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Sample records for 3-kinase pi3k-akt pathway

  1. Targeting the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway: an emerging treatment strategy for squamous cell lung carcinoma.

    PubMed

    Beck, Joseph Thaddeus; Ismail, Amen; Tolomeo, Christina

    2014-09-01

    Squamous cell lung carcinoma accounts for approximately 30% of all non-small cell lung cancers (NSCLCs). Despite progress in the understanding of the biology of cancer, cytotoxic chemotherapy remains the standard of care for patients with squamous cell lung carcinoma, but the prognosis is generally poor. The phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway is one of the most commonly activated signaling pathways in cancer, leading to cell proliferation, survival, and differentiation. It has therefore become a major focus of clinical research. Various alterations in the PI3K/AKT/mTOR pathway have been identified in squamous cell lung carcinoma and a number of agents targeting these alterations are in clinical development for use as single agents and in combination with other targeted and conventional treatments. These include pan-PI3K inhibitors, isoform-specific PI3K inhibitors, AKT inhibitors, mTOR inhibitors, and dual PI3K/mTOR inhibitors. These agents have demonstrated antitumor activity in preclinical models of NSCLC and preliminary clinical evidence is also available for some agents. This review will discuss the role of the PI3K/AKT/mTOR pathway in cancer and how the discovery of genetic alterations in this pathway in patients with squamous cell lung carcinoma can inform the development of targeted therapies for this disease. An overview of ongoing clinical trials investigating PI3K/AKT/mTOR pathway inhibitors in squamous cell lung carcinoma will also be included.

  2. PI3K/Akt signalling pathway and cancer.

    PubMed

    Fresno Vara, Juan Angel; Casado, Enrique; de Castro, Javier; Cejas, Paloma; Belda-Iniesta, Cristóbal; González-Barón, Manuel

    2004-04-01

    Phosphatidylinositol-3 kinases, PI3Ks, constitute a lipid kinase family characterized by their ability to phosphorylate inositol ring 3'-OH group in inositol phospholipids to generate the second messenger phosphatidylinositol-3,4,5-trisphosphate (PI-3,4,5-P(3)). RPTK activation results in PI(3,4,5)P(3) and PI(3,4)P(2) production by PI3K at the inner side of the plasma membrane. Akt interacts with these phospholipids, causing its translocation to the inner membrane, where it is phosphorylated and activated by PDK1 and PDK2. Activated Akt modulates the function of numerous substrates involved in the regulation of cell survival, cell cycle progression and cellular growth. In recent years, it has been shown that PI3K/Akt signalling pathway components are frequently altered in human cancers. Cancer treatment by chemotherapy and gamma-irradiation kills target cells primarily by the induction of apoptosis. However, the development of resistance to therapy is an important clinical problem. Failure to activate the apoptotic programme represents an important mode of drug resistance in tumor cells. Survival signals induced by several receptors are mediated mainly by PI3K/Akt, hence this pathway may decisively contribute to the resistant phenotype. Many of the signalling pathways involved in cellular transformation have been elucidated and efforts are underway to develop treatment strategies that target these specific signalling molecules or their downstream effectors. The PI3K/Akt pathway is involved in many of the mechanisms targeted by these new drugs, thus a better understanding of this crossroad can help to fully exploit the potential benefits of these new agents. PMID:15023437

  3. Berberine Induced Apoptosis of Human Osteosarcoma Cells by Inhibiting Phosphoinositide 3 Kinase/Protein Kinase B (PI3K/Akt) Signal Pathway Activation

    PubMed Central

    2016-01-01

    Background: Osteosarcoma is a malignant tumor with high mortality but effective therapy has not yet been developed. Berberine, an isoquinoline alkaloid component in several Chinese herbs including Huanglian, has been shown to induce growth inhibition and the apoptosis of certain cancer cells. The aim of this study was to determine the role of berberine on human osteosarcoma cell lines U2OS and its potential mechanism. Methods: The proliferation effect of U20S was exanimed by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di- phenytetrazoliumromide (MTT) and the percentage of apoptotic cells were determined by flow cytometric analysis. The expression of PI3K, p-Akt, Bax, Bcl-2, cleavage-PARP and Caspase3 were detected by Western blott. Results: Berberine treatment caused dose-dependent inhibiting proliferation and inducing apoptosis of U20S cell. Mechanistically, berberine inhibits PI3K/AKT activation that, in turn, results in up-regulating the expression of Bax, and PARP and down-regulating the expression of Bcl-2 and caspase3. In all, berberine can suppress the proliferation and induce the apoptosis of U2OS cell through inhibiting the PI3K/Akt signaling pathway activation. Conclusion: Berberine can suppress the proliferation and induce the apoptosis of U2OS cell through inhibiting the PI3K/Akt signaling pathway activation. PMID:27398330

  4. RhoC promotes human melanoma invasion in a PI3K/Akt-dependent pathway.

    PubMed

    Ruth, Mariah C; Xu, Yisheng; Maxwell, Ian H; Ahn, Natalie G; Norris, David A; Shellman, Yiqun G

    2006-04-01

    Overexpression of the small GTPase, RhoC, in various human cancers has been correlated with high metastatic ability and poor prognosis. Rho-kinase (ROCK) is an important effector of Rho GTPases. The oncogenic serine/threonine kinase Akt (also known as PKB) is a downstream effector of phosphatidylinositol-3 kinase (PI3K). Akt activation contributes to the neoplastic phenotype by promoting cell cycle progression, increasing antiapoptotic functions, and enhancing tumor cell invasion. Rho signaling via ROCK has been previously shown either to activate or to downregulate PI3K/Akt. Using a human radial growth phase melanoma cell line, WM35, we have established stable transfectants that overexpress RhoC (called WM35RhoC). We found that overexpression of RhoC increased phosphorylated-Akt (Ser473/474/472, pAkt) expression and promoted cell invasion. Inhibition of RhoC with C3 transferase downregulated pAkt expression and decreased cell invasion in these cells. In addition, inhibition of PI3K, Akt, or ROCK partially decreased invasion. Further, inhibition of PI3K but not ROCK decreased the pAkt level. These results suggest that RhoC promotes invasion in part via activation of a PI3K/Akt pathway, in a manner independent of ROCK signaling. We propose that RhoC promotes melanoma progression via separate mechanisms that regulate the PI3K/Akt pathway and the ROCK signaling pathway.

  5. PI3K-Akt pathway: its functions and alterations in human cancer.

    PubMed

    Osaki, M; Oshimura, M; Ito, H

    2004-11-01

    Phosphatidylinositol-3-kinase (PI3K) is a lipid kinase and generates phosphatidylinositol-3,4,5-trisphosphate (PI(3, 4, 5)P3). PI(3, 4, 5)P3 is a second messenger essential for the translocation of Akt to the plasma membrane where it is phosphorylated and activated by phosphoinositide-dependent kinase (PDK) 1 and PDK2. Activation of Akt plays a pivotal role in fundamental cellular functions such as cell proliferation and survival by phosphorylating a variety of substrates. In recent years, it has been reported that alterations to the PI3K-Akt signaling pathway are frequent in human cancer. Constitutive activation of the PI3K-Akt pathway occurs due to amplification of the PIK3C gene encoding PI3K or the Akt gene, or as a result of mutations in components of the pathway, for example PTEN (phosphatase and tensin homologue deleted on chromosome 10), which inhibit the activation of Akt. Several small molecules designed to specifically target PI3K-Akt have been developed, and induced cell cycle arrest or apoptosis in human cancer cells in vitro and in vivo . Moreover, the combination of an inhibitor with various cytotoxic agents enhances the anti-tumor efficacy. Therefore, specific inhibition of the activation of Akt may be a valid approach to treating human malignancies and overcoming the resistance of cancer cells to radiation or chemotherapy. PMID:15505410

  6. Insulin inhibits inflammation and promotes atherosclerotic plaque stability via PI3K-Akt pathway activation.

    PubMed

    Yan, Hao; Ma, Ying; Li, Yan; Zheng, Xiaohui; Lv, Ping; Zhang, Yuan; Li, Jia; Ma, Meijuan; Zhang, Le; Li, Congye; Zhang, Rongqing; Gao, Feng; Wang, Haichang; Tao, Ling

    2016-02-01

    Toll-like receptor (TLR) 4 induced inflammation was reported to play an important role in atherosclerotic plaque stability. Recent studies indicated that insulin could inhibit inflammation by activating phosphatidylinositol 3-kinase-Akt-dependent (PI3K-Akt) signaling pathway. In the current study, we hypothesized that insulin would inhibit TLR4 induced inflammation via promoting PI3K-Akt activation, thus enhancing the stabilization of atherosclerotic plaques. In order to mimic the process of plaque formation, monocyte-macrophage lineage RAW264.7 were cultured and induced to form foam cells by oxidized LDL (ox-LDL). Oil red O staining results showed that insulin significantly restrained ox-LDL-induced foam cell formation. Analysis of inflammatory reaction during foam cell formation indicated that insulin significantly down-regulated the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6 levels, inhibited TLR4, myeloid differentiation primary response gene (MyD) 88 and nuclear factor (NF)-κB. Further mechanism analysis showed that pretreating with the PI3K blocker, wortmannin dramatically dampened the insulin-induced up-regulation of pAkt expression. Additionally, blockade of PI3K-Akt signaling also dampened the immunosuppression effect brought by insulin. Following the construction of a rodent atherosclerosis model, pretreatment of insulin resulted in an evident decrease in lipid deposition of the blood vessel wall, serum levels of TNF-α and IL-6, and numbers of infiltrated macrophages and foam cells. Taken together, these results suggested that insulin might inhibit inflammation and promote atherosclerotic plaque stability via the PI3K-Akt pathway by targeting TLR4-MyD88-NF-κB signaling. Our findings may provide a potential target for the prevention of cardiovascular disease. PMID:26681144

  7. The PI3K/AKT Pathway as a Target for Cancer Treatment.

    PubMed

    Mayer, Ingrid A; Arteaga, Carlos L

    2016-01-01

    Anticancer targeted therapies are designed to exploit a particular vulnerability in the tumor, which in most cases results from its dependence on an oncogene and/or loss of a tumor suppressor. Genes in the phosphoinositide 3-kinase (PI3K)/AKT pathway are the most frequently altered in human cancers. Aberrant activation of this pathway, as a result of these somatic alterations, is associated with cellular transformation, tumorigenesis, cancer progression, and drug resistance. Several drugs targeting PI3K/ATK are currently in clinical trials, alone or in combination, in both solid tumors and hematologic malignancies. These drugs are the focus of this review.

  8. Infectious bursal disease virus activates the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway by interaction of VP5 protein with the p85{alpha} subunit of PI3K

    SciTech Connect

    Wei Li; Hou Lei; Zhu Shanshan; Wang Jing; Zhou Jiao; Liu Jue

    2011-08-15

    Phosphatidylinositol 3-kinase (PI3K)/Akt signaling is commonly activated upon virus infection and has been implicated in the regulation of diverse cellular functions such as proliferation and apoptosis. The present study demonstrated for the first time that infectious bursal disease virus (IBDV), the causative agent of a highly contagious disease in chickens, can induce Akt phosphorylation in cultured cells, by a mechanism that is dependent on PI3K. Inhibition of PI3K activation greatly enhanced virus-induced cytopathic effect and apoptotic cell death as evidenced by cleavage of poly-ADP ribose polymerase and activation of caspase-3. Investigations into the mechanism of PI3K/Akt activation revealed that IBDV activates PI3K/Akt signaling through binding of the non-structural protein VP5 to regulatory subunit p85{alpha} of PI3K resulting in the suppression of premature apoptosis and improved virus growth after infection. The results presented here provide a basis for understanding molecular mechanism of IBDV infection.

  9. Aged black garlic extract inhibits HT29 colon cancer cell growth via the PI3K/Akt signaling pathway.

    PubMed

    Dong, Menghua; Yang, Guiqing; Liu, Hanchen; Liu, Xiaoxu; Lin, Sixiang; Sun, Dongning; Wang, Yishan

    2014-03-01

    Accumulating evidence indicates that aged black garlic extract (ABGE) may prove beneficial in preventing or inhibiting oncogenesis; however, the underlying mechanisms have not been fully elucidated. The present study aimed to investigate the effects of ABGE on the proliferation and apoptosis of HT29 colon cancer cells. Our results demonstrated that ABGE inhibited HT29 cell growth via the induction of apoptosis and cell cycle arrest. We further investigated the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signal transduction pathway and the molecular mechanisms underlying the ABGE-induced inhibition of HT29 cell proliferation. We observed that ABGE may regulate the function of the PI3K/Akt pathway through upregulating PTEN and downregulating Akt and p-Akt expression, as well as suppressing its downstream target, 70-kDa ribosomal protein S6 kinase 1, at the mRNA and protein levels. In conclusion, these findings suggest that the PI3K/Akt signal transduction pathway is crucial for the development of colon cancer. ABGE inhibited the growth and induced apoptosis in HT29 cells through the inhibition of the PI3K/Akt pathway, suggesting that ABGE may be effective in the prevention and treatment of colon cancer in humans. PMID:24649105

  10. The PI3K/Akt Pathway in Tumors of Endocrine Tissues

    PubMed Central

    Robbins, Helen Louise; Hague, Angela

    2016-01-01

    The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is a key driver in carcinogenesis. Defects in this pathway in human cancer syndromes such as Cowden’s disease and Multiple Endocrine Neoplasia result in tumors of endocrine tissues, highlighting its importance in these cancer types. This review explores the growing evidence from multiple animal and in vitro models and from analysis of human tumors for the involvement of this pathway in the following: thyroid carcinoma subtypes, parathyroid carcinoma, pituitary tumors, adrenocortical carcinoma, phaeochromocytoma, neuroblastoma, and gastroenteropancreatic neuroendocrine tumors. While data are not always consistent, immunohistochemistry performed on human tumor tissue has been used alongside other techniques to demonstrate Akt overactivation. We review active Akt as a potential prognostic marker and the PI3K pathway as a therapeutic target in endocrine neoplasia. PMID:26793165

  11. DAB2IP coordinates both PI3K-Akt and ASK1 pathways for cell survival and apoptosis

    PubMed Central

    Xie, Daxing; Gore, Crystal; Zhou, Jian; Pong, Rey-Chen; Zhang, Haifeng; Yu, Luyang; Vessella, Robert L.; Min, Wang; Hsieh, Jer-Tsong

    2009-01-01

    In metastatic prostate cancer (PCa) cells, imbalance between cell survival and death signals such as constitutive activation of phosphatidylinositol 3-kinase (PI3K)-Akt and inactivation of apoptosis-stimulated kinase (ASK1)-JNK pathways is often detected. Here, we show that DAB2IP protein, often down-regulated in PCa, is a potent growth inhibitor by inducing G0/G1 cell cycle arrest and is proapoptotic in response to stress. Gain of function study showed that DAB2IP can suppress the PI3K-Akt pathway and enhance ASK1 activation leading to cell apoptosis, whereas loss of DAB2IP expression resulted in PI3K-Akt activation and ASK1-JNK inactivation leading to accelerated PCa growth in vivo. Moreover, glandular epithelia from DAB2IP−/− animal exhibited hyperplasia and apoptotic defect. Structural functional analyses of DAB2IP protein indicate that both proline-rich (PR) and PERIOD-like (PER) domains, in addition to the critical role of C2 domain in ASK1 activity, are important for modulating PI3K-Akt activity. Thus, DAB2IP is a scaffold protein capable of bridging both survival and death signal molecules, which implies its role in maintaining cell homeostasis. PMID:19903888

  12. Ganoderma atrum polysaccharide improves aortic relaxation in diabetic rats via PI3K/Akt pathway.

    PubMed

    Zhu, Ke-Xue; Nie, Shao-Ping; Li, Chuan; Gong, Deming; Xie, Ming-Yong

    2014-03-15

    A newly identified polysaccharide (PSG-1) has been purified from Ganoderma atrum. The study was to investigate the protective effect of PSG-1 on diabetes-induced endothelial dysfunction in rat aorta. Rats were fed a high fat diet for 8 weeks and then injected with a low dose of streptozotocin to induce type 2 diabetes. The diabetic rats were orally treated with PSG-1 for 4 weeks. It was found that administration of PSG-1 significantly reduced levels of fasting blood glucose, improved endothelium-dependent aortic relaxation, increased levels of phosphoinositide 3-kinase (PI3K), phospho-Akt (p-Akt), endothelial nitric oxide synthase (eNOS) and nitric oxide in the aorta from diabetic rats, compared to un-treated diabetics. These results suggested that the protective effects of PSG-1 against endothelial dysfunction may be related to activation of the PI3K/Akt/eNOS pathway.

  13. PI3K/AKT Signaling Pathway Is Essential for Survival of Induced Pluripotent Stem Cells

    PubMed Central

    Hossini, Amir M.; Quast, Annika S.; Plötz, Michael; Grauel, Katharina; Exner, Tarik; Küchler, Judit; Stachelscheid, Harald; Eberle, Jürgen; Rabien, Anja

    2016-01-01

    Apoptosis is a highly conserved biochemical mechanism which is tightly controlled in cells. It contributes to maintenance of tissue homeostasis and normally eliminates highly proliferative cells with malignant properties. Induced pluripotent stem cells (iPSCs) have recently been described with significant functional and morphological similarities to embryonic stem cells. Human iPSCs are of great hope for regenerative medicine due to their broad potential to differentiate into specialized cell types in culture. They may be useful for exploring disease mechanisms and may provide the basis for future cell-based replacement therapies. However, there is only poor insight into iPSCs cell signaling as the regulation of apoptosis. In this study, we focused our attention on the apoptotic response of Alzheimer fibroblast-derived iPSCs and two other Alzheimer free iPSCs to five biologically relevant kinase inhibitors as well as to the death ligand TRAIL. To our knowledge, we are the first to report that the relatively high basal apoptotic rate of iPSCs is strongly suppressed by the pancaspase inhibitor QVD-Oph, thus underlining the dependency on proapoptotic caspase cascades. Furthermore, wortmannin, an inhibitor of phosphoinositid-3 kinase / Akt signaling (PI3K-AKT), dramatically and rapidly induced apoptosis in iPSCs. In contrast, parental fibroblasts as well as iPSC-derived neuronal cells were not responsive. The resulting condensation and fragmentation of DNA and decrease of the membrane potential are typical features of apoptosis. Comparable effects were observed with an AKT inhibitor (MK-2206). Wortmannin resulted in disappearance of phosphorylated AKT and activation of the main effector caspase-3 in iPSCs. These results clearly demonstrate for the first time that PI3K-AKT represents a highly essential survival signaling pathway in iPSCs. The findings provide improved understanding on the underlying mechanisms of apoptosis regulation in iPSCs. PMID:27138223

  14. Targeting the PI3K/Akt signaling pathway in gastric carcinoma: A reality for personalized medicine?

    PubMed Central

    Singh, Shikha Satendra; Yap, Wei Ney; Arfuso, Frank; Kar, Shreya; Wang, Chao; Cai, Wanpei; Dharmarajan, Arunasalam M; Sethi, Gautam; Kumar, Alan Prem

    2015-01-01

    Frequent activation of phosphatidylinositol-3 kinases (PI3K)/Akt/mTOR signaling pathway in gastric cancer (GC) is gaining immense popularity with identification of mutations and/or amplifications of PIK3CA gene or loss of function of PTEN, a tumor suppressor protein, to name a few; both playing a crucial role in regulating this pathway. These aberrations result in dysregulation of this pathway eventually leading to gastric oncogenesis, hence, there is a need for targeted therapy for more effective anticancer treatment. Several inhibitors are currently in either preclinical or clinical stages for treatment of solid tumors like GC. With so many inhibitors under development, further studies on predictive biomarkers are needed to measure the specificity of any therapeutic intervention. Herein, we review the common dysregulation of PI3K/Akt/mTOR pathway in GC and the various types of single or dual pathway inhibitors under development that might have a superior role in GC treatment. We also summarize the recent developments in identification of predictive biomarkers and propose use of predictive biomarkers to facilitate more personalized cancer therapy with effective PI3K/Akt/mTOR pathway inhibition. PMID:26604635

  15. Nerve growth factor (NGF) regulates activity of nuclear factor of activated T-cells (NFAT) in neurons via the phosphatidylinositol 3-kinase (PI3K)-Akt-glycogen synthase kinase 3β (GSK3β) pathway.

    PubMed

    Kim, Man-Su; Shutov, Leonid P; Gnanasekaran, Aswini; Lin, Zhihong; Rysted, Jacob E; Ulrich, Jason D; Usachev, Yuriy M

    2014-11-01

    The Ca(2+)/calcineurin-dependent transcription factor nuclear factor of activated T-cells (NFAT) plays an important role in regulating many neuronal functions, including excitability, axonal growth, synaptogenesis, and neuronal survival. NFAT can be activated by action potential firing or depolarization that leads to Ca(2+)/calcineurin-dependent dephosphorylation of NFAT and its translocation to the nucleus. Recent data suggest that NFAT and NFAT-dependent functions in neurons can also be potently regulated by NGF and other neurotrophins. However, the mechanisms of NFAT regulation by neurotrophins are not well understood. Here, we show that in dorsal root ganglion sensory neurons, NGF markedly facilitates NFAT-mediated gene expression induced by mild depolarization. The effects of NGF were not associated with changes in [Ca(2+)]i and were independent of phospholipase C activity. Instead, the facilitatory effect of NGF depended on activation of the PI3K/Akt pathway downstream of the TrkA receptor and on inhibition of glycogen synthase kinase 3β (GSK3β), a protein kinase known to phosphorylate NFAT and promote its nuclear export. Knockdown or knockout of NFATc3 eliminated this facilitatory effect. Simultaneous monitoring of EGFP-NFATc3 nuclear translocation and [Ca(2+)]i changes in dorsal root ganglion neurons indicated that NGF slowed the rate of NFATc3 nuclear export but did not affect its nuclear import rate. Collectively, our data suggest that NGF facilitates depolarization-induced NFAT activation by stimulating PI3K/Akt signaling, inactivating GSK3β, and thereby slowing NFATc3 export from the nucleus. We propose that NFAT serves as an integrator of neurotrophin action and depolarization-driven calcium signaling to regulate neuronal gene expression.

  16. PI-103 and Quercetin Attenuate PI3K-AKT Signaling Pathway in T- Cell Lymphoma Exposed to Hydrogen Peroxide.

    PubMed

    Maurya, Akhilendra Kumar; Vinayak, Manjula

    2016-01-01

    Phosphatidylinositol 3 kinase-protein kinase B (PI3K-AKT) pathway has been considered as major drug target site due to its frequent activation in cancer. AKT regulates the activity of various targets to promote tumorigenesis and metastasis. Accumulation of reactive oxygen species (ROS) has been linked to oxidative stress and regulation of signaling pathways for metabolic adaptation of tumor microenvironment. Hydrogen peroxide (H2O2) in this context is used as ROS source for oxidative stress preconditioning. Antioxidants are commonly considered to be beneficial to reduce detrimental effects of ROS and are recommended as dietary supplements. Quercetin, a ubiquitous bioactive flavonoid is a dietary component which has attracted much of interest due to its potential health-promoting effects. Present study is aimed to analyze PI3K-AKT signaling pathway in H2O2 exposed Dalton's lymphoma ascite (DLA) cells. Further, regulation of PI3K-AKT pathway by quercetin as well as PI-103, an inhibitor of PI3K was analyzed. Exposure of H2O2 (1mM H2O2 for 30min) to DLA cells caused ROS accumulation and resulted in increased phosphorylation of PI3K and downstream proteins PDK1 and AKT (Ser-473 and Thr-308), cell survival factors BAD and ERK1/2, as well as TNFR1. However, level of tumor suppressor PTEN was declined. Both PI-103 & quercetin suppressed the enhanced level of ROS and significantly down-regulated phosphorylation of AKT, PDK1, BAD and level of TNFR1 as well as increased the level of PTEN in H2O2 induced lymphoma cells. The overall result suggests that quercetin and PI3K inhibitor PI-103 attenuate PI3K-AKT pathway in a similar mechanism. PMID:27494022

  17. Modulatory effects of yerba maté (Ilex paraguariensis) on the PI3K-AKT signaling pathway.

    PubMed

    Arçari, Demétrius Paiva; Santos, Juliana Carvalho; Gambero, Alessandra; Ferraz, Lucio Fábio Caldas; Ribeiro, Marcelo Lima

    2013-10-01

    The aim of this study was to evaluate the effects of yerba maté (YM) extract on the phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway in vivo. The mice were introduced to either standard- or high-fat diet (HFD). After 8 weeks on an HFD, mice were randomly assigned to one of the two treatment conditions, water or yerba maté extract at 1.0 g/kg. After treatment, glucose blood level and hepatic insulin response were evaluated. Liver tissue was examined to determine the mRNA levels using the PI3K-AKT PCR array. The nuclear translocation of forkhead box O1 (FOXO1) was determined by an electrophoretic mobility-shift assay. Our data demonstrated that yerba maté extract significantly decreased the final body weight, glucose blood levels, and insulin resistance of mice. Molecular analysis demonstrated that an HFD downregulated Akt2, Irs1, Irs2, Pi3kca, Pi3kcg, and Pdk1; after yerba maté treatment, the levels of those genes returned to baseline. In addition, an HFD upregulated Pepck and G6pc and increased FOXO1 nuclear translocation. The intervention downregulated these genes by decreasing FOXO1 nuclear translocation. The results obtained demonstrate for the first time the specific action of yerba maté on the PI3K-AKT pathway, which contributed to the observed improvement in hepatic insulin signaling.

  18. Eupatilin induces human renal cancer cell apoptosis via ROS-mediated MAPK and PI3K/AKT signaling pathways

    PubMed Central

    Zhong, Wei-Feng; Wang, Xiao-Hong; Pan, Bin; Li, Feng; Kuang, Lu; Su, Ze-Xuan

    2016-01-01

    Phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen activated protein kinase (MAPK) signaling cascades have significant roles in cell proliferation, survival, angiogenesis and metastasis of tumor cells. Eupatilin, one of the major compounds present in Artemisia species, has been demonstrated to have antitumor properties. However, the effect of eupatilin in renal cell carcinoma (RCC) remains to be elucidated. Therefore, the present study investigated the biological effects and mechanisms of eupatilin in RCC cell apoptosis. The results of the present study demonstrated that eupatilin significantly induced cell apoptosis and enhanced the production of reactive oxygen species (ROS) in 786-O cells. In addition, eupatilin induced phosphorylation of p38α (Thr180/Tyr182), extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase 1/2 (Thr183/Tyr185), and decreased the phosphorylation of PI3K and AKT in 786-O cells in a concentration-dependent manner. Furthermore, the ROS inhibitor N-acetyl-L-cysteine was able to rescue the MAPK activation and PI3K/AKT inhibition induced by eupatilin. Taken together, the results of the present study provide evidence that inhibition of eupatilin induces apoptosis in human RCC via ROS-mediated activation of the MAPK signaling pathway and inhibition of the PI3K/AKT signaling pathway. Thus, eupatilin may serve as a potential therapeutic agent for the treatment of human RCC. PMID:27698876

  19. Eupatilin induces human renal cancer cell apoptosis via ROS-mediated MAPK and PI3K/AKT signaling pathways

    PubMed Central

    Zhong, Wei-Feng; Wang, Xiao-Hong; Pan, Bin; Li, Feng; Kuang, Lu; Su, Ze-Xuan

    2016-01-01

    Phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen activated protein kinase (MAPK) signaling cascades have significant roles in cell proliferation, survival, angiogenesis and metastasis of tumor cells. Eupatilin, one of the major compounds present in Artemisia species, has been demonstrated to have antitumor properties. However, the effect of eupatilin in renal cell carcinoma (RCC) remains to be elucidated. Therefore, the present study investigated the biological effects and mechanisms of eupatilin in RCC cell apoptosis. The results of the present study demonstrated that eupatilin significantly induced cell apoptosis and enhanced the production of reactive oxygen species (ROS) in 786-O cells. In addition, eupatilin induced phosphorylation of p38α (Thr180/Tyr182), extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase 1/2 (Thr183/Tyr185), and decreased the phosphorylation of PI3K and AKT in 786-O cells in a concentration-dependent manner. Furthermore, the ROS inhibitor N-acetyl-L-cysteine was able to rescue the MAPK activation and PI3K/AKT inhibition induced by eupatilin. Taken together, the results of the present study provide evidence that inhibition of eupatilin induces apoptosis in human RCC via ROS-mediated activation of the MAPK signaling pathway and inhibition of the PI3K/AKT signaling pathway. Thus, eupatilin may serve as a potential therapeutic agent for the treatment of human RCC.

  20. PI3K/Akt/mTOR signaling pathway in cancer stem cells: from basic research to clinical application

    PubMed Central

    Xia, Pu; Xu, Xiao-Yan

    2015-01-01

    Cancer stem cells (CSCs) are a subpopulation of tumor cells that possess unique self-renewal activity and mediate tumor initiation and propagation. The PI3K/Akt/mTOR signaling pathway can be considered as a master regulator for cancer. More and more recent studies have shown the links between PI3K/Akt/mTOR signaling pathway and CSC biology. Herein, we provide a comprehensive review on the role of signaling components upstream and downstream of PI3K/Akt/mTOR signaling in CSC. In addition, we also summarize various classes of small molecule inhibitors of PI3K/Akt/mTOR signaling pathway and their clinical potential in CSC. Overall, the current available data suggest that the PI3K/Akt/mTOR signaling pathway could be a promising target for development of CSC-target drugs. PMID:26175931

  1. EMP-1 promotes tumorigenesis of NSCLC through PI3K/AKT pathway.

    PubMed

    Lai, Senyan; Wang, Guihua; Cao, Xiaonian; Li, Zhaoming; Hu, Junbo; Wang, Jing

    2012-12-01

    This study examined the role of EMP-1 in tumorigenesis of non-small cell lung carcinoma (NSCLC) and the possible mechanism. Specimens were collected from 28 patients with benign lung diseases and 28 with NSCLC, and immunohistochemically detected to evaluate the correlation of EMP-1 expression to the clinical features of NSCLC. Recombinant adenovirus was constructed to over-express EMP-1 and then infect PC9 cells. Cell proliferation was measured by Ki67 staining. Western blotting was performed to examine the effect of EMP-1 on the PI3K/AKT signaling. Moreover, tumor xenografts were established by subcutaneous injection of PC9 cell suspension (about 5×10(7)/mL in 100 μL of PBS) into the right hind limbs of athymic nude mice. The results showed EMP-1 was significantly up-regulated in NSCLC patients as compared with those with benign lung diseases. Over-expression of EMP-1 promoted proliferation of PC9 cells, which coincided with the activation of the PI3K/AKT pathway. EMP-1 promoted the growth of xenografts of PC9 cells in athymic nude mice. It was concluded that EMP-1 expression may contribute to the development and progress of NSCLC by activating PI3K/AKT pathway.

  2. PTEN Contributes to Profound PI3K/Akt Signaling Pathway Deregulation in Dystrophin-Deficient Dog Muscle

    PubMed Central

    Feron, Marie; Guevel, Laetitia; Rouger, Karl; Dubreil, Laurence; Arnaud, Marie-Claire; Ledevin, Mireille; Megeney, Lynn A.; Cherel, Yan; Sakanyan, Vehary

    2009-01-01

    Duchenne muscular dystrophy is the most common and severe form of muscular dystrophy, and although the genetic basis of this disease is well defined, the overall mechanisms that define its pathogenesis remain obscure. Alterations in individual signaling pathways have been described, but little information is available regarding their putative implications in Duchenne muscular dystrophy pathogenesis. Here, we studied the status of various major signaling pathways in the Golden Retriever muscular dystrophy dog that specifically reproduces the full spectrum of human pathology. Using antibody arrays, we found that Akt1, glycogen synthase kinase-3β (GSK3β), 70-kDa ribosomal protein S6 kinase (p70S6K), extracellular signal-regulated kinases 1/2, and p38δ and p38γ kinases all exhibited decreased phosphorylation in muscle from a 4-month-old animal with Golden Retriever muscular dystrophy, revealing a deep alteration of the phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase pathways. Immunohistochemistry analysis revealed the presence of muscle fibers exhibiting a cytosolic accumulation of Akt1, GSK3β, and phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase (PTEN), an enzyme counteracting PI3K-mediated Akt activation. Enzymatic assays established that these alterations in phosphorylation and expression levels were associated with decreased Akt and increased GSK3β and PTEN activities. PTEN/GSK3β-positive fibers were also observed in muscle sections from 3- and 36-month-old animals, indicating long-term PI3K/Akt pathway alteration. Collectively, our data suggest that increased PTEN expression and activity play a central role in PI3K/Akt/GSK3β and p70S6K pathway modulation, which could exacerbate the consequences of dystrophin deficiency. PMID:19264909

  3. Activation of the PI3K/AKT pathway correlates with prognosis in stage II colon cancer

    PubMed Central

    Malinowsky, K; Nitsche, U; Janssen, K-P; Bader, F G; Späth, C; Drecoll, E; Keller, G; Höfler, H; Slotta-Huspenina, J; Becker, K-F

    2014-01-01

    Background: Patients with UICC/AJCC stage II colon cancer have a high 5-year overall survival rate after surgery. Nevertheless, a significant subgroup of patients develops tumour recurrence. Currently, there are no clinically established biomarkers available to identify this patient group. We applied reverse-phase protein arrays (RPPA) for phosphatidylinositide-3-kinase pathway activation mapping to stratify patients according to their risk of tumour recurrence after surgery. Methods: Full-length proteins were extracted from formalin-fixed, paraffin-embedded tissue samples of 118 patients who underwent curative resection. RPPA technology was used to analyse expression and/or phosphorylation levels of six major factors of the phosphatidylinositide-3-kinase pathway. Oncogenic mutations of KRAS and BRAF, and DNA microsatellite status, currently discussed as prognostic markers, were analysed in parallel. Results: Expression of phospho-AKT (HR=3.52; P=0.032), S6RP (HR=6.3; P=0.044), and phospho-4E-BP1 (HR=4.12; P=0.011) were prognostic factors for disease-free survival. None of the molecular genetic alterations were significantly associated with prognosis. Conclusions: Our data indicate that activation of the PI3K/AKT pathway evidenced on the protein level might be a valuable prognostic marker to stratify patients for their risk of tumour recurrence. Beside adjuvant chemotherapy targeting of upregulated PI3K/AKT signalling may be an attractive strategy for treatment of high-risk patients. PMID:24619078

  4. Gefitinib induces lung cancer cell autophagy and apoptosis via blockade of the PI3K/AKT/mTOR pathway

    PubMed Central

    ZHAO, ZHONG-QUAN; YU, ZHONG-YANG; LI, JIE; OUYANG, XUE-NONG

    2016-01-01

    Gefitinib is a selective inhibitor of the tyrosine kinase epidermal growth factor receptor, which inhibits tumor pathogenesis, metastasis and angiogenesis, as well as promoting apoptosis. Therefore, gefitinib presents an effective drug for the targeted therapy of lung cancer. However, the underlying mechanisms by which gefitinib induces lung cancer cell death remain unclear. To investigate the effects of gefitinib on lung cancer cells and the mechanism of such, the present study analyzed the effect of gefitinib on the autophagy, apoptosis and proliferation of the A549 and A549-gefitinib-resistant (GR) cell lines GR. The regulation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway was also investigated. Acridine orange staining revealed that gefitinib induced autophagy of A549 cells but not A549-GR cells. In addition, gefitinib promoted apoptosis and inhibited proliferation of A549 cells but not A549-GR cells. Furthermore, western blot analysis demonstrated that gefitinib treatment led to the downregulation of PI3K, AKT, pAKT, mTOR and phosphorylated-mTOR protein expression in A549 cells but not A549-GR cells. LY294002 blocked the PI3K/AKT/mTOR pathway and induced autophagy and apoptosis of A549 cells, however, no synergistic effect was observed following combined treatment with gefitinib and LY294002. In conclusion, the results of the present study indicate that gefitinib promotes autophagy and apoptosis of lung cancer cells via blockade of the PI3K/AKT/mTOR pathway, which leads to lung cancer cell death. PMID:27347100

  5. Progesterone is neuroprotective against ischemic brain injury through its effects on the PI3K/Akt signaling pathway

    PubMed Central

    Ishrat, Tauheed; Sayeed, Iqbal; Atif, Fahim; Hua, Fang; Stein, Donald G.

    2012-01-01

    We tested the hypothesis that the phosphatidylinositol-3 kinase (PI3K/Akt) pathway mediates some of the neuroprotective effects of progesterone (PROG) after ischemic stroke. We examined whether PROG acting through the PI3K/Akt pathway could affect the expression of vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF). Rats underwent permanent focal cerebral ischemia (pMCAO) by electro-coagulation and received intraperitoneal injections of PROG (8mg/kg) or vehicle at 1h post-occlusion and subcutaneous injections at 6, 24, and 48h. PAkt/Akt levels, apoptosis and apoptosis-related proteins (pBAD, BAD, caspase-3, and cleaved caspase-3) were analyzed by TUNEL assays, Western blotting and immunohistochemistry at 24h post-pMCAO. VEGF and BDNF were analyzed at 24, 72h and 14 days post-pMCAO with Western blots. Following pMCAO, PROG treatment significantly (p<0.05) reduced ischemic lesion size and edema. Treatment with PROG significantly (p<0.05) decreased VEGF at 24 and 72h but increased VEGF expression 14d after injury. The treatment also increased BDNF, and attenuated apoptosis by increasing Akt phosphorylation compared to vehicle-alone. The selective PI3K inhibitor Wortmannin compromised PROG-induced neuroprotective effects and reduced the elevation of pAkt levels in the ischemic penumbra. Our findings lead us to suggest that the PI3K/Akt pathway can play a role in mediating the neuroprotective effects of PROG after stroke by altering the expression of trophic factors in the brain. PMID:22450229

  6. Blocking the PI3K/AKT pathway enhances mammalian reovirus replication by repressing IFN-stimulated genes

    PubMed Central

    Tian, Jin; Zhang, Xiaozhan; Wu, Hongxia; Liu, Chunguo; Li, Zhijie; Hu, Xiaoliang; Su, Shuo; Wang, Lin-Fa; Qu, Liandong

    2015-01-01

    Many host cellular signaling pathways were activated and exploited by virus infection for more efficient replication. The PI3K/Akt pathway has recently attracted considerable interest due to its role in regulating virus replication. This study demonstrated for the first time that the mammalian reovirus strains Masked Palm Civet/China/2004 (MPC/04) and Bat/China/2003 (B/03) can induce transient activation of the PI3K/Akt pathway early in infection in vitro. When UV-treated, both viruses activated PI3K/Akt signaling, indicating that the virus/receptor interaction was sufficient to activate PI3K/Akt. Reovirus virions can use both clathrin- and caveolae-mediated endocytosis, but only chlorpromazine, a specific inhibitor of clathrin-mediated endocytosis, or siRNA targeting clathrin suppressed Akt phosphorylation. We also identified the upstream molecules of the PI3K pathway. Virus infection induced phosphorylation of focal adhesion kinase (FAK) but not Gab1, and blockage of FAK phosphorylation suppressed Akt phosphorylation. Blockage of PI3K/Akt activation increased virus RNA synthesis and viral yield. We also found that reovirus infection activated the IFN-stimulated response element (ISRE) in an interferon-independent manner and up-regulated IFN-stimulated genes (ISGs) via the PI3K/Akt/EMSY pathway. Suppression of PI3K/Akt activation impaired the induction of ISRE and down-regulated the expression of ISGs. Overexpression of ISG15 and Viperin inhibited virus replication, and knockdown of either enhanced virus replication. Collectively, these results demonstrate that PI3K/Akt activated by mammalian reovirus serves as a pathway for sensing and then inhibiting virus replication/infection. PMID:26388843

  7. PTEN regulates angiogenesis through PI3K/Akt/VEGF signaling pathway in human pancreatic cancer cells.

    PubMed

    Ma, Jiachi; Sawai, Hirozumi; Ochi, Nobuo; Matsuo, Yoichi; Xu, Donghui; Yasuda, Akira; Takahashi, Hiroki; Wakasugi, Takehiro; Takeyama, Hiromitsu

    2009-11-01

    Phosphoinositide 3-kinase (PI3K) pathway exerts its effects through Akt, its downstream target molecule, and thereby regulates various cell functions including cell proliferation, cell transformation, apoptosis, tumor growth, and angiogenesis. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) has been implicated in regulating cell survival signaling through the PI3K/Akt pathway. However, the mechanism by PI3K/PTEN signaling regulates angiogenesis and tumor growth in vivo remains to be elucidated. Vascular endothelial growth factor (VEGF) plays a pivotal role in tumor angiogenesis. The effect of PTEN on VEGF-mediated signal in pancreatic cancer is unknown. This study aimed to determine the effect of PTEN on both the expression of VEGF and angiogenesis. Toward that end, we used the siRNA knockdown method to specifically define the role of PTEN in the expression of VEGF and angiogenesis. We found that siRNA-mediated inhibition of PTEN gene expression in pancreatic cancer cells increase their VEGF secretion, up-modulated the proliferation, and migration of co-cultured vascular endothelial cell and enhanced tubule formation by HUVEC. In addition, PTEN modulated VEGF-mediated signaling and affected tumor angiogenesis through PI3K/Akt/VEGF/eNOS pathway.

  8. Fragile Histidine Triad (FHIT) Suppresses Proliferation and Promotes Apoptosis in Cholangiocarcinoma Cells by Blocking PI3K-Akt Pathway

    PubMed Central

    Huang, Qiang; Liu, Zhen; Xie, Fang; Liu, Chenhai; Shao, Feng; Zhu, Cheng-lin; Hu, Sanyuan

    2014-01-01

    Fragile histidine triad (FHIT) is a tumor suppressor protein that regulates cancer cell proliferation and apoptosis. However, its exact mechanism of action is poorly understood. Phosphatidylinositol 3-OH kinase (PI3K)-Akt-survivin is an important signaling pathway that was regulated by FHIT in lung cancer cells. To determine whether FHIT can regulate this pathway in cholangiocarcinoma QBC939 cells, we constructed an FHIT expression plasmid and used it to transfect QBC939 cells. Protein and mRNA expression were measured by western blotting and qRT-PCR, respectively. The viability and apoptosis of QBC939 cells were then assessed using MTT assays and flow cytometry. Our results revealed that the expression of survivin and Bcl-2 was downregulated, and caspase 3 was upregulated, in cells overexpressing FHIT. In addition, FHIT suppressed the phosphorylation of Akt. The changes in cell proliferation and apoptosis were obvious in cells overexpressing FHIT which parallels that of treatment with LY294002, a potent inhibitor of phosphoinositide 3-kinases. Treatment with LY294002 further decreased the expression of survivin and Bcl-2 and increased caspase-3 levels. These results suggest that FHIT can block the PI3K-Akt-survivin pathway by suppressing the phosphorylation of Akt and the expression of survivin and Bcl-2 and upregulating caspase 3. PMID:24757411

  9. Allosteric modulation of Ras and the PI3K/AKT/mTOR pathway: emerging therapeutic opportunities

    PubMed Central

    Hubbard, Paul A.; Moody, Colleen L.; Murali, Ramachandran

    2014-01-01

    GTPases and kinases are two predominant signaling modules that regulate cell fate. Dysregulation of Ras, a GTPase, and the three eponymous kinases that form key nodes of the associated phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3K)/AKT/mTOR pathway have been implicated in many cancers, including pancreatic cancer, a disease noted for its current lack of effective therapeutics. The K-Ras isoform of Ras is mutated in over 90% of pancreatic ductal adenocarcinomas (PDAC) and there is growing evidence linking aberrant PI3K/AKT/mTOR pathway activity to PDAC. Although these observations suggest that targeting one of these nodes might lead to more effective treatment options for patients with pancreatic and other cancers, the complex regulatory mechanisms and the number of sequence-conserved isoforms of these proteins have been viewed as significant barriers in drug development. Emerging insights into the allosteric regulatory mechanisms of these proteins suggest novel opportunities for development of selective allosteric inhibitors with fragment-based drug discovery (FBDD) helping make significant inroads. The fact that allosteric inhibitors of Ras and AKT are currently in pre-clinical development lends support to this approach. In this article, we will focus on the recent advances and merits of developing allosteric drugs targeting these two inter-related signaling pathways. PMID:25566081

  10. Allosteric modulation of Ras and the PI3K/AKT/mTOR pathway: emerging therapeutic opportunities.

    PubMed

    Hubbard, Paul A; Moody, Colleen L; Murali, Ramachandran

    2014-01-01

    GTPases and kinases are two predominant signaling modules that regulate cell fate. Dysregulation of Ras, a GTPase, and the three eponymous kinases that form key nodes of the associated phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3K)/AKT/mTOR pathway have been implicated in many cancers, including pancreatic cancer, a disease noted for its current lack of effective therapeutics. The K-Ras isoform of Ras is mutated in over 90% of pancreatic ductal adenocarcinomas (PDAC) and there is growing evidence linking aberrant PI3K/AKT/mTOR pathway activity to PDAC. Although these observations suggest that targeting one of these nodes might lead to more effective treatment options for patients with pancreatic and other cancers, the complex regulatory mechanisms and the number of sequence-conserved isoforms of these proteins have been viewed as significant barriers in drug development. Emerging insights into the allosteric regulatory mechanisms of these proteins suggest novel opportunities for development of selective allosteric inhibitors with fragment-based drug discovery (FBDD) helping make significant inroads. The fact that allosteric inhibitors of Ras and AKT are currently in pre-clinical development lends support to this approach. In this article, we will focus on the recent advances and merits of developing allosteric drugs targeting these two inter-related signaling pathways. PMID:25566081

  11. Metabolic Reprogramming by the PI3K-Akt-mTOR Pathway in Cancer.

    PubMed

    Lien, Evan C; Lyssiotis, Costas A; Cantley, Lewis C

    2016-01-01

    In the past decade, there has been a resurgence of interest in elucidating how metabolism is altered in cancer cells and how such dependencies can be targeted for therapeutic gain. At the core of this research is the concept that metabolic pathways are reprogrammed in cancer cells to divert nutrients toward anabolic processes to facilitate enhanced growth and proliferation. Importantly, physiological cellular signaling mechanisms normally tightly regulate the ability of cells to gain access to and utilize nutrients, posing a fundamental barrier to transformation. This barrier is often overcome by aberrations in cellular signaling that drive tumor pathogenesis by enabling cancer cells to make critical cellular decisions in a cell-autonomous manner. One of the most frequently altered pathways in human cancer is the PI3K-Akt-mTOR signaling pathway. Here, we describe mechanisms by which this signaling network is responsible for controlling cellular metabolism. Through both the post-translational regulation and the induction of transcriptional programs, the PI3K-Akt-mTOR pathway coordinates the uptake and utilization of multiple nutrients, including glucose, glutamine, nucleotides, and lipids, in a manner best suited for supporting the enhanced growth and proliferation of cancer cells. These regulatory mechanisms illustrate how metabolic changes in cancer are closely intertwined with oncogenic signaling pathways that drive tumor initiation and progression. PMID:27557534

  12. Computational Modeling of PI3K/AKT and MAPK Signaling Pathways in Melanoma Cancer

    PubMed Central

    Pappalardo, Francesco; Russo, Giulia; Candido, Saverio; Pennisi, Marzio; Cavalieri, Salvatore; Motta, Santo; McCubrey, James A.; Nicoletti, Ferdinando; Libra, Massimo

    2016-01-01

    Background Malignant melanoma is an aggressive tumor of the skin and seems to be resistant to current therapeutic approaches. Melanocytic transformation is thought to occur by sequential accumulation of genetic and molecular alterations able to activate the Ras/Raf/MEK/ERK (MAPK) and/or the PI3K/AKT (AKT) signalling pathways. Specifically, mutations of B-RAF activate MAPK pathway resulting in cell cycle progression and apoptosis prevention. According to these findings, MAPK and AKT pathways may represent promising therapeutic targets for an otherwise devastating disease. Result Here we show a computational model able to simulate the main biochemical and metabolic interactions in the PI3K/AKT and MAPK pathways potentially involved in melanoma development. Overall, this computational approach may accelerate the drug discovery process and encourages the identification of novel pathway activators with consequent development of novel antioncogenic compounds to overcome tumor cell resistance to conventional therapeutic agents. The source code of the various versions of the model are available as S1 Archive. PMID:27015094

  13. Suppression of Virulent Porcine Epidemic Diarrhea Virus Proliferation by the PI3K/Akt/GSK-3α/β Pathway.

    PubMed

    Kong, Ning; Wu, Yongguang; Meng, Qiong; Wang, Zhongze; Zuo, Yewen; Pan, Xi; Tong, Wu; Zheng, Hao; Li, Guoxin; Yang, Shen; Yu, Hai; Zhou, En-Min; Shan, Tongling; Tong, Guangzhi

    2016-01-01

    Porcine epidemic diarrhea virus (PEDV) has recently caused high mortality in suckling piglets with subsequent large economic losses to the swine industry. Many intracellular signaling pathways, including the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, are activated by viral infection. The PI3K/Akt pathway is an important cellular pathway that has been shown to be required for virus replication. In the present study, we found that the PEDV JS-2013 strain activated Akt in Vero cells at early (5-15 min) and late stages (8-10 h) of infection. Inhibiting PI3K, an upstream activator of Akt, enhanced PEDV replication. Inhibiting GSK-3α/β, one of the downstream effectors of PI3K/Akt pathway and regulated by Akt during PEDV infected Vero cells, also enhanced PEDV replication. Collectively, our data suggest that PI3K/Akt/GSK-3α/β signaling pathway is activated by PEDV and functions in inhibiting PEDV replication. PMID:27560518

  14. Suppression of Virulent Porcine Epidemic Diarrhea Virus Proliferation by the PI3K/Akt/GSK-3α/β Pathway

    PubMed Central

    Kong, Ning; Wu, Yongguang; Meng, Qiong; Wang, Zhongze; Zuo, Yewen; Pan, Xi; Tong, Wu; Zheng, Hao; Li, Guoxin; Yang, Shen; Yu, Hai; Zhou, En-min; Shan, Tongling; Tong, Guangzhi

    2016-01-01

    Porcine epidemic diarrhea virus (PEDV) has recently caused high mortality in suckling piglets with subsequent large economic losses to the swine industry. Many intracellular signaling pathways, including the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, are activated by viral infection. The PI3K/Akt pathway is an important cellular pathway that has been shown to be required for virus replication. In the present study, we found that the PEDV JS-2013 strain activated Akt in Vero cells at early (5–15 min) and late stages (8–10 h) of infection. Inhibiting PI3K, an upstream activator of Akt, enhanced PEDV replication. Inhibiting GSK-3α/β, one of the downstream effectors of PI3K/Akt pathway and regulated by Akt during PEDV infected Vero cells, also enhanced PEDV replication. Collectively, our data suggest that PI3K/Akt/GSK-3α/β signaling pathway is activated by PEDV and functions in inhibiting PEDV replication. PMID:27560518

  15. The role of the PI3K-Akt signal transduction pathway in Autographa californica multiple nucleopolyhedrovirus infection of Spodoptera frugiperda cells

    SciTech Connect

    Xiao Wei; Yang Yi; Weng Qingbei; Lin Tiehao; Yuan Meijin; Yang Kai; Pang Yi

    2009-08-15

    Many viruses activate the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway, thereby modulating diverse downstream signaling pathways associated with antiapoptosis, proliferation, cell cycling, protein synthesis and glucose metabolism, in order to augment their replication. To date, the role of the PI3K-Akt pathway in Baculovirus replication has not been defined. In the present study, we demonstrate that infection of Sf9 cells with Autographa californica multiple nucleopolyhedrovirus (AcMNPV) elevated cellular Akt phosphorylation at 1 h post-infection. The maximum Akt phosphorylation occurred at 6 h post-infection and remained unchanged until 18 h post-infection. The PI3K-specific inhibitor, LY294002, suppressed Akt phosphorylation in a dose-dependent manner, suggesting that AcMNPV-induced Akt phosphorylation is PI3K-dependent. The inhibition of PI3K-Akt activation by LY294002 significantly reduced the viral yield, including a reduction in budded viruses and occlusion bodies. The virus production was reduced only when the inhibitor was added within 24 h of infection, implying that activation of PI3K occurred early in infection. Correspondingly, both viral DNA replication and late (VP39) and very late (POLH) viral protein expression were impaired by LY294002 treatment; LY294002 had no effect on immediate-early (IE1) and early-late (GP64) protein expression. These results demonstrate that the PI3K-Akt pathway is required for efficient Baculovirus replication.

  16. The role of the PI3K/Akt/mTOR signalling pathway in human cancers induced by infection with human papillomaviruses.

    PubMed

    Zhang, Lifang; Wu, Jianhong; Ling, Ming Tat; Zhao, Liang; Zhao, Kong-Nan

    2015-01-01

    Infection with Human papillomaviruses (HPVs) leads to the development of a wide-range of cancers, accounting for 5% of all human cancers. A prominent example is cervical cancer, one of the leading causes of cancer death in women worldwide. It has been well established that tumor development and progression induced by HPV infection is driven by the sustained expression of two oncogenes E6 and E7. The expression of E6 and E7 not only inhibits the tumor suppressors p53 and Rb, but also alters additional signalling pathways that may be equally important for transformation. Among these pathways, the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signalling cascade plays a very important role in HPV-induced carcinogenesis by acting through multiple cellular and molecular events. In this review, we summarize the frequent amplification of PI3K/Akt/mTOR signals in HPV-induced cancers and discuss how HPV oncogenes E6/E7/E5 activate the PI3K/Akt/mTOR signalling pathway to modulate tumor initiation and progression and affect patient outcome. Improvement of our understanding of the mechanism by which the PI3K/Akt/mTOR signalling pathway contributes to the immortalization and carcinogenesis of HPV-transduced cells will assist in devising novel strategies for preventing and treating HPV-induced cancers. PMID:26022660

  17. The role of the PI3K/Akt/mTOR signalling pathway in human cancers induced by infection with human papillomaviruses.

    PubMed

    Zhang, Lifang; Wu, Jianhong; Ling, Ming Tat; Zhao, Liang; Zhao, Kong-Nan

    2015-04-17

    Infection with Human papillomaviruses (HPVs) leads to the development of a wide-range of cancers, accounting for 5% of all human cancers. A prominent example is cervical cancer, one of the leading causes of cancer death in women worldwide. It has been well established that tumor development and progression induced by HPV infection is driven by the sustained expression of two oncogenes E6 and E7. The expression of E6 and E7 not only inhibits the tumor suppressors p53 and Rb, but also alters additional signalling pathways that may be equally important for transformation. Among these pathways, the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signalling cascade plays a very important role in HPV-induced carcinogenesis by acting through multiple cellular and molecular events. In this review, we summarize the frequent amplification of PI3K/Akt/mTOR signals in HPV-induced cancers and discuss how HPV oncogenes E6/E7/E5 activate the PI3K/Akt/mTOR signalling pathway to modulate tumor initiation and progression and affect patient outcome. Improvement of our understanding of the mechanism by which the PI3K/Akt/mTOR signalling pathway contributes to the immortalization and carcinogenesis of HPV-transduced cells will assist in devising novel strategies for preventing and treating HPV-induced cancers.

  18. Icaritin requires Phosphatidylinositol 3 kinase (PI3K)/Akt signaling to counteract skeletal muscle atrophy following mechanical unloading

    PubMed Central

    ZHANG, Zong-Kang; LI, Jie; LIU, Jin; GUO, Baosheng; LEUNG, Albert; ZHANG, Ge; ZHANG, Bao-Ting

    2016-01-01

    Counteracting muscle atrophy induced by mechanical unloading/inactivity is of great clinical need and challenge. A therapeutic agent that could counteract muscle atrophy following mechanical unloading in safety is desired. This study showed that natural product Icaritin (ICT) could increase the phosphorylation level of Phosphatidylinositol 3 kinase (PI3K) at p110 catalytic subunit and promote PI3K/Akt signaling markers in C2C12 cells. This study further showed that the high dose ICT treatment could significantly attenuate the decreases in the phosphorylation level of PI3K at p110 catalytic subunit and its downstream markers related to protein synthesis, and inhibit the increases in protein degradation markers at mRNA and protein levels in rat soleus muscle following 28-day hindlimb unloading. In addition, the decreases in soleus muscle mass, muscle fiber cross-sectional area, twitch force, specific force, contraction time and half relaxation time could be significantly attenuated by the high dose ICT treatment. The low dose ICT treatment could moderately attenuate the above changes induced by unloading. Wortmannin, a specific inhibitor of PI3K at p110 catalytic subunit, could abolish the above effects of ICT in vitro and in vivo, indicating that PI3K/Akt signaling could be required by ICT to counteract skeletal muscle atrophy following mechanical unloading. PMID:26831566

  19. α-2,8-Sialyltransferase Is Involved in the Development of Multidrug Resistance via PI3K/Akt Pathway in Human Chronic Myeloid Leukemia.

    PubMed

    Zhang, Xu; Dong, Weijie; Zhou, Huimin; Li, Hongshuai; Wang, Ning; Miao, Xiaoyan; Jia, Li

    2015-02-01

    Cell surface sialylation is emerging as an important feature of cancer cell multidrug resistance (MDR). We have focused on the influence of 2,8-sialyltransferases in key steps of the development of MDR in chronic myeloid leukemia (CML). The expressional profiles of six α-2,8-sialyltransferases were generated in three pairs of CML cell lines and peripheral blood mononuclear cells (PBMC) of CML patients. Cellular MDR phenotype positively correlated with ST8SIA4 and ST8SIA6 levels. Furthermore, ST8SIA4 mediated the activity of phosphoinositide-3 kinase (PI3K)/Akt signal pathway and the expression of P-glycoprotein (P-gp). Targeting the PI3K/Akt pathway by its specific inhibitor LY294002, or by Akt RNA interfering reversed the MDR phenotype of K562/ADR cells. Inhibition of PI3K/Akt pathway also attenuated the effects caused by the overexpression of ST8SIA4 on MDR. Therefore this study indicated that α-2,8-sialyltransferases involved in the development of MDR of CML cells probably through ST8SIA4 regulating the activity of PI3K/Akt signaling and the expression of P-gp. PMID:25855199

  20. Activation of PI3K/Akt pathway limits JNK-mediated apoptosis during EV71 infection.

    PubMed

    Zhang, Hua; Li, Fengqi; Pan, Ziye; Wu, Zhijun; Wang, Yanhong; Cui, Yudong

    2014-11-01

    Apoptosis is frequently induced to inhibit virus replication during infection of Enterovirus 71 (EV71). On the contrary, anti-apoptotic pathway, such as PI3K/Akt pathway, is simultaneously exploited by EV71 to accomplish the viral life cycle. The relationship by which EV71-induced apoptosis and PI3K/Akt signaling pathway remains to be elucidated. In this study, we demonstrated that EV71 infection altered Bax conformation and triggered its redistribution from the cytosol to mitochondria in RD cells. Subsequently, cytochrome c was released from mitochondria to cytosol. We also found that c-Jun NH2-terminal kinase (JNK) was activated during EV71 infection. The JNK specific inhibitor significantly inhibited Bax activation and cytochrome c release, suggesting that EV71-induced apoptosis was involved into a JNK-dependent manner. Meanwhile, EV71-induced Akt phosphorylation involved a PI3K-dependent mechanism. Inhibition of the PI3K/Akt pathway enhanced JNK phosphorylation and the JNK-mediated apoptosis upon EV71 infection. Moreover, PI3K/Akt pathway phosphorylated apoptosis signal-regulating kinase 1 (ASK1) and negatively regulated the ASK1 activity. Knockdown of ASK1 significantly decreased JNK phosphorylation, which implied that ASK1 phosphorylation by Akt inhibited ASK1-mediated JNK activation. Collectively, these data reveal that activation of the PI3K/Akt pathway limits JNK-mediated apoptosis by phosphorylating and inactivating ASK1 during EV71 infection.

  1. PI3K/Akt is involved in brown adipogenesis mediated by growth differentiation factor-5 in association with activation of the Smad pathway

    SciTech Connect

    Hinoi, Eiichi; Iezaki, Takashi; Fujita, Hiroyuki; Watanabe, Takumi; Odaka, Yoshiaki; Ozaki, Kakeru; Yoneda, Yukio

    2014-07-18

    Highlights: • Akt is preferentially phosphorylated in BAT and sWAT of aP2-GDF5 mice. • PI3K/Akt signaling is involved in GDF5-induced brown adipogenesis. • PI3K/Akt signaling regulates GDF5-induced Smad5 phosphorylation. - Abstract: We have previously demonstrated promotion by growth differentiation factor-5 (GDF5) of brown adipogenesis for systemic energy expenditure through a mechanism relevant to activating the bone morphological protein (BMP) receptor/mothers against decapentaplegic homolog (Smad)/peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) pathway. Here, we show the involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in brown adipogenesis mediated by GDF5. Overexpression of GDF5 in cells expressing adipocyte protein-2 markedly accelerated the phosphorylation of Smad1/5/8 and Akt in white and brown adipose tissues. In brown adipose tissue from heterozygous GDF5{sup Rgsc451} mutant mice expressing a dominant-negative (DN) GDF5 under obesogenic conditions, the basal phosphorylation of Smad1/5/8 and Akt was significantly attenuated. Exposure to GDF5 not only promoted the phosphorylation of both Smad1/5/8 and Akt in cultured brown pre-adipocytes, but also up-regulated Pgc1a and uncoupling protein-1 expression in a manner sensitive to the PI3K/Akt inhibitor Ly294002 as well as retroviral infection with DN-Akt. GDF5 drastically promoted BMP-responsive luciferase reporter activity in a Ly294002-sensitive fashion. Both Ly294002 and DN-Akt markedly inhibited phosphorylation of Smad5 in the nuclei of brown pre-adipocytes. These results suggest that PI3K/Akt signals play a role in the GDF5-mediated brown adipogenesis through a mechanism related to activation of the Smad pathway.

  2. Cell type-specific dependency on the PI3K/Akt signaling pathway for the endogenous Epo and VEGF induction by baicalein in neurons versus astrocytes.

    PubMed

    Sun, Yu-Yo; Lin, Shang-Hsuan; Lin, Hung-Cheng; Hung, Chia-Chi; Wang, Chen-Yu; Lin, Yen-Chu; Hung, Kuo-Sheng; Lien, Cheng-Chang; Kuan, Chia-Yi; Lee, Yi-Hsuan

    2013-01-01

    The neuroprotective effect of baicalein is generally attributed to inhibition of 12/15-lipoxygenase (12/15-LOX) and suppression of oxidative stress, but recent studies showed that baicalein also activates hypoxia-inducible factor-α (HIF1α) through inhibition of prolyl hydrolase 2 (PHD2) and activation of the phosphatidylinositide-3 kinase (PI3K)/Akt signaling pathway. Yet, the significance and regulation of prosurvival cytokines erythropoietin (Epo) and vascular endothelial growth factor (VEGF), two transcriptional targets of HIF1α, in baicalein-mediated neuroprotection in neurons and astrocytes remains unknown. Here we investigated the causal relationship between the PI3K/Akt signaling pathway and Epo/VEGF expression in baicalein-mediated neuroprotection in primary rat cortical neurons and astrocytes. Our results show that baicalein induced Epo and VEGF expression in a HIF1α- and PI3K/Akt-dependent manner in neurons. Baicalein also protected neurons against excitotoxicity in a PI3K- and Epo/VEGF-dependent manner without affecting neuronal excitability. In contrast, at least a 10-fold higher concentration of baicalein was needed to induce Epo/VEGF production and PI3K/Akt activity in astrocytes for protection of neurons. Moreover, only baicalein-induced astrocytic VEGF, but not Epo expression requires HIF1α, while PI3K/Akt signaling had little role in baicalein-induced astrocytic Epo/VEGF expression. These results suggest distinct mechanisms of baicalein-mediated Epo/VEGF production in neurons and astrocytes for neuroprotection, and provide new insights into the mechanisms and potential of baicalein in treating brain injury in vivo. PMID:23904909

  3. Dual targeting of the PI3K/Akt/mTOR pathway as an antitumor strategy in Waldenstrom macroglobulinemia

    PubMed Central

    Roccaro, Aldo M.; Sacco, Antonio; Husu, Emanuel N.; Pitsillides, Costas; Vesole, Steven; Azab, Abdel Kareem; Azab, Feda; Melhem, Molly; Ngo, Hai T.; Quang, Phong; Maiso, Patricia; Runnels, Judith; Liang, Mei-Chih; Wong, Kwok-Kin; Lin, Charles

    2010-01-01

    We have previously shown clinical activity of a mammalian target of rapamycin (mTOR) complex 1 inhibitor in Waldenstrom macroglobulinemia (WM). However, 50% of patients did not respond to therapy. We therefore examined mechanisms of activation of the phosphoinositide 3-kinase (PI3K)/Akt/mTOR in WM, and mechanisms of overcoming resistance to therapy. We first demonstrated that primary WM cells show constitutive activation of the PI3K/Akt pathway, supported by decreased expression of phosphate and tensin homolog tumor suppressor gene (PTEN) at the gene and protein levels, together with constitutive activation of Akt and mTOR. We illustrated that dual targeting of the PI3K/mTOR pathway by the novel inhibitor NVP-BEZ235 showed higher cytotoxicity on WM cells compared with inhibition of the PI3K or mTOR pathways alone. In addition, NVP-BEZ235 inhibited both rictor and raptor, thus abrogating the rictor-induced Akt phosphorylation. NVP-BEZ235 also induced significant cytotoxicity in WM cells in a caspase-dependent and -independent manner, through targeting the Forkhead box transcription factors. In addition, NVP-BEZ235 targeted WM cells in the context of bone marrow microenvironment, leading to significant inhibition of migration, adhesion in vitro, and homing in vivo. These studies therefore show that dual targeting of the PI3K/mTOR pathway is a better modality of targeted therapy for tumors that harbor activation of the PI3K/mTOR signaling cascade, such as WM. PMID:19965685

  4. Cabazitaxel-induced autophagy via the PI3K/Akt/mTOR pathway contributes to A549 cell death

    PubMed Central

    Huo, Ruichao; Wang, Lili; Liu, Peijuan; Zhao, Yong; Zhang, Caiqin; Bai, Bing; Liu, Xueying; Shi, Changhong; Wei, Sanhua; Zhang, Hai

    2016-01-01

    Cabazitaxel has been used to treat castration-resistant prostate cancer since its approval by the US Food and Drug Administration in 2010. However, whether cabazitaxel may inhibit the proliferation of other tissue-derived cancer cells, and its underlying mechanism, remains unknown. In the present study, the A549 lung adenocarcinoma cancer cell line was exposed to cabazitaxel, in order to investigate its cytotoxic effect and determine the underlying mechanism. The results demonstrated that cabazitaxel was able to induce autophagy in A549 cells, as evidenced by the formation of autophagosomes, upregulated LC3-II expression and increased LC3 puncta. Cabazitaxel-induced autophagy had a cytotoxic effect on A549 cells, as evidenced by the induction of cell death and cell cycle arrest at G2/M phase, which was independent of the apoptotic pathway. Furthermore, transfection with Beclin1 small interfering RNA and treatment with the autophagy inhibitor 3-methyladenine protected cells from cabazitaxel-induced cell death, thus confirming that cabazitaxel-induced autophagy contributed to A549 cell death. In addition, cabazitaxel targeted the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway to induce autophagy, as indicated by reduced phosphorylation of Akt and mTOR. In conclusion, the present study demonstrated that cabazitaxel exerts a cytotoxic effect on A549 cells by acting on the PI3K/Akt/mTOR pathway to promote autophagic cell death. This result supports the potential use of cabazitaxel as a chemotherapeutic agent for the treatment of lung cancer. PMID:27572899

  5. Anger Emotional Stress Influences VEGF/VEGFR2 and Its Induced PI3K/AKT/mTOR Signaling Pathway

    PubMed Central

    Sun, Peng; Wei, Sheng; Wei, Xia; Wang, Jieqiong; Zhang, Yuanyuan; Qiao, Mingqi; Wu, Jibiao

    2016-01-01

    Objective. We discuss the influence of anger emotional stress upon VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway. Methods. We created a rat model of induced anger (anger-out and anger-in) emotional response using social isolation and resident-intruder paradigms and assessed changes in hippocampus' VEGF content, neuroplasticity, and the PI3K/AKT/mTOR signaling pathway. Results. The resident-intruder method successfully generated anger-out and anger-in models that differed significantly in composite aggression score, aggression incubation, open field behavior, sucrose preference, and weight gain. Anger emotional stress decreased synaptic connections and VEGFR2 expression. Anger emotional stress led to abnormal expression of VEGF/VEGFR2 mRNA and protein and disorderly expression of key factors in the PI3K/AKT/mTOR signal pathway. Fluoxetine administration ameliorated behavioral abnormalities and damage to hippocampal neurons caused by anger emotional stress, as well as abnormal expression of some proteins in VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway. Conclusion. This research provides a detailed classification of anger emotion and verifies its influence upon VEGF and the VEGF-induced signaling pathway, thus providing circumstantial evidence of mechanisms by which anger emotion damages neurogenesis. As VEGFR2 can promote neurogenesis and vasculogenesis in the hippocampus and frontal lobe, these results suggest that anger emotional stress can result in decreased neurogenesis. PMID:27057362

  6. Anger Emotional Stress Influences VEGF/VEGFR2 and Its Induced PI3K/AKT/mTOR Signaling Pathway.

    PubMed

    Sun, Peng; Wei, Sheng; Wei, Xia; Wang, Jieqiong; Zhang, Yuanyuan; Qiao, Mingqi; Wu, Jibiao

    2016-01-01

    Objective. We discuss the influence of anger emotional stress upon VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway. Methods. We created a rat model of induced anger (anger-out and anger-in) emotional response using social isolation and resident-intruder paradigms and assessed changes in hippocampus' VEGF content, neuroplasticity, and the PI3K/AKT/mTOR signaling pathway. Results. The resident-intruder method successfully generated anger-out and anger-in models that differed significantly in composite aggression score, aggression incubation, open field behavior, sucrose preference, and weight gain. Anger emotional stress decreased synaptic connections and VEGFR2 expression. Anger emotional stress led to abnormal expression of VEGF/VEGFR2 mRNA and protein and disorderly expression of key factors in the PI3K/AKT/mTOR signal pathway. Fluoxetine administration ameliorated behavioral abnormalities and damage to hippocampal neurons caused by anger emotional stress, as well as abnormal expression of some proteins in VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway. Conclusion. This research provides a detailed classification of anger emotion and verifies its influence upon VEGF and the VEGF-induced signaling pathway, thus providing circumstantial evidence of mechanisms by which anger emotion damages neurogenesis. As VEGFR2 can promote neurogenesis and vasculogenesis in the hippocampus and frontal lobe, these results suggest that anger emotional stress can result in decreased neurogenesis. PMID:27057362

  7. RES-529: a PI3K/AKT/mTOR pathway inhibitor that dissociates the mTORC1 and mTORC2 complexes

    PubMed Central

    2016-01-01

    RES-529 (previously named Palomid 529, P529) is a phosphoinositide 3-kinase (PI3K)/AKT/mechanistic target of rapamycin (mTOR) pathway inhibitor that interferes with the pathway through both mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) dissociation. This compound is currently being developed in oncology and ophthalmology. The oncology focus is for the treatment of glioblastoma, where it has received orphan designation by the US Food and Drug Administration, and prostate cancer. We present a review of the PI3K/AKT/mTOR pathway, its role in tumorigenesis, and the potential of RES-529 in cancer treatment. RES-529 inhibits mTORC1/mTORC2 activity in various cancer cell lines, as noted by decreased phosphorylation of substrates including ribosomal protein S6, 4E-BP1, and AKT, leading to cell growth inhibition and death, with activity generally in the range of 5–15 μmol/l. In animal tumor models where the PI3K/AKT/mTOR pathway is abnormally activated (i.e. glioblastoma, prostate cancer, and breast cancer), RES-529 reduces tumor growth by as much as 78%. RES-529 treatment is synergistic with radiation therapy, chemotherapy, and hormonal therapy in reducing tumor growth, potentially by preventing PI3K/AKT/mTOR pathway activation associated with these treatments. Furthermore, this compound has shown antiangiogenic activity in several animal models. mTORC1 and mTORC2 have redundant and distinct activities that contribute toward oncogenesis. Current inhibitors of this pathway have primarily targeted mTORC1, but have shown limited clinical efficacy. Inhibitors of mTORC1 and mTORC2 such as RES-529 may therefore have the potential to overcome the deficiencies found in targeting only mTORC1. PMID:26918392

  8. Quercetin suppresses HeLa cells by blocking PI3K/Akt pathway.

    PubMed

    Xiang, Tao; Fang, Yong; Wang, Shi-Xuan

    2014-10-01

    To explore the effect of quercetin on the proliferation and apoptosis of HeLa cells, HeLa cells were incubated with quercetin at different concentrations. Cell viability was evaluated by MTT assay, cell apoptosis was detected by Annexin-V/PI double labeled cytometry and DNA ladder assay. Cell cycle was flow cytometrically determined and the morphological changes of the cells were observed under a fluorescence microscope after Hoechst 33258 staining and the apoptosis-related proteins in the HeLa cells were assessed by Western blotting. The results showed that quercetin significantly inhibited the growth of HeLa cells and induced obvious apoptosis in vitro in a time- and dose-dependent manner. Moreover, quercetin induced apoptosis of HeLa cells in cell cycle-dependent manner because quercetin could induce arrest of HeLa cells at G0/G1 phase. Quercetin treatment down-regulated the expression of the PI3K and p-Akt. In addition, quercetin could down-regulate expression of bcl-2, up-regulate Bax, but exerted no effect on the overall expression of Akt. We are led to conclude that quercetin induces apoptosis via PI3k/Akt pathways, and quercetin has potential to be used as an anti-tumor agent against human cervix cancer.

  9. Novel agents and associated toxicities of inhibitors of the pi3k/Akt/mtor pathway for the treatment of breast cancer

    PubMed Central

    Chia, S.; Gandhi, S.; Joy, A.A.; Edwards, S.; Gorr, M.; Hopkins, S.; Kondejewski, J.; Ayoub, J.P.; Califaretti, N.; Rayson, D.; Dent, S.F.

    2015-01-01

    The pi3k/Akt/mtor (phosphatidylinositol 3 kinase/ Akt/mammalian target of rapamycin) signalling pathway is an established driver of oncogenic activity in human malignancies. Therapeutic targeting of this pathway holds significant promise as a treatment strategy. Everolimus, an mtor inhibitor, is the first of this class of agents approved for the treatment of hormone receptor–positive, human epidermal growth factor receptor 2–negative advanced breast cancer. Everolimus has been associated with significant improvements in progression-free survival; however, it is also associated with increased toxicity related to its specific mechanism of action. Methods A comprehensive review of the literature conducted using a focused medline search was combined with a search of current trials at http://ClinicalTrials.gov/. Summary tables of the toxicities of the various classes of pi3k/Akt/mtor inhibitors were created. A broad group of Canadian health care professionals was assembled to review the data and to produce expert opinion and summary recommendations for possible best practices in managing the adverse events associated with these pathway inhibitors. Results Differing toxicities are associated with the various classes of pi3k/Akt/mtor pathway inhibitors. The most common unique adverse events observed in everolimus clinical trials in breast cancer include stomatitis (all grades: approximately 60%), noninfectious pneumonitis (15%), rash (40%), hyperglycemia (15%), and immunosuppression (40%). To minimize grades 3 and 4 toxicities and to attempt to attain optimal outcomes, effective management of those adverse events is critical. Management should be interdisciplinary and should use approaches that include education, early recognition, active intervention, and potentially prophylactic strategies. Discussion Everolimus likely represents the first of many complex oral targeted therapies for the treatment of breast cancer. Using this agent as a template, it is essential to

  10. Chloroquine or Chloroquine-PI3K/Akt Pathway Inhibitor Combinations Strongly Promote γ-Irradiation-Induced Cell Death in Primary Stem-Like Glioma Cells

    PubMed Central

    Firat, Elke; Weyerbrock, Astrid; Gaedicke, Simone; Grosu, Anca-Ligia; Niedermann, Gabriele

    2012-01-01

    We asked whether inhibitors of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, which is highly active in cancer stem cells (CSCs) and upregulated in response to genotoxic treatments, promote γ-irradiationγIR)-induced cell death in highly radioresistant, patient-derived stem-like glioma cells (SLGCs). Surprisingly, in most cases the inhibitors did not promote γIR-induced cell death. In contrast, the strongly cytostatic Ly294002 and PI-103 even tended to reduce it. Since autophagy was induced we examined whether addition of the clinically applicable autophagy inhibitor chloroquine (CQ) would trigger cell death in SLGCs. Triple therapy with CQ at doses as low as 5 to 10 µM indeed caused strong apoptosis. At slightly higher doses, CQ alone strongly promoted γIR-induced apoptosis in all SLGC lines examined. The strong apoptosis in combinations with CQ was invariably associated with strong accumulation of the autophagosomal marker LC3-II, indicating inhibition of late autophagy. Thus, autophagy-promoting effects of PI3K/Akt pathway inhibitors apparently hinder cell death induction in γ-irradiated SLGCs. However, as we show here for the first time, the late autophagy inhibitor CQ strongly promotes γIR-induced cell death in highly radioresistant CSCs, and triple combinations of CQ, γIR and a PI3K/Akt pathway inhibitor permit reduction of the CQ dose required to trigger cell death. PMID:23091617

  11. MiR-20a Induces Cell Radioresistance by Activating the PTEN/PI3K/Akt Signaling Pathway in Hepatocellular Carcinoma

    SciTech Connect

    Zhang, Yuqin; Zheng, Lin; Ding, Yi; Li, Qi; Wang, Rong; Liu, Tongxin; Sun, Quanquan; Yang, Hua; Peng, Shunli; Wang, Wei; Chen, Longhua

    2015-08-01

    Purpose: To investigate the role of miR-20a in hepatocellular carcinoma (HCC) cell radioresistance, which may reveal potential strategies to improve treatment. Methods and Materials: The expression of miR-20a and PTEN were detected in HCC cell lines and paired primary tissues by quantitative real-time polymerase chain reaction. Cell radiation combined with colony formation assays was administrated to discover the effect of miR-20a on radiosensitivity. Bioinformatics prediction and luciferase assay were used to identify the target of miR-20a. The phosphatidylinositol 3-kinase inhibitor LY294002 was used to inhibit phosphorylation of Akt, to verify whether miR-20a affects HCC cell radioresistance through activating the PTEN/PI3K/Akt pathway. Results: MiR-20a levels were increased in HCC cell lines and tissues, whereas PTEN was inversely correlated with it. Overexpression of miR-20a in Bel-7402 and SMMC-7721 cells enhances their resistance to the effect of ionizing radiation, and the inhibition of miR-20a in HCCLM3 and QGY-7701 cells sensitizes them to it. PTEN was identified as a direct functional target of miR-20a for the induction of radioresistance. Overexpression of miR-20a activated the PTEN/PI3K/Akt signaling pathway. Additionally, the kinase inhibitor LY294002 could reverse the effect of miR-20a–induced radioresistance. Conclusion: MiR-20a induces HCC cell radioresistance by activating the PTEN/PI3K/Akt pathway, which suggests that miR-20a/PTEN/PI3K/Akt might represent a target of investigation for developing effective therapeutic strategies against HCC.

  12. Metastatic function of BMP-2 in gastric cancer cells: The role of PI3K/AKT, MAPK, the NF-{kappa}B pathway, and MMP-9 expression

    SciTech Connect

    Kang, Myoung Hee; Oh, Sang Cheul; Kang, Han Na; Kim, Jung Lim; Kim, Jun Suk

    2011-07-15

    Bone morphogenetic proteins (BMPs) have been implicated in tumorigenesis and metastatic progression in various types of cancer cells, but the role and cellular mechanism in the invasive phenotype of gastric cancer cells is not known. Herein, we determined the roles of phosphoinositide 3-kinase (PI3K)/AKT, extracellular signal-regulated protein kinase (ERK), nuclear factor (NF)-{kappa}B, and matrix metalloproteinase (MMP) expression in BMP-2-mediated metastatic function in gastric cancer. We found that stimulation of BMP-2 in gastric cancer cells enhanced the phosphorylation of AKT and ERK. Accompanying activation of AKT and ERK kinase, BMP-2 also enhanced phosphorylation/degradation of I{kappa}B{alpha} and the nuclear translocation/activation of NF-{kappa}B. Interestingly, blockade of PI3K/AKT and ERK signaling using LY294002 and PD98059, respectively, significantly inhibited BMP-2-induced motility and invasiveness in association with the activation of NF-{kappa}B. Furthermore, BMP-2-induced MMP-9 expression and enzymatic activity was also significantly blocked by treatment with PI3K/AKT, ERK, or NF-{kappa}B inhibitors. Immunohistochemistry staining of 178 gastric tumor biopsies indicated that expression of BMP-2 and MMP-9 had a significant positive correlation with lymph node metastasis and a poor prognosis. These results indicate that the BMP-2 signaling pathway enhances tumor metastasis in gastric cancer by sequential activation of the PI3K/AKT or MAPK pathway followed by the induction of NF-{kappa}B and MMP-9 activity, indicating that BMP-2 has the potential to be a therapeutic molecular target to decrease metastasis.

  13. Upregulated WDR26 serves as a scaffold to coordinate PI3K/ AKT pathway-driven breast cancer cell growth, migration, and invasion.

    PubMed

    Ye, Yuanchao; Tang, Xiaoyun; Sun, Zhizeng; Chen, Songhai

    2016-04-01

    The phosphatidylinositol 3-kinase (PI3K)/AKT pathway transmits signals downstream of receptor tyrosine kinases and G protein-coupled receptors (GPCRs), and is one of the most dysregulated pathways in breast cancer. PI3Ks and AKTs consist of multiple isoforms that play distinct and even opposite roles in breast cancer cell growth and metastasis. However, it remains unknown how the activities of various PI3K and AKT isoforms are coordinated during breast cancer progression. Previously, we showed WDR26 is a novel WD40 protein that binds Gβγ and promotes Gβγ signaling. Here, we demonstrate that WDR26 is overexpressed in highly malignant breast tumor cell lines and human breast cancer samples, and that WDR26 overexpression correlates with shortened survival of breast cancer patients. In highly malignant cell lines (MDA-MB231, DU4475 and BT549), downregulation of WDR26 expression selectively alleviated GPCR- but not EGF receptor-stimulated PI3K/AKT signaling and tumor cell growth, migration and invasion. In contrast, in a less malignant cell line (MCF7), WDR26 overexpression had the opposite effect. Additional studies indicate that downstream of GPCR stimulation, WDR26 serves as a scaffold that fosters assembly of a specific signaling complex consisting of Gβγ, PI3Kβ and AKT2. In an orthotopic xenograft mouse model of breast cancer, disrupting formation of this complex, by overexpressing WDR26 mutants in MDA-MB231 cells, abrogated PI3K/AKT activation and tumor cell growth and metastasis. Together, our results identify a novel mechanism regulating GPCR-dependent activation of the PI3K/AKT signaling axis in breast tumor cells, and pinpoint WDR26 as a potential therapeutic target for breast cancer.

  14. Dietary regulation of PI3K/AKT/GSK-3β pathway in Alzheimer’s disease

    PubMed Central

    2014-01-01

    Alzheimer’s disease (AD) is characterized by the formation of senile plaques and neurofibrillary tangles composed of phosphorylated Tau. Several findings suggest that correcting signal dysregulation for Tau phosphorylation in AD may offer a potential therapeutic approach. The PI3K/AKT/GSK-3β pathway has been shown to play a pivotal role in neuroprotection, enhancing cell survival by stimulating cell proliferation and inhibiting apoptosis. This pathway appears to be crucial in AD because it promotes protein hyper-phosphorylation in Tau. Understanding those regulations may provide a better efficacy of new therapeutic approaches. In this review, we summarize advances in the involvement of the PI3K/AKT/GSK-3β pathways in cell signaling of neuronal cells. We also review recent studies on the features of several diets and the signaling pathway involved in AD. PMID:25031641

  15. Computer-Aided Targeting of the PI3K/Akt/mTOR Pathway: Toxicity Reduction and Therapeutic Opportunities

    PubMed Central

    Li, Tan; Wang, Guanyu

    2014-01-01

    The PI3K/Akt/mTOR pathway plays an essential role in a wide range of biological functions, including metabolism, macromolecular synthesis, cell growth, proliferation and survival. Its versatility, however, makes it a conspicuous target of many pathogens; and the consequential deregulations of this pathway often lead to complications, such as tumorigenesis, type 2 diabetes and cardiovascular diseases. Molecular targeted therapy, aimed at modulating the deregulated pathway, holds great promise for controlling these diseases, though side effects may be inevitable, given the ubiquity of the pathway in cell functions. Here, we review a variety of factors found to modulate the PI3K/Akt/mTOR pathway, including gene mutations, certain metabolites, inflammatory factors, chemical toxicants, drugs found to rectify the pathway, as well as viruses that hijack the pathway for their own synthetic purposes. Furthermore, this evidence of PI3K/Akt/mTOR pathway alteration and related pathogenesis has inspired the exploration of computer-aided targeting of this pathway to optimize therapeutic strategies. Herein, we discuss several possible options, using computer-aided targeting, to reduce the toxicity of molecularly-targeted therapy, including mathematical modeling, to reveal system-level control mechanisms and to confer a low-dosage combination therapy, the potential of PP2A as a therapeutic target, the formulation of parameters to identify patients who would most benefit from specific targeted therapies and molecular dynamics simulations and docking studies to discover drugs that are isoform specific or mutation selective so as to avoid undesired broad inhibitions. We hope this review will stimulate novel ideas for pharmaceutical discovery and deepen our understanding of curability and toxicity by targeting the PI3K/Akt/mTOR pathway. PMID:25334061

  16. Crosstalk Between MAPK/ERK and PI3K/AKT Signal Pathways During Brain Ischemia/Reperfusion

    PubMed Central

    Zhou, Jing; Du, Ting; Li, Baoman; Rong, Yan; Verkhratsky, Alexei

    2015-01-01

    The epidermal growth factor receptor (EGFR) is linked to the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and Raf/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK1/2) signaling pathways. During brain ischemia/reperfusion, EGFR could be transactivated, which stimulates these intracellular signaling cascades that either protect cells or potentiate cell injury. In the present study, we investigated the activation of EGFR, PI3K/AKT, and Raf/MAPK/ERK1/2 during ischemia or reperfusion of the brain using the middle cerebral artery occlusion model. We found that EGFR was phosphorylated and transactivated during both ischemia and reperfusion periods. During ischemia, the activity of PI3K/AKT pathway was significantly increased, as judged from the strong phosphorylation of AKT; this activation was suppressed by the inhibitors of EGFR and Zn-dependent metalloproteinase. Ischemia, however, did not induce ERK1/2 phosphorylation, which was dependent on reperfusion. Coimmunoprecipitation of Son of sevenless 1 (SOS1) with EGFR showed increased association between the receptor and SOS1 in ischemia, indicating the inhibitory node downstream of SOS1. The inhibitory phosphorylation site of Raf-1 at Ser259, but not its stimulatory phosphorylation site at Ser338, was phosphorylated during ischemia. Furthermore, ischemia prompted the interaction between Raf-1 and AKT, while both the inhibitors of PI3K and AKT not only abolished AKT phosphorylation but also restored ERK1/2 phosphorylation. All these findings suggest that Raf/MAPK/ERK1/2 signal pathway is inhibited by AKT via direct phosphorylation and inhibition at Raf-1 node during ischemia. During reperfusion, we observed a significant increase of ERK1/2 phosphorylation but no change in AKT phosphorylation. Inhibitors of reactive oxygen species and phosphatase and tensin homolog restored AKT phosphorylation but abolished ERK1/2 phosphorylation, suggesting that the reactive oxygen species

  17. Molecular Genetics of the PI3K-AKT-mTOR Pathway in Genodermatoses: Diagnostic Implications and Treatment Opportunities.

