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Zhang W, Yang C, Zou L, Zang Y, Hu J, Hu Y, Xu C, Liu R, Wang H, Xiong Z. Combining MTI-31 with RAD001 inhibits tumor growth and invasion of kidney cancer by activating autophagy. J Appl Genet 2024; 65:103-112. [PMID: 37932653 DOI: 10.1007/s13353-023-00796-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 11/08/2023]
Abstract
At most of the times, patients who are diagnosed with kidney cancer should be provided with systemic treatment as drug resistance is a challenging issue in the treatment of this disease. The progression of the cancer can be inhibited with the help of mTOR inhibitors namely RAD001 (everolimus) and MTI-31. In literature, it has been revealed that these mTOR inhibitors have the potential to stimulate autophagy. This degradation pathway boosts the survival rate of the cancerous cells that are subjected to anti-cancer therapy. In this study, CCK8, colony formation assays, and ethynyl deoxyuridine (EdU) analysis were conducted to detect cell proliferation. Furthermore, Transwell assays were also conducted for cell migration analysis. In addition to these, the researchers also performed the flow cytometry process to identify the cells that are undergoing apoptosis. In vivo, experiments were conducted to measure the growth of tumors and metastasis. In this study, the treatment provided through a combination of MTI-31 and RAD001 significantly inhibited the kidney cancer cells' proliferation and tumor growth. Furthermore, there was a notable reduction in the migration and invasion of kidney cancer cells upon the neighboring cells. The outcomes from the mechanistic studies infer that the combination of MTI-31 and RAD001 increases the LC3 levels, which in turn translates into the activation of autophagy. To conclude, the combination of MTI-31 and RAD001 improves the anti-cancerous impact produced by RAD001 in vivo through the promotion of autophagy.
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Affiliation(s)
- Wenye Zhang
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Institute of Urology, Fudan University, Shanghai, 200040, China
| | - Chen Yang
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Institute of Urology, Fudan University, Shanghai, 200040, China
| | - Lujia Zou
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Institute of Urology, Fudan University, Shanghai, 200040, China
| | - Yiwen Zang
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China
| | - Jimeng Hu
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Institute of Urology, Fudan University, Shanghai, 200040, China
| | - Yun Hu
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Institute of Urology, Fudan University, Shanghai, 200040, China
| | - Chenyang Xu
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Institute of Urology, Fudan University, Shanghai, 200040, China
| | - Rongzong Liu
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Institute of Urology, Fudan University, Shanghai, 200040, China
| | - Hao Wang
- Teaching Center of Experimental Medicine, Shanghai Medical College, Fudan University, 138 Yixueyuan Rd, Shanghai, 200032, China.
| | - Zuquan Xiong
- Huashan Hospital, Fudan University, 12 Middle Urumqi Road, Shanghai, 200040, China.
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China.
- Institute of Urology, Fudan University, Shanghai, 200040, China.
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Louis L, Chee BS, McAfee M, Nugent MJD. Design, development and in vitro quantification of novel electrosprayed everolimus-loaded Soluplus®/Polyvinyl alcohol nanoparticles via stability-indicating HPLC method in cancer therapy. Eur J Pharm Biopharm 2023; 191:235-246. [PMID: 37714413 DOI: 10.1016/j.ejpb.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/21/2023] [Accepted: 09/12/2023] [Indexed: 09/17/2023]
Abstract
Everolimus (RAD001) a mammalian target of rapamycin has been hampered by poor solubility, affecting its dissolution rate, a relationship that extends to low bioavailability. Nanoparticles (NP) based on Soluplus (SOL®) and Polyvinyl alcohol (PVA) was fabricated by electrospraying (ES) for the delivery of RAD001 to improve anti-tumour efficacy. Electrospraying with established experimental conditions produced PVA-SOL®-RAD001 NP with 71 nm mean diameter, smaller particle size distribution and >90 % encapsulation efficiency. Various polymer-drug concentrations exposed to various freeze-thaw (F/T) cycles were studied for NP optimisation and to enhance its mechanical properties. The optimised NP formulation demonstrated complete encapsulation as well as a sustained and pH dependent drug release profile for in vitro release test. In addition, to specifically study the degradation profile of RAD001 and to quantify RAD001 in the fabricated NP, a new HPLC method was developed and validated. The purpose and novelty of the HPLC method was also to ensure that RAD001 can be detected at low amounts where other conventional characterisation methods are unable to detect. The developed HPLC method was accurate, precise, robust and sensitive with LOD and LOQ values of 4.149 and 12.575 μg/mL. In conclusion, the novel developed HPLC system can be applied for the quantification of different chemotherapeutic agents and the novel electrosprayed hydrogel NP is a potential drug delivery system to increase solubility and bioavailability of RAD001 in cancer therapy.
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Affiliation(s)
- Lynn Louis
- PRISM Research Institute, Technological University of the Shannon, Athlone, Co. Westmeath, Ireland
| | - Bor Shin Chee
- PRISM Research Institute, Technological University of the Shannon, Athlone, Co. Westmeath, Ireland
| | - Marion McAfee
- Centre for Mathematical Modelling and Intelligent Systems for Health and Environment (MISHE), Atlantic Technological University, Sligo, Ireland
| | - Michael J D Nugent
- PRISM Research Institute, Technological University of the Shannon, Athlone, Co. Westmeath, Ireland.
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Gao F, Li R, Wei PF, Ou L, Li M, Bai Y, Luo WJ, Fan Z. Synergistic anticancer effects of everolimus ( RAD001) and Rhein on gastric cancer cells via phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. Bioengineered 2022; 13:6332-6342. [PMID: 35209807 PMCID: PMC8973710 DOI: 10.1080/21655979.2021.2005988] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/09/2021] [Accepted: 11/09/2021] [Indexed: 01/26/2023] Open
Abstract
Everolimus (RAD001) is a mTOR inhibitor and is widely used for the treatment of gastric cancer (GC). Evidence suggests that Rhein has anticancer effect on GC. But the synergistic effect and mechanism of RAD001 and Rhein combination on GC is not clear. The current study aims to clarify the combination of RAD001 and Rhein in GC treatment. We found Rhein dose-dependently repressed MGC-803 cell viability (50% inhibition concentration (IC50) value = 94.26 μM). Rhein (80 μM) significantly suppressed GC cell proliferation and invasion. RAD001 dose-dependently repressed MGC-803 cells viability (IC50 value = 45.41 nM). The combination of Rhein and RAD001 repressed MGC-803 cells viability, invasion, and proliferation compared to the administration of Rhein or RAD001 alone. Protein levels of epithelial-mesenchymal transition (EMT)-related molecules E-cadherin, N-cadherin and Vimentin expressions were significantly affected by the combination of Rhein and RAD001. The combination of Rhein and RAD001 significantly facilitated cell apoptosis and up-regulated expressions of cell apoptosis and cycle-related protein p53, cyclin-dependent kinase 4 (CDK4) and cyclin D1 compared to the administration of Rhein or RAD001 alone. Moreover, the combination of Rhein and RAD001 repressed the expressions of phosphorylation-phosphoinositide-3-kinase (p-PI3K), p-protein kinase B (p-AKT) and p-mammalian target of rapamycin (p-mTOR). Finally, the combination of RAD001 and Rhein significantly decreased tumor weight and volume, suppressed the expressions of p-PI3K, p-Akt and p-mTOR, and repressed cell proliferation marker Ki-67 expression, which exerted synergistic cancer prevention in GC in vivo. Overall, the combination of Rhein and RAD001 exert synergistic cancer prevention in GC via PI3K/Akt/mTOR pathway.
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Affiliation(s)
- Feng Gao
- Teaching and Research Office of Chinese Pharmacy, The College of Pharmacy of Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Rui Li
- Department of Emergency, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Pei-Feng Wei
- The Office of Drug Clinical Trial Institution, The Second Affiliated Hospital of Shaanxi University of traditional Chinese Medicine, Xianyang, Shaanxi, China
| | - Li Ou
- Teaching and Research Office of Chinese Pharmacy, The College of Pharmacy of Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Min Li
- Teaching and Research Office of Chinese Pharmacy, The College of Pharmacy of Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Yang Bai
- The Office of Drug Clinical Trial Institution, The Second Affiliated Hospital of Shaanxi University of traditional Chinese Medicine, Xianyang, Shaanxi, China
| | - Wen-Jia Luo
- Teaching and Research Office of Chinese Pharmacy, The College of Pharmacy of Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Zheng Fan
- Department of Gastroenterology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang712000, Shaanxi, China
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Chen X, Chen X, Sun X, Wang C, Wen Z, Cheng Y. RAD001 targeted HUVECs reverses 12-lipoxygenase-induced angiogenesis in oesophageal squamous cell carcinoma. J Cell Mol Med 2021; 25:6936-6947. [PMID: 34120414 PMCID: PMC8278093 DOI: 10.1111/jcmm.16705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 05/11/2021] [Accepted: 05/18/2021] [Indexed: 12/28/2022] Open
Abstract
12‐LOX plays an important role in the progression of various malignancies. However, the underlying mechanisms of the action of 12‐LOX and tumour treatment strategies remain not fully defined. In this study, we investigated the possible roles of 12‐LOX in ESCC and explored the new therapeutic target. Approximately 73% of ESCC tissues showed marked up‐regulation of 12‐LOX, which was associated with poor prognosis. 12‐LOX overexpression was positively correlated with the malignant progression of ESCC as demonstrated both in vitro and in vivo. Up‐regulation of 12‐LOX significantly increased the proliferation of ESCC cells and the xenograft volume. Moreover, 12‐LOX up‐regulation promoted tube formation of HUVECs and tumour angiogenesis in xenografts. Mechanism investigation indicated that 12‐LOX overexpression led to activation of the PI3K/AKT/mTOR pathway and the up‐regulation of VEGF in ESCC cells. Subsequent analysis indicated that the RAD001 could reverse the 12‐LOX‐induced promoting effect on ESCC. Specifically, the application of RAD001 inhibited the proliferation of ESCC cells and the tube‐forming ability of HUVECs. In the drug group, the xenografts exhibited significant volume reduction and angiogenesis inhibition. We demonstrated that RAD001 could inhibit HUVEC migration. These findings presented the evidence that RAD001 had distinct roles on HUVECs and could exert anti‐tumour effects by targeting not only the PI3K/AKT/mTOR pathway but the angiogenesis in ESCC.
