1
|
Kundu A, Khouri MG, Aryana S, Firestone GL. 1-Benzyl-indole-3-carbinol is a highly potent new small molecule inhibitor of Wnt/β-catenin signaling in melanoma cells that coordinately inhibits cell proliferation and disrupts expression of microphthalmia-associated transcription factor isoform-M. Carcinogenesis 2017; 38:1207-1217. [PMID: 29028954 DOI: 10.1093/carcin/bgx103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 09/19/2017] [Indexed: 11/15/2022] Open
Abstract
1-Benzyl-indole-3-carbinol (1-benzyl-I3C), a synthetic analogue of the crucifer-derived natural phytochemical I3C, displayed significantly wider sensitivity and anti-proliferative potency in melanoma cells than the natural compound. Unlike I3C, which targets mainly oncogenic BRAF-expressing cells, 1-benzyl-I3C effectively inhibited proliferation of melanoma cells with a more extensive range of mutational profiles, including those expressing wild-type BRAF. In both cultured melanoma cell lines and in vivo in melanoma cell-derived tumor xenografts, 1-benzyl-I3C disrupted canonical Wnt/β-catenin signaling that resulted in the downregulation of β-catenin protein levels with a concomitant increase in levels of the β-catenin destruction complex components such as glycogen synthase kinase-3β (GSK-3β) and Axin. Concurrent with the inhibition of Wnt/β-catenin signaling, 1-benzyl-I3C strongly downregulated expression of the melanoma master regulator, microphthalmia-associated transcription factor isoform-M (MITF-M) by inhibiting promoter activity through the consensus lymphoid enhancer factor-1 (LEF-1)/T-cell transcription factor (TCF) DNA-binding site. Chromatin immunoprecipitation revealed that 1-benzyl-I3C downregulated interactions of endogenous LEF-1 with the MITF-M promoter. 1-Benzyl-I3C ablated Wnt-activated LEF-1-dependent reporter gene activity in a TOP FLASH assay that was rescued by expression of a constitutively active form of the Wnt co-receptor low-density lipoprotein receptor-related protein (LRP6), indicating that 1-benzyl-I3C disrupts Wnt/β-catenin signaling at or upstream of LRP6. In oncogenic BRAF-expressing melanoma cells, combinations of 1-benzyl-I3C and Vemurafenib, a clinically employed BRAF inhibitor, showed strong anti-proliferative effects. Taken together, our observations demonstrate that 1-benzyl-I3C represents a new and highly potent indolecarbinol-based small molecule inhibitor of Wnt/β-catenin signaling that has intriguing translational potential, alone or in combination with other anti-cancer agents, to treat human melanoma.
Collapse
Affiliation(s)
- Aishwarya Kundu
- Department of Molecular and Cell Biology and the Cancer Research Laboratory, University of California at Berkeley, USA
| | - Michelle G Khouri
- Department of Molecular and Cell Biology and the Cancer Research Laboratory, University of California at Berkeley, USA
| | - Sheila Aryana
- Department of Molecular and Cell Biology and the Cancer Research Laboratory, University of California at Berkeley, USA
| | | |
Collapse
|
2
|
Quirit JG, Lavrenov SN, Poindexter K, Xu J, Kyauk C, Durkin KA, Aronchik I, Tomasiak T, Solomatin YA, Preobrazhenskaya MN, Firestone GL. Indole-3-carbinol (I3C) analogues are potent small molecule inhibitors of NEDD4-1 ubiquitin ligase activity that disrupt proliferation of human melanoma cells. Biochem Pharmacol 2016; 127:13-27. [PMID: 27979631 DOI: 10.1016/j.bcp.2016.12.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [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: 08/30/2016] [Accepted: 12/09/2016] [Indexed: 11/16/2022]
Abstract
The HECT domain-containing E3 ubiquitin ligase NEDD4-1 (Neural precursor cell Expressed Developmentally Down regulated gene 4-1) is frequently overexpressed in human cancers and displays oncogenic-like properties through the ubiquitin-dependent regulation of multiple protein substrates. However, little is known about small molecule enzymatic inhibitors of HECT domain-containing ubiquitin ligases. We now demonstrate that indole-3-carbinol (I3C), a natural anti-cancer phytochemical derived from cruciferous vegetables such as cabbage and broccoli, represents a new chemical scaffold of small molecule enzymatic inhibitors of NEDD4-1. Using in vitro ubiquitination assays, I3C, its stable synthetic derivative 1-benzyl-I3C and five novel synthetic analogues were shown to directly inhibit NEDD4-1 ubiquitination activity. Compared to I3C, which has an IC50 of 284μM, 1-benzyl-I3C was a significantly more potent NEDD4-1 enzymatic inhibitor with an IC50 of 12.3μM. Compounds 2242 and 2243, the two indolecarbinol analogues with added methyl groups that results in a more nucleophilic benzene ring π system, further enhanced potency with IC50s of 2.71μM and 7.59μM, respectively. Protein thermal shift assays that assess small ligand binding, in combination with in silico binding simulations with the crystallographic structure of NEDD4-1, showed that each of the indolecarbinol compounds bind to the purified catalytic HECT domain of NEDD4-1. The indolecarbinol compounds inhibited human melanoma cell proliferation in a manner that generally correlated with their effectiveness as NEDD4-1 enzymatic inhibitors. Taken together, we propose that I3C analogues represent a novel set of anti-cancer compounds for treatment of human melanomas and other cancers that express indolecarbinol-sensitive target enzymes.
Collapse
Affiliation(s)
- Jeanne G Quirit
- Dept. of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA, USA.
| | - Sergey N Lavrenov
- Gause Institute of New Antibiotics, B. Pirogovskaya 11, Moscow 119021, Russia.
| | - Kevin Poindexter
- Dept. of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA, USA.
| | - Janice Xu
- Dept. of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA, USA.
| | - Christine Kyauk
- Dept. of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - Kathleen A Durkin
- Molecular Graphics and Computational Facility, College of Chemistry, University of California, Berkeley, CA, USA.
| | - Ida Aronchik
- Dept. of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA, USA.
| | - Thomas Tomasiak
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA.
| | | | | | - Gary L Firestone
- Dept. of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA, USA.
| |
Collapse
|
3
|
Block KI, Gyllenhaal C, Lowe L, Amedei A, Amin ARMR, Amin A, Aquilano K, Arbiser J, Arreola A, Arzumanyan A, Ashraf SS, Azmi AS, Benencia F, Bhakta D, Bilsland A, Bishayee A, Blain SW, Block PB, Boosani CS, Carey TE, Carnero A, Carotenuto M, Casey SC, Chakrabarti M, Chaturvedi R, Chen GZ, Chen H, Chen S, Chen YC, Choi BK, Ciriolo MR, Coley HM, Collins AR, Connell M, Crawford S, Curran CS, Dabrosin C, Damia G, Dasgupta S, DeBerardinis RJ, Decker WK, Dhawan P, Diehl AME, Dong JT, Dou QP, Drew JE, Elkord E, El-Rayes B, Feitelson MA, Felsher DW, Ferguson LR, Fimognari C, Firestone GL, Frezza C, Fujii H, Fuster MM, Generali D, Georgakilas AG, Gieseler F, Gilbertson M, Green MF, Grue B, Guha G, Halicka D, Helferich WG, Heneberg P, Hentosh P, Hirschey MD, Hofseth LJ, Holcombe RF, Honoki K, Hsu HY, Huang GS, Jensen LD, Jiang WG, Jones LW, Karpowicz PA, Keith WN, Kerkar SP, Khan GN, Khatami M, Ko YH, Kucuk O, Kulathinal RJ, Kumar NB, Kwon BS, Le A, Lea MA, Lee HY, Lichtor T, Lin LT, Locasale JW, Lokeshwar BL, Longo VD, Lyssiotis CA, MacKenzie KL, Malhotra M, Marino M, Martinez-Chantar ML, Matheu A, Maxwell C, McDonnell E, Meeker AK, Mehrmohamadi M, Mehta K, Michelotti GA, Mohammad RM, Mohammed SI, Morre DJ, Muralidhar V, Muqbil I, Murphy MP, Nagaraju GP, Nahta R, Niccolai E, Nowsheen S, Panis C, Pantano F, Parslow VR, Pawelec G, Pedersen PL, Poore B, Poudyal D, Prakash S, Prince M, Raffaghello L, Rathmell JC, Rathmell WK, Ray SK, Reichrath J, Rezazadeh S, Ribatti D, Ricciardiello L, Robey RB, Rodier F, Rupasinghe HPV, Russo GL, Ryan EP, Samadi AK, Sanchez-Garcia I, Sanders AJ, Santini D, Sarkar M, Sasada T, Saxena NK, Shackelford RE, Shantha Kumara HMC, Sharma D, Shin DM, Sidransky D, Siegelin MD, Signori E, Singh N, Sivanand S, Sliva D, Smythe C, Spagnuolo C, Stafforini DM, Stagg J, Subbarayan PR, Sundin T, Talib WH, Thompson SK, Tran PT, Ungefroren H, Vander Heiden MG, Venkateswaran V, Vinay DS, Vlachostergios PJ, Wang Z, Wellen KE, Whelan RL, Yang ES, Yang H, Yang X, Yaswen P, Yedjou C, Yin X, Zhu J, Zollo M. Designing a broad-spectrum integrative approach for cancer prevention and treatment. Semin Cancer Biol 2016; 35 Suppl:S276-S304. [PMID: 26590477 DOI: 10.1016/j.semcancer.2015.09.007] [Citation(s) in RCA: 190] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 08/12/2015] [Accepted: 09/14/2015] [Indexed: 12/14/2022]
Abstract
Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are not reliant upon the same mechanisms as those which have been targeted). To address these limitations, an international task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspects of relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a wide range of high-priority targets (74 in total) that could be modified to improve patient outcomes. For these targets, corresponding low-toxicity therapeutic approaches were then suggested, many of which were phytochemicals. Proposed actions on each target and all of the approaches were further reviewed for known effects on other hallmark areas and the tumor microenvironment. Potential contrary or procarcinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixed evidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of the relationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. This novel approach has potential to be relatively inexpensive, it should help us address stages and types of cancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for future research is offered.
Collapse
Affiliation(s)
- Keith I Block
- Block Center for Integrative Cancer Treatment, Skokie, IL, United States.
| | | | - Leroy Lowe
- Getting to Know Cancer, Truro, Nova Scotia, Canada; Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, United Kingdom.
| | - Amedeo Amedei
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - A R M Ruhul Amin
- Winship Cancer Institute of Emory University, Atlanta, GA, United States
| | - Amr Amin
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Katia Aquilano
- Department of Biology, University of Rome "Tor Vergata", Rome, Italy
| | - Jack Arbiser
- Winship Cancer Institute of Emory University, Atlanta, GA, United States; Atlanta Veterans Administration Medical Center, Atlanta, GA, United States; Department of Dermatology, Emory University School of Medicine, Emory University, Atlanta, GA, United States
| | - Alexandra Arreola
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States
| | - Alla Arzumanyan
- Department of Biology, Temple University, Philadelphia, PA, United States
| | - S Salman Ashraf
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Asfar S Azmi
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States
| | - Fabian Benencia
- Department of Biomedical Sciences, Ohio University, Athens, OH, United States
| | - Dipita Bhakta
- School of Chemical and Bio Technology, SASTRA University, Thanjavur, Tamil Nadu, India
| | | | - Anupam Bishayee
- Department of Pharmaceutical Sciences, College of Pharmacy, Larkin Health Sciences Institute, Miami, FL, United States
| | - Stacy W Blain
- Department of Pediatrics, State University of New York, Downstate Medical Center, Brooklyn, NY, United States
| | - Penny B Block
- Block Center for Integrative Cancer Treatment, Skokie, IL, United States
| | - Chandra S Boosani
- Department of BioMedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
| | - Thomas E Carey
- Head and Neck Cancer Biology Laboratory, University of Michigan, Ann Arbor, MI, United States
| | - Amancio Carnero
- Instituto de Biomedicina de Sevilla, Consejo Superior de Investigaciones Cientificas, Seville, Spain
| | - Marianeve Carotenuto
- Centro di Ingegneria Genetica e Biotecnologia Avanzate, Naples, Italy; Department of Molecular Medicine and Medical Biotechnology, Federico II, Via Pansini 5, 80131 Naples, Italy
| | - Stephanie C Casey
- Stanford University, Division of Oncology, Department of Medicine and Pathology, Stanford, CA, United States
| | - Mrinmay Chakrabarti
- Department of Pathology, Microbiology, and Immunology, University of South Carolina, School of Medicine, Columbia, SC, United States
| | - Rupesh Chaturvedi
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Georgia Zhuo Chen
- Winship Cancer Institute of Emory University, Atlanta, GA, United States
| | - Helen Chen
- Department of Pediatrics, University of British Columbia, Michael Cuccione Childhood Cancer Research Program, Child and Family Research Institute, Vancouver, British Columbia, Canada
| | - Sophie Chen
- Ovarian and Prostate Cancer Research Laboratory, Guildford, Surrey, United Kingdom
| | - Yi Charlie Chen
- Department of Biology, Alderson Broaddus University, Philippi, WV, United States
| | - Beom K Choi
- Cancer Immunology Branch, Division of Cancer Biology, National Cancer Center, Goyang, Gyeonggi, Republic of Korea
| | | | - Helen M Coley
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, United Kingdom
| | - Andrew R Collins
- Department of Nutrition, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Marisa Connell
- Department of Pediatrics, University of British Columbia, Michael Cuccione Childhood Cancer Research Program, Child and Family Research Institute, Vancouver, British Columbia, Canada
| | - Sarah Crawford
- Cancer Biology Research Laboratory, Southern Connecticut State University, New Haven, CT, United States
| | - Colleen S Curran
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Charlotta Dabrosin
- Department of Oncology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Giovanna Damia
- Department of Oncology, Istituto Di Ricovero e Cura a Carattere Scientifico - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Santanu Dasgupta
- Department of Cellular and Molecular Biology, the University of Texas Health Science Center at Tyler, Tyler, TX, United States
| | - Ralph J DeBerardinis
- Children's Medical Center Research Institute, University of Texas - Southwestern Medical Center, Dallas, TX, United States
| | - William K Decker
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States
| | - Punita Dhawan
- Department of Surgery and Cancer Biology, Division of Surgical Oncology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Anna Mae E Diehl
- Department of Medicine, Duke University Medical Center, Durham, NC, United States
| | - Jin-Tang Dong
- Winship Cancer Institute of Emory University, Atlanta, GA, United States
| | - Q Ping Dou
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States
| | - Janice E Drew
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Eyad Elkord
- College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bassel El-Rayes
- Department of Hematology and Medical Oncology, Emory University, Atlanta, GA, United States
| | - Mark A Feitelson
- Department of Biology, Temple University, Philadelphia, PA, United States
| | - Dean W Felsher
- Stanford University, Division of Oncology, Department of Medicine and Pathology, Stanford, CA, United States
| | - Lynnette R Ferguson
- Discipline of Nutrition and Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Carmela Fimognari
- Dipartimento di Scienze per la Qualità della Vita Alma Mater Studiorum-Università di Bologna, Rimini, Italy
| | - Gary L Firestone
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, CA, United States
| | - Christian Frezza
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Cambridge, United Kingdom
| | - Hiromasa Fujii
- Department of Orthopedic Surgery, Nara Medical University, Kashihara, Nara, Japan
| | - Mark M Fuster
- Medicine and Research Services, Veterans Affairs San Diego Healthcare System & University of California, San Diego, CA, United States
| | - Daniele Generali
- Department of Medical, Surgery and Health Sciences, University of Trieste, Trieste, Italy; Molecular Therapy and Pharmacogenomics Unit, Azienda Ospedaliera Istituti Ospitalieri di Cremona, Cremona, Italy
| | - Alexandros G Georgakilas
- Physics Department, School of Applied Mathematics and Physical Sciences, National Technical University of Athens, Athens, Greece
| | - Frank Gieseler
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | | | - Michelle F Green
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - Brendan Grue
- Departments of Environmental Science, Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Gunjan Guha
- School of Chemical and Bio Technology, SASTRA University, Thanjavur, Tamil Nadu, India
| | - Dorota Halicka
- Department of Pathology, New York Medical College, Valhalla, NY, United States
| | | | - Petr Heneberg
- Charles University in Prague, Third Faculty of Medicine, Prague, Czech Republic
| | - Patricia Hentosh
