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BAF complex-mediated chromatin relaxation is required for establishment of X chromosome inactivation. Nat Commun 2022; 13:1658. [PMID: 35351876 PMCID: PMC8964718 DOI: 10.1038/s41467-022-29333-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 03/10/2022] [Indexed: 12/12/2022] Open
Abstract
The process of epigenetic silencing, while fundamentally important, is not yet completely understood. Here we report a replenishable female mouse embryonic stem cell (mESC) system, Xmas, that allows rapid assessment of X chromosome inactivation (XCI), the epigenetic silencing mechanism of one of the two X chromosomes that enables dosage compensation in female mammals. Through a targeted genetic screen in differentiating Xmas mESCs, we reveal that the BAF complex is required to create nucleosome-depleted regions at promoters on the inactive X chromosome during the earliest stages of establishment of XCI. Without this action gene silencing fails. Xmas mESCs provide a tractable model for screen-based approaches that enable the discovery of unknown facets of the female-specific process of XCI and epigenetic silencing more broadly. Female embryonic stem cells (ESCs) are the ideal model to study X chromosome inactivation (XCI) establishment; however, these cells are challenging to keep in culture. Here the authors create fluorescent ‘Xmas’ reporter mice as a renewable source of ESCs and show nucleosome remodelers Smarcc1 and Smarca4 create a nucleosome-free promoter region prior to the establishment of silencing.
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Fan C, Qu H, Wang X, Sobhani N, Wang L, Liu S, Xiong W, Zeng Z, Li Y. Cancer/testis antigens: from serology to mRNA cancer vaccine. Semin Cancer Biol 2021; 76:218-231. [PMID: 33910064 DOI: 10.1016/j.semcancer.2021.04.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 02/01/2023]
Abstract
Cancer/testis antigens (CTAs) are a group of tumor antigens expressed in numerous cancer tissues, as well as in the testis and placental tissues. There are over 200 CTAs supported by serology and expression data. The expression patterns of CTAs reflect the similarities between the processes of gametogenesis and tumorigenesis. It is notable that CTAs are highly expressed in three types of cancers (lung cancer, bladder cancer, and skin cancer), all of which have a metal etiology. Here, we review the expression, regulation, and function of CTAs and their translational prospects as cancer biomarkers and treatment targets. Many CTAs are highly immunogenic, tissue-specific, and frequently expressed in cancer tissues but not under physiological conditions, rendering them promising candidates for cancer detection. Some CTAs are associated with clinical outcomes, so they may serve as prognostic biomarkers. A small number of CTAs are membrane-bound, making them ideal targets for chimeric antigen receptor (CAR) T cells. Mounting evidence suggests that CTAs induce humoral or cellular immune responses, providing cancer immunotherapeutic opportunities for T-cell receptors (TCRs), CAR T cell, antibody-based therapy and peptide- or mRNA-based vaccines. Indeed, CTAs are the dominating non-mutated targets in mRNA cancer vaccine development. Clinical trials on CTA TCR and vaccines have shown effectiveness, safety, and tolerance, but these successes are limited to a small number of patients. In-depth studies on CTA expression and function are needed to improve CTA-based immunotherapy.
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Affiliation(s)
- Chunmei Fan
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medicine, Central South University, Changsha, Hunan, China; Section of Epidemiology and Population Science, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, United States
| | - Hongke Qu
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medicine, Central South University, Changsha, Hunan, China
| | - Xu Wang
- Section of Epidemiology and Population Science, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, United States
| | - Navid Sobhani
- Section of Epidemiology and Population Science, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, United States
| | - Leiming Wang
- Section of Epidemiology and Population Science, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, United States
| | - Shuanglin Liu
- Section of Epidemiology and Population Science, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, United States
| | - Wei Xiong
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medicine, Central South University, Changsha, Hunan, China
| | - Zhaoyang Zeng
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medicine, Central South University, Changsha, Hunan, China.
| | - Yong Li
- Section of Epidemiology and Population Science, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, United States.
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