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Affiliation(s)
- Xue Chen
- Departments of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, China
| | - Xuan Chen
- Departments of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, China
| | - Xiaozheng Sun
- Departments of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, China
| | - Cong Wang
- Departments of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, China
| | - Zhihua Wen
- Departments of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, China
| | - Yufeng Cheng
- Departments of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, China
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Ullrich NJ, Prabhu SP, Reddy AT, Fisher MJ, Packer R, Goldman S, Robison NJ, Gutmann DH, Viskochil DH, Allen JC, Korf B, Cantor A, Cutter G, Thomas C, Perentesis JP, Mizuno T, Vinks AA, Manley PE, Chi SN, Kieran MW. A phase II study of continuous oral mTOR inhibitor everolimus for recurrent, radiographic-progressive neurofibromatosis type 1-associated pediatric low-grade glioma: a Neurofibromatosis Clinical Trials Consortium study. Neuro Oncol 2021; 22:1527-1535. [PMID: 32236425 DOI: 10.1093/neuonc/noaa071] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Activation of the mammalian target of rapamycin (mTOR) pathway is observed in neurofibromatosis type 1 (NF1) associated low-grade gliomas (LGGs), but agents that inhibit this pathway, including mTOR inhibitors, have not been studied in this population. We evaluate the efficacy of the orally administered mTOR inhibitor everolimus for radiographically progressive NF1-associated pediatric LGGs. METHODS Children with radiologic-progressive, NF1-associated LGG and prior treatment with a carboplatin-containing chemotherapy were prospectively enrolled on this phase II clinical trial to receive daily everolimus. Whole blood was analyzed for everolimus and markers of phosphatidylinositol-3 kinase (PI3K)/mTOR pathway inhibition. Serial MRIs were obtained during treatment. The primary endpoint was progression-free survival at 48 weeks. RESULTS Twenty-three participants (median age, 9.4 y; range, 3.2-21.6 y) were enrolled. All participants were initially evaluable for response; 1 patient was removed from study after development of a malignant peripheral nerve sheath tumor. Fifteen of 22 participants (68%) demonstrated a response, defined as either shrinkage (1 complete response, 2 partial response) or arrest of tumor growth (12 stable disease). Of these, 10/15 remained free of progression (median follow-up, 33 mo). All remaining 22 participants were alive at completion of therapy. Treatment was well tolerated; no patient discontinued therapy due to toxicity. Pharmacokinetic parameters and pre-dose concentrations showed substantial between-subject variability. PI3K/mTOR pathway inhibition markers demonstrating blood mononuclear cell mTOR pathway inactivation was achieved in most participants. CONCLUSION Individuals with recurrent/progressive NF1-associated LGG demonstrate significant disease stability/shrinkage during treatment with oral everolimus with a well-tolerated toxicity profile. Everolimus is well suited for future consideration as upfront or combination therapy in this patient population.
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Affiliation(s)
- Nicole J Ullrich
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts.,Dana-Farber/Boston Children's Cancer and Blood Disorders, Dana-Farber Cancer Institution, Boston, Massachusetts
| | - Sanjay P Prabhu
- Departments of Radiology, Boston Children's Hospital, Boston, Massachusetts
| | - Alyssa T Reddy
- Department of Neurology, School of Medicine, University of California San Francisco, San Francisco, California
| | - Michael J Fisher
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Roger Packer
- Center for Neuroscience and Behavioral Medicine, Children's National Health System, Washington, DC
| | | | - Nathan J Robison
- Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, California
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri
| | | | - Jeffrey C Allen
- Departments of Pediatrics and Neurology, NYU Cancer Institute, NYU Langone Medical Center, New York, New York
| | - Bruce Korf
- Department of Genetics, University of Utah, Salt Lake City, Utah.,Department of Medical Genetics, University of Alabama, Birmingham, Alabama
| | - Alan Cantor
- Department of Preventative Medicine, University of Alabama, Birmingham, Alabama.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Gary Cutter
- School of Public Health, University of Alabama, Birmingham, Alabama.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Coretta Thomas
- School of Public Health, University of Alabama, Birmingham, Alabama.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - John P Perentesis
- Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Tomoyuki Mizuno
- Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Alexander A Vinks
- Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Peter E Manley
- Department of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts.,Dana-Farber/Boston Children's Cancer and Blood Disorders, Dana-Farber Cancer Institution, Boston, Massachusetts
| | - Susan N Chi
- Department of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts.,Dana-Farber/Boston Children's Cancer and Blood Disorders, Dana-Farber Cancer Institution, Boston, Massachusetts
| | - Mark W Kieran
- Department of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts.,Dana-Farber/Boston Children's Cancer and Blood Disorders, Dana-Farber Cancer Institution, Boston, Massachusetts
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Smit DJ, Cayrefourcq L, Haider MT, Hinz N, Pantel K, Alix-Panabières C, Jücker M. High Sensitivity of Circulating Tumor Cells Derived from a Colorectal Cancer Patient for Dual Inhibition with AKT and mTOR Inhibitors. Cells 2020; 9:cells9092129. [PMID: 32962206 PMCID: PMC7566012 DOI: 10.3390/cells9092129] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 12/24/2022] Open
Abstract
Circulating tumor cells (CTCs) are cells shed from the primary tumor into the bloodstream. While many studies on solid tumor cells exist, data on CTCs are scarce. The mortality of cancer is mostly associated with metastasis and recent research identified CTCs as initiators of metastasis. The PI3K/AKT/mTOR signaling pathway is an intracellular pathway that regulates essential functions including protein biosynthesis, cell growth, cell cycle control, survival and migration. Importantly, activating oncogenic mutations and amplifications in this pathway are frequently observed in a wide variety of cancer entities, underlining the significance of this signaling pathway. In this study, we analyzed the functional role of the PI3K/AKT/mTOR signaling pathway in the CTC-MCC-41 line, derived from a patient with metastatic colorectal cancer. One striking finding in our study was the strong sensitivity of this CTC line against AKT inhibition using MK2206 and mTOR inhibition using RAD001 within the nanomolar range. This suggests that therapies targeting AKT and mTOR could have been beneficial for the patient from which the CTC line was isolated. Additionally, a dual targeting approach of AKT/mTOR inside the PI3K/AKT/mTOR signaling pathway in the colorectal CTCs showed synergistic effects in vitro. Depending on the phenotypical behavior of CTC-MCC-41 in cell culture (adherent vs. suspension), we identified altered phosphorylation levels inside the PI3K/AKT/mTOR pathway. We observed a downregulation of the PI3K/AKT/mTOR signaling pathway, but not of the RAS/RAF/MAPK pathway, in CTCs growing in suspension in comparison to adherent CTCs. Our results highlight distinct functions of AKT isoforms in CTC-MCC-41 cells with respect to cell proliferation. Knockdown of AKT1 and AKT2 leads to significantly impaired proliferation of CTC-MCC-41 cells in vitro. Therefore, our data demonstrate that the PI3K/AKT/mTOR signaling pathway plays a key role in the proliferation of CTC-MCC-41.
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Affiliation(s)
- Daniel J. Smit
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany; (D.J.S.); (N.H.)
| | - Laure Cayrefourcq
- Laboratory of Rare Human Circulating Cells (LCCRH), University Medical Center of Montpellier, 34093 Montpellier, France; (L.C.); (C.A.-P.)
| | - Marie-Therese Haider
- Molecular Skeletal Biology Laboratory, Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany;
| | - Nico Hinz
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany; (D.J.S.); (N.H.)
| | - Klaus Pantel
- Department of Tumor Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany;
| | - Catherine Alix-Panabières
- Laboratory of Rare Human Circulating Cells (LCCRH), University Medical Center of Montpellier, 34093 Montpellier, France; (L.C.); (C.A.-P.)
| | - Manfred Jücker
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany; (D.J.S.); (N.H.)
- Correspondence: ; Tel.: +49-(0)-40-7410-56339
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Grzmil M, Qin Y, Schleuniger C, Frank S, Imobersteg S, Blanc A, Spillmann M, Berger P, Schibli R, Behe M. Pharmacological inhibition of mTORC1 increases CCKBR-specific tumor uptake of radiolabeled minigastrin analogue [ 177Lu]Lu-PP-F11N. Am J Cancer Res 2020; 10:10861-10873. [PMID: 33042258 PMCID: PMC7532663 DOI: 10.7150/thno.45440] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 08/14/2020] [Indexed: 12/13/2022] Open
Abstract
Rationale: A high tumor-to-healthy-tissue uptake ratio of radiolabeled ligands is an essential prerequisite for safe and effective peptide receptor radionuclide therapy (PRRT). In the present study, we searched for novel opportunities to increase tumor-specific uptake of the radiolabeled minigastrin analogue [177Lu]Lu-DOTA-(DGlu)6-Ala-Tyr-Gly-Trp-Nle-Asp-Phe-NH2 ([177Lu]Lu-PP-F11N), that targets the cholecystokinin B receptor (CCKBR) in human cancers. Methods: A kinase inhibitor library screen followed by proliferation and internalization assays were employed to identify compounds which can increase uptake of [177Lu]Lu-PP-F11N in CCKBR-transfected human epidermoid carcinoma A431 cells and natural CCKBR-expressing rat pancreatic acinar AR42J cells. Western blot (WB) analysis verified the inhibition of the signaling pathways and the CCKBR level, whereas the cell-based assay analyzed arrestin recruitment. Biodistribution and SPECT imaging of the A431/CCKBR xenograft mouse model as well as histological analysis of the dissected tumors were used for in vivo validation. Results: Our screen identified the inhibitors of mammalian target of rapamycin complex 1 (mTORC1), which increased cell uptake of [177Lu]Lu-PP-F11N. Pharmacological mTORC1 inhibition by RAD001 and metformin increased internalization of [177Lu]Lu-PP-F11N in A431/CCKBR and in AR42J cells. Analysis of protein lysates from RAD001-treated cells revealed increased levels of CCKBR (2.2-fold) and inhibition of S6 phosphorylation. PP-F11N induced recruitment of β-arrestin1/2 and ERK1/2 phosphorylation. In A431/CCKBR-tumor bearing nude mice, 3 or 5 days of RAD001 pretreatment significantly enhanced tumor-specific uptake of [177Lu]Lu-PP-F11N (ratio [RAD001/Control] of 1.56 or 1.79, respectively), whereas metformin treatment did not show a significant difference. Quantification of SPECT/CT images confirmed higher uptake of [177Lu]Lu-PP-F11N in RAD001-treated tumors with ratios [RAD001/Control] of average and maximum concentration reaching 3.11 and 3.17, respectively. HE staining and IHC of RAD001-treated tumors showed a significant increase in necrosis (1.4% control vs.10.6% of necrotic area) and the reduction of proliferative (80% control vs. 61% of Ki67 positive cells) and mitotically active cells (1.08% control vs. 0.75% of mitotic figures). No significant difference in the tumor vascularization was observed after five-day RAD001 or metformin treatment. Conclusions: Our data demonstrates, that increased CCKBR protein level by RAD001 pretreatment has the potential to improve tumor uptake of [177Lu]Lu-PP-F11N and provides proof-of-concept for the development of molecular strategies aimed at enhancing the level of the targeted receptor, to increase the efficacy of PRRT and nuclear imaging.
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Lu Z, Shi X, Gong F, Li S, Wang Y, Ren Y, Zhang M, Yu B, Li Y, Zhao W, Zhang J, Hou G. RICTOR/mTORC2 affects tumorigenesis and therapeutic efficacy of mTOR inhibitors in esophageal squamous cell carcinoma. Acta Pharm Sin B 2020; 10:1004-1019. [PMID: 32642408 PMCID: PMC7332809 DOI: 10.1016/j.apsb.2020.01.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/01/2019] [Accepted: 12/24/2019] [Indexed: 02/06/2023] Open
Abstract
Dysregulation of mTORC1/mTORC2 pathway is observed in many cancers and mTORC1 inhibitors have been used clinically in many tumor types; however, the mechanism of mTORC2 in tumorigenesis is still obscure. Here, we mainly explored the potential role of mTORC2 in esophageal squamous cell carcinoma (ESCC) and its effects on the sensitivity of cells to mTOR inhibitors. We demonstrated that RICTOR, the key factor of mTORC2, and p-AKT (Ser473) were excessively activated in ESCC and their overexpression is related to lymph node metastasis and the tumor-node-metastasis (TNM) phase of ESCC patients. Furthermore, we found that mTORC1/ mTORC2 inhibitor PP242 exhibited more efficacious anti-proliferative effect on ESCC cells than mTORC1 inhibitor RAD001 due to RAD001-triggered feedback activation of AKT signal. Another, we demonstrated that down-regulating expression of RICTOR in ECa109 and EC9706 cells inhibited proliferation and migration as well as induced cell cycle arrest and apoptosis. Noteworthy, knocking-down stably RICTOR significantly suppresses RAD001-induced feedback activation of AKT/PRAS40 signaling, and enhances inhibition efficacy of PP242 on the phosphorylation of AKT and PRAS40, thus potentiates the antitumor effect of RAD001 and PP242 both in vitro and in vivo. Our findings highlight that selective targeting mTORC2 could be a promising therapeutic strategy for future treatment of ESCC.
