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Hsp70–Bag3 Module Regulates Macrophage Motility and Tumor Infiltration via Transcription Factor LITAF and CSF1. Cancers (Basel) 2022; 14:cancers14174168. [PMID: 36077705 PMCID: PMC9454964 DOI: 10.3390/cancers14174168] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 11/25/2022] Open
Abstract
Simple Summary Patients’ normal cells, such as lymphocytes, fibroblasts, or macrophages, can either suppress or facilitate tumor growth. Macrophages can infiltrate tumors and secrete molecules that enhance the proliferation of cancer cells and their invasion into neighboring tissues and blood. Here, we investigated the mechanism of action of a novel small molecule that suppresses the infiltration of macrophages into tumors and demonstrates potent anticancer activity. We identified the entire pathway that links the intracellular protein Hsp70, which is inhibited by this small molecule, with the macrophage motility system. This study will lay the basis for a novel approach to cancer treatment via targeting tumor-associated macrophages. Abstract The molecular chaperone Hsp70 has been implicated in multiple stages of cancer development. In these processes, a co-chaperone Bag3 links Hsp70 with signaling pathways that control cancer development. Recently, we showed that besides affecting cancer cells, Hsp70 can also regulate the motility of macrophages and their tumor infiltration. However, the mechanisms of these effects have not been explored. Here, we demonstrated that the Hsp70-bound co-chaperone Bag3 associates with a transcription factor LITAF that can regulate the expression of inflammatory cytokines and chemokines in macrophages. Via this interaction, the Hsp70–Bag3 complex regulates expression levels of LITAF by controlling its proteasome-dependent and chaperone-mediated autophagy-dependent degradation. In turn, LITAF regulates the expression of the major chemokine CSF1, and adding this chemokine to the culture medium reversed the effects of Bag3 or LITAF silencing on the macrophage motility. Together, these findings uncover the Hsp70–Bag3–LITAF–CSF1 pathway that controls macrophage motility and tumor infiltration.
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2
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Liu Q, Liu J, Huang X. Unraveling the mystery: How bad is BAG3 in hematological malignancies? Biochim Biophys Acta Rev Cancer 2022; 1877:188781. [PMID: 35985611 DOI: 10.1016/j.bbcan.2022.188781] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 10/15/2022]
Abstract
BAG3, also known as BIS and CAIR-1, interacts with Hsp70 via its BAG domain and with other molecules through its WW domain, PXXP repeats and IPV motifs. BAG3 can participate in major cellular pathways including apoptosis, autophagy, cytoskeleton structure, and motility by regulating the expression, location, and activity of its chaperone proteins. As a multifunctional protein, BAG3 is highly expressed in skeletal muscle, cardiomyocytes and multiple tumors, and its intracellular expression can be stimulated by stress. The functions and mechanisms of BAG3 in hematological malignancies have recently been a topic of interest. BAG3 has been confirmed to be involved in the development and chemoresistance of hematological malignancies and to act as a prognostic indicator. Modulation of BAG3 and its corresponding proteins has thus emerged as a promising therapeutic and experimental target. In this review, we consider the characteristics of BAG3 in hematological malignancies as a reference for further clinical and fundamental investigations.
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Affiliation(s)
- Qinghan Liu
- Department of Thoracic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China.
| | - Jinde Liu
- Department of Respiratory, Dandong Central Hospital, Dandong, Liaoning, China
| | - Xinyue Huang
- The First Hospital of China Medical University, Shenyang, Liaoning, China.
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3
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Liu T, Lin S, Du Y, Gong Y, Li S. SpBAG3 assisted WSSV infection in mud crab (Scylla paramamosain) by inhibiting apoptosis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 129:104349. [PMID: 35007655 DOI: 10.1016/j.dci.2022.104349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
The function of B-cell lymphoma-2 (Bcl-2) family proteins can be divided into two categories: anti-apoptotic and pro-apoptotic. As an anti-apoptotic protein, Bcl2-associated athanogene 3 (BAG3) plays a key role in regulating apoptosis, development, cell movement, and autophagy, and mediating the adaptability of cells to stimulation. However, SpBAG3 has not been reported in mud crab (Scylla paramamosain), and the regulatory effect of SpBAG3 on apoptosis in mud crab and its function in antiviral immunity is still unknown. In this study, SpBAG3 was found, and characterized, which encoded a total of 175 amino acid (molecular mass 19.3 kDa), including a specific conserved domain of the BAG family. SpBAG3 was significantly down-regulated at 0-48 h post-infection with WSSV in vivo. The antiviral effect of SpBAG3 was investigated using RNA interference. The results indicated that SpBAG3 might be involved in assisting the replication of WSSV in the host. SpBAG3 could change the mitochondrial membrane potential (△ψm), and affect cell apoptosis through mitochondrial apoptotic pathways. Therefore, the results of this study suggested that SpBAG3 could assist WSSV infection by inhibiting the apoptosis of the hemocytes in mud crab.
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Affiliation(s)
- Ting Liu
- Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou, 515063, China; Marine Biology Institute, Shantou University, Shantou, 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Shanmeng Lin
- Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou, 515063, China; Marine Biology Institute, Shantou University, Shantou, 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Yaoyao Du
- Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou, 515063, China; Marine Biology Institute, Shantou University, Shantou, 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China
| | - Yi Gong
- Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou, 515063, China; Marine Biology Institute, Shantou University, Shantou, 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China.
| | - Shengkang Li
- Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou, 515063, China; Marine Biology Institute, Shantou University, Shantou, 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China.
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4
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Guo J, Du X, Li C. BAG family proteins contributes to autophagy-mediated multidrug resistance of tumor. Clin Transl Oncol 2022; 24:1492-1500. [PMID: 35278199 DOI: 10.1007/s12094-022-02819-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 02/22/2022] [Indexed: 12/13/2022]
Abstract
Multidrug resistance (MDR) is a significant cause of tumor treatment failure. Accumulating evidence suggests that autophagy plays a significant role in the development of MDR. Autophagy is a conserved mechanism that maintains tumor homeostasis by removing damaged mitochondria. However, the specific regulatory mechanism is unclear. Here, we summarize recent studies on the role of autophagy in the development of MDR and the initiation of mitophagy by Bcl-2-associated athanogene (BAG) family proteins. Additionally, this mini-review emphasizes the regulatory role of BAG family proteins, which maintain mitochondrial homeostasis by regulating the PINK1/Parkin pathway. Elucidation of the regulatory mechanisms of mitophagy may foster the development of clinical therapeutic strategies for MDR tumors.
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Affiliation(s)
- Jufang Guo
- Department of Obstetrics and Gynecology, Jinniu District Maternal and Child Health Hospital, Chengdu, China
| | - Xuelian Du
- Department of Obstetrics and Gynecology, Jinniu District Maternal and Child Health Hospital, Chengdu, China
| | - Chaolin Li
- Department of Obstetrics and Gynecology, Jinniu District Maternal and Child Health Hospital, Chengdu, China.
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5
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Mariotto E, Corallo D, Pantile M, Giarin E, Pigazzi M, Basso G, Viola G, Aveic S. BAG1 down-regulation increases chemo-sensitivity of acute lymphoblastic leukaemia cells. J Cell Mol Med 2021; 25:9060-9065. [PMID: 34402163 PMCID: PMC8435410 DOI: 10.1111/jcmm.16822] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 07/12/2021] [Accepted: 07/16/2021] [Indexed: 12/13/2022] Open
Abstract
BCL2‐associated athanogene‐1 (BAG1) is a multi‐functional protein that is found deregulated in several solid cancers and in paediatric acute myeloid leukaemia. The investigation of BAG1 isoforms expression and intracellular localization in B‐cell acute lymphoblastic leukaemia (B‐ALL) patient‐derived specimens revealed that BAG1 levels decrease during disease remission, compared to diagnosis, but drastically increase at relapse. In particular, at diagnosis both BAG1‐L and BAG1‐M isoforms are mainly nuclear, while during remission the localization pattern changes, having BAG1‐M almost exclusively in the cytosol indicating its potential cytoprotective role in B‐ALL. In addition, knockdown of BAG1/BAG3 induces cell apoptosis and G1‐phase cell cycle arrest and, more intriguingly, shapes cell response to chemotherapy. BAG1‐depleted cells show an increased sensitivity to the common chemotherapeutic agents, dexamethasone or daunorubicin, and to the BCL2 inhibitor ABT‐737. Moreover, the BAG1 inhibitor Thio‐2 induces a cytotoxic effect on RS4;11 cells both in vitro and in a zebrafish xenograft model and strongly synergizes with pan‐BCL inhibitors. Collectively, these data sustain BAG1 deregulation as a critical event in assuring survival advantage to B‐ALL cells.
