1
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Zheng M, Liu W, Zhang R, Jiang D, Shi Y, Wu Y, Ge F, Chen C. E3 ubiquitin ligase BCA2 promotes breast cancer stemness by up-regulation of SOX9 by LPS. Int J Biol Sci 2024; 20:2686-2697. [PMID: 38725852 PMCID: PMC11077363 DOI: 10.7150/ijbs.92338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 04/19/2024] [Indexed: 05/12/2024] Open
Abstract
Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer. Breast cancer stem cells (BCSCs) are believed to play a crucial role in the carcinogenesis, therapy resistance, and metastasis of TNBC. It is well known that inflammation promotes stemness. Several studies have identified breast cancer-associated gene 2 (BCA2) as a potential risk factor for breast cancer incidence and prognosis. However, whether and how BCA2 promotes BCSCs has not been elucidated. Here, we demonstrated that BCA2 specifically promotes lipopolysaccharide (LPS)-induced BCSCs through LPS induced SOX9 expression. BCA2 enhances the interaction between myeloid differentiation primary response protein 88 (MyD88) and Toll-like receptor 4 (TLR4) and inhibits the interaction of MyD88 with deubiquitinase OTUD4 in the LPS-mediated NF-κB signaling pathway. And SOX9, an NF-κB target gene, mediates BCA2's pro-stemness function in TNBC. Our findings provide new insights into the molecular mechanisms by which BCA2 promotes breast cancer and potential therapeutic targets for the treatment of breast cancer.
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Affiliation(s)
- Min Zheng
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China
- Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Wenjing Liu
- The Third Affiliated Hospital, Kunming Medical University, Kunming, 650118, China
| | - Rou Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China
| | - Dewei Jiang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China
- Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yujie Shi
- Department of Pathology, Henan Provincial People's Hospital, Zhengzhou University, Zhengzhou, China
| | - Yingying Wu
- The First Affiliated Hospital, Kunming Medical University, Kunming, 650032, China
| | - Fei Ge
- The First Affiliated Hospital, Kunming Medical University, Kunming, 650032, China
| | - Ceshi Chen
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China
- Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming, Yunnan, China
- The Third Affiliated Hospital, Kunming Medical University, Kunming, 650118, China
- Academy of Biomedical Engineering, Kunming Medical University, Kunming, 650500, China
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2
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Wang MX, Liuyu T, Zhang ZD. Multifaceted Roles of the E3 Ubiquitin Ligase RING Finger Protein 115 in Immunity and Diseases. Front Immunol 2022; 13:936579. [PMID: 35844553 PMCID: PMC9279554 DOI: 10.3389/fimmu.2022.936579] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/06/2022] [Indexed: 11/25/2022] Open
Abstract
Ubiquitination is a post-translational modification that plays essential roles in various physiological and pathological processes. Protein ubiquitination depends on E3 ubiquitin ligases that catalyze the conjugation of ubiquitin molecules on lysine residues of targeted substrates. RING finger protein 115 (RNF115), also known as breast cancer associated gene 2 (BCA2) and Rab7-interacting RING finger protein (Rabring7), has been identified as a highly expressed protein in breast cancer cells and tissues. Later, it has been demonstrated that RNF115 catalyzes ubiquitination of a series of proteins to modulate a number of signaling pathways, and thereby regulates viral infections, autoimmunity, cell proliferation and death and tumorigenesis. In this review, we introduce the identification, expression and activity regulation of RNF115, summarize the substrates and functions of RNF115 in different pathways, and discuss the roles of RNF115 as a biomarker or therapeutic target in diseases.