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Key Words
- 4EBP-1, E binding protein-1
- AKT
- AKT, protein kinase B (PKB)
- ESCC, esophageal squamous cell carcinoma
- Esophageal squamous cell carcinoma
- FDA, U.S. Food and Drug Administration
- H&E staining, hematoxylin and eosin staining
- IC50, half maximal inhibitory concentration
- PI3K, phosphatidylinositol 3 kinase
- RAD001
- RICTOR
- RICTOR, rapamycin-insensitive companion of mTOR
- TNM, tumor-node-metastasis
- TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling
- mTOR, mammalian target of rapamycin
- mTORC1, mTOR complex 1
- mTORC2, mTOR complex 2
- p70S6K, p70 ribosomal S6 kinase-1
- pp242
- rapalogs, rapamycin and its analogs
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Wichmann CW, Goh YW, Parslow AC, Rigopoulos A, Guo N, Scott AM, Ackermann U, White JM. Synthesis and validation of [ 18F]mBPET-1, a fluorine-18 labelled mTOR inhibitor derivative based on a benzofuran backbone. EJNMMI Radiopharm Chem 2020; 5:3. [PMID: 31974638 PMCID: PMC6977806 DOI: 10.1186/s41181-020-0089-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/06/2020] [Indexed: 12/18/2022] Open
Abstract
Background Targeted therapy of HER2 positive breast cancer has led to clinical success in some cases with primary and secondary resistance being major obstacles. Due to the substantial involvement of mTOR kinase in cell growth and proliferation pathways it is now targeted in combination treatments to counteract HER2 targeted therapy resistance. However, the selection of receptive patient populations for a specific drug combination is crucial. This work aims to develop a molecular probe capable of identifying patients with tumour populations which are receptive to RAD001 combination therapy. Based on the structure of a mTOR inhibitor specific for mTORC1, we designed, synthesised and characterised a novel benzofuran based molecular probe which suits late stage fluorination via Click chemistry. Results Synthesis of the alkyne precursor 5 proceeded in 27.5% yield over 7 linear steps. Click derivatisation gave the non-radioactive standard in 25% yield. Radiosynthesis of [18F]1-((1-(2-Fluoroethyl)-1H-1,2,3-triazol-4-yl) methyl)-4-((5-methoxy-2-phenylbenzofuran-4-yl) methyl) piperazine ([18F]mBPET-1) proceeded over two steps which were automated on an iPhase FlexLab synthesis module. In the first step, 2-[18F]fluoroethylazide ([18F]6) was produced, purified by automated distillation in 60% non-decay-corrected yield and subjected to Click conditions with 5. Semi-preparative RP-HPLC purification and reformulation gave [18F]mBPET-1 in 40% ± 5% (n = 6) overall RCY with a process time of 90 min. Radiochemical purity was ≥99% at end of synthesis (EOS) and ≥ 98% after 4 h at room temperature. Molar activities ranged from typically 24.8 GBq/μmol (EOS) to a maximum of 78.6 GBq/μmol (EOS). Lipophilicity of [18F]mBPET-1 was determined at pH 7.4 (logD7.4 = 0.89). [18F]mBPET-1 showed high metabolic stability when incubated with mouse S9 liver fractions which resulted in a 0.8% drop in radiochemical purity after 3 h. Cell uptake assays showed 1.3–1.9-fold increased uptake of the [18F]mBPET-1 in RAD001 sensitive compared to insensitive cells across a panel of 4 breast cancer cell lines. Conclusion Molecular targeting of mTOR with [18F]mBPET-1 distinguishes mTOR inhibitor sensitive and insensitive cell lines. Future studies will explore the ability of [18F]mBPET-1 to predict response to mTOR inhibitor treatment in in vivo models.
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Affiliation(s)
- Christian W Wichmann
- The University of Melbourne, Parkville, VIC, 3010, Australia. .,Department of Molecular Imaging and Therapy, Austin Hospital, 145 Studley Road, Heidelberg, VIC, 3084, Australia. .,Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, VIC, 3084, Australia. .,School of Cancer Medicine, La Trobe University, Plenty Road & Kingsbury Drive, Bundoora, VIC, 3086, Australia.
| | - Yit Wooi Goh
- Department of Molecular Imaging and Therapy, Austin Hospital, 145 Studley Road, Heidelberg, VIC, 3084, Australia
| | - Adam C Parslow
- Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, VIC, 3084, Australia.,School of Cancer Medicine, La Trobe University, Plenty Road & Kingsbury Drive, Bundoora, VIC, 3086, Australia
| | - Angela Rigopoulos
- Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, VIC, 3084, Australia.,School of Cancer Medicine, La Trobe University, Plenty Road & Kingsbury Drive, Bundoora, VIC, 3086, Australia
| | - Nancy Guo
- Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, VIC, 3084, Australia
| | - Andrew M Scott
- The University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Molecular Imaging and Therapy, Austin Hospital, 145 Studley Road, Heidelberg, VIC, 3084, Australia.,Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, VIC, 3084, Australia.,School of Cancer Medicine, La Trobe University, Plenty Road & Kingsbury Drive, Bundoora, VIC, 3086, Australia
| | - Uwe Ackermann
- The University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Molecular Imaging and Therapy, Austin Hospital, 145 Studley Road, Heidelberg, VIC, 3084, Australia.,Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, VIC, 3084, Australia.,School of Cancer Medicine, La Trobe University, Plenty Road & Kingsbury Drive, Bundoora, VIC, 3086, Australia
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10
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Wu K, Sun XQ, Wang CQ, Gao TX, Sun P, Wang Y, Jiang WQ, Li ZM, Huang JJ. Metronomic combination chemotherapy using everolimus and etoposide for the treatment of non-Hodgkin lymphoma. Cancer Med 2019; 8:4688-4698. [PMID: 31218841 PMCID: PMC6712471 DOI: 10.1002/cam4.2364] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 01/07/2023] Open
Abstract
Patients with Non-Hodgkin lymphoma (NHL) treated by conventional chemotherapeutic drugs usually require a long recovery period. However, metronomic combination chemotherapy (MCC) enhances therapeutic efficacy and decreases side effects in the treatment of NHL. In this study, we tested and compared the effects of metronomic chemotherapy (MC) using podophyllotoxin derivative etoposide (VP-16) alone and that of MCC using both VP-16 and everolimus (RAD001) in the treatment of NHL. Two types of NHL cells, OCI-LY-10 and SU-DHL-6, were employed for the experiments. Cell proliferation, apoptosis, and cell senescence were measured to test the effects of drugs in each experiment. In addition, the influences of MC and MCC on the cell cycle and autophagy pathway were evaluated to study the functional mechanisms behind their effects. Finally, we conducted analyses of the growth inhibitory effect and synergistic activity for different MCC. The results showed that MC using low-dose VP-16 alone demonstrated strong treatment effects in terms of inducing apoptosis, cell senescence, and reducing tumor cell proliferation, and this treatment also led to changes of the cell cycle. Compared with MC, MCC using VP-16 and RAD001 together demonstrated even stronger treatment effects, with both the cell cycle and autophagy-related proteins being affected. Considering the synergistic activity, our results showed the MCC of VP-16 48 hours + RAD001 24 hours is the optimal method for treating NHL.
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Affiliation(s)
- Ke Wu
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Xiao-Qing Sun
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Cai-Qin Wang
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Tian-Xiao Gao
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Peng Sun
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yu Wang
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Wen-Qi Jiang
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Zhi-Ming Li
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Jia-Jia Huang
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
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11
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Abstract
Everolimus (RAD001) is an oral protein kinase inhibitor of the mTOR (mammalian target of rapamycin) serine/threonine kinase signal transduction pathway. The mTOR pathway regulates cell growth, proliferation and survival, and is frequently deregulated in cancer.The EMA has approved Everolimus as Afinitor® for the treatment of hormone receptor-positive, HER2/neu-negative advanced breast cancer, in combination with exemestane, in postmenopausal women without symptomatic visceral disease after recurrence or progression following a nonsteroidal aromatase inhibitor, for the treatment of unresectable or metastatic, well- or moderately differentiated neuroendocrine tumors of pancreatic origin in adults with progressive disease, and for the treatment of unresectable or metastatic, well-differentiated (Grade 1 or Grade 2) nonfunctional neuroendocrine tumors of gastrointestinal or lung origin in adults with progressive disease, and for the treatment of patients with advanced renal cell carcinoma, whose disease has progressed on or after treatment with VEGF-targeted therapy And as Votubia® for the treatment of adult patients with renal angiomyolipoma associated with tuberous sclerosis complex (TSC), who are at risk of complications (based on factors such as tumor size or presence of aneurysm, or presence of multiple or bilateral tumors) but who do not require immediate surgery, and for the treatment of patients with subependymal giant cell astrocytoma (SEGA) associated with TSC who require therapeutic intervention but are not amenable to surgery, and as an add-on treatment in patients from 2 years of age with seizures related to TSC that have not responded to other treatments ( https://www.novartis.com/news/media-releases/novartis-drug-votubiar-receives-eu-approval-treat-refractory-partial-onset ). The FDA has approved Everolimus as Afinitor® for the treatment of postmenopausal women with advanced hormone receptor-positive, HER2-negative breast cancer in combination with exemestane, after the failure of treatment with letrozole or anastrozole, for the treatment of adult patients with progressive neuroendocrine tumors of pancreatic origin (PNET) with unresectable, locally advanced or metastatic disease, for the treatment of adult patients with advanced RCC after failure of treatment with sunitinib or sorafenib, for the treatment of adult patients with renal angiomyolipoma and tuberous sclerosis complex (TSC), not requiring immediate surgery. for the treatment of adult and pediatric patients, 3 years of age or older, with SEGA associated with TSC who require therapeutic intervention but are not candidates for curative surgical resection. Everolimus shows promising clinical activity in additional indications. Multiple Phase II and Phase III trials of everolimus alone or in combination and will help to further elucidate the role of mTOR in oncology. For a review on everolimus as immunosuppressant, please consult other sources.