- School of Medical Laboratory and Radiation Sciences, Old Dominion University, Norfolk, VA, United States
| | - Matthew D Hirschey
- Department of Medicine, Duke University Medical Center, Durham, NC, United States; Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - Lorne J Hofseth
- College of Pharmacy, University of South Carolina, Columbia, SC, United States
| | - Randall F Holcombe
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, United States
| | - Kanya Honoki
- Department of Orthopedic Surgery, Nara Medical University, Kashihara, Nara, Japan
| | - Hsue-Yin Hsu
- Department of Life Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Gloria S Huang
- Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States
| | - Lasse D Jensen
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Wen G Jiang
- Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Lee W Jones
- Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, United States
| | | | | | - Sid P Kerkar
- Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | | | - Mahin Khatami
- Inflammation and Cancer Research, National Cancer Institute (Retired), National Institutes of Health, Bethesda, MD, United States
| | - Young H Ko
- University of Maryland BioPark, Innovation Center, KoDiscovery, Baltimore, MD, United States
| | - Omer Kucuk
- Winship Cancer Institute of Emory University, Atlanta, GA, United States
| | - Rob J Kulathinal
- Department of Biology, Temple University, Philadelphia, PA, United States
| | - Nagi B Kumar
- Moffitt Cancer Center, University of South Florida College of Medicine, Tampa, FL, United States
| | - Byoung S Kwon
- Cancer Immunology Branch, Division of Cancer Biology, National Cancer Center, Goyang, Gyeonggi, Republic of Korea; Department of Medicine, Tulane University Health Sciences Center, New Orleans, LA, United States
| | - Anne Le
- The Sol Goldman Pancreatic Cancer Research Center, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Michael A Lea
- New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Ho-Young Lee
- College of Pharmacy, Seoul National University, South Korea
| | - Terry Lichtor
- Department of Neurosurgery, Rush University Medical Center, Chicago, IL, United States
| | - Liang-Tzung Lin
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jason W Locasale
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States
| | - Bal L Lokeshwar
- Department of Medicine, Georgia Regents University Cancer Center, Augusta, GA, United States
| | - Valter D Longo
- Andrus Gerontology Center, Division of Biogerontology, University of Southern California, Los Angeles, CA, United States
| | - Costas A Lyssiotis
- Department of Molecular and Integrative Physiology and Department of Internal Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, MI, United States
| | - Karen L MacKenzie
- Children's Cancer Institute Australia, Kensington, New South Wales, Australia
| | - Meenakshi Malhotra
- Department of Biomedical Engineering, McGill University, Montréal, Canada
| | - Maria Marino
- Department of Science, University Roma Tre, Rome, Italy
| | - Maria L Martinez-Chantar
- Metabolomic Unit, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Technology Park of Bizkaia, Bizkaia, Spain
| | | | - Christopher Maxwell
- Department of Pediatrics, University of British Columbia, Michael Cuccione Childhood Cancer Research Program, Child and Family Research Institute, Vancouver, British Columbia, Canada
| | - Eoin McDonnell
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - Alan K Meeker
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Mahya Mehrmohamadi
- Field of Genetics, Genomics, and Development, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, United States
| | - Kapil Mehta
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Gregory A Michelotti
- Department of Medicine, Duke University Medical Center, Durham, NC, United States
| | - Ramzi M Mohammad
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States
| | - Sulma I Mohammed
- Department of Comparative Pathobiology, Purdue University Center for Cancer Research, West Lafayette, IN, United States
| | - D James Morre
- Mor-NuCo, Inc, Purdue Research Park, West Lafayette, IN, United States
| | - Vinayak Muralidhar
- Harvard-MIT Division of Health Sciences and Technology, Harvard Medical School, Boston, MA, United States; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Irfana Muqbil
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, Wellcome Trust-MRC Building, Hills Road, Cambridge, United Kingdom
| | | | - Rita Nahta
- Winship Cancer Institute of Emory University, Atlanta, GA, United States
| | | | - Somaira Nowsheen
- Medical Scientist Training Program, Mayo Graduate School, Mayo Medical School, Mayo Clinic, Rochester, MN, United States
| | - Carolina Panis
- Laboratory of Inflammatory Mediators, State University of West Paraná, UNIOESTE, Paraná, Brazil
| | - Francesco Pantano
- Medical Oncology Department, University Campus Bio-Medico, Rome, Italy
| | - Virginia R Parslow
- Discipline of Nutrition and Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Graham Pawelec
- Center for Medical Research, University of Tübingen, Tübingen, Germany
| | - Peter L Pedersen
- Departments of Biological Chemistry and Oncology, Member at Large, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Brad Poore
- The Sol Goldman Pancreatic Cancer Research Center, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Deepak Poudyal
- College of Pharmacy, University of South Carolina, Columbia, SC, United States
| | - Satya Prakash
- Department of Biomedical Engineering, McGill University, Montréal, Canada
| | - Mark Prince
- Department of Otolaryngology-Head and Neck, Medical School, University of Michigan, Ann Arbor, MI, United States
| | | | - Jeffrey C Rathmell
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - W Kimryn Rathmell
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States
| | - Swapan K Ray
- Department of Pathology, Microbiology, and Immunology, University of South Carolina, School of Medicine, Columbia, SC, United States
| | - Jörg Reichrath
- Center for Clinical and Experimental Photodermatology, Clinic for Dermatology, Venerology and Allergology, The Saarland University Hospital, Homburg, Germany
| | - Sarallah Rezazadeh
- Department of Biology, University of Rochester, Rochester, NY, United States
| | - Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, Bari, Italy & National Cancer Institute Giovanni Paolo II, Bari, Italy
| | - Luigi Ricciardiello
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - R Brooks Robey
- White River Junction Veterans Affairs Medical Center, White River Junction, VT, United States; Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Francis Rodier
- Centre de Rechercher du Centre Hospitalier de l'Université de Montréal and Institut du Cancer de Montréal, Montréal, Quebec, Canada; Université de Montréal, Département de Radiologie, Radio-Oncologie et Médicine Nucléaire, Montréal, Quebec, Canada
| | - H P Vasantha Rupasinghe
- Department of Environmental Sciences, Faculty of Agriculture and Department of Pathology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Gian Luigi Russo
- Institute of Food Sciences National Research Council, Avellino, Italy
| | - Elizabeth P Ryan
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, United States
| | | | - Isidro Sanchez-Garcia
- Experimental Therapeutics and Translational Oncology Program, Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, Salamanca, Spain
| | - Andrew J Sanders
- Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Daniele Santini
- Medical Oncology Department, University Campus Bio-Medico, Rome, Italy
| | - Malancha Sarkar
- Department of Biology, University of Miami, Miami, FL, United States
| | - Tetsuro Sasada
- Department of Immunology, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Neeraj K Saxena
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Rodney E Shackelford
- Department of Pathology, Louisiana State University, Health Shreveport, Shreveport, LA, United States
| | - H M C Shantha Kumara
- Department of Surgery, St. Luke's Roosevelt Hospital, New York, NY, United States
| | - Dipali Sharma
- Department of Oncology, Johns Hopkins University School of Medicine and the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, United States
| | - Dong M Shin
- Winship Cancer Institute of Emory University, Atlanta, GA, United States
| | - David Sidransky
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Markus David Siegelin
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, United States
| | - Emanuela Signori
- National Research Council, Institute of Translational Pharmacology, Rome, Italy
| | - Neetu Singh
- Advanced Molecular Science Research Centre (Centre for Advanced Research), King George's Medical University, Lucknow, Uttar Pradesh, India
| | - Sharanya Sivanand
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Daniel Sliva
- DSTest Laboratories, Purdue Research Park, Indianapolis, IN, United States
| | - Carl Smythe
- Department of Biomedical Science, Sheffield Cancer Research Centre, University of Sheffield, Sheffield, United Kingdom
| | - Carmela Spagnuolo
- Institute of Food Sciences National Research Council, Avellino, Italy
| | - Diana M Stafforini
- Huntsman Cancer Institute and Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States
| | - John Stagg
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Faculté de Pharmacie et Institut du Cancer de Montréal, Montréal, Quebec, Canada
| | - Pochi R Subbarayan
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Tabetha Sundin
- Department of Molecular Diagnostics, Sentara Healthcare, Norfolk, VA, United States
| | - Wamidh H Talib
- Department of Clinical Pharmacy and Therapeutics, Applied Science University, Amman, Jordan
| | - Sarah K Thompson
- Department of Surgery, Royal Adelaide Hospital, Adelaide, Australia
| | - Phuoc T Tran
- Departments of Radiation Oncology & Molecular Radiation Sciences, Oncology and Urology, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Hendrik Ungefroren
- First Department of Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Vasundara Venkateswaran
- Department of Surgery, University of Toronto, Division of Urology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Dass S Vinay
- Section of Clinical Immunology, Allergy, and Rheumatology, Department of Medicine, Tulane University Health Sciences Center, New Orleans, LA, United States
| | - Panagiotis J Vlachostergios
- Department of Internal Medicine, New York University Lutheran Medical Center, Brooklyn, New York, NY, United States
| | - Zongwei Wang
- Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Kathryn E Wellen
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Richard L Whelan
- Department of Surgery, St. Luke's Roosevelt Hospital, New York, NY, United States
| | - Eddy S Yang
- Department of Radiation Oncology, University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States
| | - Huanjie Yang
- The School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Xujuan Yang
- University of Illinois at Urbana Champaign, Champaign, IL, United States
| | - Paul Yaswen
- Life Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA, United States
| | - Clement Yedjou
- Department of Biology, Jackson State University, Jackson, MS, United States
| | - Xin Yin
- Medicine and Research Services, Veterans Affairs San Diego Healthcare System & University of California, San Diego, CA, United States
| | - Jiyue Zhu
- Washington State University College of Pharmacy, Spokane, WA, United States
| | - Massimo Zollo
- Centro di Ingegneria Genetica e Biotecnologia Avanzate, Naples, Italy; Department of Molecular Medicine and Medical Biotechnology, Federico II, Via Pansini 5, 80131 Naples, Italy
| |
Collapse
|
4
|
Kundu A, Quirit JG, Khouri MG, Firestone GL. Inhibition of oncogenic BRAF activity by indole-3-carbinol disrupts microphthalmia-associated transcription factor expression and arrests melanoma cell proliferation. Mol Carcinog 2016; 56:49-61. [PMID: 26878440 DOI: 10.1002/mc.22472] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 01/28/2016] [Indexed: 12/18/2022]
Abstract
Indole-3-carbinol (I3C), an anti-cancer phytochemical derived from cruciferous vegetables, strongly inhibited proliferation and down-regulated protein levels of the melanocyte master regulator micropthalmia-associated transcription factor (MITF-M) in oncogenic BRAF-V600E expressing melanoma cells in culture as well as in vivo in tumor xenografted athymic nude mice. In contrast, wild type BRAF-expressing melanoma cells remained relatively insensitive to I3C anti-proliferative signaling. In BRAF-V600E-expressing melanoma cells, I3C treatment inhibited phosphorylation of MEK and ERK/MAPK, the down stream effectors of BRAF. The I3C anti-proliferative arrest was concomitant with the down-regulation of MITF-M transcripts and promoter activity, loss of endogenous BRN-2 binding to the MITF-M promoter, and was strongly attenuated by expression of exogenous MITF-M. Importantly, in vitro kinase assays using immunoprecipitated BRAF-V600E and wild type BRAF demonstrated that I3C selectively inhibited the enzymatic activity of the oncogenic BRAF-V600E but not of the wild type protein. In silico modeling predicted an I3C interaction site in the BRAF-V600E protomer distinct from where the clinically used BRAF-V600E inhibitor Vemurafenib binds to BRAF-V600E. Consistent with this prediction, combinations of I3C and Vemurafenib more potently inhibited melanoma cell proliferation and reduced MITF-M levels in BRAF-V600E expressing melanoma cells compared to the effects of each compound alone. Thus, our results demonstrate that oncogenic BRAF-V600E is a new cellular target of I3C that implicate this indolecarbinol compound as a potential candidate for novel single or combination therapies for melanoma. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Aishwarya Kundu
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California
| | - Jeanne G Quirit
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California
| | - Michelle G Khouri
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California
| | - Gary L Firestone
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California
| |
Collapse
|
5
|
Yaswen P, MacKenzie KL, Keith WN, Hentosh P, Rodier F, Zhu J, Firestone GL, Matheu A, Carnero A, Bilsland A, Sundin T, Honoki K, Fujii H, Georgakilas AG, Amedei A, Amin A, Helferich B, Boosani CS, Guha G, Ciriolo MR, Chen S, Mohammed SI, Azmi AS, Bhakta D, Halicka D, Niccolai E, Aquilano K, Ashraf SS, Nowsheen S, Yang X. Therapeutic targeting of replicative immortality. Semin Cancer Biol 2015; 35 Suppl:S104-S128. [PMID: 25869441 PMCID: PMC4600408 DOI: 10.1016/j.semcancer.2015.03.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 03/06/2015] [Accepted: 03/13/2015] [Indexed: 12/15/2022]
Abstract
One of the hallmarks of malignant cell populations is the ability to undergo continuous proliferation. This property allows clonal lineages to acquire sequential aberrations that can fuel increasingly autonomous growth, invasiveness, and therapeutic resistance. Innate cellular mechanisms have evolved to regulate replicative potential as a hedge against malignant progression. When activated in the absence of normal terminal differentiation cues, these mechanisms can result in a state of persistent cytostasis. This state, termed “senescence,” can be triggered by intrinsic cellular processes such as telomere dysfunction and oncogene expression, and by exogenous factors such as DNA damaging agents or oxidative environments. Despite differences in upstream signaling, senescence often involves convergent interdependent activation of tumor suppressors p53 and p16/pRB, but can be induced, albeit with reduced sensitivity, when these suppressors are compromised. Doses of conventional genotoxic drugs required to achieve cancer cell senescence are often much lower than doses required to achieve outright cell death. Additional therapies, such as those targeting cyclin dependent kinases or components of the PI3K signaling pathway, may induce senescence specifically in cancer cells by circumventing defects in tumor suppressor pathways or exploiting cancer cells’ heightened requirements for telomerase. Such treatments sufficient to induce cancer cell senescence could provide increased patient survival with fewer and less severe side effects than conventional cytotoxic regimens. This positive aspect is countered by important caveats regarding senescence reversibility, genomic instability, and paracrine effects that may increase heterogeneity and adaptive resistance of surviving cancer cells. Nevertheless, agents that effectively disrupt replicative immortality will likely be valuable components of new combinatorial approaches to cancer therapy.
