1
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Chan FF, Yuen VWH, Shen J, Chin DWC, Law CT, Wong BPY, Chan CYK, Cheu JWS, Ng IOL, Wong CCL, Wong CM. Inhibition of CAF-1 histone chaperone complex triggers cytosolic DNA and dsRNA sensing pathways and induces intrinsic immunity of hepatocellular carcinoma. Hepatology 2023:01515467-990000000-00670. [PMID: 38051950 DOI: 10.1097/hep.0000000000000709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 11/07/2023] [Indexed: 12/07/2023]
Abstract
BACKGROUND AND AIMS Chromatin assembly factor 1 (CAF-1) is a replication-dependent epigenetic regulator that controls cell cycle progression and chromatin dynamics. In this study, we aim to investigate the immunomodulatory role and therapeutic potential of the CAF-1 complex in HCC. APPROACH AND RESULTS CAF-1 complex knockout cell lines were established using the CRISPR/Cas9 system. The effects of CAF-1 in HCC were studied in HCC cell lines, nude mice, and immunocompetent mice. RNA-sequencing, ChIP-Seq, and assay for transposase accessible chromatin with high-throughput sequencing (ATAC-Seq) were used to explore the changes in the epigenome and transcriptome. CAF-1 complex was significantly upregulated in human and mouse HCCs and was associated with poor prognosis in patients with HCC. Knockout of CAF-1 remarkably suppressed HCC growth in both in vitro and in vivo models. Mechanistically, depletion of CAF-1 induced replicative stress and chromatin instability, which eventually led to cytoplasmic DNA leakage as micronuclei. Also, chromatin immunoprecipitation sequencing analyses revealed a massive H3.3 histone variant replacement upon CAF-1 knockout. Enrichment of euchromatic H3.3 increased chromatin accessibility and activated the expression of endogenous retrovirus elements, a phenomenon known as viral mimicry. However, cytosolic micronuclei and endogenous retroviruses are recognized as ectopic elements by the stimulator of interferon genes and dsRNA viral sensing pathways, respectively. As a result, the knockout of CAF-1 activated inflammatory response and antitumor immune surveillance and thereby significantly enhanced the anticancer effect of immune checkpoint inhibitors in HCC. CONCLUSIONS Our findings suggest that CAF-1 is essential for HCC development; targeting CAF-1 may awaken the anticancer immune response and may work cooperatively with immune checkpoint inhibitor treatment in cancer therapy.
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Affiliation(s)
- For-Fan Chan
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Vincent Wai-Hin Yuen
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Jialing Shen
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Don Wai-Ching Chin
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Cheuk-Ting Law
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Bowie Po-Yee Wong
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Cerise Yuen-Ki Chan
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Jacinth Wing-Sum Cheu
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Irene Oi-Lin Ng
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Carmen Chak-Lui Wong
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Chun-Ming Wong
- State Key Laboratory of Liver Research, Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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2
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Cheu JWS, Chiu DKC, Kwan KKL, Yang C, Yuen VWH, Goh CC, Chui NNQ, Shen W, Law CT, Li Q, Zhang MS, Bao MHR, Wong BPY, Chan CYK, Liu CX, Sit GFW, Ooi ZY, Deng H, Tse APW, Ng IOL, Wong CCL. Hypoxia-inducible factor orchestrates adenosine metabolism to promote liver cancer development. Sci Adv 2023; 9:eade5111. [PMID: 37146141 PMCID: PMC10162666 DOI: 10.1126/sciadv.ade5111] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Hypoxia-induced adenosine creates an immunosuppressive tumor microenvironment (TME) and dampens the efficacy of immune checkpoint inhibitors (ICIs). We found that hypoxia-inducible factor 1 (HIF-1) orchestrates adenosine efflux through two steps in hepatocellular carcinoma (HCC). First, HIF-1 activates transcriptional repressor MXI1, which inhibits adenosine kinase (ADK), resulting in the failure of adenosine phosphorylation to adenosine monophosphate. This leads to adenosine accumulation in hypoxic cancer cells. Second, HIF-1 transcriptionally activates equilibrative nucleoside transporter 4, pumping adenosine into the interstitial space of HCC, elevating extracellular adenosine levels. Multiple in vitro assays demonstrated the immunosuppressive role of adenosine on T cells and myeloid cells. Knockout of ADK in vivo skewed intratumoral immune cells to protumorigenic and promoted tumor progression. Therapeutically, combination treatment of adenosine receptor antagonists and anti-PD-1 prolonged survival of HCC-bearing mice. We illustrated the dual role of hypoxia in establishing an adenosine-mediated immunosuppressive TME and offered a potential therapeutic approach that synergizes with ICIs in HCC.
