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Kozhukhar N, Alexeyev MF. Efficient Elimination of mtDNA from Mammalian Cells with 2',3'-Dideoxycytidine. DNA 2024; 4:201-211. [PMID: 39035221 PMCID: PMC11259038 DOI: 10.3390/dna4030013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
Mammalian cell lines devoid of mitochondrial DNA (mtDNA) are indispensable in studies aimed at elucidating the contribution of mtDNA to various cellular processes or interactions between nuclear and mitochondrial genomes. However, the repertoire of tools for generating such cells (also known as rho-0 or ρ0 cells) remains limited, and approaches remain time- and labor-intensive, ultimately limiting their availability. Ethidium bromide (EtBr), which is most commonly used to induce mtDNA loss in mammalian cells, is cytostatic and mutagenic as it affects both nuclear and mitochondrial genomes. Therefore, there is growing interest in new tools for generating ρ0 cell lines. Here, we examined the utility of 2',3'-dideoxycytidine (ddC, zalcitabine) alone or in combination with EtBr for generating ρ0 cell lines of mouse and human origin as well as inducing the ρ0 state in mouse/human somatic cell hybrids. We report that ddC is superior to EtBr in both immortalized mouse fibroblasts and human 143B cells. Also, unlike EtBr, ddC exhibits no cytostatic effects at the highest concentration tested (200 μM), making it more suitable for general use. We conclude that ddC is a promising new tool for generating mammalian ρ0 cell lines.
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Affiliation(s)
- Natalya Kozhukhar
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Mikhail F. Alexeyev
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, AL 36688, USA
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Mito T, Tani H, Suzuki M, Ishikawa K, Nakada K, Hayashi JI. Mito-mice∆ and mitochondrial DNA mutator mice as models of human osteoporosis caused not by aging but by hyperparathyroidism. Exp Anim 2018; 67:509-516. [PMID: 29973435 PMCID: PMC6219885 DOI: 10.1538/expanim.18-0060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mitochondrial DNA (mtDNA) mutator mice showing accelerated accumulation of mtDNA with
somatic mutations are potentially useful models of human aging, whereas mito-miceΔ showing
accelerated accumulation of mtDNA with a deletion mutation (ΔmtDNA) are potentially useful
models of mitochondrial diseases but not human aging, even though both models express an
age-associated decrease in mitochondrial respiration. Because osteoporosis is the only
premature aging phenotype observed in mtDNA mutator mice with the C57BL/6J nuclear genetic
background, our previous study precisely examined its expression spectra and reported that
both mtDNA mutator mice and mito-miceΔ, but not aged mice, developed decreased cortical
bone thickness. Moreover, decreased cortical bone thickness is usually not seen in aged
humans but is commonly seen in the patients with hyperparathyroidism caused by
oversecretion of parathyroid hormone (PTH). In the present study, we showed higher
concentrations of blood PTH in mtDNA mutator mice and mito-miceΔ than in aged mice. We
also found that both models developed decreased mitochondrial respiration in the duodenum
or renal tubules, which would lead to hypocalcemia, oversecretion of PTH, and ultimately
osteoporosis. Thus, mtDNA mutator mice and mito-miceΔ may be useful models of human
osteoporosis caused not by aging but by hyperparathyroidism.
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Affiliation(s)
- Takayuki Mito
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.,Japan Society for the Promotion of Science (JSPS), 8 Ichiban-cho, Chiyoda-ku, Tokyo 102-8472, Japan
| | - Haruna Tani
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Michiko Suzuki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Kaori Ishikawa
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Kazuto Nakada
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Jun-Ichi Hayashi
- University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
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The Oncojanus Paradigm of Respiratory Complex I. Genes (Basel) 2018; 9:genes9050243. [PMID: 29735924 PMCID: PMC5977183 DOI: 10.3390/genes9050243] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 04/09/2018] [Accepted: 05/03/2018] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial respiratory function is now recognized as a pivotal player in all the aspects of cancer biology, from tumorigenesis to aggressiveness and chemotherapy resistance. Among the enzymes that compose the respiratory chain, by contributing to energy production, redox equilibrium and oxidative stress, complex I assumes a central role. Complex I defects may arise from mutations in mitochondrial or nuclear DNA, in both structural genes or assembly factors, from alteration of the expression levels of its subunits, or from drug exposure. Since cancer cells have a high-energy demand and require macromolecules for proliferation, it is not surprising that severe complex I defects, caused either by mutations or treatment with specific inhibitors, prevent tumor progression, while contributing to resistance to certain chemotherapeutic agents. On the other hand, enhanced oxidative stress due to mild complex I dysfunction drives an opposite phenotype, as it stimulates cancer cell proliferation and invasiveness. We here review the current knowledge on the contribution of respiratory complex I to cancer biology, highlighting the double-edged role of this metabolic enzyme in tumor progression, metastasis formation, and response to chemotherapy.
