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Guo S, Pei J, Wang X, Cao M, Xiong L, Kang Y, Ding Z, La Y, Chu M, Bao P, Guo X. Transcriptome Studies Reveal the N6-Methyladenosine Differences in Testis of Yaks at Juvenile and Sexual Maturity Stages. Animals (Basel) 2023; 13:2815. [PMID: 37760215 PMCID: PMC10525320 DOI: 10.3390/ani13182815] [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: 07/11/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
Studying the mechanism of spermatogenesis is key to exploring the reproductive characteristics of male yaks. Although N6-methyladenosine (m6A) RNA modification has been reported to regulate spermatogenesis and reproductive function in mammals, the molecular mechanism of m6A in yak testis development and spermatogenesis remains largely unknown. Therefore, we collected testicular tissue from juvenile and adult yaks and found that the m6A level significantly increased after sexual maturity in yaks. In MeRIP-seq, 1702 hypermethylated peaks and 724 hypomethylated peaks were identified. The hypermethylated differentially methylated RNAs (DMRs) (CIB2, AK1, FOXJ2, PKDREJ, SLC9A3, and TOPAZ1) mainly regulated spermatogenesis. Functional enrichment analysis showed that DMRs were significantly enriched in the adherens junction, gap junction, and Wnt, PI3K, and mTOR signaling pathways, regulating cell development, spermatogenesis, and testicular endocrine function. The functional analysis of differentially expressed genes showed that they were involved in the biological processes of mitosis, meiosis, and flagellated sperm motility during the sexual maturity of yak testis. We also screened the key regulatory factors of testis development and spermatogenesis by combined analysis, which included BRCA1, CREBBP, STAT3, and SMAD4. This study indexed the m6A characteristics of yak testicles at different developmental stages, providing basic data for further research of m6A modification regulating yak testicular development.
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Affiliation(s)
- Shaoke Guo
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Jie Pei
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Xingdong Wang
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Mengli Cao
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Lin Xiong
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Yandong Kang
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Ziqiang Ding
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Yongfu La
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Min Chu
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Pengjia Bao
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Xian Guo
- Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China; (S.G.); (J.P.); (X.W.); (M.C.); (L.X.); (Y.K.); (Z.D.); (Y.L.); (M.C.); (P.B.)
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
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Ghadirkhomi E, Angaji SA, Khosravi M, Mashayekhi MR. Association of Novel Single Nucleotide Polymorphisms of Genes Involved in Cell Functions with Male Infertility: A Study of Male Cases in Northwest Iran. J Reprod Infertil 2022; 22:258-266. [PMID: 34987987 PMCID: PMC8669412 DOI: 10.18502/jri.v22i4.7651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/29/2021] [Indexed: 11/24/2022] Open
Abstract
Background Infertility is a global health problem caused by various environmental and genetic factors. Male infertility accounts for 40-50% of all cases of infertility and approximately half of them are grouped as idiopathic with no definitive causes. Previous studies have suggested an association between some SNPs and infertility in men. In this study, an attempt was made to investigate the association of 7 different SNPs of 4 genes involved in common cell functions with male infertility. Methods MTHFR rs1801131 (T>G), MTHFR rs2274976 (G>A), FASLG rs80358238 (A>G), FASLG rs12079514 (A>C), GSTM1 rs1192077068 (G>A), BRCA2 rs4987117 (C>T), and BRCA2 rs11571833 (A>T) were genotyped in 120 infertile men with idiopathic azoospermia or severe oligospermia and 120 proven fertile controls using ARMS-PCR methods. Next, 30% of SNPs were regenotyped to confirm the results. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using SPSS statistical software to evaluate the strength of association. The p<0.05 were considered statistically significant. Results Statistical analysis revealed significant association between MTHFR rs-2274976 AA variant (OR: 10.00, CI: 3.203-31.225), FASLG rs12079514 AC variant (OR: 0.412, CI: 0.212-0.800), and BRCA2 rs11571833 TT variant OR: 6.233, CI: 3.211-12.101) with male infertility, but there was no significant difference between case and control groups in MTHFR rs1801131 (p= 0.111), GSTM1 rs1192077068 (p=0.272), BRCA2 rs4987117 (p=0.221), and FASLG rs80358238 (p=0.161). Conclusion Our findings suggested that some novel polymorphisms including MTHFR rs2274976, FASLG rs12079514, and BRCA2 rs11571833 might be the possible predisposing risk factors for male infertility in cases with idiopathic azoospermia.
