101
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He S, Li Q, Jiang X, Lu X, Feng F, Qu W, Chen Y, Sun H. Design of Small Molecule Autophagy Modulators: A Promising Druggable Strategy. J Med Chem 2017; 61:4656-4687. [PMID: 29211480 DOI: 10.1021/acs.jmedchem.7b01019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Autophagy is a lysosome-dependent mechanism of intracellular degradation for maintaining cellular homeostasis. Dysregulation of autophagy has been verified to be closely linked to a number of human diseases. Consequently, targeting autophagy has been highlighted as a novel therapeutic strategy for clinical utility. Mounting efforts have been done in recent years to elucidate the mechanisms of autophagy regulation and to identify potential modulators of autophagy. However, most of the compounds target complex and multifaceted pathway and proteins, which may limit the evaluation of therapeutic value and in depth studies as chemical tools. Therefore, the development of specific and active autophagy modulators becomes most desirable. Here, we briefly review the regulation of autophagy and then summarize the recent development of small molecules targeting the core autophagic machinery. Finally, we put forward our viewpoints on the current problems, with the aim to provide reference for future drug discovery and potential therapeutic perspectives on novel, potent, selective autophagy modulators.
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Affiliation(s)
- Siyu He
- Department of Medicinal Chemistry , China Pharmaceutical University , Nanjing 210009 , China
| | - Qi Li
- Department of Medicinal Chemistry , China Pharmaceutical University , Nanjing 210009 , China
| | - Xueyang Jiang
- Key Laboratory of Biomedical Functional Materials, School of Science , China Pharmaceutical University , Nanjing 211198 , China
| | - Xin Lu
- Department of Medicinal Chemistry , China Pharmaceutical University , Nanjing 210009 , China
| | - Feng Feng
- Key Laboratory of Biomedical Functional Materials, School of Science , China Pharmaceutical University , Nanjing 211198 , China
| | - Wei Qu
- Key Laboratory of Biomedical Functional Materials, School of Science , China Pharmaceutical University , Nanjing 211198 , China
| | - Yao Chen
- School of Pharmacy , Nanjing University of Chinese Medicine , Nanjing , 210023 , China
| | - Haopeng Sun
- Department of Medicinal Chemistry , China Pharmaceutical University , Nanjing 210009 , China
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102
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Invitro Evaluation of Torin2 and 2, 6-Dihydroxyacetophenone in Colorectal Cancer Therapy. Pathol Oncol Res 2017; 25:301-309. [DOI: 10.1007/s12253-017-0347-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 10/20/2017] [Indexed: 01/11/2023]
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103
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Luo J, Pi G, Xiao H, Ye Y, Li Q, Zhao L, Huang H, Luo H, Zhang Q, Wang D, Wang G. Torin2 enhances the radiosensitivity of MCF‑7 breast cancer cells by downregulating the mTOR signaling pathway and ATM phosphorylation. Mol Med Rep 2017; 17:366-373. [PMID: 29115478 DOI: 10.3892/mmr.2017.7848] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 08/23/2017] [Indexed: 11/06/2022] Open
Abstract
Radiotherapy has an important role in the comprehensive treatment of breast cancer. However, the clinical outcome of adjuvant radiotherapy may be limited due to intrinsic radioresistance, it is necessary to explore efficient radiosensitization methods that improve the clinical outcome of patients undergoing radiotherapy. The present study aimed to investigate whether the novel mechanistic target of rapamycin (mTOR) inhibitor Torin2 enhances the radiosensitivity of MCF‑7 breast cancer cells. A Cell Counting Kit‑8 (CCK‑8) assay was performed to measure the effect of Torin2 on cell proliferation, while clonogenic assays were employed to determine the effect of Torin2 in combination with radiation on the proliferation of MCF‑7 cells. The effect of Torin2 and/or radiation on the cell cycle was analyzed using flow cytometry. Furthermore, the protein expression of components of the phosphatidylinositol 3‑kinase/Akt/mTOR pathway, and the expression of proteins involved in DNA damage repair, was measured by western blot analysis. The results demonstrated that Torin2 exhibited a higher potency in MCF‑7 cells, while MDA‑MB‑231 cells were less sensitive to Torin2. Compared with irradiation alone, pretreatment with 20 nM Torin2 followed by irradiation resulted in an increased level of γ‑H2A histone family member X. Radiation induced the activation of the Akt/mTOR signaling pathway and upregulated the expression of phosphorylated (p)‑Akt473 and p‑eukaryotic translation initiation factor 4E binding protein 1 (4EBP1)37/46. Notably, pretreatment with Torin2 attenuated the radiation‑induced activation of the Akt/mTOR signaling pathway. In addition, Torin2 partially blocked the repair of double‑strand breaks induced by radiation by reducing the activation of ataxia telangiectasia‑mutated, and sensitized MCF‑7 cells to radiation. In conclusion, administration of Torin2 prior to irradiation enhanced the radiotherapeutic effect on breast cancer cells in vitro, and these results may provide a foundation for the rational use of combined therapy with irradiation and Torin2 for breast cancer in clinical practice.
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Affiliation(s)
- Jia Luo
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Guocheng Pi
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - He Xiao
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Yunfei Ye
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Qing Li
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Lianhua Zhao
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Huan Huang
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Hong Luo
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Qin Zhang
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Dong Wang
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Ge Wang
- Cancer Center of Daping Hospital and The Research Institute of Surgery, The Third Military Medical University, Chongqing 400042, P.R. China
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104
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Khan N, Jajeh F, Khan MI, Mukhtar E, Shabana SM, Mukhtar H. Sestrin-3 modulation is essential for therapeutic efficacy of cucurbitacin B in lung cancer cells. Carcinogenesis 2017; 38:184-195. [PMID: 27881463 DOI: 10.1093/carcin/bgw124] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 11/22/2016] [Indexed: 12/12/2022] Open
Abstract
Many purified compounds from dietary sources have been investigated for their anticancer activities. The main issue with most agents is their effectiveness at high doses which generally could not be delivered to humans through dietary consumption. Here, we observed that cucurbitacin B, a tetracyclic triterpenoid present in pumpkins, gourds and squashes, exhibits antiproliferative effects on human non-small cell lung cancer (NSCLC) cells at nanomolar concentrations. Treatment with cucurbitacin B (0.2-0.6 μM; 24 h) was found to result in decrease in the viability of EGFR-wild type (A549 and H1792) and EGFR-mutant lung cancer cells (H1650 and H1975) and reduction in cell-colonies but had only minimal effect on normal human bronchial epithelial cells. Treatment with cucurbitacin B also caused inhibition of PI3K/mTOR and signal transducer and activator of transcription (STAT)-3 signaling along with simultaneous activation of AMPKα levels in both EGFR-wild type and EGFR-mutant lung cancer cells. Cucurbitacin B caused specific increase in the protein and mRNA expression of sestrin-3 in EGFR-mutant lung cancer cells, but not in EGFR-wild type cells. Treatment with cucurbitacin B to sestrin-3 siRNA treated EGFR-mutant cells further amplified the decrease in cell-viability and caused more sustained G2-phase cell cycle arrest, suggesting that these effects are mediated partly through sestrin-3. We also found that sestrin-3 has a role in the induction of apoptosis by cucurbitacin B in both EGFR-wild type and EGFR-mutant lung cancer cells. These findings suggest novel mechanism by the modulation of sestrin-3 for the action of cucurbitacin B and suggest that it could be developed as an agent for therapy of NSCLC.
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Affiliation(s)
- Naghma Khan
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA and
| | - Farah Jajeh
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA and
| | - Mohammad Imran Khan
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA and
| | - Eiman Mukhtar
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA and
| | - Sameh M Shabana
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA and.,Department of Zoology, Faculty of Science, Mansoura University, Egypt
| | - Hasan Mukhtar
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA and
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Hassett MR, Sternberg AR, Roepe PD. Inhibition of Human Class I vs Class III Phosphatidylinositol 3′-Kinases. Biochemistry 2017; 56:4326-4334. [DOI: 10.1021/acs.biochem.7b00413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Matthew R. Hassett
- Department of Chemistry and Department of Biochemistry & Cellular & Molecular Biology, Georgetown University, 37th and O Streets NW, Washington, D.C. 20057, United States
| | - Anna R. Sternberg
- Department of Chemistry and Department of Biochemistry & Cellular & Molecular Biology, Georgetown University, 37th and O Streets NW, Washington, D.C. 20057, United States
| | - Paul D. Roepe
- Department of Chemistry and Department of Biochemistry & Cellular & Molecular Biology, Georgetown University, 37th and O Streets NW, Washington, D.C. 20057, United States
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106
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Phosphatidylinositol 3 kinase (PI3K) modulates manganese homeostasis and manganese-induced cell signaling in a murine striatal cell line. Neurotoxicology 2017; 64:185-194. [PMID: 28780388 DOI: 10.1016/j.neuro.2017.07.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 07/14/2017] [Accepted: 07/14/2017] [Indexed: 12/22/2022]
Abstract
In a recent study, we found that blocking the protein kinase ataxia telangiectasia mutated (ATM) with the small molecule inhibitor (SMI) KU-55933 can completely abrogate Mn-induced phosphorylation of p53 at serine 15 (p-p53) in human induced pluripotent stem cell (hiPSC)-differentiated striatal neuroprogenitors. However, in the immortalized mouse striatal progenitor cell line STHdhQ7/Q7, a concentration of KU55933 far exceeding its IC50 for ATM was required to inhibit Mn-induced p-p53. This suggested an alternative signaling system redundant with ATM kinase for activating p53 in this cell line- one that was altered by KU55933 at these higher concentrations (i.e. mTORC1, DNApk, PI3K). To test the hypothesis that one or more of these signaling pathways contributed to Mn-induced p-p53, we utilized a set of SMIs (e.g. NU7441 and LY294002) known to block DNApk, PI3K, and mTORC1 at distinct concentrations. We found that the SMIs inhibit Mn-induced p-p53 expression near the expected IC50s for PI3K, versus other known targets. We hypothesized that inhibiting PI3K reduces intracellular Mn and thereby decreases activation of p53 by Mn. Using the cellular fura-2 manganese extraction assay (CFMEA), we determined that KU55933/60019, NU7441, and LY294002 (at concentrations near their IC50s for PI3K) all decrease intracellular Mn (∼50%) after a dual, 24-h Mn and SMI exposure. Many pathways are activated by Mn aside from p-p53, including AKT and mTOR pathways. Thus, we explored the activation of these pathways by Mn in STHdh cells as well as the effects of other pathway inhibitors. p-AKT and p-S6 activation by Mn is almost completely blocked upon addition of NU7441(5μM) or LY294002(7μM), supporting PI3K's upstream role in the AKT/mTOR pathway. We also investigated whether PI3K inhibition blocks Mn uptake in other cell lines. LY294002 exposure did not reduce Mn uptake in ST14A, Neuro2A, HEK293, MEF, or hiPSC-derived neuroprogenitors. Next, we sought to determine whether inhibition of PI3K blocked p53 phosphorylation by directly blocking an unknown PI3K/p53 interaction or indirectly reducing intracellular Mn, decreasing p-p53 expression. In-Cell Western and CFMEA experiments using multiple concentrations of Mn exposures demonstrated that intracellular Mn levels directly correlated with p-p53 expression with or without addition of LY294002. Finally, we examined whether PI3K inhibition was able to block Mn-induced p-p53 activity in hiPSC-derived striatal neuroprogenitors. As expected, LY294002 does not block Mn-induced p-p53 as PI3K inhibition is unable to reduce Mn net uptake in this cell line, suggesting the effect of LY294002 on Mn uptake is relatively specific to the STHdh mouse striatal cell line.
