKT1 protein.

Mechano-cytoskeleton remodeling mechanism and molecular docking studies on nanosurface technology: Titania nanotube arrays

In biomedical implant technology, nanosurface such as titania nanotube arrays (TNA) could provide better cellular adaptation, especially for long-term tissue acceptance response. Mechanotransduction activities of TNA nanosurface could involve the cytoskeleton remodeling mechanism. However, there is no clear insight into TNA mechano-cytoskeleton remodeling activities, especially computational approaches. Epithelial cells have played critical interface between biomedical implant surface and tissue acceptance, particularly for long-term interaction. Therefore, this study investigates genomic responses that are responsible for cell-TNA mechano-stimulus using epithelial cells model. Findings suggested that cell-TNA interaction may improve structural and extracellular matrix (ECM) support on the cells as an adaptive response toward the nanosurface topography. More specifically, the surface topography of the TNA might improve the cell polarity and adhesion properties via the interaction of the plasma membrane and intracellular matrix responses. TNA nanosurface might engross the cytoskeleton remodeling activities for multidirectional cell movement and cellular protrusions on TNA nanosurface. These observations are supported by the molecular docking profiles that determine proteins' in silico binding mechanism on TNA. This active cell-surface revamping would allow cells to adapt to develop a protective barrier toward TNA nanosurface, thus enhancing biocompatibility properties distinctly for long-term interaction. The findings from this study will be beneficial toward nano-molecular knowledge of designing functional nanosurface technology for advanced medical implant applications.

Serum and glucocorticoid-regulated kinase 1: Structure, biological functions, and its inhibitors

Serum and glucocorticoid-regulated kinase 1 (SGK1) is a serine/threonine kinase belonging to the protein kinase A, G, and C (AGC) family. Upon initiation of the phosphoinositide 3-kinase (PI3K) signaling pathway, mammalian target of rapamycin complex 2 (mTORC2) and phosphoinositide-dependent protein kinase 1 (PDK1) phosphorylate the hydrophobic motif and kinase domain of SGK1, respectively, inducing SGK1 activation. SGK1 modulates essential cellular processes such as proliferation, survival, and apoptosis. Hence, dysregulated SGK1 expression can result in multiple diseases, including hypertension, cancer, autoimmunity, and neurodegenerative disorders. This review provides a current understanding of SGK1, particularly in sodium transport, cancer progression, and autoimmunity. In addition, we summarize the developmental status of SGK1 inhibitors, their structures, and respective potencies evaluated in pre-clinical experimental settings. Collectively, this review highlights the significance of SGK1 and proposes SGK1 inhibitors as potential drugs for treatment of clinically relevant diseases.

From Serendipity to Rational Identification of the 5,6,7,8-Tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one Core as a New Chemotype of AKT1 Inhibitors for Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous hematopoietic malignancy whose prognosis is globally poor. In more than 60% of AML patients, the PI3K/AKTs/mTOR signaling pathway is aberrantly activated because of oncogenic driver alterations and further enhanced by chemotherapy as a mechanism of drug resistance. Against this backdrop, very recently we have started a multidisciplinary research project focused on AKT1 as a pharmacological target to identify novel anti-AML agents. Indeed, the serendipitous finding of the in-house compound T187 as an AKT1 inhibitor has paved the way to the rational identification of new active small molecules, among which T126 has emerged as the most interesting compound with IC₅₀ = 1.99 ± 0.11 μM, ligand efficiency of 0.35, and a clear effect at low micromolar concentrations on growth inhibition and induction of apoptosis in AML cells. The collected results together with preliminary SAR data strongly indicate that the 5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one derivative T126 is worthy of future biological experiments and medicinal chemistry efforts aimed at developing a novel chemical class of AKT1 inhibitors as anti-AML agents.

