1
|
Sood V, Holewinski R, Andresson T, Larson DR, Misteli T. Identification of molecular determinants of gene-specific bursting patterns by high-throughput imaging screens. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.597999. [PMID: 38903099 PMCID: PMC11188098 DOI: 10.1101/2024.06.08.597999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Stochastic transcriptional bursting is a universal property of active genes. While different genes exhibit distinct bursting patterns, the molecular mechanisms for gene-specific stochastic bursting are largely unknown. We have developed and applied a high-throughput-imaging based screening strategy to identify cellular factors and molecular mechanisms that determine the bursting behavior of human genes. Focusing on epigenetic regulators, we find that protein acetylation is a strong acute modulator of burst frequency, burst size and heterogeneity of bursting. Acetylation globally affects the Off-time of genes but has gene-specific effects on the On-time. Yet, these effects are not strongly linked to promoter acetylation, which do not correlate with bursting properties, and forced promoter acetylation has variable effects on bursting. Instead, we demonstrate acetylation of the Integrator complex as a key determinant of gene bursting. Specifically, we find that elevated Integrator acetylation decreases bursting frequency. Taken together our results suggest a prominent role of non-histone proteins in determining gene bursting properties, and they identify histone-independent acetylation of a transcription cofactor as an allosteric modulator of bursting via a far-downstream bursting checkpoint.
Collapse
Affiliation(s)
- Varun Sood
- National Cancer Institute, Bethesda, MD, USA
| | - Ronald Holewinski
- Protein Characterization Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Thorkell Andresson
- Protein Characterization Laboratory, National Cancer Institute, Frederick, MD, USA
| | | | - Tom Misteli
- National Cancer Institute, Bethesda, MD, USA
| |
Collapse
|
2
|
Varisli L, Dancik GM, Tolan V, Vlahopoulos S. Critical Roles of SRC-3 in the Development and Progression of Breast Cancer, Rendering It a Prospective Clinical Target. Cancers (Basel) 2023; 15:5242. [PMID: 37958417 PMCID: PMC10648290 DOI: 10.3390/cancers15215242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023] Open
Abstract
Breast cancer (BCa) is the most frequently diagnosed malignant tumor in women and is also one of the leading causes of cancer-related death. Most breast tumors are hormone-dependent and estrogen signaling plays a critical role in promoting the survival and malignant behaviors of these cells. Estrogen signaling involves ligand-activated cytoplasmic estrogen receptors that translocate to the nucleus with various co-regulators, such as steroid receptor co-activator (SRC) family members, and bind to the promoters of target genes and regulate their expression. SRC-3 is a member of this family that interacts with, and enhances, the transcriptional activity of the ligand activated estrogen receptor. Although SRC-3 has important roles in normal homeostasis and developmental processes, it has been shown to be amplified and overexpressed in breast cancer and to promote malignancy. The malignancy-promoting potential of SRC-3 is diverse and involves both promoting malignant behavior of tumor cells and creating a tumor microenvironment that has an immunosuppressive phenotype. SRC-3 also inhibits the recruitment of tumor-infiltrating lymphocytes with effector function and promotes stemness. Furthermore, SRC-3 is also involved in the development of resistance to hormone therapy and immunotherapy during breast cancer treatment. The versatility of SRC-3 in promoting breast cancer malignancy in this way makes it a good target, and methodical targeting of SRC-3 probably will be important for the success of breast cancer treatment.
Collapse
Affiliation(s)
- Lokman Varisli
- Department of Molecular Biology and Genetics, Science Faculty, Dicle University, Diyarbakir 21280, Turkey;
| | - Garrett M. Dancik
- Department of Computer Science, Eastern Connecticut State University, Willimantic, CT 06226, USA;
| | - Veysel Tolan
- Department of Molecular Biology and Genetics, Science Faculty, Dicle University, Diyarbakir 21280, Turkey;
| | - Spiros Vlahopoulos
- First Department of Pediatrics, National and Kapodistrian University of Athens, Thivon & Levadeias 8, Goudi, 11527 Athens, Greece
| |
Collapse
|
3
|
Kang L, Liu Y, He J, Wang Y, Xue M, Wu X, Wang Z, Zhang Y, Chu M, Li J, Wei W, Li J, Li E, Liao L, Xiao J, Zhang R, Xu L, Wong J. GSK3β-driven SOX2 overexpression is a targetable vulnerability in esophageal squamous cell carcinoma. Oncogene 2023; 42:2297-2314. [PMID: 37349645 DOI: 10.1038/s41388-023-02748-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/06/2023] [Accepted: 06/08/2023] [Indexed: 06/24/2023]
Abstract
