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Zhou X, Wu C, Wang X, Pan N, Sun X, Chen B, Zheng S, Wei Y, Chen J, Wu Y, Zhu F, Chen J, Chen H, Wang LX. Tumor cell-released autophagosomes (TRAPs) induce PD-L1-decorated NETs that suppress T-cell function to promote breast cancer pulmonary metastasis. J Immunother Cancer 2024; 12:e009082. [PMID: 38926151 PMCID: PMC11216055 DOI: 10.1136/jitc-2024-009082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Lung metastasis is the primary cause of breast cancer-related mortality. Neutrophil extracellular traps (NETs) are involved in the progression of breast cancer. However, the mechanism of NET formation is not fully understood. This study posits that tumor cell-released autophagosomes (TRAPs) play a crucial role in this process. METHODS TRAPs were isolated from breast cancer cell lines to analyze their impact on NET formation in both human and mouse neutrophils. The study used both in vitro and in vivo models, including Toll-like receptor 4 (TLR4-/-) mice and engineered breast cancer cell lines. Immunofluorescence, ELISA, Western blotting, RNA sequencing, and flow cytometry were employed to dissect the signaling pathways leading to NET production and to explore their immunosuppressive effects, particularly focusing on the impact of NETs on T-cell function. The therapeutic potential of targeting TRAP-induced NETs and their immunosuppressive functions was evaluated using DNase I and αPD-L1 antibodies. Clinical relevance was assessed by correlating circulating levels of TRAPs and NETs with lung metastasis in patients with breast cancer. RESULTS This study showed that TRAPs induced the formation of NETs in both human and mouse neutrophils by using the high mobility group box 1 and activating the TLR4-Myd88-ERK/p38 signaling axis. More importantly, PD-L1 carried by TRAP-induced NETs inhibited T-cell function in vitro and in vivo, thereby contributing to the formation of lung premetastatic niche (PMN) immunosuppression. In contrast, Becn1 KD-4T1 breast tumors with decreased circulating TRAPs in vivo reduced the formation of NETs, which in turn attenuated the immunosuppressive effects in PMN and resulted in a reduction of breast cancer pulmonary metastasis in murine models. Moreover, treatment with αPD-L1 in combination with DNase I that degraded NETs restored T-cell function and significantly reduced tumor metastasis. TRAP levels in the peripheral blood positively correlated with NET levels and lung metastasis in patients with breast cancer. CONCLUSIONS Our results demonstrate a novel role of TRAPs in the formation of PD-L1-decorated NETs, which may provide a new strategy for early detection and treatment of pulmonary metastasis in patients with breast cancer.
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Affiliation(s)
- Xiaohe Zhou
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Chengdong Wu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Xuru Wang
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Ning Pan
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Xiaotong Sun
- Department of Laboratory Medicine, Yantai Yuhuangding Hospital, Yantai, Shandong, China
| | - Bohao Chen
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Shiya Zheng
- Department of Oncology, Southeast University Zhongda Hospital, Nanjing, Jiangsu, China
| | - Yiting Wei
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Jing Chen
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Yuyang Wu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Fengjiao Zhu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Jinpeng Chen
- Department of general surgery, Southeast University Zhongda Hospital, Nanjing, Jiangsu, China
| | - Huabiao Chen
- Institute of Biomedical Engineering and Technology, School of Medicine, Ningbo University, Ningbo, China
| | - Li-Xin Wang
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu, China
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Schmid M, Fischer P, Engl M, Widder J, Kerschbaum-Gruber S, Slade D. The interplay between autophagy and cGAS-STING signaling and its implications for cancer. Front Immunol 2024; 15:1356369. [PMID: 38660307 PMCID: PMC11039819 DOI: 10.3389/fimmu.2024.1356369] [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: 12/15/2023] [Accepted: 03/26/2024] [Indexed: 04/26/2024] Open
Abstract
Autophagy is an intracellular process that targets various cargos for degradation, including members of the cGAS-STING signaling cascade. cGAS-STING senses cytosolic double-stranded DNA and triggers an innate immune response through type I interferons. Emerging evidence suggests that autophagy plays a crucial role in regulating and fine-tuning cGAS-STING signaling. Reciprocally, cGAS-STING pathway members can actively induce canonical as well as various non-canonical forms of autophagy, establishing a regulatory network of feedback mechanisms that alter both the cGAS-STING and the autophagic pathway. The crosstalk between autophagy and the cGAS-STING pathway impacts a wide variety of cellular processes such as protection against pathogenic infections as well as signaling in neurodegenerative disease, autoinflammatory disease and cancer. Here we provide a comprehensive overview of the mechanisms involved in autophagy and cGAS-STING signaling, with a specific focus on the interactions between the two pathways and their importance for cancer.