Chitosan Oligosaccharide Prevents Afatinib-Induced Barrier Disruption and Chloride Secretion through Modulation of AMPK, PI3K/AKT, and ERK Signaling in T84 Cells

Diarrhea is an important adverse effect of epidermal growth factor receptor-tyrosine kinase inhibitors, especially afatinib. Novel antidiarrheal agents are needed to reduce epidermal growth factor receptor-tyrosine kinase inhibitor-associated diarrhea to improve the quality of life and treatment outcome in cancer patients. This study aimed to investigate the anti-diarrheal activity of chitosan oligosaccharide against afatinib-induced barrier disruption and chloride secretion in human intestinal epithelial cells (T84 cells). Chitosan oligosaccharide (100 μg/mL) prevented afatinib-induced barrier disruption determined by changes in transepithelial electrical resistance and FITC-dextran flux in the T84 cell monolayers. In addition, chitosan oligosaccharide prevented afatinib-induced potentiation of cAMP-induced chloride secretion measured by short-circuit current analyses in the T84 cell monolayers. Chitosan oligosaccharide induced the activation of AMPK, a positive regulator of epithelial tight junction and a negative regulator of cAMP-induced chloride secretion. Moreover, chitosan oligosaccharide partially reversed afatinib-induced AKT inhibition without affecting afatinib-induced ERK inhibition via AMPK-independent mechanisms. Collectively, this study reveals that chitosan oligosaccharide prevents the afatinib-induced diarrheal activities in T84 cells via both AMPK-dependent and AMPK-independent mechanisms. Chitosan oligosaccharide represents a promising natural polymer-derived compound for further development of treatment for afatinib-associated diarrheas.

Role of PI3K-AKT-mTOR Pathway as a Pro-Survival Signaling and Resistance-Mediating Mechanism to Therapy of Prostate Cancer

Androgen deprivation therapy (ADT) and androgen receptor (AR)-targeted therapy are the gold standard options for treating prostate cancer (PCa). These are initially effective, as localized and the early stage of metastatic disease are androgen- and castration-sensitive. The tumor strongly relies on systemic/circulating androgens for activating AR signaling to stimulate growth and progression. However, after a certain point, the tumor will eventually develop a resistant stage, where ADT and AR antagonists are no longer effective. Mechanistically, it seems that the tumor becomes more aggressive through adaptive responses, relies more on alternative activated pathways, and is less dependent on AR signaling. This includes hyperactivation of PI3K-AKT-mTOR pathway, which is a central signal that regulates cell pro-survival/anti-apoptotic pathways, thus, compensating the blockade of AR signaling. The PI3K-AKT-mTOR pathway is well-documented for its crosstalk between genomic and non-genomic AR signaling, as well as other signaling cascades. Such a reciprocal feedback loop makes it more complicated to target individual factor/signaling for treating PCa. Here, we highlight the role of PI3K-AKT-mTOR signaling as a resistance mechanism for PCa therapy and illustrate the transition of prostate tumor from AR signaling-dependent to PI3K-AKT-mTOR pathway-dependent. Moreover, therapeutic strategies with inhibitors targeting the PI3K-AKT-mTOR signal used in clinic and ongoing clinical trials are discussed.

Nobiletin-induced partial abrogation of deleterious effects of AKT inhibition on preimplantation bovine embryo development in vitro

During preimplantational embryo development, PI3K/AKT regulates cell proliferation and differentiation and nobiletin modulates this pathway to promote cell survival. Therefore, we aimed to establish whether, when the AKT cascade is inhibited using inhibitors III and IV, nobiletin supplementation to in vitro culture media during the minor (2 to 8-cell stage, MNEGA) or major (8 to 16-cell stage, MJEGA) phases of EGA is able to modulate the development and quality of bovine embryos. In vitro zygotes were cultured during MNEGA or MJEGA phase in SOF + 5% FCS or supplemented with: 15 μM AKT-InhIII; 10 μM AKT-InhIV; 10 μM nobiletin; nobiletin+AKT-InhIII; nobiletin+AKT-InhIV; 0.03% DMSO. Embryo development was lower in treatments with AKT inhibitors, while combination of nobiletin with AKT inhibitors was able to recover their adverse developmental effect and also increase blastocyst cell number. The mRNA abundance of GPX1, NFE2L2, and POU5F1 was partially increased in 8- and 16-cell embryos from nobiletin with AKT inhibitors. Besides, nobiletin increased the p-rpS6 level whether or not AKT inhibitors were present. In conclusion, nobiletin promotes bovine embryo development and quality and partially recovers the adverse developmental effect of AKT inhibitors which infers that nobiletin probably uses another signalling cascade that PI3K/AKT during early embryo development in bovine.