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Affiliation(s)
- Mei-Xia Wang
- The Executive Master of Business Administration (EMBA) Program, School of Management, Fudan University, Shanghai, China
| | - Tianzi Liuyu
- Department of Gastrointestinal Surgery, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Zhi-dong Zhang
- Department of Gastrointestinal Surgery, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan, China
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3
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Oh D, Chen Z, Biswas KH, Bai F, Ong HT, Sheetz MP, Groves JT. Competition for shared downstream signaling molecules establishes indirect negative feedback between EGFR and EphA2. Biophys J 2022; 121:1897-1908. [DOI: 10.1016/j.bpj.2022.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/21/2022] [Accepted: 04/12/2022] [Indexed: 11/02/2022] Open
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4
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Shi Y, Castro-Gonzalez S, Chen Y, Serra-Moreno R. Effects of the SUMO Ligase BCA2 on Metabolic Activity, Cell Proliferation, Cell Migration, Cell Cycle, and the Regulation of NF-κB and IRF1 in Different Breast Epithelial Cellular Contexts. Front Cell Dev Biol 2021; 9:711481. [PMID: 34589482 PMCID: PMC8473798 DOI: 10.3389/fcell.2021.711481] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/25/2021] [Indexed: 12/28/2022] Open
Abstract
Breast cancer-associated gene 2 (BCA2) is an E3 ubiquitin and SUMO ligase with antiviral properties against HIV. Specifically, BCA2 (i) enhances the restriction imposed by BST2/Tetherin, impeding viral release; (ii) promotes the ubiquitination and degradation of the HIV protein Gag, limiting virion production; (iii) down-regulates NF-κB, which is necessary for HIV RNA synthesis; and (iv) activates the innate transcription factor IRF1. Due to its antiviral properties, ectopic expression of BCA2 in infected cells represents a promising therapeutic approach against HIV infection. However, BCA2 up-regulation is often observed in breast tumors. To date, the studies about BCA2 and cancer development are controversial, stating both pro- and anti-oncogenic roles. Here, we investigated the impact of BCA2 on cellular metabolic activity, cell proliferation, cell migration, and cell cycle progression. In addition, we also examined the ability of BCA2 to regulate NF-κB and IRF1 in transformed and non-tumor breast epithelial environments. Despite the fact that BCA2 promotes the transition from G1 to S phase of the cell cycle, it did not increase cell proliferation, migration nor metabolic activity. As expected, BCA2 maintains its enzymatic function at inhibiting NF-κB in different breast cancer cell lines. However, the effect of BCA2 on IRF1 differs depending on the cellular context. Specifically, BCA2 activates IRF1 in ER+ breast cell lines while it inhibits this transcription factor in ER– breast cancer cells. We hypothesize that the distinct actions of BCA2 over IRF1 may explain, at least in part, the different proposed roles for BCA2 in these cancers.
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Affiliation(s)
- Yuhang Shi
- Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States
| | | | - Yuexuan Chen
- Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States
| | - Ruth Serra-Moreno
- Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States
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5
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Zhang R, Liu W, Sun J, Kong Y, Chen C. Roles of RNF126 and BCA2 E3 ubiquitin ligases in DNA damage repair signaling and targeted cancer therapy. Pharmacol Res 2020; 155:104748. [DOI: 10.1016/j.phrs.2020.104748] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 01/16/2023]
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6
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Wymant JM, Sayers EJ, Muir D, Jones AT. Strategic Trastuzumab Mediated Crosslinking Driving Concomitant HER2 and HER3 Endocytosis and Degradation in Breast Cancer. J Cancer 2020; 11:3288-3302. [PMID: 32231734 PMCID: PMC7097966 DOI: 10.7150/jca.32470] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/04/2020] [Indexed: 01/03/2023] Open
Abstract
Efficacious anticancer therapies for targeting plasma membrane receptors with antibody based therapeutics are often contingent on sufficient endocytic delivery of receptor and conjugate to lysosomes. This results in downregulation of receptor activity and, in the case of antibody-drug conjugates (ADCs), intracellular release of a drug payload. The oncogenic receptor HER2 is a priority therapeutic target in breast cancer. Known as an "endocytosis resistant" receptor, HER2 thwarts the receptor downregulating efficiency of the frontline treatment trastuzumab and reduces the potential of trastuzumab-based therapies such as trastuzumab-emtansine. We previously demonstrated that strategically inducing trastuzumab and HER2 crosslinking in breast cancer cells promoted endocytosis and lysosomal delivery of the HER2-trastuzumab complex, stimulating downregulation of the receptor. Here we reveal that HER3, but not EGFR, is also concomitantly downregulated with HER2 after crosslinking. This is accompanied by strong activation of MEK/ERK pathway that we show does not directly contribute to HER2/trastuzumab endocytosis. We show that crosslinking induced trastuzumab endocytosis occurs via clathrin-dependent and independent pathways and is an actin-dependent process. Detailed ultrastructural studies of the plasma membrane highlight crosslinking-specific remodelling of microvilli and induction of extensive ruffling. Investigations in a cell model of acquired trastuzumab resistance demonstrate, for the first time, that they are refractory to crosslinking induced HER2 endocytosis and downregulation. This implicates further arrest of HER2 internalisation in developing trastuzumab resistance. Overall our findings highlight the potential of receptor crosslinking as a therapeutic strategy for cancer while exposing the ability of cancer cells to develop resistance via endocytic mechanisms.