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Affiliation(s)
- Elena Mariotto
- Department of Woman's and Child's Health, Haematology-Oncology Clinic and Lab, University of Padova, Padova, Italy
| | - Diana Corallo
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Marcella Pantile
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Emanuela Giarin
- Department of Woman's and Child's Health, Haematology-Oncology Clinic and Lab, University of Padova, Padova, Italy
| | - Martina Pigazzi
- Department of Woman's and Child's Health, Haematology-Oncology Clinic and Lab, University of Padova, Padova, Italy.,Pediatric hematology, oncology and hematopoietic cell&gene therapy, Fondazione Istituto di Ricerca Pediatrica - Città della Speranza, Padova, Italy
| | - Giuseppe Basso
- Department of Woman's and Child's Health, Haematology-Oncology Clinic and Lab, University of Padova, Padova, Italy
| | - Giampietro Viola
- Department of Woman's and Child's Health, Haematology-Oncology Clinic and Lab, University of Padova, Padova, Italy.,Pediatric hematology, oncology and hematopoietic cell&gene therapy, Fondazione Istituto di Ricerca Pediatrica - Città della Speranza, Padova, Italy
| | - Sanja Aveic
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy.,Department of Dental Materials and Biomaterials Research, RWTH Aachen University Hospital, Aachen, Germany
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6
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De Marco M, Falco A, Iaccarino R, Raffone A, Mollo A, Guida M, Rosati A, Chetta M, Genovese G, De Caro F, Capunzo M, Turco MC, Uversky VN, Marzullo L. An emerging role for BAG3 in gynaecological malignancies. Br J Cancer 2021; 125:789-797. [PMID: 34099896 DOI: 10.1038/s41416-021-01446-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 04/23/2021] [Accepted: 05/17/2021] [Indexed: 12/15/2022] Open
Abstract
BAG3, a member of the BAG family of co-chaperones, is a multidomain protein with a role in several cellular processes, including the control of apoptosis, autophagy and cytoskeletal dynamics. The expression of bag3 is negligible in most cells but can be induced by stress stimuli or malignant transformation. In some tumours, BAG3 has been reported to promote cell survival and resistance to therapy. The expression of BAG3 has been documented in ovarian, endometrial and cervical cancers, and studies have revealed biochemical and functional connections of BAG3 with proteins involved in the survival, invasion and resistance to therapy of these malignancies. BAG3 expression has also been shown to correlate with the grade of dysplasia in squamous intraepithelial lesions of the uterine cervix. Some aspects of BAG3 activity, such as its biochemical and functional interaction with the human papillomavirus proteins, could help in our understanding of the mechanisms of oncogenesis induced by the virus. This review aims to highlight the potential value of BAG3 studies in the field of gynaecological tumours.
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Affiliation(s)
- Margot De Marco
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy.,BIOUNIVERSA s.r.l., R&D Division, Baronissi, SA, Italy
| | - Antonia Falco
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy.,BIOUNIVERSA s.r.l., R&D Division, Baronissi, SA, Italy
| | - Roberta Iaccarino
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | - Antonio Raffone
- Gynaecology and Obstetrics Unit, Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Antonio Mollo
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | - Maurizio Guida
- Gynaecology and Obstetrics Unit, Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Alessandra Rosati
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy.,BIOUNIVERSA s.r.l., R&D Division, Baronissi, SA, Italy
| | | | - Giovanni Genovese
- University Hospital "San Giovanni di Dio e Ruggi D'Aragona", Salerno, Italy
| | - Francesco De Caro
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | - Mario Capunzo
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | - Maria Caterina Turco
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy. .,BIOUNIVERSA s.r.l., R&D Division, Baronissi, SA, Italy.
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Laboratory of New Methods in Biology, Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center, Moscow region, Russia
| | - Liberato Marzullo
- Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy.,BIOUNIVERSA s.r.l., R&D Division, Baronissi, SA, Italy
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7
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De Marco M, Turco MC, Marzullo L. BAG3 in Tumor Resistance to Therapy. Trends Cancer 2020; 6:985-988. [PMID: 32718905 DOI: 10.1016/j.trecan.2020.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 01/12/2023]
Abstract
BAG3 is highly expressed across cancer types and its intracellular activity is critical for cancer cell survival. However, recent findings suggest that BAG3 can also modulate the tumor microenvironment to promote cancer progression and resistance to therapies, suggesting new ways to target this protein in cancer therapy.
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Affiliation(s)
- Margot De Marco
- Department of Medicine, Surgery and Dentistry, Schola Medica Salernitana, University of Salerno, Baronissi, Italy
| | - Maria Caterina Turco
- Department of Medicine, Surgery and Dentistry, Schola Medica Salernitana, University of Salerno, Baronissi, Italy.
| | - Liberato Marzullo
- Department of Medicine, Surgery and Dentistry, Schola Medica Salernitana, University of Salerno, Baronissi, Italy
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8
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Cristofani R, Crippa V, Cicardi ME, Tedesco B, Ferrari V, Chierichetti M, Casarotto E, Piccolella M, Messi E, Galbiati M, Rusmini P, Poletti A. A Crucial Role for the Protein Quality Control System in Motor Neuron Diseases. Front Aging Neurosci 2020; 12:191. [PMID: 32792938 PMCID: PMC7385251 DOI: 10.3389/fnagi.2020.00191] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/02/2020] [Indexed: 12/11/2022] Open
Abstract
Motor neuron diseases (MNDs) are fatal diseases characterized by loss of motor neurons in the brain cortex, in the bulbar region, and/or in the anterior horns of the spinal cord. While generally sporadic, inherited forms linked to mutant genes encoding altered RNA/protein products have also been described. Several different mechanisms have been found altered or dysfunctional in MNDs, like the protein quality control (PQC) system. In this review, we will discuss how the PQC system is affected in two MNDs—spinal and bulbar muscular atrophy (SBMA) and amyotrophic lateral sclerosis (ALS)—and how this affects the clearance of aberrantly folded proteins, which accumulate in motor neurons, inducing dysfunctions and their death. In addition, we will discuss how the PQC system can be targeted to restore proper cell function, enhancing the survival of affected cells in MNDs.
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Affiliation(s)
- Riccardo Cristofani
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Valeria Crippa
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Maria Elena Cicardi
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy.,Department of Neuroscience, Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Barbara Tedesco
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Veronica Ferrari
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Marta Chierichetti
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Elena Casarotto
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Margherita Piccolella
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Elio Messi
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Mariarita Galbiati
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Paola Rusmini
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy
| | - Angelo Poletti
- Laboratorio di Biologia Applicata, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2022, Università degli Studi di Milano, Milan, Italy.,Center of Excellence on Neurodegenerative Diseases (CEND), Università degli Studi di Milano, Milan, Italy
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9
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BAG3 deletion suppresses stem cell-like features of pancreatic ductal adenocarcinoma via translational suppression of ISG15. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:819-827. [DOI: 10.1016/j.bbamcr.2019.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 02/12/2019] [Accepted: 02/13/2019] [Indexed: 11/21/2022]
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Li C, An MX, Jiang JY, Yao HB, Li S, Yan J, Li XY, Wang HQ. BAG3 Suppresses Loading of Ago2 to IL6 mRNA in Pancreatic Ductal Adenocarcinoma. Front Oncol 2019; 9:225. [PMID: 31001483 PMCID: PMC6454118 DOI: 10.3389/fonc.2019.00225] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/13/2019] [Indexed: 01/16/2023] Open
Abstract
Pancreatic stellate cells (PSCs) are a subset of pancreatic cancer-associated fibroblasts, which play a critical role in pancreatic fibrosis, a characteristic feature of pancreatic cancer. The interplay between PSCs and pancreatic cancer cells is vital for promotion of tumor progression and metastasis. BAG3 is correlated with poor prognostics in patients with pancreatic ductal adenocarcinoma (PDAC), however, the exact mechanisms remain largely unknown. In this study, we demonstrated that BAG3 downregulation decreased IL6 release by PDACs, and IL6 reduction was, at least partially, responsible for suppression of PSCs activation by PDACs with BAG3 downmodulation. Importantly, BAG3 expression positively correlated with fibrosis in pancreatic cancer tissue. With regard to the underlying mechanism, we demonstrated that BAG3 knockdown facilitated recruitment of Agonaute 2 (Ago2) to IL6 mRNA, resulting in destabilization of IL6 mRNA. In addition, the current study demonstrated that phosphorylation at Serine (Ser) 387 site was required for recruitment of Ago2-containing miRISC to IL6 mRNA and BAG3 knockdown facilitated Ago2 loading to IL6 mRNA via increasing its phosphorylation at Ser 387. This study shed new light on the tumor-promoting role of BAG3 in PDAC tumors, suggesting BAG3 might represent an interesting therapeutic opportunity to PDAC patients.
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Affiliation(s)
- Chao Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China.,Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Ming-Xin An
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Jing-Yi Jiang
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Han-Bing Yao
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Si Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Jing Yan
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Xin-Yu Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Hua-Qin Wang
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China.,Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
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11
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Yuan T, Zhang F, Zhou X, Li Y, Zhang Y, Xu Y, Wang X. Inhibition of the PI3K/AKT signaling pathway sensitizes diffuse large B-cell lymphoma cells to treatment with proteasome inhibitors via suppression of BAG3. Oncol Lett 2019; 17:3719-3726. [PMID: 30881494 PMCID: PMC6403502 DOI: 10.3892/ol.2019.10029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 01/25/2019] [Indexed: 12/26/2022] Open
Abstract
Proteasome inhibitors represent a novel class of drugs that have clinical efficacy against hematological and solid cancer types, including acute myeloid leukaemia, myelodysplastic syndrome an non-small cell lung cancer. It has been demonstrated that the anti-apoptotic protein B-cell lymphoma-2-associated athanogene 3 (BAG3) is induced by proteasome inhibitors in various cancer cells and serves an important role in chemotherapy resistance. The phosphatidylinositol 3-kinase (PI3K)/RAC-α serine/threonine-protein kinase (AKT) pathway is constitutively activated in a number of lymphoid malignancy types, including diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma. In the present study, the aim was to elucidate the role of the PI3K/AKT signaling pathway in the induction of BAG3, following exposure to a proteasome inhibitor in DLBCL cell lines. Bortezomib and MG132 were used as proteasome inhibitors. Western blotting was used to evaluate the roles of proteasome inhibitors and the PI3K/AKT pathway in BAG3 induction in DLBCL cells (LY1 and LY8), and LY294002 was used to block the PI3K/AKT pathway. Cell viability was detected using a Cell Counting Kit-8 assay. Apoptosis of LY1 and LY8 cells was quantified by Annexin V/7-amino-actinomycin D flow cytometry. The BAG3 protein was markedly induced upon exposure to bortezomib and MG132 in a dose-dependent manner. The PI3K/AKT inhibitor LY294002 significantly suppressed the induction of BAG3 by proteasome inhibitors. Inhibition of the PI3K/AKT pathway decreased the proliferation and increased the apoptosis induced by proteasome inhibitors. The present results indicated that the PI3K/AKT pathway is associated with the activation of BAG3 expression in DLBCL cells, and is involved in the protective response against proteasome inhibition.