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107
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Osoegawa A, Gills JJ, Kawabata S, Dennis PA. Rapamycin sensitizes cancer cells to growth inhibition by the PARP inhibitor olaparib. Oncotarget 2017; 8:87044-87053. [PMID: 29152062 PMCID: PMC5675614 DOI: 10.18632/oncotarget.19667] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 05/12/2017] [Indexed: 12/20/2022] Open
Abstract
Poly (ADP-ribose) polymerase inhibitors (PARPi) have been developed and tested in a context of combining it with double-stranded (ds) DNA repair defects or inhibitors, as PARP inhibitor impairs single-stranded (ss) DNA break repair, resulting in the activation of the dsDNA break repair machinery. Rapamycin has been widely prescribed for more than a decade and recent studies have revealed that it may inhibit dsDNA break repair. The combination of the PARP inhibitor olaparib and rapamycin synergistically inhibited cell proliferation in non-small cell lung cancer (NSCLC) cells, and even in triple negative breast cancer (TNBC) cells with BRCA1 mutations. Rad51, which forms a polymer on ssDNA upon dsDNA breaks, plays an essential role in homologous recombination. Olaparib induced Rad51 focus formation, while rapamycin successfully inhibited it both in vivo and in vitro, suggesting that this combination worked through the blocking of both ssDNA break repair and dsDNA break repair; hence the cells cannot go through the G2/M checkpoint. The protein level of PARP was a predictive marker for both PAR activity and Rad51 focus formation in this combination. Collectively, these data suggest that this combination could have therapeutic potential in the treatment of cancer with high PARP expression, or in combination with cytotoxic chemotherapy or radiotherapy.
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Affiliation(s)
- Atsushi Osoegawa
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joell J Gills
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Shigeru Kawabata
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Phillip A Dennis
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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108
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Drug Modulators of B Cell Signaling Pathways and Epstein-Barr Virus Lytic Activation. J Virol 2017; 91:JVI.00747-17. [PMID: 28566383 DOI: 10.1128/jvi.00747-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 05/24/2017] [Indexed: 11/20/2022] Open
Abstract
Epstein-Barr virus (EBV) is a ubiquitous human gammaherpesvirus that establishes a latency reservoir in B cells. In this work, we show that ibrutinib, idelalisib, and dasatinib, drugs that block B cell receptor (BCR) signaling and are used in the treatment of hematologic malignancies, block BCR-mediated lytic induction at clinically relevant doses. We confirm that the immunosuppressive drugs cyclosporine and tacrolimus also inhibit BCR-mediated lytic induction but find that rapamycin does not inhibit BCR-mediated lytic induction. Further investigation shows that mammalian target of rapamycin complex 2 (mTORC2) contributes to BCR-mediated lytic induction and that FK506-binding protein 12 (FKBP12) binding alone is not adequate to block activation. Finally, we show that BCR signaling can activate EBV lytic induction in freshly isolated B cells from peripheral blood mononuclear cells (PBMCs) and that activation can be inhibited by ibrutinib or idelalisib.IMPORTANCE EBV establishes viral latency in B cells. Activation of the B cell receptor pathway activates lytic viral expression in cell lines. Here we show that drugs that inhibit important kinases in the BCR signaling pathway inhibit activation of lytic viral expression but do not inhibit several other lytic activation pathways. Immunosuppressant drugs such as cyclosporine and tacrolimus but not rapamycin also inhibit BCR-mediated EBV activation. Finally, we show that BCR activation of lytic infection occurs not only in tumor cell lines but also in freshly isolated B cells from patients and that this activation can be blocked by BCR inhibitors.
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109
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Péli-Gulli MP, Raucci S, Hu Z, Dengjel J, De Virgilio C. Feedback Inhibition of the Rag GTPase GAP Complex Lst4-Lst7 Safeguards TORC1 from Hyperactivation by Amino Acid Signals. Cell Rep 2017; 20:281-288. [DOI: 10.1016/j.celrep.2017.06.058] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/02/2017] [Accepted: 06/21/2017] [Indexed: 10/25/2022] Open
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110
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Lu Y, Knapp M, Crawford K, Warne R, Elling R, Yan K, Doyle M, Pardee G, Zhang L, Ma S, Mamo M, Ornelas E, Pan Y, Bussiere D, Jansen J, Zaror I, Lai A, Barsanti P, Sim J. Rationally Designed PI3Kα Mutants to Mimic ATR and Their Use to Understand Binding Specificity of ATR Inhibitors. J Mol Biol 2017; 429:1684-1704. [PMID: 28433539 DOI: 10.1016/j.jmb.2017.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/08/2017] [Accepted: 04/11/2017] [Indexed: 12/16/2022]
Abstract
ATR, a protein kinase in the PIKK family, plays a critical role in the cell DNA-damage response and is an attractive anticancer drug target. Several potent and selective inhibitors of ATR have been reported showing significant antitumor efficacy, with most advanced ones entering clinical trials. However, due to the absence of an experimental ATR structure, the determinants contributing to ATR inhibitors' potency and specificity are not well understood. Here we present the mutations in the ATP-binding site of PI3Kα to progressively transform the pocket to mimic that of ATR. The generated PI3Kα mutants exhibit significantly improved affinity for selective ATR inhibitors in multiple chemical classes. Furthermore, we obtained the X-ray structures of the PI3Kα mutants in complex with the ATR inhibitors. The crystal structures together with the analysis on the inhibitor affinity profile elucidate the roles of individual amino acid residues in the binding of ATR inhibitors, offering key insights for the binding mechanism and revealing the structure features important for the specificity of ATR inhibitors. The ability to obtain structural and binding data for these PI3Kα mutants, together with their ATR-like inhibitor binding profiles, makes these chimeric PI3Kα proteins valuable model systems for structure-based inhibitor design.
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Affiliation(s)
- Yipin Lu
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA.
| | - Mark Knapp
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA.
| | - Kenneth Crawford
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Robert Warne
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Robert Elling
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Kelly Yan
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Michael Doyle
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Gwynn Pardee
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Li Zhang
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Sylvia Ma
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Mulugeta Mamo
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Elizabeth Ornelas
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Yue Pan
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Dirksen Bussiere
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Johanna Jansen
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Isabel Zaror
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Albert Lai
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Paul Barsanti
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Janet Sim
- Oncology, Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
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111
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Hau AM, Nakasaki M, Nakashima K, Krish G, Hansel DE. Differential mTOR pathway profiles in bladder cancer cell line subtypes to predict sensitivity to mTOR inhibition. Urol Oncol 2017; 35:593-599. [PMID: 28427860 DOI: 10.1016/j.urolonc.2017.03.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/21/2017] [Accepted: 03/22/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND Molecular classification of bladder cancer has been increasingly proposed as a potential tool to predict clinical outcomes and responses to chemotherapy. Here we focused on mechanistic target of rapamycin (mTOR) inhibition as a chemotherapeutic strategy and characterized the expression profile of mTOR signaling targets in representative bladder cancer cell lines from basal, luminal, and either basal/luminal ("non-type") molecular subtypes. MATERIALS AND METHODS Protein and mRNA expression of mTOR signaling components from representative luminal (RT4 and RT112), basal (SCaBER and 5637), and nontype (T24 and J82) bladder cancer cell line subtypes were determined by Western blot and database mining analysis of the Cancer Cell Line Encyclopedia. Cell viability following treatment with either, Torin-2 or KU-0063794, 2 dual mTOR complex 1/2 inhibitors, was determined by MTT assay. Immunoblot analysis of cells treated with Torin-2 or KU-0063794 was performed to determine the effects of mTOR inhibition on expression and phosphorylation status of mTOR signaling components, Akt, 4E-BP1, and ribosomal protein S6. RESULTS Molecular subtypes of bladder cancer cell lines each exhibited a distinct pattern of expression of mTOR-associated genes and baseline phosphorylation level of Akt and 4E-BP1. Cells with low levels of Akt Ser-473 phosphorylation were more resistant to the cytotoxic effects of mTOR inhibition with Torin-2, but not KU-0063794. Exposure to Torin-2 and KU-0063794 both potently and rapidly inhibited phosphorylation of Akt Ser-473 and Thr-308, and 4E-BP1 T37/46 in cell lines that included basal and nontype subtypes. CONCLUSIONS Differential gene expression and protein activity associated with mTOR signaling is observed among bladder cancer cell lines stratified into basal, luminal, and nontype subtypes. Urothelial carcinomas characterized by high baseline Akt Ser-473 phosphorylation may be best suited for targeted mTOR therapies.
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Affiliation(s)
- Andrew M Hau
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Manando Nakasaki
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Kazufumi Nakashima
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Goutam Krish
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - Donna E Hansel
- Department of Pathology, University of California, San Diego, La Jolla, CA; Department of Urology, University of California, San Diego, La Jolla, CA.
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112
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Liang Y, de Wispelaere M, Carocci M, Liu Q, Wang J, Yang PL, Gray NS. Structure-Activity Relationship Study of QL47: A Broad-Spectrum Antiviral Agent. ACS Med Chem Lett 2017; 8:344-349. [PMID: 28337328 PMCID: PMC5346993 DOI: 10.1021/acsmedchemlett.7b00008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/03/2017] [Indexed: 11/30/2022] Open
Abstract
Here we report the structure-activity relationship (SAR) investigations of QL-XII-47 (QL47), a compound that possesses broad-spectrum antiviral activity against dengue virus and other RNA viruses. A medicinal chemistry campaign initiated from QL47, a previously reported covalent BTK inhibitor, to derive YKL-04-085, which is devoid of any kinase activity when screened against a panel of 468 kinases and with improved pharmacokinetic properties. Both QL47 and YKL-04-085 are potent inhibitors of viral translation and exhibit cellular antiviral activity at 35-fold lower concentrations relative to inhibition of host-cell proliferation.