Collapse
Affiliation(s)
- Paul Yaswen
- Life Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA, United States.
| | - Karen L MacKenzie
- Children's Cancer Institute Australia, Kensington, New South Wales, Australia.
| | | | | | | | - Jiyue Zhu
- Washington State University College of Pharmacy, Pullman, WA, United States.
| | | | | | - Amancio Carnero
- Instituto de Biomedicina de Sevilla, HUVR, Consejo Superior de Investigaciones Cientificas, Universdad de Sevilla, Seville, Spain.
| | | | | | | | | | | | | | - Amr Amin
- United Arab Emirates University, Al Ain, United Arab Emirates; Cairo University, Cairo, Egypt
| | - Bill Helferich
- University of Illinois at Urbana Champaign, Champaign, IL, United States
| | | | - Gunjan Guha
- SASTRA University, Thanjavur, Tamil Nadu, India
| | | | - Sophie Chen
- Ovarian and Prostate Cancer Research Trust, Guildford, Surrey, United Kingdom
| | | | - Asfar S Azmi
- Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States
| | | | | | | | | | - S Salman Ashraf
- United Arab Emirates University, Al Ain, United Arab Emirates; Cairo University, Cairo, Egypt
| | | | - Xujuan Yang
- University of Illinois at Urbana Champaign, Champaign, IL, United States
| |
Collapse
|
6
|
Hargraves KG, He L, Firestone GL. Phytochemical regulation of the tumor suppressive microRNA, miR-34a, by p53-dependent and independent responses in human breast cancer cells. Mol Carcinog 2015; 55:486-98. [PMID: 25789847 DOI: 10.1002/mc.22296] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [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: 08/19/2014] [Revised: 01/07/2015] [Accepted: 01/14/2015] [Indexed: 01/09/2023]
Abstract
The tumor suppressive microRNA miR-34a is transcriptionally regulated by p53 and shown to inhibit breast cancer cell proliferation as well as being a marker of increased disease free survival. Indole-3-carbinol (I3C) derived from cruciferous vegetables, artemisinin, extracted from the sweet wormwood plant, and artesunate, a semi-synthetic derivative of artemisinin, are phytochemicals with anti-tumorigenic properties however, little is known about the role of microRNAs in their mechanism of action. Human breast cancer cells expressing wild-type (MCF-7) or mutant p53 (T47D) were treated with a concentration range and time course of each phytochemical under conditions of cell cycle arrest as detected by flow cytometry to examine the potential connection between miR-34a expression and their anti-proliferative responses. Real-time PCR and western blot analysis of extracted RNA and total protein revealed artemsinin and artesunate increased miR-34a expression in a dose-dependent manner correlating with down-regulation of the miR-34a target gene, CDK4. I3C stimulation of miR-34a expression required functional p53, whereas, both artemisinin and artesunate up-regulated miR-34a expression regardless of p53 mutational status or in the presence of dominant negative p53. Phytochemical treatments inhibited the luciferase activity of a construct containing the wild-type 3'UTR of CDK4, but not those with a mutated miR-34a binding site, whereas, transfection of miR-34a inhibitors ablated the phytochemical mediated down-regulation of CDK4 and induction of cell cycle arrest. Our results suggest that miR-34a is an essential component of the anti-proliferative activities of I3C, artemisinin, and artesunate and demonstrate that both wild-type p53 dependent and independent pathways are responsible for miR-34a induction.
Collapse
Affiliation(s)
- Kris G Hargraves
- Department of Molecular and Cell Biology, The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California
| | - Lin He
- Department of Molecular and Cell Biology, The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California
| | - Gary L Firestone
- Department of Molecular and Cell Biology, The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California
| |
Collapse
|
7
|
Tin AS, Park AH, Sundar SN, Firestone GL. Essential role of the cancer stem/progenitor cell marker nucleostemin for indole-3-carbinol anti-proliferative responsiveness in human breast cancer cells. BMC Biol 2014; 12:72. [PMID: 25209720 PMCID: PMC4180847 DOI: 10.1186/s12915-014-0072-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Nucleostemin is a nucleolus residing GTPase that is considered to be an important cancer stem/progenitor cell marker protein due to its high expression levels in breast cancer stem cells and its role in tumor-initiation of human mammary tumor cells. It has been proposed that nucleostemin may represent a valuable therapeutic target for breast cancer; however, to date evidence supporting the cellular mechanism has not been elucidated. RESULTS Expression of exogenous HER2, a member of the EGF receptor gene family, in the human MCF-10AT preneoplastic mammary epithelial cell line formed a new breast cancer cell line, 10AT-Her2, which is highly enriched in cells with stem/progenitor cell-like character. 10AT-Her2 cells display a CD44+/CD24-/low phenotype with high levels of the cancer stem/progenitor cell marker proteins nucleostemin, and active aldehyde dehydrogenase-1. The overall expression pattern of HER2 protein and the stem/progenitor cell marker proteins in the 10AT-Her2 cell population is similar to that of the luminal HER2+ SKBR3 human breast cancer cell line, whereas, both MCF-7 and MDA-MB-231 cells display reduced levels of nucleostemin and no detectable expression of ALDH-1. Importantly, in contrast to the other well-established human breast cancer cell lines, 10AT-Her2 cells efficiently form tumorspheres in suspension cultures and initiate tumor xenograft formation in athymic mice at low cell numbers. Furthermore, 10AT-Her2 cells are highly sensitive to the anti-proliferative apoptotic effects of indole-3-carbinol (I3C), a natural anti-cancer indolecarbinol from cruciferous vegetables of the Brassica genus such as broccoli and cabbage. I3C promotes the interaction of nucleostemin with MDM2 (Murine Double Mutant 2), an inhibitor of the p53 tumor suppressor, and disrupts the MDM2 interaction with p53. I3C also induced nucleostemin to sequester MDM2 in a nucleolus compartment, thereby freeing p53 to mediate its apoptotic activity. siRNA knockdown of nucleostemin functionally documented that nucleostemin is required for I3C to trigger its cellular anti-proliferative responses, inhibit tumorsphere formation, and disrupt MDM2-p53 protein-protein interactions. Furthermore, expression of an I3C-resistant form of elastase, the only known target protein for I3C, prevented I3C anti-proliferative responses in cells and in tumor xenografts in vivo, as well as disrupt the I3C stimulated nucleostemin-MDM2 interactions. CONCLUSIONS Our results provide the first evidence that a natural anti-cancer compound mediates its cellular and in vivo tumor anti-proliferative responses by selectively stimulating cellular interactions of the stem/progenitor cell marker nucleostemin with MDM2, which frees p53 to trigger its apoptotic response. Furthermore, our study provides a new mechanistic template that can be potentially exploited for the development of cancer stem/progenitor cell targeted therapeutic strategies.
Collapse
|
8
|
Abstract
A diverse set of physiological signals control intercellular interactions by regulating the structure and function of occluding junctions (tight junctions) and anchoring junctions (adherens junctions and desmosomes). These plasma membrane junctions are comprised of multiprotein complexes of transmembrane and cytoplasmic peripheral plasma membrane proteins. Evidence from many hormone-responsive tissues has shown that expression, modification, molecular interactions, stability, and localization of junctional complex-associated proteins can be targeted by nuclear hormone receptors and their ligands through transcriptional and nontranscriptional mechanisms. The focus of this minireview is to discuss molecular, cellular, and physiological studies that directly link nuclear receptor- and ligand-triggered signaling pathways to the regulation of occluding and anchoring junction dynamics.
Collapse
Affiliation(s)
- Gary L Firestone
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California 94720-3200
| | | |
Collapse
|
9
|
Aronchik I, Kundu A, Quirit JG, Firestone GL. The antiproliferative response of indole-3-carbinol in human melanoma cells is triggered by an interaction with NEDD4-1 and disruption of wild-type PTEN degradation. Mol Cancer Res 2014; 12:1621-1634. [PMID: 25009292 DOI: 10.1158/1541-7786.mcr-14-0018] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
UNLABELLED Human melanoma cells displaying distinct PTEN genotypes were used to assess the cellular role of this important tumor-suppressor protein in the antiproliferative response induced by the chemopreventative agent indole-3-carbinol (I3C), a natural indolecarbinol compound derived from the breakdown of glucobrassicin produced in cruciferous vegetables such as broccoli and Brussels sprouts. I3C induced a G1-phase cell-cycle arrest and apoptosis by stabilization of PTEN in human melanoma cells that express wild-type PTEN, but not in cells with mutant or null PTEN genotypes. Importantly, normal human epidermal melanocytes were unaffected by I3C treatment. In wild-type PTEN-expressing melanoma xenografts, formed in athymic mice, I3C inhibited the in vivo tumor growth rate and increased PTEN protein levels in the residual tumors. Mechanistically, I3C disrupted the ubiquitination of PTEN by NEDD4-1 (NEDD4), which prevented the proteasome-mediated degradation of PTEN without altering its transcript levels. RNAi-mediated knockdown of PTEN prevented the I3C-induced apoptotic response, whereas knockdown of NEDD4-1 mimicked the I3C apoptotic response, stabilized PTEN protein levels, and downregulated phosphorylated AKT-1 levels. Co-knockdown of PTEN and NEDD4-1 revealed that I3C-regulated apoptotic signaling through NEDD4-1 requires the presence of the wild-type PTEN protein. Finally, in silico structural modeling, in combination with isothermal titration calorimetry analysis, demonstrated that I3C directly interacts with purified NEDD4-1 protein. IMPLICATIONS This study identifies NEDD4-1 as a new I3C target protein, and that the I3C disruption of NEDD4-1 ubiquitination activity triggers the stabilization of the wild-type PTEN tumor suppressor to induce an antiproliferative response in melanoma. Mol Cancer Res; 12(11); 1621-34. ©2014 AACR.
Collapse
Affiliation(s)
- Ida Aronchik
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, Univ. of California at Berkeley, Berkeley, CA 94720-3200
| | - Aishwarya Kundu
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, Univ. of California at Berkeley, Berkeley, CA 94720-3200
| | - Jeanne G Quirit
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, Univ. of California at Berkeley, Berkeley, CA 94720-3200
| | - Gary L Firestone
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, Univ. of California at Berkeley, Berkeley, CA 94720-3200
| |
Collapse
|
10
|
Nicastro HL, Firestone GL, Bjeldanes LF. 3,3'-diindolylmethane rapidly and selectively inhibits hepatocyte growth factor/c-Met signaling in breast cancer cells. J Nutr Biochem 2013; 24:1882-8. [PMID: 23968581 DOI: 10.1016/j.jnutbio.2013.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [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: 09/17/2012] [Revised: 01/31/2013] [Accepted: 05/04/2013] [Indexed: 10/26/2022]
Abstract
3,3'-Diindolylmethane (DIM), an indole derivative from vegetables of the Brassica genus, has antiproliferative activity in breast cancer cells. Part of this activity is thought to be due to DIM inhibition of Akt signaling, but an upstream mechanism of DIM-induced Akt inhibition has not been described. The goals of this study were to investigate the kinetics of inhibition of Akt by physiologically relevant concentrations of DIM and to identify an upstream factor that mediates this effect. Here we report that DIM (5-25 μM) inhibited Akt activation from 30 min to 24h in tumorigenic MDA-MB-231 cells but did not inhibit Akt activation in non-tumorigenic preneoplastic MCF10AT cells. DIM inhibited hepatocyte growth factor (HGF)-induced Akt activation by up to 46%, cell migration by 66% and cell proliferation by up to 54%, but did not inhibit induction of Akt by epidermal growth factor or insulin-like growth factor-1. DIM decreased phosphorylation of the HGF receptor, c-Met, at tyrosines 1234 and 1235, indicating decreased activation of the receptor. This decrease was reversed by pretreatment with inhibitors of p38 or calcineurin. Our results demonstrate the important role of HGF and c-Met in DIM's anti-proliferative effect on breast cancer cells and suggest that DIM could have preventive or clinical value as an inhibitor of c-Met signaling.
Collapse
Affiliation(s)
- Holly L Nicastro
- Department of Nutritional Science & Toxicology, University of California Berkeley, Berkeley, CA 94720-3104.
| | | | | |
Collapse
|
11
|
O'Keeffe BA, Cilia S, Maiyar AC, Vaysberg M, Firestone GL. The serum- and glucocorticoid-induced protein kinase-1 (Sgk-1) mitochondria connection: identification of the IF-1 inhibitor of the F(1)F(0)-ATPase as a mitochondria-specific binding target and the stress-induced mitochondrial localization of endogenous Sgk-1. Biochimie 2013; 95:1258-65. [PMID: 23402912 PMCID: PMC3684451 DOI: 10.1016/j.biochi.2013.01.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 01/30/2013] [Indexed: 12/28/2022]
Abstract
The expression, localization and activity of the serum- and glucocorticoid-induced protein kinase, Sgk-1, are regulated by multiple hormonal and environmental cues including cellular stress. Biochemical fractionation and indirect immunofluorescence demonstrated that sorbitol induced hyperosmotic stress stimulated expression and triggered the localization of endogenous Sgk-1 into the mitochondria of NMuMG mammary epithelial cells. The immunofluorescence pattern of endogenous Sgk-1 was similar to that of a green fluorescent linked fusion protein linked to the N-terminal Sgk-1 fragment that encodes the mitochondrial targeting signal. In the presence or absence of cellular stress, exogenously expressed wild type Sgk-1 efficiently compartmentalized into the mitochondria demonstrating the mitochondrial import machinery per se is not stressed regulated. Co-immunoprecipitation and GST-pull down assays identified the IF-1 mitochondrial matrix inhibitor of the F1F0-ATPase as a new Sgk-1 binding partner, which represents the first observed mitochondrial target of Sgk-1. The Sgk-1/IF-1 interaction requires the 122-176 amino acid region within the catalytic domain of Sgk-1 and is pH dependent, occurring at neutral pH but not at slightly acidic pH, which suggests that this interaction is dependent on mitochondrial integrity. An in vitro protein kinase assay showed that the F1F0-ATPase can be directly phosphorylated by Sgk-1. Taken together, our results suggest that stress-induced Sgk-1 localizes to the mitochondria, which permits access to physiologically appropriate mitochondrial interacting proteins and substrates, such as IF-1 and the F1F0-ATPase, as part of the cellular stressed induced program.