Mitochondria: The metabolic switch of cellular oncogenic transformation

Mitochondria, well recognized as the "powerhouse" of cells, are maternally inherited organelles with bacterial ancestry that play essential roles in a myriad of cellular functions. It has become profoundly evident that mitochondria regulate a wide array of cellular and metabolic functions, including biosynthetic metabolism, cell signaling, redox homeostasis, and cell survival. Correspondingly, defects in normal mitochondrial functioning have been implicated in various human malignancies. Cancer development involves the activation of oncogenes, inactivation of tumor suppressor genes, and impairment of apoptotic programs in cells. Mitochondria have been recognized as the site of key metabolic switches for normal cells to acquire a malignant phenotype. This review outlines the role of mitochondria in human malignancies and highlights potential aspects of mitochondrial metabolism that could be targeted for therapeutic development.

Innovations in targeted therapies for triple negative breast cancer

PURPOSE OF REVIEW

Triple negative breast cancer (TNBC) is defined by a lack of targets, namely hormone receptor (HR) expression and human epidermal growth factor receptor 2 amplification. Cytotoxic chemotherapy remains the mainstay of treatment. Though TNBC constitutes approximately 10-15% of breast cancer, it is disproportionally lethal, but it is hoped that outcomes will improve as targetable oncogenic drivers are identified.

RECENT FINDINGS

Translational work in TNBC has focused on subsets defined by defects in homologous recombination repair, immune cell infiltration, or programmed death ligand receptor 1 expression, an over-active phosphoinositide-3 kinase pathway, or expression of androgen receptors. Though not specific to TNBC, the novel cell surface antigen trophoblast antigen 2 has also been identified and successfully targeted. This work has led to Food and Drug Administration approvals for small molecule poly-ADP-ribosyl polymerase inhibitors in patients with deleterious germline mutations in BRCA1 or BRCA2, the combination of nab-paclitaxel with immune checkpoint inhibitor antibodies in the first-line metastatic setting for programmed death ligand receptor 1+ TNBC, and use of the antibody-drug conjugate sacituzumab govitecan in the later-line metastatic setting.

SUMMARY

Identification of targetable oncogenic drivers in TNBC is an area of intense cancer biology research, hopefully translating to new therapies and improved outcomes.

Piperlongumine inhibits head and neck squamous cell carcinoma proliferation by docking to Akt

Piperlongumine (PL) is a biologically active alkaloid isolated from the long pepper roots and widely used as a traditional medicine in Ayurvedic medicine. However, the mechanism of PL's effect on head and neck squamous cell carcinoma (HNSCC) is not well understood. We performed cell experiments to confirm PL's inhibitory effect on HNSCC and employing cisplatin as positive control. Next, we conducted bioinformatics to predict PL's potential targets and verified by western blotting. Molecular docking, Biacore experiment and kinase activity assays were applied to elucidate the mechanism by which PL inhibited target activity. In vivo efficacy was verified by xenotransplantation and immunohistochemistry. PL inhibited proliferation, promoted late apoptosis, arrested cell cycle and inhibited DNA replication of the HEp-2 and FaDu cell lines. Employing bioinformatics, we found that PL's target was Akt and PL attenuated Akt phosphorylation. We found from molecular docking, Biacore experiment and kinase activity assay that PL inhibited Akt activation by docking to Akt to restrain its activity. In addition, PL significantly inhibited the growth of xenograft tumors by down regulating the expression of p-Akt in vivo. This study provides new insights into the molecular functions of PL and indicate its potential as a therapeutic agent for HNSCC.

Personalized Treatment of H3K27M-Mutant Pediatric Diffuse Gliomas Provides Improved Therapeutic Opportunities