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Affiliation(s)
- Yanke Liang
- Department
of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, United States
- Departments of Biological Chemistry & Molecular
Pharmacology and Microbiology and
Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Melissanne de Wispelaere
- Departments of Biological Chemistry & Molecular
Pharmacology and Microbiology and
Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Margot Carocci
- Departments of Biological Chemistry & Molecular
Pharmacology and Microbiology and
Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Qingsong Liu
- Department
of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, United States
- Departments of Biological Chemistry & Molecular
Pharmacology and Microbiology and
Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Jinhua Wang
- Department
of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, United States
- Departments of Biological Chemistry & Molecular
Pharmacology and Microbiology and
Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Priscilla L. Yang
- Departments of Biological Chemistry & Molecular
Pharmacology and Microbiology and
Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Nathanael S. Gray
- Department
of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, United States
- Departments of Biological Chemistry & Molecular
Pharmacology and Microbiology and
Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
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113
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Mancini F, Teveroni E, Di Conza G, Monteleone V, Arisi I, Pellegrino M, Buttarelli M, Pieroni L, D'Onofrio M, Urbani A, Pontecorvi A, Mazzone M, Moretti F. MDM4 actively restrains cytoplasmic mTORC1 by sensing nutrient availability. Mol Cancer 2017; 16:55. [PMID: 28270148 PMCID: PMC5341177 DOI: 10.1186/s12943-017-0626-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 02/27/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Many tumor-related factors have shown the ability to affect metabolic pathways by paving the way for cancer-specific metabolic features. Here, we investigate the regulation of mTORC1 by MDM4, a p53-inhibitor with oncogenic or anti-survival activities depending on cell growth conditions. METHOD MDM4-mTOR relationship was analysed through experiments of overexpression or silencing of endogenous proteins in cell culture and using purified proteins in vitro. Data were further confirmed in vivo using a transgenic mouse model overexpressing MDM4. Additionally, the Cancer Genome Atlas (TCGA) database (N = 356) was adopted to analyze the correlation between MDM4 and mTOR levels and 3D cultures were used to analyse the p53-independent activity of MDM4. RESULTS Following nutrient deprivation, MDM4 impairs mTORC1 activity by binding and inhibiting the kinase mTOR, and contributing to maintain the cytosolic inactive pool of mTORC1. This function is independent of p53. Inhibition of mTORC1 by MDM4 results in reduced phosphorylation of the mTOR downstream target p70S6K1 both in vitro and in vivo in a MDM4-transgenic mouse. Consistently, MDM4 reduces cell size and proliferation, two features controlled by p70S6K1, and, importantly, inhibits mTORC1-mediated mammosphere formation. Noteworthy, MDM4 transcript levels are significantly reduced in breast tumors characterized by high mTOR levels. CONCLUSION Overall, these data identify MDM4 as a nutrient-sensor able to inhibit mTORC1 and highlight its metabolism-related tumor-suppressing function.
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Affiliation(s)
- Francesca Mancini
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00143, Rome, Italy. .,PostGraduate School of Endocrinology and Metabolic Diseases, Institute of Pathology, Catholic University of Rome, 00168, Rome, Italy.
| | - Emanuela Teveroni
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00143, Rome, Italy
| | - Giusy Di Conza
- Laboratory of Molecular Oncology and Angiogenesis, Department of Oncology, KU Leuven, 3000, Leuven, Belgium.,Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, 3000, Leuven, Belgium
| | - Valentina Monteleone
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00143, Rome, Italy
| | - Ivan Arisi
- European Brain Research Institute (EBRI) Rita Levi-Montalcini, 00143, Rome, Italy
| | - Marsha Pellegrino
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00143, Rome, Italy
| | - Marianna Buttarelli
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00143, Rome, Italy
| | - Luisa Pieroni
- Proteomic and Metabonomic Laboratory, Fondazione Santa Lucia, 00143, Rome, Italy
| | - Mara D'Onofrio
- European Brain Research Institute (EBRI) Rita Levi-Montalcini, 00143, Rome, Italy
| | - Andrea Urbani
- Proteomic and Metabonomic Laboratory, Fondazione Santa Lucia, 00143, Rome, Italy.,Institute of Biochemistry and Biochemical Clinic, Catholic University of Rome, 00168, Rome, Italy
| | - Alfredo Pontecorvi
- PostGraduate School of Endocrinology and Metabolic Diseases, Institute of Pathology, Catholic University of Rome, 00168, Rome, Italy
| | - Massimiliano Mazzone
- Laboratory of Molecular Oncology and Angiogenesis, Department of Oncology, KU Leuven, 3000, Leuven, Belgium.,Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, 3000, Leuven, Belgium
| | - Fabiola Moretti
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00143, Rome, Italy.
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Bi C, Zhang X, Lu T, Zhang X, Wang X, Meng B, Zhang H, Wang P, Vose JM, Chan WC, McKeithan TW, Fu K. Inhibition of 4EBP phosphorylation mediates the cytotoxic effect of mechanistic target of rapamycin kinase inhibitors in aggressive B-cell lymphomas. Haematologica 2017; 102:755-764. [PMID: 28104700 PMCID: PMC5395116 DOI: 10.3324/haematol.2016.159160] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/18/2017] [Indexed: 12/29/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) complex 1 is a central integrator of nutrient and growth factor inputs that controls cell growth in eukaryotes. The second generation of mTOR kinase inhibitors (TORKi), directly targeting the mTOR catalytic site, are more effective than rapamycin and its analogs in cancer treatment, particularly in inducing apoptosis. However, the mechanism underlying the cytotoxic effect of TORKi remains elusive. Herein, we demonstrate that TORKi-induced apoptosis is predominantly dependent on the loss of mTOR complex 1-mediated 4EBP activation. Knocking out RICTOR, a key component of mTOR complex 2, or inhibiting p70S6K has little effect on TORKi-induced apoptosis. Conversely, increasing the eIF4E:4EBP ratio by either overexpressing eIF4E or knocking out 4EBP1/2 protects lymphoma cells from TORKi-induced cytotoxicity. Furthermore, downregulation of MCL1 expression plays an important role in TORKi-induced apoptosis, whereas BCL-2 overexpression confers resistance to TORKi treatment. We further show that the therapeutic effect of TORKi in aggressive B-cell lymphomas can be predicted by BH3 profiling, and improved by combining it with pro-apoptotic drugs, especially BCL-2 inhibitors, both in vitro and in vivo Taken together, the study herein provides mechanistic insight into TORKi cytotoxicity and identified a potential way to optimize its efficacy in the clinical treatment of aggressive B-cell lymphoma.
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Affiliation(s)
- Chengfeng Bi
- Departments of Pathology and Microbiology and Hematology Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Xuan Zhang
- Departments of Pathology and Microbiology and Hematology Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Ting Lu
- Departments of Pathology and Microbiology and Hematology Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Xiaoyan Zhang
- Departments of Pathology and Microbiology and Hematology Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Xianhuo Wang
- Departments of Pathology and Microbiology and Hematology Oncology, University of Nebraska Medical Center, Omaha, NE, USA.,The Sino-US Lymphoma Center, Tianjin Medical University Cancer Institute and Hospital, National Cancer Research Center, China
| | - Bin Meng
- The Sino-US Lymphoma Center, Tianjin Medical University Cancer Institute and Hospital, National Cancer Research Center, China
| | - Huilai Zhang
- The Sino-US Lymphoma Center, Tianjin Medical University Cancer Institute and Hospital, National Cancer Research Center, China
| | - Ping Wang
- The Sino-US Lymphoma Center, Tianjin Medical University Cancer Institute and Hospital, National Cancer Research Center, China
| | - Julie M Vose
- Departments of Pathology and Microbiology and Hematology Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Wing C Chan
- Department of Pathology, City of Hope Medical Center, Duarte, CA, USA
| | | | - Kai Fu
- Departments of Pathology and Microbiology and Hematology Oncology, University of Nebraska Medical Center, Omaha, NE, USA .,The Sino-US Lymphoma Center, Tianjin Medical University Cancer Institute and Hospital, National Cancer Research Center, China
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Ronco C, Martin AR, Demange L, Benhida R. ATM, ATR, CHK1, CHK2 and WEE1 inhibitors in cancer and cancer stem cells. MEDCHEMCOMM 2016; 8:295-319. [PMID: 30108746 DOI: 10.1039/c6md00439c] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/25/2016] [Indexed: 12/15/2022]
Abstract
DNA inevitably undergoes a high number of damages throughout the cell cycle. To preserve the integrity of the genome, cells have developed a complex enzymatic machinery aimed at sensing and repairing DNA lesions, pausing the cell cycle to provide more time to repair, or induce apoptosis if damages are too severe. This so-called DNA-damage response (DDR) is yet considered as a major source of resistance to DNA-damaging treatments in oncology. Recently, it has been hypothesized that cancer stem cells (CSC), a sub-population of cancer cells particularly resistant and with tumour-initiating ability, allow tumour re-growth and cancer relapse. Therefore, DDR appears as a relevant target to sensitize cancer cells and cancer stem cells to classical radio- and chemotherapies as well as to overcome resistances. Moreover, the concept of synthetic lethality could be particularly efficiently exploited in DDR. Five kinases play pivotal roles in the DDR: ATM, ATR, CHK1, CHK2 and WEE1. Herein, we review the drugs targeting these proteins and the inhibitors used in the specific case of CSC. We also suggest molecules that may be of interest for preclinical and clinical researchers studying checkpoint inhibition to sensitize cancer and cancer stem cells to DNA-damaging treatments.
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Affiliation(s)
- Cyril Ronco
- Université Côte d'Azur , CNRS , Institut de Chimie de Nice , UMR7272 - Parc Valrose , 06108 Nice Cedex 2 , France . ; ; Tel: +33 4 92076143
| | - Anthony R Martin
- Université Côte d'Azur , CNRS , Institut de Chimie de Nice , UMR7272 - Parc Valrose , 06108 Nice Cedex 2 , France . ; ; Tel: +33 4 92076143
| | - Luc Demange
- Université Côte d'Azur , CNRS , Institut de Chimie de Nice , UMR7272 - Parc Valrose , 06108 Nice Cedex 2 , France . ; ; Tel: +33 4 92076143.,Université Paris Descartes , Sorbonne Paris Cité , UFR des Sciences Pharmaceutiques , 4 avenue de l'Observatoire , Paris Fr-75006 , France.,Université Paris Descartes , Sorbonne Paris Cité , UFR Biomédicale des Saints Pères , 45 rue des Saints Pères , France
| | - Rachid Benhida
- Université Côte d'Azur , CNRS , Institut de Chimie de Nice , UMR7272 - Parc Valrose , 06108 Nice Cedex 2 , France . ; ; Tel: +33 4 92076143
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Ong PS, Wang LZ, Dai X, Tseng SH, Loo SJ, Sethi G. Judicious Toggling of mTOR Activity to Combat Insulin Resistance and Cancer: Current Evidence and Perspectives. Front Pharmacol 2016; 7:395. [PMID: 27826244 PMCID: PMC5079084 DOI: 10.3389/fphar.2016.00395] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/07/2016] [Indexed: 12/16/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR), via its two distinct multiprotein complexes, mTORC1, and mTORC2, plays a central role in the regulation of cellular growth, metabolism, and migration. A dysregulation of the mTOR pathway has in turn been implicated in several pathological conditions including insulin resistance and cancer. Overactivation of mTORC1 and disruption of mTORC2 function have been reported to induce insulin resistance. On the other hand, aberrant mTORC1 and mTORC2 signaling via either genetic alterations or increased expression of proteins regulating mTOR and its downstream targets have contributed to cancer development. These underlined the attractiveness of mTOR as a therapeutic target to overcome both insulin resistance and cancer. This review summarizes the evidence supporting the notion of intermittent, low dose rapamycin for treating insulin resistance. It further highlights recent data on the continuous use of high dose rapamycin analogs and related second generation mTOR inhibitors for cancer eradication, for overcoming chemoresistance and for tumor stem cell suppression. Within these contexts, the potential challenges associated with the use of mTOR inhibitors are also discussed.