Collapse
Affiliation(s)
- Bridget A O'Keeffe
- Department of Molecular and Cell Biology and the Cancer Research Laboratory, 591 LSA, University of California at Berkeley, Berkeley, CA 94720-3200, USA
| | | | | | | | | |
Collapse
|
12
|
Marconett CN, Singhal AK, Sundar SN, Firestone GL. Indole-3-carbinol disrupts estrogen receptor-alpha dependent expression of insulin-like growth factor-1 receptor and insulin receptor substrate-1 and proliferation of human breast cancer cells. Mol Cell Endocrinol 2012; 363:74-84. [PMID: 22835548 PMCID: PMC3684449 DOI: 10.1016/j.mce.2012.07.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 07/16/2012] [Indexed: 11/15/2022]
Abstract
We previously established that Indole-3-Carbinol (I3C), a natural hydrolysis product of glucobrassicin in cruciferous vegetables, arrests the proliferation of estrogen-dependent human breast cancer cells and induces protein degradation of Estrogen Receptor-alpha (ERα). We demonstrate in human MCF-7 breast cancer cells that I3C ablates expression of Insulin-like Growth Factor Receptor-1 (IGF1R) and Insulin Receptor Substrate-1 (IRS1), downstream effectors of the IGF1 signaling pathway. Exogenous ERα reversed the I3C mediated loss of IGF1R and IRS1 gene expression demonstrating that down-regulation of ERα is functionally linked to I3C control of IGF1R and IRS1 expression. I3C disrupted binding of endogenous ERα, but not Sp1, to ERE-Sp1 composite elements within the IGF1R/IRS1 promoters. Exogenous ERα abrogated, and combined expression of IGF1R and IRS1 attenuated, the I3C mediated cell cycle arrest. Therefore, I3C inhibits proliferation of estrogen-sensitive breast cancer cells through disruption of ERα-mediated transcription of cell signaling components within the IGF1 cascade.
Collapse
Affiliation(s)
| | | | | | - Gary L. Firestone
- To whom correspondence should be addressed. University of California, Berkeley Department of Molecular & Cell Biology, 142 Life Sciences Addition # 3200, Berkeley, CA 94720-3200; Tel (510) 642-8319; Fax (510) 643-6791;
| |
Collapse
|
13
|
Abstract
Gap junctions are plasma membrane channels comprising connexin proteins that mediate intercellular permeability and communication. The presence, composition, and function of gap junctions can be regulated by diverse sets of physiological signals. Evidence from many hormone-responsive tissues has shown that connexin expression, modification, stability, and localization can be targeted by nuclear hormone receptors and their ligands through both transcriptional and nontranscriptional mechanisms. The focus of this review is to discuss molecular, cellular, and physiological studies that directly link receptor- and ligand-triggered signaling pathways to the regulation of gap junction dynamics.
Collapse
Affiliation(s)
- Gary L Firestone
- Department of Molecular and Cell Biology, 591 LSA, The University of California at Berkeley, Berkeley, California 94720-3200, USA.
| | | |
Collapse
|
14
|
Aronchik I, Chen T, Durkin KA, Horwitz MS, Preobrazhenskaya MN, Bjeldanes LF, Firestone GL. Target protein interactions of indole-3-carbinol and the highly potent derivative 1-benzyl-I3C with the C-terminal domain of human elastase uncouples cell cycle arrest from apoptotic signaling. Mol Carcinog 2011; 51:881-94. [PMID: 22012859 DOI: 10.1002/mc.20857] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 07/28/2011] [Accepted: 08/19/2011] [Indexed: 12/15/2022]
Abstract
Elastase is the only currently identified target protein for indole-3-carbinol (I3C), a naturally occurring hydrolysis product of glucobrassicin in cruciferous vegetables such as broccoli, cabbage, and Brussels sprouts that induces a cell cycle arrest and apoptosis of human breast cancer cells. In vitro elastase enzymatic assays demonstrated that I3C and at lower concentrations its more potent derivative 1-benzyl-indole-3-carbinol (1-benzyl-I3C) act as non-competitive allosteric inhibitors of elastase activity. Consistent with these results, in silico computational simulations have revealed the first predicted interactions of I3C and 1-benzyl-I3C with the crystal structure of human neutrophil elastase, and identified a potential binding cluster on an external surface of the protease outside of the catalytic site that implicates elastase as a target protein for both indolecarbinol compounds. The Δ205 carboxyterminal truncation of elastase, which disrupts the predicted indolecarbinol binding site, is enzymatically active and generates a novel I3C resistant enzyme. Expression of the wild type and Δ205 elastase in MDA-MB-231 human breast cancer cells demonstrated that the carboxyterminal domain of elastase is required for the I3C and 1-benzyl-I3C inhibition of enzymatic activity, accumulation of the unprocessed form of the CD40 elastase substrate (a tumor necrosis factor receptor family member), disruption of NFκB nuclear localization and transcriptional activity, and induction of a G1 cell cycle arrest. Surprisingly, expression of the Δ205 elastase molecule failed to reverse indolecarbinol stimulated apoptosis, establishing an elastase-dependent bifurcation point in anti-proliferative signaling that uncouples the cell cycle and apoptotic responses in human breast cancer cells.
Collapse
Affiliation(s)
- Ida Aronchik
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, California 94720-3200, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
Marconett CN, Sundar SN, Tseng M, Tin AS, Tran KQ, Mahuron KM, Bjeldanes LF, Firestone GL. Indole-3-carbinol downregulation of telomerase gene expression requires the inhibition of estrogen receptor-alpha and Sp1 transcription factor interactions within the hTERT promoter and mediates the G1 cell cycle arrest of human breast cancer cells. Carcinogenesis 2011; 32:1315-23. [PMID: 21693539 DOI: 10.1093/carcin/bgr116] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Indole-3-carbinol (I3C), a naturally occurring hydrolysis product of glucobrassicin from cruciferous vegetables such as broccoli, cabbage and Brussels sprouts, is an anticancer phytochemical that triggers complementary sets of antiproliferative pathways to induce a cell cycle arrest of estrogen-responsive MCF7 breast cancer cells. I3C strongly downregulated transcript expression of the catalytic subunit of the human telomerase (hTERT) gene, which correlated with the dose-dependent indole-mediated G(1) cell cycle arrest without altering the transcript levels of the RNA template (hTR) for telomerase elongation. Exogenous expression of hTERT driven by a constitutive promoter prevented the I3C-induced cell cycle arrest and rescued the I3C inhibition of telomerase enzymatic activity and activation of cellular senescence. Time course studies showed that I3C downregulated expression of estrogen receptor-alpha (ERα) and cyclin-dependent kinase-6 transcripts levels (which is regulated through the Sp1 transcription factor) prior to the downregulation of hTERT suggesting a mechanistic link. Chromatin immunoprecipitation assays demonstrated that I3C disrupted endogenous interactions of both ERα and Sp1 with an estrogen response element-Sp1 composite element within the hTERT promoter. I3C inhibited 17β-estradiol stimulated hTERT expression and stimulated the production of threonine-phosphorylated Sp1, which inhibits Sp1-DNA interactions. Exogenous expression of both ERα and Sp1, but not either alone, in MCF7 cells blocked the I3C-mediated downregulation of hTERT expression. These results demonstrate that I3C disrupts the combined ERα- and Sp1-driven transcription of hTERT gene expression, which plays a significant role in the I3C-induced cell cycle arrest of human breast cancer cells.
Collapse
Affiliation(s)
- Crystal N Marconett
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California, Berkeley, CA 94720-3200, USA
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Firestone GL. Unraveling the intricacies of receptor activated cell signaling and transcriptional cascades enhance opportunities to develop new therapeutic targets for endocrine and metabolic diseases. Curr Opin Pharmacol 2010; 10:607-12. [PMID: 21036104 DOI: 10.1016/j.coph.2010.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
17
|
Marconett CN, Morgenstern TJ, San Roman AK, Sundar SN, Singhal AK, Firestone GL. BZL101, a phytochemical extract from the Scutellaria barbata plant, disrupts proliferation of human breast and prostate cancer cells through distinct mechanisms dependent on the cancer cell phenotype. Cancer Biol Ther 2010; 10:397-405. [PMID: 20574166 DOI: 10.4161/cbt.10.4.12424] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BZL101 is an aqueous extract from the Scutellaria barbata plant shown to have anticancer properties in a variety of human cancers. In order to determine its efficacy on human reproductive cancers, we assessed the responses of two human breast cancer cell lines, estrogen sensitive MCF7 and estrogen insensitive MDA-MB-231, and of two human prostate cancer cell lines, androgen sensitive LNCaP and androgen insensitive PC3 which are human cell lines that represent early and late stage reproductive cancers. BZL101 inhibited reproductive cancer growth in all cell lines by regulating expression levels of key cell cycle components that differ with respect to the cancer cell phenotypes. In early stage estrogen sensitive MCF7 cells, BZL101 induced a G₁ cell cycle arrest and ablated expression of key G₁ cell cycle regulators Cyclin D1, CDK2 and CDK4, as well as growth factor stimulatory pathways and estrogen receptor-α expression. Transfection of luciferase reporter plasmids revealed that the loss of CDK2, CDK4 and estrogen receptor-α transcript expression resulted from the BZL-dependent ablation of promoter activities. BZL101 growth arrests early stage androgen sensitive LNCaP cells in the G₂/M phase with corresponding decreases in Cyclin B1, CDK1 and androgen receptor expression. In late stage hormone insensitive breast (MDA-MB-231) and prostate (PC3) cancer cells, BZL101 induced an S phase arrest with corresponding ablations in Cyclin A2 and CDK2 expression. Our results demonstrate that BZL101 exerts phenotype specific anti-proliferative gene expression responses in human breast and prostate cancer cells, which will be valuable in the potential development of BZL-based therapeutic strategies for human reproductive cancers.
Collapse
Affiliation(s)
- Crystal N Marconett
- Department of Molecular and Cell Biology, University of California at Berkeley, USA
| | | | | | | | | | | |
Collapse
|
18
|
Giri S, Poindexter KM, Sundar SN, Firestone GL. Arecoline induced disruption of expression and localization of the tight junctional protein ZO-1 is dependent on the HER 2 expression in human endometrial Ishikawa cells. BMC Cell Biol 2010; 11:53. [PMID: 20604955 PMCID: PMC2910664 DOI: 10.1186/1471-2121-11-53] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 07/06/2010] [Indexed: 11/21/2022] Open
Abstract
Background Approximately 600 million people chew Betel nut, making this practice the fourth most popular oral habit in the world. Arecoline, the major alkaloid present in betel nut is one of the causative agents for precancerous lesions and several cancers of mouth among those who chew betel nut. Arecoline can be detected in the human embryonic tissue and is correlated to low birth weight of newborns whose mothers chew betel nut during pregnancy, suggesting that arecoline can induce many systemic effects. However, few reports exist as to the effects of arecoline in human tissues other than oral cancer cell lines. Furthermore, in any system, virtually nothing is known about the cellular effects of arecoline treatment on membrane associated signaling components of human cancer cells. Results Using the human Ishikawa endometrial cancer cell line, we investigated the effects of arecoline on expression, localization and functional connections between the ZO-1 tight junction protein and the HER2 EGF receptor family member. Treatment of Ishikawa cells with arecoline coordinately down-regulated expression of both ZO-1 and HER2 protein and transcripts in a dose dependent manner. Biochemical fractionation of cells as well as indirect immunofluorescence revealed that arecoline disrupted the localization of ZO-1 to the junctional complex at the cell periphery. Compared to control transfected cells, ectopic expression of exogenous HER2 prevented the arecoline mediated down-regulation of ZO-1 expression and restored the localization of ZO-1 to the cell periphery. Furthermore, treatment with dexamethasone, a synthetic glucocorticoid reported to up-regulate expression of HER2 in Ishikawa cells, precluded arecoline from down-regulating ZO-1 expression and disrupting ZO-1 localization. Conclusion Arecoline is known to induce precancerous lesions and cancer in the oral cavity of betel nut users. The arecoline down-regulation of ZO-1 expression and subcellular distribution suggests that arecoline potentially disrupts cell-cell interactions mediated by ZO-1, which may play a role in arecoline-mediated carcinogenesis. Furthermore, our study has uncovered the dependency of ZO-1 localization and expression on HER2 expression, which has therefore established a new cellular link between HER2 mediated signaling and apical junction formation involving ZO-1.
Collapse
Affiliation(s)
- Sarbani Giri
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | | | | | | |
Collapse
|
19
|
Aronchik I, Bjeldanes LF, Firestone GL. Direct inhibition of elastase activity by indole-3-carbinol triggers a CD40-TRAF regulatory cascade that disrupts NF-kappaB transcriptional activity in human breast cancer cells. Cancer Res 2010; 70:4961-71. [PMID: 20530686 DOI: 10.1158/0008-5472.can-09-3349] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Treatment of highly tumorigenic MDA-MB-231 human breast cancer cells with indole-3-carbinol (I3C) directly inhibited the extracellular elastase-dependent cleavage of membrane-associated CD40, a member of the tumor necrosis factor (TNF) receptor superfamily. CD40 signaling has been implicated in regulating cell survival, apoptosis, and proliferation, as well as in sensitizing breast cancer cells to chemotherapy, and is therefore an important potential target of novel breast cancer treatments. The I3C-dependent accumulation of full-length unprocessed CD40 protein caused a shift in CD40 signaling through TNF receptor-associated factors (TRAF), including the TRAF1/TRAF2 positive regulators and TRAF3 negative regulator of NF-kappaB transcription factor activity. Because TRAF1 is a transcriptional target gene of NF-kappaB, I3C disrupted a positive feedback loop involving these critical cell survival components. siRNA ablation of elastase expression mimicked the I3C inhibition of CD40 protein processing and G(1) cell cycle arrest, whereas siRNA knockdown of TRAF3 and the NF-kappaB inhibitor IkappaB prevented the I3C-induced cell cycle arrest. In contrast, siRNA knockdown of PTEN had no effect on the I3C control of NF-kappaB activity, showing the importance of CD40 signaling in regulating this transcription factor. Our study provides the first direct in vitro evidence that I3C directly inhibits the elastase-mediated proteolytic processing of CD40, which alters downstream signaling to disrupt NF-kappaB-induced cell survival and proliferative responses. Furthermore, we have established a new I3C-mediated antiproliferative cascade that has significant therapeutic potential for treatment of human cancers associated with high levels of elastase and its CD40 membrane substrate.