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Affiliation(s)
- Jacinth Wing-Sum Cheu
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
| | - David Kung-Chun Chiu
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Kenneth Kin-Leung Kwan
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
| | - Chunxue Yang
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Vincent Wai-Hin Yuen
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
| | - Chi Ching Goh
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Noreen Nog-Qin Chui
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Wei Shen
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
| | - Cheuk-Ting Law
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Qidong Li
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Misty Shuo Zhang
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
| | - Macus Hao-Ran Bao
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
| | - Bowie Po-Yee Wong
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Cerise Yuen-Ki Chan
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
| | - Cindy Xinqi Liu
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Grace Fu-Wan Sit
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Zher Yee Ooi
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Haijing Deng
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Aki Pui-Wah Tse
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
| | - Irene Oi-Lin Ng
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Carmen Chak-Lui Wong
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong
- State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
- Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen University, Guangzhou, China 510120
- Shenzhen Hospital, The University of Hong Kong, Shenzhen, China
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3
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Chan CYK, Yuen VWH, Chiu DKC, Goh CC, Thu KL, Cescon DW, Soria-Bretones I, Law CT, Cheu JWS, Lee D, Tse APW, Tan KV, Zhang MS, Wong BPY, Wong CM, Khong PL, Ng IOL, Bray MR, Mak TW, Yau TCC, Wong CCL. Polo-like kinase 4 inhibitor CFI-400945 suppresses liver cancer through cell cycle perturbation and eliciting antitumor immunity. Hepatology 2023; 77:729-744. [PMID: 35302667 DOI: 10.1002/hep.32461] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 01/10/2023]
Abstract
BACKGROUND AND AIMS Prognosis of HCC remains poor due to lack of effective therapies. Immune checkpoint inhibitors (ICIs) have delayed response and are only effective in a subset of patients. Treatments that could effectively shrink the tumors within a short period of time are idealistic to be employed together with ICIs for durable tumor suppressive effects. HCC acquires increased tolerance to aneuploidy. The rapid division of HCC cells relies on centrosome duplication. In this study, we found that polo-like kinase 4 (PLK4), a centrosome duplication regulator, represents a therapeutic vulnerability in HCC. APPROACH AND RESULTS An orally available PLK4 inhibitor, CFI-400945, potently suppressed proliferating HCC cells by perturbing centrosome duplication. CFI-400945 induced endoreplication without stopping DNA replication, causing severe aneuploidy, DNA damage, micronuclei formation, cytosolic DNA accumulation, and senescence. The cytosolic DNA accumulation elicited the DEAD box helicase 41-stimulator of interferon genes-interferon regulatory factor 3/7-NF-κβ cytosolic DNA sensing pathway, thereby driving the transcription of senescence-associated secretory phenotypes, which recruit immune cells. CFI-400945 was evaluated in liver-specific p53/phosphatase and tensin homolog knockout mouse HCC models established by hydrodynamic tail vein injection. Tumor-infiltrated immune cells were analyzed. CFI-400945 significantly impeded HCC growth and increased infiltration of cluster of differentiation 4-positive (CD4 + ), CD8 + T cells, macrophages, and natural killer cells. Combination therapy of CFI-400945 with anti-programmed death-1 showed a tendency to improve HCC survival. CONCLUSIONS We show that by targeting a centrosome regulator, PLK4, to activate the cytosolic DNA sensing-mediated immune response, CFI-400945 effectively restrained tumor progression through cell cycle inhibition and inducing antitumor immunity to achieve a durable suppressive effect even in late-stage mouse HCC.