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Affiliation(s)
- Jennifer Mary Wymant
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB
| | - Edward John Sayers
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB
| | - Duncan Muir
- School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT
| | - Arwyn Tomos Jones
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB
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7
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Promchan K, Natarajan V. Leucine zipper transcription factor-like 1 binds adaptor protein complex-1 and 2 and participates in trafficking of transferrin receptor 1. PLoS One 2020; 15:e0226298. [PMID: 31895934 PMCID: PMC6939906 DOI: 10.1371/journal.pone.0226298] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 11/22/2019] [Indexed: 11/27/2022] Open
Abstract
LZTFL1 participates in immune synapse formation, ciliogenesis, and the localization of ciliary proteins, and knockout of LZTFL1 induces abnormal distribution of heterotetrameric adaptor protein complex-1 (AP-1) in the Lztfl1-knockout mouse photoreceptor cells, suggesting that LZTFL1 is involved in intracellular transport. Here, we demonstrate that in vitro LZTFL1 directly binds to AP-1 and AP-2 and coimmunoprecipitates AP-1 and AP-2 from cell lysates. DxxFxxLxxxR motif of LZTFL1 is essential for these bindings, suggesting LZTFL1 has roles in AP-1 and AP-2-mediated protein trafficking. Since AP-1 and AP-2 are known to be involved in transferrin receptor 1 (TfR1) trafficking, the effect of LZTFL1 on TfR1 recycling was analyzed. TfR1, AP-1 and LZTFL1 from cell lysates could be coimmunoprecipitated. However, pull-down results indicate there is no direct interaction between TfR1 and LZTFL1, suggesting that LZTFL1 interaction with TfR1 is indirect through AP-1. We report the colocalization of LZTFL1 and AP-1, AP-1 and TfR1 as well as LZTFL1 and TfR1 in the perinuclear region (PNR) and the cytoplasm, suggesting a potential complex between LZTFL1, AP-1 and TfR1. The results from the disruption of adaptin recruitment with brefeldin A treatment suggested ADP-ribosylation factor-dependent localization of LZFL1 and AP-1 in the PNR. Knockdown of AP-1 reduces the level of LZTFL1 in the PNR, suggesting that AP-1 plays a role in LZTFL1 trafficking. Knockout of LZTFL1 reduces the cell surface level and the rate of internalization of TfR1, leading to a decrease of transferrin uptake, efflux, and internalization. However, knockout of LZTFL1 did not affect the cell surface levels of epidermal growth factor receptor and cation-independent mannose 6-phosphate receptor, indicating that LZTFL1 specifically regulates the cell surface level of TfR1. These data support a novel role of LZTFL1 in regulating the cell surface TfR1 level by interacting with AP-1 and AP-2.