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Affiliation(s)
- Maximilian Schmid
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
| | - Patrick Fischer
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
| | - Magdalena Engl
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
- Vienna Biocenter PhD Program, a Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Joachim Widder
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Sylvia Kerschbaum-Gruber
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Dea Slade
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
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3
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Li Y, Zheng Y, Tan X, Du Y, Wei Y, Liu S. Extracellular vesicle-mediated pre-metastatic niche formation via altering host microenvironments. Front Immunol 2024; 15:1367373. [PMID: 38495881 PMCID: PMC10940351 DOI: 10.3389/fimmu.2024.1367373] [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: 01/08/2024] [Accepted: 02/23/2024] [Indexed: 03/19/2024] Open
Abstract
The disordered growth, invasion and metastasis of cancer are mainly attributed to bidirectional cell-cell interactions. Extracellular vesicles (EVs) secreted by cancer cells are involved in orchestrating the formation of pre-metastatic niches (PMNs). Tumor-derived EVs mediate bidirectional communication between tumor and stromal cells in local and distant microenvironments. EVs carrying mRNAs, small RNAs, microRNAs, DNA fragments, proteins and metabolites determine metastatic organotropism, enhance angiogenesis, modulate stroma cell phenotypes, restructure the extracellular matrix, induce immunosuppression and modify the metabolic environment of organs. Evidence indicates that EVs educate stromal cells in secondary sites to establish metastasis-supportive microenvironments for seeding tumor cells. In this review, we provide a comprehensive overview of PMN formation and the underlying mechanisms mediated by EVs. Potential approaches to inhibit cancer metastasis by inhibiting the formation of PMNs are also presented.
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Affiliation(s)
- Ying Li
- Department of Blood Transfusion, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yan Zheng
- Department of Operating Room, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xiaojie Tan
- Department of Gastrointestinal Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yongxing Du
- Department of Pancreatic and Gastric Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yingxin Wei
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, China
| | - Shanglong Liu
- Department of Gastrointestinal Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China
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4
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Zhang M, Bi X. Heat Shock Proteins and Breast Cancer. Int J Mol Sci 2024; 25:876. [PMID: 38255948 PMCID: PMC10815085 DOI: 10.3390/ijms25020876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/01/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
Heat shock proteins (Hsps) are a group of stress-induced proteins involved in protein folding and maturation. Based on their molecular weight, Hsps can be divided into six families: small Hsps, Hsp40, Hsp60, Hsp70, Hsp90, and large Hsps. In the process of breast cancer tumorigenesis, Hsps play a central role in regulating cell reactions and functions including proliferation, metastasis, and apoptosis. Moreover, some of the critical Hsps also regulate the fine balance between the protective and destructive immunological responses within the tumor microenvironment. In this review, we systematically summarize the roles of major Hsps in breast cancer biology and point out the potential uses of these proteins in breast cancer diagnosis and therapy. Understanding the roles of different families of Hsps in breast cancer pathogenesis will help in the development of more effective prevention and treatment measures for breast cancer.