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Affiliation(s)
- Cerise Yuen-Ki Chan
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,Centre for Oncology and Immunology , Hong Kong Science Park , Hong Kong SAR , China
| | - Vincent Wai-Hin Yuen
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,Centre for Oncology and Immunology , Hong Kong Science Park , Hong Kong SAR , China
| | | | - Chi-Ching Goh
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China
| | - Kelsie L Thu
- The Campbell Family Institute for Breast Cancer Research , Princess Margaret Cancer Centre , Toronto , Ontario , Canada
| | - David W Cescon
- The Campbell Family Institute for Breast Cancer Research , Princess Margaret Cancer Centre , Toronto , Ontario , Canada
| | - Isabel Soria-Bretones
- The Campbell Family Institute for Breast Cancer Research , Princess Margaret Cancer Centre , Toronto , Ontario , Canada
| | - Cheuk-Ting Law
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China
| | - Jacinth Wing-Sum Cheu
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,Centre for Oncology and Immunology , Hong Kong Science Park , Hong Kong SAR , China
| | - Derek Lee
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,Centre for Oncology and Immunology , Hong Kong Science Park , Hong Kong SAR , China
| | - Aki Pui-Wah Tse
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,Centre for Oncology and Immunology , Hong Kong Science Park , Hong Kong SAR , China
| | - Kel Vin Tan
- Department of Diagnostic Radiology , The University of Hong Kong , Hong Kong SAR , China
| | - Misty Shuo Zhang
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,Centre for Oncology and Immunology , Hong Kong Science Park , Hong Kong SAR , China
| | - Bowie Po-Yee Wong
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China
| | - Chun-Ming Wong
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,State Key Laboratory of Liver Research , The University of Hong Kong , Hong Kong SAR , China
| | - Pek-Lan Khong
- Department of Diagnostic Radiology , The University of Hong Kong , Hong Kong SAR , China
| | - Irene Oi-Lin Ng
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,State Key Laboratory of Liver Research , The University of Hong Kong , Hong Kong SAR , China
| | - Mark R Bray
- The Campbell Family Institute for Breast Cancer Research , Princess Margaret Cancer Centre , Toronto , Ontario , Canada
| | - Tak Wah Mak
- Centre for Oncology and Immunology , Hong Kong Science Park , Hong Kong SAR , China.,The Campbell Family Institute for Breast Cancer Research , Princess Margaret Cancer Centre , Toronto , Ontario , Canada
| | - Thomas Chung-Cheung Yau
- State Key Laboratory of Liver Research , The University of Hong Kong , Hong Kong SAR , China.,Department of Medicine , The University of Hong Kong , Hong Kong SAR , China
| | - Carmen Chak-Lui Wong
- Department of Pathology , The University of Hong Kong , Hong Kong SAR , China.,Centre for Oncology and Immunology , Hong Kong Science Park , Hong Kong SAR , China.,State Key Laboratory of Liver Research , The University of Hong Kong , Hong Kong SAR , China.,Guangdong-Hong Kong Joint Laboratory for RNA Medicine , Sun Yat-Sen University , Guangzhou , China
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4
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Yuen VWH, Chiu DKC, Law CT, Cheu JWS, Chan CYK, Wong BPY, Goh CC, Zhang MS, Xue HDG, Tse APW, Zhang Y, Lau HYH, Lee D, Au-Yeung RKH, Wong CM, Wong CCL. Using mouse liver cancer models based on somatic genome editing to predict immune checkpoint inhibitor responses. J Hepatol 2023; 78:376-389. [PMID: 36455783 DOI: 10.1016/j.jhep.2022.10.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 10/10/2022] [Accepted: 10/16/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND & AIMS Tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs) are the only two classes of FDA-approved drugs for individuals with advanced hepatocellular carcinoma (HCC). While TKIs confer only modest survival benefits, ICIs have been associated with remarkable outcomes but only in the minority of patients who respond. Understanding the mechanisms that determine the efficacy of ICIs in HCC will help to stratify patients likely to respond to ICIs. This study aims to elucidate how genetic composition and specific oncogenic pathways regulate the immune composition of HCC, which directly affects response to ICIs. METHODS A collection of mouse HCCs with genotypes that closely simulate the genetic composition found in human HCCs were established using genome-editing approaches involving the delivery of transposon and CRISPR-Cas9 systems by hydrodynamic tail vein injection. Mouse HCC tumors were analyzed by RNA-sequencing while tumor-infiltrating T cells were analyzed by flow cytometry and single-cell RNA-sequencing. RESULTS Based on the CD8+ T cell-infiltration level, we characterized tumors with different genotypes into cold and hot tumors. Anti-PD-1 treatment had no effect in cold tumors but was greatly effective in hot tumors. As proof-of-concept, a cold tumor (Trp53KO/MYCOE) and a hot tumor (Keap1KO/MYCOE) were further characterized. Tumor-infiltrating CD8+ T cells from Keap1KO/MYCOE HCCs expressed higher levels of proinflammatory chemokines and exhibited enrichment of a progenitor exhausted CD8+ T-cell phenotype compared to those in Trp53KO/MYCOE HCCs. The TKI sorafenib sensitized Trp53KO/MYCOE HCCs to anti-PD-1 treatment. CONCLUSION Single anti-PD-1 treatment appears to be effective in HCCs with genetic mutations driving hot tumors, while combined anti-PD-1 and sorafenib treatment may be more appropriate in HCCs with genetic mutations driving cold tumors. IMPACT AND IMPLICATIONS Genetic alterations of different driver genes in mouse liver cancers are associated with tumor-infiltrating CD8+ T cells and anti-PD-1 response. Mouse HCCs with different genetic compositions can be grouped into hot and cold tumors based on the level of tumor-infiltrating CD8+ T cells. This study provides proof-of-concept evidence to show that hot tumors are responsive to anti-PD-1 treatment while cold tumors are more suitable for combined treatment with anti-PD-1 and sorafenib. Our study might help to guide the design of patient stratification systems for single or combined treatments involving anti-PD-1.