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12
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Avniel-Polak S, Leibowitz G, Doviner V, Gross DJ, Grozinsky-Glasberg S. Combining chloroquine with RAD001 inhibits tumor growth in a NEN mouse model. Endocr Relat Cancer 2018; 25:677-686. [PMID: 29636368 DOI: 10.1530/erc-18-0121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 04/10/2018] [Indexed: 12/12/2022]
Abstract
Patients with neuroendocrine neoplasms (NENs) often require systemic treatment, which is frequently limited by the emergence of drug resistance. mTOR inhibitors (mTORi), such as RAD001 (everolimus), have been shown to inhibit neoplasm progression. mTORi stimulates autophagy, a degradation pathway that might promote the survival of neoplasm cells that are exposed to anti-cancer therapy. Chloroquine (CQ), a well-known anti-malarial and anti-rheumatic drug, suppresses autophagy. Based on our previous results, we hypothesized that CQ may enhance the anti-tumorigenic effects of mTORi by inhibiting autophagy and we aimed to examine the anti-tumorigenic effect of CQ, alone or in combination with RAD001. We established a NEN subcutaneous xenograft mouse model and evaluated the effect of the drugs on tumor growth, mTOR pathway, autophagy and apoptosis. CQ alone and in combination with RAD001 significantly decreased neoplasm volume. Histopathological analysis revealed that the combination of CQ and RAD001 markedly inhibited mTOR activity and neoplasm cell growth, along with accumulation of autophagosomes and increased apoptosis. In conclusion, CQ enhances the anti-tumorigenic effect of RAD001 in vivo by inhibiting autophagy. Clinical trials addressing the effects of CQ therapy on neoplasm progression in patients with NENs, mainly in those treated with mTORi, are warranted.
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Affiliation(s)
- Shani Avniel-Polak
- Neuroendocrine Tumor LaboratoryEndocrinology & Metabolism Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Gil Leibowitz
- Neuroendocrine Tumor LaboratoryEndocrinology & Metabolism Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Victoria Doviner
- Department of PathologyShaare Zedek Medical Center, Jerusalem, Israel
| | - David J Gross
- Neuroendocrine Tumor LaboratoryEndocrinology & Metabolism Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Simona Grozinsky-Glasberg
- Neuroendocrine Tumor LaboratoryEndocrinology & Metabolism Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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Lamberti G, Brighi N, Maggio I, Manuzzi L, Peterle C, Ambrosini V, Ricci C, Casadei R, Campana D. The Role of mTOR in Neuroendocrine Tumors: Future Cornerstone of a Winning Strategy? Int J Mol Sci 2018; 19:ijms19030747. [PMID: 29509701 PMCID: PMC5877608 DOI: 10.3390/ijms19030747] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/28/2018] [Accepted: 03/05/2018] [Indexed: 12/13/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) is part of the phosphoinositide-3-kinase (PI3K)/protein kinase B (AkT)/mTOR pathway and owes its name to the inhibitory effect of rapamycin. The mTOR has a central converging role for many cell functions, serving as a sensor for extracellular signals from energy status and nutrients availability, growth factors, oxygen and stress. Thus, it also modulates switch to anabolic processes (protein and lipid synthesis) and autophagy, in order to regulate cell growth and proliferation. Given its functions in the cell, its deregulation is implicated in many human diseases, including cancer. Its predominant role in tumorigenesis and progression of neuroendocrine tumors (NETs), in particular, has been demonstrated in preclinical studies and late clinical trials. mTOR inhibition by everolimus is an established therapeutic target in NETs, but there are no identified predictive or prognostic factors. This review is focused on the role of mTOR and everolimus in NETs, from preclinical studies to major clinical trials, and future perspectives involving mTOR in the treatment of NETs.
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Affiliation(s)
- Giuseppe Lamberti
- Department of Experimental, Diagnostic and Specialty Medicine, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
| | - Nicole Brighi
- Department of Experimental, Diagnostic and Specialty Medicine, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
| | - Ilaria Maggio
- Department of Experimental, Diagnostic and Specialty Medicine, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
| | - Lisa Manuzzi
- Department of Experimental, Diagnostic and Specialty Medicine, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
| | - Chiara Peterle
- Department of Experimental, Diagnostic and Specialty Medicine, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
| | - Valentina Ambrosini
- Nuclear Medicine Unit, Medicina Nucleare Metropolitana, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
| | - Claudio Ricci
- Department of Medical and Surgical Sciences, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
| | - Riccardo Casadei
- Department of Medical and Surgical Sciences, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
| | - Davide Campana
- Department of Medical and Surgical Sciences, S.Orsola-Malpighi University Hospital, 40138 Bologna, Italy.
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Ishikawa C, Senba M, Mori N. Effects of NVP-BEZ235, a dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor, on HTLV-1-infected T-cell lines. Oncol Lett 2018; 15:5311-5317. [PMID: 29552172 DOI: 10.3892/ol.2018.7979] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 01/29/2018] [Indexed: 01/25/2023] Open
Abstract
Adult T-cell leukemia (ATL) is an aggressive type of malignancy caused by human T-cell leukemia virus type 1 (HTLV-1). In ATL, the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway is constitutively active, promoting cell proliferation, survival and chemoresistance. Thus, the PI3K signaling pathway is an attractive therapeutic target for ATL. In the present study, the effects of RAD001 (an mTOR inhibitor), NVP-BKM120 (a pan-PI3K inhibitor) and NVP-BEZ235 (a novel dual PI3K/mTOR inhibitor) on cultured HTLV-1-infected T-cell lines were compared. The results demonstrated that NVP-BEZ235 was more efficacious compared with RAD001 and NVP-BKM120 at inhibiting cell growth. NVP-BEZ235 exhibited cytostatic rather than cytotoxic effects on various HTLV-1-infected T-cell lines, where it induced cell cycle arrest at G1 phase. NVP-BEZ235 downregulated cyclin D1, cyclin D2, cyclin E, cyclin dependent kinase (CDK)2 and CDK4 expression, and the phosphorylation of retinoblastoma protein. In C.B-17/Icr-severe combined immune deficiency mice implanted with HTLV-1-infected HUT-102 cells, oral NVP-BEZ235 caused marked retardation of tumor growth compared with the control. The present in vitro and in vivo studies highlight the efficacious dual inhibition of PI3K, and mTOR following NVP-BEZ235 treatment. Thus, the results of the current study provide preclinical rationale for phase I clinical studies to examine the effects of NVP-BEZ235 in patients with ATL.
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Affiliation(s)
- Chie Ishikawa
- Division of Health Sciences, Transdisciplinary Research Organization for Subtropics and Island Studies, University of The Ryukyus, Nishihara, Okinawa 903-0213, Japan.,Department of Microbiology and Oncology, Graduate School of Medicine, University of The Ryukyus, Nishihara, Okinawa 903-0215, Japan
| | - Masachika Senba
- Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
| | - Naoki Mori
- Department of Microbiology and Oncology, Graduate School of Medicine, University of The Ryukyus, Nishihara, Okinawa 903-0215, Japan
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15
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Tsai TF, Lin JF, Chou KY, Lin YC, Chen HE, Hwang TIS. miR-99a-5p acts as tumor suppressor via targeting to mTOR and enhances RAD001-induced apoptosis in human urinary bladder urothelial carcinoma cells. Onco Targets Ther 2018; 11:239-252. [PMID: 29379304 PMCID: PMC5757495 DOI: 10.2147/ott.s114276] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Introduction miR-99a-5p, known to play an important role in mammalian target of rapamycin (mTOR) regulation, is downregulated in human bladder cancer. The study aimed to investigate the anticancer activity of miR-99a-5p and the possible mechanism associated with mTOR in bladder cancer cells. Materials and methods Vectors expressing miR-99a-5p were transfected into human urinary bladder urothelial carcinoma (5637 and T24) cells. The level of miR-99a-5p was monitored by microRNA (miRNA) quantitative polymerase chain reaction (QPCR). Luciferase reporter assays were performed to verify the direct binding of miR-99a-5p to mTOR transcripts. The mTOR transcripts and protein levels were measured by QPCR and Western blot, respectively. Cell viability of miR-99a-5p-transfected cells was detected by tetrazolium salt (WST-1). Inhibition of mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) signaling was detected by the phosphorylation of mTOR and AKT using Western blot. The ability of miR-99a-5p to enhance RAD001-induced apoptosis was determined as the expression of cleaved caspase 3 and levels of DNA fragmentation. Results Transfection of miR-99a-5p-expressing vector elevated the expression level of miR-99a-5p up to sixfold compared to vector-only controls. The results from luciferase assay verified that miR-99a-5p directly binds to the predicted sequence in the 3′ untranslated region (3′-UTR) of mTOR. The levels of mTOR RNA and protein were decreased in miR-99a-5p-transfected cells. Dual inhibition of mTORC1 and mTORC2 by miR-99a-5p was confirmed by the decreased phosphorylation of mTOR (at Ser2448 and Ser2481), phospho-rpS6 and phospho-4EBP1. The phosphorylation of AKT was significantly inhibited in miR-99a-5p-transfected cells upon RAD001 treatment. Enforced expression of miR-99a-5p potentiated RAD001-induced apoptosis in these cells. Conclusion This is the first study showing that miR-99a-5p markedly inhibits the growth of bladder cancer cells via dual inhibition of mTORC1 and mTORC2. Our data demonstrated that forced expression of miR-99a-5p inhibits the feedback of AKT survival pathway and enhances the induction of apoptosis in RAD001-treated bladder cancer cells.
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Affiliation(s)
| | | | | | | | | | - Thomas I-Sheng Hwang
- Department of Urology.,Division of Urology, Department of Surgery, Shin-Kong Wu Ho-Su Memorial Hospital.,Department of Urology, Taipei Medical University.,Division of Urology, School of Medicine, Fu-Jen Catholic University, Taipei, Taiwan, Republic of China
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16
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Hong B, Wang H, Deng K, Wang W, Dai H, Yan Lui VW, Lin W. Combination treatment of RAD001 and BEZ235 exhibits synergistic antitumor activity via down-regulation of p-4E-BP1/Mcl-1 in small cell lung cancer. Oncotarget 2017; 8:106486-98. [PMID: 29290965 DOI: 10.18632/oncotarget.18984] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 06/18/2017] [Indexed: 11/25/2022] Open
Abstract
Small cell lung cancer (SCLC) is a highly malignant cancer with few targeted therapies. In the study, by mining the Cancer Cell Line Encyclopedia (CCLE) database, we found that PI3K/AKT/mTOR pathway was aberrant in 92% of SCLC cell lines. Moreover, we found that the phosphorylation level of 4E-BP1 was significantly correlated with SCLC sensitivity to RAD001 (mTOR inhibitor) and BEZ235 (PI3K/mTOR dual inhibitor). Combination of RAD001 and BEZ235 synergistically inhibited the growth of SCLC cells, which was accompanied by enhanced induction of cell cycle arrest and apoptosis. Such a combination dramatically inhibited the activation of AKT, and strongly reduced the phosphorylation of 4E-BP1 and its downstream target Mcl-1. Knock-down of Mcl-1 enhanced the growth inhibition of SCLC cells induced by RAD001 and BEZ235 co-treatment, whereas over-expression of Mcl-1 reduced the growth inhibitory effect. Furthermore, in vivo study demonstrated that the combination treatment suppressed tumor growth more effectively than RAD001 or BEZ235 treatment alone. In summary, our study suggests that combination of BEZ235 and RAD001 may be an effective regimen for SCLC treatment, and p-4E-BP1 may serve as a predictive biomarker for SCLC response to mTOR inhibitor.
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Abstract
Endometrial cancer (EC) is now one of the most common malignant tumors in young women. In all, 90% of young patients with EC have a high expression of progesterone recep tor, can be treated with progestin, and have very good prognosis. However, some of the young EC patients are resistant to progestin, the mechanism of which is unclear. To illuminate the mechanism by which endometrial cells acquire progestin resistance, we treated Ishikawa cells by slowly increasing dosage of progestin and established a progestin-resistant cell subline. We show here that progesterone resistant cells acquire increased proliferation rate and interestingly decreased autophagy. To uncover the mechanism by which cells increase proliferation and bypass autophagy, we found higher activation of phosphatidylinositol 3-kinase/AKT/mTOR signaling pathway was necessary to this malignant acquirement by RNAi technique. Further, we elucidated that activation of mTOR was sufficient and necessary for progestin resistance. RAD001, an inhibitor of mTOR, decreased phosphorylation of mTOR and inhibited proliferation of progestin-resistant cancer cells by promoting autophagy. Thus, our results indicated that mTOR can be a target to treat the progestin-resistant EC.
