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Antimicrobial Agents and Chemotherapy Apr 2017Here the mechanism by which perifosine induced cell death in and is described. The drug reduced mitochondrial membrane potential and decreased cellular ATP levels...
Here the mechanism by which perifosine induced cell death in and is described. The drug reduced mitochondrial membrane potential and decreased cellular ATP levels while increasing phosphatidylserine externalization. Perifosine did not increase membrane permeabilization. We also found that the drug inhibited the phosphorylation of Akt in the parasites. These results highlight the potential use of perifosine as an alternative to miltefosine against .
Topics: Adenosine Triphosphate; Antiprotozoal Agents; Apoptosis; Gene Expression; Inhibitory Concentration 50; Leishmania donovani; Leishmania mexicana; Membrane Potential, Mitochondrial; Mitochondria; Phosphatidylserines; Phosphorylation; Phosphorylcholine; Proto-Oncogene Proteins c-akt; Protozoan Proteins
PubMed: 28096161
DOI: 10.1128/AAC.02127-16 -
Cell Death & Disease Jan 2017Human immunodeficiency virus-associated neurological disorders (HANDs) affect the majority of AIDS patients and are a significant problem among HIV-1-infected...
Human immunodeficiency virus-associated neurological disorders (HANDs) affect the majority of AIDS patients and are a significant problem among HIV-1-infected individuals who live longer because of combined anti-retroviral therapies. HIV-1 utilizes a number of viral proteins and subsequent cytokine inductions to unleash its toxicity on neurons. Among HIV-1 viral proteins, Nef is a small protein expressed abundantly in astrocytes of HIV-1-infected brains and has been suggested to have a role in the pathogenesis of HAND. In order to explore its effect in the central nervous system, HIV-1 Nef was expressed in primary human fetal astrocytes (PHFAs) using an adenovirus. Our results revealed that HIV-1 Nef is released in extracellular vesicles (EVs) derived from PHFA cells expressing the protein. Interestingly, HIV-1 Nef release in EVs was enriched significantly when the cells were treated with autophagy activators perifosine, tomaxifen, MG-132, and autophagy inhibitors LY294002 and wortmannin suggesting a novel role of autophagy signaling in HIV-1 Nef release from astrocytes. Next, Nef-carrying EVs were purified from astrocyte cultures and neurotoxic effects on neurons were analyzed. We observed that HIV-1 Nef-containing EVs were readily taken up by neurons as demonstrated by immunocytochemistry and immunoblotting. Furthermore, treatment of neurons with Nef-carrying EVs induced oxidative stress as evidenced by a decrease in glutathione levels. To further investigate its neurotoxic effects, we expressed HIV-1 Nef in primary neurons by adenoviral transduction. Intracellular expression of HIV-1 Nef caused axonal and neurite degeneration of neurons. Furthermore, expression of HIV-1 Nef decreased the levels of phospho-tau while enhancing total tau in primary neurons. In addition, treatment of primary neurons with Nef-carrying EVs suppressed functional neuronal action potential assessed by multielectrode array studies. Collectively, these data suggested that HIV-1 Nef can be a formidable contributor to neurotoxicity along with other factors, which leads to HAND in HIV-1-infected AIDS patients.
Topics: Astrocytes; Autophagy; Extracellular Vesicles; Fetus; HIV Infections; HIV-1; Humans; Neurons; Neurotoxicity Syndromes; Primary Cell Culture; nef Gene Products, Human Immunodeficiency Virus
PubMed: 28079886
DOI: 10.1038/cddis.2016.467 -
Oncotarget Jan 2017The potential effect of icariside II on dexamethasone-induced osteoblast cell damages was evaluated here. In MC3T3-E1 osteoblastic cells and the primary murine...