    PubMed

    Vahidnezhad, Hassan; Yousse An, Leila; Uitto, Jouni

    2016-01-01

    A number of critical signaling pathways are required for homeostatic regulation of cell survival, differentiation, and proliferation during organogenesis. One of them is the PI3K-AKT-mTOR pathway consisting of a cascade of inhibitor/activator molecules. Recently, a number of heritable diseases with skin involvement, manifesting particularly with tissue overgrowth, have been shown to result from mutations in the genes in the PI3K-AKT-mTOR and interacting intracellular pathways. Many of these conditions represent an overlapping spectrum of phenotypic manifestations forming a basis for novel, unifying classifications. Identification of the mutant genes and specific mutations in these patients has implications for diagnostics and genetic counseling and provides a rational basis for the development of novel treatment modalities for this currently intractable group of disorders.

  18. Insulin and IGFs enhance hepatocyte differentiation from human embryonic stem cells via the PI3K/AKT pathway.

    PubMed

    Magner, Nataly L; Jung, Yunjoon; Wu, Jian; Nolta, Jan A; Zern, Mark A; Zhou, Ping

    2013-10-01

    Human embryonic stem cells (hESCs) can be progressively differentiated into definitive endoderm (DE), hepatic progenitors, and hepatocytes, and thus provide an excellent model system for the mechanistic study of hepatocyte differentiation, which is currently poorly understood. Here, we found that insulin enhanced hepatocyte differentiation from hESC-derived DE. Insulin activated the PI3K/AKT pathway, but not the mitogen-activated protein kinase pathway in the DE cells, and inhibition of the PI3K/AKT pathways by inhibitors markedly inhibited hepatocyte differentiation. In addition, insulin-like growth factor 1 (IGF1) and IGF2 also activated the PI3K/AKT pathway in DE cells and their expression was robustly upregulated during hepatocyte differentiation from DE. Furthermore, inhibition of IGF receptor 1 (IGF1R) by a small molecule inhibitor PPP or knockdown of the IGF1R by shRNA attenuated hepatocyte differentiation. Moreover, simultaneous knockdown of the IGF1R and the insulin receptor with shRNAs markedly reduced the activation of AKT and substantially impaired hepatocyte differentiation. The PI3K pathway specifically enhanced the expression of HNF1 and HNF4 to regulate hepatocyte differentiation from DE. Although inhibition of the PI3K pathway was previously shown to be required for the induction of DE from hESCs, our study revealed a positive role of the PI3K pathway in hepatocyte differentiation after the DE stage, and has advanced our understanding of hepatocyte cell fate determination.

  19. Asiaticoside attenuates diabetes-induced cognition deficits by regulating PI3K/Akt/NF-κB pathway.

    PubMed

    Yin, Zhujun; Yu, Haiyang; Chen, She; Ma, Chunhua; Ma, Xiao; Xu, Lixing; Ma, Zhanqiang; Qu, Rong; Ma, Shiping

    2015-10-01

    Diabetes-associated cognitive dysfunction, referred as "diabetic encephalopathy", has been confirmed in a great deal of literature. Current evidence support that oxidative stress, inflammation, energy metabolism imbalance, and aberrant insulin signaling are associated with cognition deficits induced by diabetes. The present study explore the effect of asiaticoside on the cognition behaviors, synapses, and oxidative stress in diabetic rats. Asiaticoside could markedly ameliorate the performance in the Morris Water Maze (decreased latency time and path length, and increased time spent in the target quadrant), which was correlated with its capabilities of suppressing oxidative stress, restoring Na(+)-K(+)-ATPase activity and protecting hippocampal synapses. In vitro, asiaticoside could up-regulate synaptic proteins expression via modulating Phosphoinositide 3-kinase (PI3K)/Protein Kinase B(AKT)/Nuclear Factor -kappa B (NF-κB)-mediated inflammatory pathway in SH-SY5Y cells incubated with high glucose chronically. In conclusion, asiaticoside had beneficial effects on the prevention and treatment of diabetes-associated cognitive deficits, which was involved in oxidative stress, PI3K/Akt/NF-κB pathway and synaptic function in the development of cognitive decline induced by diabetes.

  20. Herbacetin induces apoptosis in HepG2 cells: Involvements of ROS and PI3K/Akt pathway.

    PubMed

    Qiao, Yan; Xiang, Qisen; Yuan, Li; Xu, Li; Liu, Zhigang; Liu, Xuebo

    2013-01-01

    Herbacetin (HER) is a natural flavonoid compound that can be extracted from Ramose Scouring Rush Herb, and its biological and pharmacological activities lack of corresponding attention. In this study, the apoptotic effect of HER against the human hepatoma cell line (HepG2) was investigated. The results showed that HepG2 cells apoptosis occurred in a dose-dependent manner within 48h incubated with HER, which was confirmed by DNA fragmentation, nuclear shrinkage, and poly (ADP-ribose) polymerase (PARP) cleavage. HER at 25-100μM induced a mitochondria-dependent apoptotic pathway associated with Bcl-2/Bax ratio decrease, mitochondrial membrane potential (ΔΨ) collapse, cytochrome c release, and caspase-3 activation. Increasing expression of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) was also observed in HER-treated cells. Furthermore, the addition of a ROS inhibitor (N-Acetyl-l-cysteine, NAC) significantly attenuated the apoptosis induced by HER and also blocked the expression of PGC-1α protein. Additionally, HER effectively inhibited the phosphorylation of Akt and the phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002 increased the inhibition effect of HER on Akt phosphorylation. These findings provide evidences that HER induces HepG2 apoptosis in a ROS-mediated mitochondria-dependent manner that correlate with the inactivation of the PI3K/Akt pathway. PMID:23063593

  1. Intestinal trefoil factor activates the PI3K/Akt signaling pathway to protect gastric mucosal epithelium from damage.

    PubMed

    Sun, Zhaorui; Liu, Hongmei; Yang, Zhizhou; Shao, Danbing; Zhang, Wei; Ren, Yi; Sun, Baodi; Lin, Jinfeng; Xu, Min; Nie, Shinan

    2014-09-01

    Intestinal trefoil factor (ITF, also named as trefoil factor 3, TFF3) is a member of the TFF-domain peptide family, which plays an essential role in the regulation of cell survival, cell migration and maintains mucosal epithelial integrity in the gastrointestinal tract. However, the underlying mechanisms and associated molecules remain unclear. The aim of this study was to explore the protective effects of ITF on gastric mucosal epithelium injury and its possible molecular mechanisms of action. In the present study, we show that ITF was able to promote the proliferation and migration of GES-1 cells via a mechanism that involves the PI3K/Akt signaling pathway. Western blot results indicated that ITF induced a dose- and time-dependent increase in the Akt signaling pathway. ITF also plays an essential role in the restitution of GES-1 cell damage induced by lipopolysaccharide (LPS). LPS induced the apoptosis of GES-1 cells, decreased cell viability significantly (P<0.01) and led to epithelial tight junction damage, which is attenuated via ITF treatment. The protective effect of ITF on the integrity of GES-1 was abrogated by inhibition of the PI3K/Akt pathway. Taken together, our results demonstrate that ITF promotes the proliferation and migration of gastric mucosal epithelial cells and preserves gastric mucosal epithelial integrity after damage is mediated by activation of the PI3K/Akt signaling pathway. This study suggested that the PI3K/Akt pathway could act as a key intracellular pathway in the gastric mucosal epithelium that may serve as a therapeutic target to preserve epithelial integrity during injury.

  2. PI-103 and Quercetin Attenuate PI3K-AKT Signaling Pathway in T- Cell Lymphoma Exposed to Hydrogen Peroxide

    PubMed Central

    Maurya, Akhilendra Kumar; Vinayak, Manjula

    2016-01-01

    Phosphatidylinositol 3 kinase—protein kinase B (PI3K-AKT) pathway has been considered as major drug target site due to its frequent activation in cancer. AKT regulates the activity of various targets to promote tumorigenesis and metastasis. Accumulation of reactive oxygen species (ROS) has been linked to oxidative stress and regulation of signaling pathways for metabolic adaptation of tumor microenvironment. Hydrogen peroxide (H2O2) in this context is used as ROS source for oxidative stress preconditioning. Antioxidants are commonly considered to be beneficial to reduce detrimental effects of ROS and are recommended as dietary supplements. Quercetin, a ubiquitous bioactive flavonoid is a dietary component which has attracted much of interest due to its potential health-promoting effects. Present study is aimed to analyze PI3K-AKT signaling pathway in H2O2 exposed Dalton’s lymphoma ascite (DLA) cells. Further, regulation of PI3K-AKT pathway by quercetin as well as PI-103, an inhibitor of PI3K was analyzed. Exposure of H2O2 (1mM H2O2 for 30min) to DLA cells caused ROS accumulation and resulted in increased phosphorylation of PI3K and downstream proteins PDK1 and AKT (Ser-473 and Thr-308), cell survival factors BAD and ERK1/2, as well as TNFR1. However, level of tumor suppressor PTEN was declined. Both PI-103 & quercetin suppressed the enhanced level of ROS and significantly down-regulated phosphorylation of AKT, PDK1, BAD and level of TNFR1 as well as increased the level of PTEN in H2O2 induced lymphoma cells. The overall result suggests that quercetin and PI3K inhibitor PI-103 attenuate PI3K-AKT pathway in a similar mechanism. PMID:27494022

  3. Comparative analysis of MAPK and PI3K/AKT pathway activation and inhibition in human and canine melanoma.

    PubMed

    Fowles, J S; Denton, C L; Gustafson, D L

    2015-09-01

    The lack of advanced animal models of human cancers is considered a barrier to developing effective therapeutics. Canine and human melanomas are histologically disparate but show similar disease progression and response to therapies. The purpose of these studies was to compare human and canine melanoma tumours and cell lines regarding MAPK and PI3K/AKT signalling dysregulation, and response to select molecularly targeted agents. Pathway activation was investigated via microarray and mutational analysis. Growth inhibition and cell cycle effects were assessed for pathway inhibitors AZD6244 (MAPK) and rapamycin (PI3K/AKT) in human and canine melanoma cells. Human and canine melanoma share similar differential gene expression patterns within the MAPK and PI3K/AKT pathways. Constitutive pathway activation and similar sensitivity to AZD6244 and rapamycin was observed in human and canine cells. These results show that human and canine melanoma share activation and sensitivity to inhibition of cancer-related signalling pathways despite differences in activating mutations. PMID:23745794

  4. The role of the PI3K/Akt/mTOR pathway in glial scar formation following spinal cord injury.

    PubMed

    Chen, Chun-Hong; Sung, Chun-Sung; Huang, Shi-Ying; Feng, Chien-Wei; Hung, Han-Chun; Yang, San-Nan; Chen, Nan-Fu; Tai, Ming-Hong; Wen, Zhi-Hong; Chen, Wu-Fu

    2016-04-01

    Several studies suggest that glial scars pose as physical and chemical barriers that limit neurite regeneration after spinal cord injury (SCI). Evidences suggest that the activation of the PI3K/Akt/mTOR signaling pathway is involved in glial scar formation. Therefore, inhibition of the PI3K/Akt/mTOR pathway may beneficially attenuate glial scar formation after SCI. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) negatively regulates the PI3K/Akt/mTOR pathway. Therefore, we hypothesized that the overexpression of PTEN in the spinal cord will have beneficial effects after SCI. In the present study, we intrathecally injected a recombinant adenovirus carrying the pten gene (Ad-PTEN) to cause overexpression of PTEN in rats with contusion injured spinal cords. The results suggest overexpression of PTEN in spinal cord attenuated glial scar formation and led to improved locomotor function after SCI. Overexpression of PTEN following SCI attenuated gliosis, affected chondroitin sulfate proteoglycan expression, and improved axon regeneration into the lesion site. Furthermore, we suggest that the activation of the PI3K/Akt/mTOR pathway in astrocytes at 3 days after SCI may be involved in glial scar formation. Because delayed treatment with Ad-PTEN enhanced motor function recovery more significantly than immediate treatment with Ad-PTEN after SCI, the results suggest that the best strategy to attenuate glial scar formation could be to introduce 3 days after SCI. This study's findings thus have positive implications for patients who are unable to receive immediate medical attention after SCI. PMID:26828688

  5. Targeting the PI3K/Akt pathway in murine MDS/MPN driven by hyperactive Ras

    PubMed Central

    Akutagawa, Jon; Huang, Tannie Q.; Epstein, Inbal; Chang, Tiffany; Quirindongo-Crespo, Maricel; Cottonham, Charisa L.; Dail, Monique; Slusher, Barbara S.; Friedman, Lori S.; Sampath, Deepak; Braun, Benjamin S.

    2016-01-01

    Chronic and juvenile myelomonocytic leukemias (CMML and JMML) are myelodysplastic/myeloproliferative neoplasia (MDS/MPN) overlap syndromes that respond poorly to conventional treatments. Aberrant Ras activation due to NRAS, KRAS, PTPN11, CBL, and NF1 mutations is common in CMML and JMML. However, no mechanism-based treatments currently exist for cancers with any of these mutations. An alternative therapeutic strategy involves targeting Ras-regulated effector pathways that are aberrantly activated in CMML and JMML, which include the Raf/MEK/ERK and phosphoinositide-3´-OH kinase (PI3K)/Akt cascades. Mx1-Cre, KrasD12 and Mx1-Cre, Nf1flox/− mice accurately model many aspects of CMML and JMML. Treating Mx1-Cre, KrasD12 mice with GDC-0941 (also referred to as pictilisib), an orally bioavailable inhibitor of class I PI3K isoforms, reduced leukocytosis, anemia, and splenomegaly while extending survival. However, GDC-0941 treatment attenuated activation of both PI3K/Akt and Raf/MEK/ERK pathways in primary hematopoietic cells, suggesting it could be acting through suppression of Raf/MEK/ERK signals. To interrogate the importance of the PI3K/Akt pathway specifically, we treated mice with the allosteric Akt inhibitor MK-2206. This compound had no effect on Raf/MEK/ERK signaling, yet it also induced robust hematologic responses in Kras and Nf1 mice with MPN. These data support investigating PI3K/Akt pathway inhibitors as a therapeutic strategy in JMML and CMML patients. PMID:26965285

  6. A natural diarylheptanoid promotes neuronal differentiation via activating ERK and PI3K-Akt dependent pathways.

    PubMed

    Tang, G; Dong, X; Huang, X; Huang, X-J; Liu, H; Wang, Y; Ye, W-C; Shi, L

    2015-09-10

    Neuronal differentiation is a critical developmental process that determines accurate synaptic connection and circuit wiring. A wide variety of naturally occurring compounds have been shown as promising drug leads for the generation and differentiation of neurons. Here we report that a diarylheptanoid from the plant Alpinia officinarum, 7-(4-hydroxyphenyl)-1-phenyl-4E-hepten-3-one (Cpd 1), exhibited potent activities in neuronal differentiation and neurite outgrowth. Cpd 1 induced differentiation of neuroblastoma Neuro-2a cells into a neuron-like morphology, and accelerated the establishment of axon-dendrite polarization of cultured hippocampal neurons. Moreover, Cpd 1 promoted neurite extension in both Neuro-2a cells and neurons. We showed that the effects of Cpd 1 on neuronal differentiation and neurite growth were specifically dependent on the activation of extracellular signal-regulated kinases (ERKs) and phosphoinositide 3-kinase (PI3K)-Akt signaling pathways. Importantly, intraperitoneal administration of Cpd 1 promoted the differentiation of new-born progenitor cells into mature neurons in the adult hippocampal dentate gyrus. Collectively, this study identifies a naturally occurring diarylheptanoid with beneficial effects on neuronal differentiation and neurite outgrowth in vitro and in vivo.

  7. Arctigenin Increases Hemeoxygenase-1 Gene Expression by Modulating PI3K/AKT Signaling Pathway in Rat Primary Astrocytes.

    PubMed

    Jeong, Yeon-Hui; Park, Jin-Sun; Kim, Dong-Hyun; Kim, Hee-Sun

    2014-11-01

    In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-Jun to the antioxidant response element (ARE) on HO-1 promoter. In addition, arctigenin increased ARE-mediated transcriptional activities in rat primary astrocytes. Further mechanistic studies revealed that arctigenin increased the phosphorylation of AKT, a downstream substrate of phosphatidylinositol 3-kinase (PI3K). Treatment of cells with a PI3K-specific inhibitor, LY294002, suppressed the HO-1 expression, Nrf2 DNA binding and ARE-mediated transcriptional activities in arctigenin-treated astrocyte cells. The results collectively suggest that PI3K/AKT signaling pathway is at least partly involved in HO-1 expression by arctigenin via modulation of Nrf2/ARE axis in rat primary astrocytes.

  8. Girdin regulates the migration and invasion of glioma cells via the PI3K-Akt signaling pathway

    PubMed Central

    NI, WEIMIN; FANG, YAN; TONG, LEI; TONG, ZHAOXUE; YI, FUXIN; QIU, JIANWU; WANG, RUI; TONG, XIAOJIE

    2015-01-01

    Girdin, an actin-binding protein, is associated with cell migration and is expressed at high levels in glioma cells. However, the association between girdin and the development of glioma remains to be elucidated. In the present study, short-hairpin RNA technology was used to silence the gene expression of girdin. The effects of girdin silencing on glioma cell proliferation, migration and invasion were then assessed using a cell viability assay, wound-healing assay, transwell invasion assay, reverse transcription-quantitative polymerase chain reaction, western blot analysis and gelatin zymography. The results suggested that girdin silencing inhibited the proliferation, migration and invasion of glioma cells. In addition, the expression levels and activity of matrix metalloproteinase (MMP)-2 and MMP-9 were also affected by girdin silencing. Further mechanistic investigation indicated that girdin may regulate glioma cell migration and invasion through the phosphatidylinositol-3-kinase/protein kinase B (PI3K-Akt) signaling pathway. Therefore, the results of the present study provide a theoretical foundation for the development of anticancer drugs. PMID:26151295

  9. Arctigenin Increases Hemeoxygenase-1 Gene Expression by Modulating PI3K/AKT Signaling Pathway in Rat Primary Astrocytes.

    PubMed

    Jeong, Yeon-Hui; Park, Jin-Sun; Kim, Dong-Hyun; Kim, Hee-Sun

    2014-11-01

    In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-Jun to the antioxidant response element (ARE) on HO-1 promoter. In addition, arctigenin increased ARE-mediated transcriptional activities in rat primary astrocytes. Further mechanistic studies revealed that arctigenin increased the phosphorylation of AKT, a downstream substrate of phosphatidylinositol 3-kinase (PI3K). Treatment of cells with a PI3K-specific inhibitor, LY294002, suppressed the HO-1 expression, Nrf2 DNA binding and ARE-mediated transcriptional activities in arctigenin-treated astrocyte cells. The results collectively suggest that PI3K/AKT signaling pathway is at least partly involved in HO-1 expression by arctigenin via modulation of Nrf2/ARE axis in rat primary astrocytes. PMID:25489416

  10. Arctigenin Increases Hemeoxygenase-1 Gene Expression by Modulating PI3K/AKT Signaling Pathway in Rat Primary Astrocytes

    PubMed Central

    Jeong, Yeon-Hui; Park, Jin-Sun; Kim, Dong-Hyun; Kim, Hee-Sun

    2014-01-01

    In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-Jun to the antioxidant response element (ARE) on HO-1 promoter. In addition, arctigenin increased ARE-mediated transcriptional activities in rat primary astrocytes. Further mechanistic studies revealed that arctigenin increased the phosphorylation of AKT, a downstream substrate of phosphatidylinositol 3-kinase (PI3K). Treatment of cells with a PI3K-specific inhibitor, LY294002, suppressed the HO-1 expression, Nrf2 DNA binding and ARE-mediated transcriptional activities in arctigenin-treated astrocyte cells. The results collectively suggest that PI3K/AKT signaling pathway is at least partly involved in HO-1 expression by arctigenin via modulation of Nrf2/ARE axis in rat primary astrocytes. PMID:25489416

  11. Higher risk of infections with PI3K-AKT-mTOR pathway inhibitors in patients with advanced solid tumors on Phase I clinical trials

    PubMed Central

    Rafii, Saeed; Roda, Desamparados; Geuna, Elena; Jimenez, Begona; Rihawi, Karim; Capelan, Marta; Yap, Timothy A; Molife, L Rhoda; Kaye, Stanley B; de Bono, Johann S; Banerji, Udai

    2015-01-01

    Novel antitumor therapies against the PI3K-AKT-mTOR pathway are increasingly used to treat cancer, either as single agents or in combination with chemotherapy or other targeted therapies. Although these agents are not known to be myelosuppressive, an increased risk of infection has been reported with rapamycin analogs. However, the risk of infection with new inhibitors of this pathway such as PI3K, AKT, mTORC 1/2 or multi-kinase inhibitors is unknown. Methods In this retrospective case-control study, we determined the incidence of infection in a group of 432 patients who were treated on 15 phase I clinical trials involving PI3K-AKT-mTOR pathway inhibitors (cases) vs a group of 100 patients on 10 phase I clinical trials of single agent non-PI3K-AKT-mTOR pathway inhibitors (controls) which did not involve conventional cytotoxic agents. We also collected data from 42 patients who were treated with phase I trials of combinations of PI3K-AKT-mTOR inhibitors and MEK inhibitors and 24 patients with combinations of PI3K-AKT-mTOR inhibitors and cytotoxic chemotherapies. Results The incidence of all grade infection was significantly higher with all single agent PI3K-AKT-mTOR inhibitors compared to the control group (27% vs 8% respectively, OR: 4.26, 95% CI: 1.9-9.1, p=0.0001). The incidence of grade 3 and 4 infection was also significantly higher with PI3K-AKT-mTOR inhibitors compared to the control group (10.3% vs 3%, OR: 3.74, 95% CI: 1.1-12.4, p=0.02). Also the combination of PI3K-AKT-mTOR inhibitors and chemotherapy was associated with a significantly higher incidence of all grade (OR: 4.79, 95% CI: 2.0-11.2, p=0.0001) and high grade (OR: 2.87, 95% CI: 1.0-7.6, p=0.03) infection when compared with single agent PI3K-AKT-mTOR inhibitors. Conclusion Inhibitors of the PI3K-AKT-mTOR pathway can be associated with a higher risk of infection. Combinations of PI3K-AKT-mTOR inhibitors and cytotoxic chemotherapy significantly increase the risk of infection. This should be taken

  12. Wortmannin, PI3K/Akt signaling pathway inhibitor, attenuates thyroid injury associated with severe acute pancreatitis in rats.

    PubMed

    Abliz, Ablikim; Deng, Wenhong; Sun, Rongze; Guo, Wenyi; Zhao, Liang; Wang, Weixing

    2015-01-01

    Increasing evidences suggest that PI3K/AKT pathway plays an important role in the pathogenesis of inflammatory diseases such as acute pancreatitis. However, the exact effect of PI3K/AKT on thyroid injury associated with acute pancreatitis has not been investigated. This study aimed to investigate the protective effects of wortmannin, PI3K/AKT inhibitor, on thyroid injury in a rat model of severe acute pancreatitis (SAP). Sixty male SD rats were randomly divided into four groups: sham operating group (SO), SAP group, wortmannin treatment (WOR) group and drug control (WOR-CON) group. Serum amylase (AMY), lipase (LIP) and thyroid hormone levels were evaluated. The morphological change of thyroid tissue was analyzed under the light and transmission electron microscopy. AKT, P38MAPK and NF-κB expression in the thyroid tissue was evaluated by immunohistochemical staining. Oxidative stress and inflammatory cytokines were detected. Results showed that wortmannin attenuated the following: (1) serum AMY, LIP and thyroid hormone (2) pancreatic and thyroid pathological injuries (3) thyroid MDA, (4) thyroid ultrastructural change, (5) serum TNF-α, IL-6 and IL-1β (6) AKT, MAPKP38 and NF-κB expression in thyroid tissues. These results suggested that wortmannin attenuates thyroid injury in SAP rats, presumably because of its role on prevent ROS generation and inhibits the activation of P38MAPK, NF-κB pathway. Our findings provide new therapeutic targets for thyroid injury associated with SAP. PMID:26823696

  13. PTEN posttranslational inactivation and hyperactivation of the PI3K/Akt pathway sustain primary T cell leukemia viability

    PubMed Central

    Silva, Ana; Yunes, J. Andrés; Cardoso, Bruno A.; Martins, Leila R.; Jotta, Patrícia Y.; Abecasis, Miguel; Nowill, Alexandre E.; Leslie, Nick R.; Cardoso, Angelo A.; Barata, Joao T.

    2008-01-01

    Mutations in the phosphatase and tensin homolog (PTEN) gene leading to PTEN protein deletion and subsequent activation of the PI3K/Akt signaling pathway are common in cancer. Here we show that PTEN inactivation in human T cell acute lymphoblastic leukemia (T-ALL) cells is not always synonymous with PTEN gene lesions and diminished protein expression. Samples taken from patients with T-ALL at the time of diagnosis very frequently showed constitutive hyperactivation of the PI3K/Akt pathway. In contrast to immortalized cell lines, most primary T-ALL cells did not harbor PTEN gene alterations, displayed normal PTEN mRNA levels, and expressed higher PTEN protein levels than normal T cell precursors. However, PTEN overexpression was associated with decreased PTEN lipid phosphatase activity, resulting from casein kinase 2 (CK2) overexpression and hyperactivation. In addition, T-ALL cells had constitutively high levels of ROS, which can also downmodulate PTEN activity. Accordingly, both CK2 inhibitors and ROS scavengers restored PTEN activity and impaired PI3K/Akt signaling in T-ALL cells. Strikingly, inhibition of PI3K and/or CK2 promoted T-ALL cell death without affecting normal T cell precursors. Overall, our data indicate that T-ALL cells inactivate PTEN mostly in a nondeletional, posttranslational manner. Pharmacological manipulation of these mechanisms may open new avenues for T-ALL treatment. PMID:18830414

  14. Wortmannin, PI3K/Akt signaling pathway inhibitor, attenuates thyroid injury associated with severe acute pancreatitis in rats.

    PubMed

    Abliz, Ablikim; Deng, Wenhong; Sun, Rongze; Guo, Wenyi; Zhao, Liang; Wang, Weixing

    2015-01-01

    Increasing evidences suggest that PI3K/AKT pathway plays an important role in the pathogenesis of inflammatory diseases such as acute pancreatitis. However, the exact effect of PI3K/AKT on thyroid injury associated with acute pancreatitis has not been investigated. This study aimed to investigate the protective effects of wortmannin, PI3K/AKT inhibitor, on thyroid injury in a rat model of severe acute pancreatitis (SAP). Sixty male SD rats were randomly divided into four groups: sham operating group (SO), SAP group, wortmannin treatment (WOR) group and drug control (WOR-CON) group. Serum amylase (AMY), lipase (LIP) and thyroid hormone levels were evaluated. The morphological change of thyroid tissue was analyzed under the light and transmission electron microscopy. AKT, P38MAPK and NF-κB expression in the thyroid tissue was evaluated by immunohistochemical staining. Oxidative stress and inflammatory cytokines were detected. Results showed that wortmannin attenuated the following: (1) serum AMY, LIP and thyroid hormone (2) pancreatic and thyroid pathological injuries (3) thyroid MDA, (4) thyroid ultrastructural change, (5) serum TNF-α, IL-6 and IL-1β (6) AKT, MAPKP38 and NF-κB expression in thyroid tissues. These results suggested that wortmannin attenuates thyroid injury in SAP rats, presumably because of its role on prevent ROS generation and inhibits the activation of P38MAPK, NF-κB pathway. Our findings provide new therapeutic targets for thyroid injury associated with SAP.

  15. Ethosuximide Induces Hippocampal Neurogenesis and Reverses Cognitive Deficits in an Amyloid-β Toxin-induced Alzheimer Rat Model via the Phosphatidylinositol 3-Kinase (PI3K)/Akt/Wnt/β-Catenin Pathway.

    PubMed

    Tiwari, Shashi Kant; Seth, Brashket; Agarwal, Swati; Yadav, Anuradha; Karmakar, Madhumita; Gupta, Shailendra Kumar; Choubey, Vinay; Sharma, Abhay; Chaturvedi, Rajnish Kumar

    2015-11-20

    Neurogenesis involves generation of new neurons through finely tuned multistep processes, such as neural stem cell (NSC) proliferation, migration, differentiation, and integration into existing neuronal circuitry in the dentate gyrus of the hippocampus and subventricular zone. Adult hippocampal neurogenesis is involved in cognitive functions and altered in various neurodegenerative disorders, including Alzheimer disease (AD). Ethosuximide (ETH), an anticonvulsant drug is used for the treatment of epileptic seizures. However, the effects of ETH on adult hippocampal neurogenesis and the underlying cellular and molecular mechanism(s) are yet unexplored. Herein, we studied the effects of ETH on rat multipotent NSC proliferation and neuronal differentiation and adult hippocampal neurogenesis in an amyloid β (Aβ) toxin-induced rat model of AD-like phenotypes. ETH potently induced NSC proliferation and neuronal differentiation in the hippocampus-derived NSC in vitro. ETH enhanced NSC proliferation and neuronal differentiation and reduced Aβ toxin-mediated toxicity and neurodegeneration, leading to behavioral recovery in the rat AD model. ETH inhibited Aβ-mediated suppression of neurogenic and Akt/Wnt/β-catenin pathway gene expression in the hippocampus. ETH activated the PI3K·Akt and Wnt·β-catenin transduction pathways that are known to be involved in the regulation of neurogenesis. Inhibition of the PI3K·Akt and Wnt·β-catenin pathways effectively blocked the mitogenic and neurogenic effects of ETH. In silico molecular target prediction docking studies suggest that ETH interacts with Akt, Dkk-1, and GSK-3β. Our findings suggest that ETH stimulates NSC proliferation and differentiation in vitro and adult hippocampal neurogenesis via the PI3K·Akt and Wnt·β-catenin signaling.

  16. Ethosuximide Induces Hippocampal Neurogenesis and Reverses Cognitive Deficits in an Amyloid-β Toxin-induced Alzheimer Rat Model via the Phosphatidylinositol 3-Kinase (PI3K)/Akt/Wnt/β-Catenin Pathway.

    PubMed

    Tiwari, Shashi Kant; Seth, Brashket; Agarwal, Swati; Yadav, Anuradha; Karmakar, Madhumita; Gupta, Shailendra Kumar; Choubey, Vinay; Sharma, Abhay; Chaturvedi, Rajnish Kumar

    2015-11-20

    Neurogenesis involves generation of new neurons through finely tuned multistep processes, such as neural stem cell (NSC) proliferation, migration, differentiation, and integration into existing neuronal circuitry in the dentate gyrus of the hippocampus and subventricular zone. Adult hippocampal neurogenesis is involved in cognitive functions and altered in various neurodegenerative disorders, including Alzheimer disease (AD). Ethosuximide (ETH), an anticonvulsant drug is used for the treatment of epileptic seizures. However, the effects of ETH on adult hippocampal neurogenesis and the underlying cellular and molecular mechanism(s) are yet unexplored. Herein, we studied the effects of ETH on rat multipotent NSC proliferation and neuronal differentiation and adult hippocampal neurogenesis in an amyloid β (Aβ) toxin-induced rat model of AD-like phenotypes. ETH potently induced NSC proliferation and neuronal differentiation in the hippocampus-derived NSC in vitro. ETH enhanced NSC proliferation and neuronal differentiation and reduced Aβ toxin-mediated toxicity and neurodegeneration, leading to behavioral recovery in the rat AD model. ETH inhibited Aβ-mediated suppression of neurogenic and Akt/Wnt/β-catenin pathway gene expression in the hippocampus. ETH activated the PI3K·Akt and Wnt·β-catenin transduction pathways that are known to be involved in the regulation of neurogenesis. Inhibition of the PI3K·Akt and Wnt·β-catenin pathways effectively blocked the mitogenic and neurogenic effects of ETH. In silico molecular target prediction docking studies suggest that ETH interacts with Akt, Dkk-1, and GSK-3β. Our findings suggest that ETH stimulates NSC proliferation and differentiation in vitro and adult hippocampal neurogenesis via the PI3K·Akt and Wnt·β-catenin signaling. PMID:26420483

  17. Hedgehog signaling is a novel therapeutic target in tamoxifen-resistant breast cancer aberrantly activated by PI3K/AKT pathway.

    PubMed

    Ramaswamy, Bhuvaneswari; Lu, Yuanzhi; Teng, Kun-yu; Nuovo, Gerard; Li, Xiaobai; Shapiro, Charles L; Majumder, Sarmila

    2012-10-01

    Endocrine resistance is a major challenge in the management of estrogen receptor (ER)-positive breast cancers. Although multiple mechanisms leading to endocrine resistance have been proposed, the poor outcome of patients developing resistance to endocrine therapy warrants additional studies. Here we show that noncanonical Hedgehog (Hh) signaling is an alternative growth promoting mechanism that is activated in tamoxifen-resistant tumors. Importantly, phosphoinositide 3-kinase inhibitor/protein kinase B (PI3K/AKT) pathway plays a key role in regulating Hh signaling by protecting key components of this pathway from proteasomal degradation. The levels of Hh-signaling molecules SMO and GLI1 and the targets were significantly elevated in tamoxifen-resistant MCF-7 cells and T47D cells. Serial passage of the resistant cells in mice resulted in aggressive tumors that metastasized to distant organs with concurrent increases in Hh marker expression and epithelial mesenchymal transition. RNAi-mediated depletion of SMO or GLI1 in the resistant cells resulted in reduced proliferation, clonogenic survival and delayed G(1)-S transition. Notably, treatment of resistant cells with PI3K inhibitors decreased SMO and GLI1 protein levels and activity that was rescued upon blocking GSK3β and proteasomal degradation. Furthermore, treatment of tamoxifen-resistant xenografts with anti-Hh compound GDC-0449 blocked tumor growth in mice. Importantly, high GLI1 expression correlated inversely with disease-free and overall survival in a cohort of 315 patients with breast cancer. In summary, our results describe a signaling event linking PI3K/AKT pathway with Hh signaling that promotes tamoxifen resistance. Targeting Hh pathway alone or in combination with PI3K/AKT pathway could therefore be a novel therapeutic option in treating endocrine-resistant breast cancer.

  18. Silica nanoparticles induce autophagy and endothelial dysfunction via the PI3K/Akt/mTOR signaling pathway.

    PubMed

    Duan, Junchao; Yu, Yongbo; Yu, Yang; Li, Yang; Wang, Ji; Geng, Weijia; Jiang, Lizhen; Li, Qiuling; Zhou, Xianqing; Sun, Zhiwei

    2014-01-01

    Although nanoparticles have a great potential for biomedical applications, there is still a lack of a correlative safety evaluation on the cardiovascular system. This study is aimed to clarify the biological behavior and influence of silica nanoparticles (Nano-SiO2) on endothelial cell function. The results showed that the Nano-SiO2 were internalized into endothelial cells in a dose-dependent manner. Monodansylcadaverine staining, autophagic ultrastructural observation, and LC3-I/LC3-II conversion were employed to verify autophagy activation induced by Nano-SiO2, and the whole autophagic process was also observed in endothelial cells. In addition, the level of nitric oxide (NO), the activities of NO synthase (NOS) and endothelial (e)NOS were significantly decreased in a dose-dependent way, while the activity of inducible (i)NOS was markedly increased. The expression of C-reactive protein, as well as the production of proinflammatory cytokines (tumor necrosis factor α, interleukin [IL]-1β, and IL-6) were significantly elevated. Moreover, Nano-SiO2 had an inhibitory effect on the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. Our findings demonstrated that Nano-SiO2 could disturb the NO/NOS system, induce inflammatory response, activate autophagy, and eventually lead to endothelial dysfunction via the PI3K/Akt/mTOR pathway. This indicates that exposure to Nano-SiO2 is a potential risk factor for cardiovascular diseases.

  19. Dual inhibition of CDK4/Rb and PI3K/AKT/mTOR pathways by ON123300 induces synthetic lethality in mantle cell lymphomas.

    PubMed

    Divakar, S K A; Ramana Reddy, M V; Cosenza, S C; Baker, S J; Perumal, D; Antonelli, A C; Brody, J; Akula, B; Parekh, S; Reddy, E Premkumar

    2016-01-01

    This study describes the characterization of a novel kinase inhibitor, ON123300, which inhibits CDK4/6 (cyclin-dependent kinases 4 and 6) and phosphatidylinositol 3 kinase-δ (PI3K-δ) and exhibits potent activity against mantle cell lymphomas (MCLs) both in vitro and in vivo. We examined the effects of PD0332991 and ON123300 on cell cycle progression, modulation of the retinoblastoma (Rb) and PI3K/AKT pathways, and the induction of apoptosis in MCL cell lines and patient-derived samples. When Granta 519 and Z138C cells were incubated with PD0332991 and ON123300, both compounds were equally efficient in their ability to inhibit the phosphorylation of Rb family proteins. However, only ON123300 inhibited the phosphorylation of proteins associated with the PI3K/AKT pathway. Cells treated with PD0332991 rapidly accumulated in the G0/G1 phase of cell cycle as a function of increasing concentration. Although ON123300-treated cells arrested similarly at lower concentrations, higher concentrations resulted in the induction of apoptosis, which was not observed in PD0332991-treated samples. Mouse xenograft assays also showed a strong inhibition of MCL tumor growth in ON123300-treated animals. Finally, treatment of ibrutinib-sensitive and -resistant patient-derived MCLs with ON123300 also triggered apoptosis and inhibition of the Rb and PI3K/AKT pathways, suggesting that this compound might be an effective agent in MCL, including ibrutinib-resistant forms of the disease. PMID:26174628

  20. The Role of EGFR/PI3K/Akt/cyclinD1 Signaling Pathway in Acquired Middle Ear Cholesteatoma

    PubMed Central

    Liu, Wei; Ren, Hongmiao; Ren, Jihao; Yin, Tuanfang; Hu, Bing; Xie, Shumin; Dai, Yinghuan; Wu, Weijing; Xiao, Zian; Yang, Xinming; Xie, Dinghua

    2013-01-01

    Cholesteatoma is a benign keratinizing and hyper proliferative squamous epithelial lesion of the temporal bone. Epidermal growth factor (EGF) is one of the most important cytokines which has been shown to play a critical role in cholesteatoma. In this investigation, we studied the effects of EGF on the proliferation of keratinocytes and EGF-mediated signaling pathways underlying the pathogenesis of cholesteatoma. We examined the expressions of phosphorylated EGF receptor (p-EGFR), phosphorylated Akt (p-Akt), cyclinD1, and proliferating cell nuclear antigen (PCNA) in 40 cholesteatoma samples and 20 samples of normal external auditory canal (EAC) epithelium by immunohistochemical method. Furthermore, in vitro studies were performed to investigate EGF-induced downstream signaling pathways in primary external auditory canal keratinocytes (EACKs). The expressions of p-EGFR, p-Akt, cyclinD1, and PCNA in cholesteatoma epithelium were significantly increased when compared with those of control subjects. We also demonstrated that EGF led to the activation of the EGFR/PI3K/Akt/cyclinD1 signaling pathway, which played a critical role in EGF-induced cell proliferation and cell cycle progression of EACKs. Both EGFR inhibitor AG1478 and PI3K inhibitor wortmannin inhibited the EGF-induced EGFR/PI3K/Akt/cyclinD1 signaling pathway concomitantly with inhibition of cell proliferation and cell cycle progression of EACKs. Taken together, our data suggest that the EGFR/PI3K/Akt/cyclinD1 signaling pathway is active in cholesteatoma and may play a crucial role in cholesteatoma epithelial hyper-proliferation. This study will facilitate the development of potential therapeutic targets for intratympanic drug therapy for cholesteatoma. PMID:24311896

  1. Cinnamaldehyde affects the biological behavior of human colorectal cancer cells and induces apoptosis via inhibition of the PI3K/Akt signaling pathway.

    PubMed

    Li, Jiepin; Teng, Yuhao; Liu, Shenlin; Wang, Zifan; Chen, Yan; Zhang, Yingying; Xi, Songyang; Xu, Song; Wang, Ruiping; Zou, Xi

    2016-03-01

    Cinnamaldehyde (CA) is a bioactive compound isolated from the stem bark of Cinnamomum cassia, that has been identified as an antiproliferative substance with pro-apoptotic effects on various cancer cell lines in vitro. In the present study, the effects of CA on human colon cancer cells were investigated at both the molecular and cellular levels. Three types of colorectal cancer cells at various stages of differentiation and invasive ability (SW480, HCT116 and LoVo) were treated with CA at final concentrations of 20, 40 and 80 µg/ml for 24 h. Compared with the control group, the proliferation inhibition rate of the human colorectal cancer cells following treatment with CA increased in a dose- and time-dependent manner. The invasion and adhesion abilities of the cells were significantly inhibited as indicated by Transwell and cell-matrix adhesion assays. Meanwhile, CA also upregulated the expression of E-cadherin and downregulated the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9. CA also elevated the apoptotic rate. The levels of pro-apoptotic genes were upregulated while the levels of apoptosis inhibitory genes were decreased which further confirmed the pro-apoptotic effect of CA. In order to explore the mechanism of CA-induced apoptosis, insulin-like growth factor-1 (IGF-1) and PI3K inhibitor (LY294002) were used to regulate the phosphoinositide 3-kinase (PI3K)/AKT pathway. The transcription activity of PI3K/AKT was markedly inhibited by CA, as well as IGF-1 which functions as an anti-apoptotic factor. In conclusion, CA has the potential to be developed as a new antitumor drug. The mechanisms of action involve the regulation of expression of genes involved in apoptosis, invasion and adhesion via inhibition of the PI3K/Akt signaling pathway. PMID:26677144

  2. Cinnamaldehyde affects the biological behavior of human colorectal cancer cells and induces apoptosis via inhibition of the PI3K/Akt signaling pathway.

    PubMed

    Li, Jiepin; Teng, Yuhao; Liu, Shenlin; Wang, Zifan; Chen, Yan; Zhang, Yingying; Xi, Songyang; Xu, Song; Wang, Ruiping; Zou, Xi

    2016-03-01

    Cinnamaldehyde (CA) is a bioactive compound isolated from the stem bark of Cinnamomum cassia, that has been identified as an antiproliferative substance with pro-apoptotic effects on various cancer cell lines in vitro. In the present study, the effects of CA on human colon cancer cells were investigated at both the molecular and cellular levels. Three types of colorectal cancer cells at various stages of differentiation and invasive ability (SW480, HCT116 and LoVo) were treated with CA at final concentrations of 20, 40 and 80 µg/ml for 24 h. Compared with the control group, the proliferation inhibition rate of the human colorectal cancer cells following treatment with CA increased in a dose- and time-dependent manner. The invasion and adhesion abilities of the cells were significantly inhibited as indicated by Transwell and cell-matrix adhesion assays. Meanwhile, CA also upregulated the expression of E-cadherin and downregulated the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9. CA also elevated the apoptotic rate. The levels of pro-apoptotic genes were upregulated while the levels of apoptosis inhibitory genes were decreased which further confirmed the pro-apoptotic effect of CA. In order to explore the mechanism of CA-induced apoptosis, insulin-like growth factor-1 (IGF-1) and PI3K inhibitor (LY294002) were used to regulate the phosphoinositide 3-kinase (PI3K)/AKT pathway. The transcription activity of PI3K/AKT was markedly inhibited by CA, as well as IGF-1 which functions as an anti-apoptotic factor. In conclusion, CA has the potential to be developed as a new antitumor drug. The mechanisms of action involve the regulation of expression of genes involved in apoptosis, invasion and adhesion via inhibition of the PI3K/Akt signaling pathway.

  3. Mango polyphenolics suppressed tumor growth in breast cancer xenografts in mice: role of the PI3K/AKT pathway and associated microRNAs.

    PubMed

    Banerjee, Nivedita; Kim, Hyemee; Krenek, Kimberly; Talcott, Stephen T; Mertens-Talcott, Susanne U

    2015-08-01

    The cytotoxic and anti-inflammatory properties of mango polyphenolics including gallic acid and gallotannins have been demonstrated in numerous types of cancers. We hypothesized that the phosphoinositide 3-kinase (PI3K)/AKT pathway and the expression of related miRNAs are involved in the chemotherapeutic activities of mango polyphenolics in a mouse xenograft model for breast cancer. The objectives of this research were to determine the tumor-cytotoxic activities of mango polyphenolics and the underlying molecular mechanisms involving posttranscriptional targets in BT474 breast cancer cells and xenografts in mice. In vitro findings showed cytotoxic effects of mango polyphenolics in BT474 breast cancer cells within a concentration range of 2.5 to 20 mg/L gallic acid equivalents. Mango polyphenolics suppressed the expression of PI3K, AKT, hypoxia inducible factor-1α, and vascular endothelial growth factor (VEGF) mRNA, and pAKT, AKT, pPI3K (p85), VEGF and nuclear factor-kappa B protein levels. The involvement of miR-126 was verified by using antagomiR for miR-126, where mango reversed the effect of the antagomiR of miR-126. In vivo, the intake of mango polyphenolics decreased the tumor volume by 73% in BT474 xenograft-bearing mice compared with the control group. In addition, mango reduced the expression of nuclear factor-kappa B (p65), pAKT, pPI3K, mammalian target of rapamycin, hypoxia inducible factor-1α, and VEGF protein in athymic nude mice. A screening for miRNA expression changes confirmed that mango polyphenolics modulated the expression of cancer-associated miRNAs including miR-126 in the xenografted tumors. In summary, mango polyphenolics have a chemotherapeutic potential against breast cancer that at least in part is mediated through the PI3K/AKT pathway and miR-126.

  4. Therapeutic ultrasound reverses peripheral ischemia in type 2 diabetic mice through PI3K-Akt-eNOS pathway

    PubMed Central

    Lu, Zhao-Yang; Li, Rui-Lin; Zhou, Hong-Sheng; Huang, Jing-Juan; Su, Zhi-Xiao; Qi, Jia; Zhang, Lan; Li, Yue; Shi, Yi-Qin; Hao, Chang-Ning; Duan, Jun-Li

    2016-01-01

    Therapeutic ultrasound (TUS) has been demonstrated to improve endothelial nitric oxide synthase (eNOS) activity, which played a crucial role in the regulation of angiogenesis. Diabetes Mellitus (DM) impairs eNOS activity. We tested the hypothesis that DM may retard unilateral hindlimb ischemia-induced angiogenesis by inhibiting eNOS in high-fat diet (HFD)/streptozocin (STZ) induced diabetic mice, and that TUS may reverse DM-related impairment of angiogenesis. C57BL/6 mice were allocated to four groups: (A) mice were fed standard diet (control); (B) mice were fed standard diet and treated with TUS (control+TUS); (C) type-2 DM mice were induced by HFD/STZ (diabetic); and (D) type-2 DM mice and treated with TUS (dabetic+TUS). All mice were surgically induced unilateral limb ischemia. The ischemic skeletal muscles in groups B and D were irradiated with extracorporeal TUS for 9 minutes/day (frequency of 1 MHz, intensity of 0.3 W/cm2) for 14 consecutive days. The result showed that TUS augmented the blood perfusion, increased capillary density accompanied by an upregulation of angiogenic factors and a downregulation of apoptotic proteins in group D relative to group C. In vitro, TUS inhibited the apoptosis, promoted tubule formation, proliferation and migration capacities, increased angiogenic factors expression and reduced apoptotic protein levels in human umbilical vein endothelial cells (HUVECs). Furthermore, TUS can robust reverse the inhibiting effect induced by high glucose (HG) on HUVECs, and these benefits could be blocked by phosphoinositide 3-kinase (PI3K) inhibitor (LY294002) or eNOS inhibitor (L-NAME). Together, TUS restored type-2 DM-mediated inhibition of ischemia-induced angiogenesis, partially via PI3K-Akt-eNOS signal pathway. PMID:27725849

  5. Treadmill exercise reduces spinal cord injury-induced apoptosis by activating the PI3K/Akt pathway in rats.

    PubMed

    Jung, Sun-Young; Kim, Dae-Young; Yune, Tae Young; Shin, Dong-Hoon; Baek, Sang-Bin; Kim, Chang-Ju

    2014-03-01

    Apoptosis occurring secondary to spinal cord injury (SCI) causes further neural damage and functional loss. In this study, a rat model was used to investigate the effect of treadmill exercise on SCI-induced apoptosis and expression of neurotrophic factors. To produce SCI, a contusion injury (10 g × 25 mm) was applied subsequent to laminectomy at the T9-T10 level. Following SCI, treadmill exercise was performed for six weeks. Hindlimb motor function was evaluated with a grid-walking test. The expression of neurotrophic factors and the level of apoptosis at the site of SCI were determined by western blotting. SCI reduced hindlimb motor function and suppressed expression of neurotrophin (NT)-3 and insulin-like growth factor (IGF)-1. Expression of phosphatidylinositol 3-kinase (PI3K), the ratio of phosphorylated Akt to Akt (pAkt/Akt) and the ratio of B-cell lymphoma 2 (Bcl-2) to Bax (Bcl-2/Bax) were decreased, and cleaved caspase-3 expression was increased by SCI. Treadmill exercise enhanced hindlimb motor function and increased expression of nerve growth factor (NGF), NT-3 and IGF-1 in the SCI rats. Treadmill exercise increased PI3K expression, the pAkt/Akt and the Bcl-2/Bax ratios, and suppressed cleaved caspase-3 expression in the injured spinal cord. This study demonstrated that treadmill exercise promotes the recovery of motor function by suppressing apoptosis in the injured spinal cord. The beneficial effect of exercise may be attributed to the increase in expression of neurotrophic factors via activation of the PI3K/Akt pathway.

  6. Vitamin E succinate induces apoptosis via the PI3K/AKT signaling pathways in EC109 esophageal cancer cells

    PubMed Central

    Yang, Peng; Zhao, Jiaying; Hou, Liying; Yang, Lei; Wu, Kun; Zhang, Linyou

    2016-01-01

    Esophageal cancer is the fourth most common gastrointestinal cancer, it generally has a poor prognosis and novel strategies are required for prevention and treatment. Vitamin E succinate (VES) is a potential chemical agent for cancer prevention and therapy as it exerts anti-tumor effects in a variety of cancers. However, the role of VES in tumorigenesis and progression of cancer remains to be elucidated. The present study aimed to determine the effects of VES in regulating the survival and apoptosis of human esophageal cancer cells. EC109 human esophageal cancer cells were used to investigate the anti-proliferative effects of VES. The MTT and Annexin V-fluorescein isothiocyanate/propidium iodide assays demonstrated that VES inhibited cell proliferation and induced apoptosis in esophageal cancer cells. Furthermore, VES downregulated constitutively active basal levels of phosphorylated (p)-serine-threonine kinase AKT (AKT) and p-mammalian target of rapamycin (mTOR), and decreased the phosphorylation of AKT substrates Bcl-2-associated death receptor and caspase-9, in addition to mTOR effectors, ribosomal protein S6 kinase β1 and eIF4E-binding protein 1. Phosphoinositide-3-kinase (PI3K) inhibitor, LY294002 suppressed p-AKT and p-mTOR, indicating PI3K is a common upstream mediator. The apoptosis induced by VES was increased by inhibition of AKT or mTOR with their respective inhibitor in esophageal cancer cells. The results of the present study suggested that VES targeted the PI3K/AKT signaling pathways and induced apoptosis in esophageal cancer cells. Furthermore, the current study suggests that VES may be useful in a combinational therapeutic strategy employing an mTOR inhibitor. PMID:27357907

  7. Targeting EMP3 suppresses proliferation and invasion of hepatocellular carcinoma cells through inactivation of PI3K/Akt pathway.

    PubMed

    Hsieh, Yi-Hsien; Hsieh, Shu-Ching; Lee, Chien-Hsing; Yang, Shun-Fa; Cheng, Chun-Wen; Tang, Meng-Ju; Lin, Chia-Liang; Lin, Chu-Liang; Chou, Ruey-Hwang

    2015-10-27

    Epithelial membrane protein-3 (EMP3), a typical member of the epithelial membrane protein (EMP) family, is epigenetically silenced in some cancer types, and has been proposed to be a tumor suppressor gene. However, its effects on tumor suppression are controversial and its roles in development and malignancy of hepatocellular carcinoma (HCC) remain unclear. In the present study, we found that EMP3 was highly expressed in the tumorous tissues comparing to the matched normal tissues, and negatively correlated with differentiated degree of HCC patients. Knockdown of EMP3 significantly reduced cell proliferation, arrested cell cycle at G1 phase, and inhibited the motility and invasiveness in accordance with the decreased expression and activity of urokinase plasminogen activator (uPA) and matrix metalloproteinase 9 (MMP-9) in HCC cells. The in vivo tumor growth of HCC was effectively suppressed by knockdown of EMP3 in a xenograft mouse model. The EMP3 knockdown-reduced cell proliferation and invasion were attenuated by inhibition of phosphatidylinositol 3-kinase (PI3K) or knockdown of Akt, and rescued by overexpression of Akt in HCC cells. Clinical positive correlations of EMP3 with p85 regulatory subunit of PI3K, p-Akt, uPA, as well as MMP-9 were observed in the tissue sections from HCC patients. Here, we elucidated the tumor progressive effects of EMP3 through PI3K/Akt pathway and uPA/MMP-9 cascade in HCC cells. The findings provided a new insight into EMP3, which might be a potential molecular target for diagnosis and treatment of HCC. PMID:26472188

  8. Krüppel-like factor 14 increases insulin sensitivity through activation of PI3K/Akt signal pathway.

    PubMed

    Yang, Min; Ren, Yan; Lin, Zhimin; Tang, Chenchen; Jia, Yanjun; Lai, Yerui; Zhou, Tingting; Wu, Shaobo; Liu, Hua; Yang, Gangyi; Li, Ling

    2015-11-01

    Genome-wide association studies (GWAS) have shown that Krüppel-like factor 14 (KLF14) is associated with type 2 diabetes mellitus (T2DM). However, no report has demonstrated a relationship between KLF14 and glucose metabolism. The aim of this study was to determine whether KLF14 is associated with glucose metabolism and insulin signaling in vitro. The mRNA and protein expressions of KLF14 were determined by Real-time PCR and Western blotting. Glucose uptake was assessed by 2-[(3)H]-deoxyglucose (2-DG) uptake. Western blotting was used to identify the activation of insulin signaling proteins. KLF14 mRNA and protein in fat and muscle were significantly decreased in HFD-fed mice, db/db mice and T2DM patients. Overexpression of KLF14 enhanced insulin-stimulated glucose uptake and the activation of Akt kinase in Hepa1-6 cells. The phosphorylation of insulin receptor (InsR), insulin receptor substrate-1(IRS-1), glycogen synthase kinase-3β (GSK-3β) and Akt also elevated significantly by up-regulation of KLF14. KLF14 overexpression in Hepa1-6 cells prevented the inhibition of glucose uptake and Akt phosphorylation induced by high glucose and/or high insulin, or T2DM serum. However, KLF14's ability to increase glucose uptake and Akt activation was significantly attenuated by LY294002, a PI3-kinase inhibitor. These data suggested that KLF14 could increase insulin sensitivity probably through the PI3K/Akt pathway. PMID:26226221

  9. Wogonin inhibits H2O2-induced angiogenesis via suppressing PI3K/Akt/NF-κB signaling pathway.

    PubMed

    Zhou, Mi; Song, Xiuming; Huang, Yujie; Wei, Libin; Li, Zhiyu; You, Qidong; Guo, Qinglong; Lu, Na

    2014-03-01

    Wogonin, a natural monoflavonoid extracted from Scutellariae radix, has been reported for its ability of inhibiting tumor angiogenesis. In this study, we assessed the effect of wogonin on angiogenesis induced by low level of H2O2 (10 μM) in human umbilical vein endothelial cells (HUVECs). Wogonin suppressed H2O2-induced migration and tube formation of HUVECs as well as microvessel sprouting from rat aortic rings in vitro. Meanwhile, wogonin suppressed vessel growth in chicken chorioallantoic membrane (CAM) model in vivo. Mechanistic studies showed that wogonin suppressed H2O2-activated PI3K/Akt pathway and reduced the expression of vascular endothelial growth factor (VEGF) up-regulated by H2O2 in both protein and mRNA levels. In addition, wogonin also inhibited nuclear translocation of NF-κB, and decreased the binding ability of NF-κB with exogenous consensus DNA oligonucleotide. Then we further investigated the effect of wogonin on over-activated PI3K/Akt pathway by insulin-like growth factor-1 (IGF-1) and H2O2. We found that wogonin suppressed phosphorylation of Akt, up-regulation of VEGF and angiogenesis in vitro which was further induced by IGF-1 and H2O2. Moreover, in NF-κB overexpressed HUVECs, wogonin could also reduce the expression of VEGF and inhibited the migration and tube formation. Taken together, these results suggested that wogonin was potential in inhibiting H2O2-induced angiogenesis in vitro and in vivo via suppressing PI3K/Akt pathway and NF-κB signaling.

  10. PI3K/AKT pathway mutations cause a spectrum of brain malformations from megalencephaly to focal cortical dysplasia.

    PubMed

    Jansen, Laura A; Mirzaa, Ghayda M; Ishak, Gisele E; O'Roak, Brian J; Hiatt, Joseph B; Roden, William H; Gunter, Sonya A; Christian, Susan L; Collins, Sarah; Adams, Carissa; Rivière, Jean-Baptiste; St-Onge, Judith; Ojemann, Jeffrey G; Shendure, Jay; Hevner, Robert F; Dobyns, William B

    2015-06-01

    Malformations of cortical development containing dysplastic neuronal and glial elements, including hemimegalencephaly and focal cortical dysplasia, are common causes of intractable paediatric epilepsy. In this study we performed multiplex targeted sequencing of 10 genes in the PI3K/AKT pathway on brain tissue from 33 children who underwent surgical resection of dysplastic cortex for the treatment of intractable epilepsy. Sequencing results were correlated with clinical, imaging, pathological and immunohistological phenotypes. We identified mosaic activating mutations in PIK3CA and AKT3 in this cohort, including cancer-associated hotspot PIK3CA mutations in dysplastic megalencephaly, hemimegalencephaly, and focal cortical dysplasia type IIa. In addition, a germline PTEN mutation was identified in a male with hemimegalencephaly but no peripheral manifestations of the PTEN hamartoma tumour syndrome. A spectrum of clinical, imaging and pathological abnormalities was found in this cohort. While patients with more severe brain imaging abnormalities and systemic manifestations were more likely to have detected mutations, routine histopathological studies did not predict mutation status. In addition, elevated levels of phosphorylated S6 ribosomal protein were identified in both neurons and astrocytes of all hemimegalencephaly and focal cortical dysplasia type II specimens, regardless of the presence or absence of detected PI3K/AKT pathway mutations. In contrast, expression patterns of the T308 and S473 phosphorylated forms of AKT and in vitro AKT kinase activities discriminated between mutation-positive dysplasia cortex, mutation-negative dysplasia cortex, and non-dysplasia epilepsy cortex. Our findings identify PI3K/AKT pathway mutations as an important cause of epileptogenic brain malformations and establish megalencephaly, hemimegalencephaly, and focal cortical dysplasia as part of a single pathogenic spectrum.

  11. Effect of Compound Chuanxiong Capsule on Inflammatory Reaction and PI3K/Akt/NF-κB Signaling Pathway in Atherosclerosis.

    PubMed

    Kang, Qunfu; Liu, Weihong; Liu, Hongxu; Zhou, Mingxue

    2015-01-01

    Compound Chuanxiong Capsule (CCC), a Chinese herbal compound, can exhibit antiatherosclerotic effect; however, its mechanism is still unclear. This study is designed to study the mechanism of CCC on atherosclerosis in the ApoE-knockout (ApoE(-/-)) mice fed with a high-fat diet. After 6 weeks of high-fat feeding, 40 ApoE(-/-) mice were randomized (n = 10) and treated with lipitor, high-dose or low-dose CCC, or distilled water (ApoE(-/-) group) for 7 weeks. The blood lipids in serum and the plaque areas of the mice were measured and the mRNA expressions of phosphatidylinositol-3-kinases (PI3K), Akt, nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) of the aortae were determined. The data showed that CCC can significantly decrease the levels of blood lipids, atherosclerosis index, and plaque areas and increase collagen proportion in plaques as compared with the untreated mice (p < 0.05, p < 0.01). In addition, CCC can significantly reduce the mRNA expressions of PI3K, Akt, NF-κB, IL-6, and TNF-α in the mice fed with a high-fat diet (p < 0.001). Thus, we concluded that CCC can inhibit inflammatory reaction in the ApoE(-/-) mice fed with a high-fat diet. This mechanism may be attributed to regulating PI3K/Akt/NF-κB signaling pathway. PMID:26539229

  12. The neuroprotective action of pyrroloquinoline quinone against glutamate-induced apoptosis in hippocampal neurons is mediated through the activation of PI3K/Akt pathway

    SciTech Connect

    Zhang Qi; Shen Mi; Ding Mei; Shen Dingding; Ding Fei

    2011-04-01

    Pyrroloquinoline quinone (PQQ), a cofactor in several enzyme-catalyzed redox reactions, possesses a potential capability of scavenging reactive oxygen species (ROS) and inhibiting cell apoptosis. In this study, we investigated the effects of PQQ on glutamate-induced cell death in primary cultured hippocampal neurons and the possible underlying mechanisms. We found that glutamate-induced apoptosis in cultured hippocampal neurons was significantly attenuated by the ensuing PQQ treatment, which also inhibited the glutamate-induced increase in Ca2+ influx, caspase-3 activity, and ROS production, and reversed the glutamate-induced decrease in Bcl-2/Bax ratio. The examination of signaling pathways revealed that PQQ treatment activated the phosphorylation of Akt and suppressed the glutamate-induced phosphorylation of c-Jun N-terminal protein kinase (JNK). And inhibition of phosphatidylinositol-3-kinase (PI3K)/Akt cascade by LY294002 and wortmannin significantly blocked the protective effects of PQQ, and alleviated the increase in Bcl-2/Bax ratio. Taken together, our results indicated that PQQ could protect primary cultured hippocampal neurons against glutamate-induced cell damage by scavenging ROS, reducing Ca2+ influx, and caspase-3 activity, and suggested that PQQ-activated PI3K/Akt signaling might be responsible for its neuroprotective action through modulation of glutamate-induced imbalance between Bcl-2 and Bax. - Research Highlights: >PQQ attenuated glutamate-induced cell apoptosis of cultured hippocampal neurons. >PQQ inhibited glutamate-induced Ca{sup 2+} influx and caspase-3 activity. >PQQ reduced glutamate-induced increase in ROS production. >PQQ affected phosphorylation of Akt and JNK signalings after glutamate injury. >PI3K/Akt was required for neuroprotection of PQQ by modulating Bcl-2/Bax ratio.

  13. Effect of Compound Chuanxiong Capsule on Inflammatory Reaction and PI3K/Akt/NF-κB Signaling Pathway in Atherosclerosis

    PubMed Central

    Kang, Qunfu; Liu, Weihong; Liu, Hongxu; Zhou, Mingxue

    2015-01-01

    Compound Chuanxiong Capsule (CCC), a Chinese herbal compound, can exhibit antiatherosclerotic effect; however, its mechanism is still unclear. This study is designed to study the mechanism of CCC on atherosclerosis in the ApoE-knockout (ApoE−/−) mice fed with a high-fat diet. After 6 weeks of high-fat feeding, 40 ApoE−/− mice were randomized (n = 10) and treated with lipitor, high-dose or low-dose CCC, or distilled water (ApoE−/− group) for 7 weeks. The blood lipids in serum and the plaque areas of the mice were measured and the mRNA expressions of phosphatidylinositol-3-kinases (PI3K), Akt, nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) of the aortae were determined. The data showed that CCC can significantly decrease the levels of blood lipids, atherosclerosis index, and plaque areas and increase collagen proportion in plaques as compared with the untreated mice (p < 0.05, p < 0.01). In addition, CCC can significantly reduce the mRNA expressions of PI3K, Akt, NF-κB, IL-6, and TNF-α in the mice fed with a high-fat diet (p < 0.001). Thus, we concluded that CCC can inhibit inflammatory reaction in the ApoE−/− mice fed with a high-fat diet. This mechanism may be attributed to regulating PI3K/Akt/NF-κB signaling pathway. PMID:26539229

  14. Control of fibroblast fibronectin expression and alternative splicing via the PI3K/Akt/mTOR pathway

    SciTech Connect

    White, Eric S.; Sagana, Rommel L.; Booth, Adam J.; Yan, Mei; Cornett, Ashley M.; Bloomheart, Christopher A.; Tsui, Jessica L.; Wilke, Carol A.; Moore, Bethany B.; Ritzenthaler, Jeffrey D.; Roman, Jesse; Muro, Andres F.

    2010-10-01

    Fibronectin (FN), a ubiquitous glycoprotein that plays critical roles in physiologic and pathologic conditions, undergoes alternative splicing which distinguishes plasma FN (pFN) from cellular FN (cFN). Although both pFN and cFN can be incorporated into the extracellular matrix, a distinguishing feature of cFN is the inclusion of an alternatively spliced exon termed EDA (for extra type III domain A). The molecular steps involved in EDA splicing are well-characterized, but pathways influencing EDA splicing are less clear. We have previously found an obligate role for inhibition of the tumor suppressor phosphatase and tensin homologue on chromosome 10 (PTEN), the primary regulator of the PI3K/Akt pathway, in fibroblast activation. Here we show TGF-{beta}, a potent inducer of both EDA splicing and fibroblast activation, inhibits PTEN expression and activity in mesenchymal cells, corresponding with enhanced PI3K/Akt signaling. In pten{sup -/-} fibroblasts, which resemble activated fibroblasts, inhibition of Akt attenuated FN production and decreased EDA alternative splicing. Moreover, inhibition of mammalian target of rapamycin (mTOR) in pten{sup -/-} cells also blocked FN production and EDA splicing. This effect was due to inhibition of Akt-mediated phosphorylation of the primary EDA splicing regulatory protein SF2/ASF. Importantly, FN silencing in pten{sup -/-} cells resulted in attenuated proliferation and migration. Thus, our results demonstrate that the PI3K/Akt/mTOR axis is instrumental in FN transcription and alternative splicing, which regulates cell behavior.

  15. Biphasic activation of PI3K/Akt and MAPK/Erk1/2 signaling pathways in bovine herpesvirus type 1 infection of MDBK cells.

    PubMed

    Zhu, Liqian; Ding, Xiuyan; Zhu, Xiaofang; Meng, Songshu; Wang, Jianye; Zhou, Hong; Duan, Qiangde; Tao, Jie; Schifferli, Dieter M; Zhu, Guoqiang

    2011-04-14

    Many viruses have been known to control key cellular signaling pathways to facilitate the virus infection. The possible involvement of signaling pathways in bovine herpesvirus type 1 (BoHV-1) infection is unknown. This study indicated that infection of MDBK cells with BoHV-1 induced an early-stage transient and a late-stage sustained activation of both phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen activated protein kinases/extracellular signal-regulated kinase 1/2 (MAPK/Erk1/2) signaling pathways. Analysis with the stimulation of UV-irradiated virus indicated that the virus binding and/or entry process was enough to trigger the early phase activations, while the late phase activations were viral protein expression dependent. Biphasic activation of both pathways was suppressed by the selective inhibitor, Ly294002 for PI3K and U0126 for MAPK kinase (MEK1/2), respectively. Furthermore, treatment of MDBK cells with Ly294002 caused a 1.5-log reduction in virus titer, while U0126 had little effect on the virus production. In addition, the inhibition effect of Ly294002 mainly occurred at the post-entry stage of the virus replication cycle. This revealed for the first time that BoHV-1 actively induced both PI3K/Akt and MAPK/Erk1/2 signaling pathways, and the activation of PI3K was important for fully efficient replication, especially for the post-entry stage.

  16. The Regulation of Lipid Deposition by Insulin in Goose Liver Cells Is Mediated by the PI3K-AKT-mTOR Signaling Pathway

    PubMed Central

    Han, Chunchun; Wei, Shouhai; He, Fang; Liu, Dandan; Wan, Huofu; Liu, Hehe; Li, Liang; Xu, Hongyong; Du, Xiaohui; Xu, Feng

    2015-01-01

    Background We previously showed that the fatty liver formations observed in overfed geese are accompanied by the activation of the PI3K-Akt-mTOR pathway and an increase in plasma insulin concentrations. Recent studies have suggested a crucial role for the PI3K-Akt-mTOR pathway in regulating lipid metabolism; therefore, we hypothesized that insulin affects goose hepatocellular lipid metabolism through the PI3K-Akt-mTOR signaling pathway. Methods Goose primary hepatocytes were isolated and treated with serum-free media supplemented with PI3K-Akt-mTOR pathway inhibitors (LY294002, rapamycin, and NVP-BEZ235, respectively) and 50 or 150 nmol/L insulin. Results Insulin induced strong effects on lipid accumulation as well as the mRNA and protein levels of genes involved in lipogenesis, fatty acid oxidation, and VLDL-TG assembly and secretion in primary goose hepatocytes. The stimulatory effect of insulin on lipogenesis was significantly decreased by treatment with PI3K-Akt-mTOR inhibitors. These inhibitors also rescued the insulin-induced down-regulation of fatty acid oxidation and VLDL-TG assembly and secretion. Conclusion These findings suggest that the stimulatory effect of insulin on lipid deposition is mediated by PI3K-Akt-mTOR regulation of lipogenesis, fatty acid oxidation, and VLDL-TG assembly and secretion in goose hepatocytes. PMID:25945932

  17. MicroRNA-214 acts as a potential oncogene in breast cancer by targeting the PTEN-PI3K/Akt signaling pathway.

    PubMed

    Wang, Fang; Li, Lin; Chen, Zhuo; Zhu, Mingzhi; Gu, Yuanting

    2016-05-01

    Breast cancer ranks as the leading cause of cancer-related mortality in females worldwide. It has been proven that microRNAs (miRNAs or miRs), a type of non‑coding RNA, are involved in tumorigenesis. An increasing number of studies has confirmed the critical role of miR‑214 in certain types of cancer. Nevertheless, the biological function of miR‑214, as well as its underlying mechanisms of action in breast cancer remain largely unknown. In the present study, the expression of miR‑214 was found to be upregulated in four human breast cancer cell lines in contrast to its expression level in the non‑malignant breast epithelial cell line, MCF‑10A. Moreover, the overexpression of miR‑214 markedly increased cell viability and abrogated the apoptosis triggered by serum starvation, indicating that miR‑214 plays a pivotal role in breast cancer cell growth. Further analysis suggested that the upregulation of miR‑214 markedly induced the activation of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway, which largely accounted for the protective effects of miR‑124 on cancer cell growth. This was further confimed by pre‑treatment with the PI3K/Akt inhibitor, LY294002, which markedly attenuated the miR‑214‑induced increase in cell viability and resistance to apoptosis. Furthermore, the expression of phosphatase and tensin homolog (PTEN) was decreased following transfection wtih miR‑214 mimics and PTEN was confirmed as the direct target of miR‑214 by bioinformatics analysis and a dual‑firefly luciferase reporter assay. Importantly, the introduction of PTEN cDNA lacking the 3' untranslated region (3'UTR) significantly inhibited the miR‑214‑induced activation of the PI3K/Akt signaling pathway, and abrogated the protetive effects of miR‑214 on cell survival and resistance to apoptosis. Taken together, these findings suggest that miR‑214 possesses oncogenic activity and that its effects are mediated through the promotion of cell growth

  18. Gardenamide A Protects RGC-5 Cells from H₂O₂-Induced Oxidative Stress Insults by Activating PI3K/Akt/eNOS Signaling Pathway.

    PubMed

    Wang, Rikang; Peng, Lizhi; Zhao, Jiaqiang; Zhang, Laitao; Guo, Cuiping; Zheng, Wenhua; Chen, Heru

    2015-01-01

    Gardenamide A (GA) protects the rat retinal ganglion (RGC-5) cells against cell apoptosis induced by H₂O₂. The protective effect of GA was completely abrogated by the specific phosphoinositide 3-kinase (PI3K) inhibitor LY294002, and the specific protein kinase B (Akt) inhibitor Akt VIII respectively, indicating that the protective mechanism of GA is mediated by the PI3K/Akt signaling pathway. The specific extracellular signal-regulated kinase (ERK1/2) inhibitor PD98059 could not block the neuroprotection of GA. GA attenuated the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) induced by H₂O₂. Western blotting showed that GA promoted the phosphorylation of ERK1/2, Akt and endothelial nitric oxide synthase (eNOS), respectively, and effectively reversed the H₂O₂-inhibited phosphorylation of these three proteins. LY294002 completely inhibited the GA-activated phosphorylation of Akt, while only partially inhibiting eNOS. This evidence implies that eNOS may be activated directly by GA. PD98059 attenuated only partially the GA-induced phosphorylation of ERK1/2 with/without the presence of H₂O₂, indicating that GA may activate ERK1/2 directly. All these results put together confirm that GA protects RGC-5 cells from H₂O₂ insults via the activation of PI3K/Akt/eNOS signaling pathway. Whether the ERK1/2 signaling pathway is involved requires further investigations.

  19. Jolkinolide B induces apoptosis in MDA-MB-231 cells through inhibition of the PI3K/Akt signaling pathway.

    PubMed

    Lin, Yu; Cui, Hongxia; Xu, Huiyu; Yue, Liling; Xu, Hao; Jiang, Liyan; Liu, Jicheng

    2012-06-01

    The phosphoinositol-3-kinase (PI3K)/Akt signal transduction pathway is critically important for tumor cell growth, proliferation and apoptosis. Apoptosis activation has been reported to be a good target in cancer therapies. In this study, we have found that jolkinolide B (JB), a diterpenoid from the traditional Chinese medicinal herb Euphorbia fischeriana Steud, strongly inhibited the expression of the PI3K p85 subunit and the phosphorylation of Akt. Furthermore, we evaluated the effects of JB on the proliferation and apoptosis of MDA-MB-231 human breast cancer cells. Our results show significant induction of apoptosis in MDA-MB-231 cells incubated with JB. This effect was enhanced by combination with LY294002. In addition, treatment with JB could induce downregulation of the Bcl-2/Bax ratio, and subsequent promotion of mitochondrial release of cytochrome c and activation of caspase-3. Taken together, JB-induced apoptosis of MDA-MB-231 cells occurs through the mitochondrial pathway. Further, the PI3K/Akt signaling cascade plays a role in the induction of apoptosis in JB-treated cells. These observations suggest that JB may have therapeutic applications in the treatment of cancer.

  20. Interleukin-21 promotes osteoclastogenesis in RAW264.7 cells through the PI3K/AKT signaling pathway independently of RANKL.

    PubMed

    Xing, Rui; Zhang, Yingjian; Li, Changhong; Sun, Lin; Yang, Lin; Zhao, Jinxia; Liu, Xiangyuan

    2016-10-01

    Cytokines play a key role in the bone destruction of rheumatoid arthritis (RA). Interleukin-21 (IL-21) promotes osteoclastogenesis in RA in a receptor activator of nuclear factor-κB ligand (RANKL)-dependent way. Whether IL-21 is capable of promoting osteoclastogenesis directly in the absence of RANKL remains unknown. In the present study, we examined the osteoclastogenic activity of IL-21 in RAW264.7 cells in the absence of RANKL. We found that IL-21 enhanced osteoclastogenesis and this was demonstrated by increased numbers of tartrate-resistant acid phosphatase (TRAP)-positive stained, multinucleated cells compared with the negative control. Western blot analysis and immunocytochemistry showed the positive expression of calcitonin receptor (CTR) in the IL-21 group. RT-PCR and RT-qPCR also verified the increased mRNA expression of CTR and cathepsin K in the IL-21 group compared with the negative control. The scanning electronic microscope images showed a few resorption pits on the bone slices cultured with IL-21. The phosphoinositide 3-kinase (PI3K)/AKT pathway inhibitor LY294002 significantly suppressed IL-21-induced osteoclastogenesis. Taken together, these findings suggest that IL-21 has direct osteoclastogenic potential independently of RANKL. IL-21 may promote osteoclastogenesis through the PI3K/AKT signaling pathway. Therapy targeting IL-21 may be of value in preventing bone erosions in patients with RA. PMID:27599586

  1. Interleukin-21 promotes osteoclastogenesis in RAW264.7 cells through the PI3K/AKT signaling pathway independently of RANKL

    PubMed Central

    Xing, Rui; Zhang, Yingjian; Li, Changhong; Sun, Lin; Yang, Lin; Zhao, Jinxia; Liu, Xiangyuan

    2016-01-01

    Cytokines play a key role in the bone destruction of rheumatoid arthritis (RA). Interleukin-21 (IL-21) promotes osteoclastogenesis in RA in a receptor activator of nuclear factor-κB ligand (RANKL)-dependent way. Whether IL-21 is capable of promoting osteoclastogenesis directly in the absence of RANKL remains unknown. In the present study, we examined the osteoclastogenic activity of IL-21 in RAW264.7 cells in the absence of RANKL. We found that IL-21 enhanced osteoclastogenesis and this was demonstrated by increased numbers of tartrate-resistant acid phosphatase (TRAP)-positive stained, multinucleated cells compared with the negative control. Western blot analysis and immunocytochemistry showed the positive expression of calcitonin receptor (CTR) in the IL-21 group. RT-PCR and RT-qPCR also verified the increased mRNA expression of CTR and cathepsin K in the IL-21 group compared with the negative control. The scanning electronic microscope images showed a few resorption pits on the bone slices cultured with IL-21. The phosphoinositide 3-kinase (PI3K)/AKT pathway inhibitor LY294002 significantly suppressed IL-21-induced osteoclastogenesis. Taken together, these findings suggest that IL-21 has direct osteoclastogenic potential independently of RANKL. IL-21 may promote osteoclastogenesis through the PI3K/AKT signaling pathway. Therapy targeting IL-21 may be of value in preventing bone erosions in patients with RA. PMID:27599586

  2. Matrine Suppresses Proliferation and Invasion of SGC7901 Cells through Inactivation of PI3K/Akt/uPA Pathway.

    PubMed

    Peng, Xiaochun; Zhou, Dawei; Wang, Xianwang; Hu, Zhifan; Yan, Yan; Huang, Jiangrong

    2016-09-01

    This study was to examine the inhibitory effect of matrine on the proliferation and metastasis of gastric cancer cells, and to explore the possible mechanisms involved in these processes. MTT was used to evaluate the proliferation ability of SGC7901 cells. A two and three-dimensional cell migration assay were performed to determine the effect of matrine on the migration of SGC7901 cells. Then, the changes of the uPA protein and other possible signal molecules were detected by western blot. We found that the proliferation ability of SGC 7901 cells was suppressed by matrine (p<0.05), and the average cell migration velocity was also significantly inhibited by matrine when compared to the control in a two-dimensional cell migration assay. In addition, SGC7901cells treated with matrine (50μg/ml) migrated less than the control cells in a three-dimensional cell migration assay. At the meantime, the decreased uPA protein expression in SGC7901 cells treated with matrine was observed, and the PI3K/Akt pathway was inhibited. These results suggested that matrine can inhibit the proliferation and metastasis of gastric cancer cells through the PI3K/Akt/uPA pathway, indicating that matrine might be a potential molecular target for treatment of gastric carcinoma.

  3. Modulatory role of garlicin in migration and invasion of intrahepatic cholangiocarcinoma via PI3K/AKT pathway

    PubMed Central

    Xie, Kun; Nian, Jianze; Zhu, Xingyang; Geng, Xiaoping; Liu, Fubao

    2015-01-01

    Increasing evidences have indicated the role of garlicin in inhibiting the progression of various tumors including glioma, pulmonary carcinoma and pancreatic carcinoma, via mediating cell apoptosis or cell cycle. The regulatory effect and related molecular mechanism of garlicin in intrahepatic cholangiocarcinoma, however, remained unknown. This study thus aimed to investigate this scientific issue. HCCC-9810 cell line was treated with serially diluted garlicin, followed by cell proliferation assay using MTT approach. Transwell migration and invasion assays were further employed the regulatory effect of garlicin. The expression level of p-AKT and AKT proteins in tumor cells was quantified by Western blot. The growth of tumor cells was significantly inhibited by high concentration of garlicin (> 1.5 μM). Lower concentration of garlicin showed dose-dependent inhibition of tumor cell invasion and migration. After using specific agonist IGF-1 (50 ng/mL) of PI3K/AKT signaling pathway, such facilitating effects of garlicin were depressed (P < 0.05). Western blotting showed significantly decreased phosphorylation level of AKT after treated with gradient concentrations of garlicin, while leaving the total AKT protein level unchanged. Garlicin may inhibit the invasion and migration of intrahepatic cholangiocarcinoma cells via inhibiting PI3K/AKT signaling pathway. PMID:26823715

  4. Recent Syntheses of PI3K/Akt/mTOR Signaling Pathway Inhibitors

    PubMed Central

    2013-01-01

    This review focuses on the syntheses of PI3K/Akt/mTOR inhibitors that have been reported outside of the patent literature in the last 5 years but is largely centered on synthetic work reported in 2011 and 2012. While focused on syntheses of inhibitors, some information on in vitro and in vivo testing of compounds is also included. Many of these reported compounds are reversible, competitive adenosine triphosphate (ATP) binding inhibitors, so given the structural similarities of many of these compounds to the adenine core, this review presents recent work on inhibitors based on where the synthetic chemistry was started, i.e. inhibitor syntheses which started with purines/pyrimidines are followed by inhibitor syntheses which began with pyridines, pyrazines, azoles, and triazines then moves to inhibitors which bear no structural resemblance to adenine: liphagal, wortmannin and quercetin analogs. The review then finishes with a short section on recent syntheses of phosphotidyl inositol (PI) analogs since competitive PI binding inhibitors represent an alternative to the competitive ATP binding inhibitors which have received the most attention. PMID:23735831

  5. Flavonoids Extraction from Propolis Attenuates Pathological Cardiac Hypertrophy through PI3K/AKT Signaling Pathway

    PubMed Central

    Sun, Guang-wei; Qiu, Zhi-dong; Wang, Wei-nan; Sui, Xin

    2016-01-01

    Propolis, a traditional medicine, has been widely used for a thousand years as an anti-inflammatory and antioxidant drug. The flavonoid fraction is the main active component of propolis, which possesses a wide range of biological activities, including activities related to heart disease. However, the role of the flavonoids extraction from propolis (FP) in heart disease remains unknown. This study shows that FP could attenuate ISO-induced pathological cardiac hypertrophy (PCH) and heart failure in mice. The effect of the two fetal cardiac genes, atrial natriuretic factor (ANF) and β-myosin heavy chain (β-MHC), on PCH was reversed by FP. Echocardiography analysis revealed cardiac ventricular dilation and contractile dysfunction in ISO-treated mice. This finding is consistent with the increased heart weight and cardiac ANF protein levels, massive replacement fibrosis, and myocardial apoptosis. However, pretreatment of mice with FP could attenuate cardiac dysfunction and hypertrophy in vivo. Furthermore, the cardiac protection of FP was suppressed by the pan-PI3K inhibitor wortmannin. FP is a novel cardioprotective agent that can attenuate adverse cardiac dysfunction, hypertrophy, and associated disorder, such as fibrosis. The effects may be closely correlated with PI3K/AKT signaling. FP may be clinically used to inhibit PCH progression and heart failure. PMID:27213000

  6. Imp2 regulates GBM progression by activating IGF2/PI3K/Akt pathway

    PubMed Central

    Mu, Qingchun; Wang, Lijun; Yu, Fengbo; Gao, Haijun; Lei, Ting; Li, Peiwen; Liu, Pengfei; Zheng, Xu; Hu, Xitong; Chen, Yong; Jiang, Zhenfeng; Sayari, Arash J; Shen, Jia; Huang, Haiyan

    2015-01-01

    Glioblastomas multiforme (GBM) are the most frequently occurring malignant brain cancers. Treatment for GBM consists of surgical resection and subsequent adjuvant radiation therapy and chemotherapy. Despite this, GBM patient survival is limited to 12–15 months, and researchers are continually trying to develop improved therapy options. Insulin-like growth factor 2 mRNA-binding protein 2 (Imp2) is known to be upregulated in many cancers and is known to regulate the signaling activity of insulin-like growth factor 2 (IGF2). However, relatively little is known about its role in malignant development of GBM. In this study, we first found Imp2 is upregulated in GBM tissues by using clinical samples and public database search. Studies with loss and gain of Imp2 expression in in vitro GBM cell culture system demonstrated the role of Imp2 in promoting GBM cell proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT). Additionally, our results show that Imp2 regulates the activity of IGF2, which further activates PI3K/Akt signaling, thereby to promote GBM malignancy. Inhibition of Imp2 was also found to sensitize GBM to temozolomide treatment. These observations add to the current knowledge of GBM biology, and may prove useful in development of more effective GBM therapy. PMID:25719943

  7. Exercise improves the dilatation function of mesenteric arteries in postmyocardial infarction rats via a PI3K/Akt/eNOS pathway-mediated mechanism.