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Affiliation(s)
- Elham Ghadirkhomi
- Department of Genetics, Faculty of Biological Sciences, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Seyed Abdolhamid Angaji
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Maryam Khosravi
- Biology Department, Faculty of Bio Sciences, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Mohammad Reza Mashayekhi
- Department of Genetics, Faculty of Biological Sciences, Tabriz Branch, Islamic Azad University, Tabriz, Iran
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Tarpey MD, Amorese AJ, LaFave ER, Minchew EC, Fisher-Wellman KH, McClung JM, Hvastkovs EG, Spangenburg EE. Skeletal Muscle Function Is Dependent Upon BRCA1 to Maintain Genomic Stability. Exerc Sport Sci Rev 2021; 49:267-273. [PMID: 34091499 PMCID: PMC8495729 DOI: 10.1249/jes.0000000000000265] [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] [Indexed: 11/21/2022]
Abstract
Breast Cancer gene 1 (BRCA1) is a large, multifunctional protein that regulates a variety of mechanisms in multiple different tissues. Our work established that Brca1 is expressed in skeletal muscle and localizes to the mitochondria and nucleus. Here, we propose BRCA1 expression is critical for the maintenance of force production and mitochondrial respiration in skeletal muscle.
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Affiliation(s)
- Michael D. Tarpey
- East Carolina University, Department of Physiology, Brody School of Medicine, Greenville, NC 27834
| | - Adam J. Amorese
- East Carolina University, Department of Physiology, Brody School of Medicine, Greenville, NC 27834
| | - Elizabeth R. LaFave
- East Carolina University, Department of Chemistry, 300 Science and Technology Bldg., Greenville, NC 27858
| | - Everett C. Minchew
- East Carolina University, Department of Physiology, Brody School of Medicine, Greenville, NC 27834
| | - Kelsey H. Fisher-Wellman
- East Carolina University, Department of Physiology, Brody School of Medicine, Greenville, NC 27834
- East Carolina Diabetes and Obesity Institute, 115 Heart Dr, East Carolina University, Greenville NC, 27834
| | - Joseph M. McClung
- East Carolina University, Department of Physiology, Brody School of Medicine, Greenville, NC 27834
- East Carolina Diabetes and Obesity Institute, 115 Heart Dr, East Carolina University, Greenville NC, 27834
| | - Eli G. Hvastkovs
- East Carolina University, Department of Chemistry, 300 Science and Technology Bldg., Greenville, NC 27858
| | - Espen E. Spangenburg
- East Carolina University, Department of Physiology, Brody School of Medicine, Greenville, NC 27834
- East Carolina Diabetes and Obesity Institute, 115 Heart Dr, East Carolina University, Greenville NC, 27834
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Tamhankar A, Tamhankar T. Hereditary Breast and Ovarian Cancer Syndrome (BRCA) Gene: Concept, Pathways, Therapeutics, and Future. Indian J Med Paediatr Oncol 2020. [DOI: 10.4103/ijmpo.ijmpo_172_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
AbstractHereditary breast and ovarian cancers are most commonly caused by mutations in BRCA1 and 2 genes. These are autosomal dominant mutations with high penetrance into subsequent generations. Affected individuals have deficiency in DNA repair mechanisms such as double strand DNA breaks (DSB) and non-homologous end joining (NHEJ). These tumors are peculiar due to early age of onset, typical histology such as triple negative breast cancers and high grade serous ovarian cancers and exquisite sensitivity to platinum analogues. These patients usually have better survival as compared to their wild type counterparts. Incidence of these mutations is rising due to better awareness about them amongst oncologists and patient population. Various genomic assays are available to detect germline and somatic BRCA mutations. Newer therapeutic frontiers like PARP inhibition have opened up due to better understanding of various mutations and their impact on subsequent pathways. Further studies are required to explore possibility of direct BRCA inhibition which may be useful in treatment of other solid organ cancers as well. This review focuses on understanding the pathophysiology of BRCA mutations, various pathways associated with the same, chemosensitivity patterns amongst affected cancer cells, targeted therapeutic opportunities and potential future developments in this field. We collected data from various published electronic records on google and have no conflicts of interest to be declared.