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Affiliation(s)
- Hua Liu
- Department of Gynecology, Affiliated Hospital of Qingdao Medical College, Qingdao University, Qingdao.,Department of Gynecology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong, People's Republic of China
| | - Liqin Zhang
- Department of Gynecology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong, People's Republic of China
| | - Xuyan Zhang
- Department of Gynecology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong, People's Republic of China
| | - Zhumei Cui
- Department of Gynecology, Affiliated Hospital of Qingdao Medical College, Qingdao University, Qingdao
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18
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Dalbagni G, Benfante N, Sjoberg DD, Bochner BH, Machele Donat S, Herr HW, Mc Coy AS, Fahrner AJ, Retinger C, Rosenberg JE, Bajorin DF. Single Arm Phase I/II Study of Everolimus and Intravesical Gemcitabine in Patients with Primary or Secondary Carcinoma In Situ of the Bladder who failed Bacillus Calmette Guerin (NCT01259063). Bladder Cancer 2017; 3:113-119. [PMID: 28516156 PMCID: PMC5409047 DOI: 10.3233/blc-170095] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background: Standard treatment for BCG-refractory urothelial cancer is radical cystectomy. Identification of active agents is clearly warranted. Objective: To determine a safe dose of oral everolimus in combination with standard intravesical gemcitabine and to evaluate the efficacy of this combination. Methods: Patients with carcinoma in situ refractory to intravesical bacillus Calmette-Guérin and refusing cystectomy were eligible. Patients in the phase I part of the trial received one of three dose levels of oral everolimus. Patients also received a fixed dose of intravesical gemcitabine. Maintenance everolimus was given for 12 months in patients achieving a complete response confirmed by cystoscopy and cytology. Patients in phase II received continuous everolimus administered at 10 mg daily with intravesical gemcitabine followed by everolimus maintenance for 12 months of total therapy. The enrollment goal for the phase II was 33 patients. Results: 14 patients were enrolled in phase I of the trial. 23 patients were enrolled in phase II of the trial and 19 were evaluable for primary and secondary endpoints. Four patients withdrew consent prior to treatment initiation. Of the 19 patients evaluable for response, 3 (16%, 95% confidence interval [CI] 3% – 40%) were disease free at 1 yr. The probability of RFS was 20% (95% CI 5% – 42%) at 12 months. Ten patients out of 19 had grade 3 or greater toxicity events. Seven withdrew consent or were taken off study. Conclusions: Many patients withdrew, and enrollment was halted. Continuous oral everolimus plus intravesical gemcitabine was not well tolerated in this patient population where the threshold for tolerability is low.
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Affiliation(s)
- Guido Dalbagni
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Nicole Benfante
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Daniel D Sjoberg
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Bernard H Bochner
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - S Machele Donat
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Harry W Herr
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Asia S Mc Coy
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Alicia J Fahrner
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Caitlyn Retinger
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jonathan E Rosenberg
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Dean F Bajorin
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Wang H, Li D, Li X, Ou X, Liu S, Zhang Y, Ding J, Xie B. Mammalian target of rapamycin inhibitor RAD001 sensitizes endometrial cancer cells to paclitaxel-induced apoptosis via the induction of autophagy. Oncol Lett 2016; 12:5029-5035. [PMID: 28105210 PMCID: PMC5228433 DOI: 10.3892/ol.2016.5338] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/08/2016] [Indexed: 12/11/2022] Open
Abstract
The aim of the present study was to investigate the effects of the mammalian target of rapamycin (mTOR) inhibitor, RAD001, on the growth of human endometrial cancer cells. The effects of RAD001 on human endometrial cancer Ishikawa and HEC-1A cell proliferation were determined by MTT assay. Green fluorescent protein microtubule-associated protein 1 light chain 3α (GFP-LC3) protein aggregates were observed under a confocal microscope, and Ishikawa and HEC-1A cell apoptosis was detected using flow cytometry. The expression levels of LC3-I, LC3-II and mTOR proteins were detected by western blot analysis. The results showed that RAD001 effectively inhibited human endometrial cancer Ishikawa and HEC-1A cell proliferation via downregulation of AKT/mTOR phosphorylation. Moreover, RAD001 induced autophagic cell death and a higher sensitivity to paclitaxel-induced apoptosis. These results indicate that RAD001 could have therapeutic potential in human endometrial cancer with hyperactivated AKT/mTOR signaling.
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Affiliation(s)
- Huan Wang
- Department of Gynecology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Dandan Li
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong 510060, P.R. China
| | - Xiaomao Li
- Department of Gynecology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Xueling Ou
- Department of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510089, P.R. China
| | - Suiling Liu
- Department of Gynecology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Yu Zhang
- Department of Gynecology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Jie Ding
- Department of Gynecology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Bo Xie
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510089, P.R. China
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20
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Lee H, Lee J, Sohn I, Park SH, Park JO, Park YS, Kim KM, Kang WK, Kim ST. To Excavate Biomarkers Predictive of the Response for Capecitabine plus RAD001 through Nanostring-Based Multigene Assay in Advanced Gastric Cancer Patients. J Cancer 2016; 7:2173-2178. [PMID: 27994652 PMCID: PMC5166525 DOI: 10.7150/jca.16551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/18/2016] [Indexed: 01/22/2023] Open
Abstract
Comprehensive characterization of individual patients' tumour is important to realize personalized medicine. Here, we investigate to identify subsets that benefit from capecitabine plus RAD001 in advanced gastric cancer (GC) patients by comprehensive high-throughput genomic analysis (nCounter assay). Archival tumour tissue blocks, if possible, were collected at phase II trial of capecitabine plus RAD001 in 47 refractory GC patients (at clinicaltrials.gov NCT#01099527). A total of 42 formalin-fixed, paraffin-embedded (FFPE) tumour samples were available for nanostring based-multigene Assay. An nCounter assay of 519 kinase panels has been used. We performed correlation analyses between expression levels of kinase genes and response for capecitabine plus RAD001. Among 42 patients with An nCounter assay of 519 kinase panels, 4 patients achieved confirmed partial response and 15 patients revealed stable disease, resulting in an overall response rate (ORR) of 9.5%. No difference in ORR was observed in terms of gender, performance status, primary tumour site, gastric resection, histologic subtype, Lauren classification, No. of metastatic site and No. of chemotherapy. In subgroups with response for capecitabine plus RAD001, there is significant overexpression of 6 genes among 519 kinase gene such as EPHA2 (P = 0.0025), PIM1 (P = 0.0031), KSR1 (P = 0.0033), and EIF2AK4 (P = 0.0046) that are related to the activation of mTOR signalling. This study is first report that investigated to identify biomarkers predictive of the response for RAD001 containing treatment in refractory GC patients, by comprehensive high-throughput genomic analysis (nCounter assay).
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Affiliation(s)
- Hansang Lee
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jeeyun Lee
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea;; Gastric Cancer Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Insuk Sohn
- Samsung Cancer Research Institute, Seoul, Korea
| | - Se Hoon Park
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea;; Gastric Cancer Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Joon Oh Park
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea;; Gastric Cancer Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Young Suk Park
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea;; Gastric Cancer Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyoung-Mee Kim
- Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Won Ki Kang
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea;; Gastric Cancer Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Seung Tae Kim
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea;; Gastric Cancer Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Chen L, Zhang Y, Li D, Zhang N, Liu R, Han B, Wei C, Liu H, Xu X, Hao J. Everolimus ( RAD001) ameliorates vascular cognitive impairment by regulating microglial function via the mTORC1 signaling pathway. J Neuroimmunol 2016; 299:164-171. [PMID: 27725116 DOI: 10.1016/j.jneuroim.2016.09.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/05/2016] [Accepted: 09/12/2016] [Indexed: 12/14/2022]
Abstract
Vascular dementia (VaD) is a widely prevalent and devastating disease. Despite the tremendous complexity that limits understanding of the pathophysiology of VaD, microglial dysfunction has been attributed, in part, to immune microenviroment disorder and finally leads to cognitive deficits. Considered the mammalian target of rapamycin complex 1 (mTORC1) is a key player in regulation of glial function, our work focused on whether the mTOR inhibitor everolimus (RAD001) could overcome the destructive microglial function, change the phenotype and ameliorate cognitive decline induced by chronic cerebral hypoperfusion. Strikingly, the results suggest that inhibition of the mTORC1 activity by RAD001 ameliorates VaD by restoring microglia's M1/M2 balance. Therefore, RAD001 may have promise as a therapy for VaD disease.
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Affiliation(s)
- Li Chen
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China; Department of Neurology, Tianjin Huanhu Hospital, Tianjin 300060, China
| | - Yanjun Zhang
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Daojing Li
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Nong Zhang
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Ruiqiong Liu
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Bin Han
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Changjuan Wei
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Haijie Liu
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Xiaolin Xu
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin 300060, China
| | - Junwei Hao
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
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Lui A, New J, Ogony J, Thomas S, Lewis-Wambi J. Everolimus downregulates estrogen receptor and induces autophagy in aromatase inhibitor-resistant breast cancer cells. BMC Cancer 2016; 16:487. [PMID: 27421652 PMCID: PMC4947349 DOI: 10.1186/s12885-016-2490-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/30/2016] [Indexed: 01/12/2023] Open
Abstract
Background mTOR inhibition of aromatase inhibitor (AI)-resistant breast cancer is currently under evaluation in the clinic. Everolimus/RAD001 (Afinitor®) has had limited efficacy as a solo agent but is projected to become part of combination therapy for AI-resistant breast cancer. This study was conducted to investigate the anti-proliferative and resistance mechanisms of everolimus in AI-resistant breast cancer cells. Methods In this study we utilized two AI-resistant breast cancer cell lines, MCF-7:5C and MCF-7:2A, which were clonally derived from estrogen receptor positive (ER+) MCF-7 breast cancer cells following long-term estrogen deprivation. Cell viability assay, colony formation assay, cell cycle analysis and soft agar anchorage-independent growth assay were used to determine the efficacy of everolimus in inhibiting the proliferation and tumor forming potential of MCF-7, MCF-7:5C, MCF-7:2A and MCF10A cells. Confocal microscopy and transmission electron microscopy were used to evaluate LC3-II production and autophagosome formation, while ERE-luciferase reporter, Western blot, and RT-PCR analyses were used to assess ER expression and transcriptional activity. Results Everolimus inhibited the proliferation of MCF-7:5C and MCF-7:2A cells with relatively equal efficiency to parental MCF-7 breast cancer cells. The inhibitory effect of everolimus was due to G1 arrest as a result of downregulation of cyclin D1 and p21. Everolimus also dramatically reduced estrogen receptor (ER) expression (mRNA and protein) and transcriptional activity in addition to the ER chaperone, heat shock protein 90 protein (HSP90). Everolimus restored 4-hydroxy-tamoxifen (4OHT) sensitivity in MCF-7:5C cells and enhanced 4OHT sensitivity in MCF-7 and MCF-7:2A cells. Notably, we found that autophagy is one method of everolimus insensitivity in MCF-7 breast cancer cell lines. Conclusion This study provides additional insight into the mechanism(s) of action of everolimus that can be used to enhance the utility of mTOR inhibitors as part of combination therapy for AI-resistant breast cancer. Electronic supplementary material The online version of this article (doi:10.1186/s12885-016-2490-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Asona Lui
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,The University of Kansas Cancer Center, Kansas City, KS, 66160, USA
| | - Jacob New
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,The University of Kansas Cancer Center, Kansas City, KS, 66160, USA
| | - Joshua Ogony
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,The University of Kansas Cancer Center, Kansas City, KS, 66160, USA
| | - Sufi Thomas
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Otolaryngology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,The University of Kansas Cancer Center, Kansas City, KS, 66160, USA
| | - Joan Lewis-Wambi
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA. .,The University of Kansas Cancer Center, Kansas City, KS, 66160, USA.