    PubMed

    Wang, Youhua; Wang, Shengpeng; Wier, W Gil; Zhang, Quanjiang; Jiang, Hongke; Li, Qiuxia; Chen, Shengfeng; Tian, Zhenjun; Li, Youyou; Yu, Xiaojiang; Zhao, Ming; Liu, Jinjun; Yang, Jing; Zhang, Jing; Zang, Weijin

    2010-12-01

    Myocardial infarction (MI) has been shown to induce endothelial dysfunction in peripheral resistance arteries and thus increase peripheral resistance. This study was designed to investigate the underlying mechanisms of post-MI-related dysfunctional dilatation of peripheral resistance arteries and, furthermore, to examine whether exercise may restore dysfunctional dilatation of peripheral resistance arteries. Adult male Sprague-Dawley rats were divided into three groups: sham-operated, MI, and MI + exercise. Ultrastructure and relaxation function of the mesenteric arteries, as well as phosphatidylinositol-3 kinase (PI3K), Akt kinases (Akt), endothelial nitric oxide synthase (eNOS) activity, and phosphorylation of PI3K, Akt, and eNOS by ACh were determined. Post-MI rats exhibited pronounced ultrastructural changes in mesenteric artery endothelial cells and endothelial dysfunction. In addition, the activities of PI3K, Akt, and eNOS, and their phosphorylation by ACh were significantly attenuated in mesenteric arteries (P < 0.05-0.01). After 8 wk of exercise, not only did endothelial cells appeared more normal in structure, but also ameliorated post-MI-associated mesenteric arterial dysfunction, which were accompanied by elevated activities of PI3K, Akt, and eNOS, and their phosphorylation by ACh (P < 0.05-0.01). Importantly, inhibition of either PI3K or eNOS attenuated exercise-induced restoration of the dilatation function and blocked PI3K, Akt, and eNOS phosphorylation by ACh in the mesenteric arteries. These data demonstrate that MI induces dysfunctional dilation of peripheral resistance arteries by degradation of endothelial structural integrity and attenuating PI3K-Akt-eNOS signaling. Exercise may restore dilatation function of peripheral resistance arteries by protecting endothelial structural integrity and increasing PI3K-Akt-eNOS signaling cascades.

  8. beta-Sitosterol induces G2/M arrest, endoreduplication, and apoptosis through the Bcl-2 and PI3K/Akt signaling pathways.

    PubMed

    Moon, Dong-Oh; Kim, Mun-Ock; Choi, Yung Hyun; Kim, Gi-Young

    2008-06-18

    beta-Sitosterol (SITO) is a potentially valuable candidate for cancer chemotherapy, however the cellular and molecular mechanisms responsible for its anti-cancer activity are unknown. Therefore, we attempted to elucidate the mechanisms responsible for SITO-induced anti-proliferation in human leukemia cells. Treatment with SITO increased caspase-3 activation and DNA fragmentation in U937 and HL60 cells. This effect was associated with significant G2/M arrest and endoreduplication. We also demonstrated that SITO treatment significantly increases levels of polymeric alpha-tubulin and promoted microtubule polymerization. We next elucidated that ectopic expression of Bcl-2 accelerates endoreduplication in U937 cells. Furthermore, the specific Bcl-2 inhibitor, HA14-1, prevented endoreduplication through G2 phase arrest. Interestingly, SITO treatment did not significantly promote endoreduplication or decrease cell viability in Bcl-2 null K562 cells. SITO treatment also induced a gradual increase of phosphatidyl-inositol 3-kinase (PI3K) and Akt phosphorylation. Treatment with the selective PI3K/Akt inhibitor LY29004 completely blocked endoreduplication and apoptosis in the presence of SITO. In addition, treatment with SITO-induced phosphorylation of extracellular signal-regulated protein kinase (ERK), however significance of ERK activation in the execution of apoptosis and endoreduplication is unknown. These results suggest that SITO induces endoreduplication by promoting spindle microtubule dynamics through the Bcl-2 and PI3K/Akt signaling pathways.

  9. Ketamine affects the neurogenesis of rat fetal neural stem progenitor cells via the PI3K/Akt-p27 signaling pathway

    PubMed Central

    Dong, Chaoxuan; Rovnaghi, Cynthia R.; Anand, KJS

    2014-01-01

    Ketamine is widely used as an anesthetic, analgesic, or sedative in pediatric patients. We reported that ketamine alters the normal neurogenesis of rat fetal neural stem progenitor cells (NSPCs) in the developing brain, but the underlying mechanisms remain unknown. The PI3K-PKB/Akt (Phosphatidylinositide 3-kinases/protein kinase B) signaling pathway plays many important roles in cell survival, apoptosis, and proliferation. We hypothesized that PI3K-PKB/Akt signaling may be involved in ketamine-altered neurogenesis of cultured NSPCs in vitro. NSPCs were isolated from Sprague-Dawley rat fetuses on gestational day 17. BrdU (bromodeoxyuridine) incorporation, Ki67 staining, and differentiation tests were utilized to identify primary cultured NSPCs. Immunofluorescent staining was used to detect Akt expression, whereas, Western blots measured phosphorylated Akt and p27 expression in NSPCs exposed to different treatments. We report that cultured NSPCs had properties of neurogenesis: proliferation and neural differentiation. PKB/Akt was expressed in cultured rat fetal cortical NSPCs. Ketamine inhibited the phosphorylation of Akt and further enhanced p27 expression in cultured NSPCs. All ketamine-induced PI3K/Akt signaling changes could be recovered by NMDA (N-Methyl-D-aspartate) receptor agonist, NMDA. These data suggest that inhibition of PI3K/Akt-p27 signaling may be involved in ketamine-induced neurotoxicity in the developing brain, whereas excitatory NMDA receptor activation may reverse these effects. PMID:25231110

  10. Induction of Autophagy and Apoptosis via PI3K/AKT/TOR Pathways by Azadirachtin A in Spodoptera litura Cells

    PubMed Central

    Shao, Xuehua; Lai, Duo; Zhang, Ling; Xu, Hanhong

    2016-01-01

    Azadirachtin is one of the most effective botanical insecticides and has been widely used in pest control. Toxicological reports show that azadirachtin can induce apoptosis in various insect cell lines. However, studies of azadirachtin-induced autophagy in cultured insect cells are lacking. This study reports that azadirachtin A significantly inhibits cell proliferation by inducing autophagic and apoptotic cell death in Spodoptera litura cultured cell line (SL-1 cell). Characteristic autophagolysosome and Atg8-PE (phosphatidylethanolamine) accumulation were observed by electron microscopy and western blotting, indicating that azadirachtin triggered autophagy in SL-1 cell. Furthermore, azadirachtin inhibited survival signaling by blocking the activation of PI3K, AKT and the down-stream target of rapamycin. Similar to the positive control of starvation, azadirachtin induced the activation of insulin receptor (InR) via a cellular feedback mechanism. In addition, the autophagy-related 5 (Atg5), a molecular switch of autophagy and apoptosis, was truncated (tAtg5) to trigger cytochrome c release into the cytoplasm under azadirachtin stress, which indicated that azadirachtin induced apoptosis through autophagy. Our findings suggest that azadirachtin primarily induced autophagy in SL-1 cell by dysregulating InR- and PI3K/AKT/TOR pathways, then stimulated apoptosis by activating tAtg5. PMID:27752103

  11. Nephroprotective Effects of Polydatin against Ischemia/Reperfusion Injury: A Role for the PI3K/Akt Signal Pathway

    PubMed Central

    Liu, Hong-Bao; Meng, Qiu-Hong; Huang, Chen; Wang, Jian-Bo; Liu, Xiao-Wei

    2015-01-01

    Oxidative stress and inflammation are involved in the pathogenesis in renal ischemia/reperfusion (I/R) injury. It has been demonstrated that polydatin processed the antioxidative, anti-inflammatory, and nephroprotective properties. However, whether it has beneficial effects and the possible mechanisms on renal I/R injury remain unclear. In our present study I/R models were simulated both in vitro and in vivo. Compared with vehicle control, the administration of polydatin significantly improved the renal function, accelerated the mitogenic response and reduced cell apoptosis in renal I/R injury models, strongly suppressed the I/R-induced upregulation of the expression of tumor necrosis factor-α, interleukin-1β, cyclooxygenase-2, inducible nitric oxide synthase, prostaglandin E-2, and nitric oxide levels, and dramatically decreased contents of malondialdehyde, but it increased the activity of superoxide dismutase, glutathione transferase, glutathione peroxidase and catalase, and the level of glutathione. Further investigation showed that polydatin upregulated the phosphorylation of Akt in kidneys of I/R injury dose-dependently. However, all beneficial effects of polydatin mentioned above were counteracted when we inhibited PI3K/Akt pathway with its specific inhibitor, wortmannin. Taken together, the present findings provide the first evidence demonstrating that PD exhibited prominent nephroprotective effects against renal I/R injury by antioxidative stress and inflammation through PI3-K/Akt-dependent molecular mechanisms. PMID:26576221

  12. IL-10 Protects Neurites in Oxygen-Glucose-Deprived Cortical Neurons through the PI3K/Akt Pathway

    PubMed Central

    Zhang, Yixian; Lin, Wei; Liu, Yong; Li, Tin; Zeng, Yongping; Chen, Jianhao; Du, Houwei; Chen, Ronghua; Tan, Yi; Liu, Nan

    2015-01-01

    IL-10, as a cytokine, has an anti-inflammatory cascade following various injuries, but it remains blurred whether IL-10 protects neurites of cortical neurons after oxygen-glucose deprivation injury. Here, we reported that IL-10, in a concentration-dependent manner, reduced neuronal apoptosis and increased neuronal survival in oxygen-glucose-deprived primary cortical neurons, producing an optimal protective effect at 20ng/ml. After staining NF-H and GAP-43, we found that IL-10 significantly protected neurites in terms of axon length and dendrite number by confocal microscopy. Furthermore, it induced the phosphorylation of AKT, suppressed the activation of caspase-3, and up-regulated the protein expression of GAP-43. In contrast, LY294002, a specific inhibitor of PI3K/AKT, reduced the level of AKT phosphorylation and GAP-43 expression, increased active caspase-3 expression and thus significantly weakened IL-10-mediated protective effect in the OGD-induced injury model. IL-10NA, the IL-10 neutralizing antibody, reduced the level of p-PI3K phosphorylation and increased the expression of active caspase-3. These findings suggest that IL-10 provides neuroprotective effects by protecting neurites through PI3K/AKT signaling pathway in oxygen-glucose-deprived primary cortical neurons. PMID:26366999

  13. Ferulic acid inhibits proliferation and promotes apoptosis via blockage of PI3K/Akt pathway in osteosarcoma cell.

    PubMed

    Wang, Ting; Gong, Xia; Jiang, Rong; Li, Hongzhong; Du, Weimin; Kuang, Ge

    2016-01-01

    Ferulic acid, a ubiquitous phenolic acid abundant in corn, wheat and flax, has potent anti-tumor effect in various cancer cell lines. However, the anti-tumor effect of ferulic acid on osteosarcoma remains unclear. Therefore, we conduct current study to examine the effect of ferulic acid on osteosarcoma cells and explore the underlying mechanisms. In present study, ferulic acid inhibited proliferation and induced apoptosis in both 143B and MG63 osteosarcoma cells dose-dependently, indicated by MTT assay and Annexin V-FITC apoptosis detection. Additionally, ferulic acid induced G0/G1 phase arrest and down-regulated the expression of cell cycle-related protein, CDK 2, CDK 4, CDK 6, confirmed by flow cytometry assay and western blotting. Moreover, ferulic acid upregulated Bax, downregulated Bcl-2, and subsequently enhanced caspase-3 activity. More importantly, ferulic acid dose-dependently inhibited PI3K/Akt activation. Using adenoviruses expressing active Akt, the anti-proliferation and pro-apoptosis of ferulic acid were reverted. Our results demonstrated that ferulic acid might inhibit proliferation and induce apoptosis via inhibiting PI3K/Akt pathway in osteosarcoma cells. Ferulic acid is a novel therapeutic agent for osteosarcoma. PMID:27158383

  14. TWEAK protects cardiomyocyte against apoptosis in a PI3K/AKT pathway dependent manner

    PubMed Central

    Yang, Bin; Yan, Ping; Gong, Hui; Zuo, Lin; Shi, Ying; Guo, Jian; Guo, Rui; Xie, Jun; Li, Bao

    2016-01-01

    Myocyte apoptosis is a key determinant of cardiac recovery and prognosis of patients with acute myocardial infarction (AMI). Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), a member of TNF superfamily, is a pro-inflammatory and pro-angiogenic cytokine implicated in physiological tissue regeneration and wound repair and is closely related to cardiac remodeling, dysfunction and fibrosis. However, the role of TWEAK and its receptor Fn14 in the cardiomyocyte apoptosis is still poorly understood. The present study aimed to investigate whether the TWEAK enhanced the cardiomyocyte apoptosis in AMI. The apoptosis of the cardiomyocyte cell line H9C2 was induced by hypoxia/reoxygenation. The apoptosis of H9C2 cells was evaluated by flow cytometry and caspase-3 activity assay under treatment with TWEAK at different concentrations. The phosphorylated signaling molecules and the expression involved in the surprising protection of TWEAK against the apoptosis with a dose-dependent manner (≥50 ng/ml). Furthermore, a rat myocardial ischemia and reperfusion (I/R) model was established by TWEAK preconditioning through injecting the TWEAK into the scar and border after ischemia immediately induced by ligating the left anterior descending coronary artery for 50 min and followed by different reperfusion times. The heart function was significantly improved in TWEAK preconditioning rats compared with controls as well as the infarct size was significantly reduced 21 days after reperfusion. Meanwhile, TWEAK protected the cardiac apoptosis by activation of cardioprotective signaling PI3K/AKT during I/R. Our findings suggest that TWEAK may represent a cardioprotective factor that inhibits the myocyte death of myocardial IRI. PMID:27725864

  15. Lycium barbarum Polysaccharides Protect against Trimethyltin Chloride-Induced Apoptosis via Sonic Hedgehog and PI3K/Akt Signaling Pathways in Mouse Neuro-2a Cells

    PubMed Central

    Zhao, Wanyun; Pan, Xiaoqi; Li, Tao; Zhang, Changchun; Shi, Nian

    2016-01-01

    Trimethyltin chloride (TMT) is a classic neurotoxicant that can cause severe neurodegenerative diseases. Some signaling pathways involving cell death play pivotal roles in the central nervous system. In this study, the role of Sonic Hedgehog (Shh) and PI3K/Akt pathways in TMT-induced apoptosis and protective effect of Lycium barbarum polysaccharides (LBP) on mouse neuro-2a (N2a) cells were investigated. Results showed that TMT treatment significantly enhanced apoptosis, upregulated proapoptotic Bax, downregulated antiapoptotic Bcl-2 expression, and increased caspase-3 activity in a dose-dependent manner in N2a cells. TMT induced oxidative stress in cells, performing reactive oxygen species (ROS) and malondialdehyde (MDA) excessive generation, and superoxide dismutase (SOD) activity reduction. TMT significantly decreased phosphorylated glycogen synthase kinase-3β (GSK-3β) and inhibited Shh and PI3K/Akt pathways. However, the addition of LBP upregulated GSK-3β phosphorylation, activated Shh and PI3K/Akt pathways, and eventually reduced apoptosis and oxidative stress caused by TMT. The interaction between Shh and PI3K/Akt pathways was clarified by specific PI3K inhibitor LY294002 or Shh inhibitor GDC-0449. Moreover, LY294002 and GDC-0449 pretreatment both induced phosphorylated GSK-3β downregulation and significantly promoted apoptosis induced by TMT. These results suggest that LBP could reduce TMT-induced N2a cells apoptosis by regulating GSK-3β phosphorylation, Shh, and PI3K/Akt signaling pathways. PMID:27143997

  16. Sphingosine-1-phosphate receptor 2 mediates endothelial cells dysfunction by PI3K-Akt pathway under high glucose condition.

    PubMed

    Liu, Weihua; Liu, Bin; Liu, Shaojun; Zhang, Jingzhi; Lin, Shuangfeng

    2016-04-01

    Endothelial dysfunction is believed the early stage of development of diabetic cardiovascular complications. Sphingosine-1-phosphate (S1P) regulates various biological activities by binding to sphingosine-1-phosphate receptors (S1PRs) including S1PR1-S1PR5. In the present study, the role of S1P receptors in S1P-induced human coronary artery endothelial cells (HCAECs) dysfunction under high glucose condition was investigated and the underlying mechanism was explored. S1PR1-S1PR5 mRNA levels were detected by quantitative Real-time PCR. NO level and polymorphonuclear neutrophils (PMN)-endothelial cells adhesion were measured by nitrate reductase and myeloperoxidase colorimetric method, respectively. Protein levels of endothelial nitric oxide synthase (eNOS), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1(ICAM-1), phosphatidylinositol 3-kinase (PI3K) and Akt were measured by Western blot analysis. S1PR2 were found the predominant S1P receptor expressed in HCAECs exposed to high glucose. NO level and eNOS activity were remarkably decreased, while PMN adhesion, VCAM-1 and ICAM-1 protein levels were increased significantly by S1P treatment in HCAECs exposed to high glucose and normal glucose. Blockage of S1PR2 with specific antagonist JTE-013 and small interfering RNA (siRNA) resulted in enhanced NO level and eNOS activity as well as decreased PMN adhesion, reduced protein levels of VCAM-1 and ICAM-1 induced by S1P. Furthermore, Phosphor-PI3K and phosphor-Akt level were markedly increased by S1PR2 blockade in S1P-treated cells exposed to high glucose, which were suppressed by PI3K inhibitor wortmannin. In conclusion, S1P/S1PR2 mediated endothelial dysfunction partly by inhibiting PI3K/Akt signaling pathway under high glucose condition. S1PR2 blockage could ameliorate endothelial dysfunction which might provide a potential therapeutic strategy for diabetic vascular complications. PMID:26921757

  17. TDRG1 functions in testicular seminoma are dependent on the PI3K/Akt/mTOR signaling pathway

    PubMed Central

    Wang, Yong; Gan, Yu; Tan, Zhengyu; Zhou, Jun; Kitazawa, Riko; Jiang, Xianzhen; Tang, Yuxin; Yang, Jianfu

    2016-01-01

    Human testis development-related gene 1 (TDRG1) is a recently identified gene that is expressed exclusively in the testes and promotes the development of testicular germ cell tumors. In this study, the role of TDRG1 in the development of testicular seminoma, which is the most common testicular germ cell tumor, was further investigated. Based on polymerase chain reaction, Western blotting, and immunohistochemistry tests, both gene and protein expression levels of TDRG1 were significantly upregulated in testicular seminoma tissues compared with normal testicular tissues. Additionally, the levels of phosphoinositide-3 kinase (PI3K)/p110 and Akt phosphorylation were dramatically upregulated in testicular seminoma tissues. Accordingly, in our cell experiment, seminoma TCam-2 cells were subjected to different treatments: the TDRG1 knockout, TDRG1 overexpression, PI3K inhibition (LY294002 administration), or PI3K activation (insulin-like growth factor-1 administration). Cell proliferation, the proliferation index, apoptosis rate, cell adhesive capacity, and cell invasion capability were assessed. Cells with both TDRG1 knockout and PI3K inhibition exhibited decreased cell proliferation, proliferation indexes, cell adhesion capacity, and cell invasion capability and increased apoptosis rates. Most of these effects were reversed by TDRG1 overexpression or PI3K activation, indicating that both TDRG1- and PI3K-mediated signaling promote proliferation and invasion of testicular seminoma cells. The knockout of TDRG1 significantly decreased the phosphorylation levels of PI3K/p85, PI3K/p110, Akt, and mammalian target of rapamycin (mTOR; Ser2448). Except for PI3K/p110, TDRG1 overexpression had the opposite effects on phosphorylation levels. Phosphorylated mTOR at Ser2481 and Thr2446 was not affected by TDRG1 or PI3K in our tests. Thus, these results indicate that TDRG1 promotes the development and migration of seminoma cells via the regulation of the PI3K/Akt/mTOR signaling pathway

  18. The PI3K/Akt Pathway Regulates Oxygen Metabolism via Pyruvate Dehydrogenase (PDH)-E1α Phosphorylation

    PubMed Central

    Cerniglia, George J.; Dey, Souvik; Gallagher-Colombo, Shannon M.; Daurio, Natalie A; Tuttle, Stephen; Busch, Theresa M.; Lin, Alexander; Sun, Ramon; Esipova, Tatiana V.; Vinogradov, Sergei A.; Denko, Nicholas; Koumenis, Constantinos; Maity, Amit

    2015-01-01

    Inhibition of the PI3K/Akt pathway decreases hypoxia within SQ20B human head and neck cancer xenografts. We set out to understand the molecular mechanism underlying this observation. We measured oxygen consumption using both a Clark electrode and an extracellular flux analyzer. We made these measurements after various pharmacologic and genetic manipulations. Pharmacologic inhibition of the PI3K/mTOR pathway or genetic inhibition of Akt/PI3K decreased the oxygen consumption rate (OCR) in vitro in SQ20B and other cell lines by 30–40%. Pharmacologic inhibition of this pathway increased phosphorylation of the E1α subunit of the pyruvate dehydrogenase (PDH) complex on Ser293, which inhibits activity of this critical gatekeeper of mitochondrial respiration. Expressing wild type PTEN in a doxycycline-inducible manner in a cell line with mutant PTEN led to an increase in PDH-E1α phosphorylation and a decrease in OCR. Pre-treatment of SQ20B cells with dichloroacetate (DCA), which inhibits PDH-E1α phosphorylation by inhibiting dehydrogenase kinases (PDKs), reversed the decrease in OCR in response to PI3K/Akt/mTOR inhibition. Likewise, introduction of exogenous PDH-E1α that contains serine to alanine mutations, which can no longer be regulated by phosphorylation, also blunted the decrease in OCR seen with PI3K/mTOR inhibition. Our findings highlight an association between the PI3K/mTOR pathway and tumor cell oxygen consumption that is regulated in part by PDH phosphorylation. These results have important implications for understanding the effects PI3K pathway activation in tumor metabolism and also in designing cancer therapy trials that use inhibitors of this pathway. PMID:25995437

  19. Status of PI3K/Akt/mTOR pathway inhibitors in lymphoma.

    PubMed

    Westin, Jason R

    2014-10-01

    The phosphatidylinositol-3-kinase (PI3K) pathway is well known to regulate a wide variety of essential cellular functions, including glucose metabolism, translational regulation of protein synthesis, cell proliferation, apoptosis, and survival. Aberrations in the PI3K pathway are among the most frequently observed in cancer, and include amplifications, rearrangements, mutations, and loss of regulators. As a net result of these anomalies, the PI3K pathway is activated in many malignancies, including in Hodgkin and non-Hodgkin lymphomas, and yields a competitive growth and survival advantage, increased metastatic ability, and resistance to conventional therapy. Numerous inhibitors targeting various nodes in the PI3K pathway are undergoing clinical development, and their current status in lymphoma will be the focus of this review.

  20. Momordin Ic induces HepG2 cell apoptosis through MAPK and PI3K/Akt-mediated mitochondrial pathways.

    PubMed

    Wang, Jing; Yuan, Li; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

    2013-06-01

    Momordin Ic is a natural triterpenoid saponin enriched in various Chinese and Japanese natural medicines such as the fruit of Kochia scoparia (L.) Schrad. So far, there is little scientific evidence for momordin Ic with regard to the anti-tumor activities. The aim of this work was to elucidate the anti-tumor effect of momordin Ic and the signal transduction pathways involved. We found that momordin Ic induced apoptosis in human hepatocellular carcinoma HepG2 cells, which were supported by DNA fragmentation, caspase-3 activation and PARP cleavage. Meanwhile, momordin Ic triggered reactive oxygen species (ROS) production together with collapse of mitochondrial membrane potential, cytochrome c release, down-regulation of Bcl-2 and up-regulation of Bax expression. The activation of p38 and JNK, inactivation of Erk1/2 and Akt were also demonstrated. Although ROS production rather than NO was stimulated, the expression of iNOS and HO-1 were altered after momordin Ic treatment for 4 h. Furthermore, the cytochrome c release, caspase-3 activation, Bax/Bcl-2 expression and PARP cleavage were promoted with LY294002 and U0126 intervention but were blocked by SB203580, SP600125, PI3K activator, NAC and 1,400 W pretreatment, demonstrating the mitochondrial disruption. Furthermore, momordin Ic combination with NAC influenced MAPK, PI3K/Akt and HO-1, iNOS pathways, MAPK and PI3K/Akt pathways also regulated the expression of HO-1 and iNOS. These results indicated that momordin Ic induced apoptosis through oxidative stress-regulated mitochondrial dysfunction involving the MAPK and PI3K-mediated iNOS and HO-1 pathways. Thus, momordin Ic might represent a potential source of anticancer candidate. PMID:23417763

  1. Cabazitaxel-induced autophagy via the PI3K/Akt/mTOR pathway contributes to A549 cell death.

    PubMed

    Huo, Ruichao; Wang, Lili; Liu, Peijuan; Zhao, Yong; Zhang, Caiqin; Bai, Bing; Liu, Xueying; Shi, Changhong; Wei, Sanhua; Zhang, Hai

    2016-10-01

    Cabazitaxel has been used to treat castration-resistant prostate cancer since its approval by the US Food and Drug Administration in 2010. However, whether cabazitaxel may inhibit the proliferation of other tissue‑derived cancer cells, and its underlying mechanism, remains unknown. In the present study, the A549 lung adenocarcinoma cancer cell line was exposed to cabazitaxel, in order to investigate its cytotoxic effect and determine the underlying mechanism. The results demonstrated that cabazitaxel was able to induce autophagy in A549 cells, as evidenced by the formation of autophagosomes, upregulated LC3‑II expression and increased LC3 puncta. Cabazitaxel‑induced autophagy had a cytotoxic effect on A549 cells, as evidenced by the induction of cell death and cell cycle arrest at G2/M phase, which was independent of the apoptotic pathway. Furthermore, transfection with Beclin1 small interfering RNA and treatment with the autophagy inhibitor 3‑methyladenine protected cells from cabazitaxel‑induced cell death, thus confirming that cabazitaxel‑induced autophagy contributed to A549 cell death. In addition, cabazitaxel targeted the phosphoinositide 3‑kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway to induce autophagy, as indicated by reduced phosphorylation of Akt and mTOR. In conclusion, the present study demonstrated that cabazitaxel exerts a cytotoxic effect on A549 cells by acting on the PI3K/Akt/mTOR pathway to promote autophagic cell death. This result supports the potential use of cabazitaxel as a chemotherapeutic agent for the treatment of lung cancer.

  2. PI3K/Akt pathway involving into apoptosis and invasion in human colon cancer cells LoVo.

    PubMed

    Jiang, Qun Guang; Li, Tai Yuan; Liu, Dong Ning; Zhang, Hai Tao

    2014-05-01

    In this study we determined the effects of Curcumin on human colon cancer cells line LoVo. We found that Curcumin significantly inhibited the proliferation, migration and invasion, and clone formation of LoVo cells in a dose-dependent manner. Curcumin also dose-dependently reduced the phosphorylation of proteins Akt and increased expression levels of the genes caspase-3, cytochrome-c, Bax mRNA in LoVo cells. In addition, Curcumin dose-dependently decreased gene Bcl-2 mRNA expression. Similar results were observed in LoVo cells treated with LY294002. These in vitro studies suggest that Curcumin may play its anti-cancer actions partly via suppressing PI3K/Akt signal pathway in LoVo cells.

  3. Role of TLR4-Mediated PI3K/AKT/GSK-3β Signaling Pathway in Apoptosis of Rat Hepatocytes

    PubMed Central

    Zhang, Xian; Jiang, Daorong; Jiang, Wei; Zhao, Min; Gan, Jianhe

    2015-01-01

    We investigated the mechanism of the Toll-like receptor 4- (TLR4-) mediated PI3K/AKT/GSK-3β signaling pathway in rat hepatocytes apoptosis induced by LPS. The cultured rat hepatocytes were treated with LPS alone or first pretreated with TLR4 inhibitor, AKT inhibitor, and GSK-3β inhibitor, respectively, and then stimulated with the same dose of LPS. Cell viability, cell apoptotic rate, and apoptosis morphology were assessed; the level of P-AKTSer473, P-GSK-3βSer9, and active Caspase-3 and the ratio of Bax/Bcl-2 were evaluated. The results indicated that cell viability decreased, while cell apoptotic rate increased with time after LPS stimulation. The expression of P-AKTSer473 and P-GSK-3βSer9 in the LPS group decreased compared with the control, while the level of active Caspase-3 and the ratio of Bax/Bcl-2 were significantly increased. These effects were attenuated by pretreatment with CLI-095. In addition, the apoptotic ratio decreased after pretreatment with LiCl but increased following pretreatment with LY294002. The expression of P-AKTSer473 further decreased following pretreatment with LY294002 and the expression of P-GSK-3βSer9 increased following pretreatment with LiCl. Moreover, pretreatment with CLI-095 weakened LPS-induced nuclear translocation of GSK-3β. Our findings suggest that the TLR4-mediated PI3K/AKT/GSK-3β signaling pathway is present in rat hepatocytes and participates in apoptosis of BRL-3A cells. PMID:26770978

  4. Curcumin Promotes Cell Cycle Arrest and Inhibits Survival of Human Renal Cancer Cells by Negative Modulation of the PI3K/AKT Signaling Pathway.

    PubMed

    Zhang, Hao; Xu, Weili; Li, Baolin; Zhang, Kai; Wu, Yudong; Xu, Haidong; Wang, Junyong; Zhang, Jun; Fan, Rui; Wei, Jinxing

    2015-12-01

    Curcumin possesses anti-cancer effects. In the current study, we tested the effect of curcumin on cell proliferation, viability, apoptosis, cell cycle phases, and activation of the PI3K/Akt pathway in the renal cell carcinoma (RCC) cell line RCC-949. We observed that cell proliferation and viability were markedly inhibited by curcumin, while cell apoptosis was promoted. The latter effect was associated with increased expression of Bcl-2 and diminished expression of Bax (both: mRNA and protein). The cells treated with curcumin increasingly went into cell cycle arrest, which was likely mediated by diminished expression of cyclin B1, as seen in curcumin-treated cells. In addition, curcumin decreased activation of the PI3K/AKT signaling pathway. In conclusion, our results demonstrate that curcumin exerts anti-cancer effects by negative modulation of the PI3K/AKT signaling pathway and may represent a promising new drug to treat RCC. PMID:27259310

  5. Knockdown of TACC3 inhibits trophoblast cell migration and invasion through the PI3K/Akt signaling pathway.

    PubMed

    Zhu, Xiaojun; Cao, Qianqian; Li, Xia; Wang, Zhengping

    2016-10-01

    The insufficient invasion of trophoblasts is known to be correlated with the development of preeclampsia. Transforming acidic coiled‑coil protein 3 (TACC3), a member of the TACC domain family, is important in the regulation of cell differentiation, migration and invasion. However, the role of TACC3 in trophoblast function during placental development remains to be fully elucidated. The present study aimed to determine the expression and function of TACC3 in human placenta and to examine the underlying mechanisms. TACC3 expression was analyzed in preeclamptic placentas using reverse transcription‑quantitative polymerase chain reaction and western blotting. Cell proliferation was determined by the MTT assay, and cell migration and invasion were measured using Transwell assays. The expression levels of TACC3, matrix metalloproteinase (MMP)‑2, MMP‑9, tissue inhibitor of metalloproteinase (TIMP)‑1, TIMP‑2, phosphoinositide 3‑kinase (PI3K), phosphorylated (p)‑PI3K, AKT and p‑AKT were detected by western blotting. The results showed that the expression of TACC3 was downregulated in preeclamptic placentas. The knockdown of TACC3 significantly inhibited HTR8/SVneo cell proliferation, migration and invasion, and inhibited the expression of matrix metalloproteinases. In addition, the knockdown of TACC3 significantly reduced the levels of p‑PI3K and Akt in the HTR8/SVneo cells. Taken together, the results of the present study demonstrated that the knockdown of TACC3 inhibited the migration and invasion of HTR8/SVneo cells through suppression of the PI3K/Akt signaling pathway. Therefore, TACC3 may serve as a novel potential target for treating preeclampsia. PMID:27572091

  6. Mutations in PI3K/AKT pathway genes and amplifications of PIK3CA are associated with patterns of recurrence in gastric cancers

    PubMed Central

    Fang, Wen-Liang; Huang, Kuo-Hung; Lan, Yuan-Tzu; Lin, Chien-Hsing; Chen, Ming-Huang; Chao, Yee; Lin, Wen-Chang; Lo, Su-Shun; Li, Anna Fen-Yau; Wu, Chew-Wun; Chiou, Shih-Hwa

    2016-01-01

    Mutations in genes involved in the PI3K/AKT pathway and amplifications of the PIK3CA gene in gastric cancer and their associations with clinicopathological characteristics and EBV infection were analyzed in this study. A total of 431 patients with gastric adenocarcinomas were enrolled, and 39 mutation hotspots were evaluated in these patients using MALDI-TOF mass spectrometry were analyzed. PIK3CA amplifications were analyzed using real-time quantitative PCR. Regarding patients with intestinal-type gastric cancer, those with mutations in PI3K/AKT pathway genes were also more likely to have tumors located in the lower-third of the stomach than were those without mutations. Regarding patients with diffuse-type gastric cancer, those with PI3K/AKT pathway mutations were more likely to have tumors located in the upper-third of the stomach and to have more hematogenous metastases, particularly in the liver and lungs, than were patients without such mutations (22.2% vs. 4.5%). No significant survival difference was observed between patients with vs. without PI3K/AKT pathway mutations. Mutations in PI3K/AKT pathway genes were associated with hematogenous metastasis in patients with diffuse-type gastric cancer. Only when the tumors were located in the middle-third of stomach, tumor with mutations of the PIK3CA gene or mutations of the PI3K/AKT pathway genes were associated with more EBV infection than those without mutations. Patients with PIK3CA amplifications were more likely to have diffuse-type and poorly differentiated gastric cancers and were more likely to experience peritoneal recurrence compared with those without PIK3CA amplifications. Even upon subgroup analysis, PI3KCA amplifications were found to not affect the patients’ outcomes. PMID:26701847

  7. Notoginsenoside R1 ameliorates podocyte injury in rats with diabetic nephropathy by activating the PI3K/Akt signaling pathway.

    PubMed

    Huang, Guodong; Lv, Jianzhen; Li, Tongyu; Huai, Guoli; Li, Xiang; Xiang, Shaowei; Wang, Longlong; Qin, Zhenlin; Pang, Jianli; Zou, Bingyu; Wang, Yi

    2016-10-01

    The present study was designed to examine the protective effect of notoginsenoside R1 (NR1) on podocytes in a rat model of streptozotocin (STZ)‑induced diabetic nephropathy (DN), and to explore the mechanism responsible for NR1-induced renal protection. Diabetes was induced by a single injection of STZ, and NR1 was administered daily at a dose of 5 mg/kg (low dose), 10 mg/kg (medium) and 20 mg/kg (high) for 16 weeks in Sprague-Dawley rats. Blood glucose levels, body weight and proteinuria were measured every 4 weeks, starting on the day that the rats received NR1. Furthermore, on the day of sacrifice, blood, urine and kidneys were collected in order to assess renal function according to general parameters. Pathological staining was performed to evaluate the renal protective effect of NR1, and the expression of the key slit diaphragm proteins, namely neprhin, podocin and desmin, were evaluated. In addition, the serum levels of inflammatory cytokines [tumor necrosis factor-α (TNF-α), tumor growth factor-β1 (TGF-β1), interleukin (IL)-1 and IL-6] as well as an anti-inflammatory cytokine (IL-10) were assessed, and the apoptosis of podocytes was quantified. Finally, the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway and the involvement of nuclear factor-κB (NF-κB) inactivation was further analyzed. In this study, NR1 improved renal function by ameliorating histological alterations, increasing the expression of nephrin and podocin, decreasing the expression of desmin, and inhibiting both the inflammatory response as well as the apoptosis of podocytes. Furthermore, NR1 treatment increased the phosphorylation of both PI3K (p85) and Akt, indicating that activation of the PI3K/Akt signaling pathway was involved. Moreover, NR1 treatment decreased the phosphorylation of NF-κB (p65), suggesting the downregulation of NF-κB. This is the first study to the best of our knowledge, to clearly demonstrate that NR1 treatment ameliorates podocyte injury

  8. Effects of dexmedetomidine postconditioning on myocardial ischemia and the role of the PI3K/Akt-dependent signaling pathway in reperfusion injury

    PubMed Central

    CHENG, XIANG YANG; GU, XIAO YU; GAO, QIN; ZONG, QIAO FENG; LI, XIAO HONG; ZHANG, YE

    2016-01-01

    The present study aimed to determine whether post-ischemic treatment with dexmedetomidine (DEX) protected the heart against acute myocardial ischemia/reperfusion (I/R)-induced injury in rats. The phosphatidylinositol-3 kinase/protein kinase B(PI3K/Akt)-dependent signaling pathway was also investigated. Male Sprague Dawley rats (n=64) were subjected to ligation of the left anterior descending artery (LAD), which produced ischemia for 25 min, followed by reperfusion. Following LAD ligation, rats were treated with DEX (5, 10 and 20 µg/kg) or underwent post-ischemic conditioning, which included three cycles of ischemic insult. In order to determine the role of the PI3K/Akt signaling pathway, wortmannin (Wort), a PI3K inhibitor, was used to treat a group of rats that had also been treated with DEX (20 µg/kg). Post-reperfusion, lactate dehydrogenase (LDH), cardiac troponin I (cTnI), creatine kinase isoenzymes (CK-MB), superoxide dismutase (SOD) and malondialdehyde (MDA) serum levels were measured using an ultraviolet spectrophotometer. The protein expression levels of phosphorylated (p)-Akt, Ser9-p-glycogen synthase kinase-3β (p-GSK-3β) and cleaved caspase-3 were detected in heart tissue by western blotting. The mRNA expression levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were detected using reverse transcription-polymerase chain reaction. At the end of the experiment, the hearts were removed and perfused in an isolated perfusion heart apparatus with Evans blue (1%) in order to determine the non-ischemic areas. The risk and infarct areas of the heart were not dyed. As expected, I/R induced myocardial infarction, as determined by the increased serum levels of cTnI, CK-MB and MDA, and the decreased levels of SOD. Post-ischemic treatment with DEX increased the expression levels of p-Akt and p-GSK-3β, whereas caspase-3 expression was reduced following DEX treatment compared with in the I/R group. Compared with the I/R group, the ratio of Bcl

  9. Notoginsenoside R1 ameliorates podocyte injury in rats with diabetic nephropathy by activating the PI3K/Akt signaling pathway

    PubMed Central

    Huang, Guodong; Lv, Jianzhen; Li, Tongyu; Huai, Guoli; Li, Xiang; Xiang, Shaowei; Wang, Longlong; Qin, Zhenlin; Pang, Jianli; Zou, Bingyu; Wang, Yi

    2016-01-01

    The present study was designed to examine the protective effect of notoginsenoside R1 (NR1) on podocytes in a rat model of streptozotocin (STZ)-induced diabetic nephropathy (DN), and to explore the mechanism responsible for NR1-induced renal protection. Diabetes was induced by a single injection of STZ, and NR1 was administered daily at a dose of 5 mg/kg (low dose), 10 mg/kg (medium) and 20 mg/kg (high) for 16 weeks in Sprague-Dawley rats. Blood glucose levels, body weight and proteinuria were measured every 4 weeks, starting on the day that the rats received NR1. Furthermore, on the day of sacrifice, blood, urine and kidneys were collected in order to assess renal function according to general parameters. Pathological staining was performed to evaluate the renal protective effect of NR1, and the expression of the key slit diaphragm proteins, namely neprhin, podocin and desmin, were evaluated. In addition, the serum levels of inflammatory cytokines [tumor necrosis factor-α (TNF-α), tumor growth factor-β1 (TGF-β1), interleukin (IL)-1 and IL-6] as well as an anti-inflammatory cytokine (IL-10) were assessed, and the apoptosis of podocytes was quantified. Finally, the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway and the involvement of nuclear factor-κB (NF-κB) inactivation was further analyzed. In this study, NR1 improved renal function by ameliorating histological alterations, increasing the expression of nephrin and podocin, decreasing the expression of desmin, and inhibiting both the inflammatory response as well as the apoptosis of podocytes. Furthermore, NR1 treatment increased the phosphorylation of both PI3K (p85) and Akt, indicating that activation of the PI3K/Akt signaling pathway was involved. Moreover, NR1 treatment decreased the phosphorylation of NF-κB (p65), suggesting the downregulation of NF-κB. This is the first study to the best of our knowledge, to clearly demonstrate that NR1 treatment ameliorates podocyte injury by inhibiting both

  10. γ-Enolase C-terminal peptide promotes cell survival and neurite outgrowth by activation of the PI3K/Akt and MAPK/ERK signalling pathways.

    PubMed

    Hafner, Anja; Obermajer, Nataša; Kos, Janko

    2012-04-15

    γ-Enolase, a glycolytic enzyme, is expressed specifically in neurons. It exerts neurotrophic activity and has been suggested to regulate growth, differentiation, survival and regeneration of neurons. In the present study, we investigated the involvement of γ-enolase in PI3K (phosphoinositide 3-kinase)/Akt and MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) signalling, the two pathways triggered predominantly by neurotrophic factors. Whereas the PI3K/Akt pathway, rather than the MAPK/ERK pathway, is involved in γ-enolase-enhanced cell survival, γ-enolase-stimulated neurite outgrowth requires both pathways, i.e. the activation of both PI3K and ERK1/2, leading to subsequent expression of the growth-cone-specific protein GAP-43 (growth-associated protein of 43 kDa). MEK (MAPK/ERK kinase) and PI3K inhibition blocked or attenuated the neurite outgrowth associated with dynamic remodelling of the actin-based cytoskeleton. We show that γ-enolase-mediated PI3K activation regulates RhoA kinase, a key regulator of actin cytoskeleton organization. Moreover, the inhibition of RhoA downstream effector ROCK (Rho-associated kinase) results in enhanced γ-enolase-induced neurite outgrowth, accompanied by actin polymerization and its redistribution to growth cones. Our results show that γ-enolase controls neuronal survival, differentiation and neurite regeneration by activating the PI3K/Akt and MAPK/ERK signalling pathways, resulting in downstream regulation of the molecular and cellular processes of cytoskeleton reorganization and cell remodelling, activation of transcriptional factors and regulation of the cell cycle.

  11. Cigarette sidestream smoke induces histone H3 phosphorylation via JNK and PI3K/Akt pathways, leading to the expression of proto-oncogenes.

    PubMed

    Ibuki, Yuko; Toyooka, Tatsushi; Zhao, Xiaoxu; Yoshida, Ikuma

    2014-06-01

    Post-translational modifications in histones have been associated with cancer. Although cigarette sidestream smoke (CSS) as well as mainstream smoke are carcinogens, the relationship between carcinogenicity and histone modifications has not yet been clarified. Here, we demonstrated that CSS induced phosphorylation of histones, involving a carcinogenic process. Treatment with CSS markedly induced the phosphorylation of histone H3 at serine 10 and 28 residues (H3S10 and H3S28), which was independent from the cell cycle, in the human pulmonary epithelial cell model, A549 and normal human lung fibroblasts, MRC-5 and WI-38. Using specific inhibitors and small interfering RNA, the phosphorylation of H3S10 was found to be mediated by c-jun N-terminal kinase (JNK) and phosphoinositide 3-kinase (PI3K)/Akt pathways. These pathways were different from that of the CSS-induced phosphorylation of histone H2AX (γ-H2AX) mediated by Ataxia telangiectasia-mutated (ATM) and ATM-Rad3-related (ATR) protein kinases. A chromatin immunoprecipitation assay revealed that the phosphorylation of H3S10 was increased in the promoter sites of the proto-oncogenes, c-fos and c-jun, which indicated that CSS plays a role in tumor promotion. Because the phosphorylation of H3S10 was decreased in the aldehyde-removed CSS and was significantly induced by treatment with formaldehyde, aldehydes are suspected to partially contribute to this phosphorylation. These findings suggested that any chemicals in CSS, including aldehydes, phosphorylate H3S10 via JNK and PI3K/Akt pathways, which is different from the DNA damage response, resulting in tumor promotion.

  12. Chinese herbal medicine formula tao hong si wu decoction protects against cerebral ischemia-reperfusion injury via PI3K/Akt and the Nrf2 signaling pathway.

    PubMed

    Li, Li; Yang, Na; Nin, Ling; Zhao, Zhilong; Chen, Lu; Yu, Jie; Jiang, Zhuyun; Zhong, Zhendong; Zeng, Daiwen; Qi, Hongyi; Xu, Xiaoyu

    2015-01-01

    The Chinese herbal medicine formula Tao Hong Si Wu decoction (THSWD) is traditionally used for the prevention and treatment of ischemic stroke. Transcription factor NF-E2-related factor 2 (Nrf2) regulates a battery of phase II enzymes and is known as the major mechanism of cellular defense against oxidative stress. The present study aimed to explore the potential effect of THSWD on the Nrf2 signaling pathway and the consequent effect during cerebral ischemia-reperfusion (I/R) injury. We found that THSWD reduced infarct volume and improved neurological function in a rat stroke model induced by middle cerebral artery occlusion (MCAO). Additionally, heme oxygenase 1 (HO-1), a key endogenous antioxidant enzyme regulated by Nrf2, was significantly further induced by THSWD in this in vivo model. In neuronal-like PC12 cells, THSWD remarkably up-regulated HO-1 expression and promoted Nrf2 nuclear translocation. Furthermore, phosphatidylinositol 3-kinase (PI3K)/Akt kinase was found to be involved in the upstream of Nrf2 regulation. In an in vitro oxygen-glucose deprivation/reperfusion (OGD-Rep) model, THSWD treatment significantly reduced cell death induced by OGD-Rep insult. Importantly, the protective action was attenuated while PI3K activity was inhibited by a specific inhibitor, LY294002, and the Nrf2 signaling pathway was blocked by antioxidant response element (ARE) decoy oligonucleotides. Collectively, these results demonstrated that THSWD exhibited notable neuroprotective properties in vitro and in vivo and activation of PI3K/Akt and the Nrf2 signaling pathway may be, at least in part, responsible for the protection. This study provides a better understanding of the molecular mechanism underlying the traditional use of the Chinese herbal medicine formula THSWD.

  13. Downregulation of PI3-K/Akt/PTEN pathway and activation of mitochondrial intrinsic apoptosis by Diclofenac and Curcumin in colon cancer.

    PubMed

    Rana, Chandan; Piplani, Honit; Vaish, Vivek; Nehru, Bimla; Sanyal, S N

    2015-04-01

    Phosphatidylinositol 3-kinase (PI3-K)/PTEN/Akt signaling is over activated in various tumors including colon cancer. Activation of this pathway regulates multiple biological processes such as apoptosis, metabolism, cell proliferation, and cell growth that underlie the biology of a cancer cell. In the present study, the chemopreventive effects have been observed of Diclofenac, a preferential COX-2 inhibitory non-steroidal anti-inflammatory drugs, and Curcumin, a natural anti-inflammatory agent, in the early stage of colorectal carcinogenesis induced by 1,2-dimethylhydrazine dihydrochloride in rats. The tumor-promoting role of PI3-K/Akt/PTEN signal transduction pathway and its association with anti-apoptotic family of proteins are also observed. Both Diclofenac and Curcumin downregulated the PI3-K and Akt expression while promoting the apoptotic mechanism. Diclofenac and Curcumin administration significantly increased the expression of pro-apoptotic Bcl-2 family members (Bad and Bax) while decreasing the anti-apoptotic Bcl-2 protein. An up-regulation of cysteine protease family apoptosis executioner, such as caspase-3 and -9, is seen. Diclofenac and Curcumin inhibited the Bcl-2 protein by directly interacting at the active site by multiple hydrogen bonding, as also evident by negative glide score of Bcl-2. These drugs stimulated apoptosis by increasing reactive oxygen species (ROS) generation and simultaneously decreasing the mitochondrial membrane potential (ΔΨ M). Diclofenac and Curcumin showed anti-neoplastic effects by downregulating PI3-K/Akt/PTEN pathway, inducing apoptosis, increasing ROS generation, and decreasing ΔΨ M. The anti-neoplastic and apoptotic effects were found enhanced when both Diclofenac and Curcumin were administered together, rather than individually.

  14. Regulation of the PI3-K/Akt survival pathway in the rat endometrium.

    PubMed

    Veillette, Annabelle; Grenier, Kathy; Brasseur, Kevin; Fréchette-Frigon, Guylaine; Leblanc, Valérie; Parent, Sophie; Asselin, Eric

    2013-03-01

    The occurrence of apoptosis and cell survival in the receptive uterus is intimately involved in the embryo implantation process in order to facilitate embryo attachment to the maternal endometrium. The initial stimulus leading to successful implantation might be triggered by the conceptus itself. By the end of rat embryo implantation, decidualization begins, followed by the regression of the decidua basalis on Day 14. The phosphatidylinositol 3-kinase (PI3-K) survival pathway and TGF-beta have been thought to play a role in this process. The objective of the present study was to investigate the regulation of the PI3-K/PTEN/Akt pathway in rat endometrium during pregnancy. Rats were killed on different days of pregnancy (Day 1-22 and postpartum) or pseudopregnancy (Day 1-9), and uteri were removed to collect endometrial tissues. The active form of Akt (pAkt) was increased at Day 5 of pregnancy and at Day 3 of pseudopregnancy as well as at Day 12 of pregnancy and at Day 1 postpartum. Of the three Akt isoforms (Akt1, Akt2, and Akt3), Akt3 was the only isoform phosphorylated at Day 5 during the implantation process and at postpartum as demonstrated by immunoprecipitation studies. PI3-K inhibition in vivo blocked Akt phosphorylation, reduced Smad2 phosphorylation, and reduced both TGF-beta2 and XIAP expression. PI3-K inhibition in cultured decidual cells led to inhibition of pAkt and decrease XIAP expression. These results suggest that Akt and XIAP may be important surviving signaling molecules by which apoptosis is regulated in the rat endometrium during pregnancy and that TGF-beta could be linked to this process.

  15. Curcumin inhibited HGF-induced EMT and angiogenesis through regulating c-Met dependent PI3K/Akt/mTOR signaling pathways in lung cancer.

    PubMed

    Jiao, Demin; Wang, Jian; Lu, Wei; Tang, Xiali; Chen, Jun; Mou, Hao; Chen, Qing-Yong

    2016-01-01

    The epithelial-mesenchymal transition (EMT) and angiogenesis have emerged as two pivotal events in cancer progression. Curcumin has been extensively studied in preclinical models and clinical trials of cancer prevention due to its favorable toxicity profile. However, the possible involvement of curcumin in the EMT and angiogenesis in lung cancer remains unclear. This study found that curcumin inhibited hepatocyte growth factor (HGF)-induced migration and EMT-related morphological changes in A549 and PC-9 cells. Moreover, pretreatment with curcumin blocked HGF-induced c-Met phosphorylation and downstream activation of Akt, mTOR, and S6. These effects mimicked that of c-Met inhibitor SU11274 or PI3 kinase inhibitor LY294002 or mTOR inhibitor rapamycin treatment. c-Met gene overexpression analysis further demonstrated that curcumin suppressed lung cancer cell EMT by inhibiting c-Met/Akt/mTOR signaling pathways. In human umbilical vein endothelial cells (HUVECs), we found that curcumin also significantly inhibited PI3K/Akt/mTOR signaling and induced apoptosis and reduced migration and tube formation of HGF-treated HUVEC. Finally, in the experimental mouse model, we showed that curcumin inhibited HGF-stimulated tumor growth and induced an increase in E-cadherin expression and a decrease in vimentin, CD34, and vascular endothelial growth factor (VEGF) expression. Collectively, these findings indicated that curcumin could inhibit HGF-promoted EMT and angiogenesis by targeting c-Met and blocking PI3K/Akt/mTOR pathways. PMID:27525306

  16. Ellagic acid protects endothelial cells from oxidized low-density lipoprotein-induced apoptosis by modulating the PI3K/Akt/eNOS pathway

    SciTech Connect

    Ou, Hsiu-Chung; Lee, Wen-Jane; Lee, Shin-Da; Huang, Chih-Yang; Chiu, Tsan-Hung; Tsai, Kun-Ling; Hsu, Wen-Cheng; Sheu, Wayne Huey-Herng

    2010-10-15

    Endothelial apoptosis is a driving force in atherosclerosis development. Oxidized low-density lipoprotein (oxLDL) promotes inflammatory and thrombotic processes and is highly atherogenic, as it stimulates macrophage cholesterol accumulation and foam cell formation. Previous studies have shown that the phosphatidylinositol 3-kinase/Akt/endothelial nitric oxide synthase/nitric oxide (PI3K/Akt/eNOS/NO) pathway is involved in oxLDL-induced endothelial apoptosis. Ellagic acid, a natural polyphenol found in berries and nuts, has in recent years been the subject of intense research within the fields of cancer and inflammation. However, its protective effects against oxLDL-induced injury in vascular endothelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effect of ellagic acid in human umbilical vein endothelial cells (HUVECs) exposed to oxLDL and explored the possible mechanisms. Our results showed that pretreatment with ellagic acid (5-20 {mu}M) significantly attenuated oxLDL-induced cytotoxicity, apoptotic features, and generation of reactive oxygen species (ROS). In addition, the anti-apoptotic effect of ellagic acid was partially inhibited by a PI3K inhibitor (wortmannin) and a specific eNOS inhibitor (cavtratin) but not by an ERK inhibitor (PD98059). In exploring the underlying mechanisms of ellagic acid action, we found that oxLDL decreased Akt and eNOS phosphorylation, which in turn activated NF-{kappa}B and downstream pro-apoptotic signaling events including calcium accumulation, destabilization of mitochondrial permeability, and disruption of the balance between pro- and anti-apoptotic Bcl-2 proteins. Those alterations induced by oxLDL, however, were attenuated by pretreatment with ellagic acid. The inhibition of oxLDL-induced endothelial apoptosis by ellagic acid is due at least in part to its anti-oxidant activity and its ability to modulate the PI3K/Akt/eNOS signaling pathway.

  17. Curcumin inhibited HGF-induced EMT and angiogenesis through regulating c-Met dependent PI3K/Akt/mTOR signaling pathways in lung cancer

    PubMed Central

    Jiao, Demin; Wang, Jian; Lu, Wei; Tang, Xiali; Chen, Jun; Mou, Hao; Chen, Qing-yong

    2016-01-01

    The epithelial-mesenchymal transition (EMT) and angiogenesis have emerged as two pivotal events in cancer progression. Curcumin has been extensively studied in preclinical models and clinical trials of cancer prevention due to its favorable toxicity profile. However, the possible involvement of curcumin in the EMT and angiogenesis in lung cancer remains unclear. This study found that curcumin inhibited hepatocyte growth factor (HGF)-induced migration and EMT-related morphological changes in A549 and PC-9 cells. Moreover, pretreatment with curcumin blocked HGF-induced c-Met phosphorylation and downstream activation of Akt, mTOR, and S6. These effects mimicked that of c-Met inhibitor SU11274 or PI3 kinase inhibitor LY294002 or mTOR inhibitor rapamycin treatment. c-Met gene overexpression analysis further demonstrated that curcumin suppressed lung cancer cell EMT by inhibiting c-Met/Akt/mTOR signaling pathways. In human umbilical vein endothelial cells (HUVECs), we found that curcumin also significantly inhibited PI3K/Akt/mTOR signaling and induced apoptosis and reduced migration and tube formation of HGF-treated HUVEC. Finally, in the experimental mouse model, we showed that curcumin inhibited HGF-stimulated tumor growth and induced an increase in E-cadherin expression and a decrease in vimentin, CD34, and vascular endothelial growth factor (VEGF) expression. Collectively, these findings indicated that curcumin could inhibit HGF-promoted EMT and angiogenesis by targeting c-Met and blocking PI3K/Akt/mTOR pathways. PMID:27525306

  18. Quantitative Proteomics Reveals that miR-155 Regulates the PI3K-AKT Pathway in Diffuse Large B-Cell Lymphoma

    PubMed Central

    Huang, Xin; Shen, Yulei; Liu, Miao; Bi, Chengfeng; Jiang, Chunsun; Iqbal, Javeed; McKeithan, Timothy W.; Chan, Wing C.; Ding, Shi-Jian; Fu, Kai

    2013-01-01

    The aberrant expression of microRNA-155 (miR-155), which has emerged as having a significant impact on the biological characteristics of lymphocytes, plays important roles in B-cell malignancies, such as diffuse large B-cell lymphoma (DLBCL). DLBCL is the most common non–Hodgkin's lymphoma in the adult population, accounting for approximately 40% of newly diagnosed non–Hodgkin's lymphoma cases globally. To determine the specific function of miR-155, a quantitative proteomics approach was applied to examine the inhibitory effects of miR-155 on protein synthesis in DLBCL cells. PIK3R1 (p85α), a negative regulator of the phosphatidylinositol 3-kinase (PI3K)–AKT pathway, was identified as a direct target of miR-155. A luciferase reporter was repressed through the direct interaction of miR-155 and the p85α 3′-untranslated region, and overexpression of miR-155 down-regulated both the transcription and translation of p85α. The PI3K-AKT signaling pathway was highly activated by the sustained overexpression of miR-155 in DHL16 cells, whereas knockdown of miR-155 in OCI-Ly3 cells diminished AKT activity. Taken together, our results reveal a novel target involved in miR-155 biological characteristics and provide a molecular link between the overexpression of miR-155 and the activation of PI3K-AKT in DLBCL. PMID:22609116

  19. De novo somatic mutations in components of the PI3K-AKT3-mTOR pathway cause hemimegalencephaly

    PubMed Central

    Lee, Jeong Ho; Huynh, My; Silhavy, Jennifer L; Kim, Sangwoo; Dixon-Salazar, Tracy; Heiberg, Andrew; Scott, Eric; Bafna, Vineet; Hill, Kiley J; Collazo, Adrienne; Funari, Vincent; Russ, Carsten; Gabriel, Stacey B; Mathern, Gary W; Gleeson, Joseph G

    2015-01-01

    De novo somatic mutations in focal areas are well documented in diseases such as neoplasia but are rarely reported in malformation of the developing brain. Hemimegalencephaly (HME) is characterized by overgrowth of either one of the two cerebral hemispheres. The molecular etiology of HME remains a mystery. The intractable epilepsy that is associated with HME can be relieved by the surgical treatment hemispherectomy, allowing sampling of diseased tissue. Exome sequencing and mass spectrometry analysis in paired brain-blood samples from individuals with HME (n = 20 cases) identified de novo somatic mutations in 30% of affected individuals in the PIK3CA, AKT3 and MTOR genes. A recurrent PIK3CA c.1633G>A mutation was found in four separate cases. Identified mutations were present in 8–40% of sequenced alleles in various brain regions and were associated with increased neuronal S6 protein phosphorylation in the brains of affected individuals, indicating aberrant activation of mammalian target of rapamycin (mTOR) signaling. Thus HME is probably a genetically mosaic disease caused by gain of function in phosphatidylinositol 3-kinase (PI3K)-AKT3-mTOR signaling. PMID:22729223

  20. 2,2',4,4'-Tetrabromodiphenyl ether promotes human neuroblastoma SH-SY5Y cells migration via the GPER/PI3K/Akt signal pathway.

    PubMed

    Tian, P-C; Wang, H-L; Chen, G-H; Luo, Q; Chen, Z; Wang, Y; Liu, Y-F

    2016-02-01

    Neuroblastoma is the predominant tumor of early childhood. 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) has the highest concentration among all polybrominated diphenyl ether (PBDE) congeners in human body, particularly for children. Considering that accumulating evidences showed developmental neurotoxicity of PBDE, there is an urgent need to investigate the effects of BDE-47 on the development of neuroblastoma. This study revealed that BDE-47 had limited effects on the cytotoxicity while significantly increased the in vitro migration and invasion of human neuroblastoma SH-SY5Y cells. This was further confirmed by the results that BDE-47 treatment significantly downregulated the expression of E-cadherin and zona occludin-1 and upregulated the expression of matrix metalloproteinase-9 (MMP-9). Silencing of MMP-9 by specific small interfering RNA significantly abolished the BDE-47-induced migration and invasion of SH-SY5Y cells. Further, the signals G protein-coupled estrogen receptor 1 (GPER)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (Akt) mediated the BDE-47-induced upregulation of MMP-9 and in vitro migration of SH-SY5Y cells since G15 (GPER inhibitor) and LY 294002 (PI3K/Akt inhibitor) significantly abolished the effects of BDE-47. Our results revealed that BDE-47 significantly triggered the metastasis of human neuroblastoma SH-SY5Y cells via upregulation of MMP-9 by the GPER/PI3K/Akt signal pathway. This study revealed for the first time that BDE-47 can promote the migration of SH-SY5Y cells. It also provided a better understanding about the metastasis of human neuroblastoma induced by environmental endocrine disruptors.

  1. Psoralidin inhibits proliferation and enhances apoptosis of human esophageal carcinoma cells via NF-κB and PI3K/Akt signaling pathways

    PubMed Central

    Jin, Zhiliang; Yan, Wei; Jin, Hui; Ge, Changzheng; Xu, Yanhua

    2016-01-01

    Esophageal cancer is the most common gastrointestinal cancer. Psoralidin exhibits antioxidant, anti-apoptotic, anti-inflammatory and antitumor effects, which result in the inhibition of cancer formation. The present study aimed to investigate the effect of psoralidin on esophageal carcinoma proliferation and growth, and to elucidate its underlying mechanism of action. The effect of psoralidin on cell proliferation was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Using an annexin V-fluorescein isothiocyanate/propidium iodide apoptosis detection kit and 4′,6-diamidino-2-phenylindole staining assay, the present study demonstrated that psoralidin significantly enhanced apoptosis of human esophageal carcinoma Eca9706 cells. In addition, caspase-3 activity was analyzed with a caspase-3 colorimetric assay kit, while nuclear factor (NF)-κB activity and protein phosphatidylinositol 3-kinase (PI3K)/Akt expression were measured with an NF-κB enzyme-linked immunosorbent assay kit and western blot analysis, respectively. Eca9706 cells were treated with a PI3K agonist in order to investigate the mechanism of action of psoralidin. It was observed that psoralidin was able to decrease the proliferation and promote the cellular apoptosis of Eca9706 cells in a dose-dependent manner. Furthermore, psoralidin was also able to inhibit the caspase-3 activity of Eca9706 cells in a dose-dependent manner. In addition, psoralidin inhibited NF-κB activity and reduced PI3K and Akt protein expression in Eca9706 cells. Notably, the PI3K agonist was able to reverse the effect of psoralidin on Eca9706 cells. The results of the present study demonstrated that psoralidin was able to inhibit proliferation and enhance apoptosis of human esophageal carcinoma cells via the NF-κB and PI3K/Akt signaling pathways. PMID:27446379

  2. Apoptosis Induction of Human Prostate Carcinoma DU145 Cells by Diallyl Disulfide via Modulation of JNK and PI3K/AKT Signaling Pathways

    PubMed Central

    Shin, Dong Yeok; Kim, Gi-Young; Lee, Jun Hyuk; Choi, Byung Tae; Yoo, Young Hyun; Choi, Yung Hyun

    2012-01-01

    Diallyl disulfide (DADS), a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound’s anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP) family proteins, depolarization of the mitochondrial membrane potential (MMP, ΔΨm) and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4) and Fas ligand (FasL) proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs), including extracellular-signal regulating kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK). A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059) and p38 MAPK (SB203580) had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells. PMID:23203057

  3. Coactivation of the PI3K/Akt and ERK signaling pathways in PCB153-induced NF-κB activation and caspase inhibition

    SciTech Connect

    Liu, Changjiang; Yang, Jixin; Fu, Wenjuan; Qi, Suqin; Wang, Chenmin; Quan, Chao; Yang, Kedi

    2014-06-15

    Polychlorinated biphenyls (PCBs) are a group of persistent and widely distributed environmental pollutants that have various deleterious effects, e.g., neurotoxicity, endocrine disruption and reproductive abnormalities. In order to verify the hypothesis that the PI3K/Akt and MAPK pathways play important roles in hepatotoxicity induced by PCBs, Sprague–Dawley (SD) rats were dosed with PCB153 intraperitoneally at 0, 4, 16 and 32 mg/kg for five consecutive days; BRL cells (rat liver cell line) were treated with PCB153 (0, 1, 5, and 10 μM) for 24 h. Results indicated that the PI3K/Akt and ERK pathways were activated in vivo and in vitro after exposure to PCB153, and protein levels of phospho-Akt and phospho-ERK were significantly increased. Nuclear factor-κB (NF-κB) activation and caspase-3, -8 and -9 inhibition caused by PCB153 were also observed. Inhibiting the ERK pathway significantly attenuated PCB153-induced NF-κB activation, whereas inhibiting the PI3K/Akt pathway hardly influenced phospho-NF-κB level. However, inhibiting the PI3K/Akt pathway significantly elevated caspase-3, -8 and -9 activities, while the ERK pathway only synergistically regulated caspase-9. Proliferating cell nuclear antigen (PCNA), a reliable indicator of cell proliferation, was also induced. Moreover, PCB153 led to hepatocellular hypertrophy and elevated liver weight. Taken together, PCB153 leads to aberrant proliferation and apoptosis of hepatocytes through NF-κB activation and caspase inhibition, and coactivated PI3K/Akt and ERK pathways play critical roles in PCB153-induced hepatotoxicity. - Highlights: • PCB153 led to hepatotoxicity through NF-κB activation and caspase inhibition. • The PI3K/Akt and ERK pathways were coactivated in vivo and in vitro by PCB153. • The ERK pathway regulated levels of phospho-NF-κB and caspase-9. • The PI3K/Akt pathway regulated levels of caspase-3, -8 and -9.

  4. Puerarin protects rat kidney from lead-induced apoptosis by modulating the PI3K/Akt/eNOS pathway

    SciTech Connect

    Liu, Chan-Min; Ma, Jie-Qiong; Sun, Yun-Zhi

    2012-02-01

    Puerarin (PU), a natural flavonoid, has been reported to have many benefits and medicinal properties. However, its protective effects against lead (Pb) induced injury in kidney have not been clarified. The aim of the present study was to investigate the effects of puerarin on renal oxidative stress and apoptosis in rats exposed to Pb. Wistar rats were exposed to lead acetate in the drinking water (500 mg Pb/l) with or without puerarin co-administration (100, 200, 300 and 400 mg PU/kg intragastrically once daily) for 75 days. Our data showed that puerarin significantly prevented Pb-induced nephrotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of kidney damage (serum urea, uric acid and creatinine) and histopathological analysis. Moreover, Pb-induced profound elevation of reactive oxygen species (ROS) production and oxidative stress, as evidenced by increasing of lipid peroxidation level and depleting of intracellular reduced glutathione (GSH) level in kidney, were suppressed by treatment with puerarin. Furthermore, TUNEL assay showed that Pb-induced apoptosis in rat kidney was significantly inhibited by puerarin. In exploring the underlying mechanisms of puerarin action, we found that activities of caspase-3 were markedly inhibited by the treatment of puerarin in the kidney of Pb-treated rats. Puerarin increased phosphorylated Akt, phosphorylated eNOS and NO levels in kidney, which in turn inactivated pro-apoptotic signaling events including inhibition of mitochondria cytochrome c release and restoration of the balance between pro- and anti-apoptotic Bcl-2 proteins in kidney of Pb-treated rats. In conclusion, these results suggested that the inhibition of Pb-induced apoptosis by puerarin is due at least in part to its antioxidant activity and its ability to modulate the PI3K/Akt/eNOS signaling pathway. Highlights: ► Puerarin prevented lead-induced nephrototoxicity. ► Puerarin reduced lead-induced increase in ROS and TBARS production

  5. Pramipexole-Induced Hypothermia Reduces Early Brain Injury via PI3K/AKT/GSK3β pathway in Subarachnoid Hemorrhage rats.

    PubMed

    Ma, Junwei; Wang, Zhong; Liu, Chenglin; Shen, Haitao; Chen, Zhouqing; Yin, Jia; Zuo, Gang; Duan, Xiaochun; Li, Haiying; Chen, Gang

    2016-01-01

    Previous studies have shown neuroprotective effects of hypothermia. However, its effects on subarachnoid hemorrhage (SAH)-induced early brain injury (EBI) remain unclear. In this study, a SAH rat model was employed to study the effects and mechanisms of pramipexole-induced hypothermia on EBI after SAH. Dose-response experiments were performed to select the appropriate pramipexole concentration and frequency of administration for induction of mild hypothermia (33-36 °C). Western blot, neurobehavioral evaluation, Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Fluoro-Jade B (FJB) staining were used to detect the effects of pramipexole-induced hypothermia on SAH-induced EBI, as well as to study whether controlled rewarming could attenuate these effects. Inhibitors targeting the PI3K/AKT/GSK3β pathway were administered to determine whether the neuroprotective effect of pramipexole-induced hypothermia was mediated by PI3K/AKT/GSK3β signaling pathway. The results showed that intraperitoneal injection of pramipexole at 0.25 body weight once per 8 hours was found to successfully and safely maintain rats at mild hypothermia. Pramipexole-induced hypothermia ameliorated SAH-induced brain cell death, blood-brain barrier damage and neurobehavioral deficits in a PI3K/AKT/GSK3β signaling-dependent manner. Therefore, we may conclude that pramipexole-induced hypothermia could effectively inhibit EBI after SAH in rats via PI3K/AKT/GSK3β signaling pathway. PMID:27026509

  6. Hypoactivity Affects IGF-1 Level and PI3K/AKT Signaling Pathway in Cerebral Structures Implied in Motor Control

    PubMed Central

    Mysoet, Julien; Canu, Marie-Hélène; Cieniewski-Bernard, Caroline; Bastide, Bruno; Dupont, Erwan

    2014-01-01

    A chronic reduction in neuromuscular activity through prolonged body immobilization in human alters motor task performance through a combination of peripheral and central factors. Studies performed in a rat model of sensorimotor restriction have shown functional and biochemical changes in sensorimotor cortex. However, the underlying mechanisms are still unclear. Interest was turned towards a possible implication of Insulin-like Growth Factor 1 (IGF-1), a growth factor known to mediate neuronal excitability and synaptic plasticity by inducing phosphorylation cascades which include the PI3K–AKT pathway. In order to better understand the influence of IGF-1 in cortical plasticity in rats submitted to a sensorimotor restriction, we analyzed the effect of hindlimb unloading on IGF-1 and its main molecular pathway in structures implied in motor control (sensorimotor cortex, striatum, cerebellum). IGF-1 level was determined by ELISA, and phosphorylation of its receptor and proteins of the PI3K–AKT pathway by immunoblot. In the sensorimotor cortex, our results indicate that HU induces a decrease in IGF-1 level; this alteration is associated to a decrease in activation of PI3K-AKT pathway. The same effect was observed in the striatum, although to a lower extent. No variation was noticed in the cerebellum. These results suggest that IGF-1 might contribute to cortical and striatal plasticity induced by a chronic sensorimotor restriction. PMID:25226394

  7. Involvement of PI3K/Akt/FoxO3a and PKA/CREB Signaling Pathways in the Protective Effect of Fluoxetine Against Corticosterone-Induced Cytotoxicity in PC12 Cells.

    PubMed

    Zeng, Bingqing; Li, Yiwen; Niu, Bo; Wang, Xinyi; Cheng, Yufang; Zhou, Zhongzhen; You, Tingting; Liu, Yonggang; Wang, Haitao; Xu, Jiangping

    2016-08-01

    The selective serotonin reuptake inhibitor fluoxetine is neuroprotective in several brain injury models. It is commonly used to treat major depressive disorder and related conditions, but its mechanism of action remains incompletely understood. Activation of the phosphatidylinositol-3-kinase/protein kinase B/forkhead box O3a (PI3K/Akt/FoxO3a) and protein kinase A/cAMP-response element binding protein (PKA/CREB) signaling pathways has been strongly implicated in the pathogenesis of depression and might be the downstream target of fluoxetine. Here, we used PC12 cells exposed to corticosterone (CORT) to study the neuroprotective effects of fluoxetine and the involvement of the PI3K/Akt/FoxO3a and PKA/CREB signaling pathways. Our results show that CORT reduced PC12 cells viability by 70 %, and that fluoxetine showed a concentration-dependent neuroprotective effect. Neuroprotective effects of fluoxetine were abolished by inhibition of PI3K, Akt, and PKA using LY294002, KRX-0401, and H89, respectively. Treatment of PC12 cells with fluoxetine resulted in increased phosphorylation of Akt, FoxO3a, and CREB. Fluoxetine also dose-dependently rescued the phosphorylation levels of Akt, FoxO3a, and CREB, following administration of CORT (from 99 to 110, 56 to 170, 80 to 170 %, respectively). In addition, inhibition of PKA and PI3K/Akt resulted in decreased levels of p-CREB, p-Akt, and p-FoxO3a in the presence of fluoxetine. Furthermore, fluoxetine reversed CORT-induced upregulation of p53-upregulated modulator of apoptosis (Puma) and Bcl-2-interacting mediator of cell death (Bim) via the PI3K/Akt/FoxO3a signaling pathway. H89 treatment reversed the effect of fluoxetine on the mRNA level of brain-derived neurotrophic factor, which was decreased in the presence of CORT. Our data indicate that fluoxetine elicited neuroprotection toward CORT-induced cell death that involves dual regulation from PI3K/Akt/FoxO3a and PKA/CREB pathways. PMID:27412469

  8. Astragalus Polysaccharide Suppresses Doxorubicin-Induced Cardiotoxicity by Regulating the PI3k/Akt and p38MAPK Pathways

    PubMed Central

    Cao, Yuan; Ruan, Yang; Shen, Tao; Huang, Xiuqing; Li, Meng; Yu, Weiwei; Zhu, Yuping; Man, Yong; Wang, Shu; Li, Jian

    2014-01-01

    Background. Doxorubicin, a potent chemotherapeutic agent, is associated with acute and chronic cardiotoxicity, which is cumulatively dose-dependent. Astragalus polysaccharide (APS), the extract of Astragalus membranaceus with strong antitumor and antiglomerulonephritis activity, can effectively alleviate inflammation. However, whether APS could ameliorate chemotherapy-induced cardiotoxicity is not understood. Here, we investigated the protective effects of APS on doxorubicin-induced cardiotoxicity and elucidated the underlying mechanisms of the protective effects of APS. Methods. We analyzed myocardial injury in cancer patients who underwent doxorubicin chemotherapy and generated a doxorubicin-induced neonatal rat cardiomyocyte injury model and a mouse heart failure model. Echocardiography, reactive oxygen species (ROS) production, TUNEL, DNA laddering, and Western blotting were performed to observe cell survival, oxidative stress, and inflammatory signal pathways in cardiomyocytes. Results. Treatment of patients with the chemotherapeutic drug doxorubicin led to heart dysfunction. Doxorubicin reduced cardiomyocyte viability and induced C57BL/6J mouse heart failure with concurrent elevated ROS generation and apoptosis, which, however, was attenuated by APS treatment. In addition, there was profound inhibition of p38MAPK and activation of Akt after APS treatment. Conclusions. These results demonstrate that APS could suppress oxidative stress and apoptosis, ameliorating doxorubicin-mediated cardiotoxicity by regulating the PI3k/Akt and p38MAPK pathways. PMID:25386226

  9. Implication of PI3K/Akt pathway in pancreatic cancer: When PI3K isoforms matter?

    PubMed

    Baer, Romain; Cintas, Célia; Therville, Nicole; Guillermet-Guibert, Julie

    2015-09-01

    Pancreatic cancer belongs to the incurable family of solid cancers. Despite of a recent better understanding its molecular biology, and an increased number of clinical trials, there is still a lack for innovative targeted therapies to fight this deadly malignancy. PI3K/Akt signalling is one of the most commonly deregulated signalling pathways in cancer, which explains the massive attention from many pharmaceutical companies over the ten past years on these signalling molecules. The already developed small molecule inhibitors are currently under clinical trial in various cancer types. Class I PI3Ks have 4 isoforms for which the role in physiology starts to be well described in the literature. Data are more unclear for their differential involvement in oncogenesis. In this review, we will discuss about the cognitive and therapeutic potential of targeting this signalling pathway and in particular Class I PI3K isoforms for pancreatic cancer treatment. Isoform-specificity of PI3K inhibitors are currently designed to achieve the same goal as pan-PI3K inhibitors but without potential adverse effects. We will discuss if such strategy is relevant in pancreatic adenocarcinoma.

  10. PDGF stimulation of Mueller cell proliferation: Contributions of c-JNK and the PI3K/Akt pathway

    SciTech Connect

    Moon, Sang Woong; Chung, Eun Jee; Jung, Sun-Ah; Lee, Joon H.

    2009-10-09

    Platelet-derived growth factor (PDGF) has a critical role in proliferative vitreoretinopathy (PVR) as a chemoattractant and mitogen for retinal pigment epithelial cells and retinal glial cells. Here, we investigated the potential effects of PDGF on the proliferation of Mueller cells and the intracellular signaling pathway mediating these changes. PDGF induced Mueller cell proliferation and increased phosphorylation of the PDGF receptor (PDGFR), as shown by an MTT assay and immunoprecipitation analyses. Both effects were blocked by JNJ, a PDGFR-selective tyrosine kinase inhibitor. PDGF also stimulated phosphorylation of c-JNK and Akt. PDGF-induced Mueller cell proliferation was significantly reduced by pre-treatment with SP600125 and LY294002, inhibitors of c-JNK and Akt phosphorylation, respectively. Our findings collectively indicate that PDGF-stimulated Mueller cell proliferation occurs via activation of the c-JNK and PI3K/Akt signaling pathways. These data provide useful information in establishing the role of Mueller cells in the development of proliferative vitreoretinopathy.

  11. Basic fibroblast growth factor promotes melanocyte migration via activating PI3K/Akt-Rac1-FAK-JNK and ERK signaling pathways.

    PubMed

    Shi, Hongxue; Lin, Beibei; Huang, Yan; Wu, Jiang; Zhang, Hongyu; Lin, Cai; Wang, Zhouguang; Zhu, Jingjing; Zhao, Yingzhen; Fu, Xiaobing; Lou, Zhencai; Li, Xiaokun; Xiao, Jian

    2016-09-01

    Vitiligo is a depigmentation disorder characterized by loss of functional melanocytes of the skin epidermis. The pathogenesis of vitiligo remains elusive. The purpose of this study is to investigate the effects of basic fibroblast growth factor (bFGF) on melanocyte migration, including its biochemical mechanism using transwell assay in vitro. We found that melanocyte treated with bFGF showed a significant increase in migration and cytoskeletal rearrangement. These changes were associated with increased activation of PI3K/Akt, Rac1, FAK, JNK, and ERK. Likewise, reduction of PI3K/Akt, Rac1, FAK, JNK, and ERK activity using selective inhibitors or siRNA was associated with impediment of bFGF-induced melanocyte migration. In addition, activity of Rac1, FAK, and JNK was reduced in cells in which PI3K/Akt was inhibited, activity of FAK and JNK was reduced in cells in which the Rac1 was inhibited, and activity of JNK was reduced in cells in which the FAK was inhibited. Collectively, these data demonstrate that bFGF facilitated melanocyte migration via PI3K/Akt-Rac1-FAK-JNK and ERK signaling pathways. © 2016 IUBMB Life, 68(9):735-747, 2016. PMID:27350596

  12. Ochratoxin A activates opposing c-MET/PI3K/Akt and MAPK/ERK 1-2 pathways in human proximal tubule HK-2 cells.

    PubMed

    Özcan, Zeynep; Gül, Gizem; Yaman, Ibrahim

    2015-08-01

    Ochratoxin A (OTA) is a mycotoxin produced as a secondary metabolite by filamentous fungi, such as Aspergillus and Penicillium. Because OTA is a common contaminant of food and feeds, humans and animals are frequently exposed to OTA in daily life. It has been classified as a carcinogen in rodents and a possible carcinogen in humans. OTA has been shown to deregulate a variety of different signal transduction pathways in a cell type- and dosage-depending manner resulting in contrasting physiological effects, such as survival or cell death. While the ERK1-2 and JNK/SAPK MAPK pathways are major targets, knowledge about their role in OTA-mediated cell survival and death is fragmented. Similarly, the contribution of the PI3K/Akt pathway to the carcinogenic effect of OTA in proximal tubule cells has not been elucidated in detail. In this study, we demonstrated that OTA induced sustained activation of the PI3K/Akt and MEK/ERK1-2 signaling pathways in a dose- and time-dependent manner in HK-2 cells. Chemical inhibition of ERK1-2 activation or overexpression of dominant-negative and kinase-dead MEK1 leads to increased cell viability and decreased apoptosis in OTA-treated cells. Blockage of PI3K/Akt with Wortmannin aggravated the negative effect of OTA on cell viability and increased the levels of apoptosis. Moreover, we identified the c-MET proto-oncogene as an upstream receptor tyrosine kinase responsible for OTA-induced activation of PI3K/Akt signaling in HK-2 cells. Our data suggest that OTA may potentiate carcinogenesis by sustained activation of c-MET/PI3K/Akt signaling through suppression of apoptosis induced by MEK/ERK1-2 activation in damaged renal proximal tubule epithelial cells. PMID:25002221

  13. Id-1 promotes osteosarcoma cell growth and inhibits cell apoptosis via PI3K/AKT signaling pathway.

    PubMed

    Hao, Liang; Liao, Qi; Tang, Qiang; Deng, Huan; Chen, Lu

    2016-02-12

    Accumulating evidence reveals that Id-1 is upregulated and functions as a potential tumor promoter in several human cancer types. However, the role of Id-1 in osteosarcoma (OS) is unknown. In present study, we found that Id-1 expression was elevated in OS tissues than adjacent normal bone tissues. More importantly, we demonstrated that overexpression of Id-1 is significantly correlated with tumor progression and poor survival in OS patients. Furthermore, increased expression of Id-1 was observed in OS cell lines and ectopic expression of Id-1 significantly enhanced in vitro cell proliferation and promoted in vivo tumor growth, whereas knockdown of Id-1 suppressed OS cells growth. Moreover, our experimental data revealed that Id-1 promotes cell proliferation by facilitating cell cycle progression and inhibits cell apoptosis. Mechanistically, the effects of Id-1 in OS cells is at least partly through activation of PI3K/Akt signaling pathway. Therefore, we identified a tumorigenic role of Id-1 in OS and suggested a potential therapeutic target for OS patients.

  14. Involvement of the PI3K/Akt signal pathway in the hypoglycemic effects of tea polysaccharides on diabetic mice.

    PubMed

    Li, Shuqin; Chen, Haixia; Wang, Jia; Wang, Xiuming; Hu, Bo; Lv, Funing

    2015-11-01

    In order to investigate the hypoglycemic effects and potential mechanism of tea polysaccharides (TPS) on diabetes, type 2 diabetes mellitus (T2DM) mice were established and treated with TPS. Results showed that TPS treatment could result in the increase of body weight and the decrease of blood glucose in the diabetic mice. The contents of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) were decreased significantly (p<0.05) while the contents of triglyceride (TG) and (high-density lipoprotein cholesterol) HDL-c were almost restored to the normal levels. TPS possessed the efficacy of insulin resistance alleviation and exerted obvious cytoprotective action. The enzyme activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) were notably improved in both liver and kidney tissues (p<0.05) after the treatment of TPS. Furthermore, the expressions of PI3Kp85/p-Akt/GLUT4 were upregulated by TPS, which indicated the involvement of the PI3K/Akt signal pathway in the hypoglycemic mechanism of TPS. Results suggested that TPS could ameliorate the T2MD and might be a promising candidate functional food or medicine for T2DM treatment.

  15. Dipsacus asperoides polysaccharide induces apoptosis in osteosarcoma cells by modulating the PI3K/Akt pathway.

    PubMed

    Chen, Jun; Yao, Dong; Yuan, Huixin; Zhang, Shaojun; Tian, Jinhong; Guo, Wenjing; Liang, Weizhi; Li, Huiyuan; Zhang, Yong

    2013-06-20

    An alkaline extractable and water-soluble polysaccharide (ADAPW), with an average molecular weight of 16kDa, was purified from the alkaline extraction of the roots of Dipsacus asperoides. Monosaccharide component analysis indicated that ADAPW was composed of glucose, rhamnose, arabinose and mannose in a molar ratio of 8.54:1.83:1.04:0.42. This study aimed to investigate the effect of ADAPW on the viability of human osteosarcoma cell line HOS cells, and explore the possible mechanisms. The results revealed that ADAPW inhibited the proliferation of HOS cells in a dose-dependent manner by inducing apoptosis. Furthermore, treatment with ADAPW caused a loss of mitochondrial membrane potential and accumulation of reactive oxygen species (ROS). In addition, Western blot analysis demonstrated that ADAPW down-regulated the protein expressions of PI3K and phosphorylated Akt (pAkt) in HOS cells. Taken together, induction of apoptosis on HOS cells by ADAPW was mainly associated with ROS production, mitochondrial dysfunction, and inhibition of PI3K/Akt signaling pathway. So this finding suggests that ADAPW may be potentially effective in cancer prevention against human osteosarcoma. PMID:23648042

  16. α-Lipoic acid inhibits sevoflurane-induced neuronal apoptosis through PI3K/Akt signalling pathway.