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Affiliation(s)
- Ting Yuan
- Department of Hematology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Feng Zhang
- Department of Hematology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Xiangxiang Zhou
- Department of Hematology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Ying Li
- Department of Hematology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Ya Zhang
- Department of Hematology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Yangyang Xu
- Department of Hematology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Xin Wang
- Department of Hematology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China.,Institute of Diagnostics, School of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
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12
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BAG3 regulates stability of IL-8 mRNA via interplay between HuR and miR-4312 in PDACs. Cell Death Dis 2018; 9:863. [PMID: 30154469 PMCID: PMC6113235 DOI: 10.1038/s41419-018-0874-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 06/20/2018] [Accepted: 06/22/2018] [Indexed: 12/13/2022]
Abstract
Bcl-2 associated athanogene 3 (BAG3) is highly expressed in pancreatic ductal adenocarcinoma (PDAC), and its high expression appears to be a poor prognostic factor for patients with PDAC. In this study, we show that BAG3 knockdown significantly decreases migration and invasion of PDACs via reduction of interleukine-8 (IL-8) production. BAG3 knockdown regulates IL-8 expression at the posttranscriptional levels via interplay between recruitment of RNA-binding protein HuR and miR-4312. HuR binds to the cis-elements located in the 3'-untranslational region (UTR) of the IL-8 transcript to stabilize it, whereas miR-4312-containing miRNA-induced silencing complex (miRISC) is recruited to the adjacent seed element to destabilize it. The binding of HuR prevents the recruitment of Argonaute (Ago2), overriding miR-4312-mediated translation inhibition of IL-8. BAG3 knockdown decreases cytoplasmic distribution of HuR via increasing its phosphorylation at Ser202, therefore compromising its recruitment while promoting recruitment of miR-4312 containing miRISC to IL-8 transcript. Furthermore, our data indicate that only phosphorylated Ago2 at Ser387 interacts with IL-8 transcript. BAG3 knockdown increases phosphorylation of Ago2 at Ser387, thereby further promoting loading of miR-4312 containing miRISC to IL-8 transcript. Taken together, we propose that BAG3 promotes invasion by stabilizing IL-8 transcript via HuR recruitment, and subsequently suppressing the loading of miR-4312 containing miRISC in PDACs. Our results reveal a novel pathway linking BAG3 expression to enhanced PDAC metastasis, thus making BAG3 a potential target for intervention in pancreatic cancer.
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13
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An MX, Li S, Yao HB, Li C, Wang JM, Sun J, Li XY, Meng XN, Wang HQ. BAG3 directly stabilizes Hexokinase 2 mRNA and promotes aerobic glycolysis in pancreatic cancer cells. J Cell Biol 2017; 216:4091-4105. [PMID: 29114069 PMCID: PMC5716268 DOI: 10.1083/jcb.201701064] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 05/15/2017] [Accepted: 09/18/2017] [Indexed: 12/23/2022] Open
Abstract
Aerobic glycolysis, a phenomenon known historically as the Warburg effect, is one of the hallmarks of cancer cells. In this study, we characterized the role of BAG3 in aerobic glycolysis of pancreatic ductal adenocarcinoma (PDAC) and its molecular mechanisms. Our data show that aberrant expression of BAG3 significantly contributes to the reprogramming of glucose metabolism in PDAC cells. Mechanistically, BAG3 increased Hexokinase 2 (HK2) expression, the first key enzyme involved in glycolysis, at the posttranscriptional level. BAG3 interacted with HK2 mRNA, and the degree of BAG3 expression altered recruitment of the RNA-binding proteins Roquin and IMP3 to the HK2 mRNA. BAG3 knockdown destabilized HK2 mRNA via promotion of Roquin recruitment, whereas BAG3 overexpression stabilized HK2 mRNA via promotion of IMP3 recruitment. Collectively, our results show that BAG3 promotes reprogramming of glucose metabolism via interaction with HK2 mRNA in PDAC cells, suggesting that BAG3 may be a potential target in the aerobic glycolysis pathway for developing novel anticancer agents.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Adenocarcinoma/genetics
- Adenocarcinoma/metabolism
- Adenocarcinoma/pathology
- Animals
- Apoptosis Regulatory Proteins/genetics
- Apoptosis Regulatory Proteins/metabolism
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- CRISPR-Associated Protein 9
- CRISPR-Cas Systems
- Cell Line, Tumor
- Cell Proliferation
- Clustered Regularly Interspaced Short Palindromic Repeats
- Endonucleases/genetics
- Endonucleases/metabolism
- Fibroblasts/cytology
- Fibroblasts/metabolism
- Gene Editing
- Gene Expression Regulation, Neoplastic
- Glucose/metabolism
- Glycolysis/genetics
- Hexokinase/genetics
- Hexokinase/metabolism
- Humans
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Neoplasm Transplantation
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Primary Cell Culture
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Ubiquitin-Protein Ligases/genetics
- Ubiquitin-Protein Ligases/metabolism
- RNA, Guide, CRISPR-Cas Systems
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Affiliation(s)
- Ming-Xin An
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
- Key Laboratory of Cell Biology, Ministry of Public Health, China Medical University, Shenyang, China
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Si Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Han-Bing Yao
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Chao Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Jia-Mei Wang
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Jia Sun
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Xin-Yu Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Xiao-Na Meng
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Hua-Qin Wang
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
- Key Laboratory of Cell Biology, Ministry of Public Health, China Medical University, Shenyang, China
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
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14
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Guerriero L, Palmieri G, De Marco M, Cossu A, Remondelli P, Capunzo M, Turco MC, Rosati A. The anti-apoptotic BAG3 protein is involved in BRAF inhibitor resistance in melanoma cells. Oncotarget 2017; 8:80393-80404. [PMID: 29113311 PMCID: PMC5655206 DOI: 10.18632/oncotarget.18902] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 06/13/2017] [Indexed: 01/10/2023] Open
Abstract
BAG3 protein, a member of BAG family of co-chaperones, has a pro-survival role in several tumour types. BAG3 anti-apoptotic properties rely on its characteristic to bind several intracellular partners, thereby modulating crucial events such as apoptosis, differentiation, cell motility, and autophagy. In human melanomas, BAG3 positivity is correlated with the aggressiveness of the tumour cells and can sustain IKK-γ levels, allowing a sustained activation of NF-κB. Furthermore, BAG3 is able to modulate BRAFV600E levels and activity in thyroid carcinomas. BRAFV600E is the most frequent mutation detected in malignant melanomas and is targeted by Vemurafenib, a specific inhibitor found to be effective in the treatment of advanced melanoma. However, patients with BRAF-mutated melanoma may result insensitive ab initio or, mostly, develop acquired resistance to the treatment with this molecule. Here we show that BAG3 down-modulation interferes with BRAF levels in melanoma cells and sensitizes them to Vemurafenib treatment. Furthermore, the down-modulation of BAG3 protein in an in vitro model of acquired resistance to Vemurafenib can induce sensitization to the BRAFV600E specific inhibition by interfering with BRAF pathway through reduction of ERK phosphorylation, but also on parallel survival pathways. Future studies on BAG3 molecular interactions with key proteins responsible of acquired BRAF inhibitor resistance may represent a promising field for novel multi-drugs treatment design.
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Affiliation(s)
| | - Giuseppe Palmieri
- Unit of Cancer Genetics, Institute of Biomolecular Chemistry (ICB), National Research Council (CNR), 07100 Sassari, Italy
| | | | - Antonio Cossu
- Unit of Pathology, Azienda Ospedaliero Universitaria (AOU), University di Sassari, 07100 Sassari, Italy
| | - Paolo Remondelli
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana” University of Salerno, 84084 Baronissi, Italy
| | - Mario Capunzo
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana” University of Salerno, 84084 Baronissi, Italy
| | - Maria Caterina Turco
- BIOUNIVERSA s.r.l., 84084 Baronissi, Italy
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana” University of Salerno, 84084 Baronissi, Italy
| | - Alessandra Rosati
- BIOUNIVERSA s.r.l., 84084 Baronissi, Italy
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana” University of Salerno, 84084 Baronissi, Italy
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15
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Role of BAG3 in cancer progression: A therapeutic opportunity. Semin Cell Dev Biol 2017; 78:85-92. [PMID: 28864347 DOI: 10.1016/j.semcdb.2017.08.049] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/26/2017] [Accepted: 08/28/2017] [Indexed: 02/06/2023]
Abstract
BAG3 is a multifunctional protein that can bind to heat shock proteins (Hsp) 70 through its BAG domain and to other partners through its WW domain, proline-rich (PXXP) repeat and IPV (Ile-Pro-Val) motifs. Its intracellular expression can be induced by stressful stimuli, while is constitutive in skeletal muscle, cardiac myocytes and several tumour types. BAG3 can modulate the levels, localisation or activity of its partner proteins, thereby regulating major cell pathways and functions, including apoptosis, autophagy, mechanotransduction, cytoskeleton organisation, motility. A secreted form of BAG3 has been identified in studies on pancreatic ductal adenocarcinoma (PDAC). Secreted BAG3 can bind to a specific receptor, IFITM2, expressed on macrophages, and induce the release of factors that sustain tumour growth and the metastatic process. BAG3 neutralisation therefore appears to constitute a novel potential strategy in the therapy of PDAC and, possibly, other tumours.