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Affiliation(s)
- Vincent Wai-Hin Yuen
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | | | | | - Jacinth Wing-Sum Cheu
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Cerise Yuen-Ki Chan
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Bowie Po-Yee Wong
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | | | - Misty Shuo Zhang
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Helen Do-Gai Xue
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Aki Pui-Wah Tse
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Yan Zhang
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | | | - Derek Lee
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Rex K H Au-Yeung
- Department of Pathology; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Chun-Ming Wong
- Department of Pathology; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Carmen Chak-Lui Wong
- Department of Pathology; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong; Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China.
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5
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Fu WY, Hung KW, Lau SF, Butt B, Yuen VWH, Fu G, Chan IC, Ip FCF, Fu AKY, Ip NY. Rhynchophylline Administration Ameliorates Amyloid-β Pathology and Inflammation in an Alzheimer's Disease Transgenic Mouse Model. ACS Chem Neurosci 2021; 12:4249-4256. [PMID: 34738783 DOI: 10.1021/acschemneuro.1c00600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD), the most common neurodegenerative disease, has limited treatment options. As such, extensive studies have been conducted to identify novel therapeutic approaches. We previously reported that rhynchophylline (Rhy), a small molecule EphA4 inhibitor, rescues impaired hippocampal synaptic plasticity and cognitive dysfunctions in APP/PS1 mice, an AD transgenic mouse model. To assess whether Rhy can be developed as an alternative treatment for AD, it is important to examine its pharmacokinetics and effects on other disease-associated pathologies. Here, we show that Rhy ameliorates amyloid plaque burden and reduces inflammation in APP/PS1 mice. Transcriptome analysis revealed that Rhy regulates various molecular pathways in APP/PS1 mouse brains associated with amyloid metabolism and inflammation, specifically the ubiquitin proteasome system, angiogenesis, and microglial functional states. These results show that Rhy, which is blood-brain barrier permeable, is beneficial to amyloid pathology and regulates multiple molecular pathways.
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Affiliation(s)
- Wing-Yu Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong 999077China
| | - Kwok-Wang Hung
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
| | - Shun-Fat Lau
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong 999077China
| | - Busma Butt
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
| | - Vincent Wai-Hin Yuen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
| | - Guangmiao Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
| | - Ivy C. Chan
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
| | - Fanny C. F. Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong 999077China
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen−Hong Kong Institute of Brain Science, Shenzhen, Guangdong 518057, China
| | - Amy K. Y. Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong 999077China
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen−Hong Kong Institute of Brain Science, Shenzhen, Guangdong 518057, China
| | - Nancy Y. Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong 999077China
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen−Hong Kong Institute of Brain Science, Shenzhen, Guangdong 518057, China
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6
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Lee D, Zhang MS, Tsang FHC, Bao MHR, Xu IMJ, Lai RKH, Chiu DKC, Tse APW, Law CT, Chan CYK, Yuen VWH, Chui NNQ, Ng IOL, Wong CM, Wong CCL. Adaptive and Constitutive Activations of Malic Enzymes Confer Liver Cancer Multilayered Protection Against Reactive Oxygen Species. Hepatology 2021; 74:776-796. [PMID: 33619771 DOI: 10.1002/hep.31761] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 12/18/2020] [Accepted: 01/03/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND AND AIMS HCC undergoes active metabolic reprogramming. Reactive oxygen species (ROS) are excessively generated in cancer cells and are neutralized by NADPH. Malic enzymes (MEs) are the less studied NADPH producers in cancer. APPROACH AND RESULTS We found that ME1, but not ME3, was regulated by the typical oxidative stress response pathway mediated by kelch-like ECH associated protein 1/nuclear factor erythroid 2-related factor (NRF2). Surprisingly, ME3 was constitutively induced by superenhancers. Disruption of any ME regulatory pathways decelerated HCC progression and sensitized HCC to sorafenib. Therapeutically, simultaneous blockade of NRF2 and a superenhancer complex completely impeded HCC growth. We show that superenhancers allow cancer cells to counteract the intrinsically high level of ROS through constitutively activating ME3 expression. When HCC cells encounter further episodes of ROS insult, NRF2 allows cancer cells to adapt by transcriptionally activating ME1. CONCLUSIONS Our study reveals the complementary regulatory mechanisms which control MEs and provide cancer cells multiple layers of defense against oxidative stress. Targeting both regulatory mechanisms represents a potential therapeutic approach for HCC treatment.