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Affiliation(s)
- Anup Tamhankar
- Deartment of Surgical Oncology, Deenanath Mangeshkar Hospital, Pune, Maharashtra, India
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Grive KJ, Hu Y, Shu E, Grimson A, Elemento O, Grenier JK, Cohen PE. Dynamic transcriptome profiles within spermatogonial and spermatocyte populations during postnatal testis maturation revealed by single-cell sequencing. PLoS Genet 2019; 15:e1007810. [PMID: 30893341 PMCID: PMC6443194 DOI: 10.1371/journal.pgen.1007810] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 04/01/2019] [Accepted: 02/18/2019] [Indexed: 12/22/2022] Open
Abstract
Spermatogenesis is the process by which male gametes are formed from a self-renewing population of spermatogonial stem cells (SSCs) residing in the testis. SSCs represent less than 1% of the total testicular cell population in adults, but must achieve a stable balance between self-renewal and differentiation. Once differentiation has occurred, the newly formed and highly proliferative spermatogonia must then enter the meiotic program in which DNA content is doubled, then halved twice to create haploid gametes. While much is known about the critical cellular processes that take place during the specialized cell division that is meiosis, much less is known about how the spermatocytes in the "first-wave" in juveniles compare to those that contribute to long-term, "steady-state" spermatogenesis in adults. Given the strictly-defined developmental process of spermatogenesis, this study explored the transcriptional profiles of developmental cell stages during testis maturation. Using a combination of comprehensive germ cell sampling with high-resolution, single-cell-mRNA-sequencing, we have generated a reference dataset of germ cell gene expression. We show that discrete developmental stages of spermatogenesis possess significant differences in the transcriptional profiles from neonates compared to juveniles and adults. Importantly, these gene expression dynamics are also reflected at the protein level in their respective cell types. We also show differential utilization of many biological pathways with age in both spermatogonia and spermatocytes, demonstrating significantly different underlying gene regulatory programs in these cell types over the course of testis development and spermatogenic waves. This dataset represents the first unbiased sampling of spermatogonia and spermatocytes during testis maturation, at high-resolution, single-cell depth. Not only does this analysis reveal previously unknown transcriptional dynamics of a highly transitional cell population, it has also begun to reveal critical differences in biological pathway utilization in developing spermatogonia and spermatocytes, including response to DNA damage and double-strand breaks.