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Affiliation(s)
- Pei Shi Ong
- Department of Pharmacy, Faculty of Science, National University of Singapore Singapore, Singapore
| | - Louis Z Wang
- Department of Pharmacy, Faculty of Science, National University of SingaporeSingapore, Singapore; Department of Pharmacology, Yong Loo Lin School of Medicine, National University of SingaporeSingapore, Singapore
| | - Xiaoyun Dai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore Singapore, Singapore
| | - Sheng Hsuan Tseng
- Department of Pharmacy, Faculty of Science, National University of Singapore Singapore, Singapore
| | - Shang Jun Loo
- Department of Pharmacy, Faculty of Science, National University of Singapore Singapore, Singapore
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore Singapore, Singapore
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Abstract
The mammalian target of rapamycin, mTOR, plays key roles in cell growth and proliferation, acting at the catalytic subunit of two protein kinase complexes: mTOR complexes 1 and 2 (mTORC1/2). mTORC1 signaling is switched on by several oncogenic signaling pathways and is accordingly hyperactive in the majority of cancers. Inhibiting mTORC1 signaling has therefore attracted great attention as an anti-cancer therapy. However, progress in using inhibitors of mTOR signaling as therapeutic agents in oncology has been limited by a number of factors, including the fact that the classic mTOR inhibitor, rapamycin, inhibits only some of the effects of mTOR; the existence of several feedback loops; and the crucial importance of mTOR in normal physiology.
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Affiliation(s)
- Jianling Xie
- Nutrition and Metabolism, South Australian Health and Medical research Institute, Adelaide, SA, Australia
| | - Xuemin Wang
- Nutrition and Metabolism, South Australian Health and Medical research Institute, Adelaide, SA, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Christopher G Proud
- Nutrition and Metabolism, South Australian Health and Medical research Institute, Adelaide, SA, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
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118
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Soliman GA, Steenson SM, Etekpo AH. Effects of Metformin and a Mammalian Target of Rapamycin (mTOR) ATP-Competitive Inhibitor on Targeted Metabolomics in Pancreatic Cancer Cell Line. ACTA ACUST UNITED AC 2016; 6. [PMID: 28217402 DOI: 10.4172/2153-0769.1000183] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pancreatic Cancer (PC) is a devastating lethal disease. Therefore, there is an urgent need to develop new intervention strategies. The mammalian Target of Rapamycin (mTOR) is a conserved kinase and master regulator of metabolism and cell growth. mTOR is dysregulated in chronic diseases including diabetes and pancreatic cancer. Recent reports indicate that 50% of Pancreatic Ductal Adenocarcinoma (PDAC) patients are diabetic at the time of diagnosis. Furthermore, the anti-diabetic drug, metformin, which indirectly inhibits mTOR, has emerged as a potential therapeutic target for PC. The objective of this study is to determine the targeted-metabolomics profile in PDAC cell line (HPAF-II) with mTOR inhibition and the interaction between mTOR ATP-competitive inhibitor (Torin 2) and metformin as potential combined therapy in PC. HPAF-II cell lines were cultured in the presence of either Torin 2, metformin, both, or control vehicle. We utilized targeted LC/MS/MS to characterize the alterations in glycolytic and tricarboxylic acid cycle metabolomics, and employed Western Blot analysis for cell signaling activation by phosphorylation. Comparisons between groups were analyzed using one-way Analysis of Variance followed by secondary post-hoc analysis. After 1 h incubation with metformin, AMP concentration was significantly increased compared to other groups (p<0.03). After 24 h, Torin-2 significantly decreased glycolysis intermediates (fructose 1,6-bisphosphate (FBP), and 2-phosphoglycerate/3-phosphoglycerate), TCA intermediate metabolites (citrate/isocitrate, and malate), as well as Nicotinamide Adenine Dinucleotide (NAD+) and Flavin Adenine Dinucleotide (FAD), and ATP levels. When HPAF-II cells were incubated with both Torin-2 and metformin, there was a significant reduction in NAD+ and FAD, suggesting decreased levels of the energy equivalents that are available to the electron transport chain. Targeted metabolomics data indicate that mTOR complexes inhibition by Torin 2 reduced glycolytic intermediates and TCA metabolites in HPAF- II and may synergize with metformin to decrease the electron acceptors NAD+ and FAD which may lead to reduced energy production.
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Affiliation(s)
- Ghada A Soliman
- Department of Health Promotion, Social and Behavioral Health College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, 68198 USA
| | - Sharalyn M Steenson
- Department of Health Promotion, Social and Behavioral Health College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, 68198 USA
| | - Asserewou H Etekpo
- Department of Health Promotion, Social and Behavioral Health College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, 68198 USA
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119
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Roles of mTOR complexes in the kidney: implications for renal disease and transplantation. Nat Rev Nephrol 2016; 12:587-609. [PMID: 27477490 DOI: 10.1038/nrneph.2016.108] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The mTOR pathway has a central role in the regulation of cell metabolism, growth and proliferation. Studies involving selective gene targeting of mTOR complexes (mTORC1 and mTORC2) in renal cell populations and/or pharmacologic mTOR inhibition have revealed important roles of mTOR in podocyte homeostasis and tubular transport. Important advances have also been made in understanding the role of mTOR in renal injury, polycystic kidney disease and glomerular diseases, including diabetic nephropathy. Novel insights into the roles of mTORC1 and mTORC2 in the regulation of immune cell homeostasis and function are helping to improve understanding of the complex effects of mTOR targeting on immune responses, including those that impact both de novo renal disease and renal allograft outcomes. Extensive experience in clinical renal transplantation has resulted in successful conversion of patients from calcineurin inhibitors to mTOR inhibitors at various times post-transplantation, with excellent long-term graft function. Widespread use of this practice has, however, been limited owing to mTOR-inhibitor- related toxicities. Unique attributes of mTOR inhibitors include reduced rates of squamous cell carcinoma and cytomegalovirus infection compared to other regimens. As understanding of the mechanisms by which mTORC1 and mTORC2 drive the pathogenesis of renal disease progresses, clinical studies of mTOR pathway targeting will enable testing of evolving hypotheses.
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120
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Abstract
Cardiovascular disease is a leading cause of death and disability worldwide. Current treatment strategies aimed at treating the symptoms and consequences of obstructive vascular disease have embraced both optimal medical therapy and catheter-based percutaneous coronary intervention with drug-eluting stents. Drug-eluting stents elute antiproliferative drugs inhibiting vascular smooth muscle cell proliferation, which occurs in response to injury and thus prevents restenosis. However, all drugs currently approved for use in drug-eluting stents do not discriminate between proliferating vascular smooth muscle cells and endothelial cells, thus delaying re-endothelialization and subsequent vascular healing.
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Affiliation(s)
- Anwer Habib
- Division of Cardiology, Department of Internal Medicine, Emory University School of Medicine, 101 Woodruff Circle, Atlanta, GA 30322, USA
| | - Aloke Virmani Finn
- CVPath Institute Inc, 19 Firstfield Road, Gaithersburg, MD 20878, USA; Division of Cardiology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
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121
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Sadowski SM, Boufraqech M, Zhang L, Mehta A, Kapur P, Zhang Y, Li Z, Shen M, Kebebew E. Torin2 targets dysregulated pathways in anaplastic thyroid cancer and inhibits tumor growth and metastasis. Oncotarget 2016; 6:18038-49. [PMID: 25945839 PMCID: PMC4627234 DOI: 10.18632/oncotarget.3833] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/26/2015] [Indexed: 12/18/2022] Open
Abstract
Anaplastic thyroid cancer (ATC) is rare but it is one of the most lethal human malignancies with no effective therapy. There is a pressing need to identify new therapeutic agents for ATC. We performed quantitative high-throughput screening (qHTS) in ATC cell lines using a compound library of 3,282 drugs. qHTS identified 100 pan-active agents. Enrichment analysis of qHTS data showed drugs targeting mTOR were one of the most active drug categories, and Torin2 showed the highest efficacy. We found mTOR to be upregulated in ATC. Treatment of multiple ATC cell lines with Torin2 showed significant dose-dependent inhibition of cellular proliferation with caspase-dependent apoptosis and G1/S phase arrest. Torin2 inhibited cellular migration and inhibited the phosphorylation of key effectors of the mTOR-pathway (AKT, 4E-BP1 and 70S6K), as well as claspin and survivin expression, regulators of cell cycle and apoptosis. In our in vivo mouse model of metastatic ATC, Torin2 inhibited tumor growth and metastasis and significantly prolonged overall survival. Our findings suggest that Torin2 is a promising agent for ATC therapy and that it effectively targets upregulated pathways in human ATC.
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Affiliation(s)
- Samira M Sadowski
- Endocrine Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Myriem Boufraqech
- Endocrine Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lisa Zhang
- Endocrine Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Amit Mehta
- Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Payal Kapur
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yaqin Zhang
- Division of Discovery Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Zhuyin Li
- Division of Discovery Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Min Shen
- Division of Discovery Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Electron Kebebew
- Endocrine Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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122
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Udayakumar D, Pandita RK, Horikoshi N, Liu Y, Liu Q, Wong KK, Hunt CR, Gray NS, Minna JD, Pandita TK, Westover KD. Torin2 Suppresses Ionizing Radiation-Induced DNA Damage Repair. Radiat Res 2016; 185:527-38. [PMID: 27135971 DOI: 10.1667/rr14373.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Several classes of inhibitors of the mammalian target of rapamycin (mTOR) have been developed based on its central role in sensing growth factor and nutrient levels to regulate cellular metabolism. However, its ATP-binding site closely resembles other phosphatidylinositol 3-kinase-related kinase (PIKK) family members, resulting in reactivity with these targets that may also be therapeutically useful. The ATP-competitive mTOR inhibitor, Torin2, shows biochemical activity against the DNA repair-associated proteins ATM, ATR and DNA-PK, which raises the possibility that Torin2 and related compounds might radiosensitize cancerous tumors. In this study Torin2 was also found to enhance ionizing radiation-induced cell killing in conditions where ATM was dispensable, confirming the requirement for multiple PIKK targets. Moreover, Torin2 did not influence the initial appearance of γ-H2AX foci after irradiation but significantly delayed the disappearance of radiation-induced γ-H2AX foci, indicating a DNA repair defect. Torin2 increased the number of radiation-induced S-phase specific chromosome aberrations and reduced the frequency of radiation-induced CtIP and Rad51 foci formation, suggesting that Torin2 works by blocking homologous recombination (HR)-mediated DNA repair resulting in an S-phase specific DNA repair defect. Accordingly, Torin2 reduced HR-mediated repair of I-Sce1-induced DNA damage and contributed to replication fork stalling. We conclude that radiosensitization of tumor cells by Torin2 is associated with disrupting ATR- and ATM-dependent DNA damage responses. Our findings support the concept of developing combination cancer therapies that incorporate ionizing radiation therapy and Torin2 or compounds with similar properties.
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Affiliation(s)
- Durga Udayakumar
- a Department of Radiation Oncology and.,c Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, Texas 77030; and
| | - Raj K Pandita
- a Department of Radiation Oncology and.,c Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, Texas 77030; and
| | - Nobuo Horikoshi
- a Department of Radiation Oncology and.,c Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, Texas 77030; and
| | - Yan Liu
- d Center for Thoracic Oncology, Dana Farber Cancer Institute and
| | - Qingsong Liu
- e Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Kwok-Kin Wong
- d Center for Thoracic Oncology, Dana Farber Cancer Institute and
| | - Clayton R Hunt
- a Department of Radiation Oncology and.,c Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, Texas 77030; and
| | - Nathanael S Gray
- e Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - John D Minna
- b Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, Texas 75390
| | - Tej K Pandita
- a Department of Radiation Oncology and.,c Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, Texas 77030; and
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Drugging ATR: progress in the development of specific inhibitors for the treatment of cancer. Future Med Chem 2016; 7:873-91. [PMID: 26061106 DOI: 10.4155/fmc.15.33] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In this article, we review the ATR inhibitor field from initial pharmacological tools to first-generation clinical candidates with the potential to bring benefit to cancer patients. ATR is a critical part of the cell DNA-damage response. Over the past decade or more, compounds with weak ATR potency and low specificity have been used as tools in early studies to elucidate ATR pharmacology. More recently highly potent, selective and in vivo active ATR inhibitors have been developed enabling detailed preclinical in vitro and in vivo target assessment to be made. The published studies reveal the potential of ATR inhibitors for use as monotherapy or in combination with DNA-damaging agents. To date, VX-970 and AZD6738, have entered clinical assessment.