Diffuse gliomas with K27M histone mutations (H3K27M glioma) are generally characterized by a fatal prognosis, particularly affecting the pediatric population. Based on the molecular heterogeneity observed in this tumor type, personalized treatment is considered to substantially improve therapeutic options. Therefore, clinical evidence for therapy, guided by comprehensive molecular profiling, is urgently required. In this study, we analyzed feasibility and clinical outcomes in a cohort of 12 H3K27M glioma cases treated at two centers. Patients were subjected to personalized treatment either at primary diagnosis or disease progression and received backbone therapy including focal irradiation. Molecular analyses included whole-exome sequencing of tumor and germline DNA, RNA-sequencing, and transcriptomic profiling. Patients were monitored with regular clinical as well as radiological follow-up. In one case, liquid biopsy of cerebrospinal fluid (CSF) was used. Analyses could be completed in 83% (10/12) and subsequent personalized treatment for one or more additional pharmacological therapies could be recommended in 90% (9/10). Personalized treatment included inhibition of the PI3K/AKT/mTOR pathway (3/9), MAPK signaling (2/9), immunotherapy (2/9), receptor tyrosine kinase inhibition (2/9), and retinoic receptor agonist (1/9). The overall response rate within the cohort was 78% (7/9) including one complete remission, three partial responses, and three stable diseases. Sustained responses lasting for 28 to 150 weeks were observed for cases with PIK3CA mutations treated with either miltefosine or everolimus and additional treatment with trametinib/dabrafenib in a case with BRAFV600E mutation. Immune checkpoint inhibitor treatment of a case with increased tumor mutational burden (TMB) resulted in complete remission lasting 40 weeks. Median time to progression was 29 weeks. Median overall survival (OS) in the personalized treatment cohort was 16.5 months. Last, we compared OS to a control cohort (n = 9) showing a median OS of 17.5 months. No significant difference between the cohorts could be detected, but long-term survivors (>2 years) were only present in the personalized treatment cohort. Taken together, we present the first evidence of clinical efficacy and an improved patient outcome through a personalized approach at least in selected cases of H3K27M glioma.

Targeting AKT for cancer therapy

Introduction: Targeted therapies in cancer aim to inhibit specific molecular targets responsible for enhanced tumor growth. AKT/PKB (protein kinase B) is a serine threonine kinase involved in several critical cellular pathways, including survival, proliferation, invasion, apoptosis, and angiogenesis. Although phosphatidylinositol-3 kinase (PI3K) is the key regulator of AKT activation, numerous stimuli and kinases initiate pro-proliferative AKT signaling which results in the activation of AKT pathway to drive cellular growth and survival. Activating mutations and amplification of components of the AKT pathway are implicated in the pathogenesis of many cancers including breast and ovarian. Given its importance, AKT, it has been validated as a promising therapeutic target.Areas covered: This article summarizes AKT's biological function and different classes of AKT inhibitors as anticancer agents. We also explore the efficacy of AKT inhibitors as monotherapies and in combination with cytotoxic and other targeted therapies.Expert opinion: The complex mechanism following AKT inhibition requires the addition of other therapies to prevent resistance and improve clinical response. Further studies are necessary to determine additional rational combinations that can enhance efficacy of AKT inhibitors, potentially by targeting compensatory mechanisms, and/or enhancing apoptosis. The identification of biomarkers of response is essential for the development of successful therapeutics.

Induction of Apoptosis Scutellaria baicalensis Georgi Root Extract by Inactivation of the Phosphatidyl Inositol 3-kinase/Akt Signaling Pathway in Human Leukemia U937 Cells

Background

The roots of Scutellaria baicalensis Georgi (Labiatae) have been widely used in traditional medicine for treatment of various diseases. In this study, we investigated the effects of ethanol extracts of S. baicalensis roots (EESB) on the growth ofn human leukemia U937 cells.

Methods

The effect of EESB on cell viability was measured by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. Apoptosis was determined using 4,6-diamidino-2-phenyllindile staining and flow cytometry. The effects of EESB on the expression of regulatory proteins of apoptosis and phosphatidyl inositol 3-kinase (PI3K)/Akt signaling were determined by Western blotting. Caspase activity and mitochondrial membrane potential (MMP) were measured using flow cytometric analysis.

Results

EESB significantly inhibited the growth of U937 cells and induced apoptosis, which was associated with down-regulation of anti-apoptotic Bcl-2, up-regulation of pro-apoptotic Bax, the loss of MMP and activation of caspase-9 and -3. We also found that EESB enhanced the expression of death receptors (DRs) and their associated ligands and induced the activation of caspase-8 and truncation of Bid. In addition, EESB suppressed PI3K/Akt signaling and EESB-induced apoptosis and growth inhibition were further increased by inhibition of PI3K activity.

Conclusions

Our results indicated that the pro-apoptotic effect of EESB was mediated through the activation of DR-mediated intrinsic and mitochondria-mediated extrinsic apoptosis pathways and inhibition of the PI3K/Akt signaling in U937 cells.