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Affiliation(s)
- Miao Zhang
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang 330006, China;
- Institute of Microbiology, Jiangxi Academy of Sciences, Nanchang 330096, China
| | - Xiaowen Bi
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang 330006, China;
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5
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Zhang Y, Pan D, Ning Z, Huang F, Wei Y, Zhang M, Zhang Y, Wang LX, Shen Y. Identifying tumor cell-released extracellular vesicles as biomarkers for breast cancer diagnosis by a three-dimensional hydrogel-based electrochemical immunosensor. J Nanobiotechnology 2023; 21:467. [PMID: 38062518 PMCID: PMC10701998 DOI: 10.1186/s12951-023-02180-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 10/26/2023] [Indexed: 12/18/2023] Open
Abstract
Tumor cell-released LC3+ extracellular vesicles (LC3+ EVs) participate in immunosuppression during autophagy and contribute to the occurrence and development of breast cancer. In view of the strong association between the LC3+ EVs and breast cancer, developing an effective strategy for the quantitative detection of LC3+ EVs levels with high sensitivity to identify LC3+ EVs as new biomarkers for accurate diagnosis of breast cancer is crucial, but yet not been reported. Herein, an ultrasensitive electrochemical immunosensor is presented for the quantitative determination of LC3+ EVs using a three-dimensional graphene oxide hydrogel-methylene blue composite as a redox probe, showing a low detection limit and a wide linear range. With this immunosensor, the expression levels of LC3+ EVs in various practical sample groups including different cancer cell lines, the peripheral blood of tumor-bearing mice before and after immunotherapy, and the peripheral blood from breast cancer patients with different subtypes and stages were clearly distinguished. This study demonstrated that LC3+ EVs were superior as biomarkers for the accurate diagnosis of breast cancer compared to traditional biomarkers, particularly for cancer subtype discrimination. This work would provide a new noninvasive detection tool for the early diagnosis and prognosis assessment of breast cancer in clinics.
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Affiliation(s)
- Yue Zhang
- Clinical Medical Laboratory Center, The Affiliated Taizhou People's Hospital of Nanjing Medical University, Taizhou, 225300, China
- Medical School, Southeast University, Nanjing, 210009, China
| | - Deng Pan
- Medical School, Southeast University, Nanjing, 210009, China
| | - Zhenqiang Ning
- Medical School, Southeast University, Nanjing, 210009, China
| | - Fang Huang
- Medical School, Southeast University, Nanjing, 210009, China
| | - Yiting Wei
- Medical School, Southeast University, Nanjing, 210009, China
| | - Mingming Zhang
- Medical School, Southeast University, Nanjing, 210009, China
| | - Yuanjian Zhang
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, China
| | - Li-Xin Wang
- Medical School, Southeast University, Nanjing, 210009, China.
| | - Yanfei Shen
- Medical School, Southeast University, Nanjing, 210009, China.
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6
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Guo S, Huang J, Li G, Chen W, Li Z, Lei J. The role of extracellular vesicles in circulating tumor cell-mediated distant metastasis. Mol Cancer 2023; 22:193. [PMID: 38037077 PMCID: PMC10688140 DOI: 10.1186/s12943-023-01909-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023] Open
Abstract
Current research has demonstrated that extracellular vesicles (EVs) and circulating tumor cells (CTCs) are very closely related in the process of distant tumor metastasis. Primary tumors are shed and released into the bloodstream to form CTCs that are referred to as seeds to colonize and grow in soil-like distant target organs, while EVs of tumor and nontumor origin act as fertilizers in the process of tumor metastasis. There is no previous text that provides a comprehensive review of the role of EVs on CTCs during tumor metastasis. In this paper, we reviewed the mechanisms of EVs on CTCs during tumor metastasis, including the ability of EVs to enhance the shedding of CTCs, protect CTCs in circulation and determine the direction of CTC metastasis, thus affecting the distant metastasis of tumors.
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Affiliation(s)
- Siyin Guo
- Division of Thyroid Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Jing Huang
- Division of Thyroid Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Genpeng Li
- Division of Thyroid Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Wenjie Chen
- Division of Thyroid Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Zhihui Li
- Division of Thyroid Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Jianyong Lei
- Division of Thyroid Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.
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7
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Patel U, Susman D, Allan AL. Influence of Extracellular Vesicles on Lung Stromal Cells during Breast Cancer Metastasis. Int J Mol Sci 2023; 24:11801. [PMID: 37511559 PMCID: PMC10380344 DOI: 10.3390/ijms241411801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
Breast cancer is a prominent cause of cancer diagnosis and death in women globally, with over 90% of deaths being attributed to complications that arise from metastasis. One of the common locations for breast cancer metastasis is the lung, which is associated with significant morbidity and mortality. Curative treatments for metastatic breast cancer patients are not available and the molecular mechanisms that underlie lung metastasis are not fully understood. In order to better treat these patients, identifying events that occur both prior to and during metastatic spread to the lung is essential. Several studies have demonstrated that breast cancer-derived extracellular vesicles secreted from the primary breast tumor play a key role in establishing the lung pre-metastatic niche to support colonization of metastatic tumor cells. In this review, we summarize recent work supporting the influence of extracellular vesicles on stromal components of the lung to construct the pre-metastatic niche and support metastasis. Furthermore, we discuss the potential clinical applications of utilizing extracellular vesicles for diagnosis and treatment. Together, this review highlights the dynamic nature of extracellular vesicles, their roles in breast cancer metastasis to the lung, and their value as potential biomarkers and therapeutics for cancer prevention.