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124
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Li Z, Ji X, Wang W, Liu J, Liang X, Wu H, Liu J, Eggert US, Liu Q, Zhang X. Ammonia Induces Autophagy through Dopamine Receptor D3 and MTOR. PLoS One 2016; 11:e0153526. [PMID: 27077655 PMCID: PMC4831814 DOI: 10.1371/journal.pone.0153526] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 03/30/2016] [Indexed: 12/25/2022] Open
Abstract
Hyperammonemia is frequently seen in tumor microenvironments as well as in liver diseases where it can lead to severe brain damage or death. Ammonia induces autophagy, a mechanism that tumor cells may use to protect themselves from external stresses. However, how cells sense ammonia has been unclear. Here we show that culture medium alone containing Glutamine can generate milimolar of ammonia at 37 degrees in the absence of cells. In addition, we reveal that ammonia acts through the G protein-coupled receptor DRD3 (Dopamine receptor D3) to induce autophagy. At the same time, ammonia induces DRD3 degradation, which involves PIK3C3/VPS34-dependent pathways. Ammonia inhibits MTOR (mechanistic target of Rapamycin) activity and localization in cells, which is mediated by DRD3. Therefore, ammonia has dual roles in autophagy: one to induce autophagy through DRD3 and MTOR, the other to increase autophagosomal pH to inhibit autophagic flux. Our study not only adds a new sensing and output pathway for DRD3 that bridges ammonia sensing and autophagy induction, but also provides potential mechanisms for the clinical consequences of hyperammonemia in brain damage, neurodegenerative diseases and tumors.
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Affiliation(s)
- Zhiyuan Li
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Xinmiao Ji
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Wenchao Wang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Juanjuan Liu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
- University of Science and Technology of China, Hefei, Anhui, P. R. China
| | - Xiaofei Liang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Hong Wu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
- University of Science and Technology of China, Hefei, Anhui, P. R. China
| | - Jing Liu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Ulrike S Eggert
- Department of Chemistry and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Qingsong Liu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
- University of Science and Technology of China, Hefei, Anhui, P. R. China
| | - Xin Zhang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
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1 T moderate intensity static magnetic field affects Akt/mTOR pathway and increases the antitumor efficacy of mTOR inhibitors in CNE-2Z cells. Sci Bull (Beijing) 2015. [DOI: 10.1007/s11434-015-0950-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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DNA Damage Signalling and Repair Inhibitors: The Long-Sought-After Achilles' Heel of Cancer. Biomolecules 2015; 5:3204-59. [PMID: 26610585 PMCID: PMC4693276 DOI: 10.3390/biom5043204] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/09/2015] [Indexed: 12/16/2022] Open
Abstract
For decades, radiotherapy and chemotherapy were the two only approaches exploiting DNA repair processes to fight against cancer. Nowadays, cancer therapeutics can be a major challenge when it comes to seeking personalized targeted medicine that is both effective and selective to the malignancy. Over the last decade, the discovery of new targeted therapies against DNA damage signalling and repair has offered the possibility of therapeutic improvements in oncology. In this review, we summarize the current knowledge of DNA damage signalling and repair inhibitors, their molecular and cellular effects, and future therapeutic use.
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Venkateswarlu V, Pathania AS, Aravinda Kumar K, Mahajan P, Nargotra A, Vishwakarma RA, Malik FA, Sawant SD. 4-(N-Phenyl-N′-substituted benzenesulfonyl)-6-(4-hydroxyphenyl)quinolines as inhibitors of mammalian target of rapamycin. Bioorg Med Chem 2015; 23:4237-4247. [DOI: 10.1016/j.bmc.2015.06.046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/16/2015] [Accepted: 06/17/2015] [Indexed: 01/01/2023]
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WANG CONGREN, WANG XUEJIN, SU ZIJIAN, FEI HONGJIANG, LIU XIAOYU, PAN QUNXIONG. The novel mTOR inhibitor Torin-2 induces autophagy and downregulates the expression of UHRF1 to suppress hepatocarcinoma cell growth. Oncol Rep 2015; 34:1708-16. [DOI: 10.3892/or.2015.4146] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/29/2015] [Indexed: 11/06/2022] Open
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Tricker EM, Xu C, Uddin S, Capelletti M, Ercan D, Ogino A, Pratilas CA, Rosen N, Gray NS, Wong KK, Jänne PA. Combined EGFR/MEK Inhibition Prevents the Emergence of Resistance in EGFR-Mutant Lung Cancer. Cancer Discov 2015; 5:960-971. [PMID: 26036643 DOI: 10.1158/2159-8290.cd-15-0063] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/29/2015] [Indexed: 01/28/2023]
Abstract
UNLABELLED Irreversible pyrimidine-based EGFR inhibitors, including WZ4002, selectively inhibit both EGFR-activating and EGFR inhibitor-resistant T790M mutations more potently than wild-type EGFR. Although this class of mutant-selective EGFR inhibitors is effective clinically in lung cancer patients harboring EGFR(T790M), prior preclinical studies demonstrate that acquired resistance can occur through genomic alterations that activate ERK1/2 signaling. Here, we find that ERK1/2 reactivation occurs rapidly following WZ4002 treatment. Concomitant inhibition of ERK1/2 by the MEK inhibitor trametinib prevents ERK1/2 reactivation, enhances WZ4002-induced apoptosis, and inhibits the emergence of resistance in WZ4002-sensitive models known to acquire resistance via both T790M-dependent and T790M-independent mechanisms. Resistance to WZ4002 in combination with trametinib eventually emerges due to AKT/mTOR reactivation. These data suggest that initial cotargeting of EGFR and MEK could significantly impede the development of acquired resistance in EGFR-mutant lung cancer. SIGNIFICANCE Patients with EGFR-mutant lung cancer develop acquired resistance to EGFR and mutant-selective EGFR tyrosine kinase inhibitors. Here, we show that cotargeting EGFR and MEK can prevent the emergence of a broad variety of drug resistance mechanisms in vitro and in vivo and may be a superior therapeutic regimen for these patients.
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Affiliation(s)
- Erin M Tricker
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Chunxiao Xu
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Sharmeen Uddin
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
- Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
| | - Marzia Capelletti
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Dalia Ercan
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Atsuko Ogino
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Christine A Pratilas
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
- Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
| | - Neal Rosen
- Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
- Department of Medicine, Memorial Sloane Kettering Cancer Center, New York, New York, 10065, USA
| | - Nathanael S Gray
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Kwok-Kin Wong
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, 20115, USA
| | - Pasi A Jänne
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, 20115, USA
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Hussain AR, Al-Romaizan M, Ahmed M, Thangavel S, Al-Dayel F, Beg S, Uddin S, Siraj AK, Al-Kuraya KS. Dual Targeting of mTOR Activity with Torin2 Potentiates Anticancer Effects of Cisplatin in Epithelial Ovarian Cancer. Mol Med 2015; 21:466-78. [PMID: 26023849 DOI: 10.2119/molmed.2014.00238] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 05/25/2015] [Indexed: 12/19/2022] Open
Abstract
Mammalian target of rapamycin (mTOR) and phosphatidylinositol 3-kinase (PI3K) are two key components of PI3K/Akt/mTOR signaling pathway. Dysregulation of these pathways have been found in many cancers, including epithelial ovarian cancer (EOC), however, the role of mTOR has not been fully elucidated in Middle Eastern EOC. Therefore, we investigated the activation of mTOR complexes (mTORC1 and mTORC2) in a cohort of 156 EOC from Saudi Arabia by immunohistochemistry in a tissue microarray format. mTORC1 and mTORC2 were found to be activated in 55 of 146 (37.7%) and 63 of 140 (45%) of EOC samples, respectively. mTORC1 was significantly associated with mTORC2 (p < 0.0001) activation and both mTOR complexes were significantly associated with p-AKT (p = 0.0205 and 0.0298) and p-P70S6 (p < 0.0001 and 0.0035), respectively. Interestingly, mTOR activation incurred a poor progression-free survival (PFS) (p = 0.0188) in EOC. Next, the in vitro effect of inactivation of mTOR complexes was evaluated using a second-generation mTOR inhibitor, Torin2, on a panel of EOC cell lines. Torin2 treatment decreased cell viability and induced apoptosis in a dose-dependent manner via inactivation of mTORC1 and mTORC2 and their downstream targets in EOC cell lines. Furthermore, treatment of EOC cells with a subtoxic dose of Torin2 potentiated a cisplatin-induced apoptotic response in EOC cell lines. Finally, we studied the in vivo effect of a combination of Torin2 and cisplatin and found that this combination synergistically inhibited tumor growth in nude mice. These studies highlight the importance of targeting the mTOR survival pathway and suggest that cotreatment with cisplatin and Torin2 may be beneficial for the management of EOC.
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Affiliation(s)
- Azhar R Hussain
- Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | | | - Maqbool Ahmed
- Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Saravanan Thangavel
- Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fouad Al-Dayel
- Department of Pathology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Shaham Beg
- Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Shahab Uddin
- Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Abdul K Siraj
- Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Khawla S Al-Kuraya
- Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,AlFaisal University, Riyadh, Saudi Arabia
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Harter PN, Jennewein L, Baumgarten P, Ilina E, Burger MC, Thiepold AL, Tichy J, Zörnig M, Senft C, Steinbach JP, Mittelbronn M, Ronellenfitsch MW. Immunohistochemical Assessment of Phosphorylated mTORC1-Pathway Proteins in Human Brain Tumors. PLoS One 2015; 10:e0127123. [PMID: 25993328 PMCID: PMC4437987 DOI: 10.1371/journal.pone.0127123] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/10/2015] [Indexed: 01/14/2023] Open
Abstract
Background Current pathological diagnostics include the analysis of (epi-)genetic alterations as well as oncogenic pathways. Deregulated mammalian target of rapamycin complex 1 (mTORC1) signaling has been implicated in a variety of cancers including malignant gliomas and is considered a promising target in cancer treatment. Monitoring of mTORC1 activity before and during inhibitor therapy is essential. The aim of our study is to provide a recommendation and report on pitfalls in the use of phospho-specific antibodies against mTORC1-targets phospho-RPS6 (Ser235/236; Ser240/244) and phospho-4EBP1 (Thr37/46) in formalin fixed, paraffin embedded material. Methods and Findings Primary, established cell lines and brain tumor tissue from routine diagnostics were assessed by immunocyto-, immunohistochemistry, immunofluorescent stainings and immunoblotting. For validation of results, immunoblotting experiments were performed. mTORC-pathway activation was pharmacologically inhibited by torin2 and rapamycin. Torin2 treatment led to a strong reduction of signal intensity and frequency of all tested antibodies. In contrast phospho-4EBP1 did not show considerable reduction in staining intensity after rapamycin treatment, while immunocytochemistry with both phospho-RPS6-specific antibodies showed a reduced signal compared to controls. Staining intensity of both phospho-RPS6-specific antibodies did not show considerable decrease in stability in a timeline from 0–230 minutes without tissue fixation, however we observed a strong decrease of staining intensity in phospho-4EBP1 after 30 minutes. Detection of phospho-signals was strongly dependent on tissue size and fixation gradient. mTORC1-signaling was significantly induced in glioblastomas although not restricted to cancer cells but also detectable in non-neoplastic cells. Conclusion Here we provide a recommendation for phospho-specific immunohistochemistry for patient-orientated therapy decisions and monitoring treatment response.