    PubMed

    Ma, Rong; Wang, Xiang; Peng, Peipei; Xiong, Jingwei; Dong, Hongquan; Wang, Lixia; Ding, Zhengnian

    2016-01-01

    Sevoflurane is a widely used anaesthetic agent, including in anaesthesia of children and infants. Recent studies indicated that the general anaesthesia might cause the cell apoptosis in the brain. This issue raises the concerns about the neuronal toxicity induced by the application of anaesthetic agents, especially in the infants and young children. In this study, we used Morris water maze, western blotting and immunohistochemistry to elucidate the role of α-lipoic acid in the inhibition of neuronal apoptosis. We found that sevoflurane led to the long-term cognitive impairment in the young rats. This adverse effect may be caused by the neuronal death in the hippocampal region, mediated through PI3K/Akt signalling pathway. We also showed that α-lipoic acid offset the effect of sevoflurane on the neuronal apoptosis and cognitive dysfunction. This study elucidated the potential clinical role of α-lipoic acid, providing a promising way in the prevention and treatment of long-term cognitive impairment induced by sevoflurane general anesthesia.

  17. [Insulin promotes proliferation of skeletal myoblast cells through PI3K/Akt and MEK/ERK pathways in rats].

    PubMed

    Yu, Huan; Zhang, Min; Zhao, Yong; Wu, Ping; Chen, Pei-Liang; Li, Wei-Dong

    2013-02-25

    The present study was to explore the effects of insulin on proliferation of skeletal myoblast cells in rats. Separated and cultured primary skeletal myoblast cells from rats were treated by insulin. By means of the incorporation of (3)H-TdR, BrdU assay and MTT assay, the proliferation of skeletal myoblast cells was detected. Western blot was used to check the phosphorylation of Akt and ERK of myoblast cells. The results showed that insulin significantly promoted the incorporation of (3)H-TdR into cultured skeletal myoblast cells in a dose-dependent manner. MTT assay and BrdU assay also showed insulin promoted the proliferation of skeletal myoblast cells. The promotion of skeletal myoblast cells proliferation by insulin was inhibited by PI3K inhibitor wortmannin or MEK inhibitor U0126, and the same phenomenon was shown in L6 and C2C12 cells. Also, insulin increased the phosphorylation of Akt and ERK in myoblast cells. These results suggest that insulin may promote proliferation of skeletal myoblast cells through PI3K/Akt and MEK/ERK pathways.

  18. c-Yes enhances tumor migration and invasion via PI3K/AKT pathway in epithelial ovarian cancer.

    PubMed

    Jin, Yunfeng; Huang, Menghui; Wang, Yingying; Yi, Changying; Deng, Yan; Chen, Yannan; Jiang, Lifei; Wang, Juan; Shen, Qin; Liu, Rong; QinghuaXi

    2016-08-01

    Overexpression of c-Yes has been noted to correlation with several human cancers. However, the effects of c-Yes on epithelial ovarian cancer (EOC) development remain unclear. The aim of this study is going to prove the effects of c-Yes and related mechanisms in proliferation, metastasis and invasion of EOC. Immunohistochemical analysis was performed in 119 human EOC samples, and the data was correlated with clinic pathologic features. Furthermore, western blot analysis is performed for c-Yes in EOC samples and cell lines to evaluate their protein levels and molecular interaction. Kaplan-Meier survival analysis shows that the strong expression of c-Yes exhibited a significant correlation with poor prognosis in human EOC (P<0.01(⁎)). Meanwhile, we found that knockdown of c-Yes by shRNA inhibited the ability of migration and invasion in EOC cells via the PI3K/AKT pathway. In a word, these results suggested that c-Yes plays an important role in migration and invasion of EOC.

  19. Reciprocal positive regulation between Cx26 and PI3K/Akt pathway confers acquired gefitinib resistance in NSCLC cells via GJIC-independent induction of EMT

    PubMed Central

    Yang, J; Qin, G; Luo, M; Chen, J; Zhang, Q; Li, L; Pan, L; Qin, S

    2015-01-01

    Gefitinib efficiency in non-small-cell lung cancer (NSCLC) therapy is limited due to development of drug resistance. The molecular mechanisms of gefitinib resistance remain still unclear. In this study, we first found that connexin 26 (Cx26) is the predominant Cx isoform expressed in various NSCLC cell lines. Then, two gefitinib-resistant (GR) NSCLC cell lines, HCC827 GR and PC9 GR, from their parental cells were established. In these GR cells, the results showed that gefitinib resistance correlated with changes in cellular EMT phenotypes and upregulation of Cx26. Cx26 was detected to be accumulated in the cytoplasm and failed to establish functional gap-junctional intercellular communication (GJIC) either in GR cells or their parental cells. Ectopic expression of GJIC-deficient chimeric Cx26 was sufficient to induce EMT and gefitinib insensitivity in HCC827 and PC9 cells, while knockdown of Cx26 reversed EMT and gefitinib resistance in their GR cells both in vitro and in vivo. Furthermore, Cx26 overexpression could activate PI3K/Akt signaling in these cells. Cx26-mediated EMT and gefitinib resistance were significantly blocked by inhibition of PI3K/Akt pathway. Specifically, inhibition of the constitutive activation of PI3K/Akt pathway substantially suppressed Cx26 expression, and Cx26 was confirmed to functionally interplay with PI3K/Akt signaling to promote EMT and gefitinib resistance in NSCLC cells. In conclusion, the reciprocal positive regulation between Cx26 and PI3K/Akt signaling contributes to acquired gefitinib resistance in NSCLC cells by promoting EMT via a GJIC-independent manner. PMID:26203858

  20. Activation of PI3K-Akt-GSK3{beta} pathway mediates hepatocyte growth factor inhibition of RANTES expression in renal tubular epithelial cells

    SciTech Connect

    Gong Rujun . E-mail: rgong@Brown.edu; Rifai, Abdalla; Dworkin, Lance D.

    2005-04-29

    Hepatocyte growth factor (HGF) was recently reported to ameliorate renal inflammation in a rat model of chronic renal failure. HGF exerted its action through suppression of RANTES expression in renal tubules. In the present study, we utilized an in vitro model of human kidney proximal tubule epithelial cells (HKC) to elucidate the mechanisms of RANTES suppression by HGF. HGF significantly suppressed basal and TNF-{alpha}-induced mRNA and protein expression of RANTES in a time and dose dependent fashion. HGF elicited PI3K-Akt activation and inhibited GSK3, a downstream transducer of PI3K-Akt, by inhibitory phosphorylation at Ser-9. When the PI3K-Akt pathway was blocked by wortmannin, HGF inhibition of RANTES was abrogated, demonstrating that the PI3K-Akt pathway is necessary for HGF action. In addition, specific inhibition of GSK3 activity by lithium ion suppressed basal and TNF-{alpha}-induced RANTES expression, reminiscent of the action of HGF. To further investigate the role of GSK3 in modulating RANTES expression, we examined the effect of forced expression of wild type GSK3{beta} or an uninhibitable mutant GSK3{beta}, in which the regulatory Ser-9 residue is changed to alanine (S9A-GSK3{beta}) in HKC. Overexpression of wild type GSK3{beta} did not alter the inhibitory action of HGF on RANTES. In contrast, expression of S9A-GSK3{beta} abolished HGF inhibition of basal and TNF-{alpha} stimulated RANTES expression. These findings suggest that PI3K-Akt activation and subsequent inhibitory phosphorylation of GSK3{beta} are required for HGF-induced suppression of RANTES in HKC.

  1. RICTOR involvement in the PI3K/AKT pathway regulation in melanocytes and melanoma

    PubMed Central

    Laugier, Florence; Finet-Benyair, Adeline; André, Jocelyne; Rachakonda, P. Sivaramakrishna; Kumar, Rajiv; Bensussan, Armand; Dumaz, Nicolas

    2015-01-01

    Several studies have highlighted the importance of the PI3K pathway in melanocytes and its frequent over-activation in melanoma. However, little is known about regulation of the PI3K pathway in melanocytic cells. We showed that normal human melanocytes are less sensitive to selective PI3K or mTOR inhibitors than to dual PI3K/mTOR inhibitors. The resistance to PI3K inhibitor was due to a rapid AKT reactivation limiting the inhibitor effect on proliferation. Reactivation of AKT was linked to a feedback mechanism involving the mTORC2 complex and in particular its scaffold protein RICTOR. RICTOR overexpression in melanocytes disrupted the negative feedback, activated the AKT pathway and stimulated clonogenicity highlighting the importance of this feedback to restrict melanocyte proliferation. We found that the RICTOR locus is frequently amplified and overexpressed in melanoma and that RICTOR over-expression in NRAS-transformed melanocytes stimulates their clonogenicity, demonstrating that RICTOR amplification can cooperate with NRAS mutation to stimulate melanoma proliferation. These results show that RICTOR plays a central role in PI3K pathway negative feedback in melanocytes and that its deregulation could be involved in melanoma development. PMID:26356562

  2. RICTOR involvement in the PI3K/AKT pathway regulation in melanocytes and melanoma.

    PubMed

    Laugier, Florence; Finet-Benyair, Adeline; André, Jocelyne; Rachakonda, P Sivaramakrishna; Kumar, Rajiv; Bensussan, Armand; Dumaz, Nicolas

    2015-09-29

    Several studies have highlighted the importance of the PI3K pathway in melanocytes and its frequent over-activation in melanoma. However, little is known about regulation of the PI3K pathway in melanocytic cells. We showed that normal human melanocytes are less sensitive to selective PI3K or mTOR inhibitors than to dual PI3K/mTOR inhibitors. The resistance to PI3K inhibitor was due to a rapid AKT reactivation limiting the inhibitor effect on proliferation. Reactivation of AKT was linked to a feedback mechanism involving the mTORC2 complex and in particular its scaffold protein RICTOR. RICTOR overexpression in melanocytes disrupted the negative feedback, activated the AKT pathway and stimulated clonogenicity highlighting the importance of this feedback to restrict melanocyte proliferation. We found that the RICTOR locus is frequently amplified and overexpressed in melanoma and that RICTOR over-expression in NRAS-transformed melanocytes stimulates their clonogenicity, demonstrating that RICTOR amplification can cooperate with NRAS mutation to stimulate melanoma proliferation. These results show that RICTOR plays a central role in PI3K pathway negative feedback in melanocytes and that its deregulation could be involved in melanoma development.

  3. Opisthorchis viverrini infection activates the PI3K/ AKT/PTEN and Wnt/β-catenin signaling pathways in a Cholangiocarcinogenesis model.

    PubMed

    Yothaisong, Supak; Thanee, Malinee; Namwat, Nisana; Yongvanit, Puangrat; Boonmars, Thidarut; Puapairoj, Anucha; Loilome, Watcharin

    2014-01-01

    Opisthorchis viverrini (Ov) infection is the major etiological factor for cholangiocarcinoma (CCA), especially in northeast Thailand. We have previously reported significant involvement of PI3K/AKT/PTEN and Wnt/β- catenin in human CCA tissues. The present study, therefore, examined the expression and activation of PI3K/ AKT/PTEN and Wnt/β-catenin signaling components during Ov-induced cholangiocarcinogenesis in a hamster animal model. Hamsters were divided into two groups; non-treated and Ov plus NDMA treated. The results of immunohistochemical staining showed an upregulation of PI3K/AKT signaling as determined by elevated expression of the p85α-regulatory and p110α-catalytic subunits of PI3K as well as increased expression and activation of AKT during cholangiocarcinogenesis. Interestingly, the staining intensity of activated AKT (p-AKT) increased in the apical regions of the bile ducts and strong staining was detected where the liver fluke resides. Moreover, PTEN, a negative regulator of PI3K/AKT, was suppressed by decreased expression and increased phosphorylation during cholangiocarcinogenesis. We also detected upregulation of Wnt/β-catenin signaling as determined by increased positive staining of Wnt3, Wnt3a, Wnt5a, Wnt7b and β-catenin, corresponded with the period of cholangiocarcinogenesis. Furthermore, nuclear staining of β-catenin was observed in CCA tissues. Our results suggest the liver fluke infection causes chronic inflammatory conditions which lead to upregulation of the PI3K/AKT and Wnt/β-catenin signaling pathways which may drive CCA carcinogenesis. These results provide useful information for drug development, prevention and treatment of CCA. PMID:25556493

  4. Myrcia bella Leaf Extract Presents Hypoglycemic Activity via PI3k/Akt Insulin Signaling Pathway

    PubMed Central

    Vareda, Priscilla Maria Ponce; Saldanha, Luiz Leonardo; Camaforte, Nathalia Aparecida de Paula; Violato, Natalia Moretti; Dokkedal, Anne Lígia; Bosqueiro, José Roberto

    2014-01-01

    Species of Myrcia are used by indigenous people and in traditional communities in Brazil for the treatment of Diabetes mellitus. We investigated the hypoglycemic effect of the extract of leaves of Myrcia bella in diabetic mice. The chemical fingerprinting of the 70% EtOH extract characterized as main constituents flavonoid aglycones, flavonoid-O-glycosides, and acylated flavonoid-O-glycosides derivatives of quercetin and myricetin. Mice were treated with saline or extract of M. bella (300 or 600 mg/Kg b.w.) for 14 days. Body weight and water and food intake were measured every day. Fasting blood glucose was measured weekly. At the end of the treatment, blood insulin, triglycerides, total cholesterol, and protein were measured. Glycogen content and expression of proteins of the insulin signaling pathway were measured in liver. The treatment with 600 mg/Kg reduced the fasting blood glucose in diabetic mice of the 7th day as water and food intake and increased hepatic glycogen. Total cholesterol and triglycerides were reduced in diabetic treated mice. The treatment increased the expression of IRS-1, PI3-K, and AKT in the livers of diabetic treated mice. The results indicate that the extract of the leaves of Myrcia bella has hypoglycemic properties and possibly acts to regulate glucose uptake by the liver. PMID:24872834

  5. Abnormal Protein Glycosylation and Activated PI3K/Akt/mTOR Pathway: Role in Bladder Cancer Prognosis and Targeted Therapeutics

    PubMed Central

    Lima, Luís; Peixoto, Andreia; Fernandes, Elisabete; Neves, Diogo; Neves, Manuel; Gaiteiro, Cristiana; Tavares, Ana; Gil da Costa, Rui M.; Cruz, Ricardo; Amaro, Teresina; Oliveira, Paula A.; Ferreira, José Alexandre; Santos, Lúcio L.

    2015-01-01

    Muscle invasive bladder cancer (MIBC, stage ≥T2) is generally associated with poor prognosis, constituting the second most common cause of death among genitourinary tumours. Due to high molecular heterogeneity significant variations in the natural history and disease outcome have been observed. This has also delayed the introduction of personalized therapeutics, making advanced stage bladder cancer almost an orphan disease in terms of treatment. Altered protein glycosylation translated by the expression of the sialyl-Tn antigen (STn) and its precursor Tn as well as the activation of the PI3K/Akt/mTOR pathway are cancer-associated events that may hold potential for patient stratification and guided therapy. Therefore, a retrospective design, 96 bladder tumours of different stages (Ta, T1-T4) was screened for STn and phosphorylated forms of Akt (pAkt), mTOR (pmTOR), S6 (pS6) and PTEN, related with the activation of the PI3K/Akt/mTOR pathway. In our series the expression of Tn was residual and was not linked to stage or outcome, while STn was statically higher in MIBC when compared to non-muscle invasive tumours (p = 0.001) and associated decreased cancer-specific survival (log rank p = 0.024). Conversely, PI3K/Akt/mTOR pathway intermediates showed an equal distribution between non-muscle invasive bladder cancer (NMIBC) and MIBC and did not associate with cancer-specif survival (CSS) in any of these groups. However, the overexpression of pAKT, pmTOR and/or pS6 allowed discriminating STn-positive advanced stage bladder tumours facing worst CSS (p = 0.027). Furthermore, multivariate Cox regression analysis revealed that overexpression of PI3K/Akt/mTOR pathway proteins in STn+ MIBC was independently associated with approximately 6-fold risk of death by cancer (p = 0.039). Mice bearing advanced stage chemically-induced bladder tumours mimicking the histological and molecular nature of human tumours were then administrated with mTOR-pathway inhibitor sirolimus (rapamycin

  6. Abnormal Protein Glycosylation and Activated PI3K/Akt/mTOR Pathway: Role in Bladder Cancer Prognosis and Targeted Therapeutics.

    PubMed

    Costa, Céu; Pereira, Sofia; Lima, Luís; Peixoto, Andreia; Fernandes, Elisabete; Neves, Diogo; Neves, Manuel; Gaiteiro, Cristiana; Tavares, Ana; Gil da Costa, Rui M; Cruz, Ricardo; Amaro, Teresina; Oliveira, Paula A; Ferreira, José Alexandre; Santos, Lúcio L

    2015-01-01

    Muscle invasive bladder cancer (MIBC, stage ≥T2) is generally associated with poor prognosis, constituting the second most common cause of death among genitourinary tumours. Due to high molecular heterogeneity significant variations in the natural history and disease outcome have been observed. This has also delayed the introduction of personalized therapeutics, making advanced stage bladder cancer almost an orphan disease in terms of treatment. Altered protein glycosylation translated by the expression of the sialyl-Tn antigen (STn) and its precursor Tn as well as the activation of the PI3K/Akt/mTOR pathway are cancer-associated events that may hold potential for patient stratification and guided therapy. Therefore, a retrospective design, 96 bladder tumours of different stages (Ta, T1-T4) was screened for STn and phosphorylated forms of Akt (pAkt), mTOR (pmTOR), S6 (pS6) and PTEN, related with the activation of the PI3K/Akt/mTOR pathway. In our series the expression of Tn was residual and was not linked to stage or outcome, while STn was statically higher in MIBC when compared to non-muscle invasive tumours (p = 0.001) and associated decreased cancer-specific survival (log rank p = 0.024). Conversely, PI3K/Akt/mTOR pathway intermediates showed an equal distribution between non-muscle invasive bladder cancer (NMIBC) and MIBC and did not associate with cancer-specif survival (CSS) in any of these groups. However, the overexpression of pAKT, pmTOR and/or pS6 allowed discriminating STn-positive advanced stage bladder tumours facing worst CSS (p = 0.027). Furthermore, multivariate Cox regression analysis revealed that overexpression of PI3K/Akt/mTOR pathway proteins in STn+ MIBC was independently associated with approximately 6-fold risk of death by cancer (p = 0.039). Mice bearing advanced stage chemically-induced bladder tumours mimicking the histological and molecular nature of human tumours were then administrated with mTOR-pathway inhibitor sirolimus (rapamycin

  7. Abnormal Protein Glycosylation and Activated PI3K/Akt/mTOR Pathway: Role in Bladder Cancer Prognosis and Targeted Therapeutics.

    PubMed

    Costa, Céu; Pereira, Sofia; Lima, Luís; Peixoto, Andreia; Fernandes, Elisabete; Neves, Diogo; Neves, Manuel; Gaiteiro, Cristiana; Tavares, Ana; Gil da Costa, Rui M; Cruz, Ricardo; Amaro, Teresina; Oliveira, Paula A; Ferreira, José Alexandre; Santos, Lúcio L

    2015-01-01

    Muscle invasive bladder cancer (MIBC, stage ≥T2) is generally associated with poor prognosis, constituting the second most common cause of death among genitourinary tumours. Due to high molecular heterogeneity significant variations in the natural history and disease outcome have been observed. This has also delayed the introduction of personalized therapeutics, making advanced stage bladder cancer almost an orphan disease in terms of treatment. Altered protein glycosylation translated by the expression of the sialyl-Tn antigen (STn) and its precursor Tn as well as the activation of the PI3K/Akt/mTOR pathway are cancer-associated events that may hold potential for patient stratification and guided therapy. Therefore, a retrospective design, 96 bladder tumours of different stages (Ta, T1-T4) was screened for STn and phosphorylated forms of Akt (pAkt), mTOR (pmTOR), S6 (pS6) and PTEN, related with the activation of the PI3K/Akt/mTOR pathway. In our series the expression of Tn was residual and was not linked to stage or outcome, while STn was statically higher in MIBC when compared to non-muscle invasive tumours (p = 0.001) and associated decreased cancer-specific survival (log rank p = 0.024). Conversely, PI3K/Akt/mTOR pathway intermediates showed an equal distribution between non-muscle invasive bladder cancer (NMIBC) and MIBC and did not associate with cancer-specif survival (CSS) in any of these groups. However, the overexpression of pAKT, pmTOR and/or pS6 allowed discriminating STn-positive advanced stage bladder tumours facing worst CSS (p = 0.027). Furthermore, multivariate Cox regression analysis revealed that overexpression of PI3K/Akt/mTOR pathway proteins in STn+ MIBC was independently associated with approximately 6-fold risk of death by cancer (p = 0.039). Mice bearing advanced stage chemically-induced bladder tumours mimicking the histological and molecular nature of human tumours were then administrated with mTOR-pathway inhibitor sirolimus (rapamycin

  8. PI3K/AKT pathway regulates E-cadherin and Desmoglein 2 in aggressive prostate cancer

    PubMed Central

    Barber, Alison G; Castillo-Martin, Mireia; Bonal, Dennis M; Jia, Angela J; Rybicki, Benjamin A; Christiano, Angela M; Cordon-Cardo, Carlos

    2015-01-01

    Reduced expression of both classical and desmosomal cadherins has been associated with different types of carcinomas, including prostate cancer. This study aims to provide a comprehensive view of the role and regulation of cell–cell adhesion in prostate cancer aggressiveness by examining the functional implications of both E-cadherin and Desmoglein 2 (DSG2). E-cadherin expression was first examined using immunofluorescence in 50 normal prostate tissues and in a cohort of 414 prostate cancer patients. Correlation and survival analyses were performed to assess its clinical significance. In primary prostate cancer patients, reduced expression of both E-cadherin and DSG2 is significantly associated with an earlier biochemical recurrence. Transgenic DU145 E-cadherin knockdown and constitutively active AKT overexpression lines were generated. Functional implications of such genetic alterations were analyzed in vitro and in vivo, the latter by using tumorigenesis as well as extravasation and metastatic tumor formation assays. We observed that loss of E-cadherin leads to impaired primary and metastatic tumor formation in vivo, suggesting a tumor promoter role for E-cadherin in addition to its known role as a tumor suppressor. Activation of AKT leads to a significant reduction in E-cadherin expression and nuclear localization of Snail, suggesting a role for the PI3K/AKT signaling pathway in the transient repression of E-cadherin. This reduced expression may be regulated by separate mechanisms as neither the loss of E-cadherin nor activation of AKT significantly affected DSG2 expression. In conclusion, these findings illustrate the critical role of cell–cell adhesion in the progression to aggressive prostate cancer, through regulation by the PI3K pathway. PMID:26033689

  9. Vitamin E succinate induces apoptosis via the PI3K/AKT signaling pathways in EC109 esophageal cancer cells.

    PubMed

    Yang, Peng; Zhao, Jiaying; Hou, Liying; Yang, Lei; Wu, Kun; Zhang, Linyou

    2016-08-01

    Esophageal cancer is the fourth most common gastrointestinal cancer, it generally has a poor prognosis and novel strategies are required for prevention and treatment. Vitamin E succinate (VES) is a potential chemical agent for cancer prevention and therapy as it exerts anti‑tumor effects in a variety of cancers. However, the role of VES in tumorigenesis and progression of cancer remains to be elucidated. The present study aimed to determine the effects of VES in regulating the survival and apoptosis of human esophageal cancer cells. EC109 human esophageal cancer cells were used to investigate the anti‑proliferative effects of VES. The MTT and Annexin V‑fluorescein isothiocyanate/propidium iodide assays demonstrated that VES inhibited cell proliferation and induced apoptosis in esophageal cancer cells. Furthermore, VES downregulated constitutively active basal levels of phosphorylated (p)‑serine‑threonine kinase AKT (AKT) and p‑mammalian target of rapamycin (mTOR), and decreased the phosphorylation of AKT substrates Bcl‑2‑associated death receptor and caspase‑9, in addition to mTOR effectors, ribosomal protein S6 kinase β1 and eIF4E‑binding protein 1. Phosphoinositide‑3‑kinase (PI3K) inhibitor, LY294002 suppressed p‑AKT and p‑mTOR, indicating PI3K is a common upstream mediator. The apoptosis induced by VES was increased by inhibition of AKT or mTOR with their respective inhibitor in esophageal cancer cells. The results of the present study suggested that VES targeted the PI3K/AKT signaling pathways and induced apoptosis in esophageal cancer cells. Furthermore, the current study suggests that VES may be useful in a combinational therapeutic strategy employing an mTOR inhibitor.

  10. MALAT1 promotes the proliferation and metastasis of osteosarcoma cells by activating the PI3K/Akt pathway.

    PubMed

    Dong, Yongqiang; Liang, Guojun; Yuan, Bo; Yang, Chaoqun; Gao, Rui; Zhou, Xuhui

    2015-03-01

    Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), one of the first found cancer-associated long noncoding RNAs (lncRNAs), involves in the development and progression of many types of tumors. An aberrant expression of MALAT1 was observed in hepatocellular carcinoma, cervical cancer, breast cancer, ovarian cancer, and colorectal cancer. However, the exact effects and molecular mechanisms of MALAT1 in osteosarcoma progression are still unknown up to now. Here, we investigated the role of MALAT1 in human osteosarcoma cell lines and clinical tumor samples in order to determine the function of this molecule. In our research, the MALAT1 messenger RNA (mRNA) was highly expressed in human osteosarcoma tissues, and its expression level was closely correlated with pulmonary metastasis. Then, we employed lentivirus-mediated knockdown of MALAT1 in U-2 OS and SaO2 to determine the role of MALAT1 in osteosarcoma cell lines. Lentivirus-mediated MALAT1 small interfering RNA (siRNA) could efficiently downregulated the expression level of MALAT1 in osteosarcoma cell lines. Knockdown of MALAT1 inhibited the proliferation and invasion of human osteosarcoma cell and suppressed its metastasis in vitro and vivo. At the same time, the proliferating cell nuclear antigen (PCNA), matrix metallopeptidase 9 (MMP-9), phosphorylated PI3Kp85α, and Akt expressions were significantly inhibited in MALAT1-deleted cells. These findings indicated that MALAT1 might suppress the tumor growth and metastasis via PI3K/AKT signaling pathway. Taken together, our data indicated that MALAT1 might be an oncogenic lncRNA that promoted proliferation and metastasis of osteosarcoma and could be regarded as a therapeutic target in human osteosarcoma.

  11. Polysaccharides from the root of Angelica sinensis promotes hematopoiesis and thrombopoiesis through the PI3K/AKT pathway

    PubMed Central

    2010-01-01

    the PI3K/AKT pathway. PMID:21176128

  12. Apelin-36, a potent peptide, protects against ischemic brain injury by activating the PI3K/Akt pathway.

    PubMed

    Gu, Qin; Zhai, Lijing; Feng, Xing; Chen, Jing; Miao, Zhigang; Ren, Liyan; Qian, Xuanchen; Yu, Jian; Li, Yan; Xu, Xingshun; Liu, Chun-Feng

    2013-11-01

    Apelin is an endogenous ligand of G protein-coupled receptor-apelin and angiotensin-1-like receptor (APJ). The biological effects of apelin-APJ system are reported in multiple systems including cardiovascular, endocrinal, and gastrointestinal system. Previous studies had shown that apelin-13 is a potential protective agent on cardiac ischemia; however, the role of apelin in the central nervous system remained unknown. In this study, we investigated therapeutic effects of apelin-36, a long form of apelin, in ischemic brain injury models. We found that apelin-36 reduced cerebral infarct volume in the middle cerebral artery occlusion (MCAO) model and the neonatal hypoxic/ischemic (H/I) injury model. Apelin-36 improved neurological deficits in the MCAO model and promoted long-term functional recovery after H/I brain injury. We further explored the protective mechanisms of apelin-36 on H/I brain injury. We clearly demonstrated that apelin-36 significantly reduced the levels of cleaved caspase-3 and Bax, two well-established apoptotic markers after H/I injury, indicating the anti-apoptotic activity of apelin-36 in ischemic injury. Since apelin-36 increased the level of phosphorylated Akt after H/I injury, we treated neonates with a specific PI3K inhibitor LY294002. We found that LY294002 decreased the phosphorylated Akt level and attenuated protective effects of apelin-36 on apoptosis. These suggested that the PI3K/Akt pathway was at least in part involved in the anti-apoptotic mechanisms of apelin-36. Our findings demonstrated that apelin-36 was a promising therapeutic agent on the treatment of ischemic brain injury.

  13. Tamoxifen inhibits tumor cell invasion and metastasis in mouse melanoma through suppression of PKC/MEK/ERK and PKC/PI3K/Akt pathways

    SciTech Connect

    Matsuoka, Hiroshi; Tsubaki, Masanobu; Yamazoe, Yuzuru; Ogaki, Mitsuhiko; Satou, Takao; Itoh, Tatsuki; Kusunoki, Takashi; Nishida, Shozo

    2009-07-15

    In melanoma, several signaling pathways are constitutively activated. Among these, the protein kinase C (PKC) signaling pathways are activated through multiple signal transduction molecules and appear to play major roles in melanoma progression. Recently, it has been reported that tamoxifen, an anti-estrogen reagent, inhibits PKC signaling in estrogen-negative and estrogen-independent cancer cell lines. Thus, we investigated whether tamoxifen inhibited tumor cell invasion and metastasis in mouse melanoma cell line B16BL6. Tamoxifen significantly inhibited lung metastasis, cell migration, and invasion at concentrations that did not show anti-proliferative effects on B16BL6 cells. Tamoxifen also inhibited the mRNA expressions and protein activities of matrix metalloproteinases (MMPs). Furthermore, tamoxifen suppressed phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt through the inhibition of PKC{alpha} and PKC{delta} phosphorylation. However, other signal transduction factor, such as p38 mitogen-activated protein kinase (p38MAPK) was unaffected. The results indicate that tamoxifen suppresses the PKC/mitogen-activated protein kinase kinase (MEK)/ERK and PKC/phosphatidylinositol-3 kinase (PI3K)/Akt pathways, thereby inhibiting B16BL6 cell migration, invasion, and metastasis. Moreover, tamoxifen markedly inhibited not only developing but also clinically evident metastasis. These findings suggest that tamoxifen has potential clinical applications for the treatment of tumor cell metastasis.

  14. Certain Diet and Lifestyle May Contribute to Islet β-cells Protection in Type-2 Diabetes via the Modulation of Cellular PI3K/AKT Pathway

    PubMed Central

    Kitagishi, Yasuko; Nakanishi, Atsuko; Minami, Akari; Asai, Yurina; Yasui, Mai; Iwaizako, Akiko; Suzuki, Miho; Ono, Yuna; Ogura, Yasunori; Matsuda, Satoru

    2014-01-01

    PI3K/AKT pathway has been shown to play a pivotal role on islet β-cell protection, enhancing β-cell survival by stimulating cell proliferation and inhibiting cell apoptosis. Accordingly, this pathway appears to be crucial in type-2 diabetes. Understanding the regulations of this pathway may provide a better efficacy of new therapeutic approaches. In this review, we summarize advances on the involvement of the PI3K/AKT pathway in hypothetical intra-cellular signaling of islet β-cells. As recent findings may show the nutritional regulation of the survival pathway in the islet β-cells through activation of the PI3K/AKT pathway, we also review studies on the features of several diets, correlated lifestyle, and its signaling pathway involved in type-2 diabetes. The molecular mechanisms contributing to the disease are the subject of considerable investigation, as a better understanding of the pathogenesis will lead to novel therapies against a condition of the disease. PMID:25400709

  15. Antitumor effect of manumycin on colorectal cancer cells by increasing the reactive oxygen species production and blocking PI3K-AKT pathway

    PubMed Central

    Zhang, Jingyu; Jiang, Hua; Xie, Li; Hu, Jing; Li, Li; Yang, Mi; Cheng, Lei; Liu, Baorui; Qian, Xiaoping

    2016-01-01

    Manumycin is a natural, well-tolerated microbial metabolite and is regarded as a farnesyltransferase inhibitor. Some data suggest that manumycin inhibits proliferation of diverse cancer cells through various pathways. However, the antitumor effect of manumycin on colorectal cancer (CRC) remains unknown. In the present study, we investigated the antitumor effect of manumycin on CRC in vitro and in vivo. The results of cell viability assay revealed that the proliferation of the CRC cells was significantly inhibited by manumycin. Moreover, cell apoptosis induced by manumycin was also found in a time- and dose-dependent manner. Interestingly, treatment of the CRC cells with manumycin resulted in increased generation of reactive oxygen species. Subsequently, manumycin also decreased the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and AKT, as well as the expression of caspase-9 and poly(ADP-ribose) polymerase (PARP) in a time-dependent manner. In addition, we found that N-acetyl-l-cysteine (NAC) attenuated the effect of manumycin on the PI3K-AKT pathway, and wortmannin reduced the effect of manumycin on caspase-9 and PARP expression. More importantly, the anticancer effect of manumycin was also observed in established tumor xenografts. Taken together, these findings supported the potential application of manumycin against colorectal carcinoma. PMID:27307747

  16. Inhibition of the PI3K/Akt/mTOR signaling pathway in diffuse large B-cell lymphoma: current knowledge and clinical significance.

    PubMed

    Majchrzak, Agata; Witkowska, Magdalena; Smolewski, Piotr

    2014-09-11

    Diffuse large B-cell lymphoma (DLBCL) is one of the most common non-Hodgkin lymphomas in adults. The disease is very heterogeneous in its presentation, that is DLBCL patients may differ from each other not only in regard to histology of tissue infiltration, clinical course or response to treatment, but also in respect to diversity in gene expression profiling. A growing body of knowledge on the biology of DLBCL, including abnormalities in intracellular signaling, has allowed the development of new treatment strategies, specifically directed against lymphoma cells. The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway plays an important role in controlling proliferation and survival of tumor cells in various types of malignancies, including DLBCL, and therefore it may be a promising target for therapeutic intervention. Currently, novel anticancer drugs are undergoing assessment in different phases of clinical trials in aggressive lymphomas, with promising outcomes. In this review we present a state of art review on various classes of small molecule inhibitors selectively involving PI3K/Akt/mTOR pathway and their clinical potential in this disease.

  17. Downregulation of PI3K/Akt/mTOR signaling pathway in curcumin-induced autophagy in APP/PS1 double transgenic mice.

    PubMed

    Wang, Chen; Zhang, Xiong; Teng, Zhipeng; Zhang, Tong; Li, Yu

    2014-10-01

    Autophagy is a lysosomal degradation pathway, which is essential for cell survival, proliferation, differentiation and homeostasis. It is well known that beta-amyloid (Aβ) aggregation is one of key characteristics for Alzheimer's disease (AD), which triggers a complex pathological cascade, leading to neurodegeneration. Recent studies have shown that Aβ peptide is generated from amyloid β precursor protein (APP) during autophagic turnover of APP-rich organelles by autophagy. Aβ generation during normal autophagy is subsequently degraded by lysosomes. Curcumin, a nature plant extraction, has been reported to inhibit the generation and deposition of Aβ; however, the underlying mechanisms are not fully understood yet. In the present study, we reported that curcumin treatment not only attenuated cognitive impairment detected by Morris water maze test, but also inhibited the generation of Aβ investigated by immunohistochemistry in APP/PS1 double transgenic AD mice. Moreover, curcumin induced autophagy in the mice, evidenced by LC3 immunofluorescence analysis and western blot assays on LC3. Furthermore, we found that curcumin significantly decreased the expression of Phosphatidylinositol 3-Kinase (PI3K), phosphorylated Akt and rapamycin (mTOR) at protein levels, respectively. Taken together, our data suggests that curcumin inhibits Aβ generation and induces of autophagy by downregulating PI3K/Akt/mTOR signaling pathway, and further shows a neuroprotective effect. Meanwhile curcumin might be a candidate neuroprotective agent for AD patients treatment by inducing autophagy.

  18. Low-dose testosterone alleviates vascular damage caused by castration in male rats in puberty via modulation of the PI3K/AKT signaling pathway

    PubMed Central

    Zhao, Jing; Liu, Ge-Li; Wei, Ying; Jiang, Li-Hong; Bao, Peng-Li; Yang, Qing-Yan

    2016-01-01

    The aim of the present study was to investigate the effect of testosterone on glucolipid metabolism and vascular injury in male rats, and examine the underlying molecular mechanisms. A total of 40 male Sprague-Dawley rats were divided into a control group (n=10), high-fat-diet + castration group (n=10), high-fat-diet + castration + low dose testosterone group (n=10), and high-fat-diet + castration + high dose testosterone group (n=10). Hematoxylin and eosin staining was performed to evaluate the morphology of the thoracic aortic tissues. Immunohistochemical staining was used to detect biomarkers of the phosphoinositide 3-kinase (PI3K) signaling pathway. The mRNA and protein expression levels of PI3K, AKT, insulin receptor substrate-1 (IRS-1), glucose transporter type 4 (GLUT-4), nuclear factor (NF)-κB and tumor necrosis factor (TNF)-α in the aortas were determined using quantitative polymerase chain reaction and Western blot analyses, respectively. Apoptosis in the aortic tissues was detected using a TUNEL assay. Castration induced apoptosis in the animals fed a high-fat-diet, whereas low dose testosterone replacement ameliorated the apoptosis in the aorta. However, the levels of apoptosis was more severe following high-dose testosterone treatment. Low-dose testosterone induced upregulation in the levels of IRS-1, AKT, GLUT-4 protein, NF-κB, TNF-α and PI3K, compared with those in the animals fed a high-fat diet following castration. A high dose of testosterone resulted in a significant decrease in the levels of IRS-1, AKT, GLUT-4, NF-κB, TNF-α and PI3K. Compared with the rats in the high-fat diet + castration group, a low dose of testosterone induced upregulation in the mRNA levels of IRS-1, AKT and GLUT-4, and downregulation of the mRNA levels of NF-κB, TNF-α and PI3K. A high dose of testosterone resulted in a significant decrease in the levels of IRS-1, AKT and GLUT-4, and marked increases in the mRNA levels of NF-κB, TNF-α and PI3K, compared with the

  19. Activation of RAF/MEK/ERK and PI3K/AKT/mTOR pathways in pituitary adenomas and their effects on downstream effectors.

    PubMed

    Dworakowska, D; Wlodek, E; Leontiou, C A; Igreja, S; Cakir, M; Teng, M; Prodromou, N; Góth, M I; Grozinsky-Glasberg, S; Gueorguiev, M; Kola, B; Korbonits, M; Grossman, A B

    2009-12-01

    Raf/MEK/ERK and phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) cascades are key signalling pathways interacting with each other to regulate cell growth and tumourigenesis. We have previously shown B-Raf and Akt overexpression and/or overactivation in pituitary adenomas. The aim of this study is to assess the expression of their downstream components (MEK1/2, ERK1/2, mTOR, TSC2, p70S6K) and effectors (c-MYC and CYCLIN D1). We studied tissue from 16 non-functioning pituitary adenomas (NFPAs), six GH-omas, six prolactinomas and six ACTH-omas, all collected at transsphenoidal surgery; 16 normal autopsy pituitaries were used as controls. The expression of phospho and total protein was assessed with western immunoblotting, and the mRNA expression with quantitative RT-PCR. The expression of pSer217/221 MEK1/2 and pThr183 ERK1/2 (but not total MEK1/2 or ERK1/2) was significantly higher in all tumour subtypes in comparison to normal pituitaries. There was no difference in the expression of phosphorylated/total mTOR, TSC2 or p70S6K between pituitary adenomas and controls. Neither c-MYC phosphorylation at Ser 62 nor total c-MYC was changed in the tumours. However, c-MYC phosphorylation at Thr58/Ser62 (a response target for Akt) was decreased in all tumour types. CYCLIN D1 expression was higher only in NFPAs. The mRNA expression of MEK1, MEK2, ERK1, ERK2, c-MYC and CCND1 was similar in all groups. Our data indicate that in pituitary adenomas both the Raf/MEK/ERK and PI3K/Akt/mTOR pathways are upregulated in their initial cascade, implicating a pro-proliferative signal derangement upstream to their point of convergence. However, we speculate that other processes, such as senescence, attenuate the changes downstream in these benign tumours. PMID:19620247

  20. Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis.

    PubMed

    Yang, Jung-Bo; Quan, Juan-Hua; Kim, Ye-Eun; Rhee, Yun-Ee; Kang, Byung-Hyun; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min; Lee, Young-Ha

    2015-08-01

    Trichomonas vaginalis; induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in TNF-α production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased TNF-α production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, TNF-α production was significantly decreased compared to the control; however, TNF-α reduction patterns were different depending on the type of PI3K/MAPK inhibitors. TNF-α production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of TNF-α production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.

  1. Involvement of IGF-1 and MEOX2 in PI3K/Akt1/2 and ERK1/2 pathways mediated proliferation and differentiation of perivascular adipocytes

    SciTech Connect

    Liu, Ping; Kong, Feng; Wang, Jue; Lu, Qinghua; Xu, Haijia; Qi, Tonggang; Meng, Juan

    2015-02-01

    Perivascular adipocyte (PVAC) proliferation and differentiation were closely involved in cardiovascular disease. We aimed to investigate whether phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways enhance PVAC functions activated by insulin-like growth factor 1(IGF-1) and suppressed by mesenchyme homeobox 2 (MEOX2). In this study, PVACs from primary culture were cultured and induced to differentiate. Cell viability assays demonstrated that IGF-1 promoted PVAC proliferation and differentiation. However MEOX2 counteracted these IGF-1-mediated actions. Flow Cytometry revealed that IGF-1 increased S phase cells and decreased apoptosis; however, MEOX2 decreased S phase cells, increased G0–G1 phase cells, and promoted apoptosis. During PVAC proliferation and differentiation, IGF-1 activated PI3K/Akt1/2 and ERK1/2 signaling pathways, upregulated the expression of these signaling proteins and FAS, and increased PVAC lipid content. In contrast, MEOX2 constrained the phosphorylation of ERK1/2 and Akt1/2 protein, down-regulated these signaling molecules and FAS, and decreased PVAC lipid content. Instead, MEOX2 knockdown enhanced the ERK1/2 and Akt1/2 phosphorylation, augmented the expression of these signaling molecules and FAS, and increased PVAC lipid content. Our findings suggested that PI3K/Akt1/2 and ERK1/2 activation mediated by IGF-1 is essential for PVAC proliferation and differentiation, and MEOX2 is a promising therapeutic gene to intervene in the signaling pathways and inhibit PVAC functions. - Highlights: • IGF-1 activated PI3K/Akt2 and ERK1/2 pathways to mediate PVAC proliferation and differentiation. • The expression of ERK1, ERK 2, PI3K, Akt1 and Akt2 showed different change trends between PVAC proliferation and differentiation. • MEOX2 effectively expressed in PVAC, increased early and late cellular apoptosis, and inhibited its proliferation. • MEOX2 depressed PVAC differentiation and FAS expression

  2. Momordin Ic couples apoptosis with autophagy in human hepatoblastoma cancer cells by reactive oxygen species (ROS)-mediated PI3K/Akt and MAPK signaling pathways.

    PubMed

    Mi, Yashi; Xiao, Chunxia; Du, Qingwei; Wu, Wanqiang; Qi, Guoyuan; Liu, Xuebo

    2016-01-01

    Momordin Ic is a principal saponin constituent of Fructus Kochiae, which acts as an edible and pharmaceutical product more than 2000 years in China. Our previous research found momordin Ic induced apoptosis by PI3K/Akt and MAPK signaling pathways in HepG2 cells. While the role of autophagy in momordin Ic induced cell death has not been discussed, and the connection between the apoptosis and autophagy is not clear yet. In this work, we reported momordin Ic promoted the formation of autophagic vacuole and expression of Beclin 1 and LC-3 in a dose- and time-dependent manner. Compared with momordin Ic treatment alone, the autophagy inhibitor 3-methyladenine (3-MA) also can inhibit apoptosis, while autophagy activator rapamycin (RAP) has the opposite effect, and the apoptosis inhibitor ZVAD-fmk also inhibited autophagy induced by momordin Ic. Momordin Ic simultaneously induces autophagy and apoptosis by suppressing the ROS-mediated PI3K/Akt and activating the ROS-related JNK and P38 pathways. Additionally, momordin Ic induces apoptosis by suppressing PI3K/Akt-dependent NF-κB pathways and promotes autophagy by ROS-mediated Erk signaling pathway. Those results suggest that momordin Ic has great potential as a nutritional preventive strategy in cancer therapy. PMID:26593748

  3. Diosgenin and 5-Methoxypsoralen Ameliorate Insulin Resistance through ER-α/PI3K/Akt-Signaling Pathways in HepG2 Cells.

    PubMed

    Fang, Ke; Dong, Hui; Jiang, Shujun; Li, Fen; Wang, Dingkun; Yang, Desen; Gong, Jing; Huang, Wenya; Lu, Fuer

    2016-01-01

    To determine the effects and the underlying mechanism of diosgenin (DSG) and 5-methoxypsoralen (5-MOP), two main active components in the classical Chinese prescription Hu-Lu-Ba-Wan (HLBW), on insulin resistance, HepG2 cells were incubated in medium containing insulin. Treatments with DSG, 5-MOP, and their combination were performed, respectively. The result showed that the incubation of HepG2 cells with high concentration insulin markedly decreased glucose consumption and glycogen synthesis. However, treatment with DSG, 5-MOP, or their combination significantly reversed the condition and increased the phosphorylated expression of estrogen receptor-α (ERα), sarcoma (Src), Akt/protein kinase B, glycogen synthase kinase-3β (GSK-3β), and the p85 regulatory subunit of phosphatidylinositol 3-kinase p85 (PI3Kp85). At the transcriptional level, expression of the genes mentioned above also increased except for the negative regulation of GSK-3β mRNA. The increased expression of glucose transport-4 (GLUT-4) was meanwhile observed through immunofluorescence. Nevertheless, the synergistic effect of DSG and 5-MOP on improving glycometabolism was not obvious in the present study. These results suggested that DSG and 5-MOP may improve insulin resistance through an ER-mediated PI3K/Akt activation pathway which may be a new strategy for type 2 diabetes mellitus, especially for women in an estrogen-deficient condition. PMID:27656241

  4. The Neuroprotection of Liraglutide Against Ischaemia-induced Apoptosis through the Activation of the PI3K/AKT and MAPK Pathways

    PubMed Central

    Zhu, Huili; Zhang, Yusheng; Shi, Zhongshan; Lu, Dan; Li, Tingting; Ding, Yan; Ruan, Yiwen; Xu, Anding

    2016-01-01

    Glucagon-like peptide-1 (GLP-1) is an incretin hormone that increases glucose-dependent insulin secretion to reduce the glucose level. Liraglutide, a long-acting GLP-1 analogue, has been found to have neuroprotective action in various experimental models. However, the protective mechanisms of liraglutide in ischaemic stroke remain unclear. Here, we demonstrated that liraglutide significantly decreased the infarct volume, improved neurologic deficits, and lowered stress-related hyperglycaemia without causing hypoglycaemia in a rat model of middle cerebral artery occlusion (MCAO). Liraglutide inhibited cell apoptosis by reducing excessive reactive oxygen species (ROS) and improving the function of mitochondria in neurons under oxygen glucose deprivation (OGD) in vitro and MCAO in vivo. Liraglutide up-regulated the phosphorylation of protein kinase B (AKT) and extracellular signal-regulated kinases (ERK) and inhibited the phosphorylation of c-jun-NH2-terminal kinase (JNK) and p38. Moreover, the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and/or the ERK inhibitor U0126 counteracted the protective effect of liraglutide. Taken together, these results suggest that liraglutide exerts neuroprotective action against ischaemia-induced apoptosis through the reduction of ROS and the activation of the PI3K/AKT and mitogen-activated protein kinase (MAPK) pathways. Therefore, liraglutide has therapeutic potential for patients with ischaemic stroke, especially those with Type 2 diabetes mellitus or stress hyperglycaemia. PMID:27240461

  5. Activation of Robo1 signaling of breast cancer cells by Slit2 from stromal fibroblast restrains tumorigenesis via blocking PI3K/Akt/β-catenin pathway.

    PubMed

    Chang, Po-Hao; Hwang-Verslues, Wendy W; Chang, Yi-Cheng; Chen, Chun-Chin; Hsiao, Michael; Jeng, Yung-Ming; Chang, King-Jen; Lee, Eva Y-H P; Shew, Jin-Yuh; Lee, Wen-Hwa

    2012-09-15

    Tumor microenvironment plays a critical role in regulating tumor progression by secreting factors that mediate cancer cell growth. Stromal fibroblasts can promote tumor growth through paracrine factors; however, restraint of malignant carcinoma progression by the microenvironment also has been observed. The mechanisms that underlie this paradox remain unknown. Here, we report that the tumorigenic potential of breast cancer cells is determined by an interaction between the Robo1 receptor and its ligand Slit2, which is secreted by stromal fibroblasts. The presence of an active Slit2/Robo1 signal blocks the translocation of β-catenin into nucleus, leading to downregulation of c-myc and cyclin D1 via the phosphoinositide 3-kinase (PI3K)/Akt pathway. Clinically, high Robo1 expression in the breast cancer cells correlates with increased survival in patients with breast cancer, and low Slit2 expression in the stromal fibroblasts is associated with lymph node metastasis. Together, our findings explain how a specific tumor microenvironment can restrain a given type of cancer cell from progression and show that both stromal fibroblasts and tumor cell heterogeneity affect breast cancer outcomes.

  6. miR-16 targets fibroblast growth factor 2 to inhibit NPC cell proliferation and invasion via PI3K/AKT and MAPK signaling pathways

    PubMed Central

    Li, Yingqin; Tang, Xinran; Wen, Xin; Yang, Xiaojing; Zhang, Jian; Wang, Yaqin; Ma, Jun; Liu, Na

    2016-01-01

    Dysregulation of miRNAs has been shown to contribute to the carcinogenesis and progression of nasopharyngeal carcinoma (NPC). Our previous microarray data showed that miR-16 expression is significantly decreased in archived NPC tissues. Here, we confirmed that miR-16 was reduced in NPC cell lines and freshly-frozen samples. Ectopic expression of miR-16 suppressed NPC cell proliferation, migration, and invasion in vitro and inhibited tumor growth and metastatic colonization in the lung in vivo. Furthermore, fibroblast growth factor 2 (FGF2) was identified as a direct target of miR-16, and both phosphoinositide-3- kinase/AKT (PI3K/AKT) and mitogen-activated protein kinase (MAPK) signaling pathways were repressed after miR-16 overexpression. In addition, the restoration of FGF2 reversed the suppressive effects of miR-16. Together, these results indicated that miR-16 suppresses NPC carcinogenesis and progression by targeting FGF2, thereby representing a potential target for miRNA-based therapy for NPC in the future. PMID:26655091

  7. The molecular mechanism of polygalasaponin F-mediated decreases in TNFα: emphasizing the role of the TLR4-PI3K/AKT-NF-κB pathway.

    PubMed

    Yan, Wen-Fen; Shao, Qian-Hang; Zhang, Dong-Ming; Yuan, Yu-He; Chen, Nai-Hong

    2015-01-01

    Polygalasaponin F (PS-F), an oleanane-type triterpenoid saponin extracted from Polygala japonica, decreases the release of the inflammatory cytokine tumor necrosis factor α (TNFα), but the precise molecular mechanisms by which this event occurs are not fully understood. To study the anti-neuroinflammatory mechanisms of PS-F, enzyme-linked immunosorbent assay was used to detect the secretion of TNFα from BV-2 microglial cells. Nuclear proteins extracted from BV-2 microglial cells stimulated by lipopolysaccharide (LPS) and pretreated with/without inhibitors were measured by Western blotting, and cell viability was evaluated by MTT analysis. The results indicated that inhibition of toll-like receptor (TLR) 4 (CLI-095 1 μg/ml), phosphatidylinositol 3-kinase (PI3K) (Ly294002 10 μM) or IκBα phosphorylation (Bay11-7082 10 μM) completely prevents the release of TNFα induced by LPS without affecting cell viability and attenuated the nuclear translocation of p65 stimulated by LPS. In addition, PS-F exhibited a similar trend regarding TNFα release, AKT phosphorylation and NF-κB translocation. These results suggest that PS-F reduces neuroinflammatory cytokine secretion through the regulation of the TLR4-PI3K/AKT-NF-κB signaling pathway. PMID:26235355

  8. Diosgenin and 5-Methoxypsoralen Ameliorate Insulin Resistance through ER-α/PI3K/Akt-Signaling Pathways in HepG2 Cells

    PubMed Central

    Dong, Hui; Jiang, Shujun; Li, Fen; Wang, Dingkun; Yang, Desen; Gong, Jing; Huang, Wenya

    2016-01-01

    To determine the effects and the underlying mechanism of diosgenin (DSG) and 5-methoxypsoralen (5-MOP), two main active components in the classical Chinese prescription Hu-Lu-Ba-Wan (HLBW), on insulin resistance, HepG2 cells were incubated in medium containing insulin. Treatments with DSG, 5-MOP, and their combination were performed, respectively. The result showed that the incubation of HepG2 cells with high concentration insulin markedly decreased glucose consumption and glycogen synthesis. However, treatment with DSG, 5-MOP, or their combination significantly reversed the condition and increased the phosphorylated expression of estrogen receptor-α (ERα), sarcoma (Src), Akt/protein kinase B, glycogen synthase kinase-3β (GSK-3β), and the p85 regulatory subunit of phosphatidylinositol 3-kinase p85 (PI3Kp85). At the transcriptional level, expression of the genes mentioned above also increased except for the negative regulation of GSK-3β mRNA. The increased expression of glucose transport-4 (GLUT-4) was meanwhile observed through immunofluorescence. Nevertheless, the synergistic effect of DSG and 5-MOP on improving glycometabolism was not obvious in the present study. These results suggested that DSG and 5-MOP may improve insulin resistance through an ER-mediated PI3K/Akt activation pathway which may be a new strategy for type 2 diabetes mellitus, especially for women in an estrogen-deficient condition.

  9. Sanguinarine Induces Apoptosis of Human Oral Squamous Cell Carcinoma KB Cells via Inactivation of the PI3K/Akt Signaling Pathway.

    PubMed

    Lee, Tae Kyung; Park, Cheol; Jeong, Soon-Jeong; Jeong, Moon-Jin; Kim, Gi-Young; Kim, Wun-Jae; Choi, Yung Hyun

    2016-08-01

    Preclinical Research Sanguinarine, an alkaloid isolated from the root of Sanguinaria canadensis and other plants of the Papaveraceae family, selectively induces apoptotic cell death in a variety of human cancer cells, but its mechanism of action requires further elaboration. The present study investigated the pro-apoptotic effects of sanguinarine in human oral squamous cell carcinoma KB cells. Sanguinarine treatment increased DR5/TRAILR2 (death receptor 5/TRAIL receptor 2) expression and enhanced the activation of caspase-8 and cleavage of its substrate, Bid. Sanguinarine also induced the mitochondrial translocation of pro-apoptotic Bax, mitochondrial dysfunction, cytochrome c release to the cytosol, and activation of caspase-9 and -3. However, a pan-caspase inhibitor, z-VAD-fmk, reversed the growth inhibition and apoptosis induced by sanguinarine. Sanguinarine also suppressed the phosphorylation of phosphoinositide 3-kinase (PI3K) and Akt in KB cells, while co-treatment of cells with sanguinarine and a PI3K inhibitor revealed synergistic apoptotic effects. However, pharmacological inhibition of AMP-activated protein kinase and mitogen-activated protein kinases did not reduce or enhance sanguinarine-induced growth inhibition and apoptosis. Collectively, these findings indicate that the pro-apoptotic effects of sanguinarine in KB cells may be regulated by a caspase-dependent cascade via activation of both intrinsic and extrinsic signaling pathways and inactivation of PI3K/Akt signaling. Drug Dev Res 77 : 227-240, 2016.   © 2016 Wiley Periodicals, Inc.

  10. The molecular mechanism of polygalasaponin F-mediated decreases in TNFα: emphasizing the role of the TLR4-PI3K/AKT-NF-κB pathway.

    PubMed

    Yan, Wen-Fen; Shao, Qian-Hang; Zhang, Dong-Ming; Yuan, Yu-He; Chen, Nai-Hong

    2015-01-01

    Polygalasaponin F (PS-F), an oleanane-type triterpenoid saponin extracted from Polygala japonica, decreases the release of the inflammatory cytokine tumor necrosis factor α (TNFα), but the precise molecular mechanisms by which this event occurs are not fully understood. To study the anti-neuroinflammatory mechanisms of PS-F, enzyme-linked immunosorbent assay was used to detect the secretion of TNFα from BV-2 microglial cells. Nuclear proteins extracted from BV-2 microglial cells stimulated by lipopolysaccharide (LPS) and pretreated with/without inhibitors were measured by Western blotting, and cell viability was evaluated by MTT analysis. The results indicated that inhibition of toll-like receptor (TLR) 4 (CLI-095 1 μg/ml), phosphatidylinositol 3-kinase (PI3K) (Ly294002 10 μM) or IκBα phosphorylation (Bay11-7082 10 μM) completely prevents the release of TNFα induced by LPS without affecting cell viability and attenuated the nuclear translocation of p65 stimulated by LPS. In addition, PS-F exhibited a similar trend regarding TNFα release, AKT phosphorylation and NF-κB translocation. These results suggest that PS-F reduces neuroinflammatory cytokine secretion through the regulation of the TLR4-PI3K/AKT-NF-κB signaling pathway.

  11. Diosgenin and 5-Methoxypsoralen Ameliorate Insulin Resistance through ER-α/PI3K/Akt-Signaling Pathways in HepG2 Cells

    PubMed Central

    Dong, Hui; Jiang, Shujun; Li, Fen; Wang, Dingkun; Yang, Desen; Gong, Jing; Huang, Wenya

    2016-01-01

    To determine the effects and the underlying mechanism of diosgenin (DSG) and 5-methoxypsoralen (5-MOP), two main active components in the classical Chinese prescription Hu-Lu-Ba-Wan (HLBW), on insulin resistance, HepG2 cells were incubated in medium containing insulin. Treatments with DSG, 5-MOP, and their combination were performed, respectively. The result showed that the incubation of HepG2 cells with high concentration insulin markedly decreased glucose consumption and glycogen synthesis. However, treatment with DSG, 5-MOP, or their combination significantly reversed the condition and increased the phosphorylated expression of estrogen receptor-α (ERα), sarcoma (Src), Akt/protein kinase B, glycogen synthase kinase-3β (GSK-3β), and the p85 regulatory subunit of phosphatidylinositol 3-kinase p85 (PI3Kp85). At the transcriptional level, expression of the genes mentioned above also increased except for the negative regulation of GSK-3β mRNA. The increased expression of glucose transport-4 (GLUT-4) was meanwhile observed through immunofluorescence. Nevertheless, the synergistic effect of DSG and 5-MOP on improving glycometabolism was not obvious in the present study. These results suggested that DSG and 5-MOP may improve insulin resistance through an ER-mediated PI3K/Akt activation pathway which may be a new strategy for type 2 diabetes mellitus, especially for women in an estrogen-deficient condition. PMID:27656241

  12. Alpha-chaconine-reduced metastasis involves a PI3K/Akt signaling pathway with downregulation of NF-kappaB in human lung adenocarcinoma A549 cells.

    PubMed

    Shih, Yuan-Wei; Chen, Pin-Shern; Wu, Cheng-Hsun; Jeng, Ya-Fang; Wang, Chau-Jong

    2007-12-26

    Alpha-chaconine, isolated from Solanum tuberosum Linn., is a naturally occurring steroidal glycoalkaloid in potato sprouts. Some reports demonstrated that alpha-chaconine had various anticarcinogenic properties. The aim of this study is to investigate the inhibitory effect of alpha-chaconine on lung adenocarcinoma cell metastasis in vitro. We chose the highly metastatic A549 cells, which were treated with various concentrations of alpha-chaconine to clarify the potential of inhibiting A549 cells invasion and migration. Data showed that alpha-chaconine inhibited A549 cell invasion/migration according to wound healing assay and Boyden chamber assay. Our results also showed that alpha-chaconine could inhibit phosphorylation of c-Jun N-terminal kinase (JNK) and Akt, whereas it did not affected phosphorylation of extracellular signal regulating kinase (ERK) and p38. In addition, alpha-chaconine significantly decreased the nuclear level of nuclear factor kappa B (NF-kappaB) and the binding ability of NF-kappaB. These results suggested that alpha-chaconine inhibited A549 cell metastasis by a reduction of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) activities involving suppression of phosphoinositide 3-kinase/Akt/NF-kappaB (PI3K/Akt/NF-kappaB) signaling pathway. Inhibiting metastasis by alpha-chaconine might offer a pivotal mechanism for its effective chemotherapeutic action.

  13. Feedbacks and adaptive capabilities of the PI3K/Akt/mTOR axis in acute myeloid leukemia revealed by pathway selective inhibition and phosphoproteome analysis.

    PubMed

    Bertacchini, J; Guida, M; Accordi, B; Mediani, L; Martelli, A M; Barozzi, P; Petricoin, E; Liotta, L; Milani, G; Giordan, M; Luppi, M; Forghieri, F; De Pol, A; Cocco, L; Basso, G; Marmiroli, S

    2014-11-01

    Acute myeloid leukemia (AML) primary cells express high levels of phosphorylated Akt, a master regulator of cellular functions regarded as a promising drug target. By means of reverse phase protein arrays, we examined the response of 80 samples of primary cells from AML patients to selective inhibitors of the phosphatidylinositol 3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) axis. We confirm that >60% of the samples analyzed are characterized by high pathway phosphorylation. Unexpectedly, however, we show here that targeting Akt and mTOR with the specific inhibitors Akti 1/2 and Torin1, alone or in combination, result in paradoxical Akt phosphorylation and activation of downstream signaling in 70% of the samples. Indeed, we demonstrate that cropping Akt or mTOR activity can stabilize the Akt/mTOR downstream effectors Forkhead box O and insulin receptor substrate-1, which in turn potentiate signaling through upregulation of the expression/phosphorylation of selected growth factor receptor tyrosine kinases (RTKs). Activation of RTKs in turn reactivates PI3K and downstream signaling, thus overruling the action of the drugs. We finally demonstrate that dual inhibition of Akt and RTKs displays strong synergistic cytotoxic effects in AML cells and downmodulates Akt signaling to a much greater extent than either drug alone, and should therefore be explored in AML clinical setting.

  14. Hypoglycemic effect of D-chiro-inositol in type 2 diabetes mellitus rats through the PI3K/Akt signaling pathway.

    PubMed

    Gao, Yun-Feng; Zhang, Meng-Na; Wang, Tian-Xin; Wu, Tian-Chen; Ai, Ru-Dan; Zhang, Ze-Sheng

    2016-09-15

    In this investigation, a model of type 2 diabetes mellitus (T2DM) was used on Sprague-Dawley (SD) rats to clarify more details of the mechanism in the therapy of T2DM. D-chiro-inositol (DCI) was administrated to the diabetic rats as two doses [30, 60 mg/(kg·body weight·day)]. The biochemical indices revealed that DCI had a positive effect on hypoglycemic activity and promoted the glycogen synthesis. The rats in DCI high-dosage group had a blood glucose reduction rate of 21.5% after 5 weeks of treatment, and had insulin content in serum about 15.3 ± 2.37 mIU/L which was significantly decreased than diabetes control group. Real-time polymerase chain reaction (RT-PCR) results revealed that DCI gave a positive regulation on glycogen synthase (GS) and protein glucose transporter-4 (Glut4). Western blotting suggested that DCI could up-regulated the expression of the phosphatidylinositol-3-kinase (PI3K) p85, PI3Kp110, GS as well as the phosphorylation of protein kinase B (Akt) both in the liver and the skeletal muscle. The results also revealed that DCI enhanced the Glut4 expression on skeletal muscle. Above all, DCI played a positive role in regulating insulin-mediated glucose uptake through the PI3K/Akt signaling pathway in T2DM rats.

  15. PI3K/Akt signaling pathway triggers P2X7 receptor expression as a pro-survival factor of neuroblastoma cells under limiting growth conditions

    PubMed Central

    Gómez-Villafuertes, Rosa; García-Huerta, Paula; Díaz-Hernández, Juan Ignacio; Miras-Portugal, Mª Teresa

    2015-01-01

    The expression of purinergic P2X7 receptor (P2X7R) in neuroblastoma cells is associated to accelerated growth rate, angiogenesis, metastasis and poor prognosis. Noticeably, P2X7R allows the survival of neuroblastoma cells under restrictive conditions, including serum and glucose deprivation. Previously we identified specificity protein 1 (Sp1) as the main factor involved in the transcriptional regulation of P2rx7 gene, reporting that serum withdrawal triggers the expression of P2X7R in Neuro-2a (N2a) neuroblastoma cell line. Here we demonstrate that PI3K/Akt pathway is crucial for the upregulation of P2X7R expression in serum-deprived neuroblastoma cells, circumstance that facilitates cell proliferation in the absence of trophic support. The effect exerted by PI3K/Akt is independent of both mTOR and GSK3, but requires the activation of EGF receptor (EGFR). Nuclear levels of Sp1 are strongly reduced by inhibition of PI3K/Akt pathway, and blockade of Sp1-dependent transcription with mithramycin A prevents upregulation of P2rx7 gene expression following serum withdrawal. Furthermore, atypical PKCζ plays a key role in the regulation of P2X7R expression by preventing phosphorylation and, consequently, activation of Akt. Altogether, these data indicate that activation of EGFR enhanced the expression of P2X7R in neuroblastoma cells lacking trophic support, being PI3K/Akt/PKCζ signaling pathway and Sp1 mediating this pro-survival outcome. PMID:26687764

  16. Tetramethylpyrazine induces SH-SY5Y cell differentiation toward the neuronal phenotype through activation of the PI3K/Akt/Sp1/TopoIIβ pathway.

    PubMed

    Yan, Yong-Xin; Zhao, Jun-Xia; Han, Shuo; Zhou, Na-Jing; Jia, Zhi-Qiang; Yao, Sheng-Jie; Cao, Cui-Li; Wang, Yan-Ling; Xu, Yan-Nan; Zhao, Juan; Yan, Yun-Li; Cui, Hui-Xian

    2015-12-01

    Tetramethylpyrazine (TMP) is an active compound extracted from the traditional Chinese medicinal herb Chuanxiong. Previously, we have shown that TMP induces human SH-SY5Y neuroblastoma cell differentiation toward the neuronal phenotype by targeting topoisomeraseIIβ (TopoIIβ), a protein implicated in neural development. In the present study, we aimed to elucidate whether the transcriptional factors specificity protein 1 (Sp1) and nuclear factor Y (NF-Y), in addition to the upstream signaling pathways ERK1/2 and PI3K/Akt, are involved in modulating TopoIIβ expression in the neuronal differentiation process. We demonstrated that SH-SY5Y cells treated with TMP (80μM) terminally differentiated into neurons, characterized by increased neuronal markers, tubulin βIII and microtubule associated protein 2 (MAP2), and increased neurite outgrowth, with no negative effect on cell survival. TMP also increased the expression of TopoIIβ, which was accompanied by increased expression of Sp1 in the differentiated neuron-like cells, whereas NF-Y protein levels remained unchanged following the differentiation progression. We also found that the phosphorylation level of Akt, but not ERK1/2, was significantly increased as a result of TMP stimulation. Furthermore, as established by chromatin immunoprecipitation (ChIP) assay, activation of the PI3K/Akt pathway increased Sp1 binding to the promoter of the TopoIIβ gene. Blockage of PI3K/Akt was shown to lead to subsequent inhibition of TopoIIβ expression and neuronal differentiation. Collectively, the results indicate that the PI3K/Akt/Sp1/TopoIIβ signaling pathway is necessary for TMP-induced neuronal differentiation. Our findings offer mechanistic insights into understanding the upstream regulation of TopoIIβ in neuronal differentiation, and suggest potential applications of TMP both in neuroscience research and clinical practice to treat relevant diseases of the nervous system. PMID:26518113

  17. Pramipexole-Induced Hypothermia Reduces Early Brain Injury via PI3K/AKT/GSK3β pathway in Subarachnoid Hemorrhage rats

    PubMed Central

    Ma, Junwei; Wang, Zhong; Liu, Chenglin; Shen, Haitao; Chen, Zhouqing; Yin, Jia; Zuo, Gang; Duan, Xiaochun; Li, Haiying; Chen, Gang

    2016-01-01

    Previous studies have shown neuroprotective effects of hypothermia. However, its effects on subarachnoid hemorrhage (SAH)-induced early brain injury (EBI) remain unclear. In this study, a SAH rat model was employed to study the effects and mechanisms of pramipexole-induced hypothermia on EBI after SAH. Dose-response experiments were performed to select the appropriate pramipexole concentration and frequency of administration for induction of mild hypothermia (33–36 °C). Western blot, neurobehavioral evaluation, Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Fluoro-Jade B (FJB) staining were used to detect the effects of pramipexole-induced hypothermia on SAH-induced EBI, as well as to study whether controlled rewarming could attenuate these effects. Inhibitors targeting the PI3K/AKT/GSK3β pathway were administered to determine whether the neuroprotective effect of pramipexole-induced hypothermia was mediated by PI3K/AKT/GSK3β signaling pathway. The results showed that intraperitoneal injection of pramipexole at 0.25 mg/kg body weight once per 8 hours was found to successfully and safely maintain rats at mild hypothermia. Pramipexole-induced hypothermia ameliorated SAH-induced brain cell death, blood-brain barrier damage and neurobehavioral deficits in a PI3K/AKT/GSK3β signaling-dependent manner. Therefore, we may conclude that pramipexole-induced hypothermia could effectively inhibit EBI after SAH in rats via PI3K/AKT/GSK3β signaling pathway. PMID:27026509

  18. Functional interdependence at the chromatin level between the MKK6/p38 and IGF1/Pi3K/AKT pathways during muscle differentiation

    PubMed Central

    Carlo, Serra; Daniela, Palacios; Chiara, Mozzetta; Sonia, Forcales; Ianessa, Morantte; Meri, Ripani; Jones David, R.; Keyong, Du; Jhala Ulupi, S.; Cristiano, Simone; Lorenzo, Puri Pier

    2009-01-01

    During muscle regeneration, the mechanism integrating environmental cues at the chromatin of muscle progenitors is unknown. We show that inflammation-activated MKK6-p38 and IGF1-induced Pi3K/AKT pathways converge on the chromatin of muscle genes to target distinct components of the muscle transcriptosome. p38 α/β kinases recruit the SWI/SNF chromatin-remodeling complex; AKT 1 and 2 promote the association of MyoD with p300 and PCAF acetyltransferases, via direct phosphorylation of p300. Pharmacological or genetic interference with either pathway led to partial assembly of discrete chromatin-bound complexes, which reflected two reversible and distinct cellular phenotypes. Remarkably, Pi3K/AKT blockade was permissive for chromatin recruitment of MEF2-SWI/SNF complex, whose remodeling activity was compromised in the absence of MyoD and acetyltransferases. The functional interdependence between p38 and IGF1/Pi3K/AKT pathways was further established by the evidence that blockade of AKT chromatin targets was sufficient to prevent the activation of the myogenic program triggered by deliberate activation of p38 signaling PMID:17964260

  19. Tris(2-chloroethyl)phosphate-induced cell growth arrest via attenuation of SIRT1-independent PI3K/Akt/mTOR pathway.

    PubMed

    Zhang, Wenjuan; Zhang, Youjian; Wang, Zhiyuan; Xu, Tian; Huang, Cheng; Yin, Wenjun; Wang, Jing; Xiong, Wei; Lu, Wenhong; Zheng, Hongyan; Yuan, Jing

    2016-07-01

    Tris(2-chloroethyl)phosphate (TCEP) as an organophosphorus flame retardant and plasticizer has been widely used in industrial and household products. It not only was detected in residential indoor air and dust, surface and drinking water, but also in human plasma and breast milk, and tissue samples of liver, kidneys and brain from rodents. TCEP is classified as carcinogenic category 2 and toxic for reproduction category 1B. Sufficient evidence from experimental animals indicated carcinogenicity of TCEP in the liver, and kidneys as well as cell loss in the brain. However, the underlying mechanisms of TCEP-induced hepatotoxicity are mostly unknown. We investigated the in vitro effects of TCEP as well as TCEP-induced cell growth in the L02 and HepG2 cells through the PI3K/Akt/mTOR pathway. We found that TCEP reduced cell viability of these cell lines, induced the cell growth arrest, upregulated mRNA and protein levels of SIRT1, and attenuated the PI3K/Akt/mTOR pathway. However, growth arrest of the L02 and HepG2 cells were aggravated after inhibiting the SIRT1 expression with EX-527. The findings above suggested that TCEP induced the cell growth arrest of L02 and HepG2 cells via attenuation of the SIRT1-independent PI3K/Akt/mTOR pathway. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26378621

  20. Inhibition of PI3K/Akt Pathway Impairs G2/M Transition of Cell Cycle in Late Developing Progenitors of the Avian Embryo Retina

    PubMed Central

    Ornelas, Isis Moraes; Silva, Thayane Martins; Fragel-Madeira, Lucianne; Ventura, Ana Lucia Marques

    2013-01-01

    PI3K/Akt is an important pathway implicated in the proliferation and survival of cells in the CNS. Here we investigated the participation of the PI3K/Akt signal pathway in cell cycle of developing retinal progenitors. Immunofluorescence assays performed in cultures of chick embryo retinal cells and intact tissues revealed the presence of phosphorylated Akt and 4E-BP1 in cells with typical mitotic profiles. Blockade of PI3K activity with the chemical inhibitor LY 294002 (LY) in retinal explants blocked the progression of proliferating cells through G2/M transition, indicated by an expressive increase in the number of cells labeled for phosphorylated histone H3 in the ventricular margin of the retina. No significant level of cell death could be detected at this region. Retinal explants treated with LY for 24 h also showed a significant decrease in the expression of phospho-Akt, phospho-GSK-3 and the hyperphosphorylated form of 4E-BP1. Although no change in the expression of cyclin B1 was detected, a significant decrease in CDK1 expression was noticed after 24 h of LY treatment both in retinal explants and monolayer cultures. Our results suggest that PI3K/Akt is an active pathway during proliferation of retinal progenitors and its activity appears to be required for proper CDK1 expression levels and mitosis progression of these cells. PMID:23301080

  1. Genetic variants in PI3K/AKT pathway are associated with severe radiation pneumonitis in lung cancer patients treated with radiation therapy.

    PubMed

    Tang, Yang; Liu, Bo; Li, Jing; Wu, Huanlei; Yang, Ju; Zhou, Xiao; Yi, Mingxiao; Li, Qianxia; Yu, Shiying; Yuan, Xianglin

    2016-01-01

    PI3K/AKT pathway plays important roles in inflammatory and fibrotic diseases while its connection to radiation pneumonitis (RP) is unclear. In this study, we explored the associations of genetic variants in PI3K/AKT pathway with RP in lung cancer patients with radiotherapy. Two hundred and sixty one lung cancer patients with radiotherapy were included in this prospective study (NCT02490319) and genotyped by MassArray and Sanger Sequence methods. By multivariate Cox hazard analysis and multiple testing, GA/GG genotype of AKT2: rs33933140 (HR = 0.272, 95% CI: 0.140-0.530, P = 1.3E-4, Pc = 9.1E-4), and the GT/GG genotype of PI3CA: rs9838117 (HR = 0.132, 95% CI: 0.042-0.416, P = 0.001, Pc = 0.006) were found to be strongly associated with a decreased occurrence of RP ≥ grade 3. And patients with the CT/TT genotype of AKT2: rs11880261 had a notably higher incidence of RP ≥ grade 3 (HR = 2.950, 95% CI: 1.380-6.305, P = 0.005, Pc = 0.025). We concluded that the genetic variants of PI3K/AKT pathway were significantly related to RP of grade ≥ 3 and may thus be predictors of severe RP before radiotherapy, if further validated in larger population.

  2. Induction of Multidrug Resistance of Acute Myeloid Leukemia Cells by Cocultured Stromal Cells via Upregulation of the PI3K/Akt Signaling Pathway.

    PubMed

    Chen, Ping; Jin, Qing; Fu, Qiang; You, Peidong; Jiang, Xi; Yuan, Qin; Huang, Huifang

    2016-01-01

    This study aimed to investigate the role of the PI3K/Akt signaling pathway in multidrug resistance of acute myeloid leukemia (AML) cells induced by cocultured stromal cells. Human AML cell lines HL-60 and U937 were adhesion cocultured with human bone marrow stromal cell line HS-5 cells. Such coculturing induced HL-60 and U937 cells resistant to chemotherapeutic drugs including daunorubicin (DNR), homoharringtonine (HHT), and cytosine arabinoside (Ara-C). The coculturing-induced resistance of AML cells to DNR, HHT, and Ara-C can be partially reversed by inhibition of the PI3K/Akt signaling pathway. Clinically, AML patients with a low level of PTEN and a high level of CCND1 had high relapse rates within 1 year, and newly diagnosed AML patients with extramedullary infiltration had a low level of PTEN. This study confirms the involvement of the PI3K/Akt signaling pathway in multidrug resistance in AML cells induced by stroma and suggests that the expression of PTEN and CCND1 may be a prognostic indicator for AML. PMID:27656831

  3. Fra-1 is upregulated in gastric cancer tissues and affects the PI3K/Akt and p53 signaling pathway in gastric cancer.

    PubMed

    He, Junyu; Zhu, Guangchao; Gao, Lu; Chen, Pan; Long, Yuehua; Liao, Shan; Yi, Hong; Yi, Wei; Pei, Zhen; Wu, Minghua; Li, Xiaoling; Xiang, Juanjuan; Peng, Shuping; Ma, Jian; Zhou, Ming; Xiong, Wei; Zeng, Zhaoyang; Xiang, Bo; Tang, Ke; Cao, Li; Li, Guiyuan; Zhou, Yanhong

    2015-11-01

    Gastric cancer is an aggressive disease that continues to have a daunting impact on global health. Fra-1 (FOSL1) plays important roles in oncogenesis in various malignancies. We investigated the expression of Fra-1 in gastric cancer (GC) tissues by qPCR, immunohistochemistry (IHC) and western blot technologies. The results showed that Fra-1 was overexpressed in gastric cancer tissues compared with the adjacent non‑cancerous tissues. To explore the possible mechanism of Fra-1 in GC, we elucidated the effect of Fra-1 in the apoptosis and cell cycle of gastric cancer cells, AGS, and found that a considerable decrease in apoptotic cells and increase of S phase rate were observed for AGS cells with Fra-1 overexpession. We identified and confirmed that Fra-1 affected the expression level of CTTN and EZR in vitro through LC-MS/MS analyses and western blot technology. Furthermore, we found that Fra-1 was correlated with dysregulation PI3K/Akt and p53 signaling pathway in gastric cancer tissues in vitro. Moreover, we found that Fra-1 overexpression affected the expression of PI3K, Akt, MDM2 and p53 in vivo. In summary, our results suggest that Fra-1 is upregulated in gastric cancer tissues and plays its function by affecting the PI3K/Akt and p53 signaling pathway in gastric cancer.

  4. RLIP76-dependent suppression of PI3K/AKT/Bcl-2 pathway by miR-101 induces apoptosis in prostate cancer

    SciTech Connect

    Yang, Jing; Song, Qi; Cai, Yi; Wang, Peng; Wang, Min; Zhang, Dong

    2015-08-07

    MicroRNA-101 (miR-101) participates in carcinogenesis and tumor progression in various cancers. However, its biological functions in prostate cancer are still unclear. Here, we demonstrate that miR-101 represents a critical role in regulating cell apoptosis in prostate cancer cells. We first demonstrated that miR-101 treatment promoted apoptosis in DU145 and PC3 cells by using flow cytometric analysis and transmission electron microscopy (TEM). To verify the mechanisms, we identified a novel miR-101 target, Ral binding protein 1 (RLIP76). We found miR-101 transfection significantly suppresses RLIP76 expression, which can transactivate phosphorylation of PI3K-Akt signaling, and resulted in an amplification of Bcl2-induced apoptosis. Furthermore, we demonstrated that RLIP76 overexpression could reverse the anti-tumor effects of miR-101 in DU145 and PC3 cells by using flow cytometry assay and MTT assay. Taken together, our results revealed that the effect of miR-101 on prostate cancer cell apoptosis was due to RLIP76 regulation of the PI3K/Akt/Bcl-2 signaling pathway. - Highlights: • miR-101 inhibited prostate cancer cell proliferation and enhanced apoptosis. • miR-101 directly targeted and regulated RLIP76 expression. • miR-101 suppressed PI3K/Akt/Bcl-2 signaling pathway by targeting RLIP76.

  5. Jujuboside A Protects H9C2 Cells from Isoproterenol-Induced Injury via Activating PI3K/Akt/mTOR Signaling Pathway

    PubMed Central

    Han, Dandan; Wan, Changrong; Liu, Fenghua; Xu, Xiaolong; Jiang, Linshu; Xu, Jianqin

    2016-01-01

    Jujuboside A is a kind of the saponins isolated from the seeds of Ziziphus jujuba, which possesses multiple biological effects, such as antianxiety, antioxidant, and anti-inflammatory effects; however, its mediatory effect on isoproterenol-stimulated cardiomyocytes has not been investigated yet. In this study, we tried to detect the protective effect and potential mechanism of JUA on ISO-induced cardiomyocytes injury. H9C2 cells were treated with ISO to induce cell damage. Cells were pretreated with JUA to investigate the effects on the cell viability, morphological changes, light chain 3 conversion, and the activation of PI3K/Akt/mTOR signaling pathway. Results showed that ISO significantly inhibited the cell viability in a time- and dose-dependent manner. JUA pretreatment could reverse the reduction of cell viability and better the injury of H9C2 cells induced by ISO. Western blot analysis showed that JUA could accelerate the phosphorylation of PI3K, Akt, and mTOR. Results also indicated that JUA could significantly decrease the ratio of microtubule-associated protein LC3-II/I in H9C2 cells. Taken together, our research showed that JUA could notably reduce the damage cause by ISO via promoting the phosphorylation of PI3K, Akt, and mTOR and inhibiting LC3 conversion, which may be a potential choice for the treatment of heart diseases. PMID:27293469

  6. Astragaloside IV inhibits doxorubicin-induced cardiomyocyte apoptosis mediated by mitochondrial apoptotic pathway via activating the PI3K/Akt pathway.

    PubMed

    Jia, Yuanyuan; Zuo, Daiying; Li, Zengqiang; Liu, Hanmo; Dai, Zhengning; Cai, Jiayi; Pang, Lili; Wu, Yingliang

    2014-01-01

    Doxorubicin (DOX) is a widely used antitumor drug whose application is seriously limited by its cardiotoxicity. Mitochondria-mediated cardiomyocyte apoptosis plays a critical role in DOX-induced cardiotoxicity (DIC). The aim of the present study was to investigate the protective effect of astragaloside IV (3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol, AS-IV), a pure saponin isolated from Astragalus membranaceus, against DOX-induced cardiomyocyte apoptosis in primary cultured neonatal rat cardiomyocytes. Immunocytochemistry and Microculture Tetrazolium (MTT) assays showed that AS-IV significantly reduced DOX-induced cardiomyocyte loss. Additionally, AS-IV markedly ameliorated DOX-caused cardiomyocyte dysfunction via restoring the beating cell ratio and beating rate in cardiomyocytes. Furthermore, AS-IV substantially reduced the mitochondrial reactive oxygen species (ROS) production and lactate dehydrogenase (LDH), creatine kinase-MB isoenzyme (CK-MB) and cytochrome c (CytC) release, and restored the reduced ATP level, succinate dehydrogenase (SDH) and ATP synthase activities induced by DOX, suggesting that AS-IV significantly attenuated DOX-induced mitochondrial damage and dysfunction. It was further observed that DOX-induced cardiomyocyte apoptosis, as qualitatively evaluated by Hoechst 33258 staining and accurately quantified by flow cytometry, was markedly inhibited by AS-IV. Western blot analysis manifested that AS-IV significantly inhibited the activation of mitochondrial apoptotic pathway (MAP) via inducing the phosphorylation of Akt and Bad. Furthermore, phosphatidylinositol 3-kinase (PI3K) inhibitor 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride (LY294002) remarkably inhibited the anti-apoptotic effect of AS-IV. Moreover, AS-IV didn't compromise the antitumor activity of DOX. Taken together, our findings indicate that AS-IV ameliorates DIC, and this beneficial effect appears to be dependent on the activation of the PI3K/Akt

  7. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

    SciTech Connect

    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

    2012-11-15

    Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p < 0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer. Highlights:

  8. The roles of PI3K/Akt signaling pathway in regulating MC3T3-E1 preosteoblast proliferation and differentiation on SLA and SLActive titanium surfaces.