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Affiliation(s)
- Kanyarat Promchan
- Laboratory of Molecular Cell Biology, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, United States of America
| | - Ven Natarajan
- Laboratory of Molecular Cell Biology, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, United States of America
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8
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Guerra F, Bucci C. Role of the RAB7 Protein in Tumor Progression and Cisplatin Chemoresistance. Cancers (Basel) 2019; 11:cancers11081096. [PMID: 31374919 PMCID: PMC6721790 DOI: 10.3390/cancers11081096] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/23/2019] [Accepted: 07/30/2019] [Indexed: 12/19/2022] Open
Abstract
RAB7 is a small guanosine triphosphatase (GTPase) extensively studied as regulator of vesicular trafficking. Indeed, its role is fundamental in several steps of the late endocytic pathway, including endosome maturation, transport from early endosomes to late endosomes and lysosomes, clustering and fusion of late endosomes and lysosomes in the perinuclear region and lysosomal biogenesis. Besides endocytosis, RAB7 is important for a number of other cellular processes among which, autophagy, apoptosis, signaling, and cell migration. Given the importance of RAB7 in these cellular processes, the interest to study the role of RAB7 in cancer progression is widely grown. Here, we describe the current understanding of oncogenic and oncosuppressor functions of RAB7 analyzing cellular context and other environmental factors in which it elicits pro and/or antitumorigenic effects. We also discuss the role of RAB7 in cisplatin resistance associated with its ability to regulate the late endosomal pathway, lysosomal biogenesis and extracellular vesicle secretion. Finally, we examined the potential cancer therapeutic strategies targeting the different molecular events in which RAB7 is involved.
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Affiliation(s)
- Flora Guerra
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Lecce-Monteroni 165, 73100 Lecce, Italy.
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Lecce-Monteroni 165, 73100 Lecce, Italy.
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9
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Lu Q, Lu D, Shao ZM, Li DQ. Deubiquitinase ubiquitin-specific protease 9X regulates the stability and function of E3 ubiquitin ligase ring finger protein 115 in breast cancer cells. Cancer Sci 2019; 110:1268-1278. [PMID: 30689267 PMCID: PMC6447854 DOI: 10.1111/cas.13953] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 12/24/2022] Open
Abstract
The E3 ubiquitin ligase ring finger protein 115 (RNF115) is overexpressed in more than half of human breast tumors and is implicated in the pathogenesis and progression of breast cancer. However, the mechanism behind RNF115 overexpression in breast tumors remains largely unknown. Here we report that ubiquitin‐specific protease 9X (USP9X), a substrate‐specific deubiquitinating enzyme, stabilizes RNF115 and thereby regulates its biological functions in breast cancer cells. Immunoprecipitation and GST pull‐down assays showed that USP9X interacted with RNF115. Depletion of RNF115 by siRNAs or overexpression of RNF115 did not significantly affect USP9X expression. In contrast, knockdown of USP9X in breast cancer cells by siRNAs reduced RNF115 protein abundance, which was partially restored following treatment with proteasome inhibitor MG‐132. Moreover, depletion of USP9X reduced the half‐life of RNF115 and increased its ubiquitination. Conversely, overexpression of USP9X resulted in an accumulation of RNF115 protein, accompanied by a decrease in its ubiquitination. RNF115 mRNA levels were unaffected by overexpression or knockdown of USP9X. Furthermore, USP9X protein expression levels correlated positively with RNF115 in breast cancer cell lines and breast tumor samples. Importantly, reintroduction of RNF115 in USP9X‐depleted cells partially rescued the reduced proliferation, migration, and invasion of breast cancer cells by USP9X knockdown. Collectively, these findings indicate that USP9X is a stabilizer of RNF115 protein and that the USP9X‐RNF115 signaling axis is implicated in the breast cancer malignant phenotype.
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Affiliation(s)
- Qin Lu
- Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Dayun Lu
- CAS Key Laboratory of Receptor Research, Department of Analytical Chemistry, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Zhi-Ming Shao
- Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Cancer Institute, Shanghai Medical College, Fudan University, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.,Department of Breast Surgery, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Breast Cancer in Shanghai, Shanghai Medical College, Fudan University, Shanghai, China
| | - Da-Qiang Li
- Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Cancer Institute, Shanghai Medical College, Fudan University, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.,Department of Breast Surgery, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Breast Cancer in Shanghai, Shanghai Medical College, Fudan University, Shanghai, China
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10
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Selby LI, Aurelio L, Yuen D, Graham B, Johnston APR. Quantifying Cellular Internalization with a Fluorescent Click Sensor. ACS Sens 2018; 3:1182-1189. [PMID: 29676153 DOI: 10.1021/acssensors.8b00219] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ability to determine the amount of material endocytosed by a cell is important for our understanding of cell biology and in the design of effective carriers for drug delivery. To quantify internalization by fluorescence, the signal from material remaining on the cell surface must be differentiated from endocytosed material. Sensors for internalization offer advantages over traditional methods for achieving this as they exhibit improved sensitivity, allow for multiple fluorescent markers to be used simultaneously, and are amenable to high-throughput analysis. We have developed a small fluorescent internalization sensor, similar in size to a standard fluorescent dye, that can be conjugated to proteins and uses the rapid and highly specific bio-orthogonal reaction between a tetrazine and a trans-cyclooctene group to switch off the surface signal. The sensor can be attached to a variety of materials using simple chemistry and is compatible with flow cytometry and fluorescence microscopy, making it a useful tool to study the uptake of material into cells.