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Affiliation(s)
- Derek Lee
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Misty Shuo Zhang
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Felice Ho-Ching Tsang
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Macus Hao-Ran Bao
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Iris Ming-Jing Xu
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Robin Kit-Ho Lai
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - David Kung-Chun Chiu
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Aki Pui-Wah Tse
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Cheuk-Ting Law
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Cerise Yuen-Ki Chan
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Vincent Wai-Hin Yuen
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Noreen Nog-Qin Chui
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong
| | - Irene Oi-Lin Ng
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong.,State Key Laboratory of Liver ResearchThe University of Hong KongHong KongHong Kong
| | - Chun-Ming Wong
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong.,State Key Laboratory of Liver ResearchThe University of Hong KongHong KongHong Kong
| | - Carmen Chak-Lui Wong
- Department of PathologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongHong Kong.,State Key Laboratory of Liver ResearchThe University of Hong KongHong KongHong Kong
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7
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Abstract
The liver has strong innate immunity to counteract pathogens from the gastrointestinal tract. During the development of liver cancer, which is typically driven by chronic inflammation, the composition and biological roles of the innate immune cells are extensively altered. Hypoxia is a common finding in all stages of liver cancer development. Hypoxia drives the stabilization of hypoxia-inducible factors (HIFs), which act as central regulators to dampen the innate immunity of liver cancer. HIF signaling in innate immune cells and liver cancer cells together favors the recruitment and maintenance of pro-tumorigenic immune cells and the inhibition of anti-tumorigenic immune cells, promoting immune evasion. HIFs represent attractive therapeutic targets to inhibit the formation of an immunosuppressive microenvironment and growth of liver cancer.
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Affiliation(s)
| | - Carmen Chak-Lui Wong
- Department of Pathology and.,State Key Laboratory of Liver Research, University of Hong Kong, Hong Kong, China
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Bao MHR, Yang C, Tse APW, Wei L, Lee D, Zhang MS, Goh CC, Chiu DKC, Yuen VWH, Law CT, Chin WC, Chui NNQ, Wong BPY, Chan CYK, Ng IOL, Chung CYS, Wong CM, Wong CCL. Genome-wide CRISPR-Cas9 knockout library screening identified PTPMT1 in cardiolipin synthesis is crucial to survival in hypoxia in liver cancer. Cell Rep 2021; 34:108676. [PMID: 33503428 DOI: 10.1016/j.celrep.2020.108676] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 11/11/2020] [Accepted: 12/30/2020] [Indexed: 12/17/2022] Open
Abstract
Hypoxia, low oxygen (O2), is a key feature of all solid cancers, including hepatocellular carcinoma (HCC). Genome-wide CRISPR-Cas9 knockout library screening is used to identify reliable therapeutic targets responsible for hypoxic survival in HCC. We find that protein-tyrosine phosphatase mitochondrial 1 (PTPMT1), an important enzyme for cardiolipin (CL) synthesis, is the most significant gene and ranks just after hypoxia-inducible factor (HIF)-1α and HIF-1β as crucial to hypoxic survival. CL constitutes the mitochondrial membrane and ensures the proper assembly of electron transport chain (ETC) complexes for efficient electron transfer in respiration. ETC becomes highly unstable during hypoxia. Knockout of PTPMT1 stops the maturation of CL and impairs the assembly of ETC complexes, leading to further electron leakage and ROS accumulation at ETC in hypoxia. Excitingly, HCC cells, especially under hypoxic conditions, show great sensitivity toward PTPMT1 inhibitor alexidine dihydrochloride (AD). This study unravels the protective roles of PTPMT1 in hypoxic survival and cancer development.