The potential effect of icariside II on dexamethasone-induced osteoblast cell damages was evaluated here. In MC3T3-E1 osteoblastic cells and the primary murine osteoblasts, co-treatment with icariside II dramatically attenuated dexamethasone- induced cell death and apoptosis. Icariside II activated Akt signaling, which is required for its actions in osteoblasts. Akt inhibitors (LY294002, perifosine and MK-2206) almost abolished icariside II-induced osteoblast cytoprotection against dexamethasone. Further studies showed that icariside II activated Nrf2 signaling, downstream of Akt, to inhibit dexamethasone-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary osteoblasts. On the other hand, Nrf2 shRNA knockdown inhibited icariside II-induced anti-dexamethasone cytoprotection in MC3T3-E1 cells. Finally, we showed that icariside II induced heparin-binding EGF (HB-EGF) production and EGFR trans-activation in MC3T3-E1 cells. EGFR inhibition, via anti-HB-EGF antibody, EGFR inhibitor AG1478 or EGFR shRNA knockdown, almost blocked icariside II-induced Akt-Nrf2 activation in MC3T3-E1 cells. Collectively, we conclude that icariside II activates EGFR-Akt-Nrf2 signaling and protects osteoblasts from dexamethasone. Icariside II might have translational value for the treatment of dexamethasone-associated osteoporosis/osteonecrosis.
Topics: Animals; Cell Line; Cell Proliferation; Cell Survival; Chromones; Dexamethasone; ErbB Receptors; Flavonoids; Heterocyclic Compounds, 3-Ring; Mice; Morpholines; NF-E2-Related Factor 2; Osteoblasts; Phosphorylcholine; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction
PubMed: 27911877
DOI: 10.18632/oncotarget.13732 -
Oncotarget Nov 2016The mechanisms leading to the development and progression of hepatocellular carcinoma (HCC) are complicated and regulated genetically and epigenetically. The recent...
Investigating the mechanism of hepatocellular carcinoma progression by constructing genetic and epigenetic networks using NGS data identification and big database mining method.
The mechanisms leading to the development and progression of hepatocellular carcinoma (HCC) are complicated and regulated genetically and epigenetically. The recent advancement in high-throughput sequencing has facilitated investigations into the role of genetic and epigenetic regulations in hepatocarcinogenesis. Therefore, we used systems biology and big database mining to construct genetic and epigenetic networks (GENs) using the information about mRNA, miRNA, and methylation profiles of HCC patients. Our approach involves analyzing gene regulatory networks (GRNs), protein-protein networks (PPINs), and epigenetic networks at different stages of hepatocarcinogenesis. The core GENs, influencing each stage of HCC, were extracted via principal network projection (PNP). The pathways during different stages of HCC were compared. We observed that extracellular signals were further transduced to transcription factors (TFs), resulting in the aberrant regulation of their target genes, in turn inducing mechanisms that are responsible for HCC progression, including cell proliferation, anti-apoptosis, aberrant cell cycle, cell survival, and metastasis. We also selected potential multiple drugs specific to prominent epigenetic network markers of each stage of HCC: lestaurtinib, dinaciclib, and perifosine against the NTRK2, MYC, and AKT1 markers influencing HCC progression from stage I to stage II; celecoxib, axitinib, and vinblastine against the DDIT3, PDGFB, and JUN markers influencing HCC progression from stage II to stage III; and atiprimod, celastrol, and bortezomib against STAT3, IL1B, and NFKB1 markers influencing HCC progression from stage III to stage IV.