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16
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BAG3 promotes stem cell-like phenotype in breast cancer by upregulation of CXCR4 via interaction with its transcript. Cell Death Dis 2017; 8:e2933. [PMID: 28703799 PMCID: PMC5550869 DOI: 10.1038/cddis.2017.324] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/14/2017] [Accepted: 06/08/2017] [Indexed: 01/05/2023]
Abstract
BAG3 is an evolutionarily conserved co-chaperone expressed at high levels and has a prosurvival role in many tumor types. The current study reported that BAG3 was induced under specific floating culture conditions that enrich breast cancer stem cell (BCSC)-like cells in spheres. Ectopic BAG3 overexpression increased CD44+/CD24− CSC subpopulations, first-generation and second-generation mammosphere formation, indicating that BAG3 promotes CSC self-renewal and maintenance in breast cancer. We further demonstrated that mechanically, BAG3 upregulated CXCR4 expression at the post-transcriptional level. Further studies showed that BAG3 interacted with CXCR4 mRNA and promoted its expression via its coding and 3′-untranslational regions. BAG3 was also found to be positively correlated with CXCR4 expression and unfavorable prognosis in patients with breast cancer. Taken together, our data demonstrate that BAG3 promotes BCSC-like phenotype through CXCR4 via interaction with its transcript. Therefore, this study establishes BAG3 as a potential adverse prognostic factor and a therapeutic target of breast cancer.
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17
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Rusmini P, Cristofani R, Galbiati M, Cicardi ME, Meroni M, Ferrari V, Vezzoli G, Tedesco B, Messi E, Piccolella M, Carra S, Crippa V, Poletti A. The Role of the Heat Shock Protein B8 (HSPB8) in Motoneuron Diseases. Front Mol Neurosci 2017; 10:176. [PMID: 28680390 PMCID: PMC5478700 DOI: 10.3389/fnmol.2017.00176] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 05/18/2017] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and spinal and bulbar muscular atrophy (SBMA) are two motoneuron diseases (MNDs) characterized by aberrant protein behavior in affected cells. In familial ALS (fALS) and in SBMA specific gene mutations lead to the production of neurotoxic proteins or peptides prone to misfold, which then accumulate in form of aggregates. Notably, some of these proteins accumulate into aggregates also in sporadic ALS (sALS) even if not mutated. To prevent proteotoxic stresses detrimental to cells, misfolded and/or aggregated proteins must be rapidly removed by the protein quality control (PQC) system. The small heat shock protein B8 (HSPB8) is a chaperone induced by harmful events, like proteasome inhibition. HSPB8 is expressed both in motoneuron and muscle cells, which are both targets of misfolded protein toxicity in MNDs. In ALS mice models, in presence of the mutant proteins, HSPB8 is upregulated both in spinal cord and muscle. HSPB8 interacts with the HSP70 co-chaperone BAG3 and enhances the degradation of misfolded proteins linked to sALS, or causative of fALS and of SBMA. HSPB8 acts by facilitating autophagy, thereby preventing misfolded protein accumulation in affected cells. BAG3 and BAG1 compete for HSP70-bound clients and target them for disposal to the autophagy or proteasome, respectively. Enhancing the selective targeting of misfolded proteins by HSPB8-BAG3-HSP70 to autophagy may also decrease their delivery to the proteasome by the BAG1-HSP70 complex, thereby limiting possible proteasome overwhelming. Thus, approaches aimed at potentiating HSPB8-BAG3 may contribute to the maintenance of proteostasis and may delay MNDs progression.
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Affiliation(s)
- Paola Rusmini
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Riccardo Cristofani
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Mariarita Galbiati
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Maria E Cicardi
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Marco Meroni
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Veronica Ferrari
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Giulia Vezzoli
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Barbara Tedesco
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Elio Messi
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Margherita Piccolella
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy
| | - Serena Carra
- Dipartimento di Scienze Biomediche, Metaboliche e Neuroscienze, Università di Modena e Reggio EmiliaModena, Italy
| | - Valeria Crippa
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy.,C. Mondino National Neurological InstitutePavia, Italy
| | - Angelo Poletti
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di MilanoMilano, Italy.,Centro Interuniversitario sulle Malattie Neurodegenerative, Università degli Studi di Firenze, Roma Tor VergataMilano, Italy
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18
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Yan J, Liu C, Jiang JY, Liu H, Li C, Li XY, Yuan Y, Zong ZH, Wang HQ. BAG3 promotes proliferation of ovarian cancer cells via post-transcriptional regulation of Skp2 expression. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017. [PMID: 28624440 DOI: 10.1016/j.bbamcr.2017.06.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Bcl-2 associated athanogene 3 (BAG3) contains a modular structure, through which BAG3 interacts with a wide range of proteins, thereby affording its capacity to regulate multifaceted biological processes. BAG3 is often highly expressed and functions as a pro-survival factor in many cancers. However, the oncogenic potential of BAG3 remains not fully understood. The cell cycle regulator, S-phase kinase associated protein 2 (Skp2) is increased in various cancers and plays an important role in tumorigenesis. The current study demonstrated that BAG3 promoted proliferation of ovarian cancer cells via upregulation of Skp2. BAG3 stabilized Skp2 mRNA via its 3'-untranslated region (UTR). The current study demonstrated that BAG3 interacted with Skp2 mRNA. In addition, miR-21-5p suppressed Skp2 expression, which was compromised by forced BAG3 expression. These results indicated that at least some oncogenic functions of BAG3 were mediated through posttranscriptional regulation of Skp2 via antagonizing suppressive action of miR-21-5p in ovarian cancer cells.
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Affiliation(s)
- Jing Yan
- Department of Biochemistry & Molecular Biology, China Medical University, Shenyang 110026, China; Key Laboratory of Cell Biology, Ministry of Public Health, China Medical University, Shenyang 110026, China; Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110026, China
| | - Chuan Liu
- Department of Gynecology & Obstetrics, Sheng Jing Hospital, China Medical University, Shenyang 110005, China
| | - Jing-Yi Jiang
- Department of Biochemistry & Molecular Biology, China Medical University, Shenyang 110026, China
| | - Hans Liu
- Division of Geriatric Medicine and Gerontology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Chao Li
- Department of Biochemistry & Molecular Biology, China Medical University, Shenyang 110026, China
| | - Xin-Yu Li
- Department of Biochemistry & Molecular Biology, China Medical University, Shenyang 110026, China
| | - Ye Yuan
- Department of Biochemistry & Molecular Biology, China Medical University, Shenyang 110026, China
| | - Zhi-Hong Zong
- Department of Biochemistry & Molecular Biology, China Medical University, Shenyang 110026, China
| | - Hua-Qin Wang
- Department of Biochemistry & Molecular Biology, China Medical University, Shenyang 110026, China; Key Laboratory of Cell Biology, Ministry of Public Health, China Medical University, Shenyang 110026, China; Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110026, China.
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19
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Kong DH, Li S, Du ZX, Liu C, Liu BQ, Li C, Zong ZH, Wang HQ. BAG3 elevation inhibits cell proliferation via direct interaction with G6PD in hepatocellular carcinomas. Oncotarget 2016; 7:700-11. [PMID: 26621836 PMCID: PMC4808027 DOI: 10.18632/oncotarget.6396] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 11/14/2015] [Indexed: 01/15/2023] Open
Abstract
Bcl-2 associated athanogene 3 (BAG3) contains multiple protein-binding motifs to mediate potential interactions with chaperons and/or other proteins, which is possibly ascribed to the multifaceted functions assigned to BAG3. The current study demonstrated that BAG3 directly interacted with glucose 6 phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway (PPP). BAG3 suppressed the PPP flux, de novo DNA synthesis and cell growth in hepatocellular carcinomas (HCCs). The growth defect of HCCs with forced BAG3 expression can be rescued by enforced G6PD expression. However, BAG3 elevation did not cause a reduction in cellular NADPH concentrations, another main product of G6PD. In addition, supplement of nucleosides alone was sufficient to recover the growth defect mediated by BAG3 elevation. Collectively, the current study established a tumor suppressor-like function of BAG3 via direct interaction with G6PD in HCCs at the cellular level.
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Affiliation(s)
- De-Hui Kong
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China.,Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Si Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Zhen-Xian Du
- Department of Endocrinology and Metabolism, The 1st Affiliated Hospital, China Medical University, Shenyang, China
| | - Chuan Liu
- Department of Gynecology and Obstetrics, Shengjing Hospital, China Medical University, Shenyang, China
| | - Bao-Qin Liu
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Chao Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Zhi-Hong Zong
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
| | - Hua-Qin Wang
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China.,Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
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20
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BARTSCH GEORG, JENNEWEIN LUKAS, HARTER PATRICKN, ANTONIETTI PATRICK, BLAHETA ROMANA, KVASNICKA HANSMICHAEL, KÖGEL DONAT, HAFERKAMP AXEL, MITTELBRONN MICHEL, MANI JENS. Autophagy-associated proteins BAG3 and p62 in testicular cancer. Oncol Rep 2015; 35:1629-35. [DOI: 10.3892/or.2015.4505] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/03/2015] [Indexed: 11/06/2022] Open
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21
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Sherman MY, Gabai VL. Hsp70 in cancer: back to the future. Oncogene 2015; 34:4153-61. [PMID: 25347739 PMCID: PMC4411196 DOI: 10.1038/onc.2014.349] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/08/2014] [Accepted: 09/22/2014] [Indexed: 12/24/2022]
Abstract
Mechanistic studies from cell culture and animal models have revealed critical roles for the heat shock protein Hsp70 in cancer initiation and progression. Surprisingly, many effects of Hsp70 on cancer have not been related to its chaperone activity, but rather to its role(s) in regulating cell signaling. A major factor that directs Hsp70 signaling activity appears to be the co-chaperone Bag3. Here, we review these recent breakthroughs, and how these discoveries drive drug development efforts.