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Affiliation(s)
- Patrick N. Harter
- Edinger Institute, Institute of Neurology, University of Frankfurt am Main, Frankfurt am Main, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- * E-mail: (PNH); (MWR)
| | - Lukas Jennewein
- Edinger Institute, Institute of Neurology, University of Frankfurt am Main, Frankfurt am Main, Germany
| | - Peter Baumgarten
- Edinger Institute, Institute of Neurology, University of Frankfurt am Main, Frankfurt am Main, Germany
- Department of Neurosurgery, University of Frankfurt am Main, Frankfurt am Main, Germany
| | - Elena Ilina
- Edinger Institute, Institute of Neurology, University of Frankfurt am Main, Frankfurt am Main, Germany
| | - Michael C. Burger
- German Cancer Consortium (DKTK), Heidelberg, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Senckenberg Institute of Neurooncology, University of Frankfurt am Main, Frankfurt am Main, Germany
| | - Anna-Luisa Thiepold
- Senckenberg Institute of Neurooncology, University of Frankfurt am Main, Frankfurt am Main, Germany
| | - Julia Tichy
- Senckenberg Institute of Neurooncology, University of Frankfurt am Main, Frankfurt am Main, Germany
| | - Martin Zörnig
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main, Germany
| | - Christian Senft
- German Cancer Consortium (DKTK), Heidelberg, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Neurosurgery, University of Frankfurt am Main, Frankfurt am Main, Germany
| | - Joachim P. Steinbach
- German Cancer Consortium (DKTK), Heidelberg, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Senckenberg Institute of Neurooncology, University of Frankfurt am Main, Frankfurt am Main, Germany
| | - Michel Mittelbronn
- Edinger Institute, Institute of Neurology, University of Frankfurt am Main, Frankfurt am Main, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael W. Ronellenfitsch
- German Cancer Consortium (DKTK), Heidelberg, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Senckenberg Institute of Neurooncology, University of Frankfurt am Main, Frankfurt am Main, Germany
- * E-mail: (PNH); (MWR)
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Approaches for measuring signalling plasticity in the context of resistance to targeted cancer therapies. Biochem Soc Trans 2015; 42:791-7. [PMID: 25109959 DOI: 10.1042/bst20140029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ability of cells in multicellular organisms to respond to signals in their environment is critical for their survival, development and differentiation. Once differentiated and occupying their functional niche, cells need to maintain phenotypic stability while responding to diverse extracellular perturbations and environmental signals (such as nutrients, temperature, cytokines and hormones) in a co-ordinated manner. To achieve these requirements, cells have evolved numerous intracellular signalling mechanisms that confer on them the ability to resist, respond and adapt to external changes. Although fundamental to normal biological processes, as is evident from their evolutionary conservation, such mechanisms also allow cancer cells to evade targeted therapies, a problem of immediate clinical importance. In the present article, we discuss the role of signalling plasticity in the context of the mechanisms underlying both intrinsic and acquired resistance to targeted cancer therapies. We then examine the emerging analytical techniques and theoretical paradigms that are contributing to a greater understanding of signalling on a global and untargeted scale. We conclude with a discussion on how integrative approaches to the study of cell signalling have been used, and could be used in the future, to advance our understanding of resistance mechanisms to therapies that target the kinase signalling network.
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Moschetta M, Reale A, Marasco C, Vacca A, Carratù MR. Therapeutic targeting of the mTOR-signalling pathway in cancer: benefits and limitations. Br J Pharmacol 2015; 171:3801-13. [PMID: 24780124 DOI: 10.1111/bph.12749] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/29/2014] [Accepted: 04/15/2014] [Indexed: 12/21/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) plays an important role in the regulation of protein translation, cell growth and metabolism. The mTOR protein forms two distinct multi-subunit complexes: mTORC1 and mTORC2. The mTORC1 complex is activated by diverse stimuli, such as growth factors, nutrients, energy and stress signals; and essential signalling pathways, such as PI3K and MAPK, in order to control cell growth, proliferation and survival. mTORC1 also activates S6K1 and 4EBP1, which are involved in mRNA translation. The mTORC2 complex is resistant to rapamycin inhibitory activity and is generally insensitive to nutrient- and energy-dependent signals. It activates PKC-α and Akt and regulates the actin cytoskeleton. Deregulation of the mTOR-signalling pathway (PI3K amplification/mutation, PTEN loss of function, Akt overexpression, and S6K1, 4EBP1 and eIF4E overexpression) is common in cancer, and alterations in components of the mTOR pathway have a major role in tumour progression. Therefore, mTOR is an appealing therapeutic target in many tumours. Here we summarize the upstream regulators and downstream effectors of the mTORC1 and mTORC2 pathways, the role of mTOR in cancer, and the potential therapeutic values and issues related to the novel agents targeting the mTOR-signalling pathway.
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Affiliation(s)
- M Moschetta
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Section of Internal Medicine, Department of Biomedical Sciences and Human Oncology, University of Bari Medical School 'Aldo Moro', Bari, Italy
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Sun Z, Wang Z, Liu X, Wang D. New development of inhibitors targeting the PI3K/AKT/mTOR pathway in personalized treatment of non-small-cell lung cancer. Anticancer Drugs 2015; 26:1-14. [PMID: 25304988 DOI: 10.1097/cad.0000000000000172] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Lung cancer is the leading cause of cancer-related death worldwide. Non-small-cell lung cancer (NSCLC) is the most common pathological type of lung cancer, divided into squamous cell carcinoma and adenocarcinoma. Despite better techniques of surgery and improvement in adjuvant and neoadjuvant therapy, the median survival of advanced NSCLC is only 8-10 months. With increased understanding of molecular alternations in NSCLC, considerable efforts have focused on the development of personalized molecular-targeted therapies. The PI3K/AKT/mTOR pathway regulates tumor development, growth, and proliferation of NSCLC. Various novel inhibitors targeting this pathway have been identified in preclinical studies or clinical trials. Some genetic alternations may be considered sensitive or resistant biomarkers to these inhibitors. Sometimes, upregulation of RTK and the downstream PI3K pathway or upregulation of the ERK pathway by compensatory feedback reactivation in response to these inhibitors also lead to drug resistance. Therefore, combination therapy of these inhibitors and other targeted inhibitors such as EGFR-TKI or MEK inhibitors according to genetic status and categories of inhibitors is required to enhance the efficacy of these inhibitors. Here, we reviewed the genetic status of the PI3K/AKT/mTOR pathway in NSCLC and the novel inhibitors targeting this pathway in preclinical or clinical studies, exploring the possible genetic alternations related to different inhibitors and the means to enhance the antitumor effect in NSCLC.
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Affiliation(s)
- Zhenguo Sun
- Department of Thoracic Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, China
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mTOR kinase: a possible pharmacological target in the management of chronic pain. BIOMED RESEARCH INTERNATIONAL 2015; 2015:394257. [PMID: 25685786 PMCID: PMC4313067 DOI: 10.1155/2015/394257] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/12/2014] [Indexed: 12/29/2022]
Abstract
Chronic pain represents a major public health problem worldwide. Current pharmacological treatments for chronic pain syndromes, including neuropathic pain, are only partially effective, with significant pain relief achieved in 40-60% of patients. Recent studies suggest that the mammalian target of rapamycin (mTOR) kinase and downstream effectors may be implicated in the development of chronic inflammatory, neuropathic, and cancer pain. The expression and activity of mTOR have been detected in peripheral and central regions involved in pain transmission. mTOR immunoreactivity was found in primary sensory axons, in dorsal root ganglia (DRG), and in dorsal horn neurons. This kinase is a master regulator of protein synthesis, and it is critically involved in the regulation of several neuronal functions, including the synaptic plasticity that is a major mechanism leading to the development of chronic pain. Enhanced activation of this pathway is present in different experimental models of chronic pain. Consistently, pharmacological inhibition of the kinase activity turned out to have significant antinociceptive effects in several experimental models of inflammatory and neuropathic pain. We will review the main evidence from animal and human studies supporting the hypothesis that mTOR may be a novel pharmacological target for the management of chronic pain.
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Simioni C, Cani A, Martelli AM, Zauli G, Tabellini G, McCubrey J, Capitani S, Neri LM. Activity of the novel mTOR inhibitor Torin-2 in B-precursor acute lymphoblastic leukemia and its therapeutic potential to prevent Akt reactivation. Oncotarget 2014; 5:10034-47. [PMID: 25296981 PMCID: PMC4259403 DOI: 10.18632/oncotarget.2490] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 09/15/2014] [Indexed: 01/10/2023] Open
Abstract
The PI3K/Akt/mTOR signaling cascade is a key regulatory pathway controlling cell growth and survival, and its dysregulation is a reported feature of B-precursor acute lymphoblastic leukemia (B-pre ALL). Torin-2 is a novel, second-generation ATP-competitive inhibitor that is potent and selective for mTOR with a superior pharmacokinetic profile to previous inhibitors. It has been shown that Torin-2 displayed dramatic antiproliferative activity across a panel of cancer cell lines. To investigate if Torin-2 could represent a new option for the treatment of B-pre ALL, we tested its activity on a panel of B-pre ALL cell lines. In all of them Torin-2 showed a powerful cytotoxic activity, inhibiting the growth of each cell line in a dose-dependent manner, with an IC₅₀ in the nanomolar range. Torin-2 caused both apoptosis and autophagy, induced cell cycle arrest in G₀/G₁ phase and affected both mTORC1 and mTORC2 activities as assessed by their specific substrate dephosphorylation. Torin-2 alone suppressed feedback activation of PI3K/Akt, whereas the mTORC1 inhibitor RAD001 required the addition of the Akt inhibitor MK-2206 to achieve the same effect. These pharmacological strategies targeting PI3K/Akt/mTOR at different points of the signaling pathway cascade might represent a new promising therapeutic strategy for treatment of B-pre ALL patients.