Topics: Carcinoma, Hepatocellular; Computational Biology; DNA Methylation; Data Mining; Disease Progression; Epigenesis, Genetic; Gene Regulatory Networks; High-Throughput Nucleotide Sequencing; Humans; Liver Neoplasms; MicroRNAs; Neoplasm Staging; Sequence Analysis, DNA; Systems Biology
PubMed: 27821810
DOI: 10.18632/oncotarget.13100 -
World Journal of Clinical Oncology Oct 2016The Akt signal transduction pathway controls most hallmarks of cancer. Activation of the Akt cascade promotes a malignant phenotype and is also widely implicated in drug... (Review)
Review
The Akt signal transduction pathway controls most hallmarks of cancer. Activation of the Akt cascade promotes a malignant phenotype and is also widely implicated in drug resistance. Therefore, the modulation of Akt activity is regarded as an attractive strategy to enhance the efficacy of cancer therapy and irradiation. This pathway consists of phosphatidylinositol 3 kinase (PI3K), mammalian target of rapamycin, and the transforming serine-threonine kinase Akt protein isoforms, also known as protein kinase B. DNA-targeted agents, such as platinum agents, taxanes, and antimetabolites, as well as radiation have had a significant impact on cancer treatment by affecting DNA replication, which is aberrantly activated in malignancies. However, the caveat is that they may also trigger the activation of repairing mechanisms, such as upstream and downstream cascade of Akt survival pathway. Thus, each target can theoretically be inhibited in view of improving the potency of conventional treatment. Akt inhibitors, ., MK-2206 and perifosine, or PI3K modulators, ., LY294002 and Wortmannin, have shown some promising results in favor of sensitizing the cancer cells to the therapy and , which have provided the rationale for incorporation of these novel agents into multimodality treatment of different malignancies. Nevertheless, despite the acceptable safety profile of some of these agents in the clinical studies, with regard to the efficacy, the results are still too preliminary. Hence, we need to wait for the upcoming data from the ongoing trials before utilizing them into the standard care of cancer patients.
PubMed: 27777878
DOI: 10.5306/wjco.v7.i5.352 -
Tumour Biology : the Journal of the... Oct 2016Brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor TrkB have been reported to be associated with poor prognosis in neuroblastoma (NB) patients....
Brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor TrkB have been reported to be associated with poor prognosis in neuroblastoma (NB) patients. Our previous studies indicated that BDNF activation of TrkB induces chemo-resistance through activation of phosphoinositide-3-kinase (PI3K)/Akt pathway. In this study, we investigated the role of BDNF/TrkB on metastasis in NB. A tetracycline-regulated TrkB-expressing NB cell line (TB3) was used. Scratch wound healing assay, Boyden chamber migration, and invasion assays were performed to study the migration and invasion of TB3 cells. A tumor xenograft model using SCID-Beige mice was utilized to detect the metastasis of NB tumors in vivo. Inhibitors of PI3K, MAPK, Akt, and mTOR were used. Western blotting was performed to study the expressions of P-Akt, P-Erk, and P-mTOR. Our results showed that in TrkB-expressing NB cells, BDNF treatment significantly increased gap closing (P < 0.01) in scratch wound healing assay, also significantly enhanced the numbers of migrating cells (P < 0.01) and invading cells (P < 0.01) in the Boyden chamber migration and invasion assays. In vivo, NB distant metastases were significantly increased in mice with TrkB-expressing xenograft tumors compared to those with non-TrkB-expressing tumors (P < 0.05). Pre-treatment with any of the inhibitors for PI3K (LY294002), MAPK (PD98059), Akt (perifosine), or mTOR (rapamycin) blocked the BDNF/TrkB-induced increases of cell migration and invasion in TB3 cells, and also blocked the BDNF/TrkB-induced expressions of P-Akt, P-Erk, and P-mTOR. These data indicated that BDNF/TrkB increased metastasis in NB via PI3K/Akt/mTOR and MAPK pathways, and BDNF/TrkB and the downstream targets may be potential targets for the treatment of NB metastasis.
PubMed: 27752996
DOI: 10.1007/s13277-016-5433-z -
International Journal of Cancer Jan 2017AKT plays a pivotal role in driving the malignant phenotype of many cancers, including high-risk neuroblastoma (HR-NB). AKT signaling, however, is active in normal...