Ligand-based modeling of Akt3 lead to potent dual Akt1/Akt3 inhibitor

Akt1 and Akt3 are important serine/threonine-specific protein kinases involved in G2 phase required by cancer cells to maintain cell cycle and to prevent cell death. Accordingly, inhibitors of these kinases should have potent anti-cancer properties. This prompted us to use pharmacophore/QSAR modeling to identify optimal binding models and physicochemical descriptors that explain bioactivity variation within a set of 74 diverse Akt3 inhibitors. Two successful orthogonal pharmacophores were identified and further validated using receiver operating characteristic (ROC) curve analyses. The pharmacophoric models and associated QSAR equation were applied to screen the national cancer institute (NCI) list of compounds for new Akt3 inhibitors. Six hits showed significant experimental anti-Akt3 IC₅₀ values, out of which one compound exhibited dual low micromolar anti-Akt1 and anti-Akt3 inhibitory profiles.

Functional role of AKT signaling in bovine early embryonic development: potential link to embryotrophic actions of follistatin

BACKGROUND

TGF-β signaling pathways regulate several crucial processes in female reproduction. AKT is a non-SMAD signaling pathway regulated by TGF-β ligands essential for oocyte maturation and early embryonic development in the mouse, but its regulatory role in bovine early embryonic development is not well established. Previously, we demonstrated a stimulatory role for follistatin (a binding protein for specific members of TGF-β superfamily) in early bovine embryonic development. The objectives of the present studies were to determine the functional role of AKT signaling in bovine early embryonic development and embryotrophic actions of follistatin.

METHODS

We used AKT inhibitors III and IV as pharmacological inhibitors of AKT signaling pathway during the first 72 h of in vitro embryo culture. Effects of AKT inhibition on early embryonic development and AKT phosphorylation were investigated in the presence or absence of exogenous follistatin.

RESULTS

Pharmacological inhibition of AKT signaling resulted in a significant reduction in early embryo cleavage, and development to the 8- to 16-cell and blastocyst stages (d7). Treatment with exogenous follistatin increased AKT phosphorylation and rescued the inhibitory effect of AKT inhibitors III and IV on AKT phosphorylation and early embryonic development.

CONCLUSIONS

Collectively, results suggest a potential requirement of AKT for bovine early embryonic development, and suggest a potential role for follistatin in regulation of AKT signaling in early bovine embryos.

Network dynamics-based cancer panel stratification for systemic prediction of anticancer drug response

Cancer is a complex disease involving multiple genomic alterations that disrupt the dynamic response of signaling networks. The heterogeneous nature of cancer, which results in highly variable drug response, is a major obstacle to developing effective cancer therapy. Previous studies of cancer therapeutic response mostly focus on static analysis of genome-wide alterations, thus they are unable to unravel the dynamic, network-specific origin of variation. Here we present a network dynamics-based approach to integrate cancer genomics with dynamics of biological network for drug response prediction and design of drug combination. We select the p53 network as an example and analyze its cancer-specific state transition dynamics under distinct anticancer drug treatments by attractor landscape analysis. Our results not only enable stratification of cancer into distinct drug response groups, but also reveal network-specific drug targets that maximize p53 network-mediated cell death, providing a basis to design combinatorial therapeutic strategies for distinct cancer genomic subtypes.

Genomic alterations underlie the variability of drug responses between cancers, but our mechanistic understanding is limited. Here the authors use the p53 network to study how rewiring of signalling networks by genomic alterations impact their dynamic response to pharmacological perturbation.

Structural optimization elaborates novel potent Akt inhibitors with promising anticancer activity

Targeting of Akt has been validated as a well rationalized approach to cancer treatment, and represents a promising therapeutic strategy for aggressive hematologic malignancies. We describe herein an exploration of novel Akt inhibitors for cancer therapy through structural optimization of previously described 4-(piperazin-1-yl)-7H-pyrrolo[2,3-d]pyrimidine derivatives. Our studies yielded a novel series of pyrrolopyrimidine based phenylpiperidine carboxamides capable of potent inhibition of Akt1. Notably, 10h exhibited robust antiproliferative effects in both mantle cell lymphoma cell lines and primary patient tumor cells. Low micromolar doses of 10h induced cell apoptosis and cell cycle arrest in G₂/M phase, and significantly downregulated the phosphorylation of Akt downstream effectors GSK3β and S6 in Jeko-1 cells.