Collapse
Affiliation(s)
- Ida Aronchik
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3200, USA
| | | | | |
Collapse
|
20
|
Nguyen HH, Lavrenov SN, Sundar SN, Nguyen DHH, Tseng M, Marconett CN, Kung J, Staub RE, Preobrazhenskaya MN, Bjeldanes LF, Firestone GL. 1-Benzyl-indole-3-carbinol is a novel indole-3-carbinol derivative with significantly enhanced potency of anti-proliferative and anti-estrogenic properties in human breast cancer cells. Chem Biol Interact 2010; 186:255-66. [PMID: 20570586 DOI: 10.1016/j.cbi.2010.05.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 05/26/2010] [Accepted: 05/26/2010] [Indexed: 11/29/2022]
Abstract
Indole-3-carbinol (I3C), a natural autolysis product of a gluccosinolate present in Brassica vegetables such as broccoli and cabbage, has anti-proliferative and anti-estrogenic activities in human breast cancer cells. A new and significantly more potent I3C analogue, 1-benzyl-I3C was synthesized, and in comparison to I3C, this novel derivative displayed an approximate 1000-fold enhanced potency in suppressing the growth of both estrogen responsive (MCF-7) and estrogen-independent (MDA-MB-231) human breast cancer cells (I3C IC(50) of 52 microM, and 1-benzyl-I3C IC(50) of 0.05 microM). At significantly lower concentrations, 1-benzyl-I3C induced a robust G1 cell cycle arrest and elicited the key I3C-specific effects on expression and activity of G1-acting cell cycle genes including the disruption of endogenous interactions of the Sp1 transcription factor with the CDK6 promoter. Furthermore, in estrogen responsive MCF-7 cells, with enhanced potency 1-benzyl-I3C down-regulated production of estrogen receptor-alpha protein, acts with tamoxifen to arrest breast cancer cell growth more effectively than either compound alone, and inhibited the in vivo growth of human breast cancer cell-derived tumor xenografts in athymic mice. Our results implicate 1-benzyl-I3C as a novel, potent inhibitor of human breast cancer proliferation and estrogen responsiveness that could potentially be developed into a promising therapeutic agent for the treatment of indole-sensitive cancers.
Collapse
Affiliation(s)
- Hanh H Nguyen
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, Univ. of California at Berkeley, Berkeley, CA 94720-3200, United States
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
3,3'-Diindolylmethane (DIM) is a natural compound found in cruciferous vegetables that has antiproliferative and estrogenic activity. However, it is not clear whether the estrogenic effects are mediated through estrogen receptor (ER)alpha, ERbeta, or both ER subtypes. We investigated whether DIM has ER subtype selectivity on gene transcription. DIM stimulated ERbeta but not ERalpha activation of an estrogen response element upstream of the luciferase reporter gene. DIM also selectively activated multiple endogenous genes through ERbeta. DIM did not bind to ERbeta, indicating that it activates genes by a ligand-independent mechanism. DIM causes ERbeta to bind regulatory elements and recruit the steroid receptor coactivator (SRC)-2 coactivator, which leads to the activation of ER target genes. Silencing of SRC-2 inhibited the activation of ER target genes, demonstrating that SRC-2 is required for transcriptional activation by DIM. Our results demonstrate that DIM is a new class of ERbeta-selective compounds, because it does not bind to ERbeta, but instead it selectively recruits ERbeta and coactivators to target genes.
Collapse
Affiliation(s)
- Omar I Vivar
- Department of Nutritional Science and Toxicology, University of California, Berkeley, Berkeley, California 94720-3104, USA
| | | | | | | | | |
Collapse
|
22
|
Marconett CN, Sundar SN, Poindexter KM, Stueve TR, Bjeldanes LF, Firestone GL. Indole-3-carbinol triggers aryl hydrocarbon receptor-dependent estrogen receptor (ER)alpha protein degradation in breast cancer cells disrupting an ERalpha-GATA3 transcriptional cross-regulatory loop. Mol Biol Cell 2010; 21:1166-77. [PMID: 20130088 PMCID: PMC2847521 DOI: 10.1091/mbc.e09-08-0689] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We have established in human breast cancer cells that indole-3-carbinol (I3C), a promising anti-cancer phytochemical from Brassica vegetables, ablates ERα expression by stimulating the Rbx-1 E3 ligase mediated degradation of ERα protein and disruption of a cross-regulatory positive feedback loop involving ERα and the GATA3 transcription factor. Estrogen receptor (ER)α is a critical target of therapeutic strategies to control the proliferation of hormone-dependent breast cancers. Preferred clinical options have significant adverse side effects that can lead to treatment resistance due to the persistence of active estrogen receptors. We have established the cellular mechanism by which indole-3-carbinol (I3C), a promising anticancer phytochemical from Brassica vegetables, ablates ERα expression, and we have uncovered a critical role for the GATA3 transcription factor in this indole-regulated cascade. I3C-dependent activation of the aryl hydrocarbon receptor (AhR) initiates Rbx-1 E3 ligase-mediated ubiquitination and proteasomal degradation of ERα protein. I3C inhibits endogenous binding of ERα with the 3′-enhancer region of GATA3 and disrupts endogenous GATA3 interactions with the ERα promoter, leading to a loss of GATA3 and ERα expression. Ectopic expression of GATA3 has no effect on I3C-induced ERα protein degradation but does prevent I3C inhibition of ERα promoter activity, demonstrating the importance of GATA3 in this I3C-triggered cascade. Our preclinical results implicate I3C as a novel anticancer agent in human cancers that coexpress ERα, GATA3, and AhR, a combination found in a large percentage of breast cancers but not in other critical ERα target tissues essential to patient health.
Collapse
Affiliation(s)
- Crystal N Marconett
- Department of Molecular and Cell Biology, University of California-Berkeley, CA 94720, USA
| | | | | | | | | | | |
Collapse
|
23
|
Abstract
Indole-3-carbinol and its diindole condensation product 3-3'-diindolylmethane are dietary phytochemicals that have striking anticarcinogenic properties in human cancer cells. Molecular, cellular, physiological, and clinical studies have documented that both indole-3-carbinol and 3-3'-diindolylmethane have potent endocrine modulating activities through a myriad of mechanisms. The focus of this review is to discuss the evidence that directly links the anticancer actions of these two indole compounds to the control of steroid receptor and growth factor receptor signaling.
Collapse
Affiliation(s)
- Gary L Firestone
- Department of Molecular and Cell Biology, The University of California at Berkeley, 94720-3200, USA.
| | | |
Collapse
|
24
|
Brew CT, Aronchik I, Kosco K, McCammon J, Bjeldanes LF, Firestone GL. Indole-3-carbinol inhibits MDA-MB-231 breast cancer cell motility and induces stress fibers and focal adhesion formation by activation of Rho kinase activity. Int J Cancer 2009; 124:2294-302. [PMID: 19173291 PMCID: PMC3400502 DOI: 10.1002/ijc.24210] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Indole-3-carbinol (I3C), a phytochemical derived from cruciferous vegetables such as broccoli and Brussels sprouts, has potent antiproliferative effects in human breast cancer cells and has been shown to decrease metastatic spread of tumors in experimental animals. Using chemotaxis and fluorescent-bead cell motility assays, we demonstrated that I3C significantly decreased the in vitro migration of MDA-MB-231 cells, a highly invasive breast cancer cell line. Immunofluorescence staining of the actin cytoskeleton revealed that concurrent with the loss of cell motility, I3C treatment significantly increased stress fiber formation. Furthermore, I3C induced the localization of the focal adhesion component vinculin and tyrosine-phosphorylated proteins to the cell periphery, which implicates an indole-dependent enhancement of focal adhesions within the outer boundary of the cells. Coimmunoprecipitation analysis of focal adhesion kinase demonstrated that I3C stimulated the dynamic formation of the focal adhesion protein complex without altering the total level of individual focal adhesion proteins. The RhoA-Rho kinase pathway is involved in stress fiber and focal adhesion formation, and I3C treatment stimulated Rho kinase enzymatic activity and cofilin phosphorylation, which is a downstream target of Rho kinase signaling, but did not increase the level of active GTP-bound RhoA. Exposure of MDA-MB-231 cells to the Rho kinase inhibitor Y-27632, or expression of dominant negative RhoA ablated the I3C induced formation of stress fibers and of peripheral focal adhesions. Expression of constitutively active RhoA mimicked the I3C effects on both processes. Taken together, our data demonstrate that I3C induces stress fibers and peripheral focal adhesions in a Rho kinase-dependent manner that leads to an inhibition of motility in human breast cancer cells.
Collapse
Affiliation(s)
- Christine T. Brew
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, The University of California at Berkeley, Berkeley, CA 94720
| | - Ida Aronchik
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, The University of California at Berkeley, Berkeley, CA 94720
| | - Karena Kosco
- Signal Transduction Program, The Burnham Institute, La Jolla, CA 92037
| | - Jasmine McCammon
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, The University of California at Berkeley, Berkeley, CA 94720
| | - Leonard F. Bjeldanes
- Department of Nutritional Sciences and Toxicology, The University of California at Berkeley, Berkeley, CA 94720
| | - Gary L. Firestone
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, The University of California at Berkeley, Berkeley, CA 94720
| |
Collapse
|
25
|
Ball LJ, Levy N, Zhao X, Griffin C, Tagliaferri M, Cohen I, Ricke WA, Speed TP, Firestone GL, Leitman DC. Cell type- and estrogen receptor-subtype specific regulation of selective estrogen receptor modulator regulatory elements. Mol Cell Endocrinol 2009; 299:204-11. [PMID: 19059307 PMCID: PMC3420066 DOI: 10.1016/j.mce.2008.10.050] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 10/08/2008] [Accepted: 10/24/2008] [Indexed: 11/28/2022]
Abstract
Selective estrogen receptor modulators (SERMs), such as tamoxifen and raloxifene can act as estrogen receptor (ER) antagonists or agonists depending on the cell type. The antagonistic action of tamoxifen has been invaluable for treating breast cancer, whereas the agonist activity of SERMs also has important clinical applications as demonstrated by the use of raloxifene for osteoporosis. Whereas the mechanism whereby SERMs function as antagonists has been studied extensively very little is known about how SERMs produce agonist effects in different tissues with the two ER types; ERalpha and ERbeta. We examined the regulation of 32 SERM-responsive regions with ERalpha and ERbeta in transiently transfected MCF-7 breast, Ishikawa endometrial, HeLa cervical and WAR-5 prostate cancer cells. The regions were regulated by tamoxifen and raloxifene in some cell types, but not in all cell lines. Tamoxifen activated similar number of regions with ERalpha and ERbeta in the cell lines, whereas raloxifene activated over twice as many regions with ERbeta compared to ERalpha. In Ishikawa endometrial cancer cells, tamoxifen activated 17 regions with ERalpha, whereas raloxifene activated only 2 regions, which might explain their different effects on the endometrium. Microarray studies also found that raloxifene regulated fewer genes than tamoxifen in U2OS bone cancer cells expressing ERalpha, whereas tamoxifen was equally effective at regulating genes with ERalpha and ERbeta. Our studies indicate that tamoxifen is a non-selective agonist, whereas raloxifene is a relative ERbeta-selective agonist, and suggest that ERbeta-selective SERMs might be safer for treating clinical conditions that are dependent on the agonist property of SERMs.
Collapse
Affiliation(s)
- Lonnele J. Ball
- Departments of Obstetrics, Gynecology and Reproductive Sciences, Cellular and Molecular Pharmacology, Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
| | - Nitzan Levy
- Departments of Obstetrics, Gynecology and Reproductive Sciences, Cellular and Molecular Pharmacology, Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
| | | | - Chandi Griffin
- Departments of Obstetrics, Gynecology and Reproductive Sciences, Cellular and Molecular Pharmacology, Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
| | | | | | - William A. Ricke
- Department of Urology, James P. Wilmot Cancer Center, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Terence P. Speed
- Department of Statistics, University of California, Berkeley, CA 94720, USA
- Division of Bioinformatics, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Gary L. Firestone
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Dale C. Leitman
- Departments of Obstetrics, Gynecology and Reproductive Sciences, Cellular and Molecular Pharmacology, Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
- Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, CA 94720, USA
- Corresponding author at: Departments of Obstetrics, Gynecology and Reproductive Sciences, Cellular and Molecular Pharmacology, University of California, San Francisco, S1258 P.O. Box 0556, San Francisco, CA 94143-0556, USA. Tel.: +1 415 502 5262. (D.C. Leitman)
| |
Collapse
|
26
|
Willoughby JA, Sundar SN, Cheung M, Tin AS, Modiano J, Firestone GL. Artemisinin blocks prostate cancer growth and cell cycle progression by disrupting Sp1 interactions with the cyclin-dependent kinase-4 (CDK4) promoter and inhibiting CDK4 gene expression. J Biol Chem 2008; 284:2203-13. [PMID: 19017637 DOI: 10.1074/jbc.m804491200] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Artemisinin, a naturally occurring component of Artemisia annua, or sweet wormwood, is a potent anti-malaria compound that has recently been shown to have anti-proliferative effects on a number of human cancer cell types, although little is know about the molecular mechanisms of this response. We have observed that artemisinin treatment triggers a stringent G1 cell cycle arrest of LNCaP (lymph node carcinoma of the prostate) human prostate cancer cells that is accompanied by a rapid down-regulation of CDK2 and CDK4 protein and transcript levels. Transient transfection with promoter-linked luciferase reporter plasmids revealed that artemisinin strongly inhibits CDK2 and CDK4 promoter activity. Deletion analysis of the CDK4 promoter revealed a 231-bp artemisinin-responsive region between -1737 and -1506. Site-specific mutations revealed that the Sp1 site at -1531 was necessary for artemisinin responsiveness in the context of the CDK4 promoter. DNA binding assays as well as chromatin immunoprecipitation assays demonstrated that this Sp1-binding site in the CDK4 promoter forms a specific artemisinin-responsive DNA-protein complex that contains the Sp1 transcription factor. Artemisinin reduced phosphorylation of Sp1, and when dephosphorylation of Sp1 was inhibited by treatment of cells with the phosphatase inhibitor okadaic acid, the ability of artemisinin to down-regulate Sp1 interactions with the CDK4 promoter was ablated, rendering the CDK4 promoter unresponsive to artemisinin. Finally, overexpression of Sp1 mostly reversed the artemisinin down-regulation of CDK4 promoter activity and partially reversed the cell cycle arrest. Taken together, our results demonstrate that a key event in the artemisinin anti-proliferative effects in prostate cancer cells is the transcriptional down-regulation of CDK4 expression by disruption of Sp1 interactions with the CDK4 promoter.