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Affiliation(s)
- Michael Y. Sherman
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, 02118, Tel 617-638-5971, Fax 617-638-5339
| | - Vladimir L. Gabai
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, 02118, Tel 617-638-5971, Fax 617-638-5339
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22
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Li S, Zhang HY, Wang T, Meng X, Zong ZH, Kong DH, Wang HQ, Du ZX. BAG3 promoted starvation-induced apoptosis of thyroid cancer cells via attenuation of autophagy. J Clin Endocrinol Metab 2014; 99:E2298-307. [PMID: 25062457 DOI: 10.1210/jc.2014-1779] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
CONTEXT BAG3 plays a regulatory role in a number of cellular processes. Recent studies have attracted much attention on its role in activation of selective autophagy. In addition, we have very recently reported that BAG3 is implicated in a BECN1-independent autophagy, namely noncanonical autophagy. OBJECTIVE The current study aimed to investigate the potential involvement of BAG3 in canonical autophagy triggered by Earle's Balanced Salt Solution (EBSS) starvation. SETTING AND DESIGN Replacement of complete medium with EBSS was used to trigger canonical autophagy. BAG3 expression was measured using real-time RT-PCR and Western blot. Autophagy was monitored using LC3-II transition and p62/SQSTM1 accumulation by Western blot, as well as punctate distribution of LC3 by immunofluorescence staining. Cell growth and apoptotic cell death was investigated using real-time cell analyzer and flowcytometry, respectively. RESULTS BAG3 expression was potently reduced by EBSS starvation. Forced expression of BAG3 suppressed autophagy and promoted apoptotic cell death of thyroid cancer cells elicited by starvation. In addition, in the presence of autophagy inhibitor, the enhancing effect of BAG3 on apoptotic cell death was attenuated. CONCLUSIONS These results suggest that BAG3 promotes apoptotic cell death in starved thyroid cancer cells, at least in part by autophagy attenuation.
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Affiliation(s)
- Si Li
- Departments of Endocrinology and Metabolism (S.L., T.W., Z.-X.D.), Geriatrics (H.-Y.Z.), and Biochemistry and Molecular Biology (X.M., Z.-H.Z., D.-H.K., H.-Q.W.), the First Affiliated Hospital, China Medical University, Shenyang 110001, China
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23
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BAG3 regulates epithelial-mesenchymal transition and angiogenesis in human hepatocellular carcinoma. J Transl Med 2014; 94:252-61. [PMID: 24365746 DOI: 10.1038/labinvest.2013.151] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 11/10/2013] [Accepted: 11/11/2013] [Indexed: 01/05/2023] Open
Abstract
Bcl2-associated athanogene 3 (BAG3) protein is a co-chaperone of heat-shock protein (Hsp) 70 and may regulate major physiological and pathophysiological processes. However, few reports have examined the role of BAG3 in human hepatocellular carcinoma (HCC). In this study, we show that BAG3 regulates epithelial-mesenchymal transition (EMT) and angiogenesis in HCC. BAG3 was overexpressed in HCC tissues and cell lines. BAG3 knockdown resulted in reduction in migration and invasion of HCC cells, which was linked to reversion of EMT by increasing E-cadherin expression and decreasing N-cadherin, vimentin and slug expression, as well as suppressing matrix metalloproteinase 2 (MMP-2) expression. In a xenograft tumorigenicity model, BAG3 knockdown effectively inhibited tumor growth and metastasis through reduction in CD34 and VEGF expression and reversal of the EMT pathway. In conclusion, BAG3 is associated with the invasiveness and angiogenesis in HCC, and the BAG3 gene may be a novel therapeutic approach against HCC.
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24
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Knockdown of BAG3 induces epithelial-mesenchymal transition in thyroid cancer cells through ZEB1 activation. Cell Death Dis 2014; 5:e1092. [PMID: 24577090 PMCID: PMC3944249 DOI: 10.1038/cddis.2014.32] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 12/15/2013] [Accepted: 01/14/2014] [Indexed: 12/13/2022]
Abstract
The process by which epithelial features are lost in favor of a mesenchymal phenotype is referred to as epithelial–mesenchymal transition (EMT). Most carcinomas use this mechanism to evade into neighboring tissues. Reduction or a loss of E-cadherin expression is a well-established hallmark of EMT. As a potent suppressor of E-cadherin, transcription factor ZEB1 is one of the key inducers of EMT, whose expression promotes tumorigenesis and metastasis of carcinomas. Bcl-2-associated athanogene 3 (BAG3) affects multifaceted cellular functions, including proliferation, apoptosis, cell adhesion and invasion, viral infection, and autophagy. Recently, we have reported a novel role of BAG3 implicated in EMT, while the mechanisms are poorly elucidated. The current study demonstrated that knockdown of BAG3 induced EMT, and increased cell migratory and invasiveness in thyroid cancer cells via transcriptional activation of ZEB1. We also found that BAG3 knockdown led to nuclear accumulation of β-catenin, which was responsible for the transcriptional activation of ZEB1. These results indicate BAG3 as a regulator of ZEB1 expression in EMT and as a regulator of metastasis in thyroid cancer cells, providing potential targets to prevent and/or treat thyroid cancer cell invasion and metastasis.
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Lim JH, Youn DY, Yoo HJ, Yoon HH, Kim MY, Chung S, Kim YS, Chang YS, Park CW, Lee JH. Aggravation of diabetic nephropathy in BCL-2 interacting cell death suppressor (BIS)-haploinsufficient mice together with impaired induction of superoxide dismutase (SOD) activity. Diabetologia 2014; 57:214-23. [PMID: 24078136 DOI: 10.1007/s00125-013-3064-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 09/05/2013] [Indexed: 12/17/2022]
Abstract
AIMS/HYPOTHESIS B cell CLL/lymphoma 2 (BCL-2)-interacting cell death suppressor (BIS), known as an anti-stress and anti-apoptotic protein, has been reported to modulate susceptibility to oxidative stress. This study investigated the potential role of BIS as an antioxidant protein in diabetic nephropathy. METHODS Diabetes was induced in BIS-heterozygote (BIS-HT) mice via streptozotocin injections and the resulting phenotypes were compared with those of BIS-wild-type (BIS-WT) mice over the 20 weeks following diabetes induction. RESULTS Renal injuries, represented by increased plasma creatinine levels and increased albuminuria, were greater in diabetic BIS-HT mice than in diabetic BIS-WT mice, and were accompanied by a significant increase in reactive oxygen species (ROS) and oxidative stress markers. Moreover, renal pathological changes and the apoptotic process were accelerated in diabetic BIS-HT mice compared with diabetic BIS-WT mice with the same degree of hyperglycaemia; all were restored by 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol) treatment. The levels of NADPH oxidase and related proteins were not significantly higher in diabetic BIS-HT mice compared with diabetic BIS-WT mice. However, levels of superoxide dismutase (SOD)1 and SOD2 increased on the induction of diabetes in BIS-WT mice but not in BIS-HT mice, correlating with the total SOD activity. An in vitro study showed that knockdown of BIS production also resulted in impaired induction of SOD activity as well as SOD levels in HK-2 and NMS cells, concomitant with significant ROS accumulation. CONCLUSION/INTERPRETATION Our results suggest that the decreased antioxidant capacity of BIS aggravates diabetic nephropathy in diabetic BIS-HT mice, possibly as a result of the disruption in the regulation of SOD protein quality under oxidative stress.
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Kong DH, Zhang Q, Meng X, Zong ZH, Li C, Liu BQ, Guan Y, Wang HQ. BAG3 sensitizes cancer cells exposed to DNA damaging agents via direct interaction with GRP78. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3245-3253. [DOI: 10.1016/j.bbamcr.2013.09.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 09/18/2013] [Accepted: 09/19/2013] [Indexed: 12/17/2022]
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Li C, Li S, Kong DH, Meng X, Zong ZH, Liu BQ, Guan Y, Du ZX, Wang HQ. BAG3 is upregulated by c-Jun and stabilizes JunD. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3346-3354. [PMID: 24140207 DOI: 10.1016/j.bbamcr.2013.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/08/2013] [Accepted: 10/08/2013] [Indexed: 01/09/2023]
Abstract
BAG3 plays a regulatory role in a number of cellular processes, including cell proliferation, apoptosis, adhesion and migration, epithelial-mesenchymal transition (EMT), autophagy activation, and virus infection. The AP-1 transcription factors are implicated in a variety of important biological processes including cell differentiation, proliferation, apoptosis and oncogenesis. Recently, it has been reported that AP-1 protein c-Jun inhibits autophagy and enhances apoptotic cell death mediated by starvation. However, the molecular mechanisms remain unclear. For the first time, the current study demonstrated that serum starvation downregulated BAG3 at the transcriptional level via c-Jun. In addition, the current study reported that BAG3 stabilized JunD mRNA, which was, at least in part, responsible for the promotion of serum starvation mediated-growth inhibition by BAG3.
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Affiliation(s)
- Chao Li
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001, China; Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; Key Laboratory of Cell Biology, Ministry of Public Health, China Medical University, Shenyang 110001, China
| | - Si Li
- Department of Endocrinology and Metabolism, the 1st Affiliated Hospital, China Medical University, Shenyang 110001, China
| | - De-Hui Kong
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001, China
| | - Xin Meng
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001, China
| | - Zhi-Hong Zong
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001, China
| | - Bao-Qin Liu
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001, China
| | - Yifu Guan
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001, China
| | - Zhen-Xian Du
- Department of Endocrinology and Metabolism, the 1st Affiliated Hospital, China Medical University, Shenyang 110001, China
| | - Hua-Qin Wang
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001, China; Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; Key Laboratory of Cell Biology, Ministry of Public Health, China Medical University, Shenyang 110001, China.
