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Jones M, Norman M, Tiet AM, Lee J, Lee MH. C. elegans Germline as Three Distinct Tumor Models. BIOLOGY 2024; 13:425. [PMID: 38927305 PMCID: PMC11200432 DOI: 10.3390/biology13060425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/04/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024]
Abstract
Tumor cells display abnormal growth and division, avoiding the natural process of cell death. These cells can be benign (non-cancerous growth) or malignant (cancerous growth). Over the past few decades, numerous in vitro or in vivo tumor models have been employed to understand the molecular mechanisms associated with tumorigenesis in diverse regards. However, our comprehension of how non-tumor cells transform into tumor cells at molecular and cellular levels remains incomplete. The nematode C. elegans has emerged as an excellent model organism for exploring various phenomena, including tumorigenesis. Although C. elegans does not naturally develop cancer, it serves as a valuable platform for identifying oncogenes and the underlying mechanisms within a live organism. In this review, we describe three distinct germline tumor models in C. elegans, highlighting their associated mechanisms and related regulators: (1) ectopic proliferation due to aberrant activation of GLP-1/Notch signaling, (2) meiotic entry failure resulting from the loss of GLD-1/STAR RNA-binding protein, (3) spermatogenic dedifferentiation caused by the loss of PUF-8/PUF RNA-binding protein. Each model requires the mutations of specific genes (glp-1, gld-1, and puf-8) and operates through distinct molecular mechanisms. Despite these differences in the origins of tumorigenesis, the internal regulatory networks within each tumor model display shared features. Given the conservation of many of the regulators implicated in C. elegans tumorigenesis, it is proposed that these unique models hold significant potential for enhancing our comprehension of the broader control mechanisms governing tumorigenesis.
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Affiliation(s)
- Mariah Jones
- Division of Hematology/Oncology, Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA; (M.J.); (M.N.)
| | - Mina Norman
- Division of Hematology/Oncology, Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA; (M.J.); (M.N.)
| | - Alex Minh Tiet
- Neuroscience Program, East Carolina University, Greenville, NC 27858, USA;
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Jiwoo Lee
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Myon Hee Lee
- Division of Hematology/Oncology, Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA; (M.J.); (M.N.)
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
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Feng L, Shi Z, Xie J, Ma B, Chen X. Enhancer of polycomb maintains germline activity and genome integrity in Drosophila testis. Cell Death Differ 2018; 25:1486-1502. [PMID: 29362481 DOI: 10.1038/s41418-017-0056-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 11/20/2017] [Accepted: 12/11/2017] [Indexed: 11/09/2022] Open
Abstract
Tissue homeostasis depends on the ability of tissue-specific adult stem cells to maintain a balance between proliferation and differentiation, as well as ensure DNA damage repair. Here, we use the Drosophila male germline stem cell system to study how a chromatin factor, enhancer of polycomb [E(Pc)], regulates the proliferation-to-differentiation (mitosis-to-meiosis) transition and DNA damage repair. We identified two critical targets of E(Pc). First, E(Pc) represses CycB transcription, likely through modulating H4 acetylation. Second, E(Pc) is required for accumulation of an important germline differentiation factor, Bag-of-marbles (Bam), through post-transcriptional regulation. When E(Pc) is downregulated, increased CycB and decreased Bam are both responsible for defective mitosis-to-meiosis transition in the germline. Moreover, DNA double-strand breaks (DSBs) accumulate upon germline inactivation of E(Pc) under both physiological condition and recovery from heat shock-induced endonuclease expression. Failure of robust DSB repair likely leads to germ cell loss. Finally, compromising the activity of Tip60, a histone acetyltransferase, leads to germline defects similar to E(Pc) loss-of-function, suggesting that E(Pc) acts cooperatively with Tip60. Together, our data demonstrate that E(Pc) has pleiotropic roles in maintaining male germline activity and genome integrity. Our findings will help elucidate the in vivo molecular mechanisms of E(Pc).
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Affiliation(s)
- Lijuan Feng
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.,Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY, 10065, USA
| | - Zhen Shi
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.,Geometry Technologies LLC, 6-302, 289 Bisheng Lane, Zhangjiang, Shanghai, 201204, China
| | - Jing Xie
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.,Clinical Research Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital; School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Binbin Ma
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.,Clinical Research Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital; School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.
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Singh SR, Liu Y, Kango-Singh M, Nevo E. Genetic, immunofluorescence labeling, and in situ hybridization techniques in identification of stem cells in male and female germline niches. Methods Mol Biol 2013; 1035:9-23. [PMID: 23959978 DOI: 10.1007/978-1-62703-508-8_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Stem cells have an enormous capacity of self-renewal, as well as the ability to differentiate into specialized cell types. Proper control of these two properties of stem cells is crucial for animal development, growth control, and reproduction. Germline stem cells (GSCs) are a self-renewing population of germ cells, which generate haploid gametes (sperms or oocyte) that transmit genetic information from generation to generation. In Drosophila testis and ovary, GSCs are anchored around the niche cells. The cap cells cluster in females and hub cells in males act as a niche to control GSC behavior. With highly sophisticated genetic techniques in Drosophila, tremendous progress has been made in understanding the interactions between stem cells and niches at cellular and molecular levels. Here, we provide details of genetic, immunofluorescence labeling, and in situ hybridization techniques in identification and characterization of stem cells in Drosophila male and female germline niches.
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Affiliation(s)
- Shree Ram Singh
- Mouse Cancer Genetics Program, National Cancer Institute, NIH, Frederick, MD, USA
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Wong C, Jones DL. Efficiency of spermatogonial dedifferentiation during aging. PLoS One 2012; 7:e33635. [PMID: 22442704 PMCID: PMC3307750 DOI: 10.1371/journal.pone.0033635] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 02/17/2012] [Indexed: 01/08/2023] Open
Abstract
Background Adult stem cells are critical for tissue homeostasis; therefore, the mechanisms utilized to maintain an adequate stem cell pool are important for the survival of an individual. In Drosophila, one mechanism utilized to replace lost germline stem cells (GSCs) is dedifferentiation of early progenitor cells. However, the average number of male GSCs decreases with age, suggesting that stem cell replacement may become compromised in older flies. Methodology/Principal Findings Using a temperature sensitive allelic combination of Stat92E to control dedifferentiation, we found that germline dedifferentiation is remarkably efficient in older males; somatic cells are also effectively replaced. Surprisingly, although the number of somatic cyst cells also declines with age, the proliferation rate of early somatic cells, including cyst stem cells (CySCs) increases. Conclusions These data indicate that defects in spermatogonial dedifferentiation are not likely to contribute significantly to an aging-related decline in GSCs. In addition, our findings highlight differences in the ways GSCs and CySCs age. Strategies to initiate or enhance the ability of endogenous, differentiating progenitor cells to replace lost stem cells could provide a powerful and novel strategy for maintaining tissue homeostasis and an alternative to tissue replacement therapy in older individuals.
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Affiliation(s)
- Chihunt Wong
- Laboratory of Genetics, The Salk Institute for Biological Studies, University of California San Diego, La Jolla, California, United States of America
- Division of Cell and Developmental Biology, Department of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - D. Leanne Jones
- Laboratory of Genetics, The Salk Institute for Biological Studies, University of California San Diego, La Jolla, California, United States of America
- Division of Cell and Developmental Biology, Department of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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