10-Gingerol as an inducer of apoptosis through HTR1A in cumulus cells: In-vitro and in-silico studies

Objectives

Cumulus cells play a crucial role as essential mediators in the maturation of ova. Ginger contains 10-gingerol, which induces apoptosis in colon cancer cells. Based on this hypothesis, this study aimed to determine whether 10-gingerol is able to induce apoptosis in normal cells, namely, cumulus cells.

Methods

This study used an in vitro analysis by culturing Cumulus cells in M199 containing 10-gingerol in various concentrations (12, 16, and 20 μM) and later detected early apoptotic activity using an Annexin V-FITC detection kit.

Result

The in vitro data revealed that the number of apoptosis cells increased along with the period of incubation as follows: 12 μM (63.71% ± 2.192%); 16 μM (74.51% ± 4.596%); and 20 μM (78.795% ± 1.435%). The substance 10-gingerol induces apoptosis in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT-1.

Conclusions

These findings indicate that further examination is warranted for 10-gingerol as a contraception agent.

NSCA-1-a novel N-substituted coumalamide derivative-increases Adriamycin sensitivity in HepG2/adriamycin cells through modulating Akt/GSK-3β signaling and p53-dependant apoptotic pathway

Coumalamide derivatives are one of 2-pyrones derivatives, exerting multifunctional bioactivity. An array of coumalamide derivatives have been developed and presented good antiproliferative properties on cancer cells. However, the synthesis of 5-substituted coumalamide derivatives has not yet been published. Resistance to chemotherapeutic drugs is a major obstacle in hepatocellular carcinoma therapy. Recent evidence suggests that overexpression of constitutively active Akt confers on cancer cells resistance to chemotherapy. In this study, we report the synthesis and biological evaluation of a novel N-substituted coumalamide derivative (NSCA-1). The results indicated that NSCA-1 exerts synergistic cytotoxicity with Adriamycin in HepG2/ADR (HepG2/adriamycin) cells. Furthermore, both of the Akt kinase activity and phosphorylated Akt (Ser473) were found to be inhibited by NSCA-1 and subsequently resulting in decreased phosphorylation of GSK-3β. The intracellular accumulation of Adriamycin was also boosted by NSCA-1 via reducing the expression of p-gp. In addition, we found that combined treatment with NSCA-1 enhance cell apoptosis induced by Adriamycin via p53-dependant apoptotic pathway.

Discovery of 3-(3-(4-(1-Aminocyclobutyl)phenyl)-5-phenyl-3H-imidazo[4,5-b]pyridin-2-yl)pyridin-2-amine (ARQ 092): An Orally Bioavailable, Selective, and Potent Allosteric AKT Inhibitor

The work in this paper describes the optimization of the 3-(3-phenyl-3H-imidazo[4,5-b]pyridin-2-yl)pyridin-2-amine chemical series as potent, selective allosteric inhibitors of AKT kinases, leading to the discovery of ARQ 092 (21a). The cocrystal structure of compound 21a bound to full-length AKT1 confirmed the allosteric mode of inhibition of this chemical class and the role of the cyclobutylamine moiety. Compound 21a demonstrated high enzymatic potency against AKT1, AKT2, and AKT3, as well as potent cellular inhibition of AKT activation and the phosphorylation of the downstream target PRAS40. Compound 21a also served as a potent inhibitor of the AKT1-E17K mutant protein and inhibited tumor growth in a human xenograft mouse model of endometrial adenocarcinoma.

Somatic copy number alterations detected by ultra-deep targeted sequencing predict prognosis in oral cavity squamous cell carcinoma

Background

Ultra-deep targeted sequencing (UDT-Seq) has advanced our knowledge on the incidence and functional significance of somatic mutations. However, the utility of UDT-Seq in detecting copy number alterations (CNAs) remains unclear. With the goal of improving molecular prognostication and identifying new therapeutic targets, we designed this study to assess whether UDT-Seq may be useful for detecting CNA in oral cavity squamous cell carcinoma (OSCC).

Methods

We sequenced a panel of clinically actionable cancer mutations in 310 formalin-fixed paraffin-embedded OSCC specimens. A linear model was developed to overcome uneven coverage across target regions and multiple samples. The 5-year rates of secondary primary tumors, local recurrence, neck recurrence, distant metastases, and survival served as the outcome measures. We confirmed the prognostic significance of the CNA signatures in an independent sample of 105 primary OSCC specimens.