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Affiliation(s)
- Carolina Simioni
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Alice Cani
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Alberto M. Martelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giorgio Zauli
- Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, Trieste, Italy
| | - Giovanna Tabellini
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - James McCubrey
- Department of Microbiology & Immunology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Silvano Capitani
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
- LTTA Center, University of Ferrara, Ferrara, Italy
| | - Luca M. Neri
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
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Giegerich AK, Kuchler L, Sha LK, Knape T, Heide H, Wittig I, Behrends C, Brüne B, von Knethen A. Autophagy-dependent PELI3 degradation inhibits proinflammatory IL1B expression. Autophagy 2014; 10:1937-52. [PMID: 25483963 DOI: 10.4161/auto.32178] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Lipopolysaccharide (LPS)-induced activation of TLR4 (toll-like receptor 4) is followed by a subsequent overwhelming inflammatory response, a hallmark of the first phase of sepsis. Therefore, counteracting excessive innate immunity by autophagy is important to contribute to the termination of inflammation. However, the exact molecular details of this interplay are only poorly understood. Here, we show that PELI3/Pellino3 (pellino E3 ubiquitin protein ligase family member 3), which is an E3 ubiquitin ligase and scaffold protein in TLR4-signaling, is impacted by autophagy in macrophages (MΦ) after LPS stimulation. We noticed an attenuated mRNA expression of proinflammatory Il1b (interleukin 1, β) in Peli3 knockdown murine MΦ in response to LPS treatment. The autophagy adaptor protein SQSTM1/p62 (sequestosome 1) emerged as a potential PELI3 binding partner in TLR4-signaling. siRNA targeting Sqstm1 and Atg7 (autophagy related 7), pharmacological inhibition of autophagy by wortmannin as well as blocking the lysosomal vacuolar-type H(+)-ATPase by bafilomycin A1 augmented PELI3 protein levels, while inhibition of the proteasome had no effect. Consistently, treatment to induce autophagy by MTOR (mechanistic target of rapamycin (serine/threonine kinase)) inhibition or starvation enhanced PELI3 degradation and reduced proinflammatory Il1b expression. PELI3 was found to be ubiquitinated upon LPS stimulation and point mutation of PELI3-lysine residue 316 (Lys316Arg) attenuated Torin2-dependent degradation of PELI3. Immunofluorescence analysis revealed that PELI3 colocalized with the typical autophagy markers MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β) and LAMP2 (lysosomal-associated membrane protein 2). Our observations suggest that autophagy causes PELI3 degradation during TLR4-signaling, thereby impairing the hyperinflammatory phase during sepsis.
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Key Words
- ACTB, actin, beta
- ATG7, autophagy-related 7
- BECN1, Beclin 1, autophagy related
- Baf A1, bafilomycin A1
- CHX, cycloheximide
- Epoxo, epoxomycin
- HBSS, Hank's balanced salt solution
- IL1B, interleukin 1, beta
- IRAKs, interleukin-1 receptor-associated kinases
- LAMP2, lysosomal-associated membrane protein 2
- LPS
- LPS, lipopolysaccharide
- MAP1LC3B, microtubule-associated protein 1 light chain 3 beta
- MAP3K14, mitogen-activated protein kinase kinase kinase 14
- MAP3K7, mitogen-activated protein kinase kinase kinase 7
- MAPK1/3, mitogen-activated protein kinase 1/3
- MAPK14, mitogen-activated protein kinase 14
- MAPK8/9, mitogen-activated protein kinase 8/9
- MTOR, mechanistic target of rapamycin (serine/threonine kinase)
- MYD88, myeloid differentiation primary response 88
- MΦ, macrophages
- NFE2L2, nuclear factor, erythroid 2-like 2
- NFKB, nuclear factor of kappa light polypeptide gene enhancer in B-cells
- NLRP3, NLR family, pyrin domain containing 3
- PELI3
- PELI3, pellino E3 ubiquitin protein ligase family member 3
- PRRs, pattern recognition receptors
- RIPK1, receptor (TNFRSF)-interacting serine-threonine kinase 1
- Rapa, rapamycin
- SQSTM1
- SQSTM1, sequestosome 1
- TABs, TGF-beta activated kinase 1/MAP3K7 binding protein 1/2/3
- TBK1, TANK-binding kinase 1
- TICAM1, toll-like receptor adaptor molecule 1
- TLRs, toll-like receptors
- TNF, tumor necrosis factor
- TRAF6, TNF receptor-associated factor 6, E3 ubiquitin protein ligase
- TUBB, tubulin, beta class I
- Torin2
- UBB, ubiquitin B
- WT, wildtype
- Wortm, wortmannin
- autophagy
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Affiliation(s)
- Annika Klara Giegerich
- a Institute of Biochemistry I-Pathobiochemistry; Goethe University Frankfurt; Faculty of Medicine ; Frankfurt , Germany
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Derbyshire ER, Zuzarte-Luís V, Magalhães AD, Kato N, Sanschagrin PC, Wang J, Zhou W, Miduturu CV, Mazitschek R, Sliz P, Mota MM, Gray NS, Clardy J. Chemical interrogation of the malaria kinome. Chembiochem 2014; 15:1920-30. [PMID: 25111632 DOI: 10.1002/cbic.201400025] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Indexed: 01/10/2023]
Abstract
Malaria, an infectious disease caused by eukaryotic parasites of the genus Plasmodium, afflicts hundreds of millions of people every year. Both the parasite and its host utilize protein kinases to regulate essential cellular processes. Bioinformatic analyses of parasite genomes predict at least 65 protein kinases, but their biological functions and therapeutic potential are largely unknown. We profiled 1358 small-molecule kinase inhibitors to evaluate the role of both the human and the malaria kinomes in Plasmodium infection of liver cells, the parasites' obligatory but transient developmental stage that precedes the symptomatic blood stage. The screen identified several small molecules that inhibit parasite load in liver cells, some with nanomolar efficacy, and each compound was subsequently assessed for activity against blood-stage malaria. Most of the screening hits inhibited both liver- and blood-stage malaria parasites, which have dissimilar gene expression profiles and infect different host cells. Evaluation of existing kinase activity profiling data for the library members suggests that several kinases are essential to malaria parasites, including cyclin-dependent kinases (CDKs), glycogen synthase kinases, and phosphoinositide-3-kinases. CDK inhibitors were found to bind to Plasmodium protein kinase 5, but it is likely that these compounds target multiple parasite kinases. The dual-stage inhibition of the identified kinase inhibitors makes them useful chemical probes and promising starting points for antimalarial development.
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Affiliation(s)
- Emily R Derbyshire
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 (USA).
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140
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Fumarola C, Bonelli MA, Petronini PG, Alfieri RR. Targeting PI3K/AKT/mTOR pathway in non small cell lung cancer. Biochem Pharmacol 2014; 90:197-207. [DOI: 10.1016/j.bcp.2014.05.011] [Citation(s) in RCA: 271] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 05/16/2014] [Accepted: 05/16/2014] [Indexed: 01/08/2023]
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141
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Houédé N, Pourquier P. Targeting the genetic alterations of the PI3K-AKT-mTOR pathway: its potential use in the treatment of bladder cancers. Pharmacol Ther 2014; 145:1-18. [PMID: 24929024 DOI: 10.1016/j.pharmthera.2014.06.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 02/07/2023]
Abstract
Urothelial carcinoma of the bladder is the most frequent tumor of the urinary tract and represents the fifth cause of death by cancer worldwide. The current first line chemotherapy is a combination of cisplatin and gemcitabine with median survival not exceeding 15months. Vinflunine is the only drug approved by EMEA as second-line treatment and few progresses have been made for the past 20years to increase the survival of metastatic patients, especially those who are not eligible for cisplatin-based regimen. The recent studies characterizing the genetic background of urothelial cancers of the bladder, revealed chromosomal alterations that are not seen at the same level in other types of cancers. This is especially the case for mutations of genes involved in the PI3K/AKT/mTOR signaling pathway that occupies a major place in the etiology of these tumors. Here, we describe the mutations leading to constitutive activation of the PI3K/AKT/mTOR pathway and discuss the potential use of the different classes of PI3K/AKT/mTOR inhibitors in the treatment of urothelial bladder cancers. Despite the recent pivotal study evidencing specific mutations of TSC1 in bladder cancer patients responding to everolimus and the encouraging results obtained with other derivatives than rapalogs, few clinical trials are ongoing in bladder cancers. Because of the genetic complexity of these tumors, the cross-talks of the PI3K/AKT/mTOR pathway with other pathways, and the small number of eligible patients, it will be of utmost importance to carefully choose the drugs or drug combinations to be further tested in the clinic.
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Affiliation(s)
- Nadine Houédé
- Service d'Oncologie Médicale, Centre Hospitalier Universitaire de Nîmes, France; INSERM U896, Institut de Recherche en Cancérologie de Montpellier & Université de Montpellier 1, France.
| | - Philippe Pourquier
- Service d'Oncologie Médicale, Centre Hospitalier Universitaire de Nîmes, France; INSERM U896, Institut de Recherche en Cancérologie de Montpellier & Université de Montpellier 1, France
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142
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Abstract
ATR protein kinase is one of the key players in maintaining genome integrity and coordinating of the DNA damage response and repair signalling pathways. Inhibition of ATR prevents signalling from stalled replication forks and enhances the formation of DNA damage, particularly under conditions of replication stress present in cancers. For this reason ATR/CHK1 checkpoint inhibitors can potentiate the effect of DNA cross-linking agents, as evidenced by ATR inhibitors recently entering human clinical trials. This review aims to compile the existing literature on small molecule inhibitors of ATR, both from academia and the pharmaceutical industry, and will provide the reader with a comprehensive summary of this promising oncology target.
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143
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Weisberg E, Nonami A, Chen Z, Liu F, Zhang J, Sattler M, Nelson E, Cowens K, Christie AL, Mitsiades C, Wong KK, Liu Q, Gray N, Griffin JD. Identification of Wee1 as a novel therapeutic target for mutant RAS-driven acute leukemia and other malignancies. Leukemia 2014; 29:27-37. [PMID: 24791855 DOI: 10.1038/leu.2014.149] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 04/21/2014] [Accepted: 04/28/2014] [Indexed: 01/08/2023]
Abstract
Direct targeting of rat sarcoma (RAS), which is frequently mutated, has proven to be challenging, and inhibition of individual downstream RAS mediators has resulted in limited clinical efficacy. We designed a chemical screen to identify compounds capable of potentiating mammalian target of rapamycin (mTOR) inhibition in mutant RAS-positive leukemia, and identified a Wee1 inhibitor. Synergy was observed in both mutant neuroblastoma RAS viral oncogene homolog (NRAS)- and mutant kirsten RAS viral oncogene homolog (KRAS)-positive acute myelogenous leukemia (AML) cell lines and primary patient samples. The observed synergy enhanced dephosphorylation of AKT, 4E-binding protein 1 and s6 kinase, and correlated with increased apoptosis. The specificity of Wee1 as the target of MK-1775 was validated by Wee1 knockdown, as well as partial reversal of drug combination-induced apoptosis by a cyclin-dependent kinase 1 (CDK1) inhibitor. Importantly, we also extended our findings to other mutant RAS-expressing malignancies, including mutant NRAS-positive melanoma, and mutant KRAS-positive colorectal cancer, pancreatic cancer and lung cancer. We observed favorable responses with combined Wee1/mTOR inhibition in human cancer cell lines from multiple malignancies, and inhibition of tumor growth in in vivo models of mutant KRAS lung cancer and leukemia. The present study introduces for the first time Wee1 inhibition combined with mTOR inhibition as a novel therapeutic strategy for the selective treatment of mutant RAS-positive leukemia and other mutant RAS-expressing malignancies.