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Grant GD, Brooks L, Zhang X, Mahoney JM, Martyanov V, Wood TA, Sherlock G, Cheng C, Whitfield ML. Identification of cell cycle-regulated genes periodically expressed in U2OS cells and their regulation by FOXM1 and E2F transcription factors. Mol Biol Cell 2013; 24:3634-50. [PMID: 24109597 PMCID: PMC3842991 DOI: 10.1091/mbc.e13-05-0264] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Characterization of the cell cycle–regulated transcripts in U2OS cells yielded 1871 unique genes. FOXM1 targets were identified via ChIP-seq, and novel targets in G2/M and S phases were verified using a real-time luciferase assay. ChIP-seq data were used to map cell cycle transcriptional regulators of cell cycle–regulated gene expression in U2OS cells. We identify the cell cycle–regulated mRNA transcripts genome-wide in the osteosarcoma-derived U2OS cell line. This results in 2140 transcripts mapping to 1871 unique cell cycle–regulated genes that show periodic oscillations across multiple synchronous cell cycles. We identify genomic loci bound by the G2/M transcription factor FOXM1 by chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) and associate these with cell cycle–regulated genes. FOXM1 is bound to cell cycle–regulated genes with peak expression in both S phase and G2/M phases. We show that ChIP-seq genomic loci are responsive to FOXM1 using a real-time luciferase assay in live cells, showing that FOXM1 strongly activates promoters of G2/M phase genes and weakly activates those induced in S phase. Analysis of ChIP-seq data from a panel of cell cycle transcription factors (E2F1, E2F4, E2F6, and GABPA) from the Encyclopedia of DNA Elements and ChIP-seq data for the DREAM complex finds that a set of core cell cycle genes regulated in both U2OS and HeLa cells are bound by multiple cell cycle transcription factors. These data identify the cell cycle–regulated genes in a second cancer-derived cell line and provide a comprehensive picture of the transcriptional regulatory systems controlling periodic gene expression in the human cell division cycle.
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Affiliation(s)
- Gavin D Grant
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH 03755 Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
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Overexpressed BAG3 is a potential therapeutic target in chronic lymphocytic leukemia. Ann Hematol 2013; 93:425-35. [DOI: 10.1007/s00277-013-1883-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Accepted: 08/14/2013] [Indexed: 01/20/2023]
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Ulbricht A, Arndt V, Höhfeld J. Chaperone-assisted proteostasis is essential for mechanotransduction in mammalian cells. Commun Integr Biol 2013; 6:e24925. [PMID: 23986815 PMCID: PMC3737759 DOI: 10.4161/cib.24925] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/03/2013] [Accepted: 05/03/2013] [Indexed: 12/28/2022] Open
Abstract
Maintaining the dynamic proteome of a living cell in the face of an ever-changing environment depends on a fine-tuned balance of protein synthesis and protein degradation. Molecular chaperones exert key functions during protein homeostasis (proteostasis). They associate with nonnative client proteins following synthesis or damage and facilitate client sorting and folding. When client proteins are terminally misfolded, chaperones cooperate with protein degradation systems to dispose of such clients. This dual proteostasis activity of chaperones is essential for maintaining cell function under normal growth conditions and becomes even more important under stress conditions such as heat and oxidative stress. The recent identification of chaperone-assisted selective autophagy (CASA) as a tension-induced autophagy pathway highlights the critical role of molecular chaperones in mechanically strained cells and tissues. The CASA complex, assembled by the cochaperone BAG3, coordinates protein degradation and protein synthesis in response to mechanical force. Here we describe the composition and function of this chaperone complex in mammals and discuss its relevance for tissue homeostasis and the regulation of cell adhesion, migration and proliferation. We provide a unifying concept for the function of BAG3, which integrates its involvement in muscle maintenance, tumor formation and virus infection.
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Affiliation(s)
- Anna Ulbricht
- Institute for Cell Biology; University of Bonn; Bonn, Germany
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BAG3 induction is required to mitigate proteotoxicity via selective autophagy following inhibition of constitutive protein degradation pathways. Oncogene 2013; 33:1713-24. [PMID: 23644654 DOI: 10.1038/onc.2013.110] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 01/21/2013] [Accepted: 02/07/2013] [Indexed: 01/02/2023]
Abstract
Simultaneous inhibition of the two major constitutive protein quality control (PQC) pathways, that is, the ubiquitin-proteasome system (UPS) and the aggresome-autophagy system, has been suggested as a promising strategy to trigger cell death in cancer cells. However, we observed that one third of rhabdomyosarcoma (RMS) cells survives parallel inhibition of the UPS by Bortezomib and the aggresome-autophagy pathway by the cytoplasmic histone deacetylase 6 inhibitor ST80, and is able to regrow upon drug removal, thus pointing to the induction of compensatory pathways. Here, we identify Bcl-2-associated athanogene 3 (BAG3) as a critical mediator of inducible resistance in surviving cells after concomitant blockage of constitutive PQC pathways by mitigating ST80/Bortezomib-triggered proteotoxicity via selective autophagy. ST80/Bortezomib cotreatment upregulates BAG3 mRNA and protein levels in surviving cells in addition to triggering the accumulation of insoluble protein aggregates. Intriguingly, knockdown of BAG3 by RNA interference severely impairs clearance of protein aggregates, significantly increases cell death and reduces long-term survival and clonogenic growth during recovery after ST80/Bortezomib cotreatment. Similarly, inhibition of autophagy by inducible autophagy-related protein 7 knockdown prevents removal of protein aggregates and cell regrowth during recovery after ST80/Bortezomib cotreatment. Also, the inhibition of lysosomal degradation using the V-ATPase pump inhibitor Bafilomycin A1 enhances accumulation of protein aggregates, and completely abolishes regrowth after Bortezomib/ST80-induced proteotoxic stress. By identifying BAG3 as a key mediator of inducible resistance by mitigating proteotoxicity via selective autophagy after inhibition of constitutive PQC systems, our study provides new insights into the regulation of PQC pathways in cancer cells and identifies new targets for therapeutic intervention.
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Liu BQ, Du ZX, Zong ZH, Li C, Li N, Zhang Q, Kong DH, Wang HQ. BAG3-dependent noncanonical autophagy induced by proteasome inhibition in HepG2 cells. Autophagy 2013; 9:905-16. [PMID: 23575457 DOI: 10.4161/auto.24292] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Emerging lines of evidence have shown that blockade of ubiquitin-proteasome system (UPS) activates autophagy. The molecular players that regulate the relationship between them remain to be elucidated. Bcl-2 associated athanogene 3 (BAG3) is a member of the BAG co-chaperone family that regulates the ATPase activity of heat shock protein 70 (HSP70) chaperone family. Studies on BAG3 have demonstrated that it plays multiple roles in physiological and pathological processes, including antiapoptotic activity, signal transduction, regulatory role in virus infection, cell adhesion and migration. Recent studies have attracted much attention on its role in initiation of autophagy. The current study, for the first time, demonstrates that proteasome inhibitors elicit noncanonical autophagy, which was not suppressed by inhibitors of class III phosphatidylinositol 3-kinase (PtdIns3K) or shRNA against Beclin 1 (BECN1). In addition, we demonstrate that BAG3 is ascribed to activation of autophagy elicited by proteasome inhibitors and MAPK8/9/10 (also known as JNK1/2/3 respectively) activation is also implicated via upregulation of BAG3. Moreover, we found that noncanonical autophagy mediated by BAG3 suppresses responsiveness of HepG2 cells to proteasome inhibitors.
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Affiliation(s)
- Bao-Qin Liu
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, China
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PKCδ-mediated phosphorylation of BAG3 at Ser187 site induces epithelial−mesenchymal transition and enhances invasiveness in thyroid cancer FRO cells. Oncogene 2012; 32:4539-48. [DOI: 10.1038/onc.2012.466] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 07/27/2012] [Accepted: 08/19/2012] [Indexed: 11/08/2022]
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Rosati A, Bersani S, Tavano F, Dalla Pozza E, De Marco M, Palmieri M, De Laurenzi V, Franco R, Scognamiglio G, Palaia R, Fontana A, di Sebastiano P, Donadelli M, Dando I, Medema JP, Dijk F, Welling L, di Mola FF, Pezzilli R, Turco MC, Scarpa A. Expression of the antiapoptotic protein BAG3 is a feature of pancreatic adenocarcinoma and its overexpression is associated with poorer survival. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:1524-9. [PMID: 22944597 DOI: 10.1016/j.ajpath.2012.07.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 06/05/2012] [Accepted: 07/06/2012] [Indexed: 10/27/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is one of the most deadly cancers, being the fourth leading cause of cancer-related deaths. Long-term survival reaching 15% is achieved in less than 5% of patients who undergo surgery, and median survival is only 6 months in those with inoperable lesions. A deeper understanding of PDAC biologic characteristics as well as novel prognostic markers are therefore required to improve outcomes. Herein we report that BAG3, a protein with recognized anti-apoptotic activity, was expressed in 346 PDACs analyzed, but was not expressed in the surrounding nonneoplastic tissue. In a cohort of 66 patients who underwent radical resection (R0), survival was significantly shorter in patients with high BAG3 expression (median, 12 months) than in those with low BAG3 expression (median, 23 months) (P = 0.001). Furthermore, we report that BAG3 expression in PDAC-derived cell lines protects from apoptosis and confers resistance to gemcitabine, offering a partial explanation for the survival data. Our results indicate that BAG3 has a relevant role in PDAC biology, and suggest that BAG3 expression level might be a potential marker for prediction of patient outcome.
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Affiliation(s)
- Alessandra Rosati
- Department of Pharmaceutical and Biomedical Sciences, University of Salerno, Fisciano, Italy
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Role of BAG3 protein in leukemia cell survival and response to therapy. Biochim Biophys Acta Rev Cancer 2012; 1826:365-9. [PMID: 22710027 DOI: 10.1016/j.bbcan.2012.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 06/05/2012] [Accepted: 06/08/2012] [Indexed: 01/19/2023]
Abstract
The ability of BAG3, a member of the BAG family of heat shock protein (Hsp) 70 - cochaperones, to sustain the survival of human primary B-CLL and ALL cells was recognized about nine years ago. Since then, the anti-apoptotic activity of BAG3 has been confirmed in other tumor types, where it has been shown to regulate the intracellular concentration and localization of apoptosis-regulating factors, including NF-κB-activating (IKKγ) and Bcl2-family (Bax) proteins. Furthermore, growing evidences support its role in lymphoid and myeloid leukemia response to therapy. Moreover in the last years, the contribution of BAG3 to autophagy, a process known to be involved in the pathogenesis and response to therapy of leukemia cells, has been disclosed, opening a new avenue for the interpretation of the role of this protein in leukemias' biology.