Esophageal squamous cell carcinoma (ESCC) is one of the deadliest forms of human malignancy that currently lacks approved targeted therapeutics. Accumulating evidence suggests that SOX2 overexpression is a key driving factor for ESCC and various squamous cell carcinoma. Here, through screening a small-molecule kinase inhibitor library, we identified GSK3β as a kinase that is critically required for robust SOX2 expression in ESCC cells. GSK3β did not promote SOX2 transcriptionally but was required for SOX2 protein stability. We demonstrated that GSK3β interacts with and phosphorylates SOX2 at residue S251, which blocks SOX2 from ubiquitination and proteasome-dependent degradation instigated by ubiquitin E3 ligase CUL4ADET1-COP1. Pharmacological inhibition or knockdown of GSK3β by RNA interference selectively impaired SOX2-positive ESCC cell proliferation, cancer stemness, and tumor growth in mouse xenograft model, suggesting that GSK3β promotes ESCC tumorigenesis primarily by driving SOX2 overexpression. GSK3β was found to be frequently overexpressed in clinical esophageal tumors, and there was a positive correlation between GSK3β and SOX2 protein levels. Notably, we found that SOX2 enhanced GSK3β expression transcriptionally, suggesting the existence of a vicious cycle that drives a coordinated GSK3β and SOX2 overexpression in ESCC cells. Finally, we demonstrated in tumor xenograft model that GSK3β inhibitor AR-A014418 was effective in suppressing SOX2-positive ESCC tumor progression and inhibited tumor progression cooperatively with chemotherapeutic agent carboplatin. In conclusion, we uncovered a novel role for GSK3β in driving SOX2 overexpression and tumorigenesis and provided evidence that targeting GSK3β may hold promise for the treatment of recalcitrant ESCCs.
Collapse
Affiliation(s)
- Li Kang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
- Joint Center for Translational Medicine, Fengxian District Central Hospital, 6600th Nanfeng Road, Fengxian District, Shanghai, China
| | - Yujie Liu
- Department of Orthopedic Oncology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Jianzhong He
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Institute of Basic Medical Science, Cancer Research Center, Shantou University Medical College, Shantou, Guangdong, China
| | - Yaling Wang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Mengyang Xue
- The Third School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Department of Obstetrics and Gynecology, Fengxian Central Hospital affiliated to the Southern Medical University, Shanghai, China
| | - Xin Wu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhen Wang
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Yunpeng Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Manyu Chu
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Institute of Basic Medical Science, Cancer Research Center, Shantou University Medical College, Shantou, Guangdong, China
| | - Jialun Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Wei Wei
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Jiwen Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Enmin Li
- Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou, Guangdong, China
| | - Lujian Liao
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Jianru Xiao
- Department of Orthopedic Oncology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Rong Zhang
- Department of Obstetrics and Gynecology, Fengxian Central Hospital affiliated to the Southern Medical University, Shanghai, China
| | - Liyan Xu
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Institute of Basic Medical Science, Cancer Research Center, Shantou University Medical College, Shantou, Guangdong, China.
| | - Jiemin Wong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China.
- Joint Center for Translational Medicine, Fengxian District Central Hospital, 6600th Nanfeng Road, Fengxian District, Shanghai, China.
| |
Collapse
|
4
|
SOX2 Modulates the Nuclear Organization and Transcriptional Activity of the Glucocorticoid Receptor. J Mol Biol 2022; 434:167869. [PMID: 36309135 DOI: 10.1016/j.jmb.2022.167869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/07/2022] [Accepted: 10/19/2022] [Indexed: 11/07/2022]
Abstract
Steroid receptors (SRs) are ligand-dependent transcription factors (TFs) relevant to key cellular processes in both physiology and pathology, including some types of cancer. SOX2 is a master TF of pluripotency and self-renewal of embryonic stem cells, and its dysregulation is also associated with various types of human cancers. A potential crosstalk between these TFs could be relevant in malignant cells yet, to the best of our knowledge, no formal study has been performed thus far. Here we show, by quantitative live-cell imaging microscopy, that ectopic expression of SOX2 disrupts the formation of hormone-dependent intranuclear condensates of many steroid receptors (SRs), including those formed by the glucocorticoid receptor (GR). SOX2 also reduces GR's binding to specific DNA targets and modulates its transcriptional activity. SOX2-driven effects on GR condensates do not require the intrinsically disordered N-terminal domain of the receptor and, surprisingly, neither relies on GR/SOX2 interactions. SOX2 also alters the intranuclear dynamics and compartmentalization of the SR coactivator NCoA-2 and impairs GR/NCoA-2 interactions. These results suggest an indirect mechanism underlying SOX2-driven effects on SRs involving this coactivator. Together, these results highlight that the transcriptional program elicited by GR relies on its nuclear organization and is intimately linked to the distribution of other GR partners, such as the NCoA-2 coactivator. Abnormal expression of SOX2, commonly observed in many tumors, may alter the biological action of GR and, probably, other SRs as well. Understanding this crosstalk may help to improve steroid hormone-based therapies in cancers with elevated SOX2 expression.
Collapse
|