Collapse
Affiliation(s)
- Jamin A Willoughby
- Department of Molecular and Cell Biology and Cancer Research Laboratory, University of California at Berkeley, Berkeley, California 94720-3200, USA
| | | | | | | | | | | |
Collapse
|
27
|
Sundar SN, Marconett CN, Doan VB, Willoughby JA, Firestone GL. Artemisinin selectively decreases functional levels of estrogen receptor-alpha and ablates estrogen-induced proliferation in human breast cancer cells. Carcinogenesis 2008; 29:2252-8. [PMID: 18784357 DOI: 10.1093/carcin/bgn214] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
MCF7 cells are an estrogen-responsive human breast cancer cell line that expresses both estrogen receptor (ER) alpha and ERbeta. Treatment of MCF7 cells with artemisinin, an antimalarial phytochemical from the sweet wormwood plant, effectively blocked estrogen-stimulated cell cycle progression induced by either 17beta-estradiol (E(2)), an agonist for both ERs, or by propyl pyrazole triol (PPT), a selective ERalpha agonist. Artemisinin strongly downregulated ERalpha protein and transcripts without altering expression or activity of ERbeta. Transfection of MCF7 cells with ERalpha promoter-linked luciferase reporter plasmids revealed that the artemisinin downregulation of ERalpha promoter activity accounted for the loss of ERalpha expression. Artemisinin treatment ablated the estrogenic induction of endogenous progesterone receptor (PR) transcripts by either E(2) or PPT and inhibited the estrogenic stimulation of a luciferase reporter plasmid driven by consensus estrogen response elements (EREs). Chromatin immunoprecipitation assays revealed that artemisinin significantly downregulated the level of endogeneous ERalpha bound to the PR promoter, whereas the level of bound endogeneous ERbeta was not altered. Treatment of MCF7 cells with artemisinin and the pure antiestrogen fulvestrant resulted in a cooperative reduction of ERalpha protein levels and enhanced G(1) cell cycle arrest compared with the effects of either compound alone. Our results show that artemisinin switches proliferative human breast cancer cells from expressing a high ERalpha:ERbeta ratio to a condition in which ERbeta predominates, which parallels the physiological state linked to antiproliferative events in normal mammary epithelium.
Collapse
Affiliation(s)
- Shyam N Sundar
- Department of Molecular and Cell Biology and the Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA 94720, USA
| | | | | | | | | |
Collapse
|
28
|
Xue L, Pestka JJ, Li M, Firestone GL, Bjeldanes LF. 3,3'-Diindolylmethane stimulates murine immune function in vitro and in vivo. J Nutr Biochem 2008; 19:336-44. [PMID: 17707631 PMCID: PMC2387240 DOI: 10.1016/j.jnutbio.2007.05.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 04/23/2007] [Accepted: 05/03/2007] [Indexed: 12/25/2022]
Abstract
3,3'-Diindolylmethane (DIM), a major condensation product of indole-3-carbinol, exhibits chemopreventive properties in animal models of cancer. Recent studies have shown that DIM stimulates interferon-gamma (IFN-gamma) production and potentiates the IFN-gamma signaling pathway in human breast cancer cells via a mechanism that includes increased expression of the IFN-gamma receptor. The goal of this study was to test the hypothesis that DIM modulates the murine immune function. Specifically, the effects of DIM were evaluated in a panel of murine immune function tests that included splenocyte proliferation, reactive oxygen species (ROS) generation, cytokine production and resistance to viral infection. DIM was found to induce proliferation of splenocytes as well as augment mitogen- and interleukin (IL)-2-induced splenocyte proliferation. DIM also stimulated the production of ROS by murine peritoneal macrophage cultures. Oral administration of DIM, but not intraperitoneal injection, induced elevation of serum cytokines in mice, including IL-6, granulocyte colony-stimulating factor (G-CSF), IL-12 and IFN-gamma. Finally, in a model of enteric virus infection, oral DIM administration to mice enhanced both clearance of reovirus from the GI tract and the subsequent mucosal IgA response. Thus, DIM is a potent stimulator of immune function. This property might contribute to the cancer inhibitory effects of this indole.
Collapse
Affiliation(s)
- Ling Xue
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720-3104, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3104, USA
| | - James J. Pestka
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, 48824-1224, USA
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA
| | - Maoxiang Li
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, 48824-1224, USA
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA
| | - Gary L Firestone
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3104, USA
| | - Leonard F. Bjeldanes
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720-3104, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3104, USA
| |
Collapse
|
29
|
Cen H, Mao F, Aronchik I, Fuentes RJ, Firestone GL. DEVD‐NucView488: a novel class of enzyme substrates for real‐time detection of caspase‐3 activity in live cells. FASEB J 2008; 22:2243-52. [DOI: 10.1096/fj.07-099234] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Hui Cen
- Biotium, Inc.Hayward CaliforniaUSA
| | - Fei Mao
- Biotium, Inc.Hayward CaliforniaUSA
| | - Ida Aronchik
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeley CaliforniaUSA
| | | | - Gary L. Firestone
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeley CaliforniaUSA
| |
Collapse
|
30
|
Jump SM, Kung J, Staub R, Kinseth MA, Cram EJ, Yudina LN, Preobrazhenskaya MN, Bjeldanes LF, Firestone GL. N-Alkoxy derivatization of indole-3-carbinol increases the efficacy of the G1 cell cycle arrest and of I3C-specific regulation of cell cycle gene transcription and activity in human breast cancer cells. Biochem Pharmacol 2007; 75:713-24. [PMID: 18023427 DOI: 10.1016/j.bcp.2007.09.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 09/25/2007] [Accepted: 09/27/2007] [Indexed: 11/30/2022]
Abstract
Indole-3-carbinol (I3C), a naturally occurring component of Brassica vegetables, such as cabbage, broccoli, and Brussels sprouts, induces a G1 cell cycle arrest of human breast cancer cells. Structure-activity relationships of I3C that mediate this anti-proliferative response were investigated using synthetic and natural I3C derivatives that contain substitutions at the indole nitrogen. Nitrogen substitutions included N-alkoxy substituents of one to four carbons in length, which inhibit dehydration and the formation of the reactive indolenine. Analysis of growth and cell cycle arrest of indole-treated human breast cancer cells revealed a striking increase in efficacy of the N-alkoxy I3C derivatives that is significantly enhanced by the presence of increasing carbon lengths of the N-alkoxy substituents. Compared to I3C, the half maximal growth arrest responses occurred at 23-fold lower indole concentration for N-methoxy I3C, 50-fold lower concentration for N-ethoxy I3C, 217-fold lower concentration for N-propoxy I3C, and 470-fold lower concentration for N-butoxy I3C. At these lower concentrations, each of the N-alkoxy substituted compounds induced the characteristic I3C response in that CDK6 gene expression, CDK6 promoter activity, and CDK2 specific enzymatic activity for its retinoblastoma protein substrate were strongly down-regulated. 3-Methoxymethylindole and 3-ethoxymethylindole were approximately as bioactive as I3C, whereas both tryptophol and melatonin failed to induce the cell cycle arrest, showing the importance of the C-3 hydroxy methyl substituent on the indole ring. Taken together, our study establishes the first I3C structure-activity relationship for cytostatic activities, and implicates I3C-based N-alkoxy derivatives as a novel class of potentially more potent experimental therapeutics for breast cancer.
Collapse
Affiliation(s)
- Sarah M Jump
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA 94720-3200, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Buse P, Maiyar AC, Failor KL, Tran S, Leong MLL, Firestone GL. The stimulus-dependent co-localization of serum- and glucocorticoid-regulated protein kinase (Sgk) and Erk/MAPK in mammary tumor cells involves the mutual interaction with the importin-alpha nuclear import protein. Exp Cell Res 2007; 313:3261-75. [PMID: 17692313 PMCID: PMC3422670 DOI: 10.1016/j.yexcr.2007.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 06/21/2007] [Accepted: 07/03/2007] [Indexed: 01/04/2023]
Abstract
In Con8 rat mammary epithelial tumor cells, indirect immunofluorescence revealed that Sgk (serum- and glucocorticoid-regulated kinase) and Erk/MAPK (extracellular signal-regulated protein kinase/mitogen activated protein kinase) co-localized to the nucleus in serum-treated cells and to the cytoplasmic compartment in cells treated with the synthetic glucocorticoid dexamethasone. Moreover, the subcellular distribution of the importin-alpha nuclear transport protein was similarly regulated in a signal-dependent manner. In vitro GST-pull down assays revealed the direct interaction of importin-alpha with either Sgk or Erk/MAPK, while RNA interference knockdown of importin-alpha expression disrupted the localization of both Sgk and Erk into the nucleus of serum-treated cells. Wild type or kinase dead forms of Sgk co-immunoprecipitated with Erk/MAPK from either serum- or dexamethasone-treated mammary tumor cells, suggesting the existence of a protein complex containing both kinases. In serum-treated cells, nucleus residing Sgk and Erk/MAPK were both hyperphosphorylated, indicative of their active states, whereas, in dexamethasone-treated cells Erk/MAPK, but not Sgk, was in its inactive hypophosphorylated state. Treatment with a MEK inhibitor, which inactivates Erk/MAPK, caused the relocalization of both Sgk and ERK to the cytoplasm. We therefore propose that the signal-dependent co-localization of Sgk and Erk/MAPK mediated by importin-alpha represents a new pathway of signal integration between steroid and serum/growth factor-regulated pathways.
Collapse
Affiliation(s)
- Patricia Buse
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA 94720-3200, USA
| | | | | | | | | | | |
Collapse
|
32
|
Failor KL, Desyatnikov Y, Finger LA, Firestone GL. Glucocorticoid-induced degradation of glycogen synthase kinase-3 protein is triggered by serum- and glucocorticoid-induced protein kinase and Akt signaling and controls beta-catenin dynamics and tight junction formation in mammary epithelial tumor cells. Mol Endocrinol 2007; 21:2403-15. [PMID: 17595317 DOI: 10.1210/me.2007-0143] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Glucocorticoid hormones stimulate adherens junction and tight junction formation in Con8 mammary epithelial tumor cells and induce the production of a stable nonphosphorylated beta-catenin protein localized exclusively to the cell periphery. Glycogen synthase kinase-3 (GSK3) phosphorylation of beta-catenin is known to trigger the degradation of this adherens junction protein, suggesting that steroid-activated cascades may be targeting this protein kinase. We now demonstrate that treatment with the synthetic glucocorticoid dexamethasone induces the ubiquitin-26S proteasome-mediated degradation of GSK3 protein with no change in GSK3 transcript levels. In transfected cells, deletion of the N-terminal nine amino acids or mutation of the serine-9 phosphorylation site on GSK3-beta prevented its glucocorticoid-induced degradation. Expression of stabilized GSK3 mutant proteins ablated the glucocorticoid-induced tight junction sealing and resulted in production of a nonphosphorylated beta-catenin that localizes to both the nucleus and the cell periphery in steroid-treated cells. Serine-9 on GSK3 can be phosphorylated by Sgk (serum- and glucocorticoid-induced protein kinase) and by Akt. Expression of dominant-negative forms of either Sgk- or Akt-inhibited glucocorticoid induced GSK3 ubiquitination and degradation and disrupted the dexamethasone-induced effects on beta-catenin dynamics. Furthermore, the steroid-induced tight junction sealing is attenuated in cells expressing dominant-negative forms of either Sgk or Akt, although the effect of blunting Sgk signaling was significantly greater. Taken together, we have uncovered a new cellular cascade in which Sgk and Akt trigger the glucocorticoid-regulated phosphorylation, ubiquitination, and degradation of GSK3, which alters beta-catenin dynamics, leading to the formation of adherens junctions and tight junction sealing.
Collapse
Affiliation(s)
- Kim L Failor
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3200, USA
| | | | | | | |
Collapse
|
33
|
Rubenstein NM, Callahan JA, Lo DH, Firestone GL. Selective glucocorticoid control of Rho kinase isoforms regulate cell-cell interactions. Biochem Biophys Res Commun 2007; 354:603-7. [PMID: 17240358 PMCID: PMC1817781 DOI: 10.1016/j.bbrc.2007.01.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Accepted: 01/05/2007] [Indexed: 01/20/2023]
Abstract
The two Rho kinase isoforms ROCK1 and ROCK2 are downstream effectors of the small GTPase RhoA, although relatively little is known about potential isoform specific functions or the selective control of their cellular activities. Using Con8 rat mammary epithelial cells, we show that the synthetic glucocorticoid dexamethasone strongly stimulates the level of ROCK2 protein, which accounts for the increase in total cellular ROCK2 activity, whereas, steroid treatment down-regulated ROCK1 specific kinase activity without altering ROCK1 protein levels. In Con8 cells, the glucocorticoid induced formation of tight junctions requires the steroid-mediated down-regulation RhoA and function of the RhoA antagonist Rnd3. Treatment with the ROCK inhibitor Y-27632 ablated both the glucocorticoid-induced and Rnd3-mediated stimulation in tight junction sealing. Taken together, our results demonstrate that the expression and activity of ROCK1 and ROCK2 can be uncoupled in a signal-dependent manner, and further implicate a new function for ROCK2 in the steroid control of tight junction dynamics.
Collapse
Affiliation(s)
| | | | | | - Gary L. Firestone
- * Corresponding author: Gary L. Firestone, Dept. of Molecular and Cell Biology, 591 LSA, University of California at Berkeley, Berkeley, CA 94720-3200, Tel: (510) 642-8319; Fax: (510) 643-6791;
| |
Collapse
|
34
|
Hsu JC, Dev A, Wing A, Brew CT, Bjeldanes LF, Firestone GL. Indole-3-carbinol mediated cell cycle arrest of LNCaP human prostate cancer cells requires the induced production of activated p53 tumor suppressor protein. Biochem Pharmacol 2006; 72:1714-23. [PMID: 16970927 DOI: 10.1016/j.bcp.2006.08.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Revised: 08/14/2006] [Accepted: 08/15/2006] [Indexed: 10/24/2022]
Abstract
Indole-3-carbinol (I3C), a dietary compound found naturally in cruciferous vegetables of the Brassica genus such as broccoli and brussels sprouts, induces a G1 growth arrest of human reproductive cancer cells. We previously reported that in LNCaP prostate cancer cells, I3C down-regulated cyclin-dependent kinase (CDK) 2 activity. In our current study, Western blotting and quantitative RT-PCR demonstrated that I3C treatment increased both the transcripts and protein levels of the CDK2 inhibitor p21(waf1/cip1) (p21). Transfection of luciferase reporter plasmids containing wild-type and mutated p21 promoter fragments revealed that I3C induced p21 gene transcription through a p53 DNA binding element. Oligonucleotide precipitation showed that I3C increased the level of activated p53 nuclear protein that is competent to bind its DNA target site on the p21 promoter. Ablation of p53 production using short interfering RNA (siRNA) prevented that the I3C induced G1 arrest and up-regulation of p21 expression. Western blots using p53 phospho-specific antibodies revealed that I3C treatment increased the levels of three phosphorylated forms of p53 (Ser15, Ser37, Ser392) that are known to contribute to p53 protein stability and greater transactivation potential. Taken together, our results establish that the I3C induced G1 arrest of human prostate cancer cells requires the induced production of the activated phosphorylated forms of p53, which stimulate transcription of the CDK2 inhibitor p21.