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Affiliation(s)
- Laura I. Selby
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria 3052, Australia
| | - Luigi Aurelio
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Daniel Yuen
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Bim Graham
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Angus P. R. Johnston
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria 3052, Australia
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11
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Yang X, Pan Y, Qiu Z, Du Z, Zhang Y, Fa P, Gorityala S, Ma S, Li S, Chen C, Wang H, Xu Y, Yan C, Ruth K, Ma Z, Zhang J. RNF126 as a Biomarker of a Poor Prognosis in Invasive Breast Cancer and CHEK1 Inhibitor Efficacy in Breast Cancer Cells. Clin Cancer Res 2018; 24:1629-1643. [PMID: 29326282 DOI: 10.1158/1078-0432.ccr-17-2242] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/10/2017] [Accepted: 01/05/2018] [Indexed: 01/20/2023]
Abstract
Purpose: (i) To investigate the expression of the E3 ligase, RNF126, in human invasive breast cancer and its links with breast cancer outcomes; and (ii) to test the hypothesis that RNF126 determines the efficacy of inhibitors targeting the cell-cycle checkpoint kinase, CHEK1.Experimental Design: A retrospective analysis by immunohistochemistry (IHC) compared RNF126 staining in 110 invasive breast cancer and 78 paired adjacent normal tissues with clinicopathologic data. Whether RNF126 controls CHEK1 expression was determined by chromatin immunoprecipitation and a CHEK1 promoter driven luciferase reporter. Staining for these two proteins by IHC using tissue microarrays was also conducted. Cell killing/replication stress induced by CHEK1 inhibition was evaluated in cells, with or without RNF126 knockdown, by MTT/colony formation, replication stress biomarker immunostaining and DNA fiber assays.Results: RNF126 protein expression was elevated in breast cancer tissue samples. RNF126 was associated with a poor clinical outcome after multivariate analysis and was an independent predictor. RNF126 promotes CHEK1 transcript expression. Critically, a strong correlation between RNF126 and CHEK1 proteins was identified in breast cancer tissue and cell lines. The inhibition of CHEK1 induced a greater cell killing and a higher level of replication stress in breast cancer cells expressing RNF126 compared to RNF126 depleted cells.Conclusions: RNF126 protein is highly expressed in invasive breast cancer tissue. The high expression of RNF126 is an independent predictor of a poor prognosis in invasive breast cancer and is considered a potential biomarker of a cancer's responsiveness to CHEK1 inhibitors. CHEK1 inhibition targets breast cancer cells expressing higher levels of RNF126 by enhancing replication stress. Clin Cancer Res; 24(7); 1629-43. ©2018 AACR.
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Affiliation(s)
- Xiaosong Yang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Department of Breast Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - You Pan
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Department of Breast Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhaojun Qiu
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Zhanwen Du
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Yao Zhang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Pengyan Fa
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | | | - Shanhuai Ma
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Shunqiang Li
- Division of Oncology Breast Oncology Section, Washington University Medical School, St. Louis, Missouri
| | - Ceshi Chen
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
| | - Hongbing Wang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland
| | - Yan Xu
- Department of Chemistry, Cleveland State University, Cleveland, Ohio.,Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Chunhong Yan
- Georgia Cancer Center, Augusta University, Augusta, Georgia
| | - Keri Ruth
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Zhefu Ma
- Department of Breast Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. .,Department of Breast Surgery & Plastic Surgery, Cancer Hospital of China Medical University, Shenyang, China
| | - Junran Zhang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio. .,Department of Radiation Oncology, The Ohio State University, Columbus, Ohio
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