    PubMed

    Gu, Ying-Xin; Du, Juan; Si, Mi-Si; Mo, Jia-Ji; Qiao, Shi-Chong; Lai, Hong-Chang

    2013-03-01

    Chemical modification to produce a hydrophilic microrough titanium (Ti) implant surface has been shown to increase osseointegration compared with microrough topography alone. This study aimed to investigate the roles of PI3K/Akt signaling pathway in regulating proliferation and differentiation of osteoblasts in response to surface microroughness and hydrophilicity. Ti disks were manufactured to present different surface morphologies: a smooth pretreatment surface (PT), a rough hydrophobic surface that was sand-blasted, large-grit, acid-etched (SLA), and an SLA surface with the same roughness that was chemically modified to possess high wettability/hydrophilicity (SLActive/modSLA). MC3T3-E1 cells were cultured on these substrates with or without LY294002, a PI3K inhibitor, and their behaviors, including cell viability (MTT colorimetric assay), alkaline phosphatase (ALP) activity, and osteogenic genes expression of osteopontin (OPN) and osteocalcin (OCN) were measured. Western blot was applied to detect the expression of PI3K/Akt signal pathway proteins. The results showed that a decrease in osteoblast proliferation associated with the Ti surfaces (SLActive > SLA > PT) correlated with an increase in activity of the osteogenic differentiation markers ALP. The peak of ALP activity appeared earlier at 7 days for the SLActive surfaces compared with the SLA and PT surfaces. Osteoblast proliferation, as well as the level of p-Akt, was significantly inhibited by LY294002 in all three Ti surfaces. The top value of ALP activity was increased with the inhibition of PI3K/Akt signaling pathway while the time of the peak appeared was not advanced. The expression levels of OPN and OCN were upregulated by the effect of surface roughness and hydrophilicity, which were further enhanced by LY294002. In conclusion, osteogenic responses to SLActive surface were moderately better than the SLA surface and protein expression studies indicated that PI3K/Akt signaling activation may be

  9. Hesperetin Inhibits Vascular Formation by Suppressing of the PI3K/AKT, ERK, and p38 MAPK Signaling Pathways.

    PubMed

    Kim, Gi Dae

    2014-12-01

    Hesperetin has been shown to possess a potential anti-angiogenic effect, including vascular formation by endothelial cells. However, the mechanisms underlying the potential anti-angiogenic activity of hesperetin are not fully understood. In the present study, we evaluated whether hesperetin has anti-angiogenic effects in human umbilical vascular endothelial cells (HUVECs). HUVECs were treated with 50 ng/mL vascular endothelial growth factor (VEGF) to induce proliferation as well as vascular formation, followed by treatment with several doses of hesperetin (25, 50, and 100 μM) for 24 h. Cell proliferation and vascular formation were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and tube formation assay, respectively. In addition, cell signaling related to cell proliferation and vascular formation was analyzed by western blot. Furthermore, a mouse aorta ring assay was performed to confirm the effect of hesperetin on vascular formation. Hesperetin treatment did not cause differences in HUVECs proliferation. However, hesperetin significantly inhibited VEGF-induced cell migration and tube formation of HUVECs (P<0.05). Moreover, hesperetin suppressed the expression of ERK, p38 MAPK, and PI3K/AKT in the VEGF-induced HUVECs. In an ex vivo model, hesperetin also suppressed microvessel sprouting of mouse aortic rings. Taken together, the findings suggest that hesperetin inhibited vascular formation by endothelial cells via the inhibition of the PI3K/AKT, ERK and p38 MAPK signaling.

  10. Induction of apoptosis and autophagy via sirtuin1- and PI3K/Akt/mTOR-mediated pathways by plumbagin in human prostate cancer cells

    PubMed Central

    Zhou, Zhi-Wei; Li, Xing-Xiao; He, Zhi-Xu; Pan, Shu-Ting; Yang, Yinxue; Zhang, Xueji; Chow, Kevin; Yang, Tianxin; Qiu, Jia-Xuan; Zhou, Qingyu; Tan, Jun; Wang, Dong; Zhou, Shu-Feng

    2015-01-01

    Plumbagin (PLB) has been shown to have anticancer activities in animal models, but the role of PLB in prostate cancer treatment is unclear. This study aimed to investigate the effects of PLB on apoptosis and autophagy and the underlying mechanisms in human prostate cancer cell lines PC-3 and DU145. Our study has shown that PLB had potent pro-apoptotic and pro-autophagic effects on PC-3 and DU145 cells. PLB induced mitochondria-mediated apoptosis and autophagy in concentration- and time-dependent manners in both PC-3 and DU145 cells. PLB induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase (MAPK) pathways and activation of 5′-AMP-dependent kinase (AMPK) as indicated by their altered phosphorylation, contributing to the pro-autophagic activity of PLB. Modulation of autophagy altered basal and PLB-induced apoptosis in both cell lines. Furthermore, PLB downregulated sirtuin 1 (Sirt1), and inhibition of Sirt1 enhanced autophagy, whereas the induction of Sirt1 abolished PLB-induced autophagy in PC-3 and DU145 cells. In addition, PLB downregulated pre-B cell colony-enhancing factor/visfatin, and the inhibition of pre-B cell colony-enhancing factor/visfatin significantly enhanced basal and PLB-induced apoptosis and autophagy in both cell lines. Moreover, reduction of intracellular reactive oxygen species (ROS) level attenuated the apoptosis- and autophagy-inducing effects of PLB on both PC-3 and DU145 cells. These findings indicate that PLB promotes apoptosis and autophagy in prostate cancer cells via Sirt1- and PI3K/Akt/mTOR-mediated pathways with contribution from AMPK-, p38 MAPK-, visfatin-, and ROS-associated pathways. PMID:25834399

  11. Modulation of the PI3K/Akt Pathway and Bcl-2 Family Proteins Involved in Chicken’s Tubular Apoptosis Induced by Nickel Chloride (NiCl2)

    PubMed Central

    Guo, Hongrui; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Wu, Bangyuan; Chen, Kejie; Deng, Jie

    2015-01-01

    Exposure of people and animals to environments highly polluted with nickel (Ni) can cause pathologic effects. Ni compounds can induce apoptosis, but the mechanism and the pathway of Ni compounds-induced apoptosis are unclear. We evaluated the alterations of apoptosis, mitochondrial membrane potential (MMP), phosphoinositide-3-kinase (PI3K)/serine-threonine kinase (Akt) pathway, and Bcl-2 family proteins induced by nickel chloride (NiCl2) in the kidneys of broiler chickens, using flow cytometry, terminal deoxynucleotidyl transferase 2ʹ-deoxyuridine 5ʹ-triphosphate dUTP nick end-labeling (TUNEL), immunohistochemstry and quantitative real-time polymerase chain reaction (qRT-PCR). We found that dietary NiCl2 in excess of 300 mg/kg resulted in a significant increase in apoptosis, which was associated with decrease in MMP, and increase in apoptosis inducing factor (AIF) and endonuclease G (EndoG) protein and mRNA expression. Concurrently, NiCl2 inhibited the PI3K/Akt pathway, which was characterized by decreasing PI3K, Akt1 and Akt2 mRNA expression levels. NiCl2 also reduced the protein and mRNA expression of anti-apoptotic Bcl-2 and Bcl-xL and increased the protein and mRNA expression of pro-apoptotic Bax and Bak. These results show that NiCl2 causes mitochondrial-mediated apoptosis by disruption of MMP and increased expression of AIF and EndoG mRNA and protein, and that the underlying mechanism of MMP loss involves the Bcl-2 family proteins modulation and PI3K/Akt pathway inhibition. PMID:26404262

  12. Halofuginone inhibits Smad3 phosphorylation via the PI3K/Akt and MAPK/ERK pathways in muscle cells: Effect on myotube fusion

    SciTech Connect

    Roffe, Suzy; Hagai, Yosey; Pines, Mark; Halevy, Orna

    2010-04-01

    Halofuginone, a novel inhibitor of Smad3 phosphorylation, has been shown to inhibit muscle fibrosis and to improve cardiac and skeletal muscle functions in the mdx mouse model of Duchenne muscular dystrophy. Here, we demonstrate that halofuginone promotes the phosphorylation of Akt and mitogen-activated protein kinase (MAPK) family members in a C2 muscle cell line and in primary myoblasts derived from wild-type and mdx mice diaphragms. Halofuginone enhanced the association of phosphorylated Akt and MAPK/extracellular signal-regulated protein kinase (ERK) with the non-phosphorylated form of Smad3, accompanied by a reduction in Smad3 phosphorylation levels. This reduction was reversed by inhibitors of the phosphoinositide 3'-kinase/Akt (PI3K/Akt) and MAPK/ERK pathways, suggesting their specific role in mediating halofuginone's inhibitory effect on Smad3 phosphorylation. Halofuginone enhanced Akt, MAPK/ERK and p38 MAPK phosphorylation and inhibited Smad3 phosphorylation in myotubes, all of which are crucial for myotube fusion. In addition, halofuginone increased the association Akt and MAPK/ERK with Smad3. As a consequence, halofuginone promoted myotube fusion, as reflected by an increased percentage of C2 and mdx myotubes containing high numbers of nuclei, and this was reversed by specific inhibitors of the PI3K and MAPK/ERK pathways. Together, the data suggest a role, either direct or via inhibition of Smad3 phosphorylation, for Akt or MAPK/ERK in halofuginone-enhanced myotube fusion, a feature which is crucial to improving muscle function in muscular dystrophies.

  13. The Role of PI3K/Akt/mTOR Signaling in Gastric Carcinoma

    PubMed Central

    Matsuoka, Tasuku; Yashiro, Masakazu

    2014-01-01

    The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is one of the key signaling pathways induced by various receptor-tyrosine kinases. Accumulating evidence shows that this pathway is an important promoter of cell growth, metabolism, survival, metastasis, and resistance to chemotherapy. Genetic alterations in the PI3K/Akt/mTOR pathway in gastric carcinoma have often been demonstrated. Many kinds of molecular targeting therapies are currently undergoing clinical testing in patients with solid tumors. However, with the exception of the ErbB2-targeting antibody, targeting agents, including PI3K/Akt/mTOR inhibitors, have not been approved for treatment of patients with gastric carcinoma. This review summarizes the current knowledge on PI3K/Akt/mTOR signaling in the pathogenesis of gastric carcinoma and the possible therapeutic targets for gastric carcinoma. Improved knowledge of the PI3K/Akt/mTOR pathway in gastric carcinoma will be useful in understanding the mechanisms of tumor development and for identifying ideal targets of anticancer therapy for gastric carcinoma. PMID:25003395

  14. Identification of novel therapeutic targets in the PI3K/AKT/mTOR pathway in hepatocellular carcinoma using targeted next generation sequencing.

    PubMed

    Janku, Filip; Kaseb, Ahmed O; Tsimberidou, Apostolia M; Wolff, Robert A; Kurzrock, Razelle

    2014-05-30

    Understanding genetic aberrations in cancer leads to discovery of new targets for cancer therapies. The genomic landscape of hepatocellular carcinoma (HCC) has not been fully described. Therefore, patients with refractory advanced/metastatic HCC referred for experimental therapies, who had adequate tumor tissue available, had targeted next generation sequencing (NGS) of their tumor samples using the Illumina HiSeq 2000 platform (Foundation One, Foundation Medicine, MA) and their treatment outcomes were analyzed. In total, NGS was obtained for 14 patients (median number of prior therapies, 1) with advanced/metastatic HCC. Of these 14 patients, 10 (71%) were men, 4 (29%) women, 6 (43%) had hepatitis B or C-related HCC. NGS revealed at least 1 molecular abnormality in 12 patients (range 0-8, median 2). Detected molecular aberrations led to putative activation of the PI3K/AKT/mTOR pathway (n=3 [mTOR, PIK3CA, NF1]), Wnt pathway (n=6 [CTNNA1, CTNNB1]), MAPK pathway (n=2 [MAP2K1, NRAS]), and aberrant DNA repair mechanisms, cell cycle control and apoptosis (n=18 [ATM, ATR, BAP1, CCND1, CDKN2A, CDK4, FGF3, FGF4, FGF19, MCL1, MDM2, RB1, TP53]). Of the 3 patients with molecular aberrations putatively activating the PI3K/AKT/mTOR pathway, 2 received therapies including a mTOR inhibitor and all demonstrated therapeutic benefit ranging from a partial response to minor shrinkage per RECIST (-30%, -15%; respectively). In conclusion, genomic alterations are common in advanced HCC. Refractory patients with alterations putatively activating the PI3K/AKT/mTOR pathway demonstrated early signals of clinical activity when treated with therapies targeting mTOR.

  15. Exendin-4 protects adipose-derived mesenchymal stem cells from apoptosis induced by hydrogen peroxide through the PI3K/Akt-Sfrp2 pathways.

    PubMed

    Zhou, Hao; Yang, Junjie; Xin, Ting; Li, Dandan; Guo, Jun; Hu, Shunyin; Zhou, Shanshan; Zhang, Tao; Zhang, Ying; Han, Tianwen; Chen, Yundai

    2014-12-01

    Adipose-derived mesenchymal stem cells (ADMSCs)-based therapy is a promising modality for the treatment of myocardial infarction in the future. However, the majority of transplanted cells are readily lost after transplantation because of hypoxia and oxidative stress. An efficient means to enhance the ability of ADMSCs to survive under pathologic conditions is required. In our study, we explored the effects of exendin-4 (Ex-4) on ADMSCs apoptosis in vitro induced by hydrogen peroxide, focusing in particular on mitochondrial apoptotic pathways and PI3K/Akt-secreted frizzled-related protein 2 (Sfrp2) survival signaling. We demonstrated that ADMSCs subjected to H2O2 for 12h exhibited impaired mitochondrial function and higher apoptotic rate. However, Ex-4 (1-20 nM) preconditioning for 12h could protect ADMSCs against H2O2-mediated apoptosis in a dose-dependent manner. Furthermore, Ex-4 pretreatment upregulated the levels of superoxide dismutase and glutathione as well as downregulating the production of reactive oxygen species and malondialdehyde. Western blots revealed that increased antiapoptotic proteins Bcl-2 and c-IAP1/2 as well as decreased proapoptotic proteins Bax and cytochrome c appeared in ADMSCs with Ex-4 incubation, which inhibited the caspase-9-involved mitochondrial apoptosis pathways with evidence showing inactivation of caspase-9/3 and preservation of mitochondrial membrane potential. Furthermore, we illustrated that Ex-4 enhanced Akt phosphorylation, which increased the expression of Sfrp2. Notably, blockade of the PI3K/Akt pathway or knockdown of Sfrp2 with siRNA obviously abolished the protective effects of Ex-4 on mitochondrial function and ADMSCs apoptosis under H2O2. In summary, this study confirmed that H2O2 induced ADMSCs apoptosis through mitochondria-dependent cell death pathways, and Ex-4 preconditioning may reduce such apoptosis of ADMSCs through the PI3K/Akt-Sfrp2 pathways.

  16. Loss of Mel-18 induces tumor angiogenesis through enhancing the activity and expression of HIF-1α mediated by the PTEN/PI3K/Akt pathway.

    PubMed

    Park, J H; Lee, J Y; Shin, D H; Jang, K S; Kim, H J; Kong, Gu

    2011-11-10

    Mel-18 has been implicated in several processes in tumor progression, in which the Akt pathway is involved as an important key molecular event. However, the function of Mel-18 in human cancers has not been fully established yet. Here, we examined the effect of Mel-18 on tumor angiogenesis in human breast cancer, and found that Mel-18 was a novel regulator of HIF-1α. Mel-18 negatively regulated the HIF-1α expression and its target gene VEGF transcription during both normoxia and hypoxia. We demonstrated that Mel-18 regulated the HIF-1α expression and activity via the PI3K/Akt pathway. Loss of Mel-18 downregulated Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression, consequently activating the PI3K/Akt/MDM2 pathway, and leading to an increase of HIF-1α protein level. Mel-18 modulated the HIF-1α transcriptional activity via regulating the cytoplasmic retention of FOXO3a, a downstream effector of Akt, and recruitment of HIF-1α/CBP complex to the VEGF promoter. Furthermore, our data shows that Mel-18 blocked tumor angiogenesis both in vitro and in vivo. Mel-18 overexpression inhibited in vitro tube formation in human umbilical endothelial cells (HUVECs). Xenografts in NOD/SCID mice derived from stably Mel-18 knocked down MCF7 human breast cancer cells showed increased tumor volume, microvessel density, and phospho-Akt and HIF-1α expression levels. In conclusion, our findings provide that Mel-18 is a novel regulator of tumor angiogenesis through regulating HIF-1α and its target VEGF expressions mediated by the PTEN/PI3K/Akt pathway, suggesting a new tumor-suppressive role of Mel-18 in human breast cancer.

  17. Selective Inhibition of PI3K/Akt/mTOR Signaling Pathway Regulates Autophagy of Macrophage and Vulnerability of Atherosclerotic Plaque

    PubMed Central

    Zhai, Chungang; Cheng, Jing; Mujahid, Haroon; Wang, Hefeng; Kong, Jing; Yin, Yue; Li, Jifu; Zhang, Yun; Ji, Xiaoping; Chen, Wenqiang

    2014-01-01

    Macrophage infiltration contributes to the instability of atherosclerotic plaques. In the present study, we investigated whether selective inhibition of PI3K/Akt/mTOR signaling pathway can enhance the stability of atherosclerotic plaques by activation of macrophage autophagy. In vitro study, selective inhibitors or siRNA of PI3K/Akt/mTOR pathways were used to treat the rabbit's peritoneal primary macrophage cells. Inflammation related cytokines secreted by macrophages were measured. Ultrastructure changes of macrophages were examined by transmission electron microscope. mRNA or protein expression levels of autophagy related gene Beclin 1, protein 1 light chain 3 II dots (LC3-II) or Atg5-Atg12 conjugation were assayed by quantitative RT-PCR or Western blot. In vivo study, vulnerable plaque models were established in 40 New Zealand White rabbits and then drugs or siRNA were given for 8 weeks to inhibit the PI3K/Akt/mTOR signaling pathway. Intravascular ultrasound (IVUS) was performed to observe the plaque imaging. The ultrastructure of the abdominal aortic atherosclerosis lesions were analyzed with histopathology. RT-PCR or Western blot methods were used to measure the expression levels of corresponding autophagy related molecules. We found that macrophage autophagy was induced in the presence of Akt inhibitor, mTOR inhibitor and mTOR-siRNA in vitro study, while PI3K inhibitor had the opposite role. In vivo study, we found that macrophage autophagy increased significantly and the rabbits had lower plaque rupture incidence, lower plaque burden and decreased vulnerability index in the inhibitors or siRNA treated groups. We made a conclusion that selective inhibition of the Akt/mTOR signal pathway can reduce macrophages and stabilize the vulnerable atherosclerotic plaques by promoting macrophage autophagy. PMID:24599185

  18. Silencing of VEGF inhibits human osteosarcoma angiogenesis and promotes cell apoptosis via VEGF/PI3K/AKT signaling pathway

    PubMed Central

    Peng, Ningning; Gao, Shuming; Guo, Xu; Wang, Guangya; Cheng, Cai; Li, Min; Liu, Kehun

    2016-01-01

    Background: Osteosarcoma is a kind of highly malignant tumor and the growth and metastasis is closely related to angiogenesis. Vascular endothelial growth factor (VEGF) is an important angiogenesis-promoting factor. In the current study, we investigated the effects of suppressed VEGF on osteosarcoma and its molecular mechanism provided for a basis by targeting angiogenesis. Material/Methods: We established bearing human osteosarcoma Wistar rats model by subcutaneous inoculation of human SaOS-2 cells and the adenovirus vector Ad-VEGF-siRNA was constructed for further study. We assessed the efficiency of VEGF silencing and its influence on SaOS-2 cells. The expression of mRNA and protein were detected by RT-PCR and western blotting, respectively. Intratumoral microvessel density (MVD), VEGF and CD31 were evaluated by immunohistochemistry. We detected the cell apoptotic rates by flow cytometry. Results: Our results indicated that Ad-VEGF-siRNA could effectively suppressed the expression of VEGF expression, inhibited the proliferation capability and promoted apoptosis of SaOS-2 cells in vitro. Silencing of VEGF expression also suppress osteosarcoma tumor growth and reduce osteosarcoma angiogenesis in the Wistar rats model in vivo. Furthermore, We found that phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) activation were considerably reduced while inhibition VEGF expression in SaOS-2 cells. Conclusion: Our data demonstrated that VEGF silencing could suppress cells proliferation, promote cells apoptosis and reduce osteosarcoma angiogenesis through inactivation of VEGF/PI3K/AKT signaling pathway. PMID:27158386

  19. Catalase expression in MCF-7 breast cancer cells is mainly controlled by PI3K/Akt/mTor signaling pathway.

    PubMed

    Glorieux, Christophe; Auquier, Julien; Dejeans, Nicolas; Sid, Brice; Demoulin, Jean-Baptiste; Bertrand, Luc; Verrax, Julien; Calderon, Pedro Buc

    2014-05-15

    Catalase is an antioxidant enzyme that catalyzes mainly the transformation of hydrogen peroxide into water and oxygen. Although catalase is frequently down-regulated in tumors the underlying mechanism remains unclear. Few transcription factors have been reported to directly bind the human catalase promoter. Among them FoxO3a has been proposed as a positive regulator of catalase expression. Therefore, we decided to study the role of the transcription factor FoxO3a and the phosphatidylinositol-3 kinase (PI3K) signaling pathway, which regulates FoxO3a, in the expression of catalase. To this end, we developed an experimental model of mammary breast MCF-7 cancer cells that acquire resistance to oxidative stress, the so-called Resox cells, in which catalase is overexpressed as compared with MCF-7 parental cell line. In Resox cells, Akt expression is decreased but its phosphorylation is enhanced when compared with MCF-7 cells. A similar profile is observed for FoxO3a, with less total protein but more phosphorylated FoxO3a in Resox cells, correlating with its higher Akt activity. The modulation of FoxO3a expression by knockdown and overexpression strategies did not affect catalase expression, neither in MCF-7 nor in Resox cells. Inhibition of PI3K and mTOR by LY295002 and rapamycin, respectively, decreases the phosphorylation of downstream targets (i.e. GSK3β and p70S6K) and leads to an increase of catalase expression only in MCF-7 but not in Resox cells. In conclusion, FoxO3a does not appear to play a critical role in the regulation of catalase expression in both cancer cells. Only MCF-7 cells are sensitive and dependent on PI3K/Akt/mTOR signaling.

  20. Folic Acid Represses Hypoxia-Induced Inflammation in THP-1 Cells through Inhibition of the PI3K/Akt/HIF-1α Pathway.

    PubMed

    Huang, Xiaoyan; He, Zhiying; Jiang, Xinwei; Hou, Mengjun; Tang, Zhihong; Zhen, Xiaozhou; Liang, Yuming; Ma, Jing

    2016-01-01

    Though hypoxia has been implicated as a cause of inflammation, the underlying mechanism is not well understood. Folic acid has been shown to provide protection against oxidative stress and inflammation in patients with cardiovascular disease and various models approximating insult to tissue via inflammation. It has been reported that hypoxia-induced inflammation is associated with oxidative stress, upregulation of hypoxia-inducible factor 1-alpha (HIF-1α), and production of pro-inflammatory molecules. Whether folic acid protects human monocytic cells (THP-1 cells) against hypoxia-induced damage, however, remains unknown. We used THP-1 cells to establish a hypoxia-induced cellular injury model. Pretreating THP-1 cells with folic acid attenuated hypoxia-induced inflammatory responses, including a decrease in protein and mRNA levels of interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α), coupled with increased levels of IL-10. Folic acid also reduced hypoxia-induced Akt phosphorylation and decreased nuclear accumulation of HIF-1α protein. Both LY294002 (a selective inhibitor of phosphatidyl inositol-3 kinase, PI3K) and KC7F2 (a HIF-1α inhibitor) reduced levels of hypoxia-induced inflammatory cytokines. We also found that insulin (an Akt activator) and dimethyloxallyl glycine (DMOG, a HIF-1α activator) induced over-expression of inflammatory cytokines, which could be blocked by folic acid. Taken together, these findings demonstrate how folic acid attenuates the hypoxia-induced inflammatory responses of THP-1 cells through inhibition of the PI3K/Akt/HIF-1α pathway.

  1. Supercritical Fluid Extract of Spent Coffee Grounds Attenuates Melanogenesis through Downregulation of the PKA, PI3K/Akt, and MAPK Signaling Pathways

    PubMed Central

    Huang, Huey-Chun; Wei, Chien-Mei; Siao, Jen-Hung; Tsai, Tsang-Chi; Ko, Wang-Ping; Chang, Kuei-Jen; Hii, Choon-Hoon; Chang, Tsong-Min

    2016-01-01

    The mode of action of spent coffee grounds supercritical fluid CO2 extract (SFE) in melanogenesis has never been reported. In the study, the spent coffee grounds were extracted by the supercritical fluid CO2 extraction method; the chemical constituents of the SFE were investigated by gas chromatography-mass spectrometry (GC-MS). The effects of the SFE and its major fatty acid components on melanogenesis were evaluated by mushroom tyrosinase activity assay and determination of intracellular tyrosinase activity and melanin content. The expression level of melanogenesis-related proteins was analyzed by western blotting assay. The results revealed that the SFE of spent coffee grounds (1–10 mg/mL) and its major fatty acids such as linoleic acid and oleic acid (6.25–50 μM) effectively suppressed melanogenesis in the B16F10 murine melanoma cells. Furthermore, the SFE decreased the expression of melanocortin 1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). The SFE also decreased the protein expression levels of p-JNK, p-p38, p-ERK, and p-CREB. Our results revealed that the SFE of spent coffee grounds attenuated melanogenesis in B16F10 cells by downregulation of protein kinase A (PKA), phosphatidylinositol-3-kinase (PI3K/Akt), and mitogen-activated protein kinases (MAPK) signaling pathways, which may be due to linoleic acid and oleic acid. PMID:27375763

  2. Supercritical Fluid Extract of Spent Coffee Grounds Attenuates Melanogenesis through Downregulation of the PKA, PI3K/Akt, and MAPK Signaling Pathways.

    PubMed

    Huang, Huey-Chun; Wei, Chien-Mei; Siao, Jen-Hung; Tsai, Tsang-Chi; Ko, Wang-Ping; Chang, Kuei-Jen; Hii, Choon-Hoon; Chang, Tsong-Min

    2016-01-01

    The mode of action of spent coffee grounds supercritical fluid CO2 extract (SFE) in melanogenesis has never been reported. In the study, the spent coffee grounds were extracted by the supercritical fluid CO2 extraction method; the chemical constituents of the SFE were investigated by gas chromatography-mass spectrometry (GC-MS). The effects of the SFE and its major fatty acid components on melanogenesis were evaluated by mushroom tyrosinase activity assay and determination of intracellular tyrosinase activity and melanin content. The expression level of melanogenesis-related proteins was analyzed by western blotting assay. The results revealed that the SFE of spent coffee grounds (1-10 mg/mL) and its major fatty acids such as linoleic acid and oleic acid (6.25-50 μM) effectively suppressed melanogenesis in the B16F10 murine melanoma cells. Furthermore, the SFE decreased the expression of melanocortin 1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). The SFE also decreased the protein expression levels of p-JNK, p-p38, p-ERK, and p-CREB. Our results revealed that the SFE of spent coffee grounds attenuated melanogenesis in B16F10 cells by downregulation of protein kinase A (PKA), phosphatidylinositol-3-kinase (PI3K/Akt), and mitogen-activated protein kinases (MAPK) signaling pathways, which may be due to linoleic acid and oleic acid. PMID:27375763

  3. Glucagon-like peptide-1 protects cardiomyocytes from advanced oxidation protein product-induced apoptosis via the PI3K/Akt/Bad signaling pathway.

    PubMed

    Zhang, Hua; Xiong, Zhouyi; Wang, Jiao; Zhang, Shuangshuang; Lei, Lei; Yang, Li; Zhang, Zhen

    2016-02-01

    Cardiomyocyte apoptosis is a major event in the pathogenesis of diabetic cardiomyopathy. Currently, no single effective treatment for diabetic cardiomyopathy exists. The present study investigated whether advanced oxidative protein products (AOPPs) have a detrimental role in the survival of cardiomyocytes and if glucagon-like peptide-1 (GLP-1) exerts a cardioprotective effect under these circumstances. The present study also aimed to determine the underlying mechanisms. H9c2 cells were exposed to increasing concentrations of AOPPs in the presence or absence of GLP-1, and the viability and apoptotic rate were detected using a cell counting kit-8 assay and flow cytometry, respectively. In addition, a phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) inhibitor, LY294002, was employed to illustrate the mechanism of the antiapoptotic effect of GLP-1. The expression levels of the apoptotic-associated proteins, Akt, B-cell lymphoma (Bcl)-2, Bcl-2-associated death promoter (Bad), Bcl-2-associated X protein (Bax) and caspase-3 were measured by western blotting. It was revealed that GLP-1 significantly attenuated AOPP-induced cell toxicity and apoptosis. AOPPs inactivated the phosphorylation of Akt, reduced the phosphorylation of Bad, decreased the expression of Bcl-2, increased the expression of Bax and the activation of caspase-3 in H9c2 cells. GLP-1 reversed the above changes induced by AOPPs and the protective effects of GLP-1 were abolished by the PI3K inhibitor, LY294002. In conclusion, the present data suggested that GLP-1 protected cardiomyocytes against AOPP-induced apoptosis, predominantly via the PI3K/Akt/Bad pathway. These results provided a conceivable mechanism for the development of diabetic cardiomyopathy and rendered a novel application of GLP-1 exerting favorable cardiac effects for the treatment of diabetic cardiomyopathy.

  4. Glucagon-like peptide-1 protects cardiomyocytes from advanced oxidation protein product-induced apoptosis via the PI3K/Akt/Bad signaling pathway

    PubMed Central

    ZHANG, HUA; XIONG, ZHOUYI; WANG, JIAO; ZHANG, SHUANGSHUANG; LEI, LEI; YANG, LI; ZHANG, ZHEN

    2016-01-01

    Cardiomyocyte apoptosis is a major event in the pathogenesis of diabetic cardiomyopathy. Currently, no single effective treatment for diabetic cardiomyopathy exists. The present study investigated whether advanced oxidative protein products (AOPPs) have a detrimental role in the survival of cardiomyocytes and if glucagon-like peptide-1 (GLP-1) exerts a cardioprotective effect under these circumstances. The present study also aimed to determine the underlying mechanisms. H9c2 cells were exposed to increasing concentrations of AOPPs in the presence or absence of GLP-1, and the viability and apoptotic rate were detected using a cell counting kit-8 assay and flow cytometry, respectively. In addition, a phosphatidylino-sitol-4,5-bisphosphate 3-kinase (PI3K) inhibitor, LY294002, was employed to illustrate the mechanism of the antiapoptotic effect of GLP-1. The expression levels of the apoptotic-associated proteins, Akt, B-cell lymphoma (Bcl)-2, Bcl-2-associated death promoter (Bad), Bcl-2-associated X protein (Bax) and caspase-3 were measured by western blotting. It was revealed that GLP-1 significantly attenuated AOPP-induced cell toxicity and apoptosis. AOPPs inactivated the phosphorylation of Akt, reduced the phosphorylation of Bad, decreased the expression of Bcl-2, increased the expression of Bax and the activation of caspase-3 in H9c2 cells. GLP-1 reversed the above changes induced by AOPPs and the protective effects of GLP-1 were abolished by the PI3K inhibitor, LY294002. In conclusion, the present data suggested that GLP-1 protected cardiomyocytes against AOPP-induced apoptosis, predominantly via the PI3K/Akt/Bad pathway. These results provided a conceivable mechanism for the development of diabetic cardiomyopathy and rendered a novel application of GLP-1 exerting favorable cardiac effects for the treatment of diabetic cardiomyopathy. PMID:26717963

  5. Effects of D-Pinitol on Insulin Resistance through the PI3K/Akt Signaling Pathway in Type 2 Diabetes Mellitus Rats.

    PubMed

    Gao, Yunfeng; Zhang, Mengna; Wu, Tianchen; Xu, Mengying; Cai, Haonan; Zhang, Zesheng

    2015-07-01

    D-pinitol, a compound isolated from Pinaceae and Leguminosae plants, has been reported to possess insulin-like properties. Although the hypoglycemic activity of D-pinitol was recognized in recent years, the molecular mechanism of D-pinitol in the treatment of diabetes mellitus remains unclear. In this investigation, a model of type 2 diabetes mellitus (T2DM) with insulin resistance was established by feeding a high-fat diet (HFD) and injecting streptozocin (STZ) to Sprague-Dawley (SD) rats, targeting the exploration of more details of the mechanism in the therapy of T2DM. D-pinitol was administrated to the diabetic rats as two doses [30, 60 mg/(kg·body weight·day)]. The level of fasting blood glucose (FBG) was decreased 12.63% in the high-dosage group, and the ability of oral glucose tolerance was improved in D-pinitol-treated groups. The biochemical indices revealed that D-pinitol had a positive effect on hypoglycemic activity. Western boltting suggested that D-pinitol could promote the expression of the phosphatidylinositol-3-kinase (PI3K) p85, PI3Kp110, as well as the downstream target protein kinase B/Akt (at Ser473). Besides, D-pinitol inhibited the expression of glycogen synthesis kinase-3β (GSK-3β) protein and regulated the expression of glycogen synthesis (GS) protein and then accelerated the glycogen synthesis. Above all, D-pinitol played a positive role in regulating insulin-mediated glucose uptake in the liver through translocation and activation of the PI3K/Akt signaling pathway in T2DM rats.

  6. Dimethyloxaloylglycine Promotes the Angiogenic Activity of Mesenchymal Stem Cells Derived from iPSCs via Activation of the PI3K/Akt Pathway for Bone Regeneration

    PubMed Central

    Zhang, Jieyuan; Guan, Junjie; Qi, Xin; Ding, Hao; Yuan, Hong; Xie, Zongping; Chen, Chunyuan; Li, Xiaolin; Zhang, Changqing; Huang, Yigang

    2016-01-01

    The vascularization of tissue-engineered bone is a prerequisite step for the successful repair of bone defects. Hypoxia inducible factor-1α (HIF-1α) plays an essential role in angiogenesis-osteogenesis coupling during bone regeneration and can activate the expression of angiogenic factors in mesenchymal stem cells (MSCs). Dimethyloxaloylglycine (DMOG) is an angiogenic small molecule that can inhibit prolyl hydroxylase (PHD) enzymes and thus regulate the stability of HIF-1α in cells at normal oxygen tension. Human induced pluripotent stem cell-derived MSCs (hiPSC-MSCs) are promising alternatives for stem cell therapy. In this study, we evaluated the effect of DMOG on promoting hiPSC-MSCs angiogenesis in tissue-engineered bone and simultaneously explored the underlying mechanisms in vitro. The effectiveness of DMOG in improving the expression of HIF-1α and its downstream angiogenic genes in hiPSC-MSCs demonstrated that DMOG significantly enhanced the gene and protein expression profiles of angiogenic-related factors in hiPSC-MSCs by sustaining the expression of HIF-1α. Further analysis showed that DMOG-stimulated hiPSC-MSCs angiogenesis was associated with the phosphorylation of protein kinase B (Akt) and with an increase in VEGF production. The effects could be blocked by the addition of the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. In a critical-sized calvarial defect model in rats, DMOG-treated hiPSC-MSCs showed markedly improved angiogenic capacity in the tissue-engineered bone, leading to bone regeneration. Collectively, the results indicate that DMOG, via activation of the PI3K/Akt pathway, promotes the angiogenesis of hiPSC-MSCs in tissue-engineered bone for bone defect repair and that DMOG-treated hiPSC-MSCs can be exploited as a potential therapeutic tool in bone regeneration. PMID:27194942

  7. PI3K/AKT, JNK, and ERK pathways are not crucial for the induction of cholesterol biosynthesis gene transcription in intestinal epithelial cells following treatment with the potato glycoalkaloid alpha-chaconine.

    PubMed

    Mandimika, Tafadzwa; Baykus, Hakan; Poortman, Jenneke; Garza, Cutberto; Kuiper, Harry; Peijnenburg, Ad

    2008-09-24

    We previously reported that exposure of the intestinal epithelial Caco-2 cell line to noncytotoxic concentrations of potato glycoalkaloids resulted in increased expression of cholesterol biosynthesis genes. Genes involved in mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/v-akt murine thymoma viral oncogene homologue (AKT) pathways and their downstream effectors such as Jun, c-Myc, and Fos also were induced. MAPK and PI3K/AKT pathways have been described to regulate the activity of sterol regulatory element binding transcription factors (SREBPs) and consequently the expression of cholesterol biosynthesis genes. In this study, to understand the mechanism of induction of cholesterol biosynthesis upon alpha-chaconine treatment, its effect on SREBP-2 protein levels was investigated. We also examined whether MAPK and PI3K/AKT pathways are required for the observed induction of these genes following exposure of cells to alpha-chaconine. Differentiated Caco-2 cells were pretreated with LY294002 (PI3K inhibitor), PD98059 (MEK1 inhibitor), or SP600125 (JNK inhibitor) or a combination of all inhibitors for 24 h prior to coincubation with 10 microM alpha-chaconine for 6 h. Significant increases in precursor and mature protein levels of SREBP-2 were observed after alpha-chaconine exposure. We also observed that alpha-chaconine treatment resulted in significant phosphorylation of AKT, extracellular signal related protein kinase (ERK), and c-jun N terminal protein kinase (JNK) but not that of p38. In general, the kinase inhibitor experiments revealed that phosphorylation of kinases of PI3K/AKT, ERK, and JNK pathways was not crucial for the induction of expression of cholesterol biosynthesis genes, with the exception of SC5DL. The transcription of this later gene was reduced when all three pathways were inhibited. On the basis of these results, it can be postulated that other mechanisms, which may be independent of the MAPK and PI3K/AKT pathways

  8. Down-Regulation of MicroRNA-223 Promotes Degranulation via the PI3K/Akt Pathway by Targeting IGF-1R in Mast Cells

    PubMed Central

    Xu, Hong; Zhou, Hui; Yang, Qian-Yuan; Liu, Feng; Zhou, Guo-Ping

    2015-01-01

    Background Mast cells play a central role in allergic and inflammatory disorders by inducing degranulation and inflammatory mediator release. Recent reports have shown that miRNAs play an important role in inflammatory response regulation. Therefore, the role of miR-223 in mast cells was investigated. Methods The expression of miR-223 was quantified by quantitative real-time polymerase chain reaction (qRT-PCR) in immunoglobulin E (IgE)-mediated mast cells. After successful miR-223 inhibition by transfection, degranulation was detected in IgE-mediated mast cells. The phosphorylation of IκB-α and Akt were examined using western blotting. NF-κB was tested using electrophoretic mobility shift assay. PI3K-inhibitor (LY294002) was used to investigate whether the PI3K/Akt pathway was essential for mast cell activation. The TargetScan database and a luciferase reporter system were used to identify whether insulin-like growth factor 1 receptor (IGF-1R) is a direct target of miR-223. Results MiR-223 expression was up-regulated in IgE-mediated mast cells, whereas its down-regulation promoted mast cell degranulation. Levels of IκB-α and Akt phosphorylation as well as NF-κB were increased in miR-223 inhibitor cells. LY294002 could block the PI3K/Akt signaling pathway and rescue the promotion caused by suppressing miR-223 in mast cells. IGF-1R was identified as a direct target of miR-223. Conclusions These findings suggest that down-regulation of miR-223 promotes degranulation via the PI3K/Akt pathway by targeting IGF-1R in mast cells. PMID:25875646

  9. Anastrozole and everolimus in advanced gynecologic and breast malignancies: activity and molecular alterations in the PI3K/AKT/mTOR pathway

    PubMed Central

    Wheler, Jennifer J.; Moulder, Stacy L.; Naing, Aung; Janku, Filip; Piha-Paul, Sarina A.; Falchook, Gerald S.; Zinner, Ralph; Tsimberidou, Apostolia M.; Fu, Siqing; Hong, David S.; Atkins, Johnique T.; Yelensky, Roman; Stephens, Philip J.; Kurzrock, Razelle

    2014-01-01

    Background: Since PI3K/AKT/mTOR pathway activation diminishes the effects of hormone therapy, combining aromatase inhibitors (anatrozole) with mTOR inhibitors (everolimus) was investigated. Patients and Methods: We evaluated anastrozole and everolimus in 55 patients with metastatic estrogen (ER) and/or progesterone receptor (PR)-positive breast and gynecologic tumors. Endpoints were safety, antitumor activity and molecular correlates. Results: Full doses of anastrozole (1 mg PO daily) and everolimus (10 mg PO daily) were well tolerated. Twelve of 50 evaluable patients (24%) (median = 3 prior therapies) achieved stable disease (SD) ≥ 6 months/partial response (PR)/complete response (CR) (n = 5 (10%) with PR/CR): 9 of 32 (28%) with breast cancer (n=5 (16%) with PR/CR); 2 of 10 (20%), ovarian cancer; and 1 of 6 (17%), endometrial cancer. Six of 22 patients (27%) with molecular alterations in the PI3K/AKT/mTOR pathway achieved SD ≥ 6 months/PR/CR. Six of 8 patients (75%) with SD ≥ 6 months/PR/CR with molecular testing demonstrated at least one alteration in the PI3K/AKT/mTOR pathway: mutations in PIK3CA (n=3) and AKT1 (n=1) or PTEN loss (n=3). All three responders (CR (n = 1); PR (n=2)) who had next generation sequencing demonstrated additional alterations: amplifications in CCNE1, IRS2, MCL1, CCND1, FGFR1 and MYC and a rearrangement in PRKDC. Conclusions: Combination anastrozole and everolimus is well tolerated at full approved doses, and is active in heavily-pretreated patients with ER and/or PR-positive breast, ovarian and endometrial cancers. Responses were observed in patients with multiple molecular aberrations. Clinical Trails Included: NCT01197170 PMID:24912489

  10. Over-expression of HSPA12B protects mice against myocardium ischemic/reperfusion injury through a PPARγ-dependent PI3K/Akt/eNOS pathway

    PubMed Central

    Sun, Yanjun; Ye, Lincai; Jiang, Chuan; Jiang, Jun; Hong, Haifa; Qiu, Lisheng

    2015-01-01

    Acute myocardial ischemia/reperfusion (MIR) injury leads to severe arrhythmias and a high lethality. We aim to determine the effect of heat shock protein A12B (HSPA12B), a newly discovered member of the Hsp70 family, on heart injury parameters following MIR surgery. We used HSPA12B transgenic mice to determine its effects on heart function parameters, infarct size and cellular apoptosis following MIR surgery. Proinflammatory cytokines, oxidative products and anti-oxidative enzymes in the myocardium were measured to evaluate the anti-inflammatory and anti-oxidative effects of HSPA12B over-expression. The role of PPARs/eNOS/PI3k/Akt pathway was investigated using their inhibitors. The alteration of hemodynamic parameters, histopathological, apoptotic and infarct size caused by MIR was greatly attenuated in HSPA12B over-expressed mice. HSPA12B also greatly mitigated the inflammatory response, demonstrated by the decrease in the levels of IL-1β, IL-6, TNF-a and MPO. Anti-oxidative enzymes (SOD, Catalase and GPx) were restored by HSPA12B; oxidative products (8-OHdG, MDA and protein carbonyl) were decreased. HSPA12B activated the PPARγ-dependent eNOS/PI3k/Akt pathway, and the influence of HSPA12B on cardiac function was reversed by the inhibitors of eNOS, PPARγ, Akt and PI3K. Our results present a novel signaling mechanism that HSPA12B protects MIR injury through a PPARγ-dependent PI3K/Akt/eNOS pathway. PMID:26885270

  11. Twist promotes reprogramming of glucose metabolism in breast cancer cells through PI3K/AKT and p53 signaling pathways.

    PubMed

    Yang, Li; Hou, Yixuan; Yuan, Jie; Tang, Shifu; Zhang, Hailong; Zhu, Qing; Du, Yan-e; Zhou, Mingli; Wen, Siyang; Xu, Liyun; Tang, Xi; Cui, Xiaojiang; Liu, Manran

    2015-09-22

    Twist, a key regulator of epithelial-mesenchymal transition (EMT), plays an important role in the development of a tumorigenic phenotype. Energy metabolism reprogramming (EMR), a newly discovered hallmark of cancer cells, potentiates cancer cell proliferation, survival, and invasion. Currently little is known about the effects of Twist on tumor EMR. In this study, we found that glucose consumption and lactate production were increased and mitochondrial mass was decreased in Twist-overexpressing MCF10A mammary epithelial cells compared with vector-expressing MCF10A cells. Moreover, these Twist-induced phenotypic changes were augmented by hypoxia. The expression of some glucose metabolism-related genes such as PKM2, LDHA, and G6PD was also found to be upregulated. Mechanistically, activated β1-integrin/FAK/PI3K/AKT/mTOR and suppressed P53 signaling were responsible for the observed EMR. Knockdown of Twist reversed the effects of Twist on EMR in Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Furthermore, blockage of the β1-integrin/FAK/PI3K/AKT/mTOR pathway by siRNA or specific chemical inhibitors, or rescue of p53 activation can partially reverse the switch of glucose metabolism and inhibit the migration of Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Thus, our data suggest that Twist promotes reprogramming of glucose metabolism in MCF10A-Twist cells and Twist-positive breast cancer cells via activation of the β1-integrin/FAK/PI3K/AKT/mTOR pathway and inhibition of the p53 pathway. Our study provides new insight into EMR. PMID:26342198

  12. Twist promotes reprogramming of glucose metabolism in breast cancer cells through PI3K/AKT and p53 signaling pathways.

    PubMed

    Yang, Li; Hou, Yixuan; Yuan, Jie; Tang, Shifu; Zhang, Hailong; Zhu, Qing; Du, Yan-e; Zhou, Mingli; Wen, Siyang; Xu, Liyun; Tang, Xi; Cui, Xiaojiang; Liu, Manran

    2015-09-22

    Twist, a key regulator of epithelial-mesenchymal transition (EMT), plays an important role in the development of a tumorigenic phenotype. Energy metabolism reprogramming (EMR), a newly discovered hallmark of cancer cells, potentiates cancer cell proliferation, survival, and invasion. Currently little is known about the effects of Twist on tumor EMR. In this study, we found that glucose consumption and lactate production were increased and mitochondrial mass was decreased in Twist-overexpressing MCF10A mammary epithelial cells compared with vector-expressing MCF10A cells. Moreover, these Twist-induced phenotypic changes were augmented by hypoxia. The expression of some glucose metabolism-related genes such as PKM2, LDHA, and G6PD was also found to be upregulated. Mechanistically, activated β1-integrin/FAK/PI3K/AKT/mTOR and suppressed P53 signaling were responsible for the observed EMR. Knockdown of Twist reversed the effects of Twist on EMR in Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Furthermore, blockage of the β1-integrin/FAK/PI3K/AKT/mTOR pathway by siRNA or specific chemical inhibitors, or rescue of p53 activation can partially reverse the switch of glucose metabolism and inhibit the migration of Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Thus, our data suggest that Twist promotes reprogramming of glucose metabolism in MCF10A-Twist cells and Twist-positive breast cancer cells via activation of the β1-integrin/FAK/PI3K/AKT/mTOR pathway and inhibition of the p53 pathway. Our study provides new insight into EMR.

  13. Agmatine Reduces Lipopolysaccharide-Mediated Oxidant Response via Activating PI3K/Akt Pathway and Up-Regulating Nrf2 and HO-1 Expression in Macrophages

    PubMed Central

    Chai, Jianshen; Luo, Li; Hou, Fengyan; Fan, Xia; Yu, Jing; Ma, Wei; Tang, Wangqi; Yang, Xue; Zhu, Junyu; Kang, Wenyuan; Yan, Jun; Liang, Huaping

    2016-01-01

    Macrophages are key responders of inflammation and are closely related with oxidative stress. Activated macrophages can enhance oxygen depletion, which causes an overproduction of reactive oxygen species (ROS) and leads to further excessive inflammatory response and tissue damage. Agmatine, an endogenous metabolite of L-arginine, has recently been shown to have neuroprotective effects based on its antioxidant properties. However, the antioxidant effects of agmatine in peripheral tissues and cells, especially macrophages, remain unclear. In this study we explored the role of agmatine in mediating antioxidant effects in RAW 264.7 cells and studied its antioxidant mechanism. Our data demonstrate that agmatine is an activator of Nrf2 signaling that markedly enhances Nrf2 nuclear translocation, increases nuclear Nrf2 protein level, up-regulates the expression of the Nrf2 downstream effector HO-1, and attenuates ROS generation induced by Lipopolysaccharide (LPS). We further demonstrated that the agmatine-induced activation of Nrf2 is likely through the PI3K/Akt pathway. LY294002, a specific PI3K/Akt inhibitor, abolished agmatine-induced HO-1 up-regulation and ROS suppression significantly. Inhibiting HO-1 pathway significantly attenuated the antioxidant effect of agmatine which the products of HO-1 enzymatic activity contributed to. Furthermore, the common membrane receptors of agmatine were evaluated, revealing that α2-adrenoceptor, I1-imidazoline receptor or I2-imidazoline receptor are not required by the antioxidant properties of agmatine. Taken together, our findings revealed that agmatine has antioxidant activity against LPS-induced ROS accumulation in RAW 264.7 cells involving HO-1 expression induced by Nrf2 via PI3K/Akt pathway activation. PMID:27685463

  14. IL-7 splicing variant IL-7{delta}5 induces human breast cancer cell proliferation via activation of PI3K/Akt pathway

    SciTech Connect

    Pan, Deshun; Liu, Bing; Jin, Xiaobao; Zhu, Jiayong

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer This study confirms the role of IL-7{delta}5 in breast cancer cell proliferation. Black-Right-Pointing-Pointer IL-7{delta}5 promotes breast cancer cell proliferation and cell cycle progression. Black-Right-Pointing-Pointer IL-7{delta}5 promotes cell proliferation via activation of PI3K/Akt pathway. -- Abstract: Various tumor cells express interleukin 7 (IL-7) and IL-7 variants. IL-7 has been confirmed to stimulate solid tumor cell proliferation. However, the effect of IL-7 variants on tumor cell proliferation remains unclear. In this study, we evaluated the role of IL-7{delta}5 (an IL-7 variant lacking exon 5) on proliferation and cell cycle progression of human MDA-MB-231 and MCF-7 breast cancer cells. The results showed that IL-7{delta}5 promoted cell proliferation and cell cycle progression from G1 phase to G2/M phase, associated with upregulation of cyclin D1 expression and the downregulation of p27{sup kip1} expression. Mechanistically, we found that IL-7{delta}5 induced the activation of Akt. Inhibition of PI3K/Akt pathway by LY294002 reversed the proliferation and cell cycle progression of MDA-MB-231 and MCF-7 cells induced by IL-7{delta}5. In conclusion, our findings demonstrate that IL-7{delta}5 variant induces human breast cancer cell proliferation and cell cycle progression via activation of PI3K/Akt pathway. Thus, IL-7{delta}5 may be a potential target for human breast cancer therapeutics intervention.

  15. Twist promotes reprogramming of glucose metabolism in breast cancer cells through PI3K/AKT and p53 signaling pathways

    PubMed Central

    Yuan, Jie; Tang, Shifu; Zhang, Hailong; Zhu, Qing; Du, Yan-e; Zhou, Mingli; Wen, Siyang; Xu, Liyun; Tang, Xi; Cui, Xiaojiang; Liu, Manran

    2015-01-01

    Twist, a key regulator of epithelial-mesenchymal transition (EMT), plays an important role in the development of a tumorigenic phenotype. Energy metabolism reprogramming (EMR), a newly discovered hallmark of cancer cells, potentiates cancer cell proliferation, survival, and invasion. Currently little is known about the effects of Twist on tumor EMR. In this study, we found that glucose consumption and lactate production were increased and mitochondrial mass was decreased in Twist-overexpressing MCF10A mammary epithelial cells compared with vector-expressing MCF10A cells. Moreover, these Twist-induced phenotypic changes were augmented by hypoxia. The expression of some glucose metabolism-related genes such as PKM2, LDHA, and G6PD was also found to be upregulated. Mechanistically, activated β1-integrin/FAK/PI3K/AKT/mTOR and suppressed P53 signaling were responsible for the observed EMR. Knockdown of Twist reversed the effects of Twist on EMR in Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Furthermore, blockage of the β1-integrin/FAK/PI3K/AKT/mTOR pathway by siRNA or specific chemical inhibitors, or rescue of p53 activation can partially reverse the switch of glucose metabolism and inhibit the migration of Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Thus, our data suggest that Twist promotes reprogramming of glucose metabolism in MCF10A-Twist cells and Twist-positive breast cancer cells via activation of the β1-integrin/FAK/PI3K/AKT/mTOR pathway and inhibition of the p53 pathway. Our study provides new insight into EMR. PMID:26342198

  16. Quercetin Protects against Okadaic Acid-Induced Injury via MAPK and PI3K/Akt/GSK3β Signaling Pathways in HT22 Hippocampal Neurons.

    PubMed

    Jiang, Wei; Luo, Tao; Li, Sheng; Zhou, Yue; Shen, Xiu-Yin; He, Feng; Xu, Jie; Wang, Hua-Qiao

    2016-01-01

    Increasing evidence shows that oxidative stress and the hyperphosphorylation of tau protein play essential roles in the progression of Alzheimer's disease (AD). Quercetin is a major flavonoid that has anti-oxidant, anti-cancer and anti-inflammatory properties. We investigated the neuroprotective effects of quercetin to HT22 cells (a cell line from mouse hippocampal neurons). We found that Okadaic acid (OA) induced the hyperphosphorylation of tau protein at Ser199, Ser396, Thr205, and Thr231 and produced oxidative stress to the HT22 cells. The oxidative stress suppressed the cell viability and decreased the levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD), mitochondria membrane potential (MMP) and Glutathione peroxidase (GSH-Px). It up-regulated malondialdehyde (MDA) production and intracellular reactive oxygen species (ROS). In addition, phosphoinositide 3 kinase/protein kinase B/Glycogen synthase kinase3β (PI3K/Akt/GSK3β) and mitogen activated protein kinase (MAPK) were also involved in this process. We found that pre-treatment with quercetin can inhibited OA-induced the hyperphosphorylation of tau protein and oxidative stress. Moreover, pre-treatment with quercetin not only inhibited OA-induced apoptosis via the reduction of Bax, and up-regulation of cleaved caspase 3, but also via the inhibition of PI3K/Akt/GSK3β, MAPKs and activation of NF-κB p65. Our findings suggest the therapeutic potential of quercetin to treat AD. PMID:27050422

  17. Quercetin Protects against Okadaic Acid-Induced Injury via MAPK and PI3K/Akt/GSK3β Signaling Pathways in HT22 Hippocampal Neurons

    PubMed Central

    Li, Sheng; Zhou, Yue; Shen, Xiu-Yin; He, Feng; Xu, Jie; Wang, Hua-Qiao

    2016-01-01

    Increasing evidence shows that oxidative stress and the hyperphosphorylation of tau protein play essential roles in the progression of Alzheimer’s disease (AD). Quercetin is a major flavonoid that has anti-oxidant, anti-cancer and anti-inflammatory properties. We investigated the neuroprotective effects of quercetin to HT22 cells (a cell line from mouse hippocampal neurons). We found that Okadaic acid (OA) induced the hyperphosphorylation of tau protein at Ser199, Ser396, Thr205, and Thr231 and produced oxidative stress to the HT22 cells. The oxidative stress suppressed the cell viability and decreased the levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD), mitochondria membrane potential (MMP) and Glutathione peroxidase (GSH-Px). It up-regulated malondialdehyde (MDA) production and intracellular reactive oxygen species (ROS). In addition, phosphoinositide 3 kinase/protein kinase B/Glycogen synthase kinase3β (PI3K/Akt/GSK3β) and mitogen activated protein kinase (MAPK) were also involved in this process. We found that pre-treatment with quercetin can inhibited OA-induced the hyperphosphorylation of tau protein and oxidative stress. Moreover, pre-treatment with quercetin not only inhibited OA-induced apoptosis via the reduction of Bax, and up-regulation of cleaved caspase 3, but also via the inhibition of PI3K/Akt/GSK3β, MAPKs and activation of NF-κB p65. Our findings suggest the therapeutic potential of quercetin to treat AD. PMID:27050422

  18. Tianeptine sodium salt suppresses TNF-α-induced expression of matrix metalloproteinase-9 in human carcinoma cells via suppression of the PI3K/Akt-mediated NF-κB pathway.

    PubMed

    Jayasooriya, Rajapaksha Gedara Prasad Tharanga; Dilshara, Matharage Gayani; Choi, Yung Hyun; Moon, Sung-Kwon; Kim, Wun-Jae; Kim, Gi-Young

    2014-09-01

    Tianeptine sodium salt (TSS) is a selective facilitator of serotonin, but there are no reports regarding anti-invasive effects of TSS. Therefore, we investigated the effect of TSS on the expression of matrix metalloproteinase-9 (MMP-9) and invasion in three different human carcinoma cell lines. Our findings showed that MMP-9 activity was significantly increased in response to tumor necrosis factor-α (TNF-α), and that TSS reduced TNF-α-induced MMP-9 activity in a dose-dependent manner. TSS also downregulated both MMP-9 expression and TNF-α-induced MMP-9 promoter activity. Using a matrigel invasion assay, we showed that TSS significantly attenuated invasive rates in TNF-α-stimulated LNCaP prostate carcinoma cells. Furthermore, TSS suppressed TNF-α-induced NF-κB activity, which is a potential transcriptional factor for regulating many invasive genes, including MMP-9, by suppressing IκB degradation and nuclear translocation of NF-κB subunits in LNCaP prostate carcinoma cells. TSS also downregulated TNF-α-induced phosphorylation of phosphatidyl-inositol 3 kinase (PI3K) and Akt, and a selective PI3K/Akt inhibitor, LY294002, diminished TNF-α-induced NF-κB activation followed by levels of MMP-9, suggesting that TSS also reduces MMP-9 expression by inhibiting the PI3K/Akt-mediated NF-κB pathway. These results indicate that TSS is a potential anti-invasive agent by suppression of TNF-α-induced MMP-9 expression via inhibition of PI3K/Akt-mediated NF-κB activity.

  19. Tianeptine sodium salt suppresses TNF-α-induced expression of matrix metalloproteinase-9 in human carcinoma cells via suppression of the PI3K/Akt-mediated NF-κB pathway.

    PubMed

    Jayasooriya, Rajapaksha Gedara Prasad Tharanga; Dilshara, Matharage Gayani; Choi, Yung Hyun; Moon, Sung-Kwon; Kim, Wun-Jae; Kim, Gi-Young

    2014-09-01

    Tianeptine sodium salt (TSS) is a selective facilitator of serotonin, but there are no reports regarding anti-invasive effects of TSS. Therefore, we investigated the effect of TSS on the expression of matrix metalloproteinase-9 (MMP-9) and invasion in three different human carcinoma cell lines. Our findings showed that MMP-9 activity was significantly increased in response to tumor necrosis factor-α (TNF-α), and that TSS reduced TNF-α-induced MMP-9 activity in a dose-dependent manner. TSS also downregulated both MMP-9 expression and TNF-α-induced MMP-9 promoter activity. Using a matrigel invasion assay, we showed that TSS significantly attenuated invasive rates in TNF-α-stimulated LNCaP prostate carcinoma cells. Furthermore, TSS suppressed TNF-α-induced NF-κB activity, which is a potential transcriptional factor for regulating many invasive genes, including MMP-9, by suppressing IκB degradation and nuclear translocation of NF-κB subunits in LNCaP prostate carcinoma cells. TSS also downregulated TNF-α-induced phosphorylation of phosphatidyl-inositol 3 kinase (PI3K) and Akt, and a selective PI3K/Akt inhibitor, LY294002, diminished TNF-α-induced NF-κB activation followed by levels of MMP-9, suggesting that TSS also reduces MMP-9 expression by inhibiting the PI3K/Akt-mediated NF-κB pathway. These results indicate that TSS is a potential anti-invasive agent by suppression of TNF-α-induced MMP-9 expression via inhibition of PI3K/Akt-mediated NF-κB activity. PMID:25168152

  20. Jolkinolide B induces apoptosis in MCF-7 cells through inhibition of the PI3K/Akt/mTOR signaling pathway.

    PubMed

    Xu, Hui-Yu; Chen, Zhi-Wei; Hou, Jin-Cai; Du, Feng-Xia; Liu, Ji-Cheng

    2013-01-01

    The aim of this study was to explore the molecular mechanisms of jolkinolide B (JB), which is extracted from the root of Euphorbia fischeriana Steud. In this study, we found that JB, a diterpenoid from the traditional Chinese medicinal herb, strongly inhibited the PI3K/Akt/mTOR signaling pathway. Furthermore, we evaluated the effects of JB on the proliferation and apoptosis of MCF-7 human breast cancer cells. Our results showed significant induction of apoptosis in MCF-7 cells incubated with JB. The viability of the MCF-7 cells was assessed by MTT assay. Flow cytometry was used to detect apoptosis and cell cycle analysis. Transmission electron microscopy (TEM) analysis was used to observe cell morphology. MCF-7 cells were subcutaneously inoculated into nude mice to study the in vivo antitumor effects of JB. The growth of MCF-7 cells was inhibited and arrested in the S phase by JB. The data showed significantly decreased tumor volume and weight in nude mice inoculated with MCF-7 cells. In addition, treatment with JB was able to induce downregulation of cyclinD1, cyclinE, mTOR, p-PI3K and p-Akt, and upregulation of PTEN and p-eIF4E. Collectively, JB-induced apoptosis of MCF-7 cells occurs through the PI3K/Akt/mTOR signaling pathway. Furthermore, the PI3K/Akt signaling cascade plays a role in the induction of apoptosis in JB-treated cells. These observations suggest that JB may have therapeutic applications in the treatment of cancer.

  1. Osseointegration of chitosan coated porous titanium alloy implant by reactive oxygen species-mediated activation of the PI3K/AKT pathway under diabetic conditions.

    PubMed

    Li, Xiang; Ma, Xiang-Yu; Feng, Ya-Fei; Ma, Zhen-Sheng; Wang, Jian; Ma, Tian-Cheng; Qi, Wei; Lei, Wei; Wang, Lin

    2015-01-01

    Chitosan coated porous titanium alloy implant (CTI) is demonstrated a promising approach to improve osseointegration capacity of pure porous titanium alloy implant (TI). Since chitosan has been demonstrated to exhibit antioxidant activity, we propose CTI may ameliorate the ROS overproduction, thus reverse the poor osseointegration under diabetic conditions, and investigate the underlying mechanisms. Primary rat osteoblasts incubated on the TI and the CTI were subjected to normal serum (NS), diabetic serum (DS), DS + NAC (a potent ROS inhibitor) and DS + LY294002 (a PI3K/AKT-specific inhibitor). In vivo study was performed on diabetic sheep implanted with TI or CTI into the bone defects on crista iliaca. Results showed that diabetes-induced ROS overproduction led to osteoblast dysfunction and apoptosis, concomitant with the inhibition of AKT in osteoblasts on the TI substrate. While CTI stimulated AKT phosphorylation through ROS attenuation, thus reversed osteoblast dysfunction evidenced by improved osteoblast adhesion, increased proliferation and ALP activity, and decreased cytotoxicity and apoptotic rate, which exerted same effect to NAC treatment on the TI. These effects were further confirmed by the improved osseointegration within the CTI in vivo evidenced by Micro-CT and histological examinations. In addition, the aforementioned promotive effects afforded by CTI were abolished by blocking PI3K/AKT pathway with addition of LY294002. These results demonstrate that the chitosan coating markedly ameliorates diabetes-induced impaired bio-performance of TI via ROS-mediated reactivation of PI3K/AKT pathway, which elicits a new surface functionalization strategy for better clinical performance of titanium implant in diabetic patients.

  2. Pyrroloquinoline quinone inhibits oxygen/glucose deprivation-induced apoptosis by activating the PI3K/AKT pathway in cardiomyocytes.

    PubMed

    Xu, Feng; Yu, Haixia; Liu, Jinyao; Cheng, Lu

    2014-01-01

    The purposes of this study were to examine the protective effect of pyrroloquinoline quinone (PQQ) on oxygen/glucose deprivation (OGD)-induced injury to H9C2 rat cardiomyocytes and to investigate the mechanism. Using H9C2 cells cultured in vitro, we examined changes in cell viability with an MTT assay at 12, 24, and 48 h after injury induced by OGD. Various concentrations of PQQ (1, 10, and 100 μM) were added, and the effect of PQQ on cell viability after OGD was assessed using the MTT assay. Thus, the optimal concentration of PQQ for the protection of cardiomyocytes against oxygen and glucose deprivation injury was determined. We also used flow cytometry analysis to examine the effect of PQQ on H9C2 cells with OGD-induced injury. The molecular probe 2',7'-dichlorofluorescin diacetate was used to label the H9C2 cells, and flow cytometry was used to detect the effect of PQQ on reactive oxygen species (ROS) content. After labeling the H9C2 cells using a mitochondrial green fluorescent probe (Mito-Tracker Green), we measured the change in the mitochondrial content of PQQ-treated H9C2 cells. Western blotting was used to examine the effect of PQQ on the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in the H9C2 cells. The results of the MTT assay showed that 48 h of OGD significantly injured the H9C2 cells (p < 0.01) and that treatment with 100 μM PQQ effectively decreased the level of OGD-induced injury (p < 0.01). The results of the flow cytometry analysis showed that PQQ significantly reduced apoptosis in H9C2 cells subjected to OGD (p < 0.05). In addition, OGD significantly increased the ROS level in H9C2 cells (p < 0.01), and PQQ significantly inhibited this increase (p < 0.05). The results of the Mito-Tracker Green staining suggested that PQQ effectively inhibited the decrease in mitochondrial content caused by OGD (p < 0.05). Western blot analysis showed that PQQ partially reversed the decrease in Akt phosphorylation that was caused by OGD (p

  3. Gedunin abrogates aldose reductase, PI3K/Akt/mToR, and NF-κB signaling pathways to inhibit angiogenesis in a hamster model of oral carcinogenesis.

    PubMed

    Kishore T, Kranthi Kiran; Ganugula, Raghu; Gade, Deepak Reddy; Reddy, Geereddy Bhanuprakash; Nagini, Siddavaram

    2016-02-01

    Aberrant activation of oncogenic signaling pathways plays a central role in tumor development and progression. The aim of this present study was to investigate the chemopreventive effects of the neem limonoid gedunin in the hamster model of oral cancer based on its ability to modulate aldose reductase (AR), phosphatidyl inositol-3-kinase (PI3K)/Akt, and nuclear factor kappa B (NF-κB) pathways to block angiogenesis. Administration of gedunin suppressed the development of HBP carcinomas by inhibiting PI3K/Akt and NF-κB pathways through the inactivation of Akt and inhibitory kappa B kinase (IKK), respectively. Immunoblot and molecular docking interactions revealed that inhibition of these signaling pathways may be mediated via inactivation of AR by gedunin. Gedunin blocked angiogenesis by downregulating the expression of miR-21 and the pro-angiogenic factors vascular endothelial growth factor and hypoxia inducible factor-1 alpha (HIF-1α). In conclusion, the results of the present study provide compelling evidence that gedunin prevents progression of hamster buccal pouch (HBP) carcinomas via inhibition of the kinases Akt, IKK, and AR, and the oncogenic transcription factors NF-κB and HIF-1α to block angiogenesis. PMID:26342697

  4. Arctigenin, a Potent Ingredient of Arctium lappa L., Induces Endothelial Nitric Oxide Synthase and Attenuates Subarachnoid Hemorrhage-Induced Vasospasm through PI3K/Akt Pathway in a Rat Model.

    PubMed

    Chang, Chih-Zen; Wu, Shu-Chuan; Chang, Chia-Mao; Lin, Chih-Lung; Kwan, Aij-Lie

    2015-01-01

    Upregulation of protein kinase B (PKB, also known as Akt) is observed within the cerebral arteries of subarachnoid hemorrhage (SAH) animals. This study is of interest to examine Arctigenin, a potent antioxidant, on endothelial nitric oxide synthase (eNOS) and Akt pathways in a SAH in vitro study. Basilar arteries (BAs) were obtained to examine phosphatidylinositol-3-kinase (PI3K), phospho-PI3K, Akt, phospho-Akt (Western blot) and morphological examination. Endothelins (ETs) and eNOS evaluation (Western blot and immunostaining) were also determined. Arctigenin treatment significantly alleviates disrupted endothelial cells and tortured internal elastic layer observed in the SAH groups (p < 0.01). The reduced eNOS protein and phospho-Akt expression in the SAH groups were relieved by the treatment of Arctigenin (p < 0.01). This result confirmed that Arctigenin might exert dural effects in preventing SAH-induced vasospasm through upregulating eNOS expression via the PI3K/Akt signaling pathway and attenuate endothelins after SAH. Arctigenin shows therapeutic promise in the treatment of cerebral vasospasm following SAH.

  5. Arctigenin, a Potent Ingredient of Arctium lappa L., Induces Endothelial Nitric Oxide Synthase and Attenuates Subarachnoid Hemorrhage-Induced Vasospasm through PI3K/Akt Pathway in a Rat Model

    PubMed Central

    Chang, Chih-Zen; Wu, Shu-Chuan; Chang, Chia-Mao; Lin, Chih-Lung; Kwan, Aij-Lie

    2015-01-01

    Upregulation of protein kinase B (PKB, also known as Akt) is observed within the cerebral arteries of subarachnoid hemorrhage (SAH) animals. This study is of interest to examine Arctigenin, a potent antioxidant, on endothelial nitric oxide synthase (eNOS) and Akt pathways in a SAH in vitro study. Basilar arteries (BAs) were obtained to examine phosphatidylinositol-3-kinase (PI3K), phospho-PI3K, Akt, phospho-Akt (Western blot) and morphological examination. Endothelins (ETs) and eNOS evaluation (Western blot and immunostaining) were also determined. Arctigenin treatment significantly alleviates disrupted endothelial cells and tortured internal elastic layer observed in the SAH groups (p < 0.01). The reduced eNOS protein and phospho-Akt expression in the SAH groups were relieved by the treatment of Arctigenin (p < 0.01). This result confirmed that Arctigenin might exert dural effects in preventing SAH-induced vasospasm through upregulating eNOS expression via the PI3K/Akt signaling pathway and attenuate endothelins after SAH. Arctigenin shows therapeutic promise in the treatment of cerebral vasospasm following SAH. PMID:26539501

  6. Arctigenin, a Potent Ingredient of Arctium lappa L., Induces Endothelial Nitric Oxide Synthase and Attenuates Subarachnoid Hemorrhage-Induced Vasospasm through PI3K/Akt Pathway in a Rat Model.

    PubMed

    Chang, Chih-Zen; Wu, Shu-Chuan; Chang, Chia-Mao; Lin, Chih-Lung; Kwan, Aij-Lie

    2015-01-01

    Upregulation of protein kinase B (PKB, also known as Akt) is observed within the cerebral arteries of subarachnoid hemorrhage (SAH) animals. This study is of interest to examine Arctigenin, a potent antioxidant, on endothelial nitric oxide synthase (eNOS) and Akt pathways in a SAH in vitro study. Basilar arteries (BAs) were obtained to examine phosphatidylinositol-3-kinase (PI3K), phospho-PI3K, Akt, phospho-Akt (Western blot) and morphological examination. Endothelins (ETs) and eNOS evaluation (Western blot and immunostaining) were also determined. Arctigenin treatment significantly alleviates disrupted endothelial cells and tortured internal elastic layer observed in the SAH groups (p < 0.01). The reduced eNOS protein and phospho-Akt expression in the SAH groups were relieved by the treatment of Arctigenin (p < 0.01). This result confirmed that Arctigenin might exert dural effects in preventing SAH-induced vasospasm through upregulating eNOS expression via the PI3K/Akt signaling pathway and attenuate endothelins after SAH. Arctigenin shows therapeutic promise in the treatment of cerebral vasospasm following SAH. PMID:26539501

  7. Deuterohemin-AlaHisLys mitigates the symptoms of rats with non-insulin dependent diabetes mellitus by scavenging reactive oxygen species and activating the PI3-K/AKT signal transduction pathway.

    PubMed

    Lei, Liyan; Zhang, Guangji; Li, Pengfei; Zhang, Yuan; Guo, Youming; Zhang, Wenqi; Zhang, Wenbo; Hu, Bing; Wang, Liping

    2014-09-01

    Damage to pancreatic β-cells plays an important role in the development of type 2 diabetes, and oxidative stress is a likely contributor. In the present study, we investigated the effect of deuterohemin-AlaHisLys (DhHP-3), a microperoxidase-11 mimic, on rats with non-insulin dependent diabetes mellitus and examined the action mechanisms of DhHP-3. The induced hyperglycemia, glucose intolerance, and insulin resistance in diabetic rats were associated with increased oxidative stress and damage to pancreatic islets. DhHP-3 (3 mg/kg) ameliorated hyperglycemia and insulin resistance, protected pancreas islet, decreased the content of malondialdehyde, and increased the activity of superoxide dismutase in plasma and pancreatic tissue by reducing ROS levels. Furthermore, DhHP-3 stimulated the proliferation of INS-1 cells and inhibited apoptosis by activating the phosphatidylinositol 3-kinase/protein kinase B (PI3-K/AKT) signaling pathway. Our results demonstrated for the first time that DhHP-3 decreased blood glucose level in rats with non-insulin dependent diabetes mellitus, scavenged reactive oxygen species, activated the PI3-K/AKT signaling pathway, and protected pancreatic β-cells against apoptosis.

  8. Short-term hypoxia enhances the migratory capability of dendritic cell through HIF-1α and PI3K/Akt pathway.

    PubMed

    Filippi, Irene; Morena, Emilia; Aldinucci, Carlo; Carraro, Fabio; Sozzani, Silvano; Naldini, Antonella

    2014-12-01

    Hypoxia represents an inadequate oxygen supply to tissues, which can modulate cell functions, primarily through the hypoxia-inducible transcription factor HIF-1α. Dendritic cells (DC) are professional antigen-presenting cells and their migration maybe affected by hypoxia, since the local microenvironment in lymphoid organs, as well as in inflamed and tumor tissues, is characterized by low oxygen tensions. In this study we observed an enhanced migratory capability of human monocyte-derived DC, using in vitro migration assays performed under hypoxic conditions. Such enhancement was independent on either the chemoattractants involved or the maturation level of DC. However, HIF-1α appeared to be crucial for the migration only of immature DC and not for mature DC under hypoxia, as indicated by HIF-1α siRNA approaches. Furthermore, we observed that while Akt phosphorylation was enhanced in both immature and mature DC exposed to hypoxia, other signaling pathways, such as p38 and p42/p44 MAPK, were differently affected during hypoxic treatment. More interestingly, aspecific and specific inhibition of PI3K/Akt indicated that such pathway was relevant for the migration of both immature and matured DC under hypoxia, even when DC were transfected with HIF-1α siRNA. Our results indicate that, besides HIF-1α, several other pathways, including PI3K/Akt, may be involved in the response to hypoxia of immature and, more specifically, of mature DC to sustain their trafficking and functions within hypoxic microenvironments.

  9. Neuroprotective Effects of Salidroside in the MPTP Mouse Model of Parkinson's Disease: Involvement of the PI3K/Akt/GSK3β Pathway

    PubMed Central

    He, Hong; Song, Hujie; Zhao, Junjie; Li, Tao; Wu, Leitao

    2016-01-01

    The degenerative loss through apoptosis of dopaminergic neurons in the substantia nigra pars compacta plays a primary role in the progression of Parkinson's disease (PD). Our in vitro experiments suggested that salidroside (Sal) could protect against 1-methyl-4-phenylpyridine-induced cell apoptosis in part by regulating the PI3K/Akt/GSK3β pathway. The current study aims to increase our understanding of the protective mechanisms of Sal in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropypridine- (MPTP-) induced PD mouse model. We found that pretreatment with Sal could protect against MPTP-induced increase of the time of turning downwards and climbing down to the floor. Sal also prevented MPTP-induced decrease of locomotion frequency and the increase of the immobile time. Sal provided a protection of in MPTP-induced loss of tyrosine hydroxylase-positive neurons in SNpc and the level of DA, DOPAC, and HVA in the striatum. Furthermore, Sal could increase the phosphorylation level of Akt and GSK3β, upregulate the ratio of Bcl-2/Bax, and inhibit the activation of caspase-3, caspase-6, and caspase-9. These results show that Sal prevents the loss of dopaminergic neurons and the PI3K/Akt/GSK3β pathway signaling pathway may have mediated the protection of Sal against MPTP, suggesting that Sal may be a potential candidate in neuroprotective treatment for PD. PMID:27738547

  10. The PI3K/Akt pathway: recent progress in the development of ATP-competitive and allosteric Akt kinase inhibitors.

    PubMed

    Lindsley, Craig W; Barnett, Stanley F; Layton, Mark E; Bilodeau, Mark T

    2008-02-01

    This article describes recent advances in the development and biological evaluation of allosteric and ATP-competitive small molecule inhibitors for the serine/threonine kinase Akt (protein kinase B, PKB). Unregulated activation of the PI3K/Akt/PTEN pathway is a prominent feature of many human cancers and Akt is over-expressed or activated in all major cancers making Akt an exciting new target for cancer therapy. The development of Akt inhibitors has been complicated and hampered by the presence of three Akt isozymes, (Akt1, Akt2 and Akt3) which differ in function and tissue distribution, as well as a lack of Akt specific inhibitors. In the past 18 months, a large number of reports have appeared describing the discovery and development of allosteric Akt kinase inhibitors and classical ATP-competitive Akt kinase inhibitors. This review will discuss the PI3K/Akt/PTEN pathway, allosteric and ATP-competitive Akt kinase inhibitors, their biological evaluation and progress towards target validation.

  11. The promotion of angiogenesis induced by three-dimensional porous beta-tricalcium phosphate scaffold with different interconnection sizes via activation of PI3K/Akt pathways

    PubMed Central

    Xiao, Xin; Wang, Wei; Liu, Dong; Zhang, Haoqiang; Gao, Peng; Geng, Lei; Yuan, Yulin; Lu, Jianxi; Wang, Zhen

    2015-01-01

    The porous architectural characteristics of biomaterials play an important role in scaffold revascularization. However, no consensus exists regarding optimal interconnection sizes for vascularization and its scaffold bioperformance with different interconnection sizes. Therefore, a series of disk-type beta-tricalcium phosphates with the same pore sizes and variable interconnections were produced to evaluate how the interconnection size influenced biomaterial vascularization in vitro and in vivo. We incubated human umbilical vein endothelial cells on scaffolds with interconnections of various sizes. Results showed that scaffolds with a 150 μm interconnection size ameliorated endothelial cell function evidenced by promoting cell adhesion and migration, increasing cell proliferation and enhancing expression of platelet-endothelial cell adhesion molecules and vascular endothelial growth factor. In vivo study was performed on rabbit implanted with scaffolds into the bone defect on femoral condyles. Implantation with scaffolds with 150 μm interconnection size significantly improved neovascularization as shown by micro-CT as compared to scaffolds with 100 and 120 μm interconnection sizes. Moreover, the aforementioned positive effects were abolished by blocking PI3K/Akt/eNOS pathway with LY-294002. Our study explicitly demonstrates that the scaffold with 150 μm interconnection size improves neovascularization via the PI3K/Akt pathway and provides a target for biomaterial inner structure modification to attain improved clinical performance in implant vascularization. PMID:25797242

  12. Glimepiride Promotes Osteogenic Differentiation in Rat Osteoblasts via the PI3K/Akt/eNOS Pathway in a High Glucose Microenvironment

    PubMed Central

    Xiong, Wei; Tan, Baosheng; Geng, Wei; Li, Jun; Liu, Hongchen

    2014-01-01

    Our previous studies demonstrated that glimepiride enhanced the proliferation and differentiation of osteoblasts and led to activation of the PI3K/Akt pathway. Recent genetic evidence shows that endothelial nitric oxide synthase (eNOS) plays an important role in bone homeostasis. In this study, we further elucidated the roles of eNOS, PI3K and Akt in bone formation by osteoblasts induced by glimepiride in a high glucose microenvironment. We demonstrated that high glucose (16.5 mM) inhibits the osteogenic differentiation potential and proliferation of rat osteoblasts. Glimepiride activated eNOS expression in rat osteoblasts cultured with two different concentrations of glucose. High glucose-induced osteogenic differentiation was significantly enhanced by glimepiride. Down-regulation of PI3K P85 levels by treatment with LY294002 (a PI3K inhibitor) led to suppression of P-eNOS and P-AKT expression levels, which in turn resulted in inhibition of RUNX2, OCN and ALP mRNA expression in osteoblasts induced by glimepiride at both glucose concentrations. ALP activity was partially inhibited by 10 µM LY294002. Taken together, our results demonstrate that glimepiride-induced osteogenic differentiation of osteoblasts occurs via eNOS activation and is dependent on the PI3K/Akt signaling pathway in a high glucose microenvironment. PMID:25391146

  13. Glimepiride promotes osteogenic differentiation in rat osteoblasts via the PI3K/Akt/eNOS pathway in a high glucose microenvironment.

    PubMed

    Ma, Pan; Gu, Bin; Xiong, Wei; Tan, Baosheng; Geng, Wei; Li, Jun; Liu, Hongchen

    2014-01-01

    Our previous studies demonstrated that glimepiride enhanced the proliferation and differentiation of osteoblasts and led to activation of the PI3K/Akt pathway. Recent genetic evidence shows that endothelial nitric oxide synthase (eNOS) plays an important role in bone homeostasis. In this study, we further elucidated the roles of eNOS, PI3K and Akt in bone formation by osteoblasts induced by glimepiride in a high glucose microenvironment. We demonstrated that high glucose (16.5 mM) inhibits the osteogenic differentiation potential and proliferation of rat osteoblasts. Glimepiride activated eNOS expression in rat osteoblasts cultured with two different concentrations of glucose. High glucose-induced osteogenic differentiation was significantly enhanced by glimepiride. Down-regulation of PI3K P85 levels by treatment with LY294002 (a PI3K inhibitor) led to suppression of P-eNOS and P-AKT expression levels, which in turn resulted in inhibition of RUNX2, OCN and ALP mRNA expression in osteoblasts induced by glimepiride at both glucose concentrations. ALP activity was partially inhibited by 10 µM LY294002. Taken together, our results demonstrate that glimepiride-induced osteogenic differentiation of osteoblasts occurs via eNOS activation and is dependent on the PI3K/Akt signaling pathway in a high glucose microenvironment. PMID:25391146

  14. Andrographolide promotes vincristine-induced SK-NEP-1 tumor cell death via PI3K-AKT-p53 signaling pathway

    PubMed Central

    Zhang, Mingsheng; Xue, Enda; Shao, Wei

    2016-01-01

    Background Nephroblastoma (Wilms’ tumor [WT]) is the most common malignant renal cancer in children. Although the outcome of WT has significantly improved as a result of the combination of surgery, chemotherapy, and radiotherapy; in some cases WT results in severe complications. Thus, novel strategies that would decrease treatment burden are required. The aim of the current study was to investigate the synergistic antitumor effect of andrographolide (AND) in combination with vincristine (VCR) on WT cells. Methods Cell Counting Kit-8 assay was used to investigate the synergistic antiproliferation effect of AND and/or VCR on SK-NEP-1 cells in vitro. Meanwhile, SK-NEP-1 xenografts were used to detect the antitumor effect in vivo. Apoptosis and autophagy were then detected by Annexin V, monodansylcadaverine staining. Finally, the underlying signaling transduction was determined with Western blotting. Results The combination of AND with VCR significantly suppressed SK-NEP-1 cell proliferation in vitro and inhibited xenograft tumor growth in vivo, compared with AND or VCR treatment alone. In addition, the synergistic antitumor effect of AND on the cells was due to an increased apoptosis, not autophagy. Moreover, PI3K-AKT-p53 signaling pathway was involved in the process of combination treatment, which was confirmed when a selective AKT activator was applied. Conclusion The combination of AND with VCR has a strong synergistic antitumor effect on WT via PI3K-AKT-p53 signaling pathway, thereby representing a potential treatment for WT in the near future. PMID:27729773

  15. The promotion of angiogenesis induced by three-dimensional porous beta-tricalcium phosphate scaffold with different interconnection sizes via activation of PI3K/Akt pathways.

    PubMed

    Xiao, Xin; Wang, Wei; Liu, Dong; Zhang, Haoqiang; Gao, Peng; Geng, Lei; Yuan, Yulin; Lu, Jianxi; Wang, Zhen

    2015-01-01

    The porous architectural characteristics of biomaterials play an important role in scaffold revascularization. However, no consensus exists regarding optimal interconnection sizes for vascularization and its scaffold bioperformance with different interconnection sizes. Therefore, a series of disk-type beta-tricalcium phosphates with the same pore sizes and variable interconnections were produced to evaluate how the interconnection size influenced biomaterial vascularization in vitro and in vivo. We incubated human umbilical vein endothelial cells on scaffolds with interconnections of various sizes. Results showed that scaffolds with a 150 μm interconnection size ameliorated endothelial cell function evidenced by promoting cell adhesion and migration, increasing cell proliferation and enhancing expression of platelet-endothelial cell adhesion molecules and vascular endothelial growth factor. In vivo study was performed on rabbit implanted with scaffolds into the bone defect on femoral condyles. Implantation with scaffolds with 150 μm interconnection size significantly improved neovascularization as shown by micro-CT as compared to scaffolds with 100 and 120 μm interconnection sizes. Moreover, the aforementioned positive effects were abolished by blocking PI3K/Akt/eNOS pathway with LY-294002. Our study explicitly demonstrates that the scaffold with 150 μm interconnection size improves neovascularization via the PI3K/Akt pathway and provides a target for biomaterial inner structure modification to attain improved clinical performance in implant vascularization.