Collapse
Affiliation(s)
- Jocelyn C Hsu
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, The University of California at Berkeley, Berkeley, CA 94720, USA
| | | | | | | | | | | |
Collapse
|
35
|
Sundar SN, Kerekatte V, Equinozio CN, Doan VB, Bjeldanes LF, Firestone GL. Indole-3-Carbinol Selectively Uncouples Expression and Activity of Estrogen Receptor Subtypes in Human Breast Cancer Cells. Mol Endocrinol 2006; 20:3070-82. [PMID: 16901971 DOI: 10.1210/me.2005-0263] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
Estrogen-responsive breast cancer cells, such as MCF7 and T47D cells, express both estrogen receptor (ER)-α (ERα) and ERβ. Indole-3-carbinol (I3C) strongly down-regulated ERα protein and transcript levels, without altering the level of ERβ protein, in both cell lines. In cells transfected with the ERα promoter linked to a luciferase gene reporter, I3C ablated ERα promoter activity. Propyl pyrazole triol (PPT) is a highly selective ERα agonist, whereas, 17β-estradiol activates both ERα and ERβ. I3C treatment inhibited the PPT- and 17β-estradiol-induced proliferation of breast cancer cells, disrupted the PPT and 17β-estradiol stimulation of estrogen response element (ERE)-driven reporter plasmid activity as well as of endogenous progesterone receptor transcripts. Using an in vitro ERE binding assay, I3C was shown to inhibit the level of functional ERα and stimulated the level of ERE binding ERβ even though the protein levels of this receptor remained constant. In ERα−/ERβ+ MDA-MB-231 breast cancer cells, I3C treatment stimulated a 6-fold increase in binding of ERβ to the ERE. I3C also induced ERE- and activator protein 1-driven reporter plasmid activities in the absence of an ER agonist, suggesting that ERβ is activated in indole-treated cells. Taken together, our results demonstrate that the expression and function of ERα and ERβ can be uncoupled by I3C with a key cellular consequence being a significantly higher ERβ:ERα ratio that is generally highly associated with antiproliferative status of human breast cancer cells.
Collapse
Affiliation(s)
- Shyam N Sundar
- Department of Molecular and Cell Biology, 591 LSA, University of California at Berkeley, Berkeley, California 94720-3200 USA
| | | | | | | | | | | |
Collapse
|
36
|
Gong Y, Sohn H, Xue L, Firestone GL, Bjeldanes LF. 3,3'-Diindolylmethane is a novel mitochondrial H(+)-ATP synthase inhibitor that can induce p21(Cip1/Waf1) expression by induction of oxidative stress in human breast cancer cells. Cancer Res 2006; 66:4880-7. [PMID: 16651444 DOI: 10.1158/0008-5472.can-05-4162] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Epidemiologic evidence suggests that high dietary intake of Brassica vegetables, such as broccoli, cabbage, and Brussels sprouts, protects against tumorigenesis in multiple organs. 3,3'-Diindolylmethane, one of the active products derived from Brassica vegetables, is a promising antitumor agent. Previous studies in our laboratory showed that 3,3'-diindolylmethane induced a G(1) cell cycle arrest in human breast cancer MCF-7 cells by a mechanism that included increased expression of p21. In the present study, the upstream events leading to p21 overexpression were further investigated. We show for the first time that 3,3'-diindolylmethane is a strong mitochondrial H(+)-ATPase inhibitor (IC(50) approximately 20 micromol/L). 3,3'-Diindolylmethane treatment induced hyperpolarization of mitochondrial inner membrane, decreased cellular ATP level, and significantly stimulated mitochondrial reactive oxygen species (ROS) production. ROS production, in turn, led to the activation of stress-activated pathways involving p38 and c-Jun NH(2)-terminal kinase. Using specific kinase inhibitors (SB203580 and SP600125), we showed the central role of p38 and c-Jun NH(2)-terminal kinase (JNK) pathways in 3,3'-diindolylmethane-induced p21 mRNA transcription. In addition, antioxidants significantly attenuated 3,3'-diindolylmethane-induced activation of p38 and JNK and induction of p21, indicating that oxidative stress is the major trigger of these events. To further support the role of ROS in 3,3'-diindolylmethane-induced p21 overexpression, we showed that 3,3'-diindolylmethane failed to induce p21 overexpression in mitochondrial respiratory chain deficient rho(0) MCF-7 cells, in which 3,3'-diindolylmethane did not stimulate ROS production. Thus, we have established the critical role of enhanced mitochondrial ROS release in 3,3'-diindolylmethane-induced p21 up-regulation in human breast cancer cells.
Collapse
Affiliation(s)
- Yixuan Gong
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720, USA
| | | | | | | | | |
Collapse
|
37
|
Riby JE, Xue L, Chatterji U, Bjeldanes EL, Firestone GL, Bjeldanes LF. Activation and potentiation of interferon-gamma signaling by 3,3'-diindolylmethane in MCF-7 breast cancer cells. Mol Pharmacol 2006; 69:430-9. [PMID: 16267208 DOI: 10.1124/mol.105.017053] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
3,3'-Diindolylmethane (DIM), a natural autolytic product in plants of the Brassica genus, including broccoli, cauliflower, and Brussels sprouts, exhibits promising cancer protective activities, especially against mammary neoplasia in animal models. We observed previously that DIM induced a G(1) cell-cycle arrest and strong induction of cell-cycle inhibitor p21 expression and promoter activity in both estrogen-responsive and -independent breast cancer cell lines. We showed recently that DIM up-regulates the expression of interferon gamma (IFNgamma) in human MCF-7 breast cancer cells. This novel effect may contribute to the anticancer effects of DIM because IFNgamma plays an important role in preventing the development of primary and transplanted tumors. In this study, we observed that DIM activated the IFNgamma signaling pathway in human breast cancer cells. DIM activated the expression of the IFNgamma receptor (IFNGR1) and IFNgamma-responsive genes p56- and p69-oligoadenylate synthase (OAS). In cotreatments with IFNgamma, DIM produced an additive activation of endogenous p69-OAS and of an OAS-Luc reporter and a synergistic activation of a GAS-Luc reporter. DIM synergistically augmented the IFNgamma induced phosphorylation of signal transducer and activator of transcription factor 1, further evidence of DIM activation of the IFNgamma pathway. DIM and IFNgamma produced an additive inhibition of cell proliferation and a synergistic increase in levels of major histocompatibility complex class-1 (MHC-1) expression, accompanied by increased levels of mRNAs of MHC-1-associated proteins and transporters. These results reveal novel immune activating and potentiating activities of DIM in human tumor cells that may contribute to the established effectiveness of this dietary indole against various tumors types.
Collapse
Affiliation(s)
- Jacques E Riby
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, 94720-3104, USA
| | | | | | | | | | | |
Collapse
|
38
|
Gong Y, Firestone GL, Bjeldanes LF. 3,3'-diindolylmethane is a novel topoisomerase IIalpha catalytic inhibitor that induces S-phase retardation and mitotic delay in human hepatoma HepG2 cells. Mol Pharmacol 2005; 69:1320-7. [PMID: 16385077 DOI: 10.1124/mol.105.018978] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Epidemiological evidence suggests that high consumption of Brassica genus vegetables, such as broccoli, cabbage, and Brussels sprouts, is very effective in reducing the risks of several types of cancers. 3,3'-Diindolylmethane (DIM), one of the most abundant and biologically active dietary compounds derived from Brassica genus vegetables, displays remarkable antitumor activity against several experimental tumors. In the present study, we demonstrate for the first time that DIM is a novel catalytic topoisomerase IIalpha inhibitor. In supercoiled DNA relaxation assay and kinetoplast DNA decatenation assay, DIM strongly inhibited DNA topoisomerase IIalpha and also partially inhibited DNA topoisomerases I and IIbeta. DIM did not stabilize DNA cleavage complex and did not prevent etoposide-induced DNA cleavage complex formation. Further experiments showed that DIM inhibited topoisomerase IIalpha-catalyzed ATP hydrolysis, which is a necessary step for the enzyme turnover. In cultured human hepatoma HepG2 cells, DIM blocked DNA synthesis and mitosis in a concentration-dependent manner, which was consistent with the outcome of topoisomerase inhibition in these cell-cycle phases. Our results identified a new mode of action for this intriguing dietary component that might be exploited for therapeutic development.
Collapse
Affiliation(s)
- Yixuan Gong
- Department of Nutritional Sciences and Toxicology, 119 Morgan Hall, University of California, Berkeley, CA 94720-3104, USA
| | | | | |
Collapse
|
39
|
Chang X, Firestone GL, Bjeldanes LF. Inhibition of growth factor-induced Ras signaling in vascular endothelial cells and angiogenesis by 3,3'-diindolylmethane. Carcinogenesis 2005; 27:541-50. [PMID: 16199440 DOI: 10.1093/carcin/bgi230] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
3,3'-Diindolylmethane (DIM), an indole derivative produced on consumption of broccoli and other cruciferous vegetables, has been shown to have multiple anticancer effects in both in vivo and in vitro models. The present study was carried out to clarify the mechanism of DIM's antiangiogenic activity. We found that DIM can inhibit vascular endothelial growth factor (VEGF)-induced cell proliferation and DNA synthesis in human umbilical vascular endothelial cells (HUVECs). Consistent with this inhibition, VEGF-induced extracellular signal-regulated kinase (ERK1/2) phosphorylation was greatly reduced. However, VEGF receptor phosphorylation induced by VEGF was not affected by DIM, indicating that DIM does not exert a direct and specific effect on the tyrosine kinase activity of this receptor. Further studies showed that DIM had a similar inhibitory effect on ERK1/2 phosphorylation induced by a variety of growth factors. Furthermore, Ras-GTP content, which dramatically increased after HUVECs were challenged by either individual growth factors or serum, was reduced by approximately 80% with 25 muM DIM treatment, which in turn resulted in the reduced activities of Raf and MEK, culminating in the drop of ERK1/2 activation. Overexpression of constitutively active GTPase mutant, Ras G12V, in HUVECs reversed the inhibitory effect of DIM on ERK1/2 activation. In a rodent Matrigel plug model, the presence of DIM strongly reduced VEGF-induced neovascularization, indicating that DIM is active in vivo. These data provide evidence that DIM inhibits Ras signaling induced by VEGF and other growth factors, which interferes with its downstream biological effects necessary for angiogenesis.
Collapse
Affiliation(s)
- Xiaofei Chang
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | | | | |
Collapse
|
40
|
Brew CT, Aronchik I, Hsu JC, Sheen JH, Dickson RB, Bjeldanes LF, Firestone GL. Indole-3-carbinol activates the ATM signaling pathway independent of DNA damage to stabilize p53 and induce G1 arrest of human mammary epithelial cells. Int J Cancer 2005; 118:857-68. [PMID: 16152627 DOI: 10.1002/ijc.21445] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The phytochemical indole-3-carbinol (I3C), from cruciferous vegetables such as broccoli, has been shown to elicit a potent anti-proliferative response in human breast cancer cell lines. Treatment of the immortalized human mammary epithelial cell line MCF10A with I3C induced a G1 cell cycle arrest, elevated p53 tumor suppressor protein levels and stimulated expression of downstream transcriptional target, p21. I3C treatment also elevated p53 levels in several breast cancer cell lines that express mutant p53. I3C did not arrest MCF10A cells stably transfected with dominant-negative p53, establishing a functional requirement for p53. Cell fractionation and immunolocalization studies revealed a large fraction of stabilized p53 protein in the nucleus of I3C-treated MCF10A cells. With I3C treatment, phosphatidyl-inositol-3-kinase family member ataxia telangiectasia-mutated (ATM) was phosphorylated, as were its substrates p53, CHK2 and BRCA1. Phosphorylation of p53 at the N-terminus has previously been shown to disrupt the interaction between p53 and its ubiquitin ligase, MDM2, and therefore stabilizing p53. Coimmunoprecipitation analysis revealed that I3C reduced by 4-fold the level of MDM2 protein that associated with p53. The p53-MDM2 interaction and absence of p21 production were restored in cells treated with I3C and the ATM inhibitor wortmannin. Significantly, I3C does not increase the number of 53BP1 foci or H2AX phosphorylation, indicating that ATM is activated independent of DNA double-strand breaks. Taken together, our results demonstrate that I3C activates ATM signaling through a novel pathway to stimulate p53 phosphorylation and disruption of the p53-MDM2 interaction, which releases p53 to induce the p21 CDK inhibitor and a G1 cell cycle arrest.
Collapse
Affiliation(s)
- Christine T Brew
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA 94720-3200, USA
| | | | | | | | | | | | | |
Collapse
|
41
|
Hsu JC, Zhang J, Dev A, Wing A, Bjeldanes LF, Firestone GL. Indole-3-carbinol inhibition of androgen receptor expression and downregulation of androgen responsiveness in human prostate cancer cells. Carcinogenesis 2005; 26:1896-904. [PMID: 15958518 DOI: 10.1093/carcin/bgi155] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Indole-3-carbinol (I3C), a naturally occurring compound found in vegetables of the Brassica genus, such as broccoli and cabbage, is a promising anticancer agent previously shown to induce a G(1) cell-cycle arrest in the cells of human lymph node carcinoma of prostate (LNCaP) through regulation of specific G(1)-acting cell-cycle components. Since the androgen receptor (AR) mediates proliferation and differentiation in the prostate and is expressed in nearly all human prostate cancers, the effects of I3C on AR expression and function were examined in LNCaP cells. Immunoblot and quantitative RT-PCR assays revealed that I3C inhibited the expression of AR protein and mRNA levels within 12 h of indole treatment. I3C downregulated the reporter activity of LNCaP cells transiently transfected with an AR promoter-luciferase plasmid, demonstrating that a unique response to I3C is the inhibition of AR promoter activity. In contrast to I3C, the natural I3C dimerization product 3,3'-diindolylmethane, which acts as an androgen antagonist, had no effect on AR expression. To determine the functional significance of the I3C-inhibited expression of AR, the AR-regulated prostate specific antigen (PSA) was utilized as a downstream indicator. I3C downregulated the expression of PSA transcripts and protein levels and inhibited PSA promoter activity, as well as that of a minimal androgen responsive element containing reporter plasmid. Expression of exogenous AR prevented the I3C disruption of androgen-induced PSA expression. Taken together, our results demonstrate that I3C represses AR expression and responsiveness in LNCaP cells as a part of its antiproliferative mechanism.
Collapse
Affiliation(s)
- Jocelyn C Hsu
- Department of Molecular and Cell Biology, The University of California at Berkeley, CA 94720, USA
| | | | | | | | | | | |
Collapse
|
42
|
Xue L, Firestone GL, Bjeldanes LF. DIM stimulates IFNgamma gene expression in human breast cancer cells via the specific activation of JNK and p38 pathways. Oncogene 2005; 24:2343-53. [PMID: 15735741 DOI: 10.1038/sj.onc.1208434] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
3,3'-Diindolylmethane (DIM) is a promising anticancer agent derived from Brassica vegetables, but the mechanisms of DIM action are largely unknown. We have shown that DIM can upregulate the expression and stimulate the secretion of interferon-gamma (IFNgamma) in the human MCF-7 breast cancer cell line. This novel effect may provide important clues to explain the anticancer effects of DIM because it is well known that IFNgamma plays an important role in preventing the development of primary and transplanted tumors. Utilizing promoter deletions, we show here that the region between -108 and -36 bp in the IFNgamma promoter, which contains two conserved and essential regulatory elements, is required for DIM-induced IFNgamma expression. DIM activates both JNK and p38 pathways, induces the phosphorylation of c-Jun and ATF-2, and increases the binding of the homodimer or heterodimer of c-Jun/ATF-2 to the proximal AP-1.CREB-ATF-binding element. Moreover, studies with specific enzyme inhibitors showed that up-stream Ca2+-dependent kinase(s) is required for the inducing effects of DIM in MCF-7 cells. These results establish that DIM-induced IFNgamma expression in human breast tumor cells is mediated by activation of both JNK and p38 pathways, which is ultimately dependent on intracellular calcium signaling.