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Affiliation(s)
- Kathryn J. Grive
- Center for Reproductive Genomics, Cornell University, Ithaca, NY, United States of America
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, United States of America
| | - Yang Hu
- Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY, United States of America
| | - Eileen Shu
- Center for Reproductive Genomics, Cornell University, Ithaca, NY, United States of America
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, United States of America
| | - Andrew Grimson
- Center for Reproductive Genomics, Cornell University, Ithaca, NY, United States of America
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, United States of America
| | - Olivier Elemento
- Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY, United States of America
| | - Jennifer K. Grenier
- Center for Reproductive Genomics, Cornell University, Ithaca, NY, United States of America
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, United States of America
| | - Paula E. Cohen
- Center for Reproductive Genomics, Cornell University, Ithaca, NY, United States of America
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, United States of America
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Genotypic and Phenotypic Variables Affect Meiotic Cell Cycle Progression, Tumor Ploidy, and Cancer-Associated Mortality in a brca2-Mutant Zebrafish Model. JOURNAL OF ONCOLOGY 2019; 2019:9218251. [PMID: 30930946 PMCID: PMC6413366 DOI: 10.1155/2019/9218251] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/10/2019] [Accepted: 01/28/2019] [Indexed: 11/17/2022]
Abstract
Successful cell replication requires both cell cycle completion and accurate chromosomal segregation. The tumor suppressor BRCA2 is positioned to influence both of these outcomes, and thereby influence genomic integrity, during meiotic and mitotic cell cycles. Accordingly, mutations in BRCA2 induce chromosomal abnormalities and disrupt cell cycle progression in both germ cells and somatic cells. Despite these findings, aneuploidy is not more prevalent in BRCA2-associated versus non-BRCA2-associated human cancers. More puzzlingly, diploidy in BRCA2-associated cancers is a negative prognostic factor, unlike non-BRCA2-associated cancers and many other human cancers. We used a brca2-mutant/tp53-mutant cancer-prone zebrafish model to explore the impact of BRCA2 mutation on cell cycle progression, ploidy, and cancer-associated mortality by performing DNA content/cell cycle analysis on zebrafish germ cells, somatic cells, and cancer cells. First, we determined that combined brca2/tp53 mutations uniquely disrupt meiotic progression. Second, we determined that sex significantly influences ploidy outcome in zebrafish cancers. Third, we determined that brca2 mutation and female sex each significantly reduce survival time in cancer-bearing zebrafish. Finally, we provide evidence to support a link between BRCA2 mutation, tumor diploidy, and poor survival outcome. These outcomes underscore the utility of this model for studying BRCA2-associated genomic aberrations in normal and cancer cells.
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Martin JH, Aitken RJ, Bromfield EG, Cafe SL, Sutherland JM, Frost ER, Nixon B, Lord T. Investigation into the presence and functional significance of proinsulin C-peptide in the female germline†. Biol Reprod 2019; 100:1275-1289. [DOI: 10.1093/biolre/ioz008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 12/10/2018] [Accepted: 01/28/2019] [Indexed: 12/26/2022] Open
Affiliation(s)
- Jacinta H Martin
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, The Hunter Medical Research Institute, New Lambton Heights and the University of Newcastle, Callaghan, Newcastle, Australia
| | - R John Aitken
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, The Hunter Medical Research Institute, New Lambton Heights and the University of Newcastle, Callaghan, Newcastle, Australia
| | - Elizabeth G Bromfield
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, The Hunter Medical Research Institute, New Lambton Heights and the University of Newcastle, Callaghan, Newcastle, Australia
| | - Shenae L Cafe
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, The Hunter Medical Research Institute, New Lambton Heights and the University of Newcastle, Callaghan, Newcastle, Australia
| | - Jessie M Sutherland
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, The Hunter Medical Research Institute, New Lambton Heights and the University of Newcastle, Callaghan, Newcastle, Australia
| | - Emily R Frost
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, The Hunter Medical Research Institute, New Lambton Heights and the University of Newcastle, Callaghan, Newcastle, Australia
| | - Brett Nixon
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, The Hunter Medical Research Institute, New Lambton Heights and the University of Newcastle, Callaghan, Newcastle, Australia