  16. CXCL10/CXCR3 axis promotes the invasion of gastric cancer via PI3K/AKT pathway-dependent MMPs production.

    PubMed

    Zhou, Hongfeng; Wu, Jin; Wang, Tianjiao; Zhang, Xufeng; Liu, Dan

    2016-08-01

    CXCR3, a G-protein coupled chemokine receptor, has been found to be overexpressed in many tumors and act as an independent prognostic marker. However, it is still unclear whether CXCR3 is involved in gastric cancer progression. In this study, we found that CXCR3 was markedly expressed in gastric cancer cells and tissues. High CXCR3 expression correlated with advanced tumor stage, vascular invasion, lymph node metastasis and poor survival of gastric cancer patients. Activation of CXCR3 by one of its ligands CXCL10 promoted the invasion and migration of gastric cancer BGC-823 and MGC-803 cells, and increased the secretion and activities of MMP-2 and MMP-9. However, the effects of CXCL10 on gastric cancer cells were attenuated by CXCR3 siRNA transfection. Furthermore, overexpression of CXCR3 enhanced CXCL10-mediated cell invasion and migration of gastric cancer MKN28 cells. In addition, CXCR3 time-dependently induced activation of AKT. PI3K/AKT pathway was required for CXCR3-mediated gastric cancer cell invasion, migration and MMP-2/9 production. Together, our findings suggest that CXCL10/CXCR3 axis promotes gastric cancer cell invasion and migration by upregulating MMP-2 and MMP-9 production via PI3K/AKT pathway. Thus, CXCR3 could be a potential target for the gastric cancer treatment.

  17. FGF2 regulates proliferation, migration, and invasion of ECA109 cells through PI3K/Akt signalling pathway in vitro.

    PubMed

    Shi, Hui; Xu, Jingjing; Zhao, Rui; Wu, Huiqun; Gu, Luo; Chen, Yijiang

    2016-05-01

    Esophageal cancer is one of the most common malignant cancers that arise from esophagus tissues. Fibroblast growth factor 2 (FGF2) has been implicated in multiple biological functions and was considered as an oncogenic factor in tumorigenesis. However, the effects of FGF2 in esophageal carcinoma are yet to be fully elucidated. To better understand the function of FGF2 in esophageal cancer, we used the esophageal cancer cell line ECA109 as a cell model and downregulated FGF2 expression using RNAi; the results showed that insufficient expression of FGF2 inhibited cells proliferation, migration, and invasion of ECA109 cells. Meanwhile, the proliferation, migration, and invasion abilities were stimulated after treatment of exogenous FGF2. In addition, a PI3K/Akt signalling pathway inhibitor (LY294002) alleviated the tumorigenic effects of FGF2. These findings implied that the oncogenic effects of FGF2 was mediated, at least in part, through the PI3K/Akt signalling pathway and FGF2 may be a potential therapeutic target to constrain the tumorigenesis of esophageal cancer. PMID:26833879

  18. Methylglyoxal induces platelet hyperaggregation and reduces thrombus stability by activating PKC and inhibiting PI3K/Akt pathway.

    PubMed

    Hadas, Karin; Randriamboavonjy, Voahanginirina; Elgheznawy, Amro; Mann, Alexander; Fleming, Ingrid

    2013-01-01

    Diabetes is characterized by a dysregulation of glucose homeostasis and platelets from patients with diabetes are known to be hyper-reactive and contribute to the accelerated development of vascular diseases. Since many of the deleterious effects of glucose have been attributed to its metabolite methylgyloxal (MG) rather than to hyperglycemia itself, the aim of the present study was to characterize the effects of MG on platelet function. Washed human platelets were pre-incubated for 15 min with MG and platelet aggregation, adhesion on matrix-coated slides and signaling (Western blot) were assessed ex vivo. In vivo, the effect of MG on thrombus formation was determined using the FeCl3-induced carotid artery injury model. MG potentiated thrombin-induced platelet aggregation and dense granule release, but inhibited platelet spreading on fibronectin and collagen. In vivo, MG accelerated thrombus formation but decreased thrombus stability. At the molecular level, MG increased intracellular Ca(2+) and activated classical PKCs at the same time as inhibiting PI3K/Akt and the β3-integrin outside-in signaling. In conclusion, these findings indicate that the enhanced MG concentration measured in diabetic patients can directly contribute to the platelet dysfunction associated with diabetes characterized by hyperaggregability and reduced thrombus stability.

  19. Dryofragin inhibits the migration and invasion of human osteosarcoma U2OS cells by suppressing MMP-2/9 and elevating TIMP-1/2 through PI3K/AKT and p38 MAPK signaling pathways.

    PubMed

    Su, Yan; Wan, Daqian; Song, Wenqi

    2016-08-01

    Dryofragin, a phloroglucinol derivative extracted from Dryopteris fragrans (L.) Schott, was found to inhibit proliferation and induce apoptosis of tumor cells. However, the mechanism involved in the suppression of cancer cell metastasis by dryofragin remains unclear. Our study investigated the mechanisms for the antitumor properties of dryofragin on the migration and invasion of human osteosarcoma U2OS cells. Dryofragin suppressed the migration and invasive ability of U2OS cells, and it decreased the expression of MMP-2 and MMP-9 and elevated the expression of TIMP-1 and TIMP-2. Western blotting assays indicated that dryofragin was effective in suppressing the phosphorylation of phosphatidylinositide-3 kinase (PI3K), Akt, and p38 MAPK. These results suggest that dryofragin inhibited U2OS cell migration and invasion by reducing the expression of MMP-2 and MMP-9 and elevating the expression of TIMP-1 and TIMP-2 through the PI3K/AKT and p38 MAPK signaling pathways. Above all, we conclude that dryofragin represents an anti-invasive agent and may potentially be applicable in osteosarcoma therapy. PMID:27243922

  20. Osthole shows the potential to overcome P-glycoprotein‑mediated multidrug resistance in human myelogenous leukemia K562/ADM cells by inhibiting the PI3K/Akt signaling pathway.

    PubMed

    Wang, Hong; Jia, Xiu-Hong; Chen, Jie-Ru; Wang, Jian-Yong; Li, You-Jie

    2016-06-01

    P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) has been reported to play a pivotal role in tumor chemotherapy failure. Study after study has illustrated that the phosphoinositide 3-kinase (PI3K)/Akt signaling cascade is involved in the MDR phenotype and is correlated with P-gp expression in many human malignancies. In the present study, osthole, an O-methylated coumarin, exhibited potent reversal capability of MDR in myelogenous leukemia K562/ADM cells. Simultaneously, the uptake and efflux of Rhodamine-123 (Rh-123) and the accumulation of doxorubicin assays combined with flow cytometric analysis suggested that osthole could increase intracellular drug accumulation. Furthermore, osthole decreased the expression of multidrug resistance gene 1 (MDR1) at both the mRNA and protein levels. Further experiments elucidated that osthole could suppress P-gp expression by inhibiting the PI3K/Akt signaling pathway which might be the main mechanism accounting for the reversal potential of osthole in the MDR in K562/ADM cells. In conclusion, osthole combats MDR and could be a promising candidate for the development of novel MDR reversal modulators. PMID:27109742

  1. Lycopene inhibits PDGF-BB-induced retinal pigment epithelial cell migration by suppression of PI3K/Akt and MAPK pathways

    SciTech Connect

    Chan, Chi-Ming; Fang, Jia-You; Lin, Hsin-Huang; Yang, Chi-Yea; Hung, Chi-Feng

    2009-10-09

    Retinal pigment epithelial (RPE) cells play a dominant role in the development of proliferative vitreoretinopathy (PVR), which is the leading cause of failure in retinal reattachment surgery. Several studies have shown that platelet-derived growth factor (PDGF) exhibits chemotaxis and proliferation effects on RPE cells in PVR. In this study, the inhibitory effect of lycopene on PDGF-BB-induced ARPE19 cell migration is examined. In electric cell-substrate impedance sensing (ECIS) and Transwell migration assays, significant suppression of PDGF-BB-induced ARPE19 cell migration by lycopene is observed. Cell viability assays show no cytotoxicity of lycopene on RPE cells. Lycopene shows no effect on ARPE19 cell adhesion and is found to inhibit PDGF-BB-induced tyrosine phosphorylation and the underlying signaling pathways of PI3K, Akt, ERK and p38 activation. However, PDGF-BB and lycopene show no effects on JNK activation. Taken together, our results demonstrate that lycopene inhibits PDGF-BB-induced ARPE19 cell migration through inhibition of PI3K/Akt, ERK and p38 activation.

  2. Trisubstituted-Imidazoles Induce Apoptosis in Human Breast Cancer Cells by Targeting the Oncogenic PI3K/Akt/mTOR Signaling Pathway

    PubMed Central

    Mervin, Lewis; Mohan, Surender; Paricharak, Shardul; Baday, Sefer; Li, Feng; Shanmugam, Muthu K.; Chinnathambi, Arunachalam; Zayed, M. E.; Alharbi, Sulaiman Ali; Bender, Andreas; Sethi, Gautam; Basappa; Rangappa, Kanchugarakoppal S.

    2016-01-01

    Overactivation of PI3K/Akt/mTOR is linked with carcinogenesis and serves a potential molecular therapeutic target in treatment of various cancers. Herein, we report the synthesis of trisubstituted-imidazoles and identified 2-chloro-3-(4, 5-diphenyl-1H-imidazol-2-yl) pyridine (CIP) as lead cytotoxic agent. Naïve Base classifier model of in silico target prediction revealed that CIP targets RAC-beta serine/threonine-protein kinase which comprises the Akt. Furthermore, CIP downregulated the phosphorylation of Akt, PDK and mTOR proteins and decreased expression of cyclin D1, Bcl-2, survivin, VEGF, procaspase-3 and increased cleavage of PARP. In addition, CIP significantly downregulated the CXCL12 induced motility of breast cancer cells and molecular docking calculations revealed that all compounds bind to Akt2 kinase with high docking scores compared to the library of previously reported Akt2 inhibitors. In summary, we report the synthesis and biological evaluation of imidazoles that induce apoptosis in breast cancer cells by negatively regulating PI3K/Akt/mTOR signaling pathway. PMID:27097161

  3. Furano-1,2-Naphthoquinone Inhibits Src and PI3K/Akt Signaling Pathways in Ca9-22 Human Oral Squamous Carcinoma Cells.

    PubMed

    Lin, Kuei-Li; Chien, Ching-Ming; Tseng, Chih-Hua; Chen, Yeh-Long; Chang, Long-Sen; Lin, Shinne-Ren

    2014-05-01

    Furano-1,2-naphthoquinone (FNQ), a biologically active component ofAvicennia marina, has been demonstrated to display anticancer activity. FNQ exerted cytotoxicity with the G2/M cell cycle arrest and apoptosis in Ca9-22 cells. FNQ-induced G2/M arrest was correlated with a marked decrease in the expression levels of cyclin A and cyclin B, and their activating partner cyclin-dependent kinases (CDK) 1 and 2 with concomitant induction of p27. FNQ-induced apoptosis was accompanied by Bax and Bad upregulation, and the downregulation of Bcl-2, Bcl-XL, Mcl-1, and X-linked inhibitor of apoptosis (XIAP), resulting in cytochrome C release and sequential activation of caspase-9 and caspase-3. Mechanistic studies showed that FNQ suppressed Src phosphorylation, PI3K, and Akt activation in Ca9-22 cells. Moreover, the Src inhibitor PP2 reduced the phosphorylation of Src and activation of PI3K/Akt, which was comparable with FNQ treatment. The combined treatment of FNQ with PP2 enhanced the cell cycle arrest and apoptosis and also led to the downregulation of Bcl-XL, Mcl-1, XIAP, cyclin A, cyclin B, CDK1, and CDK2 and upregulation of p27, Bax, and Bad. These findings suggest that FNQ-mediated cytotoxicity of Ca9-22 cells is related with the G2/M cell cycle arrest and apoptosis via inactivation of Src and PI3K/Akt-mediated signaling pathways. PMID:22505597

  4. Extracellular matrix secreted by senescent fibroblasts induced by UVB promotes cell proliferation in HaCaT cells through PI3K/AKT and ERK signaling pathways.

    PubMed

    Kang, Jian; Chen, Wenqi; Xia, Jiping; Li, Yanhua; Yang, Bo; Chen, Bin; Sun, Weiling; Song, Xiuzu; Xiang, Wenzhong; Wang, Xiaoyong; Wang, Fei; Bi, Zhigang; Wan, Yinsheng

    2008-06-01

    Chronic exposure to solar ultraviolet radiation (UV) induces photoaging, and ultimately photocarcinogenesis. Senescent human skin fibroblasts (HSFs) in UVB stress-induced premature senescence (UVB-SIPS) share a similar extracellular matrix (ECM) phenotype with other types of senescent fibroblast. ECM from senescent fibroblasts induced by a variety of stresses has been shown to promote preneoplastic and neoplastic epithelial cell growth, a potential mechanism in carcinogenesis. We undertook this study to explore whether the extracellular matrices from UVB-induced senescent fibroblasts have any effect on the proliferation of HaCaT cells. The results showed that ECM secreted from HSFs in UVB-SIPS has 13.15 and 29.27% more stimulatory effect on proliferation than ECM secreted from presenescent HSFs and non-ECM, respectively. ECM from fibroblasts in UVB-SIPS activates FAK, ERK, and AKT in HaCaT cells. ERK and PI3K/AKT inhibitors inhibit ECM-induced ERK, AKT activation and cell proliferation. Cytochalasin D, a destructive agent of the cytoskeleton, inhibits ECM-induced FAK activation and cell proliferation in HaCaT cells. Collectively, we conclude that ECM secreted from HSFs in UVB-SIPS promotes cell proliferation via ERK and PI3K/AKT pathways and modulation of FAK and cytoskeletal proteins in HaCaT cells. Pharmacological manipulation of those signaling components may lead to the prevention and treatment of skin cancer induced by chronic solar exposure.

  5. Low-Molecular-Weight Fucoidan Induces Endothelial Cell Migration via the PI3K/AKT Pathway and Modulates the Transcription of Genes Involved in Angiogenesis

    PubMed Central

    Bouvard, Claire; Galy-Fauroux, Isabelle; Grelac, Françoise; Carpentier, Wassila; Lokajczyk, Anna; Gandrille, Sophie; Colliec-Jouault, Sylvia; Fischer, Anne-Marie; Helley, Dominique

    2015-01-01

    Low-molecular-weight fucoidan (LMWF) is a sulfated polysaccharide extracted from brown seaweed that presents antithrombotic and pro-angiogenic properties. However, its mechanism of action is not well-characterized. Here, we studied the effects of LMWF on cell signaling and whole genome expression in human umbilical vein endothelial cells and endothelial colony forming cells. We observed that LMWF and vascular endothelial growth factor had synergistic effects on cell signaling, and more interestingly that LMWF by itself, in the absence of other growth factors, was able to trigger the activation of the PI3K/AKT pathway, which plays a crucial role in angiogenesis and vasculogenesis. We also observed that the effects of LMWF on cell migration were PI3K/AKT-dependent and that LMWF modulated the expression of genes involved at different levels of the neovessel formation process, such as cell migration and cytoskeleton organization, cell mobilization and homing. This provides a better understanding of LMWF’s mechanism of action and confirms that it could be an interesting therapeutic approach for vascular repair. PMID:26694425

  6. Thrombin Promotes Matrix Metalloproteinase-13 Expression through the PKCδ/c-Src/EGFR/PI3K/Akt/AP-1 Signaling Pathway in Human Chondrocytes

    PubMed Central

    Huang, Chun-Yin; Lin, Hsiu-Jung; Chen, Hsin-Shui; Cheng, Shi-Yann; Hsu, Horng-Chaung; Tang, Chih-Hsin

    2013-01-01

    Thrombin is a key mediator of fibrin deposition, angiogenesis, and proinflammatory processes. Abnormalities in these processes are primary features of rheumatoid arthritis and osteoarthritis. Matrix metalloproteinase-13 (MMP-13) may contribute to the breakdown of articular cartilage during arthritis. However, the role of thrombin in MMP-13 production in chondrocytes is unknown. In this study, we investigated the intracellular signaling pathways involved in thrombin-induced MMP-13 expression in human chondrocytes. We found that stimulation with thrombin led to increased secretion of MMP-13 in cultured human chondrocytes. Further, this thrombin-induced MMP-13 production was reduced after transfection with siRNAs against protease activated receptors 1 and 3 (PAR1 and PAR3), but not with PAR4 siRNA. Treatment with specific inhibitors for PKCδ, c-Src, EGFR, PI3K, Akt, or AP-1 or with the corresponding siRNAs against these signaling proteins also abolished the thrombin-mediated increase in MMP-13 production in chondrocytes. Our results provide evidence that thrombin acts through the PAR1/PAR3 receptors and activates PKCδ and c-Src, resulting in EGFR transactivation and activation of PI3K, Akt, and finally AP-1 on the MMP-13 promoter, thereby contributing to cartilage destruction during arthritis. PMID:24385683

  7. Activation of transient receptor potential vanilloid 4 induces apoptosis in hippocampus through downregulating PI3K/Akt and upregulating p38 MAPK signaling pathways

    PubMed Central

    Jie, P; Hong, Z; Tian, Y; Li, Y; Lin, L; Zhou, L; Du, Y; Chen, L; Chen, L

    2015-01-01

    Transient receptor potential vanilloid 4 (TRPV4) is a calcium-permeable cation channel that is sensitive to cell swelling, arachidonic acid and its metabolites, epoxyeicosatrienoic acids, which are associated with cerebral ischemia. The activation of TRPV4 induces cytotoxicity in many types of cells, accompanied by an increase in the intracellular free calcium concentration. TRPV4 activation modulates the mitogen-activated protein kinase (MAPK) and phosphatidyl inositol 3 kinase (PI3K)/ protein kinase B (Akt) signaling pathways that regulate cell death and survival. Herein, we examined TRPV4-induced neuronal apoptosis by intracerebroventricular (ICV) injection of a TRPV4 agonist (GSK1016790A) and assessed its involvement in cerebral ischemic injury. ICV injection of GSK1016790A dose-dependently induced apoptosis in the mouse hippocampi (GSK-injected mice). The protein level of phosphorylated p38 MAPK (p-p38 MAPK) was markedly increased and that of phosphorylated c-Jun N-terminal protein kinase (p-JNK) was virtually unchanged. TRPV4 activation also decreased Bcl-2/Bax protein ratio and increased the cleaved caspase-3 protein level, and these effects were blocked by a PI3K agonist and a p38 MAPK antagonist, but were unaffected by a JNK antagonist. ICV injection of the TRPV4 antagonist HC-067047 reduced brain infarction after reperfusion for 48 h in mice with middle cerebral artery occlusion (MCAO). In addition, HC-067047 treatment attenuated the decrease in the phosphorylated Akt protein level and the increase in p-p38 MAPK protein level at 48 h after MCAO, while the increase in p-JNK protein level remained unchanged. Finally, the decreased Bcl-2/Bax protein ratio and the increased cleaved caspase-3 protein level at 48 h after MCAO were markedly attenuated by HC-067047. We conclude that activation of TRPV4 induces apoptosis by downregulating PI3K/Akt and upregulating p38 MAPK signaling pathways, which is involved in cerebral ischemic injury. PMID:26043075

  8. Irisin inhibits hepatic gluconeogenesis and increases glycogen synthesis via the PI3K/Akt pathway in type 2 diabetic mice and hepatocytes.

    PubMed

    Liu, Tong-Yan; Shi, Chang-Xiang; Gao, Run; Sun, Hai-Jian; Xiong, Xiao-Qing; Ding, Lei; Chen, Qi; Li, Yue-Hua; Wang, Jue-Jin; Kang, Yu-Ming; Zhu, Guo-Qing

    2015-11-01

    Increased glucose production and reduced hepatic glycogen storage contribute to metabolic abnormalities in diabetes. Irisin, a newly identified myokine, induces the browning of white adipose tissue, but its effects on gluconeogenesis and glycogenesis are unknown. In the present study, we investigated the effects and underlying mechanisms of irisin on gluconeogenesis and glycogenesis in hepatocytes with insulin resistance, and its therapeutic role in type 2 diabetic mice. Insulin resistance was induced by glucosamine (GlcN) or palmitate in human hepatocellular carcinoma (HepG2) cells and mouse primary hepatocytes. Type 2 diabetes was induced by streptozotocin/high-fat diet (STZ/HFD) in mice. In HepG2 cells, irisin ameliorated the GlcN-induced increases in glucose production, phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) expression, and glycogen synthase (GS) phosphorylation; it prevented GlcN-induced decreases in glycogen content and the phosphoinositide 3-kinase (PI3K) p110α subunit level, and the phosphorylation of Akt/protein kinase B, forkhead box transcription factor O1 (FOXO1) and glycogen synthase kinase-3 (GSK3). These effects of irisin were abolished by the inhibition of PI3K or Akt. The effects of irisin were confirmed in mouse primary hepatocytes with GlcN-induced insulin resistance and in human HepG2 cells with palmitate-induced insulin resistance. In diabetic mice, persistent subcutaneous perfusion of irisin improved the insulin sensitivity, reduced fasting blood glucose, increased GSK3 and Akt phosphorylation, glycogen content and irisin level, and suppressed GS phosphorylation and PEPCK and G6Pase expression in the liver. Irisin improves glucose homoeostasis by reducing gluconeogenesis via PI3K/Akt/FOXO1-mediated PEPCK and G6Pase down-regulation and increasing glycogenesis via PI3K/Akt/GSK3-mediated GS activation. Irisin may be regarded as a novel therapeutic strategy for insulin resistance and type 2 diabetes.

  9. Camptothecin inhibits platelet-derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells through inhibition of PI3K/Akt signaling pathway

    SciTech Connect

    Park, Eun-Seok; Kang, Shin-il; Yoo, Kyu-dong; Lee, Mi-Yea; Yoo, Hwan-Soo; Hong, Jin-Tae; Shin, Hwa-Sup; Kim, Bokyung; Yun, Yeo-Pyo

    2013-04-15

    The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is a major cause of vascular disorders such as atherosclerosis and restenosis after angioplasty. In this study, we investigated not only the inhibitory effects of camptothecin (CPT) on PDGF-BB-induced VSMC proliferation, but also its molecular mechanism of this inhibition. CPT significantly inhibited proliferation with IC50 value of 0.58 μM and the DNA synthesis of PDGF-BB-stimulated VSMCs in a dose-dependent manner (0.5–2 μM ) without any cytotoxicity. CPT induced the cell cycle arrest at G0/G1 phase. Also, CPT decreased the expressions of G0/G1-specific regulatory proteins including cyclin-dependent kinase (CDK)2, cyclin D1 and PCNA in PDGF-BB-stimulated VSMCs. Pre-incubation of VSMCs with CPT significantly inhibited PDGF-BB-induced Akt activation, whereas CPT did not affect PDGF-receptor beta phosphorylation, extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and phospholipase C (PLC)-γ1 phosphorylation in PDGF-BB signaling pathway. Our data showed that CPT pre-treatment inhibited VSMC proliferation, and that the inhibitory effect of CPT was enhanced by LY294002, a PI3K inhibitor, on PDGF-BB-induced VSMC proliferation. In addition, inhibiting the PI3K/Akt pathway by LY294002 significantly enhanced the suppression of PCNA expression and Akt activation by CPT. These results suggest that the anti-proliferative activity of CPT is mediated in part by downregulating the PI3K/Akt signaling pathway. - Highlights: ► CPT inhibits proliferation of PDGF-BB-induced VSMC without cytotoxicity. ► CPT arrests the cell cycle in G0/G1 phase by downregulation of cyclin D1 and CDK2. ► CPT significantly attenuates Akt phosphorylation in PDGF-BB signaling pathway. ► LY294002 enhanced the inhibitory effect of CPT on VSMC proliferation. ► Thus, CPT is mediated by downregulating the PI3K/Akt signaling pathway.

  10. Anti-Fibrotic Actions of Interleukin-10 against Hypertrophic Scarring by Activation of PI3K/AKT and STAT3 Signaling Pathways in Scar-Forming Fibroblasts

    PubMed Central

    Cai, Weixia; Bai, Xiaozhi; Fang, Xiaobing; Hu, Xiaolong; Wang, Yaojun; Wang, Hongtao; Zheng, Zhao; Su, Linlin; Hu, Dahai; Zhu, Xiongxiang

    2014-01-01

    fibrosis by activating AKT and STAT3 phosphorylation downstream of the IL-10 receptor, and by facilitating crosstalk between the PI3K/AKT and STAT3 signal transduction pathways. PMID:24878845

  11. Puquitinib mesylate (XC-302) induces autophagy via inhibiting the PI3K/AKT/mTOR signaling pathway in nasopharyngeal cancer cells.

    PubMed

    Wang, Ke-Feng; Yang, Hang; Jiang, Wen-Qi; Li, Su; Cai, Yu-Chen

    2015-12-01

    provides the evidence that XC-302 can induce autophagy in CNE-2, which promotes the program of cell death and inhibits the PI3K/AKT/mTOR signaling pathway. Furthermore, XC-302 also promoted apoptosis in CNE-2 cells, which could be reduced when autophagy was suppressed, meaning that autophagy may interact with apoptosis to induce cell death.

  12. Calycosin-7-O-β-d-glucoside attenuates ischemia-reperfusion injury in vivo via activation of the PI3K/Akt pathway

    PubMed Central

    REN, MIN; WANG, XUDONG; DU, GUOQING; TIAN, JIAWEI; LIU, YUJIE

    2016-01-01

    The aim of the present study was to investigate the effects and mechanisms of calycosin-7-O-β-d-glucoside (CG) on ischemia-reperfusion (I/R) injury in vivo. Hemodynamic parameters, including ejection fraction (EF), fractional shortening (FS), left ventricular end-systolic pressure (LVESP) and left ventricular end-diastolic pressure (LVEDP) were monitored using an ultrasound system, and infarct size was measured using Evans blue/tetrazolium chloride double staining. The activities of serum creatine kinase (CK), lactate dehydrogenase (LDH) and superoxide dismutase (SOD), and the levels of malondialdehyde (MDA) were determined to assess the degree of myocardial injury and oxidative stress-induced damage. The protein expression levels of cleaved-caspase-3, cleaved-caspase-9, phosphorylated (p)-phosphatidylinositol 3-kinase (PI3K) p85, PI3K p85, p-Akt and Akt were determined using western blotting. The results demonstrated that pretreatment with high dose (H)-CG markedly improved cardiac function, as evidenced by upregulated EF, FS and LVESP, and downregulated LVEDP. In addition, administration of CG resulted in significant decreases in infarct size in the I/R+low dose-CG and I/R+H-CG groups, compared with the I/R group. The activities of CK and LDH, and the levels of MDA in the I/R+H-CG group were reduced, compared with those in the I/R group, whereas SOD activity was elevated. Treatment with CG inhibited the cleavage and activity of caspase-3 and caspase-9, and enhanced the phosphorylation of PI3K p85 and Akt. Notably, administration of the PI3K inhibitor, LY294002, markedly lowered the levels of p-PI3K p85/p-Akt, and eradicated the inhibitory effects of H-CG on infarct size, myocardial injury and oxidative stress-induced damage. Taken together, the results suggested that CG may alleviate I/R injury by activating the PI3K/Akt signaling pathway. PMID:26648122

  13. MiR-34a targets GAS1 to promote cell proliferation and inhibit apoptosis in papillary thyroid carcinoma via PI3K/Akt/Bad pathway

    SciTech Connect

    Ma, Yanfei; Qin, Huadong; Cui, Yunfu

    2013-11-29

    Highlights: •MiR-34a is up- and GAS1 is down-regulated in papillary thyroid carcinoma. •GAS1 is a direct target for miR-34a. •MiR-34a promotes PTC cells proliferation and inhibits apoptosis through PI3K/Akt/Bad pathway. -- Abstract: MicroRNAs (miRNAs) are fundamental regulators of cell proliferation, differentiation, and apoptosis, and are implicated in tumorigenesis of many cancers. MiR-34a is best known as a tumor suppressor through repression of growth factors and oncogenes. Growth arrest specific1 (GAS1) protein is a tumor suppressor that inhibits cancer cell proliferation and induces apoptosis through inhibition of RET receptor tyrosine kinase. Both miR-34a and GAS1 are frequently down-regulated in various tumors. However, it has been reported that while GAS1 is down-regulated in papillary thyroid carcinoma (PTC), miR-34a is up-regulated in this specific type of cancer, although their potential roles in PTC tumorigenesis have not been examined to date. A computational search revealed that miR-34a putatively binds to the 3′-UTR of GAS1 gene. In the present study, we confirmed previous findings that miR-34a is up-regulated and GAS1 down-regulated in PTC tissues. Further studies indicated that GAS1 is directly targeted by miR-34a. Overexpression of miR-34a promoted PTC cell proliferation and colony formation and inhibited apoptosis, whereas knockdown of miR-34a showed the opposite effects. Silencing of GAS1 had similar growth-promoting effects as overexpression of miR-34a. Furthermore, miR-34a overexpression led to activation of PI3K/Akt/Bad signaling pathway in PTC cells, and depletion of Akt reversed the pro-growth, anti-apoptotic effects of miR-34a. Taken together, our results demonstrate that miR-34a regulates GAS1 expression to promote proliferation and suppress apoptosis in PTC cells via PI3K/Akt/Bad pathway. MiR-34a functions as an oncogene in PTC.

  14. O-GlcNAcylation enhances the invasion of thyroid anaplastic cancer cells partially by PI3K/Akt1 pathway

    PubMed Central

    Zhang, Peng; Wang, Chunli; Ma, Tao; You, Shengyi

    2015-01-01

    Background The PI3K family participates in multiple signaling pathways to regulate cellular functions. PI3K/Akt signaling pathway plays an important role in tumorigenesis and development. O-GlcNAcylation, a posttranslational modification, is thought to modulate a wide range of biological processes, such as transcription, cell growth, signal transduction, and cell motility. O-GlcNAcylation is catalyzed by the nucleocytoplasmic enzymes, OGT and OGA, which adds or removes O-GlcNAc moieties, respectively. Abnormal O-GlcNAcylation has been implicated in a variety of human diseases. However, the role of O-GlcNAcylation in tumorigenesis and progression of cancer is still under-investigated. Understanding the O-GlcNAc-associated molecular mechanism might be significant for diagnosis and therapy of cancer. Methods Human thyroid anaplastic cancer 8305C cells were used to evaluate the role of O-GlcNAcylation in tumorigenesis and progression of cancer. The global O-GlcNAc level of intracellular proteins was up-regulated by OGA inhibitor Thiamet-G treatment or OGT over-expression. Cell proliferation was assessed by MTT assay. Invasion in vitro was determined by Transwell assay, and phosphorylation of Akt1 at Ser473 was assessed by Western blot for activity of Akt1. PI3K-specific inhibitor LY294002 and RNA interference of Akt1 were used to investigate the impact of PI3K/Akt signaling on the regulation of O-GlcNAcylation during tumor progression. Results Cell models with remarkably up-regulated O-GlcNAcylation were constructed, and then cell proliferation and invasion were determined. The results indicated that the proliferation was not affected by OGA inhibition or OGT overexpression, while the invasion of 8305C cells with OGA inhibition or OGT overexpression was obviously increased. Akt1 activity was stimulated by elevated O-GlcNAcylation by mediating phosphorylation at Ser473. The enhanced invasion of thyroid cancer cells by Thiamet-G treatment or OGT overexpression was

  15. [PI3K-AKT-mTOR pathway: Description, therapeutic development, resistance, predictive/prognostic biomarkers and therapeutic applications for cancer].

    PubMed

    Brotelle, Thibault; Bay, Jacques-Olivier

    2016-01-01

    Among many cancer cells signaling pathways, PI3K-AKT-mTOR plays a major role in growth, proliferation and cellular survival. This is a complex pathway activated either by an extracellular way (receptors with tyrosine kinase activity) or by an intracellular way with transformed or overexpressed proteins involved in the signal transduction. To date, there are many applications of mTOR inhibitors in oncology with an expanding development rapidly. However, resistances appear to mTOR inhibitors which lead to 2nd generation mTOR inhibitors development. A better knowledge of predictive and prognostic biomarkers will allow to specify the group of patients who may benefit from these treatments and help to the choice. PMID:26582734

  16. A Genome-Wide RNAi Screen Identifies FOXO4 as a Metastasis-Suppressor through Counteracting PI3K/AKT Signal Pathway in Prostate Cancer

    PubMed Central

    Su, Bing; Gao, Lingqiu; Baranowski, Catherine; Gillard, Bryan; Wang, Jianmin; Ransom, Ryan; Ko, Hyun-Kyung; Gelman, Irwin H.

    2014-01-01

    Activation of the PI3K/AKT signal pathway is a known driving force for the progression to castration-recurrent prostate cancer (CR-CaP), which constitutes the major lethal phenotype of CaP. Here, we identify using a genomic shRNA screen the PI3K/AKT-inactivating downstream target, FOXO4, as a potential CaP metastasis suppressor. FOXO4 protein levels inversely correlate with the invasive potential of a panel of human CaP cell lines, with decreased mRNA levels correlating with increased incidence of clinical metastasis. Knockdown (KD) of FOXO4 in human LNCaP cells causes increased invasion in vitro and lymph node (LN) metastasis in vivo without affecting indices of proliferation or apoptosis. Increased Matrigel invasiveness was found by KD of FOXO1 but not FOXO3. Comparison of differentially expressed genes affected by FOXO4-KD in LNCaP cells in culture, in primary tumors and in LN metastases identified a panel of upregulated genes, including PIP, CAMK2N1, PLA2G16 and PGC, which, if knocked down by siRNA, could decrease the increased invasiveness associated with FOXO4 deficiency. Although only some of these genes encode FOXO promoter binding sites, they are all RUNX2-inducible, and RUNX2 binding to the PIP promoter is increased in FOXO4-KD cells. Indeed, the forced expression of FOXO4 reversed the increased invasiveness of LNCaP/shFOXO4 cells; the forced expression of FOXO4 did not alter RUNX2 protein levels, yet it decreased RUNX2 binding to the PIP promoter, resulting in PIP downregulation. Finally, there was a correlation between FOXO4, but not FOXO1 or FOXO3, downregulation and decreased metastasis-free survival in human CaP patients. Our data strongly suggest that increased PI3K/AKT-mediated metastatic invasiveness in CaP is associated with FOXO4 loss, and that mechanisms to induce FOXO4 re-expression might suppress CaP metastatic aggressiveness. PMID:24983969

  17. Niacin activates the PI3K/Akt cascade via PKC- and EGFR-transactivation-dependent pathways through hydroxyl-carboxylic acid receptor 2.

    PubMed

    Sun, Huawang; Li, Guo; Zhang, Wenjuan; Zhou, Qi; Yu, Yena; Shi, Ying; Offermanns, Stefan; Lu, Jianxin; Zhou, Naiming

    2014-01-01

    Niacin has been demonstrated to activate a PI3K/Akt signaling cascade to prevent brain damage after stroke and UV-induced skin damage; however, the underlying molecular mechanisms for HCA2-induced Akt activation remain to be elucidated. Using CHO-K1 cells stably expressing HCA2 and A431 cells, a human epidermoid cell line with high levels of endogenous expression of functional HCA2 receptors, we first demonstrated that niacin induced a robust Akt phosphorylation at both Thr308 and Ser473 in a time-dependent fashion, with a maximal activation at 5 min and a subsequent reduction to baseline by 30 min through HCA2, and that the activation was significantly blocked by pertussis toxin. The HCA2-mediated activation of Akt was also significantly inhibited by the PKC inhibitors GF109203x and Go6983 in both cell lines, by the PDGFR-selective inhibitor tyrphostin A9 in CHO-HCA2 cells and by the MMP inhibitor GM6001 and EGFR-specific inhibitor AG1478 in A431 cells. These results suggest that the PKC pathway and PDGFR/EGFR transactivation pathway play important roles in HCA2-mediated Akt activation. Further investigation indicated that PI3K and the Gβγ subunit were likely to play an essential role in HCA2-induced Akt activation. Moreover, Immunobloting analyses using an antibody that recognizes p70S6K1 phosphorylated at Thr389 showed that niacin evoked p70S6K1 activation via the PI3K/Akt pathway. The results of our study provide new insight into the signaling pathways involved in HCA2 activation.

  18. Involvement of the PI3K/Akt/GSK3β pathway in photodynamic injury of neurons and glial cells

    NASA Astrophysics Data System (ADS)

    Komandirov, M. A.; Knyazeva, E. A.; Fedorenko, Y. P.; Rudkovskii, M. V.; Stetsurin, D. A.; Uzdensky, A. B.

    2011-03-01

    Photodynamic treatment causes intense oxidative stress and kills cells. It is currently used in neurooncology. However, along with tumor it damages surrounding healthy neuronal and glial cells. In order to study the possible role of the phosphatidylinositol 3-kinase/protein kinase Akt/glycogen synthase kinase-3β signaling pathway in photodynamic damage to normal neurons and glia, we used isolated crayfish stretch receptor that consists only of a single neuron surrounded by glial cells. It was photosensitized with alumophthalocyanine Photosens (100 nM). The laser diode (670nm, 0.4W/cm2) was used as a light source. Application of specific inhibitors of the enzymes involved in this pathway showed that phosphatidylinositol 3-kinase did not participate in photoinduced death of neurons and glia. Protein kinase Akt was involved in photoinduced necrosis but not in apoptosis of neurons and glia. Glycogen synthase kinase-3β participated in photoinduced apoptosis of glial cells and in necrosis of neurons. Therefore, the phosphatidylinositol 3-kinase/protein kinase Akt/glycogen synthase kinase-3β pathway was not involved as a whole in photodynamic injury of crayfish neurons and glial cells but its components, protein kinase Akt and glycogen synthase kinase-3β, independently and cell-specifically regulated photoinduced death of neurons and glial cells. These data showed that in this system necrosis was not non-regulated and catastrophic mode of cell death. It was controlled by some signaling proteins. The obtained results may be used for search of pharmacological agents that selectively modulate injury of normal neurons and glial cells during photodynamic therapy of brain tumors.

  19. Involvement of the PI3K/Akt/GSK3β pathway in photodynamic injury of neurons and glial cells

    NASA Astrophysics Data System (ADS)

    Komandirov, M. A.; Knyazeva, E. A.; Fedorenko, Y. P.; Rudkovskii, M. V.; Stetsurin, D. A.; Uzdensky, A. B.

    2010-10-01

    Photodynamic treatment causes intense oxidative stress and kills cells. It is currently used in neurooncology. However, along with tumor it damages surrounding healthy neuronal and glial cells. In order to study the possible role of the phosphatidylinositol 3-kinase/protein kinase Akt/glycogen synthase kinase-3β signaling pathway in photodynamic damage to normal neurons and glia, we used isolated crayfish stretch receptor that consists only of a single neuron surrounded by glial cells. It was photosensitized with alumophthalocyanine Photosens (100 nM). The laser diode (670nm, 0.4W/cm2) was used as a light source. Application of specific inhibitors of the enzymes involved in this pathway showed that phosphatidylinositol 3-kinase did not participate in photoinduced death of neurons and glia. Protein kinase Akt was involved in photoinduced necrosis but not in apoptosis of neurons and glia. Glycogen synthase kinase-3β participated in photoinduced apoptosis of glial cells and in necrosis of neurons. Therefore, the phosphatidylinositol 3-kinase/protein kinase Akt/glycogen synthase kinase-3β pathway was not involved as a whole in photodynamic injury of crayfish neurons and glial cells but its components, protein kinase Akt and glycogen synthase kinase-3β, independently and cell-specifically regulated photoinduced death of neurons and glial cells. These data showed that in this system necrosis was not non-regulated and catastrophic mode of cell death. It was controlled by some signaling proteins. The obtained results may be used for search of pharmacological agents that selectively modulate injury of normal neurons and glial cells during photodynamic therapy of brain tumors.

  20. Expression of human telomerase reverse transcriptase mediates the senescence of mesenchymal stem cells through the PI3K/AKT signaling pathway.

    PubMed

    Zhao, Qiang; Wang, Xue-Yao; Yu, Xiao-Xia; Zhai, Ying-Xian; He, Xu; Wu, Shan; Shi, Ying-Ai

    2015-09-01

    Multipotent mesenchymal stem cells (MSCs) are widely used as seed cells in studies of tissue engineering and regenerative medicine; however, their clinical application is limited due to replicative senescence. It has been demonstrated that telomerase expression extends the lifespan and maintains the bone-forming ability of MSCs; however, the detailed role and the underlying molecular mechanisms in MSCs remain largely unknown. In the present study, we found that senescence was associated with human telomerase reverse transcriptase (hTERT) expression, and telomere length and telomerase activity. We established a short interfering RNA (siRNA) targeting hTERT and a gene expression vector carrying hTERT and transfected these into the MSCs to investigate the detailed role and the underlying molecular mechanisms of action of hTERT in MSCs. We found that the downregulation of hTERT by siRNA markedly decreased telomere length and telomerase activity in the MSCs, whereas the overexpression of hTERT increased telomere length and telomerase activity in the MSCs. The downregulation of hTERT inhibited cell proliferation and promoted the senescence and apoptosis of MSCs, whereas the upregulation of hTERT increased cell proliferation and decreased the senescence and apoptosis of MSCs. Of note, we also found that the activation of the PI3K/AKT signaling pathway was mediated by hTERT and that blocking this pathway using LY294002 inhibited hTERT expression, induced senescence and decreased the proliferation of MSCs. These findings reveal a previously unknown regulatory mechanism of hTERT, indicating that hTERT mediates the senescence of MSCs through the PI3K/AKT signaling pathway. PMID:26178664

  1. 6″-Debromohamacanthin A, a Bis (Indole) Alkaloid, Inhibits Angiogenesis by Targeting the VEGFR2-Mediated PI3K/AKT/mTOR Signaling Pathways

    PubMed Central

    Kim, Gi Dae; Cheong, Oug Jae; Bae, Song Yi; Shin, Jongheon; Lee, Sang Kook

    2013-01-01

    Hamacanthins, bis (indole) alkaloids, are found in a few marine sponges, including Spongosorites sp. Hamacanthins have been shown to possess cytotoxic, antibacterial and antifungal activities. However, the precise mechanism for the biological activities of hamacanthins has not yet been elucidated. In the present study, the anti-angiogenic effects of 6″-debromohamacanthin A (DBHA), an active component of isolated hamacanthins, were evaluated in cultured human umbilical vascular endothelial cells (HUVEC) and endothelial-like cells differentiated from mouse embryonic stem (mES) cells. DBHA significantly inhibited vascular endothelial growth factor (VEGF)-induced cell proliferation, migration and tube formation in the HUVEC. DBHA also suppressed the capillary-like structure formation and the expression of platelet endothelial cell adhesion molecule (PECAM), an endothelial biomarker, in mES cell-derived endothelial-like cells. To further understand the precise molecular mechanism of action, VEGF-mediated signaling pathways were analyzed in HUVEC cells and mES cell-derived endothelial-like cells. DBHA suppressed the VEGF-induced expression of MAPKs (p38, ERK and SAPK/JNK) and the PI3K/AKT/mTOR signaling pathway. In addition, DBHA inhibited microvessel sprouting in mES/EB-derived embryoid bodies. In an ex vivo model, DBHA also suppressed the microvessel sprouting of mouse aortic rings. The findings suggest for the first time that DBHA inhibits angiogenesis by targeting the vascular endothelial growth factor receptor 2 (VEGFR2)-mediated PI3K/AKT/mTOR signaling pathway in endothelial cells. PMID:23549281

  2. Carvacrol Alleviates Prostate Cancer Cell Proliferation, Migration, and Invasion through Regulation of PI3K/Akt and MAPK Signaling Pathways

    PubMed Central

    Luo, Yun; Wu, Jie-Ying; Lu, Min-Hua; Shi, Zhi

    2016-01-01

    TRPM7 is a potential therapeutic target for treatment of prostate cancer. In this study, we investigated the effects of nonselective TRPM7 inhibitor carvacrol on cell proliferation, migration, and invasion of prostate cancer PC-3 and DU145 cells. Our results showed that carvacrol blocked TRPM7-like currents in PC-3 and DU145 cells and reduced their proliferation, migration, and invasion. Moreover, carvacrol treatment significantly decreased MMP-2, p-Akt, and p-ERK1/2 protein expression and inhibited F-actin reorganization. Furthermore, consistently, TRPM7 knockdown reduced prostate cancer cell proliferation, migration, and invasion as well. Our study suggests that carvacrol may have therapeutic potential for the treatment of prostate cancer through its inhibition of TRPM7 channels and suppression of PI3K/Akt and MAPK signaling pathways. PMID:27803760

  3. Anti-diabetic effect of citrus pectin in diabetic rats and potential mechanism via PI3K/Akt signaling pathway.

    PubMed

    Liu, Yanlong; Dong, Man; Yang, Ziyu; Pan, Siyi

    2016-08-01

    This study was performed to investigate the anti-diabetic effect of citrus pectin in type 2 diabetic rats and its potential mechanism of action. The results showed that fasting blood glucose levels were significantly decreased after 4 weeks of citrus pectin administration. Citrus pectin improved glucose tolerance, hepatic glycogen content and blood lipid levels (TG, TC, LDL-c and HDL-c) in diabetic rats. Citrus pectin also significantly reduced insulin resistance, which played an important role in the resulting anti-diabetic effect. Moreover, after the pectin treatment, phosphorylated Akt expression was upregulated and GSK3β expression was downregulated, indicating that the potential anti-diabetic mechanism of citrus pectin might occur through regulation of the PI3K/Akt signaling pathway. Together, these results suggested that citrus pectin could ameliorate type 2 diabetes and potentially be used as an adjuvant treatment.

  4. C-reactive protein inhibits high-molecular-weight adiponectin expression in 3T3-L1 adipocytes via PI3K/Akt pathway.

    PubMed

    Liu, Yuanxin; Liu, Cuiping; Jiang, Chao; Wang, Su; Yang, Qichao; Jiang, Dan; Yuan, Guoyue

    2016-03-25

    Adiponectin, an adipose-specific protein hormone, is secreted from white adipose tissue and involved in glucose and lipid metabolism. It is assembled into low-molecular-weight trimer (LMW), middle-molecular-weight hexameric (MMW) and high-molecular-weight (HMW), among which HMW exhibits higher activity. In this study, we proved that C-reactive protein (CRP), an inflammatory marker, inhibited adiponectin expression, especially HMW in time-and dose-dependent manners. Furthermore, CRP decreased the HMW/total adiponectin ration and reduced adiponectin assembly by increasing ERp44, and decreasing Ero1-α and DsbA-L. CRP activated pAkt, the downstream of PI3K. Inhibition of PI3K or pAkt abolished the effect of CRP. Our study suggested that CRP decreased adiponectin expression and multimerization, while CRP-induced decline in adiponectin might be mediated through the PI3K/Akt pathway.

  5. Spironolactone promotes autophagy via inhibiting PI3K/AKT/mTOR signalling pathway and reduce adhesive capacity damage in podocytes under mechanical stress

    PubMed Central

    Li, Dong; Lu, Zhenyu; Xu, Zhongwei; Ji, Junya; Zheng, Zhenfeng; Lin, Shan; Yan, Tiekun

    2016-01-01

    Mechanical stress which would cause deleterious adhesive effects on podocytes is considered a major contributor to the early progress of diabetic nephropathy (DN). Our previous study has shown that spironolactone could ameliorate podocytic adhesive capacity in diabetic rats. Autophagy has been reported to have a protective role against renal injury. The present study investigated the underlying mechanisms by which spironolactone reduced adhesive capacity damage in podocytes under mechanical stress, focusing on the involvement of autophagy. Human conditional immortalized podocytes exposed to mechanical stress were treated with spironolactone, LY294002 or rapamycin for 48 h. The accumulation of LC3 puncta was detected by immunofluorescence staining. Podocyte expression of mineralocorticoid receptor (MR), integrin β1, LC3, Atg5, p85-PI3K, p-Akt, p-mTOR were detected by Western blotting. Podocyte adhesion to collagen type IV was also performed with spectrophotometry. Immunofluorescence staining showed that the normal level of autophagy was reduced in podocytes under mechanical stress. Decreased integrin β1, LC3, Atg5 and abnormal activation of the PI3K/Akt/mTOR pathway were also detected in podocytes under mechanical stress. Spironolactone up-regulated integrin β1, LC3, Atg5 expression, down-regulated p85-PI3K, p-Akt, p-mTOR expression and reduced podocytic adhesive capacity damage. Our data demonstrated that spironolactone inhibited mechanical-stress-induced podocytic adhesive capacity damage through blocking PI3K/Akt/mTOR pathway and restoring autophagy activity. PMID:27129295

  6. Insulin Protects Hepatic Lipotoxicity by Regulating ER Stress through the PI3K/Akt/p53 Involved Pathway Independently of Autophagy Inhibition

    PubMed Central

    Ning, Hua; Sun, Zongxiang; Liu, Yunyun; Liu, Lei; Hao, Liuyi; Ye, Yaxin; Feng, Rennan; Li, Jie; Li, Ying; Chu, Xia; Li, Songtao; Sun, Changhao

    2016-01-01

    The detrimental role of hepatic lipotoxicity has been well-implicated in the pathogenesis of NAFLD. Previously, we reported that inhibiting autophagy aggravated saturated fatty acid (SFA)-induced hepatotoxicity. Insulin, a physiological inhibitor of autophagy, is commonly increased within NAFLD mainly caused by insulin resistance. We therefore hypothesized that insulin augments the sensitivity of hepatocyte to SFA-induced lipotoxicity. The present study was conducted via employing human and mouse hepatocytes, which were exposed to SFAs, insulin, or their combination. Unexpectedly, our results indicated that insulin protected hepatocytes against SFA-induced lipotoxicity, based on the LDH, MTT, and nuclear morphological measurements, and the detection from cleaved-Parp-1 and -caspase-3 expressions. We subsequently clarified that insulin led to a rapid and short-period inhibition of autophagy, which was gradually recovered after 1 h incubation in hepatocytes, and such extent of inhibition was insufficient to aggravate SFA-induced lipotoxicity. The mechanistic study revealed that insulin-induced alleviation of ER stress contributed to its hepatoprotective role. Pre-treating hepatocytes with insulin significantly stimulated phosphorylated-Akt and reversed SFA-induced up-regulation of p53. Chemical inhibition of p53 by pifithrin-α robustly prevented palmitate-induced cell death. The PI3K/Akt pathway blockade by its special antagonist abolished the protective role of insulin against SFA-induced lipotoxicity and p53 up-regulation. Furthermore, we observed that insulin promoted intracellular TG deposits in hepatocytes in the present of palmitate. However, blocking TG accumulation via genetically silencing DGAT-2 did not prevent insulin-protected lipotoxicity. Our study demonstrated that insulin strongly protected against SFA-induced lipotoxicity in hepatocytes mechanistically through alleviating ER stress via a PI3K/Akt/p53 involved pathway but independently from autophagy

  7. PRL-3 promotes the peritoneal metastasis of gastric cancer through the PI3K/Akt signaling pathway by regulating PTEN.

    PubMed

    Xiong, Jianbo; Li, Zhengrong; Zhang, Yang; Li, Daojiang; Zhang, Guoyang; Luo, Xianshi; Jie, Zhigang; Liu, Yi; Cao, Yi; Le, Zhibiao; Tan, Shengxing; Zou, Wenyu; Gong, Peitao; Qiu, Lingyu; Li, Yuanyuan; Wang, Huan; Chen, Heping

    2016-10-01

    Peritoneal metastasis is the most frequent cause of death in patients with advanced gastric carcinoma (GC). The phosphatase of regenerating liver-3 (PRL-3) is recognized as an oncogene and plays an important role in GC peritoneal metastasis. However, the mechanism of how PRL-3 regulates GC invasion and metastasis is unknown. In the present study, we found that PRL-3 presented with high expression in GC with peritoneal metastasis, but phosphatase and tensin homologue (PTEN) was weakly expressed. The p-PTEN/PTEN ratio was also higher in GC with peritoneal metastasis than that in the normal gastric tissues. We also found the same phenomenon when comparing the gastric mucosa cell line with the GC cell lines. After constructing a wild-type and a mutant-type plasmid without enzyme activity and transfecting them into GC SGC7901 cells, we showed that only PRL-3 had enzyme activity to downregulate PTEN and cause PTEN phosphorylation. The results also showed that PRL-3 increased the expression levels of MMP-2/MMP-9 and promoted the migration and invasion of the SGC7901 cells. Knockdown of PRL-3 decreased the expression levels of MMP-2/MMP-9 significantly, which further inhibited the migration and invasion of the GC cells. PRL-3 also increased the expression ratio of p-Akt/Akt, which indicated that PRL-3 may mediate the PI3K/Akt pathway to promote GC metastasis. When we transfected the PTEN siRNA plasmid into the PRL-3 stable low expression GC cells, the expression of p-Akt, MMP-2 and MMP-9 was reversed. In conclusion, our results provide a bridge between PRL-3 and PTEN; PRL-3 decreased the expression of PTEN as well as increased the level of PTEN phosphorylation and inactivated it, consequently activating the PI3K/Akt signaling pathway, and upregulating MMP-2/MMP-9 expression to promote GC cell peritoneal metastasis.

  8. PRL-3 promotes the peritoneal metastasis of gastric cancer through the PI3K/Akt signaling pathway by regulating PTEN

    PubMed Central

    Xiong, Jianbo; Li, Zhengrong; Zhang, Yang; Li, Daojiang; Zhang, Guoyang; Luo, Xianshi; Jie, Zhigang; Liu, Yi; Cao, Yi; Le, Zhibiao; Tan, Shengxing; Zou, Wenyu; Gong, Peitao; Qiu, Lingyu; Li, Yuanyuan; Wang, Huan; Chen, Heping

    2016-01-01

    Peritoneal metastasis is the most frequent cause of death in patients with advanced gastric carcinoma (GC). The phosphatase of regenerating liver-3 (PRL-3) is recognized as an oncogene and plays an important role in GC peritoneal metastasis. However, the mechanism of how PRL-3 regulates GC invasion and metastasis is unknown. In the present study, we found that PRL-3 presented with high expression in GC with peritoneal metastasis, but phosphatase and tensin homologue (PTEN) was weakly expressed. The p-PTEN/PTEN ratio was also higher in GC with peritoneal metastasis than that in the normal gastric tissues. We also found the same phenomenon when comparing the gastric mucosa cell line with the GC cell lines. After constructing a wild-type and a mutant-type plasmid without enzyme activity and transfecting them into GC SGC7901 cells, we showed that only PRL-3 had enzyme activity to downregulate PTEN and cause PTEN phosphorylation. The results also showed that PRL-3 increased the expression levels of MMP-2/MMP-9 and promoted the migration and invasion of the SGC7901 cells. Knockdown of PRL-3 decreased the expression levels of MMP-2/MMP-9 significantly, which further inhibited the migration and invasion of the GC cells. PRL-3 also increased the expression ratio of p-Akt/Akt, which indicated that PRL-3 may mediate the PI3K/Akt pathway to promote GC metastasis. When we transfected the PTEN siRNA plasmid into the PRL-3 stable low expression GC cells, the expression of p-Akt, MMP-2 and MMP-9 was reversed. In conclusion, our results provide a bridge between PRL-3 and PTEN; PRL-3 decreased the expression of PTEN as well as increased the level of PTEN phosphorylation and inactivated it, consequently activating the PI3K/Akt signaling pathway, and upregulating MMP-2/MMP-9 expression to promote GC cell peritoneal metastasis. PMID:27572739

  9. MicroRNA-107 inhibits tumor growth and metastasis by targeting the BDNF-mediated PI3K/AKT pathway in human non-small lung cancer

    PubMed Central

    Xia, Huan; Li, Yang; Lv, Xiaohong

    2016-01-01

    Abnormal expression of microRNA-107 (miR-107) was found in non-small cell lung cancer (NSCLC). However, little is known about its role and molecular mechanism in NSCLC progression and metastasis. Therefore, the aims of this study were to clarify the potential role of miR-107 and molecular mechanism in NSCLC progression and metastasis. Quantitative real-time polymerase chain reaction assay showed that miR-107 expression levels were significantly decreased in NSCLC tissue and cell lines. Low miR-107 levels in tumor tissue correlated with advanced TNM stage and lymph node metastasis. Function assays showed that overexpression of miR-107 suppressed cell proliferation, migration and invasion in A549 cells in vitro, and inhibited NSCLC tumor growth in vivo. Further mechanism assays suggested the brain-derived neurotrophic factor (BDNF) was identified as a target gene of miR-107 in NSCLC cells. In addition, BDNF expression was upregulated, and inversely correlated with miR-107 in NSCLC tissues. Enforced overexpression of BDNF effectively reversed the tumor suppressive functions of miR-107 on NSCLC proliferation, migration and invasion. miR-107 overexpression or downregulation of BDNF was able to inhibit activation of PI3K/AKT signaling pathway. Taken together, our findings present the first evidence that miR-107 could suppress NSCLC metastasis by targeting BDNF and indirectly regulating PI3K/AKT signaling pathway, which might lead to a potential therapeutic strategy focusing on miR-107 and BDNF for human NSCLC. PMID:27498977

  10. PI3K/AKT/mTOR and sonic hedgehog pathways cooperate together to inhibit human pancreatic cancer stem cell characteristics and tumor growth

    PubMed Central

    Sharma, Narinder; Nanta, Rajesh; Sharma, Jay; Gunewardena, Sumedha; Singh, Karan P.; Shankar, Sharmila; Srivastava, Rakesh K.

    2015-01-01

    Cancer stem cells (CSCs) play major roles in cancer initiation, progression, and metastasis. It is evident from growing reports that PI3K/Akt/mTOR and Sonic Hedgehog (Shh) signaling pathways are aberrantly reactivated in pancreatic CSCs. Here, we examined the efficacy of combining NVP-LDE-225 (PI3K/mTOR inhibitor) and NVP-BEZ-235 (Smoothened inhibitor) on pancreatic CSCs characteristics, microRNA regulatory network, and tumor growth. NVP-LDE-225 co-operated with NVP-BEZ-235 in inhibiting pancreatic CSC's characteristics and tumor growth in mice by acting at the level of Gli. Combination of NVP-LDE-225 and NVP-BEZ-235 inhibited self-renewal capacity of CSCs by suppressing the expression of pluripotency maintaining factors Nanog, Oct-4, Sox-2 and c-Myc, and transcription of Gli. NVP-LDE-225 co-operated with NVP-BEZ-235 to inhibit Lin28/Let7a/Kras axis in pancreatic CSCs. Furthermore, a superior interaction of these drugs was observed on spheroid formation by pancreatic CSCs isolated from Pankras/p53 mice. The combination of these drugs also showed superior effects on the expression of proteins involved in cell proliferation, survival and apoptosis. In addition, NVP-LDE-225 co-operated with NVP-BEZ-235 in inhibiting EMT through modulation of cadherin, vimentin and transcription factors Snail, Slug and Zeb1. In conclusion, these data suggest that the combined inhibition of PI3K/Akt/mTOR and Shh pathways may be beneficial for the treatment of pancreatic cancer. PMID:26451606

  11. Methylophiopogonanone A suppresses ischemia/reperfusion-induced myocardial apoptosis in mice via activating PI3K/Akt/eNOS signaling pathway

    PubMed Central

    He, Fei; Xu, Bang-long; Chen, Cai; Jia, Hong-jing; Wu, Ji-xiong; Wang, Xiao-chen; Sheng, Jian-long; Huang, Li; Cheng, Jing

    2016-01-01

    Aim: The dried tuber root of Ophiopogon japonicus has been used in the traditional Chinese medicine for treatment of myocardial ischemia and thrombosis. In this study we investigated the effects of methylophiopogonanone A (MO-A), a major homoisoflavonoid in Ophiopogon japonicus, on myocardial ischemia/reperfusion (I/R) injury. Methods: Mice were pretreated with MO-A (10 mg·kg-1·d-1, po) for 2 weeks and then subjected to transient occlusion of the left anterior descending coronary artery. Cardiac function was evaluated, and the infarct size and apoptosis index were assessed. The mechanisms underlying the cardio-protection of MO-A were analyzed in H9C2 rat cardiomyocytes subjected to hypoxia/reoxygenation (H/R). The cell viability and apoptosis were evaluated; apoptotic and relevant signaling proteins were analyzed. NO levels in the culture medium were assessed. Results: In I/R mice, pretreatment with MO-A significantly reduced the infarct size (by 60.7%) and myocardial apoptosis (by 56.8%), and improved cardiac function. In H9C2 cells subjected to H/R, pretreatment with MO-A (10 μmol/L) significantly decreased apoptosis and cleaved caspase-3 expression, elevated the Bcl-2/Bax ratio and restored NO production. Furthermore, pretreatment with MO-A markedly increased the activation of PI3K/Akt/eNOS pathway in H9C2 cells subjected to H/R, and the protective effects of MO-A were abolished in the presence of the PI3K inhibitor wortmannin (100 nmol/L). Conclusion: MO-A attenuates I/R-induced myocardial apoptosis in mice via activating the PI3K/Akt/eNOS signaling pathway. PMID:27063216

  12. Calcium Signaling Involvement in Cadmium-Induced Astrocyte Cytotoxicity and Cell Death Through Activation of MAPK and PI3K/Akt Signaling Pathways.

    PubMed

    Jiang, Jiao Hua; Ge, Guo; Gao, Kai; Pang, Ying; Chai, Rui Chao; Jia, Xi Hua; Kong, Jin Ge; Yu, Albert Cheung-Hoi

    2015-09-01

    Cadmium (Cd), a highly ubiquitous toxic heavy metal, can contaminate the environment, including agricultural soil, water and air, via industrial runoff and other sources of pollution. Cd accumulated in the body via direct exposure or through the food chain results in neurodegeneration and many other diseases. Previous studies on its toxicity in the central nervous system (CNS) focused mainly on neurons. To obtain a more comprehensive understanding of Cd toxicity for the CNS, we investigated how astrocytes respond to acute and chronic Cd exposure and its toxic molecular mechanisms. When primary cultures of cerebral cortical astrocytes incubated with 1-300 μM CdCl2, morphological changes, LDH release and cell death were observed in a time and dose-dependent manner. Further studies demonstrated that acute and chronic Cd treatment phosphorylated JNK, p38 and Akt to different degrees, while ERK1/2 was only phosphorylated under low doses of Cd (10 μM) exposure. Inhibition of JNK and PI3K/Akt, but not of p38, could partially protect astrocyte from cytotoxicity in chronic and acute Cd exposure. Moreover, Cd also induced a strong calcium signal, while BAPTA, a specific intracellular calcium (Ca(2+)) chelator, prevented Cd-induced intracellular increase of calcium levels in astrocytes; inhibited the Cd-induced activation of ERK1/2, JNK, p38 and Akt; and also significantly reduced astrocyte cell death. All of these results suggested that the Cd-Ca(2+)-MAPK and PI3K/Akt signaling pathways were involved in Cd-induced toxicity in astrocytes. This toxicity involvement indicates that these pathways may be exploited as a target for the prevention of Cd-induced neurodegenerative diseases. PMID:26248512

  13. PI3K/AKT/mTOR and sonic hedgehog pathways cooperate together to inhibit human pancreatic cancer stem cell characteristics and tumor growth.

    PubMed

    Sharma, Narinder; Nanta, Rajesh; Sharma, Jay; Gunewardena, Sumedha; Singh, Karan P; Shankar, Sharmila; Srivastava, Rakesh K

    2015-10-13

    Cancer stem cells (CSCs) play major roles in cancer initiation, progression, and metastasis. It is evident from growing reports that PI3K/Akt/mTOR and Sonic Hedgehog (Shh) signaling pathways are aberrantly reactivated in pancreatic CSCs. Here, we examined the efficacy of combining NVP-LDE-225 (PI3K/mTOR inhibitor) and NVP-BEZ-235 (Smoothened inhibitor) on pancreatic CSCs characteristics, microRNA regulatory network, and tumor growth. NVP-LDE-225 co-operated with NVP-BEZ-235 in inhibiting pancreatic CSC's characteristics and tumor growth in mice by acting at the level of Gli. Combination of NVP-LDE-225 and NVP-BEZ-235 inhibited self-renewal capacity of CSCs by suppressing the expression of pluripotency maintaining factors Nanog, Oct-4, Sox-2 and c-Myc, and transcription of Gli. NVP-LDE-225 co-operated with NVP-BEZ-235 to inhibit Lin28/Let7a/Kras axis in pancreatic CSCs. Furthermore, a superior interaction of these drugs was observed on spheroid formation by pancreatic CSCs isolated from Pankras/p53 mice. The combination of these drugs also showed superior effects on the expression of proteins involved in cell proliferation, survival and apoptosis. In addition, NVP-LDE-225 co-operated with NVP-BEZ-235 in inhibiting EMT through modulation of cadherin, vimentin and transcription factors Snail, Slug and Zeb1. In conclusion, these data suggest that the combined inhibition of PI3K/Akt/mTOR and Shh pathways may be beneficial for the treatment of pancreatic cancer. PMID:26451606

  14. Crosstalk between Meg3 and miR-1297 regulates growth of testicular germ cell tumor through PTEN/PI3K/AKT pathway.

    PubMed

    Yang, Nian-Qin; Luo, Xiao-Jin; Zhang, Jian; Wang, Guo-Min; Guo, Jian-Ming

    2016-01-01

    Maternally Expressed Gene 3 (Meg3) encodes a long non-coding RNA that has been recently shown to regulate tumorigenesis through its interaction with microRNA (miR). We have recently reported that miR-1297 might play a role in the regulation of PTEN/PI3k/Akt signaling pathway in testicular germ cell tumor (TGCT). However, a crosstalk between Meg3 and miR-1297 in TGCT has not been appreciated. Here, we analyzed the levels of Meg3, miR-1297 and PTEN in TGCT specimens, compared to paired adjacent non-tumor tissue (NT), and found that Meg3 levels were significantly decreased and miR-1297 levels were unchanged in TGCT. PTEN protein but not mRNA levels significantly decreased in TGCT. Bioinformatics analyses showed that miR-1297 bound to 3'-UTR of PTEN mRNA, while miR-1297 also bound to Meg3. Luciferase report assay showed that Meg3 overexpression abolished the effects of miR-1297 on 3'-UTR of PTEN mRNA, possibly through competitive binding, which was supported by double fluorescent in situ hybridization showing co-localization of intracellular Meg3 and miR-1297 signals in TGCT cells. Moreover, Meg3 overexpression abolished the inhibitory effects of miR-1297 on PTEN, resulting in deactivation of Akt and decreases in cell growth. Together, these data demonstrate a previous unappreciated pathway in which Crosstalk between Meg3 and miR-1297 regulates growth of TFCT through PTEN/PI3K/AKT signaling. Re-expression of Meg3 may be an attractive strategy for TGCT therapy. PMID:27158395

  15. Calycosin ameliorates diabetes-induced cognitive impairments in rats by reducing oxidative stress via the PI3K/Akt/GSK-3β signaling pathway.

    PubMed

    Wang, Xiang; Zhao, Linhui

    2016-04-29

    Diabetic encephalopathy is one of the most prevalent chronic complications of diabetes mellitus (DM), but there is currently no effective method of prevention nor proven therapeutic regimen for it. In this study, we investigated the effects of calycosin on cognitive behavior and the potential mechanism involved in streptozocin-induced diabetic rats. The effects of diabetes and calycosin treatment on spatial learning and memory were evaluated using the Morris Water Maze, passive avoidance and motor coordination tests. Histological analysis of the hippocampus cornu ammonis 1 (CA1) region was conducted in rats. The decreased expression of the synapsin (SYN) and postsynatptic density protein (PSD-95), as well as brain-derived neurotrophic factor (BDNF) in diabetic rats was measured by quantitative real-time PCR and western blot. Treatment with calycosin promoted a reduction in the expression of SYN, PSD-95 and BDNF. In addition, diabetic rats showed increased MDA levels, and decreased SOD levels and GSH-Px activities in the hippocampus, as well as increased AChE activity in the cerebral cortex; these changes were reversed by calycosin supplementation. Thus, the impairment of learning and memory in STZ-induced diabetic rats was alleviated by calycosin, and that the degree of alleviation was associated with oxidative stress. We also found that calycosin treatment significantly stimulated Akt phosphorylation and decreased GSK-3β and tau phosphorylation, and that these changes could be restored by the PI3K/Akt inhibitor LY294002. In conclusion, calycosin had a beneficial effect on the amelioration, prevention and treatment of diabetes-associated cognitive deficits, through its involvement in oxidative stress, synaptic function and the PI3K/Akt/GSK-3β pathway. PMID:26970304

  16. Hepatocyte growth factor promotes proliferation, invasion, and metastasis of myeloid leukemia cells through PI3K-AKT and MAPK/ERK signaling pathway

    PubMed Central

    Guo, Jiang-Rui; Li, Wei; Wu, Yong; Wu, Lin-Qing; Li, Xin; Guo, Ya-Fei; Zheng, Xiao-Hui; Lian, Xiao-Lan; Huang, Hui-Fang; Chen, Yuan-Zhong

    2016-01-01

    This study aims to investigate effects of HGF expression on biological behaviors of Kasumi-1 and HL60. Expression of HGF and c-Met gene were detected using qRT-PCR. Short hairpin RNA (shRNA) was used to reduce HGF expression. Silencing effect of shRNA was verified by qRT-PCR and western blot. Cell reproductive capacity, cell clonality and cell cycle (apoptosis) were detected by CCK-8, clone formation, flow cytometry (FCM), respectively. Cell adhesion, cell invasion ability and cell proliferation were also examined. Changes of PI3K-AKT, MAPK/ERK signaling factors were detected by western blot. HGF and c-Met expression in first-vist AML group was significantly higher than in AML-relief and normal control group. HGF shRNA can inhibit cell proliferation, inhibit cloning ability. Compared with control group, apoptosis ratios of Kasumi-1 and HL60 cell in interference groups were significantly higher. After shRNA interference, the number of adherent cells and transmembrane cells were significantly decreased compared with control group. Meanwhile, shRNA also down-regulated Bad, Bcl-XL, Bcl-2, CDK1, Cyclin B, MMP2, MMP9, and up-regulated cleaved caspase9, cleaved caspase3, cleaved PARP, Bax, and P21. Moreover, phosphorylated c-Met, AKT, Erk, and mTOR were also reduced. In conclusion, HGF and c-Met gene highly expressed among first-visit AML patients, but decreased after relief treatment. HGF may promote proliferation, invasion, and metastasis of AML cells through PI3K-AKT and MAPK/ERK signaling pathway. Therefore, proliferation and invasion ability of AML cell can be inhibited by down-regulating HGF gene to retardate cell in G2/M stage. PMID:27725846

  17. Telmisartan reduces atrial arrhythmia susceptibility through the regulation of RAS-ERK and PI3K-Akt-eNOS pathways in spontaneously hypertensive rats.

    PubMed

    Wang, Wei-Wei; Zhang, Fei-Long; Chen, Jian-Hua; Chen, Xue-Hai; Fu, Fa-Yuan; Tang, Mi-Rong; Chen, Liang-Long

    2015-08-01

    Telmisartan is an angiotensin II receptor blocker that displays unique PPAR-γ modulating activity. PPAR-γ agonists have been shown to decrease susceptibility to atrial fibrillation through their antioxidant and antiapoptotic effects. The aim of this study was to determine whether telmisartan would have a greater effect on susceptibility to atrial arrhythmia in a hypertensive rat model than valsartan, which is a traditional angiotensin II receptor blocker. In this study, spontaneously hypertensive rats were treated with 10 mg·(kg body mass)(-1)·d(-1) telmisartan (TEL group), 10 mg·(kg body mass)(-1)·d(-1) valsartan (VAL group), or vehicle (saline; SHR group) for 4 weeks. Age-matched Wistar-Kyoto rats (WKY) were used as normotensive controls. After 4 weeks of treatment, we performed echocardiographic assessment, electrophysiological analysis, histological evaluation, and Western blot analysis. Telmisartan decreased systolic blood pressure to a similar extent as valsartan. Relative to the WKY controls, atrial arrhythmia susceptibility was significantly increased in the SHR group, and was significantly decreased by both telmisartan and valsartan, albeit to a greater extent with telmisartan. Arrhythmogenic atrial remodeling, including enlargement of the left atrium, myocyte hypertrophy, interstitial fibrosis, and myocyte apoptosis, was observed in the SHR group, and was accompanied by activated RAS-ERK signaling and suppressed PI3K-Akt-eNOS signaling. The results suggest that telmisartan reduced susceptibility to atrial arrhythmia to a greater extent than valsartan, ameliorated atrial remodeling, and reversed imbalances in the RAS-ERK and PI3K-Akt-eNOS pathways. PMID:26158699

  18. PI3K/Akt and mTOR/p70S6K pathways mediate neuroprotectin D1-induced retinal pigment epithelial cell survival during oxidative stress-induced apoptosis.

    PubMed

    Faghiri, Zahra; Bazan, Nicolas G

    2010-06-01

    The initiation and progression of several forms of retinal degenerations involve excessive, repetitive, and/or sustained oxidative stress that, in turn, mediate photoreceptor cell damage and death. Since phosphatidylinositol 3-kinase (PI3K)/Akt and mTOR/p70S6-kinase pathways are part of survival signaling in cells confronted with oxidative stress, we asked whether or not docosahexaenoic acid-derived neuroprotectin D1 (NPD1) mediates survival upon single-dose and/or repetitive oxidative stress through this pathway. For this purpose, we used human retinal pigment epithelial (ARPE-19) cells challenged by exposure to hydrogen peroxide (H(2)O(2)) plus tumor necrosis factor alpha (TNF-alpha). We found that in single-dose oxidative stress-induced apoptosis, phosphorylation of Akt, mTOR, and p70S6K was both time- and dose- dependent. Inhibition of PI3K or mTOR/p70S6K by wortmannin and rapamycin, respectively, increased apoptosis and inhibited phosphorylation of Akt and p70S6K induced by single-dose oxidative stress. While two exposures of a low dose, non-damaging oxidation induced apoptosis and upregulation of Akt, mTOR, and p70S6K, longer treatment of the cells with three exposures of low dose to low-dose stress showed no changes in the levels of Akt, mTOR, or p70S6K, and resulted in enhanced apoptosis compared to higher doses. Removing the oxidative stress-inducing agents following the single-dose or short term repetitive oxidative stress at the peak of Akt, mTOR, and p70S6K phosphorylation (i.e., 30 min after induction) led to recovery, with no apoptosis after 16 h of incubation. Cells that were induced with three low doses of stress did not show recovery when oxidative stress was removed 30 min after the last exposure. NPD1 protected the RPE cells against both single-dose and repetitive oxidative stress-induced apoptosis and promoted higher levels of phosphorylated Akt, mTOR, and p70S6K. Together, our results show that a) repetitive oxidative stress is dose dependent

  19. 14-3-3ζ up-regulates hypoxia-inducible factor-1α in hepatocellular carcinoma via activation of PI3K/Akt/NF-кB signal transduction pathway

    PubMed Central

    Tang, Yufu; Lv, Pengfei; Sun, Zhongyi; Han, Lei; Luo, Bichao; Zhou, Wenping

    2015-01-01

    14-3-3ζ protein, a member of 14-3-3 family, plays important roles in multiple cellular processes. Our previous study showed that 14-3-3ζ could bind to regulate the expression of hypoxia-inducible factor-1α (HIF-1α), which is induced by hypoxia and a crucial factor for induction of tumor metastasis. Moreover, we also have confirmed the response of 14-3-3ζ to hypoxia in our unpublished data as well. Thus, in the present study, we attempted to reveal that whether the regulation effect of 14-3-3ζ on HIF-1α functioned in a similar pattern as hypoxia. Stable regulation of 14-3-3ζ in human HCC cell line SMMC-772 and HCC-LM3 was achieved. The regulation of 14-3-3ζ on HIF-1α mRNA transcription was evaluated by luciferase activity assay and quantitative real-time PCR (qPCR). The effect of 14-3-3ζ on the production of HIF-1α and pathways determining HIF-1α’s response to hypoxia was assessed using western blotting assay. Our results showed that regulation of 14-3-3ζ expression influenced the activity of HIF-1α, phosphatidyl inositol 3-kinase (PI3K), Akt, extracellular signal-regulated kinase 1/2 (ERK1/2), and nuclear factor kappa B (NF-кB). Blocking of these pathways using indicated inhibitors revealed that 14-3-3ζ enhanced the production of HIF-1α via the activation of PI3K/Akt/NF-кB pathway, which was identical to hypoxia induced HIF-1α expression. For the first time, our study described the key role of 14-3-3ζ in the HIF-1α production in HCC cells. And the molecule exerted its function on HIF-1α both by directly binding to it and via PI3K/Akt/NF-кB signal transduction pathway. PMID:26884855

  20. Anti-proliferative effect of RCE-4 from Reineckia carnea on human cervical cancer HeLa cells by inhibiting the PI3K/Akt/mTOR signaling pathway and NF-κB activation.

    PubMed

    Bai, Caihong; Yang, Xiaojiao; Zou, Kun; He, Haibo; Wang, Junzhi; Qin, Huilin; Yu, Xiaoqin; Liu, Chengxiong; Zheng, Juyan; Cheng, Fan; Chen, Jianfeng

    2016-06-01

    Cervical cancer is the second leading cause of cancer deaths in women worldwide. In recent years, the studies find that inflammation is a critical component of tumor progression, and the ideal therapeutic methods should be aimed at the inflammation reaction triggers. (1β,3β,5β,25S)-spirostan-1,3-diol1-[α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranoside] (RCE-4) was the main active composition of Reineckia carnea (Andr.) Kunth. It significantly induced apoptosis in cervical cancer Caski cells through the mitochondrial pathway in our previous studies; however, its underlying mechanism remains poorly understood. This study aimed to further evaluate the effect of RCE-4 on human cervical cancer HeLa cells. Based on this observation, we investigated the anti-cervical cancer effect of RCE-4 by modulating phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway, nuclear factor-kappa B (NF-κB) activation, and inflammation-related key factors in HeLa cells. The results indicated that the HeLa cell was the most sensitive with an IC50 of 7.01 μM; RCE-4 significantly promoted the release of cellular lactate dehydrogenase (LDH); increased DNA fragmentation and apoptosis; reduced PI3K, Akt, mTOR, and NF-κBp65 phosphorylation levels; increased the Bax and cleaved poly (ADP-ribose) polymerase (PARP) protein levels; suppressed Bcl-2 protein expression; elevated the Bax/Bcl-2 expression ratio; and decreased the interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) mRNA expressions in HeLa cells in a concentration-dependent manner. These findings suggest that RCE-4 exerted beneficially anti-cervical cancer effect on HeLa cells, mainly inhibiting PI3K/Akt/mTOR signaling pathway phosphorylation and NF-κB activation, promoting HeLa cell apoptosis. Graphical abstract Anti-tumor effect of RCE-4 on HeLa cells.

  1. COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

    SciTech Connect

    Kook, Sung-Ho; Lim, Shin-Saeng; Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol; Kwon, Jungkee; Hwang, Jae-Won; Bae, Cheol-Hyeon; Seo, Young-Kwon; Lee, Jeong-Chae

    2014-12-12

    Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways.

  2. Monoclonal Antibody against the Ectodomain of E-Cadherin (DECMA-1) Suppresses Breast Carcinogenesis: Involvement of the HER/PI3K/Akt/mTOR and IAP Pathways

    PubMed Central

    Brouxhon, Sabine M.; Kyrkanides, Stephanos; Teng, Xiaofei; Raja, Veena; O’Banion, M. Kerry; Clarke, Robert; Byers, Stephen; Silberfeld, Andrew; Tornos, Carmen; Ma, Li

    2014-01-01

    Purpose Although targeted therapies against HER2 have been one of the most successful therapeutic strategies for breast cancer, patients eventually developed acquired resistance from compensatory upregulation of alternate HERs and mitogen-activated protein kinase–phosphoinositide 3-kinase (PI3K)/Akt/mTOR signaling. As we and others have shown that the soluble ectodomain fragment of E-cadherin exerts prooncogenic effects via HER1/2–mediated binding and activation of downstream prosurvival pathways, we explored whether targeting this ectodomain [DECMA-1 monoclonal antibody (mAb)] was effective in the treatment of HER2-positive (HER2+) breast cancers. Experimental Design MMTV-PyMT transgenic mice and HER2+/E-cadherin–positive MCF-7 and BT474 trastuzumab-resistant (TtzmR) cells were treated with the DECMA-1 mAb. Antitumor responses were assessed by bromodeoxyuridine incorporation, apoptosis, and necrosis. The underlying intracellular prooncogenic pathways were explored using subcellular fractionation, immunoprecipitation, fluorescence microscopy, and immunoblotting. Results Treatment with DECMA-1 mAb significantly delayed tumor onset and attenuated tumor burden in MMTV-PyMT mice by reducing tumor cell proliferation and inducing apoptosis without any detectable cytotoxicity to mice or end-organs. In vitro treatment of MCF-7 and BT474 TtzmR cells reduced proliferation and induced cancer cell apoptosis. Importantly, this inhibition of breast tumorigenesis was due to concomitant downregulation, via ubiquitin-mediated degradation through the lysosome and proteasome pathways, of all HER family members, components of downstream PI3K/Akt/mTOR prosurvival signaling and suppression of inhibitor of apoptosis proteins. Conclusions Our results establish that the E-cadherin ectodomain-specific mAb DECMA-1 inhibits Ecad+/HER2+ breast cancers by hindering tumor growth and inducing apoptosis via downregulation of key oncogenic pathways involved in trastuzumab resistance, thereby

  3. Timosaponin B-II Ameliorates Palmitate-Induced Insulin Resistance and Inflammation via IRS-1/PI3K/Akt and IKK/NF-[Formula: see text]B Pathways.

    PubMed

    Yuan, Yong-Liang; Lin, Bao-Qin; Zhang, Chun-Feng; Cui, Ling-Ling; Ruan, Shi-Xia; Yang, Zhong-Lin; Li, Fei; Ji, De

    2016-01-01

    This study aimed to investigate the effect of timosaponin B-II (TB-II) on palmitate (PA)-induced insulin resistance and inflammation in HepG2 cells, and probe the potential mechanisms. TB-II, a main ingredient of the traditional Chinese medicine Anemarrhena asphodeloides Bunge, notably ameliorated PA-induced insulin resistance and inflammation, and significantly improved cell viability, decreased PA-induced production of tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]) and interleukin-6 (IL-6) levels. Further, TB-II treatment notably decreased malondialdehyde (MDA) and lactate dehydrogenase (LDH) levels, and improved superoxide dismutase (SOD) and nitric oxide (NO). TB-II also reduced HepG2 cells apoptosis. Insulin receptor substrate-1 (IRS1)/phosphatidylinositol 3-kinase (PI3K)/Akt and inhibitor of nuclear factor [Formula: see text]-B kinase (IKK)/NF-[Formula: see text]B pathways-related proteins, and IKK[Formula: see text], p65 phosphorylation, serine phosphorylation of insulin receptor substrate-1 (IRS-1) at S307, tyrosine phosphorylation of IRS-1, and Akt activation were determined by Western blot. Compared to model group, TB-II significantly downregulated the expression of p-NF-[Formula: see text]Bp65, p-IKK[Formula: see text], p-IRS-1, p-PI3K and p-Akt. TB-II is a promising potential agent for the management of palmitate-induced insulin resistance and inflammation, which might be via IR/IRS-1/PI3K/Akt and IKK/NF-[Formula: see text]B pathways.

  4. Lamin A/C protein is overexpressed in tissue-invading prostate cancer and promotes prostate cancer cell growth, migration and invasion through the PI3K/AKT/PTEN pathway.

    PubMed

    Kong, Lu; Schäfer, Georg; Bu, Huajie; Zhang, Yong; Zhang, Yuxiang; Klocker, Helmut

    2012-04-01

    Prostate cancer (PC) remains the second most common cause of cancer-related death in Western countries. A previous proteomics study suggested that the nuclear membrane protein lamin A/C to be a maker to discriminate low- and high-Gleason score tumors and to identify high-risk cancers. To characterize its function in PC cells, we performed a detailed expression analysis in PC tissue and explored the consequences of down or upregulation of lamin A/C in PC cells. Our results confirm an increased lamin A/C protein expression in high-risk cancers and show association of expression with tumor cell formations at the invasion fronts of tumors and in invasion 'spearheading' tumor cell clusters. In the prostate tumor cell lines, LNCaP, DU145, and PC3 small hairpin RNA knockdown or overexpression of lamin A/C resulted in inhibition or stimulation, respectively, of cell growth, colony formation, migration and invasion. Further mechanism studies suggested that the lamin A/C-related malignant behavior is regulated through modulation of the phosphoinositide 3-kinase (PI3K)/AKT/PTEN signaling pathway. Western blot results indicated that knockdown or overexpression of lamin A/C decreased or increased, respectively, protein levels of the PI3K subunits p110 and p85 in all three cell lines; phosphor-AKT in the PTEN-negative cell lines LNCaP and PC3, and, increased or decreased, respectively, PTEN protein levels in PTEN-positive DU145 cells. Together, our data suggest that lamin A/C proteins are positively involved in malignant behavior of PC cells through the PI3K/AKT/PTEN pathway. Lamin A/C may represent a new oncogenic factor and a novel therapeutic target for PC.

  5. Anti-inflammatory effects of egg white combined with chalcanthite in lipopolysaccharide-stimulated BV2 microglia through the inhibition of NF-κB, MAPK and PI3K/Akt signaling pathways.