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Affiliation(s)
- Urvi Patel
- Department of Anatomy & Cell Biology, Western University, London, ON N6A 5W9, Canada
| | - David Susman
- Department of Anatomy & Cell Biology, Western University, London, ON N6A 5W9, Canada
| | - Alison L Allan
- Departments of Anatomy & Cell Biology and Oncology, Western University, London, ON N6A 5W9, Canada
- London Regional Cancer Program, London Health Sciences Centre, London, ON N6A 5W9, Canada
- Lawson Health Research Institute, London, ON N6A 5W9, Canada
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8
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Zhang X, Wang C, Yu J, Bu J, Ai F, Wang Y, Lin J, Zhu X. Extracellular vesicles in the treatment and diagnosis of breast cancer: a status update. Front Endocrinol (Lausanne) 2023; 14:1202493. [PMID: 37534210 PMCID: PMC10393036 DOI: 10.3389/fendo.2023.1202493] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 06/30/2023] [Indexed: 08/04/2023] Open
Abstract
Breast cancer is one of the leading causes of cancer-related death in women. Currently, the treatment of breast cancer is limited by the lack of effectively targeted therapy and patients often suffer from higher severity, metastasis, and resistance. Extracellular vesicles (EVs) consist of lipid bilayers that encapsulate a complex cargo, including proteins, nucleic acids, and metabolites. These bioactive cargoes have been found to play crucial roles in breast cancer initiation and progression. Moreover, EV cargoes play pivotal roles in converting mammary cells to carcinogenic cells and metastatic foci by extensively inducing proliferation, angiogenesis, pre-metastatic niche formation, migration, and chemoresistance. The present update review mainly discusses EVs cargoes released from breast cancer cells and tumor-derived EVs in the breast cancer microenvironment, focusing on proliferation, metastasis, chemoresistance, and their clinical potential as effective biomarkers.
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Affiliation(s)
- Xiaoying Zhang
- Department of General Surgery, Huangyan Hospital, Wenzhou Medical University, Taizhou, Zhejiang, China
| | - Caizheng Wang
- Department of General Surgery, Huangyan Hospital, Wenzhou Medical University, Taizhou, Zhejiang, China
| | - Jiahui Yu
- Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Jiawen Bu
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Fulv Ai
- Department of General Surgery, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning, China
| | - Yue Wang
- Department of General Surgery, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning, China
| | - Jie Lin
- Department of General Surgery, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning, China
| | - Xudong Zhu
- Department of General Surgery, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning, China
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The pro-tumorigenic responses in metastatic niches: an immunological perspective. CLINICAL & TRANSLATIONAL ONCOLOGY : OFFICIAL PUBLICATION OF THE FEDERATION OF SPANISH ONCOLOGY SOCIETIES AND OF THE NATIONAL CANCER INSTITUTE OF MEXICO 2023; 25:333-344. [PMID: 36136272 DOI: 10.1007/s12094-022-02950-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 09/07/2022] [Indexed: 01/27/2023]
Abstract
Metastasis is the leading cause of mortality related to cancer. In the course of metastasis, cancer cells detach from the primary tumor, enter the circulation, extravasate at secondary sites, and colonize there. All of these steps are rate limiting and decrease the efficiency of metastasis. Prior to their arrival, tumor cells can modify the secondary sites. These favorable microenvironments increase the probability of successful dissemination and are referred to as pre-metastatic niches. Cancer cells use different mechanisms to induce and maintain these niches, among which immune cells play prominent roles. The immune system, including innate and adaptive, enhances recruitment, extravasation, and colonization of tumor cells at distant sites. In addition to immune cells, stromal cells can also contribute to forming pre-metastatic niches. This review summarizes the pro-metastatic responses conducted by immune cells and the assistance of stromal cells and endothelial cells in the induction of pre-metastatic niches.
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