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Evangelisti C, Bernasconi P, Cavalcante P, Cappelletti C, D'Apice MR, Sbraccia P, Novelli G, Prencipe S, Lemma S, Baldini N, Avnet S, Squarzoni S, Martelli AM, Lattanzi G. Modulation of TGFbeta 2 levels by lamin A in U2-OS osteoblast-like cells: understanding the osteolytic process triggered by altered lamins. Oncotarget 2015; 6:7424-37. [PMID: 25823658 DOI: 10.18632/oncotarget.3232] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 01/28/2015] [Indexed: 01/17/2023] Open
Abstract
Transforming growth factor beta (TGFbeta) plays an essential role in bone homeostasis and deregulation of TGFbeta occurs in bone pathologies. Patients affected by Mandibuloacral Dysplasia (MADA), a progeroid disease linked to LMNA mutations, suffer from an osteolytic process. Our previous work showed that MADA osteoblasts secrete excess amount of TGFbeta 2, which in turn elicits differentiation of human blood precursors into osteoclasts. Here, we sought to determine how altered lamin A affects TGFbeta signaling. Our results show that wild-type lamin A negatively modulates TGFbeta 2 levels in osteoblast-like U2-OS cells, while the R527H mutated prelamin A as well as farnesylated prelamin A do not, ultimately leading to increased secretion of TGFbeta 2. TGFbeta 2 in turn, triggers the Akt/mTOR pathway and upregulates osteoprotegerin and cathepsin K. TGFbeta 2 neutralization rescues Akt/mTOR activation and the downstream transcriptional effects, an effect also obtained by statins or RAD001 treatment. Our results unravel an unexpected role of lamin A in TGFbeta 2 regulation and indicate rapamycin analogs and neutralizing antibodies to TGFbeta 2 as new potential therapeutic tools for MADA.
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Lin JF, Lin YC, Yang SC, Tsai TF, Chen HE, Chou KY, Hwang TIS. Autophagy inhibition enhances RAD001-induced cytotoxicity in human bladder cancer cells. Drug Des Devel Ther 2016; 10:1501-13. [PMID: 27143856 PMCID: PMC4841413 DOI: 10.2147/dddt.s95900] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Background Mammalian target of rapamycin (mTOR), involved in PI3K/AKT/mTOR pathway, is known to play a central role in regulating the growth of cancer cells. The PI3K/AKT/mTOR pathway enhances tumor survival and proliferation through suppressing autophagy, which sustains energy homeostasis by collecting and recycling cellular components under stress conditions. Conversely, inhibitors of the mTOR pathway such as RAD001 induce autophagy, leading to promotion of tumor survival and limited antitumor efficacy. We thus hypothesized that the use of autophagy inhibitor in combination with mTOR inhibition improves the cytotoxicity of mTOR inhibitors in bladder cancer. Materials and methods The cytotoxicity of RT4, 5637, HT1376, and T24 human bladder cancer cells treated with RAD001 alone or combined with autophagy inhibitors (3-methyladenine (3-MA), bafilomycin A1 (Baf A1), chloroquine, or hydroxychloroquine) was assessed using the WST-8 cell viability kit. The autophagy status in cells was analyzed by the detection of microtubule-associated light chain 3 form II (LC3-II), using immunofluorescent staining and Western blot. Acidic vesicular organelle (AVO) formation in treated cells was determined by acridine orange vital staining. Inhibition of mTOR pathway by RAD001 was monitored by using a homemade quantitative polymerase chain reaction gene array, while phospho-mTOR was detected using Western blot. Induced apoptosis was determined by measurement of caspase 3/7 activity and DNA fragmentation in cells after treatment. Results Advanced bladder cancer cells (5637, HT1376, and T24) were more resistant to RAD001 than RT4. Autophagy flux detected by the expression of LC3-II showed RAD001-induced autophagy. AVO formation was detected in cells treated with RAD001 and was inhibited by the addition of 3-MA or Baf A1. Cotreatment of RAD001 with autophagy inhibitors further reduced cell viability and induced apoptosis in bladder cancer cells. Conclusion Our results indicate that simultaneous inhibition of the mTOR and autophagy pathway significantly enhances apoptosis, and it is suggested to be a new therapeutic paradigm for the treatment of bladder cancer.
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Affiliation(s)
- Ji-Fan Lin
- Central Laboratory, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
| | - Yi-Chia Lin
- Division of Urology, Department of Surgery, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; Division of Urology, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Shan-Che Yang
- Central Laboratory, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
| | - Te-Fu Tsai
- Division of Urology, Department of Surgery, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; Division of Urology, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Hung-En Chen
- Division of Urology, Department of Surgery, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
| | - Kuang-Yu Chou
- Division of Urology, Department of Surgery, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; Division of Urology, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Thomas I-Sheng Hwang
- Division of Urology, Department of Surgery, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; Division of Urology, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan; Department of Urology, Taipei Medical University, Taipei, Taiwan
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Das K, Chan XB, Epstein D, Te Teh B, Kim KM, Kim ST, Park SH, Kang WK, Rozen S, Lee J, Tan P. NanoString expression profiling identifies candidate biomarkers of RAD001 response in metastatic gastric cancer. ESMO Open 2016; 1:e000009. [PMID: 27843583 PMCID: PMC5070203 DOI: 10.1136/esmoopen-2015-000009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/15/2016] [Accepted: 01/19/2016] [Indexed: 12/25/2022] Open
Abstract
Background Gene expression profiling has contributed greatly to cancer research. However, expression-driven biomarker discovery in metastatic gastric cancer (mGC) remains unclear. A gene expression profile predicting RAD001 response in refractory GC was explored in this study. Methods Total RNA isolated from 54 tumour specimens from patients with mGC, prior to RAD001 treatment, was analysed via the NanoString nCounter gene expression assay. This assay targeted 477 genes representing 10 different GC-related oncogenic signalling and molecular subtype-specific expression signatures. Gene expression profiles were correlated with patient clinicopathological variables. Results NanoString data confirmed similar gene expression profiles previously identified by microarray analysis. Signature I with 3 GC subtypes (mesenchymal, metabolic and proliferative) showed approximately 90% concordance where the mesenchymal and proliferative subtypes were significantly associated with signet ring cell carcinoma and the WHO classified tubular adenocarcinoma GC, respectively (p=0.042). Single-gene-level correlations with patient clinicopathological variables showed strong associations between FHL1 expression (mesenchymal subtype) and signet ring cell carcinoma, and NEK2, OIP5, PRC1, TPX2 expression (proliferative subtype) with tubular adenocarcinoma (adjusted p<0.05). Increased BRCA2 (p=0.040) and MMP9 (p=0.045) expression was significantly associated with RAD001 good response and longer progression-free survival outcome (BRCA2, p=0.012, HR 0.370 95% CI (0.171 to 0.800); MMP9, p=0.010, HR 0.359 95% CI (0.166 to 0.779)). In contrast, increased BTC (p=0.035) expression was significantly associated with RAD001 poor response and poor progression-free survival (p=0.031, HR 2.336 95% CI (1.079 to 5.059) by univariate Cox regression analysis. Conclusions Microarray results are highly reproducible with NanoString nCounter gene expression profiling. Additionally, BRCA2 and MMP9 expression are potential predictive biomarkers for good response in RAD001-treated mGC.
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Affiliation(s)
- Kakoli Das
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School.
| | - Xiu Bin Chan
- Genome Institute of Singapore, Biopolis, Singapore
| | - David Epstein
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School
| | - Binan Te Teh
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School; Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore; Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Kyoung-Mee Kim
- Department of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Seung Tae Kim
- Department of Medicine, Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Se Hoon Park
- Department of Medicine, Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Won Ki Kang
- Department of Medicine, Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Steve Rozen
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School
| | - Jeeyun Lee
- Department of Medicine, Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Patrick Tan
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School; Genome Institute of Singapore, Biopolis, Singapore; Cancer Science Institute of Singapore, National University of Singapore, Singapore
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Abstract
This study aimed to investigate the correlations of stearoyl-coenzyme A desaturase 1 (SCD-1) with clear cell renal cell carcinoma (ccRCC) severity and PI3K-AKT-mTOR signaling pathway. From 2004 to 2006, tumor tissue and normal pericarcinomatous tissue from ccRCC samples were collected from ccRCC patients at Renji Hospital of Shanghai Jiaotong University. The expression of SCD-1 in the collected ccRCC samples and four cell lines (A498, 769-P, 786-O, and CAKI) was detected by Western blot. The correlation between SCD-1 expression and ccRCC severity was also analyzed by immunohistochemistry. Stable 786-O and 769-P ccRCC cells expressing SCD-1 short hairpin RNA (shRNA) were constructed, and the expression of proteins in the PI3K-AKT-mTOR signaling pathway was also detected. Finally, the inhibitory effect of PI3K-AKT-mTOR inhibitors (PI103, MK2206, rapamycin, AZD8055, and RAD001) on ccRCC cells stably expressing SCD-1 shRNA was also measured. Higher SCD-1 expression level was observed in ccRCC tissues compared with normal tissues. SCD-1 expression level was the highest in 786-O. SCD-1 expression was positively correlated with the tumor-node-metastasis (TNM) stage, grade of tumor cells, and lymphatic metastasis. There were no changes in the expression of AKT, ERK, PI3K, and PDK1. Significant differences were observed in the expression of p-AKT (at the Ser473 and Thr308 site), p-ERK, and two mTOR downstream molecules (4E-BP1 and p-P70S6K1) in cells stably expressing SCD-1 shRNA. PI103 and AZD8055 could enhance the inhibitory effect of SCD-1 interference on proliferation and migration of 786-O and 769-P cells. AZD8055 is recommended for the combined ccRCC treatment with shRNA interference.
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Affiliation(s)
- Hui Wang
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, No. 1630 Dongfang Road, Shanghai, 200127, China
| | - Yujian Zhang
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, No. 1630 Dongfang Road, Shanghai, 200127, China
| | - Yongning Lu
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, No. 1630 Dongfang Road, Shanghai, 200127, China
| | - Jiajia Song
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, No. 1630 Dongfang Road, Shanghai, 200127, China
| | - Min Huang
- Division of Antitumor Pharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Jin Zhang
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, No. 1630 Dongfang Road, Shanghai, 200127, China.
| | - Yiran Huang
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, No. 1630 Dongfang Road, Shanghai, 200127, China.