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Affiliation(s)
| | - Chunxue Yang
- Department of Pathology, The University of Hong Kong, Hong Kong
| | - Aki Pui-Wah Tse
- Department of Pathology, The University of Hong Kong, Hong Kong
| | - Lai Wei
- Department of Pathology, The University of Hong Kong, Hong Kong
| | - Derek Lee
- Department of Pathology, The University of Hong Kong, Hong Kong
| | | | - Chi Ching Goh
- Department of Pathology, The University of Hong Kong, Hong Kong
| | | | | | - Cheuk-Ting Law
- Department of Pathology, The University of Hong Kong, Hong Kong
| | - Wai-Ching Chin
- Department of Pathology, The University of Hong Kong, Hong Kong
| | | | | | | | - Irene Oi-Lin Ng
- Department of Pathology, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Clive Yik-Sham Chung
- Department of Pathology, The University of Hong Kong, Hong Kong; School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Chun-Ming Wong
- Department of Pathology, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong.
| | - Carmen Chak-Lui Wong
- Department of Pathology, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong.
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Chiu DKC, Yuen VWH, Cheu JWS, Wei LL, Ting V, Fehlings M, Sumatoh H, Nardin A, Newell EW, Ng IOL, Yau TCC, Wong CM, Wong CCL. Hepatocellular Carcinoma Cells Up-regulate PVRL1, Stabilizing PVR and Inhibiting the Cytotoxic T-Cell Response via TIGIT to Mediate Tumor Resistance to PD1 Inhibitors in Mice. Gastroenterology 2020; 159:609-623. [PMID: 32275969 DOI: 10.1053/j.gastro.2020.03.074] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 03/25/2020] [Accepted: 03/29/2020] [Indexed: 12/26/2022]
Abstract
BACKGROUND & AIMS Immune checkpoint inhibitors are effective in the treatment of some hepatocellular carcinomas (HCCs), but these tumors do not always respond to inhibitors of programmed cell death 1 (PDCD1, also called PD1). We investigated mechanisms of resistance of liver tumors in mice to infiltrating T cells. METHODS Mice were given hydrodynamic tail vein injections of clustered regularly interspaced short palindromic repeats-Cas9 (CRISPR-Cas9) and transposon vectors to disrupt Trp53 and overexpress C-Myc (Trp53KO/C-MycOE mice). Pvrl1 and Pvrl3 were knocked down in Hepa1-6 cells by using short hairpin RNAs. Hepa1-6 cells were injected into livers of C57BL/6 mice; some mice were given intraperitoneal injections of antibodies against PD1, T-cell immunoreceptor with Ig and ITIM domains (TIGIT), or CD8 before the cancer cells were injected. Liver tissues were collected from mice and analyzed by histology, immunohistochemistry, and quantitative real-time polymerase chain reaction; tumors were analyzed by mass cytometry using markers to detect T cells and other lymphocytes. We obtained HCC and nontumorous liver tissues and clinical data from patients who underwent surgery in Hong Kong and analyzed the tissues by immunohistochemistry. RESULTS Trp53KO/C-MycOE mice developed liver tumors in 3-5 weeks; injections of anti-PD1 did not slow tumor development. Tumors from mice given anti-PD1 had larger numbers of memory CD8+ T cells (CD44+CD62L-KLRG1int) and T cells that expressed PD1, lymphocyte activating 3 (LAG3), and TIGIT compared with mice not given the antibody. HCC tissues from patients had higher levels of PVRL1 messenger RNA and protein than nontumorous tissues. Increased PVRL1 was associated with shorter times of disease-free survival. Knockdown of Pvrl1 in Hepa1-6 cells caused them to form smaller tumors in mice, infiltrated by higher numbers of CD8+ T cells that expressed the inhibitory protein TIGIT; these effects were not observed in mice with depletion of CD8+ T cells. In Hepa1-6 cells, PVRL1 stabilized cell surface PVR, which interacted with TIGIT on CD8+ T cells; knockdown of Pvrl1 reduced cell-surface levels of PVR but not levels of Pvr messenger RNA. In Trp53KO/C-MycOE mice and mice with tumors grown from Hepa1-6 cells, injection of the combination of anti-PD1 and anti-TIGIT significantly reduced tumor growth, increased the ratio of cytotoxic to regulatory T cells in tumors, and prolonged survival. CONCLUSIONS PVRL1, which is up-regulated by HCC cells, stabilizes cell surface PVR, which interacts with TIGIT, an inhibitory molecule on CD8+ effector memory T cells. This suppresses the ant-tumor immune response. Inhibitors of PVRL1/TIGIT, along with anti-PD1 might be developed for treatment of HCC.
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Affiliation(s)
| | | | | | - Larry Lai Wei
- Department of Pathology, The University of Hong Kong, Hong Kong
| | - Vox Ting
- Department of Medicine, The University of Hong Kong, Hong Kong
| | | | | | | | - Evan W Newell
- ImmunoSCAPE Pte Ltd, Singapore; Vaccine and Infections Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Irene Oi-Lin Ng
- Department of Pathology, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Thomas Chung-Cheung Yau
- Department of Medicine, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Chun-Ming Wong
- Department of Pathology, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Carmen Chak-Lui Wong
- Department of Pathology, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong.