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Basile A, Zeppa R, Pasquino N, Arra C, Ammirante M, Festa M, Barbieri A, Giudice A, Pascale M, Turco MC, Rosati A. Exposure to 50 Hz electromagnetic field raises the levels of the anti-apoptotic protein BAG3 in melanoma cells. J Cell Physiol 2011; 226:2901-7. [DOI: 10.1002/jcp.22641] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Youn DY, Yoon JS, Kim YK, Yeum CE, Lee SB, Youn HJ, Tsujimoto Y, Lee JH. Deletion of the bis gene results in a marked increase in the production of corticosterone that is associated with thymic atrophy in mice. Am J Physiol Endocrinol Metab 2011; 301:E223-31. [PMID: 21540452 DOI: 10.1152/ajpendo.00604.2010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Bis (Bag3) is known to be involved in cell survival, migration, the regulating of chaperones, and protein quality control. We reported recently on the production of bis gene-deleted mice, which show early lethality within 3 wk after birth with a phenotype showing severe malnutrition and shrinkage of the thymus. In this report, we provide evidence to show that an intrinsic problem of adrenal gland is the the primary cause for the severe atrophy of the thymus in bis(-/-) mice. The bis(-/-) mice show significantly higher levels of corticosterone, but CRH and ACTH levels were considerably lower than those of wild littermates. The transcription of steroidogenic enzymes was increased in the adrenal glands of bis(-/-) mice, accompanied by an increase in the thickness of the zona reticularis. An analysis of thymus tissue from bis(-/-) mice revealed that the severe atrophy of the thymus is due to the specific loss of immature double-positive (CD4(+)CD8(+)) cortical thymocytes by apoptosis, as evidenced by immunohistochemical examination and flow cytometric analysis, which were restored by injection of an inhibitor of glucocorticoid synthesis. In vitro cultures of thymocytes with increasing doses of dexamethasone exhibited a similar degree of apoptosis between wild and bis(-/-) thymocytes. The corticosterone levels from fasted wild littermates were one-half those of bis(-/-) mice, although serum glucose levels were similar. Thus, the deletion of the bis gene resulted in the intrinsic defect in the adrenal gland, leading to a marked increase in glucocorticoid levels, probably upon starvation stress, which accounts for the massive apoptosis of the thymus.
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Affiliation(s)
- Dong-Ye Youn
- Department of Biochemistry, College of Medicine, The Catholic University of Korea, Seoul, South Korea
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BAG3 protein is overexpressed in human glioblastoma and is a potential target for therapy. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:2504-12. [PMID: 21561597 DOI: 10.1016/j.ajpath.2011.02.002] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 01/30/2011] [Accepted: 02/07/2011] [Indexed: 12/15/2022]
Abstract
Glioblastoma multiforme, which represents 80% of malignant gliomas, is characterized by aggressiveness and high recurrence rates. Despite therapeutic advances, patients with glioblastoma multiforme show a poor survival, and identification of novel markers and molecular targets for therapy is needed. A role for BAG3, a member of the BAG family of HSC/HSP70 co-chaperones, in promoting tumor cell growth in vivo has recently been described. We analyzed BAG3 levels by IHC in specimens from patients affected by brain tumors and we found that BAG3, although negative in normal brain tissues, was highly expressed in astrocytic tumors and increasingly expressed in more aggressive types of cancer; it was particularly high in glioblastomas. Down-regulating BAG3 both in vitro and in vivo in a rat glioblastoma model resulted in increased sensitivity to apoptosis, suggesting that BAG3 is a potential target for novel therapies. Finally, we determined that the underlying molecular mechanism requires the formation of a complex of BAG3, HSP70, and BAX that prevents BAX translocation to mitochondria, thus protecting tumor cells from apoptosis. Our data identify BAG3 as a potential marker of glial brain tumor sensitivity to therapy and thus also an attractive candidate for new molecular therapies.
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Abstract
Bcl2-associated athanogene 3 (BAG3) protein is a member of BAG family of co-chaperones that interacts with the ATPase domain of the heat shock protein (Hsp) 70 through BAG domain (110–124 amino acids). BAG3 is the only member of the family to be induced by stressful stimuli, mainly through the activity of heat shock factor 1 on bag3 gene promoter. In addition to the BAG domain, BAG3 contains also a WW domain and a proline-rich (PXXP) repeat, that mediate binding to partners different from Hsp70. These multifaceted interactions underlie BAG3 ability to modulate major biological processes, that is, apoptosis, development, cytoskeleton organization and autophagy, thereby mediating cell adaptive responses to stressful stimuli. In normal cells, BAG3 is constitutively present in a very few cell types, including cardiomyocytes and skeletal muscle cells, in which the protein appears to contribute to cell resistance to mechanical stress. A growing body of evidence indicate that BAG3 is instead expressed in several tumor types. In different tumor contexts, BAG3 protein was reported to sustain cell survival, resistance to therapy, and/or motility and metastatization. In some tumor types, down-modulation of BAG3 levels was shown, as a proof-of-principle, to inhibit neoplastic cell growth in animal models. This review attempts to outline the emerging mechanisms that can underlie some of the biological activities of the protein, focusing on implications in tumor progression.
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Lee HC, Cherk SW, Chan SK, Wong S, Tong TW, Ho WS, Chan AY, Lee KC, Mak CM. BAG3-related myofibrillar myopathy in a Chinese family. Clin Genet 2011; 81:394-8. [PMID: 21361913 DOI: 10.1111/j.1399-0004.2011.01659.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In contrast to the usual slow disease progression in myofibrillar myopathies, patients with Bag3opathy often have a rapidly progressive and more severe phenotype with a worse prognosis. We describe a Chinese patient, born to non-consanguineous parents, who first presented at age 6 with clumsy walking and difficult climbing staircase. With a history of restrictive lung disease previously diagnosed as asthma, she progressed rapidly with proximal myopathy, rigid spine and bilateral tightening of the Achilles tendons requiring surgical elongation. Hypertrophic cardiomyopathy with restrictive physiology was shown by echocardiogram. Moreover, prolonged QT interval was also noted in the patient. Family history was unremarkable yet her father was incidentally found to have prolonged QT interval. Mutation analysis with genomic DNA of the proband showed heterozygous de novo known mutation c.626C>T (p.Pro209Leu) and a germline variation c.772C>T (p.Arg258Trp) in BAG3. Her father was found to be a carrier of c.772C>T. Muscle biopsy findings were suggestive of myofibrillar myopathy on light microscopy and ultrastructural studies. To our knowledge, this is the first Chinese case of Bag3opathy so far reported.
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Affiliation(s)
- H C Lee
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China
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Activation of heat shock factor 1 plays a role in pyrrolidine dithiocarbamate-mediated expression of the co-chaperone BAG3. Int J Biochem Cell Biol 2010; 42:1856-63. [PMID: 20692357 DOI: 10.1016/j.biocel.2010.07.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 07/16/2010] [Accepted: 07/30/2010] [Indexed: 12/18/2022]
Abstract
Adaptive responses to physical and inflammatory stressors are mediated by transcription factors and molecular chaperones. The transcription factor heat shock factor 1 (HSF1) has been implicated in extending lifespan in part by increasing expression of heat shock response genes. Pyrrolidine dithiocarbamate (PDTC) is a small thiol compound that exerts in vivo and in vitro anti-inflammatory properties through mechanisms that remain unclear. Here we report that PDTC induced the release of monomeric HSF1 from the molecular chaperone heat shock protein 90 (Hsp90), with concomitant increase in HSF1 trimer formation, translocation to the nucleus, and binding to promoter of target genes in human HepG2 cells. siRNA-mediated silencing of HSF1 blocked BAG3 gene expression by PDTC. The protein levels of the co-chaperone BAG3 and its interaction partner Hsp72 were stimulated by PDTC in a dose-dependent fashion, peaking at 6h. Inhibition of Hsp90 function by geldanamycin derivatives and novobiocin elicited a pattern of HSF1 activation and BAG3 expression that was similar to PDTC. Chromatin immunoprecipitation studies showed that PDTC and the inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin enhanced the binding of HSF1 to the promoter of several target genes, including BAG3, HSPA1A, HSPA1B, FKBP4, STIP1 and UBB. Cell treatment with PDTC increased significantly the level of Hsp90α thiol oxidation, a posttranslational modification known to inhibit its chaperone function. These results unravel a previously unrecognized mechanism by which PDTC and related compounds could confer cellular protection against inflammation through HSF1-induced expression of heat shock response genes.
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Wang HQ, Meng X, Gao YY, Liu BQ, Niu XF, Zhang HY, Du ZX. Characterization of BAG3 cleavage during apoptosis of pancreatic cancer cells. J Cell Physiol 2010; 224:94-100. [PMID: 20232307 DOI: 10.1002/jcp.22097] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Caspases are a conserved family of cell death proteases that cleave intracellular substrates at Asp residues to modify their function and promote apoptosis. In this report, we identify BAG3 as a novel caspases substrate. Here, we show that one of these BAG proteins, BAG3, is cleaved during apoptosis. BAG3 cleavage is inhibited by several different caspase inhibitors. The analysis of BAG3 cleavage by recombinant caspase proteins shows that BAG3 is efficiently cleaved by caspase-3, to a smaller extent by caspases-1 and -8, and relatively inefficient by caspase-9. Cleavage of the BAG3 protein occurs in the C-terminal part of the protein majorly at Asp347 (KEVD347 downward arrow S) in vitro and in pancreatic cancer SW1990 and PANC-1 cells undergoing apoptosis. We also demonstrate that unlike cleavage of Bcl-2 and Bcl-XL, cleaved form of BAG3 does not result in pro-apoptotic fragments, however, cleavage of BAG3 lead to loss its per se anti-apoptotic property. This novel regulation of BAG3 may have important implications for its role in apoptosis.
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Affiliation(s)
- Hua-Qin Wang
- Department of Biochemistry & Molecular Biology, China Medical University, Shenyang, China.