Collapse
Affiliation(s)
- Ling Xue
- Department of Nutritional Sciences and Toxicology, University of California, 119 Morgan Hall, Berkeley, CA 94720-3104, USA
| | | | | |
Collapse
|
43
|
Rubenstein NM, Chan JF, Kim JY, Hansen SH, Firestone GL. Rnd3/RhoE induces tight junction formation in mammary epithelial tumor cells. Exp Cell Res 2005; 305:74-82. [PMID: 15777789 DOI: 10.1016/j.yexcr.2004.12.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2004] [Revised: 11/12/2004] [Accepted: 12/10/2004] [Indexed: 10/25/2022]
Abstract
Glucocorticoid hormones stimulate adherens and tight junction formation in Con8 mammary epithelial tumor cells through a multistep process in which the membrane organization of structural apical junction proteins and tight junction sealing is controlled by specific signal transduction components. We have previously shown that dexamethasone stimulation of apical junction formation requires down-regulation of the small GTPase RhoA. Here we identified Rnd3/RhoE, a GTPase-deficient Rho family member and RhoA antagonist, as a key regulator of apical junction dynamics. Exogenously expressed Rnd3/RhoE co-localized with actin at the cell periphery and induced the localization of the adherens junction protein beta-catenin and the tight junction protein ZO-1 to sites of cell-cell contact, and led to the formation of highly sealed tight junctions. Treatment with glucocorticoids was not required to achieve complete apical junction remodeling. Consistent with Rnd3/RhoE acting as an antagonist of RhoA, expression of Rnd3/RhoE rescued the disruptive effects of constitutively active RhoA on apical junction organization. Our results demonstrate a new role for the Rho family member Rnd3/RhoE in regulating the assembly of the apical junction complex and tight junction sealing.
Collapse
Affiliation(s)
- Nicola M Rubenstein
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California, Berkeley, CA 94720-3200, USA
| | | | | | | | | |
Collapse
|
44
|
Garcia HH, Brar GA, Nguyen DHH, Bjeldanes LF, Firestone GL. Indole-3-Carbinol (I3C) Inhibits Cyclin-dependent Kinase-2 Function in Human Breast Cancer Cells by Regulating the Size Distribution, Associated Cyclin E Forms, and Subcellular Localization of the CDK2 Protein Complex. J Biol Chem 2005; 280:8756-64. [PMID: 15611077 DOI: 10.1074/jbc.m407957200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Indole-3-carbinol (I3C), a dietary compound found in cruciferous vegetables, induces a robust inhibition of CDK2 specific kinase activity as part of a G1 cell cycle arrest of human breast cancer cells. Treatment with I3C causes a significant shift in the size distribution of the CDK2 protein complex from an enzymatically active 90 kDa complex to a larger 200 kDa complex with significantly reduced kinase activity. Co-immunoprecipitations revealed an increased association of both a 50 kDa cyclin E and a 75 kDa cyclin E immunoreactive protein with the CDK2 protein complex under I3C-treated conditions, whereas the 90 kDa CDK2 protein complexes detected in proliferating control cells contain the lower molecular mass forms of cyclin E. I3C treatment caused no change in the level of CDK2 inhibitors (p21, p27) or in the inhibitory phosphorylation states of CDK2. The effects of I3C are specific for this indole and not a consequence of the cell cycle arrest because treatment of MCF-7 breast cancer cells with either the I3C dimerization product DIM or the anti-estrogen tamoxifen induced a G1 cell cycle arrest with no changes in the associated cyclin E or subcellular localization of the CDK2 protein complex. Taken together, our results have uncovered a unique effect of I3C on cell cycle control in which the inhibition of CDK2 kinase activity is accompanied by selective alterations in cyclin E composition, size distribution, and subcellular localization of the CDK2 protein complex.
Collapse
Affiliation(s)
- Hanh H Garcia
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, The University of California at Berkeley, Berkeley, California 94720, USA
| | | | | | | | | |
Collapse
|
45
|
Dalessandri KM, Firestone GL, Fitch MD, Bradlow HL, Bjeldanes LF. Pilot study: effect of 3,3'-diindolylmethane supplements on urinary hormone metabolites in postmenopausal women with a history of early-stage breast cancer. Nutr Cancer 2005; 50:161-7. [PMID: 15623462 DOI: 10.1207/s15327914nc5002_5] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Dietary indoles, present in Brassica plants such as cabbage, broccoli, and Brussels sprouts, have been shown to provide potential protection against hormone-dependent cancers. 3,3'-Diindolylmethane (DIM) is under study as one of the main protective indole metabolites. Postmenopausal women aged 50-70 yr from Marin County, California, with a history of early-stage breast cancer, were screened for interest and eligibility in this pilot study on the effect of absorbable DIM (BioResponse-DIM) supplements on urinary hormone metabolites. The treatment group received daily DIM (108 mg DIM/day) supplements for 30 days, and the control group received a placebo capsule daily for 30 days. Urinary metabolite analysis included 2-hydroxyestrone (2-OHE1), 16-alpha hydroxyestrone (16alpha-OHE1), DIM, estrone (El), estradiol(E2), estriol (E3), 6beta-hydroxycortisol (6beta-OHC), and cortisol in the first morning urine sample before intervention and 31 days after intervention. Nineteen women completed the study,for a total of 10 in the treatment group and 9 in the placebo group. DIM-treated subjects, relative to placebo, showed a significant increase in levels of2-OHE1 (P=0. 020), DIM (P =0. 045), and cortisol (P = 0.039), and a nonsignificant increase of 47% in the 2-OHE1/16alpha-OHE1 ratio from 1.46 to 2.14 (P=0.059). In this pilot study, DIM increased the 2-hydroxylation of estrogen urinary metabolites.
Collapse
Affiliation(s)
- Kathie M Dalessandri
- Department of Molecular and Cell Biology, University of California, Berkeley, 94720-3200, USA
| | | | | | | | | |
Collapse
|
46
|
Chang X, Tou JC, Hong C, Kim HA, Riby JE, Firestone GL, Bjeldanes LF. 3,3'-Diindolylmethane inhibits angiogenesis and the growth of transplantable human breast carcinoma in athymic mice. Carcinogenesis 2005; 26:771-8. [PMID: 15661811 DOI: 10.1093/carcin/bgi018] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Studies have linked the consumption of broccoli and other cruciferous vegetables to a reduced risk of breast cancer. The phytochemical indole-3-carbinol (I3C), present in cruciferous vegetables, and its major acid-catalyzed reaction product 3,3'-diindolylmethane (DIM) have bioactivities relevant to the inhibition of carcinogenesis. In this study, the effect of DIM on angiogenesis and tumorigenesis in a rodent model was investigated. We found that DIM produced a concentration-dependent decrease in proliferation, migration, invasion and capillary tube formation of cultured human umbilical vein endothelial cells (HUVECs). Consistent with its antiproliferative effect, which was significant at only 5 microM DIM, this indole caused a G1 cell cycle arrest in actively proliferating HUVECs. Furthermore, DIM downregulated the expression of cyclin-dependent kinases 2 and 6 (CDK2, CDK6), and upregulated the expression of CDK inhibitor, p27(Kip1), in HUVECs. We observed further in a complementary in vivo Matrigel plug angiogenesis assay that, compared with vehicle control, neovascularization was inhibited up to 76% following the administration of 5 mg/kg DIM to female C57BL/6 mice. Finally, this dose of DIM also inhibited the growth of human MCF-7 cell tumor xenografts by up to 64% in female athymic (nu/nu) mice, compared with the vehicle control. This is the first study to show that DIM can strongly inhibit the development of human breast tumor in a xenograft model and to provide evidence for the antiangiogenic properties of this dietary indole.
Collapse
Affiliation(s)
- Xiaofei Chang
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | | | | | | | | | | | | |
Collapse
|
47
|
Chatterji U, Riby JE, Taniguchi T, Bjeldanes EL, Bjeldanes LF, Firestone GL. Indole-3-carbinol stimulates transcription of the interferon gamma receptor 1 gene and augments interferon responsiveness in human breast cancer cells. Carcinogenesis 2004; 25:1119-28. [PMID: 14988219 DOI: 10.1093/carcin/bgh121] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Indole-3-carbinol (I3C), a naturally occurring compound of Brassica vegetables, has promising anticancer properties and activates an anti-proliferative pathway that induces a G1 cell cycle arrest of human breast cancer cells. A microarray analysis of I3C treated versus untreated MCF-7 breast cancer cells revealed that I3C increased expression of the interferon gamma receptor 1 (IFNgammaR1). Western blot and RT-PCR analysis demonstrated that I3C strongly and rapidly stimulated IFNgammaR1 gene expression. Transfection of a series of 5' deletion constructs of the IFNgammaR1 reporter plasmids revealed that I3C significantly stimulates the promoter activity of the IFNgammaR1 and uncovered an I3C-responsive region between -540 and -240 bp of the IFNgammaR1 promoter. I3C stimulation of the IFNgammaR1 expression suggests that indole treatment should enhance IFNgamma responsiveness in breast cancer cells. A combination of I3C and IFNgamma synergistically activated STAT1 proteins by increasing phosphorylation at the Tyr-701 site. In addition, I3C and IFNgamma together more effectively induced a G1 cell cycle arrest and stimulated expression of the p21(Waf1/Cip1) cell cycle inhibitor, compared with the effects of either agent alone. Our results suggest that one mechanism by which I3C mediates these anticancer effects is by stimulating expression of the IFNgammaR1 and augmenting the IFNgamma response in MCF-7 human breast cancer cells.
Collapse
Affiliation(s)
- Urmi Chatterji
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA 94720-3200, USA
| | | | | | | | | | | |
Collapse
|
48
|
Paruthiyil S, Parmar H, Kerekatte V, Cunha GR, Firestone GL, Leitman DC. Estrogen receptor beta inhibits human breast cancer cell proliferation and tumor formation by causing a G2 cell cycle arrest. Cancer Res 2004; 64:423-8. [PMID: 14729654 DOI: 10.1158/0008-5472.can-03-2446] [Citation(s) in RCA: 434] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Studies indicate that estrogen receptor (ER) alpha mediates breast cancer-promoting effects of estrogens. The role of ERbeta in breast cancer is unknown. Elucidating the role of ERbeta in the pathogenesis of breast cancer is important because many human breast tumors express both ERalpha and ERbeta. We show that adenovirus-mediated expression of ERbeta changes the phenotype of ERalpha-positive MCF-7 cells. Estradiol increases cell proliferation and causes tumor formation of MCF-7 cells expressing only ERalpha. In contrast, introducing ERbeta into MCF-7 cells causes an inhibition of proliferation in vitro and prevents tumor formation in a mouse xenograft model in response to estradiol. ERbeta inhibits proliferation by repressing c-myc, cyclin D1, and cyclin A gene transcription, and increasing the expression of p21(Cip1) and p27(Kip1), which leads to a G(2) cell cycle arrest. These results demonstrate that ERalpha and ERbeta produce opposite effects in MCF-7 cells on cell proliferation and tumor formation. Natural or synthetic ERbeta-selective estrogens may lack breast cancer promoting properties exhibited by estrogens in hormone replacement regimens and may be useful for chemoprevention of breast cancer.
Collapse
|
49
|
Paruthiyil S, Parmar H, Kerekatte V, Cunha GR, Firestone GL, Leitman DC. Estrogen receptor beta inhibits human breast cancer cell proliferation and tumor formation by causing a G2 cell cycle arrest. Cancer Res 2004. [PMID: 14729654 DOI: 10.1016/s0140-6736(03)14596-5] [Citation(s) in RCA: 892] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Studies indicate that estrogen receptor (ER) alpha mediates breast cancer-promoting effects of estrogens. The role of ERbeta in breast cancer is unknown. Elucidating the role of ERbeta in the pathogenesis of breast cancer is important because many human breast tumors express both ERalpha and ERbeta. We show that adenovirus-mediated expression of ERbeta changes the phenotype of ERalpha-positive MCF-7 cells. Estradiol increases cell proliferation and causes tumor formation of MCF-7 cells expressing only ERalpha. In contrast, introducing ERbeta into MCF-7 cells causes an inhibition of proliferation in vitro and prevents tumor formation in a mouse xenograft model in response to estradiol. ERbeta inhibits proliferation by repressing c-myc, cyclin D1, and cyclin A gene transcription, and increasing the expression of p21(Cip1) and p27(Kip1), which leads to a G(2) cell cycle arrest. These results demonstrate that ERalpha and ERbeta produce opposite effects in MCF-7 cells on cell proliferation and tumor formation. Natural or synthetic ERbeta-selective estrogens may lack breast cancer promoting properties exhibited by estrogens in hormone replacement regimens and may be useful for chemoprevention of breast cancer.
Collapse
|
50
|
Leong H, Riby JE, Firestone GL, Bjeldanes LF. Potent Ligand-Independent Estrogen Receptor Activation by 3,3′-Diindolylmethane Is Mediated by Cross Talk between the Protein Kinase A and Mitogen-Activated Protein Kinase Signaling Pathways. Mol Endocrinol 2004; 18:291-302. [PMID: 14645498 DOI: 10.1210/me.2003-0196] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We investigated the mechanism of ligand-independent activation of the estrogen receptor (ER) by 3,3'-diindolylmethane (DIM), a promising anticancer agent derived from vegetables of the Brassica genus, in Ishikawa and HEC-1B human endometrial cancer cells. DIM stimulated the activity of an ER-responsive reporter by over 40-fold, equivalent to the maximum induction produced by estradiol (E2), whereas cotreatment of cells with the ER antagonist, ICI-182,780 (ICI), abolished the stimulatory effect of DIM. DIM also induced the expressions of the endogenous genes, TGF-alpha, alkaline phosphatase, and progesterone receptor similar to levels induced by E2. Induction of gene expression by DIM was inhibited by the protein synthesis inhibitor, cycloheximide. In addition, cotreatment of cells with the protein kinase A (PKA) inhibitor, H89, or the MAPK inhibitor, PD98059, reduced DIM activation of the ER by 75% and 50%, respectively. Simultaneous treatment of cells with both inhibitors completely abolished the effect of DIM. DIM stimulated MAPK activity and induced phosphorylation of the endogenous PKA target, cAMP response element binding protein (CREB), in a PKA-dependent manner. Expression of MCREB, a nonphosphorylatable CREB mutant, partially abolished activation of the ER by DIM. These results demonstrate that DIM is a mechanistically novel activator of the ER that requires PKA-dependent phosphorylation of CREB.
Collapse
Affiliation(s)
- Hoyee Leong
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720, USA
| | | | | | | |
Collapse
|