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Hsuan SW, Chyau CC, Hung HY, Chen JH, Chou FP. The induction of apoptosis and autophagy by Wasabia japonica extract in colon cancer. Eur J Nutr 2015; 55:491-503. [PMID: 25720497 DOI: 10.1007/s00394-015-0866-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 02/18/2015] [Indexed: 12/19/2022]
Abstract
PURPOSE Wasabia japonica (wasabi) has been shown to exhibit properties of detoxification, anti-inflammation and the induction of apoptosis in cancer cells. This study aimed to investigate the molecular mechanism of the cytotoxicity of wasabi extract (WE) in colon cancer cells to evaluate the potential of wasabi as a functional food for chemoprevention. METHODS Colo 205 cells were treated with different doses of WE, and the cytotoxicity was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. Apoptosis and autophagy were detected by 4',6-diamidino-2-phenylindole, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbo-yanine iodide and staining for acidic vascular organelles (AVOs), along with Western blotting. RESULTS The results demonstrated that WE induced the extrinsic pathway and mitochondrial death machinery through the activation of TNF-α, Fas-L, caspases, truncated Bid and cytochrome C. WE also induced autophagy by decreasing the phosphorylation of Akt and mTOR and promoting the expression of microtubule-associated protein 1 light chain 3-II and AVO formation. An in vivo xenograft model verified that tumor growth was delayed by WE treatment. CONCLUSION Our studies revealed that WE exhibits anti-colon cancer properties through the induction of apoptosis and autophagy. These results provide support for the application of WE as a chemopreventive functional food and as a prospective treatment of colon cancer.
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Affiliation(s)
- Shu-Wen Hsuan
- Institute of Biochemistry and Biotechnology, Medical College, Chung Shan Medical University, Taichung, Taiwan
| | - Charng-Cherng Chyau
- Research Institute of Biotechnology, Hung Kuang University, Taichung, Taiwan
| | - Hsiao-Yu Hung
- Institute of Biochemistry and Biotechnology, Medical College, Chung Shan Medical University, Taichung, Taiwan
| | - Jing-Hsien Chen
- School of Nutrition, Chung Shan Medical University, Taichung, Taiwan. .,Chung Shan Medical University, No. 110, Sec. 1, Jiangou N. Rd., South Dist., Taichung City, 402, Taiwan.
| | - Fen-Pi Chou
- Institute of Biochemistry and Biotechnology, Medical College, Chung Shan Medical University, Taichung, Taiwan. .,Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan. .,Chung Shan Medical University, No. 110, Sec. 1, Jiangou N. Rd., South Dist., Taichung City, 402, Taiwan.
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Juengel E, Kim D, Makarević J, Reiter M, Tsaur I, Bartsch G, Haferkamp A, Blaheta RA. Molecular analysis of sunitinib resistant renal cell carcinoma cells after sequential treatment with RAD001 (everolimus) or sorafenib. J Cell Mol Med 2014; 19:430-41. [PMID: 25444514 PMCID: PMC4407590 DOI: 10.1111/jcmm.12471] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 09/10/2014] [Indexed: 11/30/2022] Open
Abstract
Sequential application of target drugs is standard procedure after renal cell carcinoma (RCC) patients develop resistance. To optimize the sequence, antitumour effects of the mTOR inhibitor RAD001 or the tyrosine kinase inhibitor (TKI) sorafenib on RCC cells with acquired resistance to the TKI sunitinib was evaluated. RCC cells were exposed to 1 μM sunitinib for 24 hrs (as control) and for 8 weeks (to induce resistance) and then switched to RAD001 (5 nM) or sorafenib (5 μM) for a further 8 weeks. Tumour cell growth, cell cycle progression, cell cycle regulating proteins and intracellular signalling were then investigated. Short-term application of sunitinib (24 hrs) induced cell growth blockade with accumulation in the G2/M phase. RCC cells became resistant to sunitinib after 8 weeks, demonstrated by accelerated cell growth along with enhanced cdk1, cdk2, loss of p27, activation of Akt, Rictor and Raptor. Switching to sorafenib only slightly reduced growth of the sunitinib resistant RCC cells and molecular analysis indicated distinct cross-resistance. In contrast, full response was achieved when the cancer cells were treated with RAD001. p19 and p27 strongly increased, phosphorylated Akt, Rictor and Raptor decreased and the tumour cells accumulated in G0/G1. It is concluded that an mTOR-inhibitor for second-line therapy could be the strategy of choice after first-line sunitinib failure.
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Affiliation(s)
- Eva Juengel
- Department of Urology, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany
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Monsalves E, Juraschka K, Tateno T, Agnihotri S, Asa SL, Ezzat S, Zadeh G. The PI3K/AKT/mTOR pathway in the pathophysiology and treatment of pituitary adenomas. Endocr Relat Cancer 2014; 21:R331-44. [PMID: 25052915 DOI: 10.1530/erc-14-0188] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pituitary adenomas are common intracranial neoplasms. Patients with these tumors exhibit a wide range of clinically challenging problems, stemming either from results of sellar mass effect in pituitary macroadenoma or the diverse effects of aberrant hormone production by adenoma cells. While some patients are cured/controlled by surgical resection and/or medical therapy, a proportion of patients exhibit tumors that are refractory to current modalities. New therapeutic approaches are needed for these patients. Activation of the AKT/phophotidylinositide-3-kinase pathway, including mTOR activation, is common in human neoplasia, and a number of therapeutic approaches are being employed to neutralize activation of this pathway in human cancer. This review examines the role of this pathway in pituitary tumors with respect to tumor biology and its potential role as a therapeutic target.
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Affiliation(s)
- Eric Monsalves
- Institute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, CanadaInstitute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, Canada
| | - Kyle Juraschka
- Institute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, Canada
| | - Toru Tateno
- Institute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, Canada
| | - Sameer Agnihotri
- Institute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, Canada
| | - Sylvia L Asa
- Institute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, Canada
| | - Shereen Ezzat
- Institute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, CanadaInstitute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, CanadaInstitute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, Canada
| | - Gelareh Zadeh
- Institute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, CanadaInstitute of Medical ScienceDepartment of Medical BiophysicsUniversity of Toronto, Toronto, Ontario, CanadaDivision of NeurosurgeryToronto Western Hospital, 399 Bathurst Street, 4W-439, Toronto, Ontario, Canada M5T 2S8Ontario Cancer InstitutePrincess Margaret Hospital, Toronto, Ontario, CanadaEndocrine Oncology Site GroupPrincess Margaret Hospital, Toronto, Ontario, CanadaDepartment of Laboratory Medicine and PathobiologyUniversity of Toronto, Toronto, Ontario, Canada
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Bison SM, Pool SE, Koelewijn SJ, van der Graaf LM, Groen HC, Melis M, de Jong M. Peptide receptor radionuclide therapy (PRRT) with [(177)Lu-DOTA(0),Tyr(3)]octreotate in combination with RAD001 treatment: further investigations on tumor metastasis and response in the rat pancreatic CA20948 tumor model. EJNMMI Res 2014; 4:21. [PMID: 24995150 PMCID: PMC4070081 DOI: 10.1186/s13550-014-0021-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 04/01/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Previously, we reported on the unexpected development of distant metastases in the subcutaneous rat pancreas CA20948 tumor model after 4.5 weeks of treatment with RAD001-only or in combination with [(177)Lu-DOTA(0),Tyr(3)]octreotate ((177)Lu-DOTATATE) (Cancer Res. 73:12-8, 2013). Moreover, the combination therapy was less effective compared to (177)Lu-DOTATATE-only. In the current study, we address the following questions: (1) Why was the combination therapy less effective? Is (177)Lu-DOTATATE tumor uptake affected by pretreatment with RAD001? (2) Could sudden cessation of RAD001 therapy cause the development of distant metastases? (3) Is (177)Lu-DOTATATE an effective treatment option for these metastases? METHODS Lewis rats (HanHsd or SsNHsd substrain with a slight difference in immune response) bearing subcutaneous CA20948 tumors were treated with either 125 or 275 MBq (177)Lu-DOTATATE, RAD001, or their combination. RAD001 was given twice a week for 4.5 or 12 weeks, whereas (177)Lu-DOTATATE was given as a single injection. When combined, RAD001 was started either 3 days prior to or 3 days post administration of (177)Lu-DOTATATE. SPECT/CT was performed to quantify (177)Lu-DOTATATE tumor uptake. Where indicated, primary tumors were surgically removed when tumor size is >6,000 mm(3) to enable monitoring for possible metastasis. If metastases were suspected, an (111)In-DTPA-octreotide SPECT/CT scan was performed. Seven rats with metastases were treated with 400 MBq (177)Lu-DOTATATE. RESULTS Lu-DOTATATE tumor uptake was not significantly affected by RAD001 pretreatment. The occurrence of metastases after RAD001 treatment was not dose dependent in the dose range tested, nor was it related to the duration of RAD001 treatment. In the experiment in which the LEW/SsNsd substrain was used, only 12.5% of RAD001-treated rats showed complete response (CR), compared to 50% tumor regression in the control group. Re-treatment with a high dose of (177)Lu-DOTATATE resulted in CR in only two out of seven animals. CONCLUSION Less effective anti-tumor effects after the combination of RAD001 + (177)Lu-DOTATATE could not be explained by reduced (177)Lu-DOTATATE tumor uptake after RAD001. Our current data support RAD001-induced immune suppression as the reason for this observation. No evidence was found that cessation of RAD001 treatment caused development of metastases. Metastases appeared to be less sensitive to (177)Lu-DOTATATE treatment than primary tumors.
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Affiliation(s)
- Sander M Bison
- Department of Nuclear Medicine, Erasmus MC, Postbus 2040, Rotterdam 3000, CA, the Netherlands ; Department of Radiology, Erasmus MC, Rotterdam 3000, CA, the Netherlands ; Department of Medical Informatics, Erasmus MC, Rotterdam 3000, CA, the Netherlands
| | - Stefan E Pool
- Department of Nuclear Medicine, Erasmus MC, Postbus 2040, Rotterdam 3000, CA, the Netherlands
| | - Stuart J Koelewijn
- Department of Nuclear Medicine, Erasmus MC, Postbus 2040, Rotterdam 3000, CA, the Netherlands
| | - Linda M van der Graaf
- Department of Nuclear Medicine, Erasmus MC, Postbus 2040, Rotterdam 3000, CA, the Netherlands
| | - Harald C Groen
- Department of Nuclear Medicine, Erasmus MC, Postbus 2040, Rotterdam 3000, CA, the Netherlands ; Department of Radiology, Erasmus MC, Rotterdam 3000, CA, the Netherlands
| | - Marleen Melis
- Department of Nuclear Medicine, Erasmus MC, Postbus 2040, Rotterdam 3000, CA, the Netherlands
| | - Marion de Jong
- Department of Nuclear Medicine, Erasmus MC, Postbus 2040, Rotterdam 3000, CA, the Netherlands ; Department of Radiology, Erasmus MC, Rotterdam 3000, CA, the Netherlands
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Moolthiya P, Tohtong R, Keeratichamroen S, Leelawat K. Role of mTOR inhibitor in cholangiocarcinoma cell progression. Oncol Lett 2014; 7:854-860. [PMID: 24527093 PMCID: PMC3919862 DOI: 10.3892/ol.2014.1799] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 11/29/2013] [Indexed: 12/29/2022] Open
Abstract
Cholangiocarcinoma (CCA) is a lethal malignancy of the biliary epithelium. CCA is resistant to currently available chemotherapy; therefore, new drugs as well as new molecular targets must be identified for the development of an effective treatment for CCA. The present study showed that RAD001 (everolimus), a derivative of rapamycin and an orally bioavailable mammalian target of rapamycin (mTOR) inhibitor, exhibits cytotoxic and antimetastatic effects in a CCA cell line, RMCCA-1. Treatment with low concentrations of RAD001 resulted in a significant reduction of in vitro invasion and migration of RMCCA-1, concomitant with a reduction of filopodia and alteration of the actin cytoskeleton. Although, matrix metalloproteinase-9 and -14 activities were unaltered. However, at high concentrations, RAD001 exhibited cytotoxic effects, reducing cell proliferation and inducing apoptotic cell death. Overall, RAD001 exhibits multiple effects mediated by the inhibition of the mTOR, which may serve as a promising agent for the treatment of CCA.