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44
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Kwon KR, Ahn JY, Kim MS, Jung JY, Lee JH, Oh IH. Disruption of bis leads to the deterioration of the vascular niche for hematopoietic stem cells. Stem Cells 2010; 28:268-78. [PMID: 20024912 DOI: 10.1002/stem.285] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The stem cell niche plays an important role in the microenvironmental regulation of hematopoietic stem cells, but the integration of niche activity remains poorly understood. In this study, we show that a functional deficiency of Bis/BAG-3/CAIR-1, a protein related to apoptosis and the response to cellular stress, results in perturbation of the vascular stem cell niche, causing a series of hematopoietic derangements. Mice with a targeted disruption of bis (bis(-/-)) exhibited a loss of hematopoietic stem cells and defective B-cell development. However, this hematological defect of bis(-/-) mice was not reproduced when bis(-/-) bone marrow cells were transplanted into bis(+/+) recipients. Moreover, bis(+/+) bone marrow cells, when transplanted into bis(-/-) mice, reproduced the same defect as bis(-/-) cells, pointing to the microenvironmental origin of the phenotypes. Subsequent analysis of bis(-/-) mice bone marrow revealed a characteristic defect in the vascular stem cell niche that included the defective growth of stromal progenitor cells in colony forming unit-fibroblasts, the defect in sinusoidal endothelium, and the loss of stromal cells expressing CXCL-12 or IL-7 in the bone marrow. In contrast, no abnormalities were observed in the growth and hematopoietic supporting activities of osteoblasts from bis(-/-) mice bone marrows. Collectively, these results indicate that Bis functions to mediate cellular regulation of the stem cell niche on the vascular compartment and suggest that the vascular and osteoblastic compartments of the stem cell niche can be independently regulated during the in vivo orchestration of hematopoiesis.
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Affiliation(s)
- Kyung-Rim Kwon
- Catholic Cell Therapy Center & Department of Cellular Medicine, The Catholic University of Korea, Seoul, Korea
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IKK{gamma} protein is a target of BAG3 regulatory activity in human tumor growth. Proc Natl Acad Sci U S A 2010; 107:7497-502. [PMID: 20368414 DOI: 10.1073/pnas.0907696107] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BAG3, a member of the BAG family of heat shock protein (HSP) 70 cochaperones, is expressed in response to stressful stimuli in a number of normal cell types and constitutively in a variety of tumors, including pancreas carcinomas, lymphocytic and myeloblastic leukemias, and thyroid carcinomas. Down-regulation of BAG3 results in cell death, but the underlying molecular mechanisms are still elusive. Here, we investigated the molecular mechanism of BAG3-dependent survival in human osteosarcoma (SAOS-2) and melanoma (M14) cells. We show that bag3 overexpression in tumors promotes survival through the NF-kappaB pathway. Indeed, we demonstrate that BAG3 alters the interaction between HSP70 and IKKgamma, increasing availability of IKKgamma and protecting it from proteasome-dependent degradation; this, in turn, results in increased NF-kappaB activity and survival. These results identify bag3 as a potential target for anticancer therapies in those tumors in which this gene is constitutively expressed. As a proof of principle, we show that treatment of a mouse xenograft tumor model with bag3siRNA-adenovirus that down-regulates bag3 results in reduced tumor growth and increased animal survival.
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Choi JS, Lee JH, Shin YJ, Lee JY, Yun H, Chun MH, Lee MY. Transient expression of Bis protein in midline radial glia in developing rat brainstem and spinal cord. Cell Tissue Res 2009; 337:27-36. [DOI: 10.1007/s00441-009-0794-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 03/17/2009] [Indexed: 10/20/2022]
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Rosati A, Khalili K, Deshmane SL, Radhakrishnan S, Pascale M, Turco MC, Marzullo L. BAG3 protein regulates caspase-3 activation in HIV-1-infected human primary microglial cells. J Cell Physiol 2009; 218:264-7. [PMID: 18821563 PMCID: PMC4503248 DOI: 10.1002/jcp.21604] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BAG3, a member of the BAG co-chaperones family, is expressed in several cell types subjected to stressful conditions, such as exposure to high temperature, heavy metals, drugs. Furthermore, it is constitutively expressed in some tumors. Among the biological activities of the protein, there is apoptosis downmodulation; this appears to be exerted through BAG3 interaction with the heat shock protein (Hsp) 70, that influences cell apoptosis at several levels. We recently reported that BAG3 protein was detectable in the cytoplasm of reactive astrocytes in HIV-1-associated encephalopathy biopsies. Here we report that downmodulation of BAG3 protein levels allows caspase-3 activation by HIV-1 infection in human primary microglial cells. This is the first reported evidence of a role for BAG3 in the balance of death versus survival during viral infection.
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Affiliation(s)
- Alessandra Rosati
- Department of Pharmaceutical Sciences (DiFarma), University of Salerno, Salerno, Italy
| | - Kamel Khalili
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Satish L. Deshmane
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Sujatha Radhakrishnan
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Maria Pascale
- Department of Pharmaceutical Sciences (DiFarma), University of Salerno, Salerno, Italy
| | - M. Caterina Turco
- Department of Pharmaceutical Sciences (DiFarma), University of Salerno, Salerno, Italy
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Jacobs AT, Marnett LJ. HSF1-mediated BAG3 expression attenuates apoptosis in 4-hydroxynonenal-treated colon cancer cells via stabilization of anti-apoptotic Bcl-2 proteins. J Biol Chem 2009; 284:9176-83. [PMID: 19179333 DOI: 10.1074/jbc.m808656200] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
4-Hydroxynonenal (HNE) is a pro-apoptotic electrophile generated during the spontaneous decomposition of oxidized lipids. We have previously shown that HNE activates the transcription factor, heat shock factor 1 (HSF1), and promotes cytoprotective heat shock gene expression and that silencing HSF1 sensitizes the colon cancer cell line RKO to HNE-induced apoptosis. Here we report a reduction in the anti-apoptotic proteins Bcl-X(L), Mcl-1, and Bcl-2 in HSF1-silenced RKO cells, and we examine the underlying mechanism. To investigate the regulation of the Bcl-2 family by HSF1, microarray analysis of gene expression was performed. We observed that the Hsp70 co-chaperone, BAG3 (Bcl-2-associated athanogene domain 3), is strongly induced by HNE in control but not in HSF1-silenced colon cancer cells. Silencing BAG3 expression with small interfering RNA caused a dramatic reduction in Bcl-X(L), Mcl-1, and Bcl-2 protein levels in colon cancer cells and increased apoptosis, similar to the effect of silencing HSF1. Also, immunoprecipitation experiments indicate specific interactions between BAG3, Hsp70, and the Bcl-2 family member, Bcl-X(L). Overall, our data reveal that BAG3 is HSF1-inducible and has a unique role facilitating cancer cell survival during pro-apoptotic stress by stabilizing the level of Bcl-2 family proteins.
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Affiliation(s)
- Aaron T Jacobs
- Department of Biochemistry, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, and Vanderbilt-Ingram Comprehensive Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA
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Du ZX, Zhang HY, Meng X, Gao YY, Zou RL, Liu BQ, Guan Y, Wang HQ. Proteasome inhibitor MG132 induces BAG3 expression through activation of heat shock factor 1. J Cell Physiol 2009; 218:631-7. [PMID: 19006120 DOI: 10.1002/jcp.21634] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BAG3 protein, a member of the BAG co-chaperones family, sustains cell survival in a variety of normal and neoplastic cell types, via its interaction with a variety of partners, such as the heat shock protein (HSP) 70, Bcl-2, Raf-1 and others. Expression of BAG3 is induced by some stressful stimuli, such as heat shock, heavy metal exposure. We have reported that proteasome inhibitors can also induce BAG3 expression at the transcriptional level and the induction of BAG3 compromises proteasome inhibitors-mediated apoptosis. However, the molecular mechanism of BAG3 upregulation has not been elucidated. In the current study, we provide evidence that heat shock transcription factor 1 (HSF1) is involved in BAG3 induction by proteasome inhibitor MG132. Using a series of varying lengths of 5'-flanking region of the BAG3 gene into luciferase reporter vectors, we found that MG132 stimulated the promoter activity via the -326/-233 and -825/-689 regions, which contains one putative heat shock-responsive element (HSE) for HSF1-binding, respectively. Site-directed deletion of the sites abrogated the enhanced reporter activity in response to MG132 treatment. Chromatin immunoprecipitation assay demonstrated that HSF1 directly bound to the MG132-responsive site on the BAG3 promoter. Activation of HSF1 occurred with MG132 along with BAG3 upregulation. Furthermore, knockdown HSF1 by small interfering RNA attenuated the BAG3 upregulation due to MG132.These results indicate that the proteasome inhibitor MG132 induces BAG3 expression through HSF1 activation.
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Affiliation(s)
- Zhen-Xian Du
- Department of Endocrinology & Metabolism, The 1st Affiliated Hospital, China Medical University, Shenyang, China
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BAG3 gene silencing sensitizes leukemic cells to Bortezomib-induced apoptosis. FEBS Lett 2008; 583:401-6. [PMID: 19111544 DOI: 10.1016/j.febslet.2008.12.032] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 11/29/2008] [Accepted: 12/11/2008] [Indexed: 12/18/2022]
Abstract
Proteasome inhibition has emerged as a powerful option for the treatment of a number of malignancies including leukemias. However, Bortezomib showed limited single-agent activity for patients with leukemia. Here, we report for the first time that Bortezomib up-regulated a novel antiapoptotic protein, BAG3, in human leukemic cells. BAG3 gene knockdown with shRNA greatly potentiated the generation of apoptosis by Bortezomib in leukemia cells. Furthermore, BAG3 silencing enhanced the antitumor activity of Bortezomib dramatically in a nude mouse model. Our results indicate that knocking down BAG3 gene is a promising new approach to enhance the therapeutic potency of Bortezomib in leukemia.
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