AKT plays a pivotal role in driving the malignant phenotype of many cancers, including high-risk neuroblastoma (HR-NB). AKT signaling, however, is active in normal tissues, raising concern about excessive toxicity from its suppression. The oral AKT inhibitor perifosine showed tolerable toxicity in adults and in our phase I trial in children with solid tumors (clinicaltrials.gov NCT00776867). We now report on the HR-NB experience. HR-NB patients received perifosine 50-75 mg m day after a loading dose of 100-200 mg m on day 1, and continued on study until progressive disease. The 27 HR-NB patients included three treated for primary refractory disease and 24 with disease resistant to salvage therapy after 1-5 (median 2) relapses; only one had MYCN-amplified HR-NB. Pharmacokinetic studies showed μM concentrations consistent with cytotoxic levels in preclinical models. Nine patients (all MYCN-non-amplified) remained progression-free through 43+ to 74+ (median 54+) months from study entry, including the sole patient to show a complete response and eight patients who had persistence of abnormal I-metaiodobenzylguanidine skeletal uptake but never developed progressive disease. Toxicity was negligible in all 27 patients, even with the prolonged treatment (11-62 months, median 38) in the nine long-term progression-free survivors. The clinical findings (i) confirm the safety of therapeutic serum levels of an AKT inhibitor in children; (ii) support perifosine for MYCN-non-amplified HR-NB as monotherapy after completion of standard treatment or combined with other agents (based on preclinical studies) to maximize antitumor effects; and (iii) highlight the welcome possibility that refractory or relapsed MYCN-non-amplified HR-NB is potentially curable.
Topics: Adolescent; Adult; Antineoplastic Agents; Child; Child, Preschool; Disease-Free Survival; Female; Humans; Male; Neoplasm Recurrence, Local; Neuroblastoma; Phosphatidylinositol 3-Kinases; Phosphorylcholine; Proto-Oncogene Proteins c-akt; Signal Transduction; Young Adult
PubMed: 27649927
DOI: 10.1002/ijc.30440 -
Biochimica Et Biophysica Acta Nov 2016Phosphatidylinositol analogs (PIAs) were originally designed to bind competitively to the Akt PH domain and prevent membrane translocation and activation....
d-3-Deoxy-dioctanoylphosphatidylinositol induces cytotoxicity in human MCF-7 breast cancer cells via a mechanism that involves downregulation of the D-type cyclin-retinoblastoma pathway.
Phosphatidylinositol analogs (PIAs) were originally designed to bind competitively to the Akt PH domain and prevent membrane translocation and activation. d-3-Deoxy-dioctanoylphosphatidylinositol (d-3-deoxy-diCPI), but not compounds with altered inositol stereochemistry (e.g., l-3-deoxy-diCPI and l-3,5-dideoxy-diCPI), is cytotoxic. However, high resolution NMR field cycling relaxometry shows that both cytotoxic and non-toxic PIAs bind to the Akt1 PH domain at the site occupied by the cytotoxic alkylphospholipid perifosine. This suggests that another mechanism for cytotoxicity must account for the difference in efficacy of the synthetic short-chain PIAs. In MCF-7 breast cancer cells, with little constitutively active Akt, d-3-deoxy-diCPI (but not l-compounds) decreases viability concomitant with increased cleavage of PARP and caspase 9, indicative of apoptosis. d-3-Deoxy-diCPI also induces a decrease in endogenous levels of cyclins D1 and D3 and blocks downstream retinoblastoma protein phosphorylation. siRNA-mediated depletion of cyclin D1, but not cyclin D3, reduces MCF-7 cell proliferation. Thus, growth arrest and cytotoxicity induced by the soluble d-3-deoxy-diCPI occur by a mechanism that involves downregulation of the D-type cyclin-pRb pathway independent of its interaction with Akt. This ability to downregulate D-type cyclins contributes, at least in part, to the anti-proliferative activity of d-3-deoxy-diCPI and may be a common feature of other cytotoxic phospholipids.
Topics: Breast Neoplasms; Cell Death; Cyclin D1; Down-Regulation; Female; Humans; MCF-7 Cells; Magnetic Resonance Spectroscopy; Phosphatidic Acids; Phosphatidylinositols; Phosphorylation; Pleckstrin Homology Domains; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Retinoblastoma Protein; Signal Transduction; p38 Mitogen-Activated Protein Kinases
PubMed: 27600289
DOI: 10.1016/j.bbalip.2016.09.001 -
Cancer Prevention Research... Oct 2016Patients with basal cell nevus syndrome (BCNS), also known as Gorlin syndrome, develop numerous basal cell carcinomas (BCC) due to germline mutations in the tumor...