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Affiliation(s)
- Penpak Moolthiya
- Department of Biochemistry, Faculty of Science, Mahidol University, Rajathevi, Bangkok 10400, Thailand
| | - Rutaiwan Tohtong
- Department of Biochemistry, Faculty of Science, Mahidol University, Rajathevi, Bangkok 10400, Thailand
| | - Siriporn Keeratichamroen
- Department of Molecular Medicine, Faculty of Science, Mahidol University, Rajathevi, Bangkok 10400, Thailand
| | - Kawin Leelawat
- Department of Surgery, Rajavithi Hospital, Rajathevi, Bangkok 10400, Thailand
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Ewald F, Grabinski N, Grottke A, Windhorst S, Nörz D, Carstensen L, Staufer K, Hofmann BT, Diehl F, David K, Schumacher U, Nashan B, Jücker M. Combined targeting of AKT and mTOR using MK-2206 and RAD001 is synergistic in the treatment of cholangiocarcinoma. Int J Cancer 2013; 133:2065-76. [PMID: 23588885 DOI: 10.1002/ijc.28214] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 03/14/2013] [Indexed: 01/12/2023]
Abstract
Cholangiocarcinoma (CCA) is a rare, but devastating disease arising from the epithelium of intrahepatic and extrahepatic bile ducts. There are neither effective systemic therapies nor satisfying treatment options for inoperable CCA. Histopathological and biochemical studies of CCA show frequent dysregulation of the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin (mTOR) pathway. Therefore, we investigated the efficacy of the mTOR inhibitor RAD001 and the impact of AKT signaling following mTOR inhibition in the treatment of CCA. RAD001 significantly inhibits proliferation of CCA cell lines, however, a concentration-dependent and isoform specific feedback activation of the three AKT isoforms (AKT1, AKT2 and AKT3) was observed after mTOR inhibition. As activation of AKT might limit the RAD001-mediated anti-tumor effect, the efficacy of combined mTOR and AKT inhibition was investigated using the allosteric AKT inhibitor MK-2206. Our results show that inhibition of AKT potentiates the efficacy of mTOR inhibition both in vitro and in a xenograft mouse model in vivo. Mechanistically, the antiproliferative effect of the pan-AKT inhibitor MK2206 in the CCA cell line TFK-1 was due to inhibition of AKT1 and AKT2, because knockdown of either AKT1 or AKT2, but not AKT3, showed a synergistic reduction of cell proliferation in combination with mTOR treatment. Finally, using an AKT isoform specific in vitro kinase assay, enzymatic activity of each of the three AKT isoforms was detected in all tissue samples from CCA patients, analyzed. In summary, our preclinical data suggest that combined targeting of mTOR and AKT using RAD001 and MK-2206 might be a new, effective strategy for the treatment of CCA.
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Affiliation(s)
- Florian Ewald
- Department of Hepatobiliary and Transplant Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Josset E, Burckel H, Noël G, Bischoff P. The mTOR inhibitor RAD001 potentiates autophagic cell death induced by temozolomide in a glioblastoma cell line. Anticancer Res 2013; 33:1845-1851. [PMID: 23645729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have studied the consequences of the combination of the mammalian target of rapamycin (mTOR) inhibitor RAD001 and temozolomide on the growth and cell death of the glioblastoma cell line U-87 in vitro. A progressive decrease of cell proliferation was recorded with increasing concentrations of temozolomide, which was markedly reinforced and prolonged by the addition of RAD001. While this combination treatment resulted in only a low level of apoptosis, it led to a pronounced enhancement of autophagic cell death. When combined with γ-ray irradiation, a significant reinforcement of the overall cytotoxicity was obtained, suggesting the efficacy of such a multipronged approach for the treatment of glioblastoma. RAD001 strongly contributes to the reinforcement of temozolomide-induced autophagy, which appears to represent a major form of cell death in glioblastoma. The association of such combined chemotherapies with radiotherapy could be useful for the management of these hard-to-treat malignancies.
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Affiliation(s)
- Elodie Josset
- Université de Strasbourg, Centre régional de Lutte contre le Cancer Paul Strauss, 3 rue de la Porte de l'Hôpital, F-67085 Strasbourg Cedex, France
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Werner D, Atmaca A, Pauligk C, Pustowka A, Jäger E, Al-Batran SE. Phase I study of everolimus and mitomycin C for patients with metastatic esophagogastric adenocarcinoma. Cancer Med 2013; 2:325-33. [PMID: 23930209 PMCID: PMC3699844 DOI: 10.1002/cam4.77] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/05/2013] [Accepted: 03/07/2013] [Indexed: 01/20/2023] Open
Abstract
This study aimed at determining the recommended dose of the mammalian target of rapamycin inhibitor everolimus in combination with mitomycin C (MMC) in patients with previously treated metastatic esophagogastric cancer. In this phase I trial, patients received escalated doses of oral everolimus (5, 7.5, and 10 mg/day) in combination with intravenous MMC 5 mg/m2 every 3 weeks. Endpoints were the dose-limiting toxicity (DLT), safety, and response rates. Tumor tissues were tested for HER2-status and mutations in the PTEN, PIK3CA, AKT1, CTNNB1, and E-cadherin type 1 genes. Sixteen patients (12 male, four female) with gastric/gastroesophageal junction cancer were included. All patients were previously treated with a platinum-based chemotherapy. Treatment cohorts were: 5 mg/day, three patients; 7.5 mg/day, three patients; and 10 mg/day, 10 patients. No DLTs occurred during dose escalation. Most frequent grade 3 toxicities were leukopenia (18.8%) and neutropenia (18.8%). All other grade 3 toxicities were below 10%. No grade 4 toxicities occurred. Three (18.8%) patients experienced partial responses and four patients had stable disease (SD). Antitumor activity according to Response Evaluation Criteria In Solid Tumors (RECIST)-criteria was highest in the 10 mg/day cohort. No associations between HER2-status or detected mutations and response were observed. The recommended dose of everolimus combined with MMC is 10 mg/day. Encouraging signs of antitumor activity were seen (http://www.ClinicalTrials.gov; Clinical trial registration number: NCT01042782).
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Affiliation(s)
- Dominique Werner
- Krankenhaus Nordwest, UCT-University Cancer Center, Frankfurt am Main, Germany
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Abstract
Pancreatic neuroendocrine tumors (PanNETs) are frequently diagnosed at unresectable stage and remain a medical challenge. Everolimus (RAD001, Afinitor®, Novartis, Basel, Switzerland), an orally administered inhibitor of mammalian target of rapamycin (mTOR), was recently approved by the Food and Drug Administration to treat patients with advanced PanNETs. This review will examine the mechanism of action of everolimus, the function of mTOR and its inhibition, PanNETs and the mTOR pathway, and clinical trials of everolimus in PanNETs. Future investigations will focus on everolimus combination therapy to treat PanNETs and the discovery of predictive biomarkers for response to everolimus.
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Affiliation(s)
- Putao Cen
- Division of Oncology, Department of Internal Medicine, University of Texas Health Science Center at Houston (Medical School), Houston, TX, USA
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Vasconcelos-Nóbrega C, Pinto-Leite R, Arantes-Rodrigues R, Ferreira R, Brochado P, Cardoso ML, Palmeira C, Salvador A, Guedes-Teixeira CI, Colaço A, Palomino LF, Lopes C, Santos L, Oliveira PA. In vivo and in vitro effects of RAD001 on bladder cancer. Urol Oncol 2011; 31:1212-21. [PMID: 22169072 DOI: 10.1016/j.urolonc.2011.11.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 10/24/2011] [Accepted: 11/02/2011] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To evaluate the influence of Everolimus (RAD001) on chemically induced urothelial lesions in mice and its influence on in vitro human bladder cancer cell lines. METHODS ICR male mice were given N-butyl-N-(4-hydroxybutyl) nitrosamine in drinking water for a period of 12 weeks. Subsequently, RAD001 was administered via oral gavage, for 6 weeks. At the end of the experiment, all the animals were sacrificed and tumor development was determined by means of histopathologic evaluation; mammalian target of rapamycin (mTOR) expressivity was evaluated by immunohistochemistry. Three human bladder cancer cell lines (T24, HT1376, and 5637) were treated using a range of RAD001 concentrations. MTT assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry were used to assess cell proliferation, apoptosis index, and cell cycle analysis, respectively. Immunoblotting analysis of 3 cell line extracts using mTOR and Akt antibodies was performed in order to study the expression of Akt and mTOR proteins and their phosphorylated forms. RESULTS The incidence of urothelial lesions in animals treated with RAD001 was similar to those animals not treated. RAD001 did not block T24 and HT1376 cell proliferation or induce apoptosis. A reduction in cell proliferation rate and therefore G0/G1 phase arrest, as well as a statistically significant induction of apoptosis (P = 0.001), was only observed in the 5637 cell line. CONCLUSION RAD001 seems not to have a significant effect on chemically induced murine bladder tumors. The effect of RAD001 on tumor proliferation and apoptosis was achieved only in superficial derived bladder cancer cell line, no effect was observed in invasive cell lines.
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Sukumari-Ramesh S, Singh N, Dhandapani KM, Vender JR. mTOR inhibition reduces cellular proliferation and sensitizes pituitary adenoma cells to ionizing radiation. Surg Neurol Int 2011; 2:22. [PMID: 21427787 PMCID: PMC3050059 DOI: 10.4103/2152-7806.77029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 01/12/2011] [Indexed: 11/10/2022] Open
Abstract
Background: Pituitary adenomas are the most frequent brain tumor in adults. Although histologically benign, pituitary tumors cause significant morbidity and mortality. Neurosurgery and medical therapeutics may lessen the morbidity and mortality associated with pituitary tumors; however, these treatments are associated with significant adverse side effects. Thus, an improved understanding of pituitary adenomas at the molecular and cellular level is needed to design novel therapeutic compounds. Methods: To assess the effect of mammalian target of rapamycin (mTOR) inhibition on pituitary adenoma cells, rat GH3 or MMQ cells were treated with the clinically useful mTOR inhibitors, rapamycin or RAD001. Cellular proliferation and growth following exposure to mTOR inhibitors or radiation were assessed using biochemical methods. Results: In the present study, we observed basal activation of mTOR, downstream of constitutive Akt signaling, in rat GH3 adenoma cells. Functionally, the mTOR inhibitors, rapamycin and RAD001 (500 pM–5 nM), induced G1 growth arrest within 24 hours, an effect associated with reduced cellular proliferation. Both rapamycin and RAD001 decreased the phosphorylation of mTOR at the serine 2448, a key determinant of mTOR activity. Inhibition of mTOR also radiosensitized GH3 cells such that 2.5 Gy in combination with 500 pM rapamycin or RAD001 reduced cellular viability more effectively than 2.5 or 10 Gy alone. Conclusions: These data may support a possible therapeutic role for mTOR inhibitors in limiting the cellular proliferation and radioresistance of pituitary adenoma cells.
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