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Affiliation(s)
- Ellen Weisberg
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Atsushi Nonami
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Zhao Chen
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Feiyang Liu
- High Magnetic Field laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Jianming Zhang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston Massachusetts, USA
| | - Martin Sattler
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Erik Nelson
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Kristen Cowens
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Amanda L Christie
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Constantine Mitsiades
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Kwok-Kin Wong
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Qingsong Liu
- High Magnetic Field laboratory, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Nathanael Gray
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston Massachusetts, USA
| | - James D Griffin
- Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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144
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Regulation of autophagy by mTOR-dependent and mTOR-independent pathways: autophagy dysfunction in neurodegenerative diseases and therapeutic application of autophagy enhancers. Biochem Soc Trans 2014; 41:1103-30. [PMID: 24059496 DOI: 10.1042/bst20130134] [Citation(s) in RCA: 269] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Autophagy is an intracellular degradation pathway essential for cellular and energy homoeostasis. It functions in the clearance of misfolded proteins and damaged organelles, as well as recycling of cytosolic components during starvation to compensate for nutrient deprivation. This process is regulated by mTOR (mammalian target of rapamycin)-dependent and mTOR-independent pathways that are amenable to chemical perturbations. Several small molecules modulating autophagy have been identified that have potential therapeutic application in diverse human diseases, including neurodegeneration. Neurodegeneration-associated aggregation-prone proteins are predominantly degraded by autophagy and therefore stimulating this process with chemical inducers is beneficial in a wide range of transgenic disease models. Emerging evidence indicates that compromised autophagy contributes to the aetiology of various neurodegenerative diseases related to protein conformational disorders by causing the accumulation of mutant proteins and cellular toxicity. Combining the knowledge of autophagy dysfunction and the mechanism of drug action may thus be rational for designing targeted therapy. The present review describes the cellular signalling pathways regulating mammalian autophagy and highlights the potential therapeutic application of autophagy inducers in neurodegenerative disorders.
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145
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Atkin J, Halova L, Ferguson J, Hitchin JR, Lichawska-Cieslar A, Jordan AM, Pines J, Wellbrock C, Petersen J. Torin1-mediated TOR kinase inhibition reduces Wee1 levels and advances mitotic commitment in fission yeast and HeLa cells. J Cell Sci 2014; 127:1346-56. [PMID: 24424027 PMCID: PMC3953821 DOI: 10.1242/jcs.146373] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 12/13/2013] [Indexed: 01/07/2023] Open
Abstract
The target of rapamycin (TOR) kinase regulates cell growth and division. Rapamycin only inhibits a subset of TOR activities. Here we show that in contrast to the mild impact of rapamycin on cell division, blocking the catalytic site of TOR with the Torin1 inhibitor completely arrests growth without cell death in Schizosaccharomyces pombe. A mutation of the Tor2 glycine residue (G2040D) that lies adjacent to the key Torin-interacting tryptophan provides Torin1 resistance, confirming the specificity of Torin1 for TOR. Using this mutation, we show that Torin1 advanced mitotic onset before inducing growth arrest. In contrast to TOR inhibition with rapamycin, regulation by either Wee1 or Cdc25 was sufficient for this Torin1-induced advanced mitosis. Torin1 promoted a Polo and Cdr2 kinase-controlled drop in Wee1 levels. Experiments in human cell lines recapitulated these yeast observations: mammalian TOR (mTOR) was inhibited by Torin1, Wee1 levels declined and mitotic commitment was advanced in HeLa cells. Thus, the regulation of the mitotic inhibitor Wee1 by TOR signalling is a conserved mechanism that helps to couple cell cycle and growth controls.
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Affiliation(s)
- Jane Atkin
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
| | - Lenka Halova
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
| | - Jennifer Ferguson
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
| | - James R. Hitchin
- Cancer Research UK Drug Discovery Unit, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK
| | | | - Allan M. Jordan
- Cancer Research UK Drug Discovery Unit, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK
| | - Jonathon Pines
- The Gurdon Institute and Department of Zoology, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Claudia Wellbrock
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
| | - Janni Petersen
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
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146
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Ahmed M, Hussain AR, Bavi P, Ahmed SO, Al Sobhi SS, Al-Dayel F, Uddin S, Al-Kuraya KS. High prevalence of mTOR complex activity can be targeted using Torin2 in papillary thyroid carcinoma. Carcinogenesis 2014; 35:1564-72. [PMID: 24583924 DOI: 10.1093/carcin/bgu051] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) signaling cascade is a key regulatory pathway controlling initiation of messenger RNA in mammalian cells. Although dysregulation of mTOR signaling has been reported earlier in cancers, there is paucity of data about mTOR expression in papillary thyroid carcinoma (PTC). Therefore, in this study, we investigated the presence of mTORC2 and mTORC1 complexes in a large cohort of >500 PTC samples. Our clinical data showed the presence of active mTORC1 and mTORC2 in 81 and 39% of PTC samples, respectively. Interestingly, coexpression of mTORC1 and mTORC2 activity was seen in a 32.5% (164/504) of the PTC studied and this association was statistically significant (P = 0.0244). mTOR signaling complex was also found to be associated with activated AKT and 4E-BP1. In vitro, using Torin2, a second-generation mTOR inhibitor or gene silencing of mTOR expression prevented mTORC1 and mTORC2 activity leading to inactivation of P70S6, 4E-BP1, AKT and Bad. Inhibition of mTOR activity led to downregulation of cyclin D1, a gene regulated by messenger RNA translation via phosphorylation of 4E-BP1. Torin2 treatment also inhibited cell viability and induced caspase-dependent apoptosis via activation of mitochondrial apoptotic pathway in PTC cells. Finally, Torin2 treatment induces anticancer effect on PTC xenograft tumor growth in nude mice via inhibition of mTORC1 and mTORC2 and its associated pathways. Our results suggest that coexpression of mTORC1 and mTORC2 is seen frequently in the clinical PTC samples and dual targeting of mTORC1 and mTORC2 activity may be an attractive therapeutic target for treatment of PTC.
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MESH Headings
- Adaptor Proteins, Signal Transducing/metabolism
- Adenocarcinoma, Follicular/drug therapy
- Adenocarcinoma, Follicular/metabolism
- Adenocarcinoma, Follicular/pathology
- Animals
- Apoptosis/drug effects
- Blotting, Western
- Carcinoma, Papillary/drug therapy
- Carcinoma, Papillary/metabolism
- Carcinoma, Papillary/pathology
- Caspases/metabolism
- Cell Cycle/drug effects
- Cell Cycle Proteins
- Cell Proliferation/drug effects
- Cohort Studies
- Female
- Humans
- Immunoenzyme Techniques
- Male
- Mechanistic Target of Rapamycin Complex 1
- Mechanistic Target of Rapamycin Complex 2
- Mice
- Mice, Nude
- Middle Aged
- Mitochondria/drug effects
- Mitochondria/metabolism
- Multiprotein Complexes/metabolism
- Naphthyridines/pharmacology
- Neoplasm Staging
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphoproteins/metabolism
- Phosphorylation
- Prognosis
- Proto-Oncogene Proteins c-akt/metabolism
- RNA, Small Interfering/genetics
- TOR Serine-Threonine Kinases/antagonists & inhibitors
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Thyroid Neoplasms/drug therapy
- Thyroid Neoplasms/metabolism
- Thyroid Neoplasms/pathology
- Tissue Array Analysis
- Tumor Cells, Cultured
- Xenograft Model Antitumor Assays
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Affiliation(s)
| | | | | | | | | | - Fouad Al-Dayel
- Department of Pathology, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia and
| | | | - Khawla S Al-Kuraya
- Human Cancer Genomic Research, Department of Life Science, College of Science and College of Medicine, Al-Faisal University, Riyadh 11533, Saudi Arabia
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147
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Mayer S, Wrenzycki C, Tomek W. Inactivation of mTor arrests bovine oocytes in the metaphase-I stage, despite reversible inhibition of 4E-BP1 phosphorylation. Mol Reprod Dev 2014; 81:363-75. [DOI: 10.1002/mrd.22305] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 01/20/2014] [Indexed: 11/08/2022]
Affiliation(s)
| | - Christine Wrenzycki
- Faculty of Veterinary Medicine; Justus-Liebig-University Giessen, Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals; Giessen Germany
| | - Wolfgang Tomek
- Faculty of Veterinary Medicine; Justus-Liebig-University Giessen, Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals; Giessen Germany
- Leibniz-Institute for Farm Animal Biology; Institute for Reproductive Biology; Dummerstorf Germany
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148
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Xiong Y, Sheen J. The role of target of rapamycin signaling networks in plant growth and metabolism. PLANT PHYSIOLOGY 2014; 164:499-512. [PMID: 24385567 PMCID: PMC3912084 DOI: 10.1104/pp.113.229948] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 12/05/2013] [Indexed: 05/18/2023]
Abstract
The target of rapamycin (TOR) kinase, a master regulator that is evolutionarily conserved among yeasts (Saccharomyces cerevisiae), plants, animals, and humans, integrates nutrient and energy signaling to promote cell proliferation and growth. Recent breakthroughs made possible by integrating chemical, genetic, and genomic analyses have greatly increased our understanding of the molecular functions and dynamic regulation of the TOR kinase in photosynthetic plants. TOR signaling plays fundamental roles in embryogenesis, meristem activation, root and leaf growth, flowering, senescence, and life span determination. The molecular mechanisms underlying TOR-mediated ribosomal biogenesis, translation promotion, readjustment of metabolism, and autophagy inhibition are now being uncovered. Moreover, monitoring photosynthesis-derived Glc and bioenergetics relays has revealed that TOR orchestrates unprecedented transcriptional networks that wire central metabolism and biosynthesis for energy and biomass production. In addition, these networks integrate localized stem/progenitor cell proliferation through interorgan nutrient coordination to control developmental transitions and growth.
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149
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Chemical signatures and new drug targets for gametocytocidal drug development. Sci Rep 2014; 4:3743. [PMID: 24434750 PMCID: PMC3894558 DOI: 10.1038/srep03743] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 12/20/2013] [Indexed: 01/14/2023] Open
Abstract
Control of parasite transmission is critical for the eradication of malaria. However, most antimalarial drugs are not active against P. falciparum gametocytes, responsible for the spread of malaria. Consequently, patients can remain infectious for weeks after the clearance of asexual parasites and clinical symptoms. Here we report the identification of 27 potent gametocytocidal compounds (IC50 < 1 μM) from screening 5,215 known drugs and compounds. All these compounds were active against three strains of gametocytes with different drug sensitivities and geographical origins, 3D7, HB3 and Dd2. Cheminformatic analysis revealed chemical signatures for P. falciparum sexual and asexual stages indicative of druggability and suggesting potential targets. Torin 2, a top lead compound (IC50 = 8 nM against gametocytes in vitro), completely blocked oocyst formation in a mouse model of transmission. These results provide critical new leads and potential targets to expand the repertoire of malaria transmission-blocking reagents.
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150
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In vivo multiplexed interrogation of amplified genes identifies GAB2 as an ovarian cancer oncogene. Proc Natl Acad Sci U S A 2014; 111:1102-7. [PMID: 24385586 DOI: 10.1073/pnas.1311909111] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
High-grade serous ovarian cancers are characterized by widespread recurrent copy number alterations. Although some regions of copy number change harbor known oncogenes and tumor suppressor genes, the genes targeted by the majority of amplified or deleted regions in ovarian cancer remain undefined. Here we systematically tested amplified genes for their ability to promote tumor formation using an in vivo multiplexed transformation assay. We identified the GRB2-associated binding protein 2 (GAB2) as a recurrently amplified gene that potently transforms immortalized ovarian and fallopian tube secretory epithelial cells. Cancer cell lines overexpressing GAB2 require GAB2 for survival and show evidence of phosphatidylinositol 3-kinase (PI3K) pathway activation, which was required for GAB2-induced transformation. Cell lines overexpressing GAB2 were as sensitive to PI3K inhibition as cell lines harboring mutant PIK3CA. Together, these observations nominate GAB2 as an ovarian cancer oncogene, identify an alternative mechanism to activate PI3K signaling, and underscore the importance of PI3K signaling in this cancer.
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