Results

The CNA burden across 10 targeted genes was found to predict prognosis in two independent cohorts. FGFR1 and PIK3CAamplifications were associated with prognosis independent of clinical risk factors. Genes exhibiting CNA were clustered in the proteoglycan metabolism, the FOXO signaling, and the PI3K-AKT signaling pathways, for which targeted drugs are already available or currently under development.

Conclusions

UDT-Seq is clinically useful to identify CNA, which significantly improve the prognostic information provided by traditional clinicopathological risk factors in OSCC patients.

Akt2/ZEB2 may be a biomarker for exfoliant cells in ascitic fluid in advanced grades of serous ovarian carcinoma

Ovarian cancers present a mild clinical course when diagnosed early but an aggressive pathway when diagnosed in the peri- and postmenopausal periods. However, the predictability of tumor progression is stochastic and is difficult to predict. In the present study, we hypothesized to examine the key pathways that are dysregulated to promote epithelial-mesenchymal transition in serous ovarian carcinoma. Examination of these steps would help to identify ascitic fluid with cells poised for metastasis or otherwise. We focused on examining the Akt2 expression, mainly because of its report as being overamplified in the aggressive variants of ovarian cancer, as well as TGFbeta-sensitivity of Akt2 that forms the key basis for metastasis initiation of most kinds of carcinoma. We obtained primary ovarian carcinoma samples as well as ascitic fluid and distantly metastatic ovarian carcinoma to examine the expression of Akt2. The results of the study demonstrated that in malignant exfoliated ovarian cancer cells, Smad4 expression was tremendously increased in the nuclei, suggesting nuclear translocation of Smad, which thereafter may have activated ZEB2, and thereafter genomically affected the expression of E-cadherin, myosin II, and vimentin, key components for initiating and sustaining metastasis. All of these may have been stimulated by increased cellular expression of Akt2 in metastatic variants of the serous ovarian carcinoma. The reliance on Akt2 and TGF beta signaling may also potentiate the case for Akt inhibitors or small molecule inhibitors of TGFbeta signaling like doxycycline as adjunct chemotherapy in serous ovarian carcinoma, especially the metastatic variants.

Cross-laboratory validation of the OncoScan® FFPE Assay, a multiplex tool for whole genome tumour profiling

Background

Adoption of new technology in both basic research and clinical settings requires rigorous validation of analytical performance. The OncoScan® FFPE Assay is a multiplexing tool that offers genome-wide copy number and loss of heterozygosity detection, as well as identification of frequently tested somatic mutations.

Methods

In this study, 162 formalin fixed paraffin embedded samples, representing six different tumour types, were profiled in triplicate across three independent laboratories. OncoScan® formalin fixed paraffin embedded assay data was then analysed for reproducibility of genome-wide copy number, loss of heterozygosity and somatic mutations. Where available, somatic mutation data was compared to data from orthogonal technologies (pyro/sanger sequencing).

Results

Cross site comparisons of genome-wide copy number and loss of heterozygosity profiles showed greater than 95% average agreement between sites. Somatic mutations pre-validated by orthogonal technologies showed greater than 90% agreement with OncoScan® somatic mutation calls and somatic mutation concordance between sites averaged 97%.

Conclusions

Reproducibility of whole-genome copy number, loss of heterozygosity and somatic mutation data using the OncoScan® assay has been demonstrated with comparatively low DNA inputs from a range of highly degraded formalin fixed paraffin embedded samples. In addition, our data shows examples of clinically-relevant aberrations that demonstrate the potential utility of the OncoScan® assay as a robust clinical tool for guiding tumour therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-015-0079-z) contains supplementary material, which is available to authorized users.