    PubMed

    Choi, Eun A; Park, Hye Young; Yoo, Hwa-Seung; Choi, Yung Hyun

    2013-01-01

    Egg white-chalcanthite (EWCC) is a mixture of egg white and chalcanthite prepared by roasting chalcanthite (which is a natural mineral mainly composed of CuSO4•5H2O) to the point of dehydration, pulverizing the dehydrated chalcanthite and then mixing the pulverized chalcanthite to react with egg white to trigger a reaction. When egg white-chalcanthite is prepared in this manner, the toxicity of chalcanthite is neutralized by the egg white, so that the toxicity is reduced or removed and the pharmaceutical properties are increased. However, the cellular and molecular mechanisms underlying the pharmacological activity of EWCC remain poorly understood. In this study, we investigated the inhibitory effects of EWCC on the production of lipopolysaccharide (LPS)-induced pro-inflammatory mediators in BV2 microglia. Our data indicated that the EWCC treatment significantly inhibited the excessive production of nitric oxide and prostaglandin E2 in LPS-stimulated BV2 microglia in a concentration-dependent manner without causing cytotoxicity. It also attenuated the expression of inducible nitric oxide synthase, cyclooxygenase-2 and pro-inflammatory cytokines, including interleukin-1β and tumor necrosis factor-α. Moreover, EWCC exhibited anti-inflammatory properties by the suppression of nuclear factor‑κB (NF-κB) activation by blocking IκB-α degradation, downregulation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt pathways. Our results indicate that the inhibitory effects of EWCC on LPS-stimulated inflammatory mediator production in BV2 microglia are associated with the suppression of the NF-κB, MAPK and PI3K/Akt signaling pathways. These findings suggest that EWCC may offer a substantial therapeutic potential for the treatment of neurodegenerative diseases that are accompanied by microglial activation. PMID:23128312

  6. The CB1 cannabinoid receptor signals striatal neuroprotection via a PI3K/Akt/mTORC1/BDNF pathway

    PubMed Central

    Blázquez, C; Chiarlone, A; Bellocchio, L; Resel, E; Pruunsild, P; García-Rincón, D; Sendtner, M; Timmusk, T; Lutz, B; Galve-Roperh, I; Guzmán, M

    2015-01-01

    The CB1 cannabinoid receptor, the main molecular target of endocannabinoids and cannabis active components, is the most abundant G protein-coupled receptor in the mammalian brain. In particular, the CB1 receptor is highly expressed in the basal ganglia, mostly on terminals of medium-sized spiny neurons, where it plays a key neuromodulatory function. The CB1 receptor also confers neuroprotection in various experimental models of striatal damage. However, the assessment of the physiological relevance and therapeutic potential of the CB1 receptor in basal ganglia-related diseases is hampered, at least in part, by the lack of knowledge of the precise mechanism of CB1 receptor neuroprotective activity. Here, by using an array of pharmacological, genetic and pharmacogenetic (designer receptor exclusively activated by designer drug) approaches, we show that (1) CB1 receptor engagement protects striatal cells from excitotoxic death via the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin complex 1 pathway, which, in turn, (2) induces brain-derived neurotrophic factor (BDNF) expression through the selective activation of BDNF gene promoter IV, an effect that is mediated by multiple transcription factors. To assess the possible functional impact of the CB1/BDNF axis in a neurodegenerative-disease context in vivo, we conducted experiments in the R6/2 mouse, a well-established model of Huntington's disease, in which the CB1 receptor and BDNF are known to be severely downregulated in the dorsolateral striatum. Adeno-associated viral vector-enforced re-expression of the CB1 receptor in the dorsolateral striatum of R6/2 mice allowed the re-expression of BDNF and the concerted rescue of the neuropathological deficits in these animals. Collectively, these findings unravel a molecular link between CB1 receptor activation and BDNF expression, and support the relevance of the CB1/BDNF axis in promoting striatal neuron survival. PMID:25698444

  7. The CB₁ cannabinoid receptor signals striatal neuroprotection via a PI3K/Akt/mTORC1/BDNF pathway.

    PubMed

    Blázquez, C; Chiarlone, A; Bellocchio, L; Resel, E; Pruunsild, P; García-Rincón, D; Sendtner, M; Timmusk, T; Lutz, B; Galve-Roperh, I; Guzmán, M

    2015-10-01

    The CB1 cannabinoid receptor, the main molecular target of endocannabinoids and cannabis active components, is the most abundant G protein-coupled receptor in the mammalian brain. In particular, the CB1 receptor is highly expressed in the basal ganglia, mostly on terminals of medium-sized spiny neurons, where it plays a key neuromodulatory function. The CB1 receptor also confers neuroprotection in various experimental models of striatal damage. However, the assessment of the physiological relevance and therapeutic potential of the CB1 receptor in basal ganglia-related diseases is hampered, at least in part, by the lack of knowledge of the precise mechanism of CB1 receptor neuroprotective activity. Here, by using an array of pharmacological, genetic and pharmacogenetic (designer receptor exclusively activated by designer drug) approaches, we show that (1) CB1 receptor engagement protects striatal cells from excitotoxic death via the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin complex 1 pathway, which, in turn, (2) induces brain-derived neurotrophic factor (BDNF) expression through the selective activation of BDNF gene promoter IV, an effect that is mediated by multiple transcription factors. To assess the possible functional impact of the CB1/BDNF axis in a neurodegenerative-disease context in vivo, we conducted experiments in the R6/2 mouse, a well-established model of Huntington's disease, in which the CB1 receptor and BDNF are known to be severely downregulated in the dorsolateral striatum. Adeno-associated viral vector-enforced re-expression of the CB1 receptor in the dorsolateral striatum of R6/2 mice allowed the re-expression of BDNF and the concerted rescue of the neuropathological deficits in these animals. Collectively, these findings unravel a molecular link between CB1 receptor activation and BDNF expression, and support the relevance of the CB1/BDNF axis in promoting striatal neuron survival.

  8. Adiponectin promotes VEGF-A-dependent angiogenesis in human chondrosarcoma through PI3K, Akt, mTOR, and HIF-α pathway

    PubMed Central

    Shih, Jhao-Sheng; Fong, Yi-Chin; Wang, Shih-Wei; Li, Te-Mao; Tang, Chih-Hsin

    2015-01-01

    Chondrosarcoma is a type of highly malignant tumor with a potent capacity to invade locally and cause distant metastasis. Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes. On the other hand, angiogenesis is a critical step in tumor growth and metastasis. However, the relationship of adiponectin with vascular endothelial growth factor-A (VEGF-A) expression and angiogenesis in human chondrosarcoma is mostly unknown. In this study we first demonstrated that the expression of adiponectin was correlated with tumor stage of human chondrosarcoma tissues. In addition, we also found that adiponectin increased VEGF-A expression in human chondrosarcoma cells and subsequently induced migration and tube formation in human endothelial progenitor cells (EPCs). Adiponectin promoted VEGF-A expression through adiponectin receptor (AdipoR), phosphoinositide 3 kinase (PI3K), Akt, mammalian target of rapamycin (mTOR), and hypoxia-inducible factor-1α (HIF)-1α signaling cascades. Knockdown of adiponectin decreased VEGF-A expression and also abolished chondrosarcoma conditional medium-mediated tube formation in EPCs in vitro as well as angiogenesis effects in the chick chorioallantoic membrane and Matrigel plug nude mice model in vivo. Therefore, adiponectin is crucial for tumor angiogenesis and growth, which may represent a novel target for anti-angiogenic therapy in human chondrosarcoma. PMID:26468982

  9. Resveratrol Regulates Activated Hepatic Stellate Cells by Modulating NF-κB and the PI3K/Akt Signaling Pathway.

    PubMed

    Zhang, De-Quan; Sun, Peng; Jin, Quan; Li, Xia; Zhang, Yu; Zhang, Yu-Jing; Wu, Yan-Ling; Nan, Ji-Xing; Lian, Li-Hua

    2016-01-01

    In the present study, we investigated whether resveratrol could suppress the hepatic fibrogenesis in activated hepatic stellate cells. The immortalized rat hepatic stellate cells, t-HSC/Cl-6, were treated with resveratrol 1 h prior to lipopolysaccharide (LPS, 1 μg/mL). Resveratrol decreased t-HSC/Cl-6 cell viability at much lower concentrations within 24 h. Resveratrol pretreatment also decreased the LPS-induced protein expression of α-SMA and collagen I. In addition, resveratrol significantly reduced the protein expression of Toll-like receptor 4 (TLR4) and myeloid differentiation primary response gene 88 (MyD88), and the expression of phosphorylated phosphatidylinositol 3-kinase (PI3K) and phosphorylated serine/threonine kinase B (Akt). Moreover, resveratrol markedly blocked the translocation of nuclear factor (NF)-κB in LPS-activated HSCs. Furthermore, resveratrol inhibited HSCs activation through stimulating LXRβ, but did not influence LXRα. Overall, we conclude that the antifibrotic effect of resveratrol is the result of blocking NF-κB activation and PI3K/Akt phosphorylation, which inhibits HSC activation to obstruct liver fibrosis. Thus, resveratrol may be a natural agent for preventing hepatic fibrosis.

  10. The role of PI3K/Akt in human herpesvirus infection: From the bench to the bedside.

    PubMed

    Liu, XueQiao; Cohen, Jeffrey I

    2015-05-01

    The phosphatidylinositol-3-kinase (PI3K)-Akt signaling pathway regulates several key cellular functions including protein synthesis, cell growth, glucose metabolism, and inflammation. Many viruses have evolved mechanisms to manipulate this signaling pathway to ensure successful virus replication. The human herpesviruses undergo both latent and lytic infection, but differ in cell tropism, growth kinetics, and disease manifestations. Herpesviruses express multiple proteins that target the PI3K/Akt cell signaling pathway during the course of their life cycle to facilitate viral infection, replication, latency, and reactivation. Rare human genetic disorders with mutations in either the catalytic or regulatory subunit of PI3K that result in constitutive activation of the protein predispose to severe herpesvirus infections as well as to virus-associated malignancies. Inhibiting the PI3K/Akt pathway or its downstream proteins using drugs already approved for other diseases can block herpesvirus lytic infection and may reduce malignancies associated with latent herpesvirus infections. PMID:25798530

  11. The Role of PI3K/Akt in Human Herpesvirus Infection: from the Bench to the Bedside

    PubMed Central

    Liu, XueQiao; Cohen, Jeffrey I.

    2015-01-01

    The phosphatidylinositol-3-kinase (PI3K)-Akt signaling pathway regulates several key cellular functions including protein synthesis, cell growth, glucose metabolism, and inflammation. Many viruses have evolved mechanisms to manipulate this signaling pathway to ensure successful virus replication. The human herpesviruses undergo both latent and lytic infection, but differ in cell tropism, growth kinetics, and disease manifestations. Herpesviruses express multiple proteins that target the PI3K/Akt cell signaling pathway during the course of their life cycle to facilitate viral infection, replication, latency, and reactivation. Rare human genetic disorders with mutations in either the catalytic or regulatory subunit of PI3K that result in constitutive activation of the protein predispose to severe herpesvirus infections as well as to virus-associated malignancies. Inhibiting the PI3K/Akt pathway or its downstream proteins using drugs already approved for other diseases can block herpesvirus lytic infection and may reduce malignancies associated with latent herpesvirus infections. PMID:25798530

  12. Soyasaponins can blunt inflammation by inhibiting the reactive oxygen species-mediated activation of PI3K/Akt/NF-kB pathway.

    PubMed

    Zha, Longying; Chen, Jiading; Sun, Suxia; Mao, Limei; Chu, Xinwei; Deng, Hong; Cai, Junwei; Li, Xuefeng; Liu, Zhenqi; Cao, Wenhong

    2014-01-01

    We and others have recently shown that soyasaponins abundant in soybeans can decrease inflammation by suppressing the nuclear factor kappa B (NF-kB)-mediated inflammation. However, the exact molecular mechanisms by which soyasaponins inhibit the NF-kB pathway have not been established. In this study in macrophages, soyasaponins (A1, A2 and I) inhibited the lipopolysaccharide (LPS)-induced release of inflammatory marker prostaglandin E2 (PGE2) to a similar extent as the NF-kB inhibitor (BAY117082). Soyasaponins (A1, A2 and I) also suppressed the LPS-induced expression of cyclooxygenase 2 (COX-2), another inflammatory marker, in a dose-dependent manner by inhibiting NF-kB activation. In defining the associated mechanisms, we found that soyasaponins (A1, A2 and I) blunted the LPS-induced IKKα/β phosphorylation, IkB phosphorylation and degradation, and NF-kB p65 phosphorylation and nuclear translocation. In studying the upstream targets of soyasaponins on the NF-kB pathway, we found that soyasaponins (A1, A2 and I) suppressed the LPS-induced activation of PI3K/Akt similarly as the PI3K inhibitor LY294002, which alone blocked the LPS-induced activation of NF-kB. Additionally, soyasaponins (A1, A2 and I) reduced the LPS-induced production of reactive oxygen species (ROS) to the same extent as the anti-oxidant N-acetyl-L-cysteine, which alone inhibited the LPS-induced phosphorylation of Akt, IKKα/β, IkBα, and p65, transactivity of NF-kB, PGE2 production, and malondialdehyde production. Finally, our results show that soyasaponins (A1, A2 and I) elevated SOD activity and the GSH/GSSG ratio. Together, these results show that soyasaponins (A1, A2 and I) can blunt inflammation by inhibiting the ROS-mediated activation of the PI3K/Akt/NF-kB pathway. PMID:25233217

  13. Soyasaponins Can Blunt Inflammation by Inhibiting the Reactive Oxygen Species-Mediated Activation of PI3K/Akt/NF-kB Pathway

    PubMed Central

    Zha, Longying; Chen, Jiading; Sun, Suxia; Mao, Limei; Chu, Xinwei; Deng, Hong; Cai, Junwei; Li, Xuefeng; Liu, Zhenqi; Cao, Wenhong

    2014-01-01

    We and others have recently shown that soyasaponins abundant in soybeans can decrease inflammation by suppressing the nuclear factor kappa B (NF-kB)-mediated inflammation. However, the exact molecular mechanisms by which soyasaponins inhibit the NF-kB pathway have not been established. In this study in macrophages, soyasaponins (A1, A2 and I) inhibited the lipopolysaccharide (LPS)-induced release of inflammatory marker prostaglandin E2 (PGE2) to a similar extent as the NF-kB inhibitor (BAY117082). Soyasaponins (A1, A2 and I) also suppressed the LPS-induced expression of cyclooxygenase 2 (COX-2), another inflammatory marker, in a dose-dependent manner by inhibiting NF-kB activation. In defining the associated mechanisms, we found that soyasaponins (A1, A2 and I) blunted the LPS-induced IKKα/β phosphorylation, IkB phosphorylation and degradation, and NF-kB p65 phosphorylation and nuclear translocation. In studying the upstream targets of soyasaponins on the NF-kB pathway, we found that soyasaponins (A1, A2 and I) suppressed the LPS-induced activation of PI3K/Akt similarly as the PI3K inhibitor LY294002, which alone blocked the LPS-induced activation of NF-kB. Additionally, soyasaponins (A1, A2 and I) reduced the LPS-induced production of reactive oxygen species (ROS) to the same extent as the anti-oxidant N-acetyl-L-cysteine, which alone inhibited the LPS-induced phosphorylation of Akt, IKKα/β, IkBα, and p65, transactivity of NF-kB, PGE2 production, and malondialdehyde production. Finally, our results show that soyasaponins (A1, A2 and I) elevated SOD activity and the GSH/GSSG ratio. Together, these results show that soyasaponins (A1, A2 and I) can blunt inflammation by inhibiting the ROS-mediated activation of the PI3K/Akt/NF-kB pathway. PMID:25233217

  14. Soyasaponins can blunt inflammation by inhibiting the reactive oxygen species-mediated activation of PI3K/Akt/NF-kB pathway.

    PubMed

    Zha, Longying; Chen, Jiading; Sun, Suxia; Mao, Limei; Chu, Xinwei; Deng, Hong; Cai, Junwei; Li, Xuefeng; Liu, Zhenqi; Cao, Wenhong

    2014-01-01

    We and others have recently shown that soyasaponins abundant in soybeans can decrease inflammation by suppressing the nuclear factor kappa B (NF-kB)-mediated inflammation. However, the exact molecular mechanisms by which soyasaponins inhibit the NF-kB pathway have not been established. In this study in macrophages, soyasaponins (A1, A2 and I) inhibited the lipopolysaccharide (LPS)-induced release of inflammatory marker prostaglandin E2 (PGE2) to a similar extent as the NF-kB inhibitor (BAY117082). Soyasaponins (A1, A2 and I) also suppressed the LPS-induced expression of cyclooxygenase 2 (COX-2), another inflammatory marker, in a dose-dependent manner by inhibiting NF-kB activation. In defining the associated mechanisms, we found that soyasaponins (A1, A2 and I) blunted the LPS-induced IKKα/β phosphorylation, IkB phosphorylation and degradation, and NF-kB p65 phosphorylation and nuclear translocation. In studying the upstream targets of soyasaponins on the NF-kB pathway, we found that soyasaponins (A1, A2 and I) suppressed the LPS-induced activation of PI3K/Akt similarly as the PI3K inhibitor LY294002, which alone blocked the LPS-induced activation of NF-kB. Additionally, soyasaponins (A1, A2 and I) reduced the LPS-induced production of reactive oxygen species (ROS) to the same extent as the anti-oxidant N-acetyl-L-cysteine, which alone inhibited the LPS-induced phosphorylation of Akt, IKKα/β, IkBα, and p65, transactivity of NF-kB, PGE2 production, and malondialdehyde production. Finally, our results show that soyasaponins (A1, A2 and I) elevated SOD activity and the GSH/GSSG ratio. Together, these results show that soyasaponins (A1, A2 and I) can blunt inflammation by inhibiting the ROS-mediated activation of the PI3K/Akt/NF-kB pathway.

  15. Accelerated Tumor Growth Mediated by Sub-lytic Levels of Antibody-Induced Complement Activation is Associated with Activation of the PI3K/AKT Survival Pathway

    PubMed Central

    Wu, Xiaohong; Ragupathi, Govind; Panageas, Katherine; Hong, Feng; Livingston, Philip O.

    2013-01-01

    Purpose We addressed the possibility that low levels of tumor cell bound antibodies targeting gangliosides might accelerate tumor growth. Experimental Design To test this hypothesis, we treated mice with a range of mAb doses against GM2, GD2, GD3 and CD20 after challenge with tumors expressing these antigens and tested the activity of the same mAbs in-vitro. We also explored the mechanisms behind the complement-mediated tumor growth acceleration that we observed and an approach to overcome it. Results Serologically detectable levels of IgM-mAb against GM2 are able to delay or prevent tumor growth of high GM2-expressing cell lines both in-vitro and in a SCID mouse model, while very low levels of this mAb resulted in slight but consistent acceleration of tumor growth in both settings. Surprisingly, this is not restricted to IgM antibodies targeting GM2 but consistent against IgG-mAb targeting GD3 as well. These findings were mirrored by in-vitro studies with antibodies against these antigens as well as GD2 and CD20 (with Rituxan), and shown to be complement-dependent in all cases. Complement-mediated accelerated growth of cultured tumor cell lines initiated by low mAb levels was associated with activation of the PI3K/AKT survival pathway and significantly elevated levels of both p-AKT and p-PRAS40. This complement-mediated PI3K-activation and accelerated tumor growth in-vitro and in-vivo are eliminated by PI3K-inhibitors NVP-BEZ235 and Wortmannin. These PI3K-inhibitors also significantly increased efficacy of high doses of these 4 mAbs. Conclusion Our findings suggest that manipulation of the PI3K/AKT pathway and its signaling network can significantly increase the potency of passively administered mAbs and vaccine-induced-antibodies targeting a variety of tumor-cell-surface-antigens. PMID:23833306

  16. The PI3K/Akt and ERK pathways elevate thyroid hormone receptor β1 and TRH receptor to decrease thyroid hormones after exposure to PCB153 and p,p'-DDE.

    PubMed

    Liu, Changjiang; Li, Lianbing; Ha, Mei; Qi, Suqin; Duan, Peng; Yang, Kedi

    2015-01-01

    PCBs and DDT cause the disturbance of thyroid hormone (TH) homeostasis in humans and animals. To test the hypothesis that the PI3K/Akt and MAPK pathways would play significant roles in TH imbalance caused by PCBs and DDT, Sprague-Dawley rats were dosed with PCB153 and p,p'-DDE intraperitoneally for 5 consecutive days, and human thyroid follicular epithelial (Nthy-ori 3-1 cell line) were treated with PCB153 and p,p'-DDE for different time. Results showed that serum total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3) and thyroid stimulating hormone (TSH) were decreased, whereas serum free triiodothyronine (FT3) and thyrotropin releasing hormone (TRH) were not changed. The PI3K/Akt and ERK pathways were activated in vivo and in vitro after the treatment with PCB153 and p,p'-DDE. Moreover, TH receptor β1 (TRβ1) was elevated after the activation of the PI3K/Akt pathway and was depressed after the inhibition of the PI3K/Akt pathway; TRH receptor (TRHr) was increased after the activation of the ERK pathway and was decreased after the inhibition of the ERK pathway. Though TH receptor α1 (TRα1) level was increased in the hypothalamus, TRα1 and TSHr were not influenced by the status of signaling pathways in in vitro study. Taken together, after exposure to PCB153 and p,p'-DDE, activated PI3K/Akt and ERK pathways disrupt the hypothalamic-pituitary-thyroid (HPT) axis via TRβ1 and TRHr and then decrease TH levels, and that would be a potential mechanism by which PCBs and DDT disturb TH homeostasis.

  17. Quercetin 3-O-methyl ether protects FL83B cells from copper induced oxidative stress through the PI3K/Akt and MAPK/Erk pathway

    SciTech Connect

    Tseng, Hsiao-Ling; Li, Chia-Jung; Huang, Lin-Huang; Chen, Chun-Yao; Tsai, Chun-Hao; Lin, Chun-Nan; Hsu, Hsue-Yin

    2012-10-01

    Quercetin is a bioflavonoid that exhibits several biological functions in vitro and in vivo. Quercetin 3-O-methyl ether (Q3) is a natural product reported to have pharmaceutical activities, including antioxidative and anticancer activities. However, little is known about the mechanism by which it protects cells from oxidative stress. This study was designed to investigate the mechanisms by which Q3 protects against Cu{sup 2+}-induced cytotoxicity. Exposure to Cu{sup 2+} resulted in the death of mouse liver FL83B cells, characterized by apparent apoptotic features, including DNA fragmentation and increased nuclear condensation. Q3 markedly suppressed Cu{sup 2+}-induced apoptosis and mitochondrial dysfunction, characterized by reduced mitochondrial membrane potential, caspase-3 activation, and PARP cleavage, in Cu{sup 2+}-exposed cells. The involvement of PI3K, Akt, Erk, FOXO3A, and Mn-superoxide dismutase (MnSOD) was shown to be critical to the survival of Q3-treated FL83B cells. The liver of both larval and adult zebrafish showed severe damage after exposure to Cu{sup 2+} at a concentration of 5 μM. Hepatic damage induced by Cu{sup 2+} was reduced by cotreatment with Q3. Survival of Cu{sup 2+}-exposed larval zebrafish was significantly increased by cotreatment with 15 μM Q3. Our results indicated that Cu{sup 2+}-induced apoptosis in FL83B cells occurred via the generation of ROS, upregulation and phosphorylation of Erk, overexpression of 14-3-3, inactivation of Akt, and the downregulation of FOXO3A and MnSOD. Hence, these results also demonstrated that Q3 plays a protective role against oxidative damage in zebrafish liver and remarked the potential of Q3 to be used as an antioxidant for hepatocytes. Highlights: ► Protective effects of Q3 on Cu{sup 2+}-induced oxidative stress in vitro and in vivo. ► Cu{sup 2+} induced apoptosis in FL83B cells via ROS and the activation of Erk. ► Q3 abolishes Cu{sup 2+}-induced apoptosis through the PI3K/Akt and MAPK

  18. An Invertebrate Warburg Effect: A Shrimp Virus Achieves Successful Replication by Altering the Host Metabolome via the PI3K-Akt-mTOR Pathway

    PubMed Central

    Su, Mei-An; Huang, Yun-Tzu; Chen, I-Tung; Lee, Der-Yen; Hsieh, Yun-Chieh; Li, Chun-Yuan; Ng, Tze Hann; Liang, Suh-Yuen; Lin, Shu-Yu; Huang, Shiao-Wei; Chiang, Yi-An; Yu, Hon-Tsen; Khoo, Kay-Hooi; Chang, Geen-Dong; Lo, Chu-Fang; Wang, Han-Ching

    2014-01-01

    In this study, we used a systems biology approach to investigate changes in the proteome and metabolome of shrimp hemocytes infected by the invertebrate virus WSSV (white spot syndrome virus) at the viral genome replication stage (12 hpi) and the late stage (24 hpi). At 12 hpi, but not at 24 hpi, there was significant up-regulation of the markers of several metabolic pathways associated with the vertebrate Warburg effect (or aerobic glycolysis), including glycolysis, the pentose phosphate pathway, nucleotide biosynthesis, glutaminolysis and amino acid biosynthesis. We show that the PI3K-Akt-mTOR pathway was of central importance in triggering this WSSV-induced Warburg effect. Although dsRNA silencing of the mTORC1 activator Rheb had only a relatively minor impact on WSSV replication, in vivo chemical inhibition of Akt, mTORC1 and mTORC2 suppressed the WSSV-induced Warburg effect and reduced both WSSV gene expression and viral genome replication. When the Warburg effect was suppressed by pretreatment with the mTOR inhibitor Torin 1, even the subsequent up-regulation of the TCA cycle was insufficient to satisfy the virus's requirements for energy and macromolecular precursors. The WSSV-induced Warburg effect therefore appears to be essential for successful viral replication. PMID:24945378

  19. Fisetin inhibits UVB-induced cutaneous inflammation and activation of PI3K/AKT/NFκB signaling pathways in SKH-1 hairless mice.

    PubMed

    Pal, Harish Chandra; Athar, Mohammad; Elmets, Craig A; Afaq, Farrukh

    2015-01-01

    Solar ultraviolet B (UVB) radiation has been shown to induce inflammation, DNA damage, p53 mutations and alterations in signaling pathways eventually leading to skin cancer. In this study, we investigated whether fisetin reduces inflammatory responses and modulates PI3K/AKT/NFκB cell survival signaling pathways in UVB-exposed SKH-1 hairless mouse skin. Mice were exposed to 180 mJ cm(-2) of UVB radiation on alternate days for a total of seven exposures, and fisetin (250 and 500 nmol) was applied topically after 15 min of each UVB exposure. Fisetin treatment to UVB-exposed mice resulted in decreased hyperplasia and reduced infiltration of inflammatory cells. Fisetin treatment also reduced inflammatory mediators such as COX-2, PGE2 as well as its receptors (EP1-EP4) and MPO activity. Furthermore, fisetin reduced the level of inflammatory cytokines TNFα, IL-1β and IL-6 in UVB-exposed skin. Fisetin treatment also reduced cell proliferation markers as well as DNA damage as evidenced by increased expression of p53 and p21 proteins. Further studies revealed that fisetin inhibited UVB-induced expression of PI3K, phosphorylation of AKT and activation of the NFκB signaling pathway in mouse skin. Overall, these data suggest that fisetin may be useful against UVB-induced cutaneous inflammation and DNA damage.

  20. Targeting AKT1-E17K and the PI3K/AKT Pathway with an Allosteric AKT Inhibitor, ARQ 092

    PubMed Central

    Yu, Yi; Savage, Ronald E.; Eathiraj, Sudharshan; Meade, Justin; Wick, Michael J.; Hall, Terence; Abbadessa, Giovanni; Schwartz, Brian

    2015-01-01

    As a critical component in the PI3K/AKT/mTOR pathway, AKT has become an attractive target for therapeutic intervention. ARQ 092 and a next generation AKT inhibitor, ARQ 751 are selective, allosteric, pan-AKT and AKT1-E17K mutant inhibitors that potently inhibit phosphorylation of AKT. Biochemical and cellular analysis showed that ARQ 092 and ARQ 751 inhibited AKT activation not only by dephosphorylating the membrane-associated active form, but also by preventing the inactive form from localizing into plasma membrane. In endometrial PDX models harboring mutant AKT1-E17K and other tumor models with an activated AKT pathway, both compounds exhibited strong anti-tumor activity. Combination studies conducted in in vivo breast tumor models demonstrated that ARQ 092 enhanced tumor inhibition of a common chemotherapeutic agent (paclitaxel). In a large panel of diverse cancer cell lines, ARQ 092 and ARQ 751 inhibited proliferation across multiple tumor types but were most potent in leukemia, breast, endometrial, and colorectal cancer cell lines. Moreover, inhibition by ARQ 092 and ARQ 751 was more prevalent in cancer cell lines containing PIK3CA/PIK3R1 mutations compared to those with wt-PIK3CA/PIK3R1 or PTEN mutations. For both ARQ 092 and ARQ 751, PIK3CA/PIK3R1 and AKT1-E17K mutations can potentially be used as predictive biomarkers for patient selection in clinical studies. PMID:26469692

  1. Naoxintong Protects Primary Neurons from Oxygen-Glucose Deprivation/Reoxygenation Induced Injury through PI3K-Akt Signaling Pathway

    PubMed Central

    Zhao, Pei; Zhu, Jinqiang; Yan, Chen; Li, Lin; Zhang, Han; Zhang, Meng; Gao, Xiumei

    2016-01-01

    Naoxintong capsule (NXT), developed from Buyang Huanwu Decoction, has shown the neuroprotective effects in cerebrovascular diseases, but the neuroprotection mechanisms of NXT on ischemia/reperfusion injured neurons have not yet been well known. In this study, we established the oxygen-glucose deprivation/reoxygenation (OGD/R) induced neurons injury model and treat the neurons with cerebrospinal fluid containing NXT (BNC) to investigate the effects of NXT on OGD/R induced neurons injury and potential mechanisms. BNC improved neuron viability and decreased apoptotic rate induced by OGD/R. BNC attenuated OGD/R induced cytosolic and mitochondrial Ca2+ overload, ROS generation, intracellular NO levels and nNOS mRNA increase, and cytochrome-c release when compared with OGD/R group. BNC significantly inhibited both mPTP opening and ΔΨm depolarization. BNC increased Bcl-2 expression and decreased Bax expression, upregulated the Bcl-2/Bax ratio, downregulated caspase-3 mRNA and caspase-9 mRNA expression, and decreased cleaved caspase-3 expression and caspase-3 activity. BNC increased phosphorylation of Akt following OGD/R, while LY294002 attenuated BNC induced increase of phosphorylated Akt expression. Our study demonstrated that NXT protected primary neurons from OGD/R induced injury by inhibiting calcium overload and ROS generation, protecting mitochondria, and inhibiting mitochondrial apoptotic pathway which was mediated partially by PI3K-Akt signaling pathway activation. PMID:26949405

  2. Gadolinium promoted proliferation in mouse embryo fibroblast NIH3T3 cells through Rac and PI3K/Akt signaling pathways.

    PubMed

    Shen, Liming; Yang, Aochu; Yao, Pengwei; Sun, Xiaohong; Chen, Cheng; Mo, Cuiping; Shi, Lei; Chen, Youjiao; Liu, Qiong

    2014-08-01

    Nephrogenic systemic fibrosis (NSF) is a fibrosing disorder disease developed in patients with underlying renal insufficiency following exposure to gadolinium-based contrast agents (GBCAs). Previous studies have demonstrated that GdCl3 can promote NIH3T3 fibroblast cell proliferation, which provide a new clue to the role of GBCAs in the development of NSF. In the present study, we further clarify the molecular mechanism of Gd-promoted proliferation. The results showed that intervention with the Rac inhibitor NSC23766 abrogated Gd-promoted proliferation. The levels of active Rac1 significantly increased in Gd-treated cells detected by pull-down assays. In addition, the phosphorylation of Akt was significantly elevated in the treatment group, which was blocked by NSC23766. NSC23766 also reduced the migration of NIH3T3 cells enhanced by Gd. Moreover, the F-actin cytoskeleton was strengthened and the mitotic cell numbers was significantly increased after exposure to Gd. These results suggest that Rac and PI3K/Akt signaling pathways, as well as integrin-mediated signal pathway may play important roles in Gd-induced cell proliferation. In addition, under serum-free condition, Gd could decrease ROS accumulation and increase NIH3T3 cell survival.

  3. Medroxyprogestogen enhances apoptosis of SKOV-3 cells via inhibition of the PI3K/Akt signaling pathway

    PubMed Central

    Li, Yan; Jiang, Yi; Wan, Yicong; Zhang, Lin; Tang, Weiwei; Ma, Jingjing; Wu, Shan; Cheng, Wenjun

    2013-01-01

    We sought to assess the effect of progestin on the apoptosis of epithelial ovarian cancer cell line SKOV-3 and via regulation of phosphorylation signaling in. Epithelial ovarian cancer cell line SKOV-3 was treated with medroxyprogestogen, phosphatidylinositol 3-kinase inhibitor LY294002 and vehicle control. Akt, phospho-Akt, Bcl-2 and phospho-Bad proteins were examined by immunoblotting assays. Medroxyprogestogen-induced apoptosis was assessed by MTT assays and Annexin V apoptosis assay. We found no significant difference in Akt and Bad expression in both the medroxyprogestogen groups and the control group. The levels of phospho-Akt, Bcl-2 and phospho-Bad were decreased in all the medroxyprogestogen groups and significantly decreased in the high dose mitogen-activated protein (MAP) group (10 µmol/L). Viability of SKOV-3 was reduced and apparent apoptosis of SKOV-3 cells was observed with increased doses of MAP. The findings suggest that medroxyprogestogen can induce SKOV-3 cell apoptosis by inhibiting Akt phosphorylation. PMID:23554793

  4. Fangchinoline targets PI3K and suppresses PI3K/AKT signaling pathway in SGC7901 cells

    PubMed Central

    TIAN, FENG; DING, DING; LI, DANDAN

    2015-01-01

    Fangchinoline, an important compound in Stephania tetrandra S. Moore, as a novel antitumor agent, has been implicated in several types of cancers cells except gastric cancer. To investigate whether fangchinoline affects gastric cancer cells, we detected the signaling pathway by which fangchinoline plays a role in different human gastric cancer cells lines. We found that fangchinoline effectively suppressed proliferation and invasion of SGC7901 cell lines, but not MKN45 cell lines by inhibiting the expression of PI3K and its downstream pathway. All of the Akt/MMP2/MMP9 pathway, Akt/Bad pathway, and Akt/Gsk3β/CDK2 pathway could be inhibited by fangchinoline through inhibition of PI3K. Taken together, these results suggest that fangchinoline targets PI3K in tumor cells that express PI3K abundantly and inhibits the growth and invasive ability of the tumor cells. PMID:25872479

  5. Fangchinoline targets PI3K and suppresses PI3K/AKT signaling pathway in SGC7901 cells.

    PubMed

    Tian, Feng; Ding, Ding; Li, Dandan

    2015-01-01

    Fangchinoline, an important compound in Stephania tetrandra S. Moore, as a novel antitumor agent, has been implicated in several types of cancers cells except gastric cancer. To investigate whether fangchinoline affects gastric cancer cells, we detected the signaling pathway by which fangchinoline plays a role in different human gastric cancer cells lines. We found that fangchinoline effectively suppressed proliferation and invasion of SGC7901 cell lines, but not MKN45 cell lines by inhibiting the expression of PI3K and its downstream pathway. All of the Akt/MMP2/MMP9 pathway, Akt/Bad pathway, and Akt/Gsk3β/CDK2 pathway could be inhibited by fangchinoline through inhibition of PI3K. Taken together, these results suggest that fangchinoline targets PI3K in tumor cells that express PI3K abundantly and inhibits the growth and invasive ability of the tumor cells. PMID:25872479

  6. The silencing of Pokemon attenuates the proliferation of hepatocellular carcinoma cells in vitro and in vivo by inhibiting the PI3K/Akt pathway.

    PubMed

    Lin, Chan-Chan; Zhou, Jing-Ping; Liu, Yun-Peng; Liu, Jing-Jing; Yang, Xiao-Ning; Jazag, Amarsanaa; Zhang, Zhi-Ping; Guleng, Bayasi; Ren, Jian-Lin

    2012-01-01

    Pokemon (POK erythroid myeloid ontogenic factor), which belongs to the POK protein family, is also called LRF, OCZF and FBI-1. As a transcriptional repressor, Pokemon assumes a critical function in cellular differentiation and oncogenesis. Our study identified an oncogenic role for Pokemon in human hepatocellular carcinoma (HCC). We successfully established human HepG2 and Huh-7 cell lines in which Pokemon was stably knocked down. We demonstrated that Pokemon silencing inhibited cell proliferation and migration. Pokemon knockdown inhibited the PI3K/Akt and c-Raf/MEK/ERK pathways and modulated the expression of various cell cycle regulators in HepG2 and Huh-7 cells. Therefore, Pokemon may also be involved in cell cycle progression in these cells. We confirmed that Pokemon silencing suppresses hepatocellular carcinoma growth in tumor xenograft mice. These results suggest that Pokemon promotes cell proliferation and migration in hepatocellular carcinoma and accelerates tumor development in an Akt- and ERK-signaling-dependent manner. PMID:23300578

  7. ELABELA Is an Endogenous Growth Factor that Sustains hESC Self-Renewal via the PI3K/AKT Pathway.

    PubMed

    Ho, Lena; Tan, Shawn Y X; Wee, Sheena; Wu, Yixuan; Tan, Sam J C; Ramakrishna, Navin B; Chng, Serene C; Nama, Srikanth; Szczerbinska, Iwona; Sczerbinska, Iwona; Chan, Yun-Shen; Avery, Stuart; Tsuneyoshi, Norihiro; Ng, Huck Hui; Gunaratne, Jayantha; Dunn, N Ray; Reversade, Bruno

    2015-10-01

    ELABELA (ELA) is a peptide hormone required for heart development that signals via the Apelin Receptor (APLNR, APJ). ELA is also abundantly secreted by human embryonic stem cells (hESCs), which do not express APLNR. Here we show that ELA signals in a paracrine fashion in hESCs to maintain self-renewal. ELA inhibition by CRISPR/Cas9-mediated deletion, shRNA, or neutralizing antibodies causes reduced hESC growth, cell death, and loss of pluripotency. Global phosphoproteomic and transcriptomic analyses of ELA-pulsed hESCs show that it activates PI3K/AKT/mTORC1 signaling required for cell survival. ELA promotes hESC cell-cycle progression and protein translation and blocks stress-induced apoptosis. INSULIN and ELA have partially overlapping functions in hESC medium, but only ELA can potentiate the TGFβ pathway to prime hESCs toward the endoderm lineage. We propose that ELA, acting through an alternate cell-surface receptor, is an endogenous secreted growth factor in human embryos and hESCs that promotes growth and pluripotency.

  8. scAAV9-VEGF prolongs the survival of transgenic ALS mice by promoting activation of M2 microglia and the PI3K/Akt pathway.

    PubMed

    Wang, Ying; Duan, Weisong; Wang, Wan; Di Wen; Liu, Yaling; Liu, Yakun; Li, Zhongyao; Hu, Haojie; Lin, Huiqian; Cui, Can; Li, Dongxiao; Dong, Hui; Li, Chunyan

    2016-10-01

    Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease that leads to paralysis and death three to five years after diagnosis in most patients. The disease is incurable, and the mechanism of motoneuron degeneration remains unknown, although research has demonstrated that activated microglia are involved in motor neuron death. Here, we used a simple method to deliver AAV9 virus by direct intrathecal injection and found that scAAV9-VEGF-165 improved the motor performance and prolonged the life span of SOD1-G93A mice. Furthermore, scAAV9-VEGF-165 activated the PI3K/Akt survival pathway and increased the level of Bcl-2, which contributed to the protection of motor neurons. Additionally, scAAV9-VEGF-165 attenuated the expression of classically activated (M1) microglial markers and enhanced the expression of alternatively activated (M2) microglial markers. Taken together, the results of our study suggest that simple, direct intrathecal injection of scAAV9-VEGF-165 may have a curative effect for ALS. PMID:27392886

  9. The PI3K/Akt/mTOR pathway is implicated in the premature senescence of primary human endothelial cells exposed to chronic radiation.

    PubMed

    Yentrapalli, Ramesh; Azimzadeh, Omid; Sriharshan, Arundhathi; Malinowsky, Katharina; Merl, Juliane; Wojcik, Andrzej; Harms-Ringdahl, Mats; Atkinson, Michael J; Becker, Karl-Friedrich; Haghdoost, Siamak; Tapio, Soile

    2013-01-01

    The etiology of radiation-induced cardiovascular disease (CVD) after chronic exposure to low doses of ionizing radiation is only marginally understood. We have previously shown that a chronic low-dose rate exposure (4.1 mGy/h) causes human umbilical vein endothelial cells (HUVECs) to prematurely senesce. We now show that a dose rate of 2.4 mGy/h is also able to trigger premature senescence in HUVECs, primarily indicated by a loss of growth potential and the appearance of the senescence-associated markers ß-galactosidase (SA-ß-gal) and p21. In contrast, a lower dose rate of 1.4 mGy/h was not sufficient to inhibit cellular growth or increase SA-ß-gal-staining despite an increased expression of p21. We used reverse phase protein arrays and triplex Isotope Coded Protein Labeling with LC-ESI-MS/MS to study the proteomic changes associated with chronic radiation-induced senescence. Both technologies identified inactivation of the PI3K/Akt/mTOR pathway accompanying premature senescence. In addition, expression of proteins involved in cytoskeletal structure and EIF2 signaling was reduced. Age-related diseases such as CVD have been previously associated with increased endothelial cell senescence. We postulate that a similar endothelial aging may contribute to the increased rate of CVD seen in populations chronically exposed to low-dose-rate radiation.

  10. The PI3K/Akt/mTOR Pathway Is Implicated in the Premature Senescence of Primary Human Endothelial Cells Exposed to Chronic Radiation

    PubMed Central

    Yentrapalli, Ramesh; Azimzadeh, Omid; Sriharshan, Arundhathi; Malinowsky, Katharina; Merl, Juliane; Wojcik, Andrzej; Harms-Ringdahl, Mats; Atkinson, Michael J.; Becker, Karl-Friedrich; Haghdoost, Siamak; Tapio, Soile

    2013-01-01

    The etiology of radiation-induced cardiovascular disease (CVD) after chronic exposure to low doses of ionizing radiation is only marginally understood. We have previously shown that a chronic low-dose rate exposure (4.1 mGy/h) causes human umbilical vein endothelial cells (HUVECs) to prematurely senesce. We now show that a dose rate of 2.4 mGy/h is also able to trigger premature senescence in HUVECs, primarily indicated by a loss of growth potential and the appearance of the senescence-associated markers ß-galactosidase (SA-ß-gal) and p21. In contrast, a lower dose rate of 1.4 mGy/h was not sufficient to inhibit cellular growth or increase SA-ß-gal-staining despite an increased expression of p21. We used reverse phase protein arrays and triplex Isotope Coded Protein Labeling with LC-ESI-MS/MS to study the proteomic changes associated with chronic radiation-induced senescence. Both technologies identified inactivation of the PI3K/Akt/mTOR pathway accompanying premature senescence. In addition, expression of proteins involved in cytoskeletal structure and EIF2 signaling was reduced. Age-related diseases such as CVD have been previously associated with increased endothelial cell senescence. We postulate that a similar endothelial aging may contribute to the increased rate of CVD seen in populations chronically exposed to low-dose-rate radiation. PMID:23936371

  11. Ghrelin promotes intestinal epithelial cell proliferation through PI3K/Akt pathway and EGFR trans-activation both converging to ERK 1/2 phosphorylation.

    PubMed

    Waseem, Talat; Duxbury, Mark; Ashley, Stanley W; Robinson, Malcolm K

    2014-02-01

    Little is known about ghrelin's effects on intestinal epithelial cells even though it is known to be a mitogen for a variety of other cell types. Because ghrelin is released in close proximity to the proliferative compartment of the intestinal tract, we hypothesized that ghrelin may have potent pro-proliferative effect on intestinal epithelial cells as well. To test this hypothesis, we characterized the effects of ghrelin on FHs74Int and Caco-2 intestinal epithelial cell lines in vitro. We found that ghrelin has potent dose dependent proliferative effects in both cell lines through a yet to be characterized G protein coupled growth hormone secretagogue receptor (GHS-R) subtype. Consistent with above findings, cell cycle flowcytometric analyses demonstrated that ghrelin shifts cells from the G1 to S phase and thereby promotes cell cycle progression. Further characterization of subcellular events, suggested that ghrelin mediates its pro-proliferative effect through Adenylate cyclase (AC)-independent epidermal growth factor receptor (EGFR) trans-activation and PI3K-Akt phosphorylation. Both these pathways converge to stimulate MAPK, ERK 1/2 downstream. The role of ghrelin in states where intestinal mucosal injury and rapid mucosal repair occur warrants further investigation.

  12. Xyloketal B suppresses glioblastoma cell proliferation and migration in vitro through inhibiting TRPM7-regulated PI3K/Akt and MEK/ERK signaling pathways.

    PubMed

    Chen, Wen-Liang; Turlova, Ekaterina; Sun, Christopher L F; Kim, Ji-Sun; Huang, Sammen; Zhong, Xiao; Guan, Yong-Yuan; Wang, Guan-Lei; Rutka, James T; Feng, Zhong-Ping; Sun, Hong-Shuo

    2015-04-01

    Glioblastoma, the most common and aggressive type of brain tumors, has devastatingly proliferative and invasive characteristics. The need for finding a novel and specific drug target is urgent as the current approaches have limited therapeutic effects in treating glioblastoma. Xyloketal B is a marine compound obtained from mangrove fungus Xylaria sp. (No. 2508) from the South China Sea, and has displayed antioxidant activity and protective effects on endothelial and neuronal oxidative injuries. In this study, we used a glioblastoma U251 cell line to (1) explore the effects of xyloketal B on cell viability, proliferation, and migration; and (2) investigate the underlying molecular mechanisms and signaling pathways. MTT assay, colony formation, wound healing, western blot, and patch clamp techniques were employed. We found that xyloketal B reduced cell viability, proliferation, and migration of U251 cells. In addition, xyloketal B decreased p-Akt and p-ERK1/2 protein expressions. Furthermore, xyloketal B blocked TRPM7 currents in HEK-293 cells overexpressing TRPM7. These effects were confirmed by using a TRPM7 inhibitor, carvacrol, in a parallel experiment. Our findings indicate that TRPM7-regulated PI3K/Akt and MEK/ERK signaling is involved in anti-proliferation and migration effects of xyloketal B on U251 cells, providing in vitro evidence for the marine compound xyloketal B to be a potential drug for treating glioblastoma. PMID:25913706

  13. Paeonol and danshensu combination attenuates apoptosis in myocardial infarcted rats by inhibiting oxidative stress: Roles of Nrf2/HO-1 and PI3K/Akt pathway

    PubMed Central

    Li, Hua; Song, Fan; Duan, Lin-Rui; Sheng, Juan-Juan; Xie, Yan-Hua; Yang, Qian; Chen, Ying; Dong, Qian-Qian; Zhang, Bang-Le; Wang, Si-Wang

    2016-01-01

    Paeonol and danshensu is the representative active ingredient of traditional Chinese medicinal herbs Cortex Moutan and Radix Salviae Milthiorrhizae, respectively. Paeonol and danshensu combination (PDSS) has putative cardioprotective effects in treating ischemic heart disease (IHD). However, the evidence for the protective effect is scarce and the pharmacological mechanisms of the combination remain unclear. The present study was designed to investigate the protective effect of PDSS on isoproterenol (ISO)-induced myocardial infarction in rats and to elucidate the potential mechanism. Assays of creatine kinase-MB, cardiac troponin I and T and histopathological analysis revealed PDSS significantly prevented myocardial injury induced by ISO. The ISO-induced profound elevation of oxidative stress was also suppressed by PDSS. TUNEL and caspase-3 activity assay showed that PDSS significantly inhibited apoptosis in myocardia. In exploring the underlying mechanisms of PDSS, we found PDSS enhanced the nuclear translocation of Nrf2 in myocardial injured rats. Furthermore, PDSS increased phosphorylated PI3K and Akt, which may in turn activate antioxidative and antiapoptotic signaling events in rat. These present findings demonstrated that PDSS exerts significant cardioprotective effects against ISO-induced myocardial infarction in rats. The protective effect is, at least partly, via activation of Nrf2/HO-1 signaling and involvement of the PI3K/Akt cell survival signaling pathway. PMID:27021411

  14. Nobiletin attenuates metastasis via both ERK and PI3K/Akt pathways in HGF-treated liver cancer HepG2 cells.

    PubMed

    Shi, Ming-Der; Liao, Yi-Chen; Shih, Yuan-Wei; Tsai, Li-Yu

    2013-06-15

    Hepatocyte growth factor (HGF), and its receptor, c-Met activation has recently been shown to play important roles in cancer invasion and metastasis in a wide variety of tumor cells. We use HGF as an invasive inducer of human HepG2 cells to investigate the effect of four flavones including apigenin, tricetin, tangeretin, and nobiletin on HGF/c-Met-mediated tumor invasion and metastasis. Among them, nobiletin markedly inhibited HGF-induced the abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay and transwell-chamber invasion/migration assay under non-cytotoxic concentrations. Data also showed nobiletin inhibited HGF-induced cell scattering and cytoskeleton changed such as filopodia and lamellipodia. Furthermore, nobiletin could inhibit HGF-induced the membrane localization of phosphorylated c-Met, ERK2, and Akt, but not phosphorylated JNK1/2 and p38. Next, nobiletin significantly decreased the levels of phospho-ERK2 and phospho-Akt in ERK2 or Akt siRNA-transfected cells concomitantly with a marked reduction on cell invasion and migration. In conclusion, nobiletin attenuates HGF-induced HepG2 cells metastasis involving both ERK and PI3K/Akt pathways and are potentially useful as anti-metastatic agents for the treatment of hepatoma.

  15. Colocalized delivery of rapamycin and paclitaxel to tumors enhances synergistic targeting of the PI3K/Akt/mTOR pathway.

    PubMed

    Blanco, Elvin; Sangai, Takafumi; Wu, Suhong; Hsiao, Angela; Ruiz-Esparza, Guillermo U; Gonzalez-Delgado, Carlos A; Cara, Francisca E; Granados-Principal, Sergio; Evans, Kurt W; Akcakanat, Argun; Wang, Ying; Do, Kim-Anh; Meric-Bernstam, Funda; Ferrari, Mauro

    2014-07-01

    Ongoing clinical trials target the aberrant PI3K/Akt/mammalian target of rapamycin (mTOR) pathway in breast cancer through administration of rapamycin, an allosteric mTOR inhibitor, in combination with paclitaxel. However, synergy may not be fully exploited clinically because of distinct pharmacokinetic parameters of drugs. This study explores the synergistic potential of site-specific, colocalized delivery of rapamycin and paclitaxel through nanoparticle incorporation. Nanoparticle drug loading was accurately controlled, and synergistic drug ratios established in vitro. Precise drug ratios were maintained in tumors 48 hours after nanoparticle administration to mice, at levels twofold greater than liver and spleen, yielding superior antitumor activity compared to controls. Simultaneous and preferential in vivo delivery of rapamycin and paclitaxel to tumors yielded mechanistic insights into synergy involving suppression of feedback loop Akt phosphorylation and its downstream targets. Findings demonstrate that a same time, same place, and specific amount approach to combination chemotherapy by means of nanoparticle delivery has the potential to successfully translate in vitro synergistic findings in vivo. Predictive in vitro models can be used to determine optimum drug ratios for antitumor efficacy, while nanoparticle delivery of combination chemotherapies in preclinical animal models may lead to enhanced understanding of mechanisms of synergy, ultimately opening several avenues for personalized therapy.

  16. Anticancer Effects of Paris Saponins by Apoptosis and PI3K/AKT Pathway in Gefitinib-Resistant Non-Small Cell Lung Cancer

    PubMed Central

    Zhu, Xinhai; Jiang, Hao; Li, Jinhui; Xu, Ji; Fei, Zhenghua

    2016-01-01

    Background Paris saponins have been studied for their anticancer effects in various cancer types, but the mechanisms underlying the cytotoxic effects, especially in EGFR-TKI-resistant cells, are still unclear. We explored the potential mechanism of the antitumor effects of PSI, II, VI, VII in EGFR-TKI-resistant cells and attempted to develop PSI, II, VI, VII as a systemic treatment strategy for EGFR-TKI-resistant lung cancer. Material/Methods Growth inhibition was detected by MTT assay. The apoptosis assay was detected using annexin-V/PI and Hoechst staining. The level of PI3K, pAKT, Bax, Bcl-2, caspase-3, and caspase-9 protein expression were detected using Western blot analysis. Results The results revealed that PSI, II, VI, VII inhibited the proliferation of PC-9-ZD cells. Furthermore, PSI, II, VI, VII induced significant cell apoptosis. The levels of PI3K, pAKT, Bcl-2 protein decreased, while the Bax, caspase-3, and caspase-9 protein was increased by PSI, II, PSVI, PSVII treatment and resulted in increased sensitivity to gefitinib in PC-9-ZD cells. Conclusions The underlying mechanism of Paris saponins may be related to targeting the PI3K/AKT pathways to cause apoptosis. Our results suggest a therapeutic potential of Paris saponins in clinical settings for gefitinib-resistant NSCLC. PMID:27125283

  17. Anticancer Effects of Paris Saponins by Apoptosis and PI3K/AKT Pathway in Gefitinib-Resistant Non-Small Cell Lung Cancer.

    PubMed

    Zhu, XinHai; Jiang, Hao; Li, Jinhui; Xu, Ji; Fei, Zhenghua

    2016-01-01

    BACKGROUND Paris saponins have been studied for their anticancer effects in various cancer types, but the mechanisms underlying the cytotoxic effects, especially in EGFR-TKI-resistant cells, are still unclear. We explored the potential mechanism of the antitumor effects of PSI, II, VI, VII in EGFR-TKI-resistant cells and attempted to develop PSI, II, VI, VII as a systemic treatment strategy for EGFR-TKI-resistant lung cancer. MATERIAL AND METHODS Growth inhibition was detected by MTT assay. The apoptosis assay was detected using annexin-V/PI and Hoechst staining. The level of PI3K, pAKT, Bax, Bcl-2, caspase-3, and caspase-9 protein expression were detected using Western blot analysis. RESULTS The results revealed that PSI, II, VI, VII inhibited the proliferation of PC-9-ZD cells. Furthermore, PSI, II, VI, VII induced significant cell apoptosis. The levels of PI3K, pAKT, Bcl-2 protein decreased, while the Bax, caspase-3, and caspase-9 protein was increased by PSI, II, PSVI, PSVII treatment and resulted in increased sensitivity to gefitinib in PC-9-ZD cells. CONCLUSIONS The underlying mechanism of Paris saponins may be related to targeting the PI3K/AKT pathways to cause apoptosis. Our results suggest a therapeutic potential of Paris saponins in clinical settings for gefitinib-resistant NSCLC. PMID:27125283

  18. Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

    PubMed Central

    Kuo, Han-Peng; Hsu, Shih-Chung; Li, Jhy-Wei; Tseng, Hsiu-Hsueh; Chuang, Tzu-Chao; Liu, Jah-Yao; Chen, Shih-Jung; Su, Muh-Hwan; Cheng, Yung-Chi; Chou, Wei-Yuan; Kao, Ming-Ching

    2013-01-01

    Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT), one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE) inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin) in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2. PMID:23662119

  19. Xyloketal B Suppresses Glioblastoma Cell Proliferation and Migration in Vitro through Inhibiting TRPM7-Regulated PI3K/Akt and MEK/ERK Signaling Pathways

    PubMed Central

    Chen, Wen-Liang; Turlova, Ekaterina; Sun, Christopher L. F.; Kim, Ji-Sun; Huang, Sammen; Zhong, Xiao; Guan, Yong-Yuan; Wang, Guan-Lei; Rutka, James T.; Feng, Zhong-Ping; Sun, Hong-Shuo

    2015-01-01

    Glioblastoma, the most common and aggressive type of brain tumors, has devastatingly proliferative and invasive characteristics. The need for finding a novel and specific drug target is urgent as the current approaches have limited therapeutic effects in treating glioblastoma. Xyloketal B is a marine compound obtained from mangrove fungus Xylaria sp. (No. 2508) from the South China Sea, and has displayed antioxidant activity and protective effects on endothelial and neuronal oxidative injuries. In this study, we used a glioblastoma U251 cell line to (1) explore the effects of xyloketal B on cell viability, proliferation, and migration; and (2) investigate the underlying molecular mechanisms and signaling pathways. MTT assay, colony formation, wound healing, western blot, and patch clamp techniques were employed. We found that xyloketal B reduced cell viability, proliferation, and migration of U251 cells. In addition, xyloketal B decreased p-Akt and p-ERK1/2 protein expressions. Furthermore, xyloketal B blocked TRPM7 currents in HEK-293 cells overexpressing TRPM7. These effects were confirmed by using a TRPM7 inhibitor, carvacrol, in a parallel experiment. Our findings indicate that TRPM7-regulated PI3K/Akt and MEK/ERK signaling is involved in anti-proliferation and migration effects of xyloketal B on U251 cells, providing in vitro evidence for the marine compound xyloketal B to be a potential drug for treating glioblastoma. PMID:25913706

  20. The silencing of Pokemon attenuates the proliferation of hepatocellular carcinoma cells in vitro and in vivo by inhibiting the PI3K/Akt pathway.

    PubMed

    Lin, Chan-Chan; Zhou, Jing-Ping; Liu, Yun-Peng; Liu, Jing-Jing; Yang, Xiao-Ning; Jazag, Amarsanaa; Zhang, Zhi-Ping; Guleng, Bayasi; Ren, Jian-Lin

    2012-01-01

    Pokemon (POK erythroid myeloid ontogenic factor), which belongs to the POK protein family, is also called LRF, OCZF and FBI-1. As a transcriptional repressor, Pokemon assumes a critical function in cellular differentiation and oncogenesis. Our study identified an oncogenic role for Pokemon in human hepatocellular carcinoma (HCC). We successfully established human HepG2 and Huh-7 cell lines in which Pokemon was stably knocked down. We demonstrated that Pokemon silencing inhibited cell proliferation and migration. Pokemon knockdown inhibited the PI3K/Akt and c-Raf/MEK/ERK pathways and modulated the expression of various cell cycle regulators in HepG2 and Huh-7 cells. Therefore, Pokemon may also be involved in cell cycle progression in these cells. We confirmed that Pokemon silencing suppresses hepatocellular carcinoma growth in tumor xenograft mice. These results suggest that Pokemon promotes cell proliferation and migration in hepatocellular carcinoma and accelerates tumor development in an Akt- and ERK-signaling-dependent manner.

  1. Mild caloric restriction reduces blood pressure and activates endothelial AMPK-PI3K-Akt-eNOS pathway in obese Zucker rats.

    PubMed

    García-Prieto, C F; Pulido-Olmo, H; Ruiz-Hurtado, G; Gil-Ortega, M; Aranguez, I; Rubio, M A; Ruiz-Gayo, M; Somoza, B; Fernández-Alfonso, M S

    2015-01-01

    Genetic obesity models exhibit endothelial dysfunction associated to adenosine monophosphate-activated protein kinase (AMPK) dysregulation. This study aims to assess if mild short-term caloric restriction (CR) restores endothelial AMPK activity leading to an improvement in endothelial function. Twelve-week old Zucker lean and obese (fa/fa) male rats had access to standard chow either ad libitum (AL, n=8) or 80% of AL (CR, n=8) for two weeks. Systolic blood pressure was significantly higher in fa/fa AL rats versus lean AL animals, but was normalized by CR. Endothelium-dependent relaxation to acetylcholine (ACh, 10(-9) to 10(-4) M) was reduced in fa/fa AL compared to control lean AL rats (p<0.001), and restored by CR. The AMPK activator AICAR (10(-5) to 8·10(-3) M) elicited a lower relaxation in fa/fa AL rings that was normalized by CR (p<0.001). Inhibition of PI3K (wortmannin, 10(-7) M), Akt (triciribine, 10(-5) M), or eNOS (L-NAME, 10(-4) M) markedly reduced AICAR-induced relaxation in lean AL, but not in fa/fa AL rats. These inhibitions were restored by CR in Zucker fa/fa rings. These data show that mild short-term CR improves endothelial function and lowers blood pressure in obesity due to the activation of the AMPK-PI3K-Akt-eNOS pathway. PMID:25530153

  2. Gelsolin-mediated activation of PI3K/Akt pathway is crucial for hepatocyte growth factor-induced cell scattering in gastric carcinoma

    PubMed Central

    Huang, Baohua; Deng, Shuo; Loo, Ser Yue; Datta, Arpita; Yap, Yan Lin; Yan, Benedict; Ooi, Chia Huey; Dinh, Thuy Duong; Zhuo, Jingli; Tochhawng, Lalchhandami; Gopinadhan, Suma; Jegadeesan, Tamilarasi; Tan, Patrick; Salto-Tellez, Manuel; Yong, Wei Peng; Soong, Richie; Yeoh, Khay Guan; Goh, Yaw Chong; Lobie, Peter E.; Yang, Henry; Kumar, Alan Prem; Maciver, Sutherland K.; So, Jimmy B.Y.; Yap, Celestial T.

    2016-01-01

    In gastric cancer (GC), the main subtypes (diffuse and intestinal types) differ in pathological characteristics, with diffuse GC exhibiting early disseminative and invasive behaviour. A distinctive feature of diffuse GC is loss of intercellular adhesion. Although widely attributed to mutations in the CDH1 gene encoding E-cadherin, a significant percentage of diffuse GC do not harbor CDH1 mutations. We found that the expression of the actin-modulating cytoskeletal protein, gelsolin, is significantly higher in diffuse-type compared to intestinal-type GCs, using immunohistochemical and microarray analysis. Furthermore, in GCs with wild-type CDH1, gelsolin expression correlated inversely with CDH1 gene expression. Downregulating gelsolin using siRNA in GC cells enhanced intercellular adhesion and E-cadherin expression, and reduced invasive capacity. Interestingly, hepatocyte growth factor (HGF) induced increased gelsolin expression, and gelsolin was essential for HGF-medicated cell scattering and E-cadherin transcriptional repression through Snail, Twist and Zeb2. The HGF-dependent effect on E-cadherin was found to be mediated by interactions between gelsolin and PI3K-Akt signaling. This study reveals for the first time a function of gelsolin in the HGF/cMet oncogenic pathway, which leads to E-cadherin repression and cell scattering in gastric cancer. Our study highlights gelsolin as an important pro-disseminative factor contributing to the aggressive phenotype of diffuse GC. PMID:27058427

  3. CCL5 promotes VEGF-dependent angiogenesis by down-regulating miR-200b through PI3K/Akt signaling pathway in human chondrosarcoma cells

    PubMed Central

    Liu, Guan-Ting; Chen, Hsien-Te; Tsou, Hsi-Kai; Tan, Tzu-Wei; Fong, Yi-Chin; Chen, Po-Chen; Yang, Wei-Hung; Wang, Shih-Wei; Chen, Jui-Chieh; Tang, Chih-Hsin

    2014-01-01

    Chondrosarcoma is the second most common primary malignant bone cancer, with potential for local invasion and distant metastasis. Chemokine CCL5 (formerly RANTES) of the CC-chemokine family plays a crucial role in metastasis. Angiogenesis is essential for the cancer metastasis. However, correlation of CCL5 with vascular endothelial growth factor (VEGF) expression and angiogenesis in human chondrosarcoma is still unknown. CCL5-mediated VEGF expression was assessed by qPCR, ELISA, and Western blotting. CCL5-induced angiogenesis was examined by migration and tube formation in endothelial progenitor cells in vitro. CCL5 increased VEGF expression and also promoted chondrosarcoma conditional medium-mediated angiogenesis in vitro and in vivo. Stimulation of chondrosarcoma with CCL5 augmented PI3K and Akt phosphorylation, while PI3K and Akt inhibitor or siRNA abolished CCL5-induced VEGF expression and angiogenesis. We also demonstrated CCL5 inhibiting miR-200b expression and miR-200b mimic reversing the CCL5-enhanced VEGF expression and angiogenesis. Moreover, in chondrosarcoma patients showed the positive correlation between CCL5 and VEGF; negative correlation between CCL5 and miR-200b. Taken together, results demonstrate CCL5 promoting VEGF-dependent angiogenesis in human chondrosarcoma cells by down-regulating miR-200b through PI3K/Akt signaling pathway. PMID:25301739

  4. Salvianolic Acid B Prevents Iodinated Contrast Media-Induced Acute Renal Injury in Rats via the PI3K/Akt/Nrf2 Pathway

    PubMed Central

    Tongqiang, Liu; Shaopeng, Liu; Xiaofang, Yu; Nana, Song; Xialian, Xu; Jiachang, Hu; Ting, Zhang; Xiaoqiang, Ding

    2016-01-01

    Contrast-induced acute renal injury (CI-AKI) has become a common cause of hospital-acquired renal failure. However, the development of prophylaxis strategies and approved therapies for CI-AKI is limited. Salvianolic acid B (SB) can treat cardiovascular-related diseases. The aim of the present study was to assess the effect of SB on prevention of CI-AKI and explore its underlying mechanisms. We examined its effectiveness of preventing renal injury in a novel CI-AKI rat model. Compared with saline, intravenous SB pretreatment significantly attenuated elevations in serum creatinine and the histological changes of renal tubular injuries, reduced the number of apoptosis-positive tubular cells, activated Nrf2, and lowered the levels of renal oxidative stress induced by iodinated contrast media. The above renoprotection of SB was abolished by the PI3K inhibitor (wortmannin). In HK-2 cells, SB activated Nrf2 and decreased the levels of oxidative stress induced by hydrogen peroxide and subsequently improved cell viability. The above cytoprotection of SB was blocked by the PI3K inhibitor (wortmannin) or siNrf2. Thus, our results demonstrate that, due to its antioxidant properties, SB has the potential to effectively prevent CI-AKI via the PI3K/Akt/Nrf2 pathway. PMID:27382429

  5. Guizhi Fuling Wan, a Traditional Chinese Herbal Formula, Sensitizes Cisplatin-Resistant Human Ovarian Cancer Cells through Inactivation of the PI3K/AKT/mTOR Pathway

    PubMed Central

    Guo, Xiaojuan; Bian, Hua; Yang, Lei; Chen, Zhong; Zang, Wenhua; Yang, Jingke

    2016-01-01

    The aim of the study was to explore the possible mechanisms that Guizhi Fuling Wan (GFW) enhances the sensitivity of the SKOV3/DDP ovarian cancer cells and the resistant xenograft tumours to cisplatin. Rat medicated sera containing GFW were prepared by administering GFW to rats, and the primary bioactive constituents of the sera were gallic acid, paeonol, and paeoniflorin analysed by HPLC/QqQ MS. Cell counting kit-8 analysis was shown that coincubation of the sera with cisplatin/paclitaxel enhanced significantly the cytotoxic effect of cisplatin or paclitaxel in SKOV3/DDP cells. The presence of the rat medicated sera containing GFW resulted in an increase in rhodamine 123 accumulation by flow cytometric assays and a decrease in the protein levels of P-gp, phosphorylation of AKT at Ser473, and mTOR in a dose-dependent manner in SKOV3/DDP cells by western blot analysis, but the sera had no effect on the protein levels of PI3K p110α and total AKT. The low dose of GFW enhanced the anticancer efficacy of cisplatin and paclitaxel treatment in resistant SKOV3/DDP xenograft tumours. GFW could sensitize cisplatin-resistant SKOV3/DDP cells by inhibiting the protein level and function of P-gp, which may be medicated through inactivation of the PI3K/AKT/mTOR pathway. PMID:27293459

  6. Efficient Conversion of Spermatogonial Stem Cells to Phenotypic and Functional Dopaminergic Neurons via the PI3K/Akt and P21/Smurf2/Nolz1 Pathway.

    PubMed

    Yang, Hao; Liu, Yang; Hai, Yanan; Guo, Ying; Yang, Shi; Li, Zheng; Gao, Wei-Qiang; He, Zuping

    2015-12-01

    Parkinson's disease (PD) is a common neurodegenerative syndrome characterized by loss of midbrain dopaminergic (DA) neurons. Generation of functional dopaminergic (DA) neurons is of unusual significance for treating Parkinson's disease (PD). However, direct conversion of spermatogonial stem cells (SSCs) to functional DA neurons without being reprogrammed to a pluripotent status has not been achieved. Here, we report an efficient approach to obtain morphological, phenotypic, and functional DA neurons from SSCs using a specific combination of olfactory ensheathing cell-conditioned medium (OECCM) and several defined growth factors (DGF). By following the current protocol, direct conversion of SSCs (both SSC line and primary SSCs) to neural cells and DA neurons was demonstrated by expression of numerous phenotypic genes and proteins for neural cells, as well as cell morphological features. More significantly, SSCs-derived DA neurons acquired neuronal functional properties such as synapse formation, electrophysiology activity, and dopamine secretion. Furthermore, PI3K/Akt pathway and p21/Nolz1 cascades were activated whereas Smurf2 was inactivated, leading to cell cycle exit during the conversion of SSCs into DA neurons. Collectively, this study could provide sufficient neural cells from SSCs for applications in the treatment of PD and offers novel insights into mechanisms underlying neural system development from the line of germ cells.

  7. MicroRNA-7 inhibits the stemness of prostate cancer stem-like cells and tumorigenesis by repressing KLF4/PI3K/Akt/p21 pathway.

    PubMed

    Chang, Yun-Li; Zhou, Pei-Jie; Wei, Lianzi; Li, Wang; Ji, Zhongzhong; Fang, Yu-Xiang; Gao, Wei-Qiang

    2015-09-15

    Up to now, the molecular mechanisms underlying the stemness of prostate cancer stem cells (PCSCs) are still poorly understood. In this study, we demonstrated that microRNA-7 (miR-7) appears to be a novel tumor-suppressor miRNA, which abrogates the stemness of PCSCs and inhibits prostate tumorigenesis by suppressing a key stemness factor KLF4. MicroRNA-7 is down-regulated in prostate cancer cells compared to non-tumorigenic prostate epithelial cells. Restoration of miR-7 suppresses the expression of the stemness factor KLF4 in PCSCs and inhibits prostate tumorigenesis both in vitro and in vivo. Interestingly, the suppression of the stemness of PCSCs by miR-7 is sustained for generations in xenografts. Analysis of clinical samples also revealed a negative correlation between miR-7 expression and prostate tumor progression. Mechanistically, overexpression of miR-7 may lead to a cell cycle arrest but not apoptosis, which seems achieved via suppressing the KLF4/PI3K/Akt/p21 pathway. This study identifies miR-7 as a suppressor of PCSCs' stemness and implicates its potential application for PCa therapy.

  8. The Apoptotic Effect of Ursolic Acid on SK-Hep-1 Cells is Regulated by the PI3K/Akt, p38 and JNK MAPK Signaling Pathways.

    PubMed

    Chuang, Wan-Ling; Lin, Ping-Yi; Lin, Hui-Chuan; Chen, Yao-Li

    2016-01-01

    Ursolic acid (UA) is a pentacyclic triterpene acid that is present in a wide variety of medicinal herbs and edible plants. This study investigated the effect of UA on apoptosis and proliferation of hepatocellular carcinoma SK-Hep-1 cells. After treatment of SK-Hep-1 cells with different concentrations of UA, we observed that cell viability was reduced in a dose- and time-dependent manner. Furthermore, there was a dose-dependent increase in the percentage of cells in the sub-G1 and G2/M phases, with cells treated with 60 μM showing the highest percentages of cells in those phases. UA-induced chromatin condensation of nuclei was observed by using DAPI staining. The western blot results revealed that exposure to UA was associated with decreased expression of the anti-apoptotic proteins Mcl-1, Bcl-xL, Bcl-2, and TCTP and increased expression of apoptosis-related proteins TNF-α, Fas, FADD, Bax, cleaved caspase-3, caspase-8, caspase-9, and PARP. Immunocytochemistry staining showed that treatment with UA resulted in increased expression of caspase-3. Moreover, exposure to UA resulted in the inhibition of the PI3K/Akt and p38 MAPK signaling pathways. These findings suggest that UA inhibits the proliferation of SK-Hep-1 cells and induces apoptosis.

  9. Resveratrol induces cell cycle arrest in human gastric cancer MGC803 cells via the PTEN-regulated PI3K/Akt signaling pathway.

    PubMed

    Jing, Xiaoping; Cheng, Weiwei; Wang, Shiying; Li, Pin; He, Li

    2016-01-01

    Resveratrol is a polyphenolic compound that is extracted from Polygonum cuspidatum and is used in traditional Chinese medicine. Previous data have shown that resveratrol inhibits the growth of human gastric cancer. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and trypan blue assays showed that resveratrol significantly decreased the survival rate of MGC803 cells in a concentration- and time-dependent manner. Our flow cytometric analysis showed that resveratrol treatment arrested the cells at the G0/G1 phase of the cell cycle. Furthermore, western blotting demonstrated that resveratrol decreased the protein expression of phospho-glycogen synthase kinase 3β (p-GSK3β), cyclin D1, phospho-phosphatase and tensin homologue (p-PTEN), phospho-phosphatidylinositol 3'-OH kinase (p-PI3K), and phospho-protein kinase B (p-PKB/Akt). We also found that resveratrol inhibited the progression of the cell cycle in MGC803 cells by repressing p-PI3K and p-Akt expression. Meanwhile, resveratrol did not decrease the phosphorylation level of Akt when the PTEN gene expression was knocked down by an siRNA in the MGC803 cells. Taken together, these results suggest that resveratrol induced cell cycle arrest in human gastric cancer MGC803 cells by regulating the PTEN/PI3K/Akt signaling pathway.

  10. Overexpression of osteopontin induces angiogenesis of endothelial progenitor cells via the avβ3/PI3K/AKT/eNOS/NO signaling pathway in glioma cells.

    PubMed

    Wang, Yingyi; Yan, Wei; Lu, Xiaoming; Qian, Chunfa; Zhang, Junxia; Li, Ping; Shi, Lei; Zhao, Peng; Fu, Zhen; Pu, Peiyu; Kang, Chunshen; Jiang, Tao; Liu, Ning; You, Yongping

    2011-08-01

    Angiogenesis, a hallmark of tumor growth, is regulated by various angiogenic factors. Recent studies have shown that osteopontin (OPN) is a secreted, integrin-binding protein that contributes to glioma progression. However, its effect on the angiogenesis of gliomas is not fully understood. To elucidate the role of OPN in the process of glioma angiogenesis, endothelial progenitor cells (EPCs) were treated with conditioned media of human glioma SHG44 cells overexpressing OPN. Here, we identified that OPN secreted by glioma cells accelerated EPCs angiogenesis in vitro, including proliferation, migration, and tube formation. OPN also induced the activation of AKT and endothelial nitric oxide synthase (eNOS) and increased NO production without affecting the expression of VEGF, VEGFR-1, or VEGFR-2. Moreover, the avβ3 antibody, the PI3-K inhibitor LY294002 and the eNOS inhibitor NMA suppressed the OPN-mediated increase in NO production and angiogenesis in EPCs. Taken together, these results demonstrate that OPN directly stimulates angiogenesis via the avβ3/PI3-K/AKT/eNOS/NO signaling pathway and may play an important role in tumorigenesis by enhancing angiogenesis in gliomas.

  11. Resveratrol induces cell cycle arrest in human gastric cancer MGC803 cells via the PTEN-regulated PI3K/Akt signaling pathway.

    PubMed

    Jing, Xiaoping; Cheng, Weiwei; Wang, Shiying; Li, Pin; He, Li

    2016-01-01

    Resveratrol is a polyphenolic compound that is extracted from Polygonum cuspidatum and is used in traditional Chinese medicine. Previous data have shown that resveratrol inhibits the growth of human gastric cancer. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and trypan blue assays showed that resveratrol significantly decreased the survival rate of MGC803 cells in a concentration- and time-dependent manner. Our flow cytometric analysis showed that resveratrol treatment arrested the cells at the G0/G1 phase of the cell cycle. Furthermore, western blotting demonstrated that resveratrol decreased the protein expression of phospho-glycogen synthase kinase 3β (p-GSK3β), cyclin D1, phospho-phosphatase and tensin homologue (p-PTEN), phospho-phosphatidylinositol 3'-OH kinase (p-PI3K), and phospho-protein kinase B (p-PKB/Akt). We also found that resveratrol inhibited the progression of the cell cycle in MGC803 cells by repressing p-PI3K and p-Akt expression. Meanwhile, resveratrol did not decrease the phosphorylation level of Akt when the PTEN gene expression was knocked down by an siRNA in the MGC803 cells. Taken together, these results suggest that resveratrol induced cell cycle arrest in human gastric cancer MGC803 cells by regulating the PTEN/PI3K/Akt signaling pathway. PMID:26530632

  12. Colocalized Delivery of Rapamycin and Paclitaxel to Tumors Enhances Synergistic Targeting of the PI3K/Akt/mTOR Pathway

    PubMed Central

    Blanco, Elvin; Sangai, Takafumi; Wu, Suhong; Hsiao, Angela; Ruiz-Esparza, Guillermo U; Gonzalez-Delgado, Carlos A; Cara, Francisca E; Granados-Principal, Sergio; Evans, Kurt W; Akcakanat, Argun; Wang, Ying; Do, Kim-Anh; Meric-Bernstam, Funda; Ferrari, Mauro

    2014-01-01

    Ongoing clinical trials target the aberrant PI3K/Akt/mammalian target of rapamycin (mTOR) pathway in breast cancer through administration of rapamycin, an allosteric mTOR inhibitor, in combination with paclitaxel. However, synergy may not be fully exploited clinically because of distinct pharmacokinetic parameters of drugs. This study explores the synergistic potential of site-specific, colocalized delivery of rapamycin and paclitaxel through nanoparticle incorporation. Nanoparticle drug loading was accurately controlled, and synergistic drug ratios established in vitro. Precise drug ratios were maintained in tumors 48 hours after nanoparticle administration to mice, at levels twofold greater than liver and spleen, yielding superior antitumor activity compared to controls. Simultaneous and preferential in vivo delivery of rapamycin and paclitaxel to tumors yielded mechanistic insights into synergy involving suppression of feedback loop Akt phosphorylation and its downstream targets. Findings demonstrate that a same time, same place, and specific amount approach to combination chemotherapy by means of nanoparticle delivery has the potential to successfully translate in vitro synergistic findings in vivo. Predictive in vitro models can be used to determine optimum drug ratios for antitumor efficacy, while nanoparticle delivery of combination chemotherapies in preclinical animal models may lead to enhanced understanding of mechanisms of synergy, ultimately opening several avenues for personalized therapy. PMID:24569835

  13. Suppressive effect of exogenous carbon monoxide on endotoxin-stimulated platelet over-activation via the glycoprotein-mediated PI3K-Akt-GSK3β pathway

    PubMed Central

    Liu, Dadong; Wang, Xu; Qin, Weiting; Chen, Jingjia; Wang, Yawei; Zhuang, Mingfeng; Sun, Bingwei

    2016-01-01

    Platelet activation is an important event involved in the pathophysiological processes of the coagulation system. Clinical evidence has shown that platelets undergo distinctive pathological processes during sepsis. Unfortunately, how platelets physiologically respond to inflammation or sepsis is not well understood. In this study, we used a lipopolysaccharide (LPS)-stimulated platelet model to systemically investigate alterations in membrane glycoprotein expression, molecular signaling, morphology and critical functions of platelets. We found that platelet adhesion, aggregation, secretion, and spreading on immobilized fibrinogen and the expression of platelet membrane glycoproteins were significantly increased by LPS stimulation, and these changes were accompanied by a significant decrease in cGMP levels and an abnormal distribution of platelet α-granules. Exogenous CO reversed these alterations. Profound morphological changes in LPS-stimulated platelets were observed using atomic force microscopy and phase microscopy. Furthermore, the elevated activities of PI3Ks, AKt and GSK-3β were effectively suppressed by exogenous CO, leading to the improvement of platelet function. Together, these results provide evidence that platelet over-activation persists under LPS-stimulation and that exogenous CO plays an important role in suppressing platelet activation via the glycoprotein-mediated PI3K-Akt-GSK3β pathway. PMID:27020460

  14. Dehydroepiandrosterone ameliorates H2O2-induced Leydig cells oxidation damage and apoptosis through inhibition of ROS production and activation of PI3K/Akt pathways.

    PubMed

    Ding, Xiao; Wang, Dian; Li, Longlong; Ma, Haitian

    2016-01-01

    Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement, and administration of DHEA produces a number of beneficial effects in the elderly. Many researchers have suggested that DHEA exerts it function after conversion into more biologically active hormones in peripheral target cells. The actions of DHEA in Leydig cells, a major target cell of DHEA biotransformation in males, are not clear. The present study found that DHEA increased cell viability and decreased reactive oxygen species (ROS) and malondialdehyde contents in H2O2-induced Leydig cells. DHEA significantly increased the activities of superoxide dismutase, catalase and peroxidase, and decreased the DNA damage in H2O2-induced Leydig cells. Apoptosis was significant decreased in H2O2-induced Leydig cells after DHEA treatment. DHEA inhibited the loss of mitochondrial membrane potential (ΔΨm) and the upregulation of the caspase-3 protein level induced by H2O2 in Leydig cells. DHEA also reversed the decrease in PI3K and p-Akt protein levels induced by H2O2. These data showed that DHEA could ameliorate H2O2-induced oxidative damage by increasing anti-oxidative enzyme activities, which resulted in reduced ROS content, and decreased apoptosis, mainly by preventing the loss of ΔΨm and inhibiting caspase-3 protein levels via activation of PI3K/Akt signaling pathways. These results increase our understanding of the molecular mechanism of the anti-ageing effect of DHEA.

  15. Small ribosomal protein subunit S7 suppresses ovarian tumorigenesis through regulation of the PI3K/AKT and MAPK pathways.

    PubMed

    Wang, Ziliang; Hou, Jing; Lu, Lili; Qi, Zihao; Sun, Jianmin; Gao, Wen; Meng, Jiao; Wang, Yan; Sun, Huizhen; Gu, Hongyu; Xin, Yuhu; Guo, Xiaomao; Yang, Gong

    2013-01-01

    Small ribosomal protein subunit S7 (RPS7) has been reported to be associated with various malignancies, but the role of RPS7 in ovarian cancer remains unclear. In this study, we found that silencing of RPS7 by a specific shRNA promoted ovarian cancer cell proliferation, accelerated cell cycle progression, and slightly reduced cell apoptosis and response to cisplatin treatment. Knockdown of RPS7 resulted in increased expression of P85α, P110α, and AKT2. Although the basal levels of ERK1/2, MEK1/2, and P38 were inconsistently altered in ovarian cancer cells, the phosphorylated forms of MEK1/2 (Ser217/221), ERK1/2 (Thr202/Tyr204), JNK1/2 (Thr183/Tyr185), and P38 (Thr180/Tyr182) were consistently reduced after RPS7 was silenced. Both the in vitro anchorage-independent colony formation and in vivo animal tumor formation capability of cells were enhanced after RPS7 was depleted. We also showed that silencing of RPS7 enhanced ovarian cancer cell migration and invasion. In sum, our results suggest that RPS7 suppresses ovarian tumorigenesis and metastasis through PI3K/AKT and MAPK signal pathways. Thus, RPS7 may be used as a potential marker for diagnosis and treatment of ovarian cancer.

  16. Paeoniflorin ameliorates ANIT-induced cholestasis by activating Nrf2 through an PI3K/Akt-dependent pathway in rats.

    PubMed

    Chen, Zhe; Ma, Xiao; Zhu, Yun; Zhao, Yanling; Wang, Jiabo; Li, Ruisheng; Chen, Chang; Wei, Shizhang; Jiao, Wenjuan; Zhang, Yaming; Li, Jianyu; Wang, Lifu; Wang, Ruilin; Liu, Honghong; Shen, Honghui; Xiao, Xiaohe

    2015-11-01

    Cholestasis causes hepatic accumulation of bile acids leading to liver injury, fibrosis and liver failure. Paeoniflorin, the major active compound isolated from the roots of Paeonia lactiflora pall and Paeonia veitchii Lynch, is extensively used for liver diseases treatment in China. However, the mechanism of paeoniflorin's hepatoprotective effect on cholestasis has not been investigated yet. In this study, we administered paeoniflorin to rats for 3 days prior to alpha-naphthylisothiocyanate (ANIT) administration for once, then went on administering paeoniflorin to rats for 3 days. The data demonstrated that paeoniflorin significantly prevented ANIT-induced change in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphates (ALP), serum total bilirubin (TBIL), direct bilirubin (DBIL), total bile acid (TBA) and gamma-glutamyl transpeptidase (γ-GT). Histology examination revealed that paeoniflorin treatment rats relieved more liver injury and bile duct proliferation than ANIT-administered rats. Moreover, our data indicated that paeoniflorin could restore glutathione (GSH) and its related synthase glutamate-cysteine ligase catalytic subunit (GCLc) and glutamate-cysteine ligase modifier subunit (GCLm) in ANIT-treated group. In addition, the RNA and protein expression of Akt and nuclear factor-E2-related factor-2 (Nrf2) were also activated by paeoniflorin in ANIT-induced rats. These findings indicated that paeoniflorin protected ANIT-induced cholestasis and increased GSH synthesis by activating Nrf2 through PI3K/Akt-dependent pathway. Therefore, paeoniflorin might be a potential therapeutic agent for cholestasis. PMID:26269092

  17. Gelsolin-mediated activation of PI3K/Akt pathway is crucial for hepatocyte growth factor-induced cell scattering in gastric carcinoma.