Patients with basal cell nevus syndrome (BCNS), also known as Gorlin syndrome, develop numerous basal cell carcinomas (BCC) due to germline mutations in the tumor suppressor PTCH1 and aberrant activation of Hedgehog (Hh) signaling. Therapies targeted at components of the Hh pathway, including the smoothened (SMO) inhibitor vismodegib, can ablate these tumors clinically, but tumors recur upon drug discontinuation. Using SKH1-Ptch1 as a model that closely mimics the spontaneous and accelerated growth pattern of BCCs in patients with BCNS, we show that AKT1, a serine/threonine protein kinase, is intrinsically activated in keratinocytes derived from the skin of newborn Ptch1 mice in the absence of carcinogenic stimuli. Introducing Akt1 haplodeficiency in Ptch1 mice (Akt1 Ptch1) significantly abrogated BCC growth. Similarly, pharmacological inhibition of AKT with perifosine, an alkyl phospholipid AKT inhibitor, diminished the growth of spontaneous and UV-induced BCCs. Our data demonstrate an obligatory role for AKT1 in BCC growth, and targeting AKT may help reduce BCC tumor burden in BCNS patients. Cancer Prev Res; 9(10); 794-802. ©2016 AACR.
Topics: Animals; Basal Cell Nevus Syndrome; Carcinoma, Basal Cell; Cell Line; Disease Models, Animal; Humans; Keratinocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Proto-Oncogene Proteins c-akt; Skin Neoplasms
PubMed: 27388747
DOI: 10.1158/1940-6207.CAPR-16-0066 -
Journal of Translational Medicine May 2016Immune regulation is crucial for the pathogenesis of B-cell acute lymphoblastic leukemia (B-ALL). It has been reported that Th17 cells as a newly identified subset of...
Increased Th17 cells and IL-17A exist in patients with B cell acute lymphoblastic leukemia and promote proliferation and resistance to daunorubicin through activation of Akt signaling.
BACKGROUND
Immune regulation is crucial for the pathogenesis of B-cell acute lymphoblastic leukemia (B-ALL). It has been reported that Th17 cells as a newly identified subset of CD4(+) T cells are involved in the pathogenesis of several hematological disorders. However, the role of Th17 cells in the pathophysiology of B-ALL is still unclear.
METHODS
The frequencies of T cells were determined by flow cytometry in the peripheral blood and bone marrow of 44 newly diagnosed B-ALL patients and 25 age-matched healthy donors. The cell viability and apoptosis were determined by CCK-8 assay and Annexin V staining, respectively. Western blot was applied to identify the level of Akt and Stat3 phosphorylation.
RESULTS
We assessed and observed a significantly increased frequency of Th17 cells and a drastically decreased frequency of Th1 cells in peripheral blood mononuclear cells and bone marrow mononuclear cells from newly diagnosed B-ALL patients compared with healthy donors. Furthermore, increased levels of Th17-related cytokines including IL-17, IL-21, IL-23, IL-1β, and IL-6 were presented in between blood and marrow in B-ALL patients. Both IL-17A and IL-21, two Th17-secreted cytokines, induced the proliferation of B-ALL cell line Nalm-6 and patient B-ALL cells isolated from B-ALL patients, herein either cytokine led to the phosphorylation of Akt and Stat3. Additionally, IL-17A promoted resistance to daunorubicin via activation of Akt signaling and the PI3K/Akt inhibitor LY294002 or perifosine almost completely rescued daunorubicin-induced cell death in B-ALL cells.
CONCLUSIONS
Our findings suggest that elevated Th17 cells secrete IL-17A by which promotes the proliferation and resistance to daunorubicin in B-ALL cells through activation of Akt signaling. Th17 cells may represent a novel target to improve B-ALL immunotherapy.
Topics: Adolescent; Adult; Aged; Cell Proliferation; Cell Separation; Daunorubicin; Drug Resistance, Neoplasm; Enzyme Activation; Humans; Interleukin-17; Interleukins; Middle Aged; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Proto-Oncogene Proteins c-akt; STAT3 Transcription Factor; Signal Transduction; Th1 Cells; Th17 Cells; Young Adult
PubMed: 27176825
DOI: 10.1186/s12967-016-0894-9