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Lee D, Xu IMJ, Chiu DKC, Leibold J, Tse APW, Bao MHR, Yuen VWH, Chan CYK, Lai RKH, Chin DWC, Chan DFF, Cheung TT, Chok SH, Wong CM, Lowe SW, Ng IOL, Wong CCL. Induction of Oxidative Stress Through Inhibition of Thioredoxin Reductase 1 Is an Effective Therapeutic Approach for Hepatocellular Carcinoma. Hepatology 2019; 69:1768-1786. [PMID: 30561826 PMCID: PMC8690574 DOI: 10.1002/hep.30467] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 11/25/2018] [Indexed: 12/14/2022]
Abstract
Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancers worldwide which lacks effective treatment. Cancer cells experience high levels of oxidative stress due to increased generation of reactive oxygen species (ROS). Increased antioxidant-producing capacity is therefore found in cancer cells to counteract oxidative stress. The thioredoxin system is a ubiquitous mammalian antioxidant system which scavenges ROS, and we demonstrate that it is vital for HCC growth as it maintains intracellular reduction-oxidation (redox) homeostasis. Transcriptome sequencing in human HCC samples revealed significant overexpression of thioredoxin reductase 1 (TXNRD1), the cytosolic subunit and key enzyme of the thioredoxin system, with significant correlations to poorer clinicopathological features and patient survival. Driven by the transcriptional activation of nuclear factor (erythroid-derived 2)-like 2, the master protector against oxidative stress, TXNRD1 counteracts intracellular ROS produced in human HCC. Inhibition of TXNRD1 through genetic inhibition hindered the proliferation of HCC cells and induced apoptosis in vitro. Administration of the pharmacological TXNRD1 inhibitor auranofin (AUR) effectively suppressed the growth of HCC tumors induced using the hydrodynamic tail vein injection and orthotopic implantation models in vivo. Furthermore, AUR sensitized HCC cells toward the conventional therapeutic sorafenib. Conclusion: Our study highlights the reliance of HCC cells on antioxidants for redox homeostasis and growth advantage; targeting TXNRD1 resulted in dramatic accumulation of ROS, which was found to be an effective approach for the suppression of HCC tumor growth.
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Affiliation(s)
- Derek Lee
- Department of Pathology, The University of Hong Kong, Hong Kong
| | | | | | - Josef Leibold
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Aki Pui-Wah Tse
- Department of Pathology, The University of Hong Kong, Hong Kong
| | | | | | | | | | | | | | - Tan-To Cheung
- Department of Surgery, The University of Hong Kong, Hong Kong,State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong
| | - Siu-Ho Chok
- Department of Surgery, The University of Hong Kong, Hong Kong,State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong
| | - Chun-Ming Wong
- Department of Pathology, The University of Hong Kong, Hong Kong,State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong
| | - Scott W. Lowe
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Irene Oi-Lin Ng
- Department of Pathology, The University of Hong Kong, Hong Kong,State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong,Correspondence: Dr Carmen Chak-Lui Wong, T8-010, Block T, Queen Mary Hospital, 102 Pokfulam Road, Pokfulam, Hong Kong, Phone: (852) 2255-5077, Fax: (852) 2872-5197, , or, Professor Irene Oi-Lin Ng, T7-018, Block T, Queen Mary Hospital, 102 Pokfulam Road, Pokfulam, Hong Kong, Phone: (852) 2255-2658, Fax: (852) 2872-5197,
| | - Carmen Chak-Lui Wong
- Department of Pathology, The University of Hong Kong, Hong Kong,State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong,Correspondence: Dr Carmen Chak-Lui Wong, T8-010, Block T, Queen Mary Hospital, 102 Pokfulam Road, Pokfulam, Hong Kong, Phone: (852) 2255-5077, Fax: (852) 2872-5197, , or, Professor Irene Oi-Lin Ng, T7-018, Block T, Queen Mary Hospital, 102 Pokfulam Road, Pokfulam, Hong Kong, Phone: (852) 2255-2658, Fax: (852) 2872-5197,
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Abstract
Metastasis is considered the latest stage of cancer development; however, metastasis occurs earlier than it can be detected. Metastatic sites are actively remodeled by secretory factors including growth factors, chemokines and cytokines, extracellular matrix (ECM) enzymes, and exosomes produced by the primary cancer tissues. Many of the associated-secretory factors are abundantly induced by inflammation and hypoxia. These secretory factors modify the ECM, immune composition, and blood vessel permeability of the future metastatic sites, a process termed 'metastatic niche formation.' In general, ECM is modified to enhance the attachment of other cell types or cancer cells to establish a growth-factor rich metastatic niche. Immune-suppressive cells such as tumor-associated macrophages (TAMs) and regulatory T cells (Tregs) dominate the metastatic niche to allow metastatic cancer cells to bypass immune surveillance and propagate. Endothelial cell-to-cell junctions of blood vessels are loosened to enhance the penetrance of metastatic cancer cells to the metastatic sites. Different metastatic tissues have unique ECM constituents, resident immune cells, and anatomical positions linked with the circulatory system; therefore, many cancer types have their own metastatic pattern, and they favor metastasis to specific organs. Some of the remodeling events represent the earliest step of metastasis, even preceding the detachment of cancer cells from the primary tumor site. Understanding how the metastatic niche is formed is important for the development of drugs to prevent the earliest step of metastasis and advance our understanding of organotrophic metastasis. This review summarizes the major findings in the field of metastatic niche highlighting the role of hypoxia.