Effects of platycodin D on proliferation, apoptosis and PI3K/Akt signal pathway of human glioma U251 cells

Effects of platycodin D (PD) on the proliferation, apoptosis and PI3K/Akt signaling pathway of human glioma U251 cells were investigated. Glioma U251 cells were treated with PD at final concentrations of 0, 16.3, 40.8, 81.6, 163.2 μM, and inhibition rate, early and late apoptotic rate, apoptotic index, expression of apoptosis-related proteins and phosphorylation of the PI3K/Akt signaling pathway were evaluated. The results showed that compared with the control group, PD could increase the proliferation inhibition rate of U251 cells in a dose- and time -dependent manner; PD could also elevate the early and late apoptotic rate, apoptotic index and the level of pro-apoptotic proteins of glioma U251 cells, such as Bax and cleaved caspase-3, but lower the level of apoptosis inhibitory protein, such as Bcl-2; PD could increase the ratio of G₀/G₁ phase U251 cells, and lower the proportion of Sphase U251 cells and the ratio of G₂/M phase U251 cells; PD could reduce the ratio of p-Akt/Akt. The results indicate that PD can inhibit the proliferation, induce the apoptosis and cause the cell cycle arrest in human glioma U251 cells, which may be related to the inhibition of PD on the activation of PI3K/Akt signaling pathway.

Clinical value of isoform-specific detection and targeting of AKT1, AKT2 and AKT3 in breast cancer

SUMMARY 

Overactivation of the PI3K/AKT signaling pathway is frequently reported in breast cancer, consequently inhibitors targeting this pathway are clinically useful. AKT constitutes a hub in the regulation of several cancer hallmarks, such as proliferation, survival and migration. Three AKT isoforms, named AKT1, AKT2 and AKT3, are identified in humans. AKT alterations, mainly upregulation of phosphorylated AKT in tumors may have prognostic and predictive value. Moreover, the AKT isoforms may possess partly divergent cellular functions and be upregulated in certain breast cancer subtypes, suggesting the importance of isoform-specific analyses. In conclusion, AKT isoform-specific detection and targeting in different tumor subtypes will hopefully result into a further developed personalized medicine.

Submicroscopic genomic rearrangements change gene expression in T-cell large granular lymphocyte leukemia

OBJECTIVES

To better understand the molecular pathogenesis of T-cell large granular lymphocyte leukemia (T-LGL), we decided to search for those genetic alterations in T-LGL patients and MOTN-1 cell line (established from T-LGL patient) that have an impact on gene expression and as a result can influence cell biology.

METHODS

Multicolor fluorescence in situ hybridization (mFISH) analysis of the MOTN-1 cell line was performed as well as paired-end next-generation sequencing (NGS; Illumina HiSeq2000) of this cell line and one T-LGL patient. In addition, chosen 6q region was characterized in three T-LGL patients using high-resolution comparative genomic hybridization (FT-CGH) and LM-PCR. Gene expression was studied by RNA sequencing (RNAseq; SOLID5500).

RESULTS

Rearrangements were detected within 1p and 2q in MOTN-1 affecting expression of FGR, ZEB2, and CASP8, and within 6q in MOTN-1 and one T-LGL patient affecting MAP3K5 and IFNGR1. Nineteen genes, among them FOXN3, RIN3, AKT1, PPP2R5C, were overexpressed as a result of an amplification in 14q in one T-LGL patient. Two novel fusion transcripts were identified: CASP8-ERBB4 in MOTN-1 and SBF1-PKHD1L1 in T-LGL patient.

CONCLUSIONS

This study showed that submicroscopic genomic rearrangements change gene expression in T-LGL. Several genes involved in rearrangements were previously linked to cancer and survival pattern that characterizes T-LGL cells.

Inhibition of ovarian cancer cell proliferation by Pien Tze Huang via the AKT-mTOR pathway

Pien Tze Huang (PZH) is a well-known Chinese medicine that has been used as a therapeutic drug in the treatment of a number of diseases, such as hepatocellular carcinoma and colon cancer. However, few studies have analyzed the effects of PZH on ovarian cancer cell proliferation. In the present study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell assays, cell cycle and apoptosis rate analyses and western blotting were conducted to investigate the effects of PZH on the proliferation rate of ovarian cancer cells and its potential molecular pathway. The results showed that PZH inhibits the proliferation of the human ovarian cancer OVCAR-3 cell line by blocking the progression of the cell cycle from the G₁ to S phase, however, PZH did not induce OVCAR-3 cell apoptosis. Increased PZH concentration may downregulate the expression of AKT, phosphorylated (p)-AKT, mammalian target of rapamycin (mTOR) and p-mTOR proteins in the OVCAR-3 cell line. In addition, it was observed that PZH may suppress the protein expression of cyclin-dependent kinase (CDK)4 and CDK6. Overall, the results of the present study indicated that PZH may inhibit ovarian cancer cell proliferation by modulating the activity of the AKT-mTOR pathway.