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Bussard KM, Siracusa LD. Understanding Mitochondrial Polymorphisms in Cancer. Cancer Res 2017; 77:6051-6059. [PMID: 29097610 DOI: 10.1158/0008-5472.can-17-1939] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 07/25/2017] [Accepted: 09/13/2017] [Indexed: 11/16/2022]
Abstract
Alterations in mitochondrial DNA (mtDNA) were once thought to be predominantly innocuous to cell growth. Recent evidence suggests that mtDNA undergo naturally occurring alterations, including mutations and polymorphisms, which profoundly affect the cells in which they appear and contribute to a variety of diseases, including cardiovascular disease, diabetes, and cancer. Furthermore, interplay between mtDNA and nuclear DNA has been found in cancer cells, necessitating consideration of these complex interactions for future studies of cancer mutations and polymorphisms. In this issue of Cancer Research, Vivian and colleagues utilize a unique mouse model, called Mitochondrial Nuclear eXchange mice, that contain the nuclear DNA from one inbred mouse strain, and the mtDNA from a different inbred mouse strain to examine the genome-wide nuclear DNA methylation and gene expression patterns of brain tissue. Results demonstrated there were alterations in nuclear DNA expression and DNA methylation driven by mtDNA. These alterations may impact disease pathogenesis. In light of these results, in this review, we highlight alterations in mtDNA, with a specific focus on polymorphisms associated with cancer susceptibility and/or prognosis, mtDNA as cancer biomarkers, and considerations for investigating the role of mtDNA in cancer progression for future studies. Cancer Res; 77(22); 6051-9. ©2017 AACR.
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Affiliation(s)
- Karen M Bussard
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
| | - Linda D Siracusa
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania
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Garcia-Heredia JM, Carnero A. Decoding Warburg's hypothesis: tumor-related mutations in the mitochondrial respiratory chain. Oncotarget 2016; 6:41582-99. [PMID: 26462158 PMCID: PMC4747175 DOI: 10.18632/oncotarget.6057] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/23/2015] [Indexed: 01/13/2023] Open
Abstract
Otto Warburg observed that cancer cells derived their energy from aerobic glycolysis by converting glucose to lactate. This mechanism is in opposition to the higher energy requirements of cancer cells because oxidative phosphorylation (OxPhos) produces more ATP from glucose. Warburg hypothesized that this phenomenon occurs due to the malfunction of mitochondria in cancer cells. The rediscovery of Warburg's hypothesis coincided with the discovery of mitochondrial tumor suppressor genes that may conform to Warburg's hypothesis along with the demonstrated negative impact of HIF-1 on PDH activity and the activation of HIF-1 by oncogenic signals such as activated AKT. This work summarizes the alterations in mitochondrial respiratory chain proteins that have been identified and their involvement in cancer. Also discussed is the fact that most of the mitochondrial mutations have been found in homoplasmy, indicating a positive selection during tumor evolution, thereby supporting their causal role.
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Affiliation(s)
- Jose M Garcia-Heredia
- Instituto de Biomedicina de Sevilla (IBIS), HUVR/CSIC/Universidad de Sevilla, Sevilla, Spain.,Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Biología, Sevilla, Spain
| | - Amancio Carnero
- Instituto de Biomedicina de Sevilla (IBIS), HUVR/CSIC/Universidad de Sevilla, Sevilla, Spain
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Hayashi JI, Hashizume O, Ishikawa K, Shimizu A. Mutations in mitochondrial DNA regulate mitochondrial diseases and metastasis but do not regulate aging. Curr Opin Genet Dev 2016; 38:63-67. [PMID: 27078865 DOI: 10.1016/j.gde.2016.03.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/03/2016] [Accepted: 03/08/2016] [Indexed: 01/21/2023]
Abstract
The mitochondria theory of aging proposes that accumulation of mitochondrial DNA (mtDNA) with pathogenic mutations, and the resultant respiration defects, are responsible not only for mitochondrial diseases but also for aging and age-associated disorders, including tumor development. This theory is partly supported by results obtained from our transmitochondrial mice (mito-mice), which harbour mtDNA with mutations that are orthologous to those found in patients with mitochondrial diseases: mito-mice express disease phenotypes only when they express respiration defects caused by accumulation of mutated mtDNA. With regard to tumor development, specific mtDNA mutations that induce reactive oxygen species (ROS) enhance malignant transformation of lung carcinoma cells to cells with high metastatic potential. However, age-associated respiration defects in elderly human fibroblasts are due not to mtDNA mutations but to epigenetic regulation of nuclear-coded genes, as indicated by the fact that normal respiratory function is restored by reprogramming of elderly fibroblasts.
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Affiliation(s)
- Jun-Ichi Hayashi
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
| | - Osamu Hashizume
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Kaori Ishikawa
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Akinori Shimizu
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
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