    PubMed

    Huang, Baohua; Deng, Shuo; Loo, Ser Yue; Datta, Arpita; Yap, Yan Lin; Yan, Benedict; Ooi, Chia Huey; Dinh, Thuy Duong; Zhuo, Jingli; Tochhawng, Lalchhandami; Gopinadhan, Suma; Jegadeesan, Tamilarasi; Tan, Patrick; Salto-Tellez, Manuel; Yong, Wei Peng; Soong, Richie; Yeoh, Khay Guan; Goh, Yaw Chong; Lobie, Peter E; Yang, Henry; Kumar, Alan Prem; Maciver, Sutherland K; So, Jimmy B Y; Yap, Celestial T

    2016-05-01

    In gastric cancer (GC), the main subtypes (diffuse and intestinal types) differ in pathological characteristics, with diffuse GC exhibiting early disseminative and invasive behaviour. A distinctive feature of diffuse GC is loss of intercellular adhesion. Although widely attributed to mutations in the CDH1 gene encoding E-cadherin, a significant percentage of diffuse GC do not harbor CDH1 mutations. We found that the expression of the actin-modulating cytoskeletal protein, gelsolin, is significantly higher in diffuse-type compared to intestinal-type GCs, using immunohistochemical and microarray analysis. Furthermore, in GCs with wild-type CDH1, gelsolin expression correlated inversely with CDH1 gene expression. Downregulating gelsolin using siRNA in GC cells enhanced intercellular adhesion and E-cadherin expression, and reduced invasive capacity. Interestingly, hepatocyte growth factor (HGF) induced increased gelsolin expression, and gelsolin was essential for HGF-medicated cell scattering and E-cadherin transcriptional repression through Snail, Twist and Zeb2. The HGF-dependent effect on E-cadherin was found to be mediated by interactions between gelsolin and PI3K-Akt signaling. This study reveals for the first time a function of gelsolin in the HGF/cMet oncogenic pathway, which leads to E-cadherin repression and cell scattering in gastric cancer. Our study highlights gelsolin as an important pro-disseminative factor contributing to the aggressive phenotype of diffuse GC.

  18. Hypoxic Preconditioning Inhibits Hypoxia-induced Apoptosis of Cardiac Progenitor Cells via the PI3K/Akt-DNMT1-p53 Pathway

    PubMed Central

    Xu, Rongfeng; Sun, Yuning; Chen, Zhongpu; Yao, Yuyu; Ma, Genshan

    2016-01-01

    Research has demonstrated that hypoxic preconditioning (HP) can enhance the survival and proliferation of cardiac progenitor cells (CPCs); however, the underlying mechanisms are not fully understood. Here, we report that HP of c-kit (+) CPCs inhibits p53 via the PI3K/Akt-DNMT1 pathway. First, CPCs were isolated from the hearts of C57BL/6 mice and further purified by magnetic-activated cell sorting. Next, these cells were cultured under either normoxia (H0) or HP for 6 hours (H6) followed by oxygen–serum deprivation for 24 hours (24h). Flow cytometric analysis and MTT assays revealed that hypoxia-preconditioned CPCs exhibited an increased survival rate. Western blot and quantitative real-time PCR assays showed that p53 was obviously inhibited, while DNMT1 and DNMT3β were both significantly up-regulated by HP. Bisulphite sequencing analysis indicated that DNMT1 and DNMT3β did not cause p53 promoter hypermethylation. A reporter gene assay and chromatin immunoprecipitation analysis further demonstrated that DNMT1 bound to the promoter locus of p53 in hypoxia-preconditioned CPCs. Together, these observations suggest that HP of CPCs could lead to p53 inhibition by up-regulating DNMT1 and DNMT3β, which does not result in p53 promoter hypermethylation, and that DNMT1 might directly repress p53, at least in part, by binding to the p53 promoter locus. PMID:27488808

  19. MicroRNA-7 inhibits the stemness of prostate cancer stem-like cells and tumorigenesis by repressing KLF4/PI3K/Akt/p21 pathway

    PubMed Central

    Chang, Yun-Li; Zhou, Pei-Jie; Wei, Lianzi; Li, Wang; Ji, Zhongzhong; Fang, Yu-Xiang; Gao, Wei-Qiang

    2015-01-01

    Up to now, the molecular mechanisms underlying the stemness of prostate cancer stem cells (PCSCs) are still poorly understood. In this study, we demonstrated that microRNA-7 (miR-7) appears to be a novel tumor-suppressor miRNA, which abrogates the stemness of PCSCs and inhibits prostate tumorigenesis by suppressing a key stemness factor KLF4. MicroRNA-7 is down-regulated in prostate cancer cells compared to non-tumorigenic prostate epithelial cells. Restoration of miR-7 suppresses the expression of the stemness factor KLF4 in PCSCs and inhibits prostate tumorigenesis both in vitro and in vivo. Interestingly, the suppression of the stemness of PCSCs by miR-7 is sustained for generations in xenografts. Analysis of clinical samples also revealed a negative correlation between miR-7 expression and prostate tumor progression. Mechanistically, overexpression of miR-7 may lead to a cell cycle arrest but not apoptosis, which seems achieved via suppressing the KLF4/PI3K/Akt/p21 pathway. This study identifies miR-7 as a suppressor of PCSCs' stemness and implicates its potential application for PCa therapy. PMID:26172296

  20. Xyloketal B suppresses glioblastoma cell proliferation and migration in vitro through inhibiting TRPM7-regulated PI3K/Akt and MEK/ERK signaling pathways.

    PubMed

    Chen, Wen-Liang; Turlova, Ekaterina; Sun, Christopher L F; Kim, Ji-Sun; Huang, Sammen; Zhong, Xiao; Guan, Yong-Yuan; Wang, Guan-Lei; Rutka, James T; Feng, Zhong-Ping; Sun, Hong-Shuo

    2015-04-01

    Glioblastoma, the most common and aggressive type of brain tumors, has devastatingly proliferative and invasive characteristics. The need for finding a novel and specific drug target is urgent as the current approaches have limited therapeutic effects in treating glioblastoma. Xyloketal B is a marine compound obtained from mangrove fungus Xylaria sp. (No. 2508) from the South China Sea, and has displayed antioxidant activity and protective effects on endothelial and neuronal oxidative injuries. In this study, we used a glioblastoma U251 cell line to (1) explore the effects of xyloketal B on cell viability, proliferation, and migration; and (2) investigate the underlying molecular mechanisms and signaling pathways. MTT assay, colony formation, wound healing, western blot, and patch clamp techniques were employed. We found that xyloketal B reduced cell viability, proliferation, and migration of U251 cells. In addition, xyloketal B decreased p-Akt and p-ERK1/2 protein expressions. Furthermore, xyloketal B blocked TRPM7 currents in HEK-293 cells overexpressing TRPM7. These effects were confirmed by using a TRPM7 inhibitor, carvacrol, in a parallel experiment. Our findings indicate that TRPM7-regulated PI3K/Akt and MEK/ERK signaling is involved in anti-proliferation and migration effects of xyloketal B on U251 cells, providing in vitro evidence for the marine compound xyloketal B to be a potential drug for treating glioblastoma.

  1. Calorie restriction in humans inhibits the PI3K/AKT pathway and induces a younger transcription profile

    PubMed Central

    Mercken, Evi M.; Crosby, Seth D.; Lamming, Dudley W.; JeBailey, Lellean; Krzysik-Walker, Susan; Villareal, Dennis; Capri, Miriam; Franceschi, Claudio; Zhang, Yongqing; Becker, Kevin; Sabatini, David M.; de Cabo, Rafael; Fontana, Luigi

    2013-01-01

    Summary Caloric restriction (CR) and down-regulation of the insulin/IGF pathway are the most robust interventions known to increase longevity in lower organisms. However, little is known about the molecular adaptations induced by CR in humans. Here we report that long-term CR in humans inhibits the IGF-1/insulin pathway in skeletal muscle, a key metabolic tissue. We also demonstrate that CR-induced dramatic changes of the skeletal muscle transcriptional profile that resemble those of younger individuals. Finally, in both rats and humans CR evoked similar responses in the transcriptional profiles of skeletal muscle. This common signature consisted of three key pathways typically associated with longevity: IGF-1/insulin signaling, mitochondrial biogenesis and inflammation. Furthermore, our data identifies promising pathways for therapeutic targets to combat age-related diseases and promote health in humans. PMID:23601134

  2. Energy Balance, the PI3K-AKT-mTOR Pathway Genes and the Risk of Bladder Cancer

    PubMed Central

    Lin, Jie; Wang, Jianming; Greisinger, Anthony J.; Grossman, H. Barton; Forman, Michele R.; Dinney, Colin P.; Hawk, Ernest T.; Wu, Xifeng

    2010-01-01

    We evaluated the association between energy balance and risk of bladder cancer and assessed joint effects of genetic variants in the mTOR pathway genes with energy balance. The study included 803 Caucasian bladder cancer patients and 803 healthy Caucasian controls matched to cases by age (± 5 years) and gender. High energy intake (OR=1.60; 95% CI=1.23-2.09) and low physical activity (OR=2.82; 95% CI=2.10-3.79) were each associated with significantly increased risk of bladder cancer with dose-response trends (P for trend<0.001). However, obesity (BMI ≥30) was not associated with the risk. Among 222 SNPs, 28 SNPs located in 6 genes of mTOR pathway were significantly associated with the risk. Further, the risk associated with high energy intake and low physical activity was only observed among subjects carrying a high number of unfavorable genotypes in the pathway. Moreover, when physical activity, energy intake and genetic variants were analyzed jointly, the study population was clearly stratified into a range of low to high risk subgroups as defined energy balance status. Compared to subjects within the most favorable energy balance category (low energy intake, intensive physical activity, low number of unfavorable genotypes), subjects in the worst energy balance category (high energy intake, low physical activity, and carrying seven or more unfavorable genotypes) had 21.93-fold increased risk (95% CI=6.7 to 71.77). Our results provide the first strong support that physical activity, energy intake and genetic variants in the mTOR pathway jointly influence bladder cancer susceptibility and these results have implications in bladder cancer prevention. PMID:20354165

  3. Apelin induces vascular smooth muscle cells migration via a PI3K/Akt/FoxO3a/MMP-2 pathway.

    PubMed

    Wang, Cheng; Wen, Jianyan; Zhou, Yun; Li, Li; Cui, Xiaobing; Wang, Jinyu; Pan, Lin; Ye, Zhidong; Liu, Peng; Wu, Liling

    2015-12-01

    Apelin is an adipokine that has a critical role in the development of atherosclerosis, which may offer potential for therapy. Because migration of vascular smooth muscle cells (VSMCs) is a key event in the development of atherosclerosis, understanding its effect on the atherosclerotic vasculature is needed. Here we investigated the effect of apelin on VSMC migration and the possible signaling mechanism. In cultured rat VSMCs, apelin dose- and time-dependently promoted VSMC migration. Apelin increased the phosphorylation of Akt, whereas LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K), and an Akt1/2 kinase inhibitor blocked the apelin-induced VSMC migration. Apelin dose-dependently induced phosphorylation of Forkhead box O3a (FoxO3a) and promoted its translocation from the nucleus to cytoplasm, which were blocked by LY294002 and Akt1/2 kinase inhibitor. Furthermore, apelin increased matrix metalloproteinase 2 (MMP-2) expression and gelatinolytic activity. Overexpression of a constitutively active, phosphorylation-resistant mutant, TM-FoxO3a, in VSMCs abrogated the effect of apelin on MMP-2 expression and VSMC migration. ARP101, an inhibitor of MMP-2, suppressed apelin-induced VSMC migration. Moreover, the levels of apelin, phosphorylated Akt, FoxO3a, and MMP-2 were higher in human carotid-artery atherosclerotic plaque than in adjacent normal vessels. We demonstrate that PI3K/Akt/FoxO3a signaling may be involved in apelin inducing VSMC migration. Phosphorylation of FoxO3a plays a central role in mediating the apelin-induced MMP-2 activation and VSMC migration.

  4. Heterogeneity between triple negative breast cancer cells due to differential activation of Wnt and PI3K/AKT pathways.

    PubMed

    Martínez-Revollar, Gabriela; Garay, Erika; Martin-Tapia, Dolores; Nava, Porfirio; Huerta, Miriam; Lopez-Bayghen, Esther; Meraz-Cruz, Noemí; Segovia, José; González-Mariscal, Lorenza

    2015-11-15

    The lack of a successful treatment for triple-negative breast cancer demands the study of the heterogeneity of cells that constitute these tumors. With this aim, two clones from triple negative breast MDA-MB-231 cancer cells were isolated: One with fibroblast-like appearance (F) and another with semi-epithelial (SE) morphology. Cells of the F clone have a higher migration and tumorigenesis capacity than SE cells, suggesting that these cells are in a more advanced stage of epithelial to mesenchymal transformation. In agreement, F cells have a diminished expression of the tight junction proteins claudins 1 and 4, and an increased content of β-catenin. The latter is due to an augmented activity of the canonical Wnt route and of the EGFR/PI3K/mTORC2/AKT pathway favoring the cytoplasmic accumulation of β-catenin and its transcriptional activity. In addition, F cells display increased phosphorylation of β-catenin at Tyr654 by Src. These changes favor in F cells, the over-expression of Snail that promotes EMT. Finally, we observe that both F and SE cells display markers of cancer stem cells, which are more abundant in the F clone.

  5. Arginine ADP-ribosyltransferase 1 promotes angiogenesis in colorectal cancer via the PI3K/Akt pathway.

    PubMed

    Yang, Lian; Xiao, Ming; Li, Xian; Tang, Yi; Wang, Ya-Lan

    2016-03-01

    Arginine adenosine diphosphate (ADP)-ribosyl-transferase 1 (ART1) is known to play an important role in many physiological and pathological processes. Previous studies have demonstrated that ART1 promotes proliferation, invasion and metastasis in colon carcinoma. However, it was unclear whether ART1 is involved in angiogenesis in cases of colorectal cancer (CRC). In the present study, lentiviral vector‑mediated ART1‑cDNA or ART1-shRNA were transfected into LoVo cells, and the LoVo cells transfected with ART1-cDNA or ART1-shRNA were co-cultured with human umbilical vein endothelial cells (HUVECs) to determine the influence of ART1 on HUVECs. The proliferation, migration and angiogenesis of HUVECs were monitored using a cell counting kit-8 assay, a Transwell migration assay and immunohistochemical analysis in intrasplenic allograft tumors, respectively. Hypoxia‑inducible factor 1-α (HIF-1α), total (t-)Akt, phosphorylated (p-)Akt, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) expression levels were detected via western blot analysis. Our results revealed that HUVECs which were co-cultured with ART1-cDNA LoVo cells showed higher proliferation, migration and angiogenic abilities, but a reduction was noted in those cultured with ART1-shRNA LoVo cells; p-Akt, HIF-1α, VEGF and bFGF expression was increased in HUVECs cultured with ART1‑cDNA-transfected LoVo cells, but reduced in ART1-shRNA-transfected LoVo cells. In a mouse xenograft model, we noted that the tumor microvessel density (MVD) was significantly increased in intrasplenic transplanted ART1‑cDNA CT26 tumors but decreased in intrasplenic transplanted ART1‑shRNA tumors. These data suggest that ART1 promoted the expression of HIF-1α via the Akt pathway in tumor cells. It also upregulated VEGF and bFGF and enhanced angiogenesis in HUVECs. Thus, we suggest that ART1 plays an important role in the invasion of CRC cells and the metastasis of CRC.

  6. Hepatocyte growth factor (HGF) upregulates heparanase expression via the PI3K/Akt/NF-κB signaling pathway for gastric cancer metastasis.

    PubMed

    Hao, Ning-Bo; Tang, Bo; Wang, Guo-Zheng; Xie, Rui; Hu, Chang-Jiang; Wang, Su-Min; Wu, Yu-Yun; Liu, En; Xie, Xia; Yang, Shi-Ming

    2015-05-28

    Heparanase (HPA) is an endoglucuronidase that can promote the shedding of associated cytokines in several types of tumors. However, little is known about what controls the expression of HPA or its role in gastric cancer. In this study, we report for the first time that HGF regulates HPA expression to promote gastric cancer metastasis. In this study, HGF and HPA were found to be significantly expressed in 58 gastric cancer patients. High expression of both HGF and HPA was positively associated with TNM stage, invasion depth and poor prognosis. In MKN74 cells, exogenous HGF significantly increased HPA expression at both the mRNA and protein levels. Further study revealed that HGF first activated PI3K/Akt signaling. NF-κB signaling was activated downstream of PI3K/Akt and promoted HPA expression. However, when c-met, PI3K/Akt or NF-κB signal inhibitors were used, HPA expression was significantly decreased. All of these results indicate that HGF regulates HPA expression by PI3K/Akt and downstream NF-κB signaling. Using bioinformatics and the ChIP assay, p65 was observed to bind to the HPA promoter. Furthermore, HGF significantly induced tumor cell migration, whereas treatment with an NF-κB inhibitor decreased migration. Moreover, when HPA was overexpressed in MKN74 cells, migration was significantly enhanced, and the HGF concentration was increased. However, when HPA was down-regulated in MKN45 cells, migration and HGF levels decreased. Together, these results demonstrate that HGF/c-met can activate PI3K/Akt and downstream NF-κB signaling to promote HPA expression and subsequent tumor metastasis.

  7. Activation of the PI3K/Akt signal transduction pathway and increased levels of insulin receptor in protein repair-deficient mice.

    PubMed

    Farrar, Christine; Houser, Carolyn R; Clarke, Steven

    2005-02-01

    Protein L-isoaspartate (D-aspartate) O-methyltransferase is an enzyme that catalyses the repair of isoaspartyl damage in proteins. Mice lacking this enzyme (Pcmt1-/- mice) have a progressive increase in brain size compared with wild-type mice (Pcmt1+/+ mice), a phenotype that can be associated with alterations in the PI3K/Akt signal transduction pathway. Here we show that components of this pathway, including Akt, GSK3beta and PDK-1, are more highly phosphorylated in the brains of Pcmt1-/- mice, particularly in cells of the hippocampus, in comparison with Pcmt1+/+ mice. Examination of upstream elements of this pathway in the hippocampus revealed that Pcmt1-/- mice have increased activation of insulin-like growth factor-I (IGF-I) receptor and/or insulin receptor. Western blot analysis revealed an approximate 200% increase in insulin receptor protein levels and an approximate 50% increase in IGF-I receptor protein levels in the hippocampus of Pcmt1-/- mice. Higher levels of the insulin receptor protein were also found in other regions of the adult brain and in whole tissue extracts of brain, liver, heart and testes of both juvenile and adult Pcmt1-/- mice. There were no significant differences in plasma insulin levels for adult Pcmt1-/- mice during glucose tolerance tests. However, they did show higher peak levels of blood glucose, suggesting a mild impairment in glucose tolerance. We propose that Pcmt1-/- mice have altered regulation of the insulin pathway, possibly as a compensatory response to altered glucose uptake or metabolism or as an adaptive response to a general accumulation of isoaspartyl protein damage in the brain and other tissues.

  8. Growth-factor dependent expression of the translationally controlled tumour protein TCTP is regulated through the PI3-K/Akt/mTORC1 signalling pathway.

    PubMed

    Bommer, Ulrich-Axel; Iadevaia, Valentina; Chen, Jiezhong; Knoch, Bianca; Engel, Martin; Proud, Christopher G

    2015-08-01

    Translationally controlled tumour protein TCTP (gene symbol: TPT1) is a highly-conserved, cyto-protective protein implicated in many physiological and disease processes, in particular cancer, where it is associated with poor patient outcomes. To understand the mechanisms underlying the accumulation of high TCTP levels in cancer cells, we studied the signalling pathways that control translation of TCTP mRNA, which contains a 5'-terminal oligopyrimidine tract (5'-TOP). In HT29 colon cancer cells and in HeLa cells, serum increases the expression of TCTP two- and four-fold, respectively, and this is inhibited by rapamycin or mTOR kinase inhibitors. Polysome profiling and mRNA quantification indicate that these effects occur at the level of mRNA translation. Blocking this pathway upstream of mTOR complex 1 (mTORC1) by inhibiting Akt also prevented increases in TCTP levels in both HeLa and HT29 colon cancer cells, whereas knockout of TSC2, a negative regulator of mTORC1, led to derepression of TCTP synthesis under serum starvation. Overexpression of eIF4E enhanced the polysomal association of the TCTP mRNA, although it did not protect its translation from inhibition by rapamycin. Conversely, expression of a constitutively-active mutant of the eIF4E inhibitor 4E-BP1, which is normally inactivated by mTORC1, inhibited TCTP mRNA translation in HEK293 cells. Our results demonstrate that TCTP mRNA translation is regulated by signalling through the PI3-K/Akt/mTORC1 pathway. This explains why TCTP levels are frequently increased in cancers, since mTORC1 signalling is hyperactive in ~80% of tumours.

  9. Radiation persistently promoted oxidative stress, activated mTOR via PI3K/Akt, and downregulated autophagy pathway in mouse intestine.

    PubMed

    Datta, Kamal; Suman, Shubhankar; Fornace, Albert J

    2014-12-01

    While acute effects of toxic radiation doses on intestine are well established, we are yet to acquire a complete spectrum of sub-lethal radiation-induced chronic intestinal perturbations at the molecular level. We investigated persistent effects of a radiation dose (2 Gy) commonly used as a daily fraction in radiotherapy on oxidants and anti-oxidants, and autophagy pathways, which are interlinked processes affecting intestinal homeostasis. Six to eight weeks old C57BL/6J mice (n=10) were exposed to 2 Gy γ-ray. Mice were euthanized two or twelve months after radiation, intestine surgically removed, and flushed using sterile PBS. Parts of the intestine from jejunal-ilial region were fixed, frozen, or used for intestinal epithelial cell (IEC) isolation. While oxidant levels and mitochondrial status were assessed in isolated IEC, autophagy and oxidative stress related signaling pathways were probed in frozen and fixed samples using PCR-based expression arrays and immunoprobing. Radiation exposure caused significant alterations in the expression level of 26 autophagy and 17 oxidative stress related genes. Immunoblot results showed decreased Beclin1 and LC3-II and increased p62, PI3K/Akt, and mTOR. Flow cytometry data showed increased oxidant production and compromised mitochondrial integrity in irradiated samples. Immunoprobing of intestinal sections showed increased 8-oxo-dG and nuclear PCNA, and decreased autophagosome marker LC3-II in IEC after irradiation. We show that sub-lethal radiation could persistently downregulate anti-oxidants and autophagy signaling, and upregulate oxidant production and proliferative signaling. Radiation-induced promotion of oxidative stress and downregulation of autophagy could work in tandem to alter intestinal functions and have implications for post-radiation chronic gastrointestinal diseases.

  10. Protracted upregulation of leptin and IGF1 is associated with activation of PI3K/Akt and JAK2 pathway in mouse intestine after ionizing radiation exposure.

    PubMed

    Suman, Shubhankar; Kallakury, Bhaskar V S; Fornace, Albert J; Datta, Kamal

    2015-01-01

    Ionizing radiation is a known risk factor for gastrointestinal (GI) pathologies including cancer. Hormones and related signaling crosstalk, which could contribute to radiation-induced persistent pathophysiologic changes in the small intestine and colon, remain to be explored. The current study assessed perturbation of GI homeostasis-related hormones and signaling pathways at the systemic as well as at the tissue level in small intestine and colon. Mice (6-8 week old C57BL/6J) were exposed to 2 Gy γ radiation, serum and tissue samples were collected, and insulin like growth factor 1 (IGF-1) and leptin signaling were assessed two or twelve months after radiation exposure. Serum levels of IGF-1, IGF binding protein 3 (IGFBP3), leptin, and adiponectin were altered at these times after irradiation. Radiation was associated with increased IGF1 receptor (IGF1R) and obesity (leptin) receptor (Ob-R), decreased adiponectin receptor 1 (Adipo-R1) and 2 (Adipo-R2), and increased Ki-67 levels in small intestine and colon at both time points. Immunoblot analysis further showed increased IGF1R and Ob-R, and decreased Adipo-R2. Additionally, upregulation of PI3K/Akt and JAK2 signaling, which are downstream of IGF1 and leptin, was also observed in irradiated samples at both time points. These results when considered along with increased cell proliferation in the small intestine and colon demonstrate for the first time that ionizing radiation can persistently increase IGF1 and leptin and activate downstream proliferative pathways, which may contribute to GI functional alterations and carcinogenesis.

  11. Helicobacter pylori VacA-induced Inhibition of GSK3 through the PI3K/Akt Signaling Pathway*S⃞

    PubMed Central

    Nakayama, Masaaki; Hisatsune, Junzo; Yamasaki, Eiki; Isomoto, Hajime; Kurazono, Hisao; Hatakeyama, Masanori; Azuma, Takeshi; Yamaoka, Yoshio; Yahiro, Kinnosuke; Moss, Joel; Hirayama, Toshiya

    2009-01-01

    Helicobacter pylori VacA toxin contributes to the pathogenesis and severity of gastric injury. We found that incubation of AZ-521 cells with VacA resulted in phosphorylation of protein kinase B (Akt) and glycogen synthase kinase-3β (GSK3β) through a PI3K-dependent pathway. Following phosphorylation and inhibition of GSK3β,β-catenin was released from a GSK3β/β-catenin complex, with subsequent nuclear translocation. Methyl-β-cyclodextrin (MCD) and phosphatidylinositol-specific phospholipase C (PI-PLC), but not 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) and bafilomycin A1, inhibited VacA-induced phosphorylation of Akt, indicating that it does not require VacA internalization and is independent of vacuolation. VacA treatment of AZ-521 cells transfected with TOPtkLuciferase reporter plasmid or control FOPtkLucifease reporter plasmid resulted in activation of TOPtkLuciferase, but not FOPtkLucifease. In addition, VacA transactivated the β-catenin-dependent cyclin D1 promoter in a luciferase reporter assay. Infection of AZ-521 cells by a vacA mutant strain of H. pylori failed to induce phosphorylation of Akt and GSK3β, or release of β-catenin from a GSK3β/β-catenin complex. Taken together, these results support the conclusion that VacA activates the PI3K/Akt signaling pathway, resulting in phosphorylation and inhibition of GSK3β, and subsequent translocation ofβ-catenin to the nucleus, consistent with effects of VacA on β-catenin-regulated transcriptional activity. These data introduce the possibility that Wnt-dependent signaling might play a role in the pathogenesis of H. pylori infection, including the development of gastric cancer. PMID:18996844

  12. Porcine circovirus type 2 activates PI3K/Akt and p38 MAPK pathways to promote interleukin-10 production in macrophages via Cap interaction of gC1qR

    PubMed Central

    Wang, Tongtong; Zhang, Xiujuan; Chen, Yu; Cui, Beibei; Li, Delong; Zhao, Xiaomin; Zhang, Wenlong; Chang, Lingling; Tong, Dewen

    2016-01-01

    Porcine circovirus type 2 (PCV2) infection caused PCV2-associated diseases (PCVAD) is one of the major emerging immunosuppression diseases in pig industry. In this study, we investigated how PCV2 inoculation increases interleukin (IL)-10 expression in porcine alveolar macrophages (PAMs). PCV2 inoculation significantly upregulated IL-10 expression compared with PCV1. Upon initial PCV2 inoculation, PI3K/Akt cooperated with NF-κB pathways to promote IL-10 transcription via p50, CREB and Ap1 transcription factors, whereas inhibition of PI3K/Akt activation blocked Ap1 and CREB binding to the il10 promoter, and decreased the binding level of NF-κB1 p50 with il10 promoter, leading to great reduction in early IL-10 transcription. In the later phase of inoculation, PCV2 further activated p38 MAPK and ERK pathways to enhance IL-10 production by promoting Sp1 binding to the il10 promoter. For PCV2-induced IL-10 production in macrophages, PCV2 capsid protein Cap, but not the replicase Rep or ORF3, was the critical component. Cap activated PI3K/Akt, p38 MAPK, and ERK signaling pathways to enhance IL-10 expression. In the whole process, gC1qR mediated PCV2-induced PI3K/Akt and p38 MAPK activation to enhance IL-10 induction by interaction with Cap. Depletion of gC1qR blocked PI3K/Akt and p38 MAPK activation, resulting in significant decrease in IL-10 production in PCV2-inoculated cells. Thus, gC1qR might be a critical functional receptor for PCV2-induced IL-10 production. Taken together, these data demonstrated that Cap protein binding with host gC1qR induction of PI3K/Akt and p38 MAPK signalings activation is a critical process in enhancing PCV2-induced IL-10 production in porcine alveolar macrophages. PMID:26883107

  13. Porcine circovirus type 2 activates PI3K/Akt and p38 MAPK pathways to promote interleukin-10 production in macrophages via Cap interaction of gC1qR.

    PubMed

    Du, Qian; Huang, Yong; Wang, Tongtong; Zhang, Xiujuan; Chen, Yu; Cui, Beibei; Li, Delong; Zhao, Xiaomin; Zhang, Wenlong; Chang, Lingling; Tong, Dewen

    2016-04-01

    Porcine circovirus type 2 (PCV2) infection caused PCV2-associated diseases (PCVAD) is one of the major emerging immunosuppression diseases in pig industry. In this study, we investigated how PCV2 inoculation increases interleukin (IL)-10 expression in porcine alveolar macrophages (PAMs). PCV2 inoculation significantly upregulated IL-10 expression compared with PCV1. Upon initial PCV2 inoculation, PI3K/Akt cooperated with NF-κB pathways to promote IL-10 transcription via p50, CREB and Ap1 transcription factors, whereas inhibition of PI3K/Akt activation blocked Ap1 and CREB binding to the il10 promoter, and decreased the binding level of NF-κB1 p50 with il10 promoter, leading to great reduction in early IL-10 transcription. In the later phase of inoculation, PCV2 further activated p38 MAPK and ERK pathways to enhance IL-10 production by promoting Sp1 binding to the il10 promoter. For PCV2-induced IL-10 production in macrophages, PCV2 capsid protein Cap, but not the replicase Rep or ORF3, was the critical component. Cap activated PI3K/Akt, p38 MAPK, and ERK signaling pathways to enhance IL-10 expression. In the whole process, gC1qR mediated PCV2-induced PI3K/Akt and p38 MAPK activation to enhance IL-10 induction by interaction with Cap. Depletion of gC1qR blocked PI3K/Akt and p38 MAPK activation, resulting in significant decrease in IL-10 production in PCV2-inoculated cells. Thus, gC1qR might be a critical functional receptor for PCV2-induced IL-10 production. Taken together, these data demonstrated that Cap protein binding with host gC1qR induction of PI3K/Akt and p38 MAPK signalings activation is a critical process in enhancing PCV2-induced IL-10 production in porcine alveolar macrophages. PMID:26883107

  14. Lentiviral shRNA against KCa3.1 inhibits allergic response in allergic rhinitis and suppresses mast cell activity via PI3K/AKT signaling pathway

    PubMed Central

    Lin, Hai; Zheng, Chunquan; Li, Jing; Yang, Chen; Hu, Li

    2015-01-01

    Calcium-activated potassium ion channel-3.1 (KCa3.1) plays a pivotal role in the potassium-calcium exchange involved in atopy. This study aimed to explore the impact of lentiviral-mediated shRNA silencing KCa3.1 on allergic response in a murine allergic rhinitis (AR) model. The BALB/c mice were divided into four groups: untreated AR group, negative control AR group, lentiviral KCa3.1-shRNA treated AR group and normal control group. Concentrations of ovalbumin (OVA)-specific IgE, histamine and leukotrienes C4 (LTC4) in serum, and IL-4, IL-9 and IL-17 in nasal lavage fluid (NLF) were analyzed. Goblet cells and mast cells were counted. KCa3.1 positive cells were counted after immunolabelling by immunofluorescence method. KCa3.1, Mucin 5AC (MUC5AC), and tryptase mRNA levels were determined using real-time polymerase chain reaction. Furthermore, P815 cell line was used to explore the role and mechanism of lentiviral KCa3.1-shRNA on mast cells. The results showed that LV-KCa3.1-shRNA intervention effectively attenuated allergic responses in LV-KCa3.1-shRNA treated mice. LV-KCa3.1-shRNA intervention effectively suppressed KCa3.1 levels and phosphorylation of AKT in P815 cells, leading to the downregulation of tryptase, IL-6 and IL-8 levels. LV-KCa3.1-shRNA intervention effectively attenuated the allergic responses in AR and suppressed mast cell activity by inhibiting PI3K/AKT signaling pathway. PMID:26272420

  15. Andrographolide inhibits growth of human T-cell acute lymphoblastic leukemia Jurkat cells by downregulation of PI3K/AKT and upregulation of p38 MAPK pathways

    PubMed Central

    Yang, Tingfang; Yao, Shuluan; Zhang, Xianfeng; Guo, Yan

    2016-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) as a prevalent hematologic malignancy is one of the most common malignant tumors worldwide in children. Andrographolide (Andro), the major active component from Andrographis paniculata, has been shown to possess antitumor activities in several types of cancer cells. However, whether Andro would inhibit T-ALL cell growth remains unclear. In this study, we investigated the cytotoxic effect of Andro on human T-ALL Jurkat cells and explored the mechanisms of cell death. Cell apoptosis was assayed by flow cytometry, and the signaling transduction for Andro was analyzed by Western blotting. The results indicated 10 μg/mL Andro could significantly induce Jurkat cells’ apoptosis, depending on the inhibition of PI3K/AKT pathway. Moreover, Andro-induced apoptosis is enhanced by AKT-selective inhibitor LY294002. ERK- or JNK-selective inhibitors PD98059 and SP600125 had no effect on Andro-induced apoptosis. In addition, p38 inhibitor SB203580 could reverse Andro-induced apoptosis in Jurkat cells. We also found that the protein expression of p-p53 and p-p38 were increased after Andro treatments. The result of an in vivo study also demonstrated Andro’s dose-dependent inhibition in subcutaneous Jurkat xenografts. In conclusion, our findings explained a novel mechanism of drug action by Andro in Jurkat cells and suggested that Andro might be developed into a new candidate therapy for T-ALL patients in the coming days. PMID:27114702

  16. Later phase cardioprotection of ischemic post-conditioning against ischemia/reperfusion injury depends on iNOS and PI3K-Akt pathway

    PubMed Central

    Wang, Gongming; Li, Xin; Wang, Hong; Wang, Yan; Zhang, Ligong; Zhang, Le; Liu, Bei; Zhang, Mengyuan

    2015-01-01

    Background: The cardioprotection of ischemic post-conditioning (IPO) has been well demonstrated after a short period of reperfusion. However, little is known about the long-term effects of IPO. This study aimed to investigate the long term cardioprotection of IPO in a rat myocardial ischemia/reperfusion model and to explore the potential mechanism. Methods and results: Rats were either sham-operated (Sham group) or underwent 30-min left anterior descending coronary artery ischemia followed by immediate reperfusion (I/R group) or post-conditioning with 5 cycles of 10-s ischemia and 10-s reperfusion (IPO group). At 24 h after reperfusion, infarct size reduced from 34.7±1.1% in I/R group to 24.9±1.3% in IPO group (P<0.05) and the iNOS expression in IPO group was 4.7-fold higher than in I/R group. iNOS inhibitor 1400 W (1 mg/kg, 5 min before postconditioning or reperfusion) prevented the increase in iNOS expression and abolished IPO-induced protection (34.4±1.0%, P>0.05 vs. I/R group). When rats were treated with PI3K inhibitor LY294002 5 min before reperfusion (0.3 mg/kg), p-Akt expression at R 3 h and iNOS expression at R 24 h were significantly inhibited. Moreover, the delayed infarct-sparing effect of IPO was absent in the presence of LY294002. Conclusion: IPO has prolonged cardioprotective effects and iNOS as an important downstream effector of PI3K-Akt pathway contributes to the delayed phase cardioprotection of IPO. PMID:26885260

  17. Flavonoids isolated from Citrus platymamma induce mitochondrial-dependent apoptosis in AGS cells by modulation of the PI3K/AKT and MAPK pathways.

    PubMed

    Lee, Ho Jeong; Nagappan, Arulkumar; Park, Hyeon Soo; Hong, Gyeong Eun; Yumnam, Silvia; Raha, Suchismita; Saralamma, Venu Venkatarame Gowda; Lee, Won Sup; Kim, Eun Hee; Kim, Gon Sup

    2015-09-01

    Citrus platymamma hort. ex Tanaka (Rutaceae family) has been widely used in Korean folk medicine for its wide range of medicinal benefits including an anticancer effect. In the present study, we aimed to investigate the molecular mechanism of the anticancer effects of flavonoids isolated from Citrus platymamma (FCP) on AGS cells. FCP treatment significantly inhibited AGS cell growth in a dose‑dependent manner. Furthermore, FCP significantly increased the percentage of cells in the sub-G1 phase (apoptotic cell population), and apoptosis was confirmed by Annexin V double staining. Chromatin condensation and apoptotic bodies were also noted in the FCP-treated AGS cells. Moreover, immunoblotting results showed that FCP treatment significantly decreased the expression of procaspase-3, -6, -8 and -9, and PARP and increased cleaved caspase-3, cleaved PARP and the Bax/Bcl-xL ratio in a dose-dependent manner. In addition, the phosphorylation of AKT was significantly decreased, whereas extracellular signal-related kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinases (MAPKs) were significantly increased in the FCP-treated AGS cells. Taken together, the cell death of AGS cells in response to FCP was mitochondrial-dependent via modulation of the PI3K/AKT and MAPK pathways. These findings provide new insight for understanding the mechanism of the anticancer effects of FCP. Thus, FCP may be a potential chemotherapeutic agent for the treatment of gastric cancer. PMID:26165353

  18. Impact of PI3K/AKT/mTOR pathway activation on the prognosis of patients with head and neck squamous cell carcinomas

    PubMed Central

    Álvarez-Teijeiro, Saúl; Hermida-Prado, Francisco; Santamaría, Iñigo; Allonca, Eva; Suárez-Fernández, Laura; Gonzalez, Maria Victoria; Balbín, Milagros; Astudillo, Aurora; Martínez-Camblor, Pablo; Su, Gloria H.; Rodrigo, Juan Pablo; García-Pedrero, Juana María

    2016-01-01

    The PI3K/AKT/mTOR signaling pathway has emerged as one of the most frequently deregulated in head and neck squamous cell carcinomas (HNSCC). Numerous alterations of various upstream and downstream components have been described; however, their prognostic significance and impact on HNSCC patient survival remains to be established. This was addressed using an unbiased cohort of 93 consecutive and homogeneous surgically treated HNSCC patients and results confirmed in 432 HNSCC patients. Our findings reveal the high prevalence of S6 phosphorylation, a surrogate marker of mTORC1 activation, in HNSCC specimens (>70%) and, more importantly, demonstrate its relevance on clinical outcome. Phosphorylation of ribosomal protein S6 on either Ser235/236 or Ser240/244 was consistently and significantly correlated with favorable prognosis, although with differences depending on the tumor site. Thus, p-S6 expression was significantly correlated with better disease-specific survival specifically in the subgroup of laryngeal carcinoma patients (P< 0.001). In addition, multivariate regression models revealed p-S6 to be an inverse and independent predictor of lymph-node metastasis (P= 0.004) and distant metastasis (P= 0.006). Taken together, this study unveils an unprecedented correlation of mTOR activation with improved clinical outcome in patients with laryngeal carcinomas and uncovers the potential of p-S6 expression as a good prognostic biomarker and an inverse predictor of lymph node and distant metastases. These results should be of broad interest as immunohistochemical detection of p-S6 may help to stratify patients and guide treatment decisions. PMID:27119232

  19. Isoquercitrin Inhibits Hydrogen Peroxide-Induced Apoptosis of EA.hy926 Cells via the PI3K/Akt/GSK3β Signaling Pathway.

    PubMed

    Zhu, Meixia; Li, Jiankuan; Wang, Ke; Hao, Xuliang; Ge, Rui; Li, Qingshan

    2016-01-01

    Oxidative stress plays a critical role in endothelial injury and the pathogenesis of diverse cardiovascular diseases, including atherosclerosis. Isoquercitrin (quercetin-3-glucoside), a flavonoid distributed widely in plants, exhibits many biological activities, including anti-allergic, anti-viral, anti-inflammatory, and anti-oxidative effects. In the present study, the inhibitory effect of isoquercitrin on H2O2-induced apoptosis of EA.hy926 cells was evaluated. MTT assays showed that isoquercitrin significantly inhibited H2O2-induced loss of viability in EA.hy926 cells. Hoechst33342/PI and Annexin V-FITC/PI fluorescent double staining indicated that isoquercitrin inhibited H2O2-induced apoptosis of EA.hy926 cells. Western blotting demonstrated that isoquercitrin prevented H2O2-induced increases in cleaved caspase-9 and cleaved caspase-3 expression, while increasing expression of anti-apoptotic protein Mcl-1. Additionally, isoquercitrin significantly increased the expression of p-Akt and p-GSK3β in a dose-dependent manner in EA.hy926 cells. LY294002, a PI3K/Akt inhibitor, inhibited isoquercitrin-induced GSK3β phosphorylation and increase of Mcl-1 expression, which indicated that regulation of isoquercitrin on Mcl-1 expression was likely related to the modulation of Akt activation. These results demonstrated that the anti-apoptotic effect of isoquercitrin on H2O2-induced EA.hy926 cells was likely associated with the regulation of isoquercitrin on Akt/GSK3β signaling pathway and that isoquercitrin could be used clinically to interfere with the progression of endothelial injury-associated cardiovascular disease. PMID:27007368

  20. Exposure to Ionizing Radiation Causes Long-Term Increase in Serum Estradiol and Activation of PI3K-Akt Signaling Pathway in Mouse Mammary Gland

    SciTech Connect

    Suman, Shubhankar; Johnson, Michael D.; Fornace, Albert J.; Datta, Kamal

    2012-10-01

    Purpose: Exposure to ionizing radiation is an established risk factor for breast cancer. Radiation exposure during infancy, childhood, and adolescence confers the highest risk. Although radiation is a proven mammary carcinogen, it remains unclear where it acts in the complex multistage process of breast cancer development. In this study, we investigated the long-term pathophysiologic effects of ionizing radiation at a dose (2 Gy) relevant to fractionated radiotherapy. Methods and Materials: Adolescent (6-8 weeks old; n = 10) female C57BL/6J mice were exposed to 2 Gy total body {gamma}-radiation, the mammary glands were surgically removed, and serum and urine samples were collected 2 and 12 months after exposure. Molecular pathways involving estrogen receptor-{alpha} (ER{alpha}) and phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling were investigated by immunohistochemistry and Western blot. Results: Serum estrogen and urinary levels of the oncogenic estrogen metabolite (16{alpha}OHE1) were significantly increased in irradiated animals. Immunostaining for the cellular proliferative marker Ki-67 and cyclin-D1 showed increased nuclear accumulation in sections of mammary glands from irradiated vs. control mice. Marked increase in p85{alpha}, a regulatory sub-unit of the PI3K was associated with increase in Akt, phospho-Akt, phospho-BAD, phospho-mTOR, and c-Myc in irradiated samples. Persistent increase in nuclear ER{alpha} in mammary tissues 2 and 12 months after radiation exposure was also observed. Conclusions: Taken together, our data not only support epidemiologic observations associating radiation and breast cancer but also, specify molecular events that could be involved in radiation-induced breast cancer.

  1. Flavonoids isolated from Citrus platymamma induce mitochondrial-dependent apoptosis in AGS cells by modulation of the PI3K/AKT and MAPK pathways.

    PubMed

    Lee, Ho Jeong; Nagappan, Arulkumar; Park, Hyeon Soo; Hong, Gyeong Eun; Yumnam, Silvia; Raha, Suchismita; Saralamma, Venu Venkatarame Gowda; Lee, Won Sup; Kim, Eun Hee; Kim, Gon Sup

    2015-09-01

    Citrus platymamma hort. ex Tanaka (Rutaceae family) has been widely used in Korean folk medicine for its wide range of medicinal benefits including an anticancer effect. In the present study, we aimed to investigate the molecular mechanism of the anticancer effects of flavonoids isolated from Citrus platymamma (FCP) on AGS cells. FCP treatment significantly inhibited AGS cell growth in a dose‑dependent manner. Furthermore, FCP significantly increased the percentage of cells in the sub-G1 phase (apoptotic cell population), and apoptosis was confirmed by Annexin V double staining. Chromatin condensation and apoptotic bodies were also noted in the FCP-treated AGS cells. Moreover, immunoblotting results showed that FCP treatment significantly decreased the expression of procaspase-3, -6, -8 and -9, and PARP and increased cleaved caspase-3, cleaved PARP and the Bax/Bcl-xL ratio in a dose-dependent manner. In addition, the phosphorylation of AKT was significantly decreased, whereas extracellular signal-related kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinases (MAPKs) were significantly increased in the FCP-treated AGS cells. Taken together, the cell death of AGS cells in response to FCP was mitochondrial-dependent via modulation of the PI3K/AKT and MAPK pathways. These findings provide new insight for understanding the mechanism of the anticancer effects of FCP. Thus, FCP may be a potential chemotherapeutic agent for the treatment of gastric cancer.

  2. Notoginsenoside Ft1 Promotes Fibroblast Proliferation via PI3K/Akt/mTOR Signaling Pathway and Benefits Wound Healing in Genetically Diabetic Mice.

    PubMed

    Zhang, Eryun; Gao, Bo; Yang, Li; Wu, Xiaojun; Wang, Zhengtao

    2016-02-01

    Wound healing requires the essential participation of fibroblasts, which is impaired in diabetic foot ulcers (DFU). Notoginsenoside Ft1 (Ft1), a saponin from Panax notoginseng, can enhance platelet aggregation by activating signaling network mediated through P2Y12 and induce proliferation, migration, and tube formation in cultured human umbilical vein endothelial cells. However, whether it can accelerate fibroblast proliferation and benefit wound healing, especially DFU, has not been elucidated. In the present study on human dermal fibroblast HDF-a, Ft1 increased cell proliferation and collagen production via PI3K/Akt/mTOR signaling pathway. On the excisional wound splinting model established on db/db diabetic mouse, topical application of Ft1 significantly shortened the wound closure time by 5.1 days in contrast with phosphate-buffered saline (PBS) treatment (15.8 versus 20.9 days). Meanwhile, Ft1 increased the rate of re-epithelialization and the amount of granulation tissue at day 7 and day 14. The molecule also enhanced mRNA expressions of COL1A1, COL3A1, transforming growth factor (TGF)-β1 and TGF-β3 and fibronectin, the genes that contributed to collagen expression, fibroblast proliferation, and consequent scar formation. Moreover, Ft1 facilitated the neovascularization accompanied with elevated vascular endothelial growth factor, platelet-derived growth factor, and fibroblast growth factor at either mRNA or protein levels and alleviated the inflammation of infiltrated monocytes indicated by reduced tumor necrosis factor-α and interleukin-6 mRNA expressions in the diabetic wounds. Altogether, these results indicated that Ft1 might accelerate diabetic wound healing by orchestrating multiple processes, including promoting fibroblast proliferation, enhancing angiogenesis, and attenuating inflammatory response, which provided a great potential application of it in clinics for patients with DFU. PMID:26567319

  3. PI3K/Akt Signaling Pathway Modulates Influenza Virus Induced Mouse Alveolar Macrophage Polarization to M1/M2b

    PubMed Central

    Zhao, Xiangfeng; Dai, Jianping; Xiao, Xuejun; Wu, Liqi; Zeng, Jun; Sheng, Jiangtao; Su, Jinghua; Chen, Xiaoxuan; Wang, Gefei; Li, Kangsheng

    2014-01-01

    Macrophages polarized to M1 (pro-inflammation) or M2 (anti-inflammation) phenotypes in response to environmental signals. In this study, we examined the polarization of alveolar macrophage (AM), following induction by different influenza virus strains (ST169 (H1N1), ST602 (H3N2) and HKG9 (H9N2)). Macrophages from other tissues or cell line exert alternative responding pattern, and AM is necessary for investigating the respiratory system. AM polarized toward the M1 phenotype after 4 hours of infection by all three virus strains, and AM to presented M2b phenotype after 8 hours induction, and immunosuppressive phenotype after 24 hours of induction. Protein expression assay showed similar results as the gene expression analysis for phenotype verification. The ELISA assay showed that TNF-α secretion was up-regulated after 4 and 8 hours of infection by influenza viruses, and it returned to basal levels after 24 hours of infection. IL-10 expression was elevated after 8 and 24 hours of infection. Immunofluorescence showed that iNOS expression was up-regulated but not Arg1 expression. Influenza virus notably increased phospho-Akt but not phospho-Erk1/2 or phospho-p38, and the AM polarization pattern have been changed by LY294002 (PI3K inhibitor). In conclusion, our results demonstrate the dynamic polarization of AM induced by influenza viruses, and suggested that PI3K/Akt signaling pathway modulates AM polarization to M1/M2b. PMID:25105760

  4. Andrographolide Analogue Induces Apoptosis and Autophagy Mediated Cell Death in U937 Cells by Inhibition of PI3K/Akt/mTOR Pathway

    PubMed Central

    Kumar, Deepak; Das, Bimolendu; Sen, Rupashree; Kundu, Priyanka; Manna, Alak; Sarkar, Avijit; Chowdhury, Chinmay; Chatterjee, Mitali; Das, Padma

    2015-01-01

    Background Current chemotherapeutic agents based on apoptosis induction are lacking in desired efficacy. Therefore, there is continuous effort to bring about new dimension in control and gradual eradication of cancer by means of ever evolving therapeutic strategies. Various forms of PCD are being increasingly implicated in anti-cancer therapy and the complex interplay among them is vital for the ultimate fate of proliferating cells. We elaborated and illustrated the underlying mechanism of the most potent Andrographolide analogue (AG–4) mediated action that involved the induction of dual modes of cell death—apoptosis and autophagy in human leukemic U937 cells. Principal Findings AG–4 induced cytotoxicity was associated with redox imbalance and apoptosis which involved mitochondrial depolarisation, altered apoptotic protein expressions, activation of the caspase cascade leading to cell cycle arrest. Incubation with caspase inhibitor Z-VAD-fmk or Bax siRNA decreased cytotoxic efficacy of AG–4 emphasising critical roles of caspase and Bax. In addition, AG–4 induced autophagy as evident from LC3-II accumulation, increased Atg protein expressions and autophagosome formation. Pre-treatment with 3-MA or Atg 5 siRNA suppressed the cytotoxic effect of AG–4 implying the pro-death role of autophagy. Furthermore, incubation with Z-VAD-fmk or Bax siRNA subdued AG–4 induced autophagy and pre-treatment with 3-MA or Atg 5 siRNA curbed AG–4 induced apoptosis—implying that apoptosis and autophagy acted as partners in the context of AG–4 mediated action. AG–4 also inhibited PI3K/Akt/mTOR pathway. Inhibition of mTOR or Akt augmented AG–4 induced apoptosis and autophagy signifying its crucial role in its mechanism of action. Conclusions Thus, these findings prove the dual ability of AG–4 to induce apoptosis and autophagy which provide a new perspective to it as a potential molecule targeting PCD for future cancer therapeutics. PMID:26436418

  5. Insulin-like growth factor-1 (IGF-1) promotes myoblast proliferation and skeletal muscle growth of embryonic chickens via the PI3K/Akt signalling pathway.

    PubMed

    Yu, Minli; Wang, Huan; Xu, Yali; Yu, Debing; Li, Dongfeng; Liu, Xiuhong; Du, Wenxing

    2015-08-01

    During embryonic development, IGF-1 fulfils crucial roles in skeletal myogenesis. However, the involvement of IGF-1-induced myoblast proliferation in muscle growth is still unclear. In the present study, we have characterised the role of IGF-1 in myoblast proliferation both in vitro and in vivo and have revealed novel details of how exogenous IGF-1 influences myogenic genes in chicken embryos. The results show that IGF-1 significantly induces the proliferation of cultured myoblasts in a dose-dependent manner. Additionally, the IGF-1 treatment significantly promoted myoblasts entering a new cell cycle and increasing the mRNA expression levels of cell cycle-dependent genes. However, these effects were inhibited by the PI3K inhibitor LY294002 and the Akt inhibitor KP372-1. These data indicated that the pro-proliferative effect of IGF-1 was mediated in response to the PI3K/Akt signalling pathway. Moreover, we also showed that exogenous IGF-1 stimulated myoblast proliferation in vivo. IGF-1 administration obviously promoted the incorporation of BrdU and remarkably increased the number of PAX7-positive cells in the skeletal muscle of chicken embryos. Administration of IGF-1 also significantly induced the upregulation of myogenic factors gene, the enhancement of c-Myc and the inhibition of myostatin (Mstn) expression. These findings demonstrate that IGF-1 has strong activity as a promoter of myoblast expansion and muscle fiber formation during early myogenesis. Therefore, this study offers insight into the mechanisms responsible for IGF-1-mediated stimulation of embryonic skeletal muscle development, which could have important implications for the improvement of chicken meat production.

  6. rLj-RGD3, a Novel Recombinant Toxin Protein from Lampetra japonica, Protects against Cerebral Reperfusion Injury Following Middle Cerebral Artery Occlusion Involving the Integrin-PI3K/Akt Pathway in Rats

    PubMed Central

    Jiang, Junshu; Wang, Shengnan; Jia, Qilan; Wang, Yue; Li, Weiping; Zhou, Qin; Lv, Li; Li, Qingwei

    2016-01-01

    Background The RGD-toxin protein Lj-RGD3 is a naturally occurring 118 amino acid peptide that can be obtained from the salivary gland of the Lampetra japonica fish. This unique peptide contains 3 RGD (Arg-Gly-Asp) motifs in its primary structure. Lj-RGD3 is available in recombinant form (rLj-RGD3) and can be produced in large quantities using DNA recombination techniques. The pharmacology of the three RGD motif-containing peptides has not been studied. This study investigated the protective effects of rLj-RGD3, a novel polypeptide, against ischemia/reperfusion-induced damage to the brain caused by middle cerebral artery occlusion (MCAO) in a rat stroke model. We also explored the mechanism by which rLj-RGD3 acts by measuring protein and mRNA expression levels, with an emphasis on the FAK and integrin-PI3K/Akt anti-apoptosis pathways. Methods rLj-RGD3 was obtained from the buccal secretions of Lampetra japonica using gene recombination technology. Sprague Dawley (SD) rats were randomly divided into the following seven groups: a sham group; a vehicle-treated (VT) group; 100.0 μg·kg-1, 50.0 μg·kg-1 and 25.0 μg·kg-1 dose rLj-RGD3 groups; and two positive controls, including 1.5 mg·kg-1 Edaravone (ED) and 100.0 μg·kg-1 Eptifibatide (EP). MCAO was induced using a model consisting of 2 h of ischemia and 24 h of reperfusion. Behavioral changes were observed in the normal and operation groups after focal cerebral ischemia/reperfusion was applied. In addition, behavioral scores were evaluated at 4 and 24 h after reperfusion. Brain infarct volumes were determined based on 2,3,5-triphenyltetrazolium chloride (TTC) staining. Pathological changes in brain tissues were observed using hematoxylin and eosin (H&E) staining. Moreover, neuronal apoptosis was detected using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assays. We determined the expression levels of focal adhesion kinase (FAK), phosphatidyl inositol 3-kinase (PI3K

  7. Polyphenols Isolated from Allium cepa L. Induces Apoptosis by Induction of p53 and Suppression of Bcl-2 through Inhibiting PI3K/Akt Signaling Pathway in AGS Human Cancer Cells

    PubMed Central

    Lee, Won Sup; Yi, Sang Mi; Yun, Jeong Won; Jung, Ji Hyun; Kim, Dong Hoon; Kim, Hye Jung; Chang, Seong-Hwan; Kim, GonSup; Ryu, Chung Ho; Shin, Sung Chul; Hong, Soon Chan; Choi, Yung Hyun; Jung, Jin-Myung

    2014-01-01

    Background: The extract of Allium cepa Linn is commonly used as adjuvant food for cancer therapy. We assumed that it includes a potential source of anti-cancer properties. Methods: We investigated anti-cancer effects of polyphenols extracted from lyophilized A. cepa Linn (PEAL) in AGS human cancer cells. Results: PEAL inhibited cell growth in a dose-dependent manner. It was related to caspase-dependent apoptosis. We confirmed this finding with annexin V staining. PEAL up-regulated p53 expression, and subsequent Bax induction, down regulated Bcl-2 protein, anti-apoptotic protein. In addition, PEAL suppressed Akt activity and PEAL-induced apoptosis were significantly accentuated with Akt inhibitor (LY294002). Conclusions: Our data suggested that PEAL induce caspase-dependent apoptosis through mitochondrial pathway by up-regulating p53 protein, and subsequent Bax protein as well as by modulating Bcl-2 protein, and that PEAL induces caspase-dependent apoptosis at least in part through the inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. This study provides evidence that PEAL might be useful for the treatment of cancer. PMID:25337568

  8. Selective inhibition of PTEN preserves ischaemic post-conditioning cardioprotection in STZ-induced Type 1 diabetic rats: role of the PI3K/Akt and JAK2/STAT3 pathways.

    PubMed

    Xue, Rui; Lei, Shaoqing; Xia, Zhong-yuan; Wu, Yang; Meng, Qingtao; Zhan, Liying; Su, Wating; Liu, Huimin; Xu, Jinjin; Liu, Zhenzhen; Zhou, Bin; Xia, Zhengyuan

    2016-03-01

    Patients with diabetes are vulnerable to MI/R (myocardial ischaemia/reperfusion) injury, but are not responsive to IPostC (ischaemic post-conditioning) which activates PI3K (phosphoinositide 3-kinase)/Akt (also known as PKB or protein kinase B) and JAK2 (Janus kinase 2)/STAT3 (signal transducer and activator of transcription 3) pathways to confer cardioprotection. We hypothesized that increased cardiac PTEN (phosphatase and tensin homologue deleted on chromosome 10), a major negative regulator of PI3K/Akt, is responsible for the loss of diabetic heart sensitivity to IPostC cardioprotecton. In STZ (streptozotocin)-induced Type 1 diabetic rats subjected to MI/R (30 min coronary occlusion and 120 min reperfusion), the post-ischaemic myocardial infarct size, CK-MB (creatine kinase-MB) and 15-F2t-isoprostane release, as well as cardiac PTEN expression were significantly higher than those in non-diabetic controls, concomitant with more severe cardiac dysfunction and lower cardiac Akt, STAT3 and GSK-3β (glycogen synthase kinase 3β) phosphorylation. IPostC significantly attenuated post-ischaemic infarct size, decreased PTEN expression and further increased Akt, STAT3 and GSK-3β phosphorylation in non-diabetic, but not in diabetic rats. Application of the PTEN inhibitor BpV (bisperoxovanadium) (1.0 mg/kg) restored IPostC cardioprotection in diabetic rats. HPostC (hypoxic post-conditioning) in combination with PTEN gene knockdown, but not HPostC alone, significantly reduced H/R (hypoxia/reoxygenation) injury in cardiac H9c2 cells exposed to high glucose as was evident from reduced apoptotic cell death and JC-1 monomer in cells, accompanied by increased phosphorylation of Akt, STAT3 and GSK-3β. PTEN inhibition/gene knockdown mediated restoration of IPostC/HPostC cardioprotection was completely reversed by the PI3K inhibitor wortmannin, and partially reversed by the JAK2 inhibitor AG490. Increased cardiac PTEN, by impairing PI3K/Akt and JAK2/STAT3 pathways, is a major

  9. Helicobacter pylori neutrophil-activating protein induces release of histamine and interleukin-6 through G protein-mediated MAPKs and PI3K/Akt pathways in HMC-1 cells.

    PubMed

    Tsai, Chung-Che; Kuo, Ting-Yu; Hong, Zhi-Wei; Yeh, Ying-Chieh; Shih, Kuo-Shun; Du, Shin-Yi; Fu, Hua-Wen

    2015-01-01

    Helicobacter pylori neutrophil-activating protein (HP-NAP) activates several innate leukocytes including neutrophils, monocytes, and mast cells. It has been reported that HP-NAP induces degranulation and interleukin-6 (IL-6) secretion of rat peritoneal mast cells. However, the molecular mechanism is not very clear. Here, we show that HP-NAP activates human mast cell line-1 (HMC-1) cells to secrete histamine and IL-6. The secretion depends on pertussis toxin (PTX)-sensitive heterotrimeric G proteins but not on Toll-like receptor 2. Moreover, HP-NAP induces PTX-sensitive G protein-mediated activation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38-mitogen-activated protein kinase (p38 MAPK), and Akt in HMC-1 cells. Inhibition of ERK1/2, p38 MAPK, or phosphatidylinositol 3-kinase (PI3K) suppresses HP-NAP-induced release of histamine and IL-6 from HMC-1 cells. Thus, the activation of HMC-1 cells by HP-NAP is through Gi-linked G protein-coupled receptor-mediated MAPKs and PI3K/Akt pathways.

  10. Glycoprotein nonmetastatic melanoma protein B extracellular fragment shows neuroprotective effects and activates the PI3K/Akt and MEK/ERK pathways via the Na+/K+-ATPase

    PubMed Central

    Ono, Yoko; Tsuruma, Kazuhiro; Takata, Masafumi; Shimazawa, Masamitsu; Hara, Hideaki

    2016-01-01

    Glycoprotein nonmetastatic melanoma protein B (GPNMB) plays important roles in various types of cancer and amyotrophic lateral sclerosis (ALS). The details of GPNMB function and its interacting protein have not been clarified. Therefore, to identify GPNMB binding partners on the cell membrane, we used membrane protein library/BLOTCHIP-MS technology, which enables us to analyze all cell membrane proteins as binding partners of the GPNMB extracellular fragment. As a result of a comprehensive search, we identified the alpha subunits of Na+/K+-ATPase (NKA) as a possible binding partner. We confirmed the interaction between the GPNMB extracellular fragment and NKA by immunoprecipitation and immunostaining in NSC-34 cells. Indeed, endogenous GPNMB extracellular fragment bound to and colocalized with NKA alpha subunits. Furthermore, exogenous GPNMB extracellular fragment, i.e., human recombinant GPNMB, also bound to and colocalized with NKA alpha subunits. Additionally, we found that the GPNMB extracellular fragment had neuroprotective effects and activated the phosphoinositide 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK pathways via NKA. These findings indicated that NKA may act as a novel “receptor” for the GPNMB extracellular fragment, offering additional molecular targets for the treatment of GPNMB-related diseases, including various types of cancer and ALS. PMID:26988030

  11. Activation of the PI3K-Akt pathway by human T cell leukemia virus type 1 (HTLV-1) oncoprotein Tax increases Bcl3 expression, which is associated with enhanced growth of HTLV-1-infected T cells

    SciTech Connect

    Saito, Kousuke; Saito, Mineki; Taniura, Naoko; Okuwa, Takako; Ohara, Yoshiro

    2010-08-01

    Bcl3 is a member of the I{kappa}B family that regulates genes involved in cell proliferation and apoptosis. Recent reports indicated that Bcl3 is overexpressed in HTLV-1-infected T cells via Tax-mediated transactivation, and acts as a negative regulator of viral transcription. However, the role of Bcl3 in cellular signal transduction and the growth of HTLV-1-infected T cells have not been reported. In this study, we showed that the knockdown of Bcl3 by short hairpin RNA inhibited the growth of HTLV-1-infected T cells. Although phosphatidylinositol-3 kinase (PI3K) inhibitor reduced Bcl3 expression, inactivation of glycogen synthase kinase 3 (GSK3), an effector kinase of the PI3K/Akt signaling pathway, restored Bcl3 expression in Tax-negative but not in Tax-positive T cells. Our results indicate that the overexpression of Bcl3 in HTLV-1-infected T cells is regulated not only by transcriptional but also by post-transcriptional mechanisms, and is involved in overgrowth of HTLV-1-infected T cells.

  12. Ephedrine hydrochloride inhibits PGN-induced inflammatory responses by promoting IL-10 production and decreasing proinflammatory cytokine secretion via the PI3K/Akt/GSK3β pathway.

    PubMed

    Zheng, Yuejuan; Yang, Yang; Li, Yuhu; Xu, Limin; Wang, Yi; Guo, Ziyi; Song, Haiyan; Yang, Muyi; Luo, Beier; Zheng, Aoxiang; Li, Ping; Zhang, Yan; Ji, Guang; Yu, Yizhi

    2013-07-01

    Approaches for controlling inflammatory responses and reducing the mortality rate of septic patients remain clinically ineffective; new drugs need to be identified that can induce anti-inflammatory responses. Ephedrine hydrochloride (EH) is a compound that is widely used in cardiovascular diseases, especially to treat hypotension caused by either anesthesia or overdose of antihypertensive drugs. In this study, we reported that EH also plays an important role in the control of the inflammatory response. EH increased IL-10 and decreased proinflammatory cytokine (IL-6, tumor-necrosis factor (TNF)-α, IL-12 and IL-1β) expression in primary peritoneal macrophages and Raw264.7 cells treated with peptidoglycan (PGN), a Gram-positive cell wall component. The anti-inflammatory role of EH was also demonstrated in an experimental mouse model of peritonitis induced by intraperitoneal PGN injection. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway was found to be responsible for the EH-mediated increase in IL-10 production and decrease in IL-6 expression. Therefore, our results illustrated that EH can help maintain immune equilibrium and diminish host damage by balancing the production of pro- and anti-inflammatory cytokines after PGN challenge. EH may be a new potential anti-inflammatory drug that can be useful for treating severe invasive Gram-positive bacterial infection.

  13. DNA Hypermethylation of CREB3L1 and Bcl-2 Associated with the Mitochondrial-Mediated Apoptosis via PI3K/Akt Pathway in Human BEAS-2B Cells Exposure to Silica Nanoparticles

    PubMed Central

    Zou, Yang; Li, Qiuling; Jiang, Lizhen; Guo, Caixia; Li, Yanbo; Yu, Yang; Li, Yang; Duan, Junchao; Sun, Zhiwei

    2016-01-01

    The toxic effects of silica nanoparticles (SiNPs) are raising concerns due to its widely applications in biomedicine. However, current information about the epigenetic toxicity of SiNPs is insufficient. In this study, the epigenetic regulation of low-dose exposure to SiNPs was evaluated in human bronchial epithelial BEAS-2B cells over 30 passages. Cell viability was decreased in a dose- and passage-dependent manner. The apoptotic rate, the expression of caspase-9 and caspase-3, were significantly increased induced by SiNPs. HumanMethylation450 BeadChip analysis identified that the PI3K/Akt as the primary apoptosis-related pathway among the 25 significant altered processes. The differentially methylated sites of PI3K/Akt pathway involved 32 differential genes promoters, in which the CREB3L1 and Bcl-2 were significant hypermethylated. The methyltransferase inhibitor, 5-aza, further verified that the DNA hypermethylation status of CREB3L1 and Bcl-2 were associated with downregulation of their mRNA levels. In addition, mitochondrial-mediated apoptosis was triggered by SiNPs via the downregulation of PI3K/Akt/CREB/Bcl-2 signaling pathway. Our findings suggest that long-term low-dose exposure to SiNPs could lead to epigenetic alterations. PMID:27362941

  14. 3,5,3'-triiodothyronine (T3) stimulates cell proliferation through the activation of the PI3K/Akt pathway and reactive oxygen species (ROS) production in chick embryo hepatocytes.

    PubMed

    Gnocchi, Davide; Leoni, Silvia; Incerpi, Sandra; Bruscalupi, Giovannella

    2012-05-01

    Thyroid hormones (THs) have a wide variety of essential roles in vertebrates, ranging from the regulation of key metabolic processes to cell proliferation and apoptosis. The classical mechanism of action of THs is genomic; 3,5,3'-triiodothyronine (T3) binds to specific nuclear receptors (TRs) and modifies the expression of specific genes. Recently, a new category of mechanisms, termed nongenomic, has been discovered for T3. These mechanisms include, among others, the rapid activation of signal transduction pathways, such as PI3K/Akt and MAPK, which eventually lead to cell proliferation. These effects are mediated in some cell types by a plasma membrane receptor, identified as integrin αvβ3, and in other cell types by cytoplasmic TRβ1. The aim of this work was to analyze the effect of T3 on the cell growth of chick embryo hepatocytes at two different stages of development, 14 and 19 days, and to determine the activation of the signal transduction pathways, focusing on the potential involvement of a plasma membrane receptor and the possible participation of PI3K/Akt and reactive oxygen species (ROS). Our results clearly show that T3 stimulates cell proliferation at both stages of development through the activation of the PI3K/Akt pathway and the production of small amounts of ROS, which operate as effective second messengers. Moreover, we prove that these effects are not initiated at the plasma membrane receptor for T3.

  15. Reactive Oxygen Species via Redox Signaling to PI3K/AKT Pathway Contribute to the Malignant Growth of 4-Hydroxy Estradiol-Transformed Mammary Epithelial Cells

    PubMed Central

    Okoh, Victor O.; Felty, Quentin; Parkash, Jai; Poppiti, Robert; Roy, Deodutta

    2013-01-01

    The purpose of this study was to investigate the effects of 17-β-estradiol (E2)-induced reactive oxygen species (ROS) on the induction of mammary tumorigenesis. We found that ROS-induced by repeated exposures to 4-hydroxy-estradiol (4-OH-E2), a predominant catechol metabolite of E2, caused transformation of normal human mammary epithelial MCF-10A cells with malignant growth in nude mice. This was evident from inhibition of estrogen-induced breast tumor formation in the xenograft model by both overexpression of catalase as well as by co-treatment with Ebselen. To understand how 4-OH-E2 induces this malignant phenotype through ROS, we investigated the effects of 4-OH-E2 on redox-sensitive signal transduction pathways. During the malignant transformation process we observed that 4-OH-E2 treatment increased AKT phosphorylation through PI3K activation. The PI3K-mediated phosphorylation of AKT in 4-OH-E2-treated cells was inhibited by ROS modifiers as well as by silencing of AKT expression. RNA interference of AKT markedly inhibited 4-OH-E2-induced in vitro tumor formation. The expression of cell cycle genes, cdc2, PRC1 and PCNA and one of transcription factors that control the expression of these genes – nuclear respiratory factor-1 (NRF-1) was significantly up-regulated during the 4-OH-E2-mediated malignant transformation process. The increased expression of these genes was inhibited by ROS modifiers as well as by silencing of AKT expression. These results indicate that 4-OH-E2-induced cell transformation may be mediated, in part, through redox-sensitive AKT signal transduction pathways by up-regulating the expression of cell cycle genes cdc2, PRC1 and PCNA, and the transcription factor – NRF-1. In summary, our study has demonstrated that: (i) 4-OH-E2 is one of the main estrogen metabolites that induce mammary tumorigenesis and (ii) ROS-mediated signaling leading to the activation of PI3K/AKT pathway plays an important role in the generation of 4-OH-E2-induced

  16. MiR-206 inhibits HGF-induced epithelial-mesenchymal transition and angiogenesis in non-small cell lung cancer via c-Met /PI3k/Akt/mTOR pathway

    PubMed Central

    Wu, Yu-quan; Chen, Jun; Wang, Jian; Tang, Xia-li; Mou, Hao; Hu, Hui-zhen; Song, Jia; Yan, Jie; Wu, Li-jun; Chen, Jianyan; Wang, Zhiwei

    2016-01-01

    MiR-206 is low expression in lung cancers and associated with cancer metastasis. However, the roles of miR-206 in epithelial-mesenchymal transition (EMT) and angiogenesis in lung cancer remain unknown. In this study, we find that hepatocyte growth factor (HGF) induces EMT, invasion and migration in A549 and 95D lung cancer cells, and these processes could be markedly inhibited by miR-206 overexpression. Moreover, we demonstrate that miR-206 directly targets c-Met and inhibits its downstream PI3k/Akt/mTOR signaling pathway. In contrast, miR-206 inhibitors promote the expression of c-Met and activate the PI3k/Akt/mTOR signaling, and this effect could be attenuated by the PI3K inhibitor. Moreover, c-Met overexpression assay further confirms the significant inhibitory effect of miR-206 on HGF-induced EMT, cell migration and invasion. Notably, we also find that miR-206 effectively inhibits HGF-induced tube formation and migration of human umbilical vein endothelial cells (HUVECs), and the mechanism is also related to inhibition of PI3k/Akt/mTOR signaling. Finally, we reveal the inhibitory effect of miR-206 on EMT and angiogenesis in xenograft tumor mice model. Taken together, miR-206 inhibits HGF-induced EMT and angiogenesis in lung cancer by suppressing c-Met/PI3k/Akt/mTOR signaling. Therefore, miR-206 might be a potential target for the therapeutic strategy against EMT and angiogenesis of lung cancer. PMID:26919096

  17. TOP 1 and 2, polysaccharides from Taraxacum officinale, inhibit NFκB-mediated inflammation and accelerate Nrf2-induced antioxidative potential through the modulation of PI3K-Akt signaling pathway in RAW 264.7 cells.

    PubMed

    Park, Chung Mu; Cho, Chung Won; Song, Young Sun

    2014-04-01

    Anti-inflammatory and anti-oxidative activities of polysaccharides from Taraxacum officinale (TOP 1 and 2) were analyzed in RAW 264.7 cells. First, lipopolysaccharide (LPS) was applied to identify anti-inflammatory activity of TOPs, which reduced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α. TOPs treatment inhibited phosphorylation of inflammatory transcription factor, nuclear factor (NF)κB, and its upstream signaling molecule, PI3K/Akt. Second, cytoprotective potential of TOPs against oxidative stress was investigated via heme oxygenase (HO)-1 induction. HO-1, one of phase II enzymes shows antioxidative activity, was potently induced by TOPs treatment, which was in accordance with the nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2). In addition, TOPs treatment phosphorylated PI3K/Akt with slight activation of c-Jun NH2-terminal kinase (JNK). TOPs-mediated HO-1 induction protected macrophage cells from oxidative stress-induced cell death, which was confirmed by SnPP and CoPP (HO-1 inhibitor and inducer, respectively). Consequently, TOPs potently inhibited NFκB-mediated inflammation and accelerated Nrf2-mediated antioxidative potential through the modulation of PI3K/Akt pathway, which would contribute to their promising strategy for novel anti-inflammatory and anti-oxidative agents.

  18. PI3K/AKT signaling pathway plays a role in enhancement of eNOS activity by recombinant human angiotensin converting enzyme 2 in human umbilical vein endothelial cells

    PubMed Central

    Zhang, Yan; Wang, Shi-Jie; Han, Zhen-Hua; Li, Yong-Qin; Xue, Jia-Hong; Gao, Deng-Feng; Wu, Xiao-San; Wang, Cong-Xia

    2014-01-01

    The aim of this study was to investigate the effect of PI3K/AKT signaling pathway in the activity of recombinant human angiotensin converting enzyme 2 (rhACE2) promoted the activity of endothelial nitric oxide synthase (eNOS). The human umbilical vein endothelial cells (HUVEC) were cultured in vitro. Then treated with Ang II (1×10-6 mol/L) for 24 h. The rhACE2 (100 μmol/L) was added and incubated for 5, 10, 15, 30, 60 min respectively which was based on Ang II intervention. The effect of rhACE2 on phosphorylation eNOS level was also observed in the presence of LY294002 (10 μmol/L) (PI3K/AKT inhibitors). Griess reagent method was applied to measure NO contents in cell culture supernatant, RT-PCR to detect the expression of eNOSmRNA in HUVEC, and Western blot to detect the expression of eNOS and phosphorylated eNOS. In Ang II intervention group, NO contents were significantly lower than control group (P < 0.05). Through rhACE2 treatment, the NO contents in cell culture medium and the expression level of phosphorylated eNOS were significantly higher than in Ang II intervention group (P < 0.05), but eNOSmRNA and non-phosphorylated eNOS protein expression level showed no significant difference (P > 0.05). After HUVEC was intervened by PI3K/AKT pathway inhibitor LY294002, the expression level of phosphorylated eNOS was significantly lower than that in the rhACE2 30 min treatment group (P < 0.05). rhACE2 may reduce the activity of Ang II inhibited endothelial cell eNOS, which can be blocked by PI3K/AKT pathway inhibitor LY294002, suggesting PI3K/AKT signaling pathway plays an important role in rhACE2’s promotion of the activity of endothelial cell eNOS. PMID:25550859

  19. Do airborne biogenic chemicals interact with the PI3K/Akt/mTOR cell signalling pathway to benefit human health and wellbeing in rural and coastal environments?

    PubMed

    Moore, Michael N

    2015-07-01

    Living and taking recreation in rural and coastal environments promote health and wellbeing, although the causal factors involved are unclear. It has been proposed that such environments provide a counter to the stresses of everyday living, leading to enhanced mental and physical health. Living in natural environments will result in airborne exposure to a wide range of biogenic chemicals through inhalation and ingestion of airborne microbiota and particles. The "biogenics" hypothesis formulated here is that regular exposure to low concentrations of mixtures of natural compounds and toxins in natural environments confers pleiotropic health benefits by inhibiting the activities of interconnected cell signalling systems, particularly PI3K/Akt/mTORC1. When overactive, Akt and mTOR (mTORC1) can lead to many pathological processes including cancers, diabetes, inflammation, immunosuppression, and neurodegenerative diseases. There is a substantial body of evidence that many natural products (i.e., from bacteria, algae, fungi and higher plants) inhibit the activities of these protein kinases. Other mTOR-related interconnected metabolic control "switches" (e.g., PTEN & NF-κB), autophagy and other cytoprotective processes are also affected by natural products. The "biogenics" hypothesis formulated here is that regular intermittent exposure to a mixture of airborne biogenic compounds in natural environments confers pleiotropic health benefits by inhibiting activities of the highly interconnected PI3K/Akt/mTORC1 system. It is proposed that future experimental exposures to biogenic aerosols in animal models coupled with epidemiology, should target the activities of the various kinases in the PI3K/Akt/mTORC1 systems and related physiological processes for selected urban, rural and coastal populations in order to test this hypothesis.

  20. Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro

    SciTech Connect

    Wang, Tao Fang; Wang, Heng; Peng, Ai Fen; Luo, Qing Feng; Liu, Zhi Li; Zhou, Rong Ping; Gao, Song; Zhou, Yang; Chen, Wen Zhao

    2013-10-18

    Highlights: •We investigate the relationship between FASN and HER2 or p-HER2 by IHC in OS tissues. •We construct FASN-specific RNAi plasmid. •Inhibiting FASN down-regulates HER2/PI3K/AKT cell signaling in U-2 OS. •Inhibiting FASN blocks U-2 OS cell invasion and migration. -- Abstract: FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the “HER2/PI3K/AKT” axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.

  1. Early single Aspirin-triggered Lipoxin blocked morphine anti-nociception tolerance through inhibiting NALP1 inflammasome: Involvement of PI3k/Akt signaling pathway.

    PubMed

    Tian, Yu; Liu, Ming; Mao-Ying, Qi-Liang; Liu, Huan; Wang, Zhi-Fu; Zhang, Meng-Ting; Wang, Jun; Li, Qian; Liu, Shen-Bin; Mi, Wen-Li; Ma, Hong-Jian; Wu, Gen-Cheng; Wang, Yan-Qing

    2015-11-01

    Clinical usage of opioids in pain relief is dampened by analgesic tolerance after chronic exposure, which is related to opioid-associated neuroinflammation. In the current study, which is based on a chronic morphine tolerance rat model and sustained morphine treatment on primary neuron culture, it was observed that Akt phosphorylation, cleaved-Caspase-1-dependent NALP1 inflammasome activation and IL-1β maturation in spinal cord neurons were significantly enhanced by morphine. Moreover, treatment with LY294002, a specific inhibitor of PI3k/Akt signaling, significantly reduced Caspase-1 cleavage, NALP1 inflammasome activation and attenuated morphine tolerance. Tail-flick tests demonstrated that pharmacological inhibition on Caspase-1 activation or antagonizing IL-1β dramatically blocked the development of morphine tolerance. The administration of an exogenous analogue of lipoxin, Aspirin-triggered Lipoxin (ATL), caused a decline in Caspase-1 cleavage, inflammasome activation and mature IL-1β production and thus attenuated the development of morphine tolerance by inhibiting upstream Akt phosphorylation. Additionally, treatment with DAMGO, a selective μ-opioid receptor peptide, significantly induced Akt phosphorylation, Caspase-1 cleavage and anti-nociception tolerance, all of which were attenuated by ATL treatment. Taken together, the present study revealed the involvement of spinal NALP1 inflammasome activation in the development of morphine tolerance and the role of the μ-receptor/PI3k-Akt signaling/NALP1 inflammasome cascade in this process. By inhibiting this signaling cascade, ATL blocked the development of morphine tolerance. PMID:26162710

  2. Early single Aspirin-triggered Lipoxin blocked morphine anti-nociception tolerance through inhibiting NALP1 inflammasome: Involvement of PI3k/Akt signaling pathway.

    PubMed

    Tian, Yu; Liu, Ming; Mao-Ying, Qi-Liang; Liu, Huan; Wang, Zhi-Fu; Zhang, Meng-Ting; Wang, Jun; Li, Qian; Liu, Shen-Bin; Mi, Wen-Li; Ma, Hong-Jian; Wu, Gen-Cheng; Wang, Yan-Qing

    2015-11-01

    Clinical usage of opioids in pain relief is dampened by analgesic tolerance after chronic exposure, which is related to opioid-associated neuroinflammation. In the current study, which is based on a chronic morphine tolerance rat model and sustained morphine treatment on primary neuron culture, it was observed that Akt phosphorylation, cleaved-Caspase-1-dependent NALP1 inflammasome activation and IL-1β maturation in spinal cord neurons were significantly enhanced by morphine. Moreover, treatment with LY294002, a specific inhibitor of PI3k/Akt signaling, significantly reduced Caspase-1 cleavage, NALP1 inflammasome activation and attenuated morphine tolerance. Tail-flick tests demonstrated that pharmacological inhibition on Caspase-1 activation or antagonizing IL-1β dramatically blocked the development of morphine tolerance. The administration of an exogenous analogue of lipoxin, Aspirin-triggered Lipoxin (ATL), caused a decline in Caspase-1 cleavage, inflammasome activation and mature IL-1β production and thus attenuated the development of morphine tolerance by inhibiting upstream Akt phosphorylation. Additionally, treatment with DAMGO, a selective μ-opioid receptor peptide, significantly induced Akt phosphorylation, Caspase-1 cleavage and anti-nociception tolerance, all of which were attenuated by ATL treatment. Taken together, the present study revealed the involvement of spinal NALP1 inflammasome activation in the development of morphine tolerance and the role of the μ-receptor/PI3k-Akt signaling/NALP1 inflammasome cascade in this process. By inhibiting this signaling cascade, ATL blocked the development of morphine tolerance.

  3. Epidermal growth factor receptor regulates MT1-MMP and MMP-2 synthesis in SiHa cells via both PI3-K/AKT and MAPK/ERK pathways.

    PubMed

    Zhang, Zongfeng; Song, Tiefang; Jin, Yinglan; Pan, Jiaqi; Zhang, Liying; Wang, Lingdi; Li, Peiling

    2009-08-01

    Matrix metalloproteinase 2 (MMP-2) and membrane type 1 matrix metalloproteinase (MT1-MMP) have been identified as important participants in tumor invasion, metastasis, and angiogenesis. Membrane type 1 matrix metalloproteinase has also been recognized as a major activator of MMP-2. The purpose of this study was to investigate epidermal growth factor (EGF) mediating signal pathways in the regulation of MMP-2 and MT1-MMP in SiHa cells, a cervical cancer cell line. We showed here that EGF induced the expression of MT1-MMP and inhibited the expression of MMP-2 at both the mRNA and protein levels. Membrane type 1 matrix metalloproteinase induction was blocked by mitogen-activated protein kinase or extracellular signal-regulated kinase inhibitors PD98059 and U0126 but not by phosphatidylinositol-3 kinase (PI3-K) inhibitors LY294002 and wortmannin. Interestingly, the mitogen-activated protein kinase or extracellular signal-regulated kinase inhibitors PD98059 and U0126 actually increased MMP-2 mRNA and protein synthesis, whereas the PI3-K inhibitors LY294002 and wortmannin further suppressed the expression of MMP-2. Our results suggest that EGF receptor up-regulated the expression of MT1-MMP and down-regulated the synthesis of MMP-2 through the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway while concomitantly transmitting a mild positive regulatory signal to the expression of MMP-2 via the PI3-K/AKT pathway in SiHa cells. Furthermore, we found that EGF elevated the activity of MMP-2 in culture media.

  4. Simvastatin-induced breast cancer cell death and deactivation of PI3K/Akt and MAPK/ERK signalling are reversed by metabolic products of the mevalonate pathway

    PubMed Central

    Wang, Tingting; Seah, Serena; Loh, Xinyi; Chan, Ching-Wan; Hartman, Mikael; Goh, Boon-Cher; Lee, Soo-Chin

    2016-01-01

    Statins purportedly exert anti-tumoral effects on breast cancer. However, the biologic mechanisms for these actions are not fully elucidated. The aims of this study were 1) to explore the effects of simvastatin on apoptosis, proliferation as well as PI3K/Akt/mTOR and MAPK/ERK pathway in a window-of-opportunity breast cancer trial; 2) to further confirm findings from the clinical trial by functional studies; 3) to explore the regulatory role of mevalonate pathway on the anti-tumoral effects of simvastatin. In clinical samples, simvastatin led to increase in cleaved caspase-3 (p = 0.002) and decreased trend for Ki67 (p = 0.245). Simvastatin markedly suppressed PI3K/Akt/mTOR signalling by activating PTEN (p = 0.005) and by dephosphorylating Akt (p = 0.002) and S6RP (p = 0.033); it also inhibited MAPK/ERK pathway by dephosphorylating c-Raf (p = 0.018) and ERK1/2 (p = 0.002). In ER-positive (MCF-7, T47D) and ER-negative (MDA-MB-231, BT-549) breast cancer cells, simvastatin treatment consistently induced apoptosis and inhibited proliferation by deregulating caspase cascades and cell cycle proteins in a dose dependent manner. Concordantly, simvastatin strongly suppressed PI3K/Akt/mTOR pathway by enhancing PTEN expression and by further sequentially dephosphorylating downstream cascades including Akt, mTOR, p70S6K, S6RP and 4E-BP1. Furthermore, simvastatin significantly inhibited MAPK/ERK pathway by dephosphorylating sequential cascades such as c-Raf, MEK1/2 and ERK1/2. These simvastatin anti-tumoral effects were reversed by metabolic products of the mevalonate pathway, including mevalonate, farnesyl pyrophosphate and geranylgeranyl pyrophosphate. These findings shed light on the biological and potential anti-tumoral effects of simvastatin in breast cancer. PMID:26565813

  5. MiR-126 regulates proliferation and invasion in the bladder cancer BLS cell line by targeting the PIK3R2-mediated PI3K/Akt signaling pathway