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Chiu DKC, Xu IMJ, Lai RKH, Tse APW, Law DCT, Yuen VWH, Wei LL, Koh HY, Wong CM, Ng IOL, Wong CCL. Abstract 2415: HEY1 counteracts hypoxia-induced oxidative stress via transcriptionally repressing PINK1 in hepatocellular carcinoma. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-2415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background and Objective: Excessive accumulation of oxidative stress/reactive oxygen species (ROS) can be harmful to cancer cells. Hypoxia or O2 deprivation, which is commonly found in hepatocellular carcinoma (HCC), is a crucial factor that contributes to elevated ROS level in HCC cells as hypoxia causes inefficient transfer of electrons in the mitochondria. To survive, HCC cells need to devise strategies to counteract and balance hypoxia-induced oxidative stress. While it is known that hypoxia inducible factors (HIFs) are essential to metabolic reprogramming in HCC cells under hypoxia, there are significant gaps in knowledge about underlying mechanisms and transcriptional targets of HIFs.
Experimental Procedures: Gene profiling of HCC cell lines (exposed to 20% and 1% O2) was analyzed by transcriptome sequencing to identify novel candidate responsible for counteracting hypoxia-induced oxidative stress. ShRNA-mediated gene silencing and gene activation by CRISPR-dCas9 system were used to modify transcriptional expression of HEY1 for different functional assays. Transmission electron microscopy was used to visualize the mitochondrial structure. Orthotopic and subcutaneous HCC implantation models were used to evaluate the role of HEY1 in HCC progression. Transcriptome sequencing and ChIP assay were performed to identify novel transcriptional targets of HEY1.
Results: We showed that transcriptional repressor HEY1 was induced under hypoxia and directly regulated by HIF-1α. Overexpression of HEY1 was associated with poor overall survival in HCC patients. Importantly, we identified PINK1 as a novel repression target of HEY1. PINK1 is known to protect cells against mitochondrial dysfunction. We demonstrated that HEY1 actively repressed PINK1 and downregulation of PINK1 led to loss of mitochondrial mass and impaired mitochondrial cristae formation, subsequently decreasing intracellular ROS level. Downregulation of PINK also associated with poor overall survival and decrease-free in HCC patients. Genetic ablation of HEY1 in HCC cells profoundly reduced tumor growth and lung metastasis while genetic ablation of PINK1 in HCC cells reversely promoted HCC growth. Strikingly, HEY1 and PINK1 expressions reversely correlated in human HCC tissues.
Conclusion: This study unprecedentedly identifies an upstream regulatory mechanism of PINK1, which controls the oxidative stress in HCC cells. It also reveals a novel molecular mechanism by which ablation of HEY1 leads to elevation of oxidative stress, making HCC cells more vulnerable. Targeting HEY1 represents an attractive therapeutic approach against HCC.
Citation Format: David Kung-Chun Chiu, Iris Ming-Jing Xu, Robin Kit-Ho Lai, Aki Pui-Wah Tse, Dicky Cheuk-Ting Law, Vincent Wai-Hin Yuen, Larry Lai Wei, Hui-Yu Koh, Chun-Ming Wong, Irene Oi-Lin Ng, Carmen Chak-Lui Wong. HEY1 counteracts hypoxia-induced oxidative stress via transcriptionally repressing PINK1 in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2415.
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Affiliation(s)
| | | | | | | | | | | | | | - Hui-Yu Koh
- Univ. of Hong Kong, Hong Kong, Hong Kong
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