| | - Tessa Lord
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, The Hunter Medical Research Institute, New Lambton Heights and the University of Newcastle, Callaghan, Newcastle, Australia
- School of Molecular Biosciences, Centre for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
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Magalhães J, Ascensão A, Padrão AI, Aleixo IM, Santos-Alves E, Rocha-Rodrigues S, Ferreira A, Korrodi-Gregório L, Vitorino R, Ferreira R, Fardilha M. Can exercise training counteract doxorubicin-induced oxidative damage of testis proteome? Toxicol Lett 2017; 280:57-69. [PMID: 28818578 DOI: 10.1016/j.toxlet.2017.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 07/02/2017] [Accepted: 08/10/2017] [Indexed: 02/04/2023]
Abstract
The use of the chemotherapeutic drug doxorubicin (DOX) is limited by its toxicity in several organs such as testes. So, we analyzed the effect of endurance treadmill exercise training (EX) performed before sub-chronic DOX treatment on sperm count and motility, testes markers of oxidative damage and apoptosis. Tissue profiling of proteins more susceptible to oxidation was made to identify the molecular pathways regulated by oxidative modifications, as nitration and carbonylation. Twenty-four adult male rats were divided into four groups (n=6/group): sedentary saline (SED+SAL), sedentary sub-chronically injected with DOX (2mg-kg-1 per week, during 7 weeks; SED+DOX), 12 weeks trained saline (EX+SAL) and trained treated with DOX (EX+DOX). DOX treatment started 5 weeks after the beginning of the exercise program. Testes caspase-3, -8 and -9, as well as aconitase activities, the content of malondialdehyde (MDA), sulfhydryl groups (-SH), carbonyl and nitrotyrosine derivatives were determined. Modified proteins were identified by 2D-Western blot followed by MALDI-TOF/TOF mass spectrometry, and bioinformatic analysis was performed to assess the biological processes regulated by these chemical modifications. The decreased sperm motility induced by DOX was not modified by exercise. Significant increases in MDA content in SED+DOX and in caspase-3 and -9 activities in EX+DOX were found. Despite no significant differences in the levels of carbonylated and nitrated proteins, exercise modulated testis proteome susceptibility to oxidation in DOX-treated group, with less modified proteins identified. Zinc finger Ran-binding domain-containing protein 2 (ZRAB2) and AN1-type zinc finger protein 3 (ZFAN3) were among the proteins found oxidativelly modified. Although no marked alterations in testes oxidative damage were noticed, proteomic analysis of oxidativelly modified proteins highlighted the protective role of exercise against oxidative damage of some proteins involved in metabolism and stress response against DOX.
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Affiliation(s)
- José Magalhães
- Research Centre in Physical Activity Health and Leisure (CIAFEL), Faculty of Sports, University of Porto, R. Dr. Plácido da Costa 91, Porto, Portugal
| | - António Ascensão
- Research Centre in Physical Activity Health and Leisure (CIAFEL), Faculty of Sports, University of Porto, R. Dr. Plácido da Costa 91, Porto, Portugal
| | - Ana I Padrão
- Research Centre in Physical Activity Health and Leisure (CIAFEL), Faculty of Sports, University of Porto, R. Dr. Plácido da Costa 91, Porto, Portugal; QOPNA, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Inês M Aleixo
- Research Centre in Physical Activity Health and Leisure (CIAFEL), Faculty of Sports, University of Porto, R. Dr. Plácido da Costa 91, Porto, Portugal
| | - Estela Santos-Alves
- Research Centre in Physical Activity Health and Leisure (CIAFEL), Faculty of Sports, University of Porto, R. Dr. Plácido da Costa 91, Porto, Portugal
| | - Sílvia Rocha-Rodrigues
- Research Centre in Physical Activity Health and Leisure (CIAFEL), Faculty of Sports, University of Porto, R. Dr. Plácido da Costa 91, Porto, Portugal
| | - André Ferreira
- Laboratory of Signal Transduction, Institute for Research in Biomedicine, Medical Sciences Department, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Luis Korrodi-Gregório
- Laboratory of Signal Transduction, Institute for Research in Biomedicine, Medical Sciences Department, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Rui Vitorino
- Laboratory of Signal Transduction, Institute for Research in Biomedicine, Medical Sciences Department, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal; Unidade de Investigação Cardiovascular, Departamento de Cirurgia e Fisiologia, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, Porto, Portugal.
| | - Rita Ferreira
- QOPNA, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Margarida Fardilha
- Laboratory of Signal Transduction, Institute for Research in Biomedicine, Medical Sciences Department, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
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Do TV, Hirst J, Hyter S, Roby KF, Godwin AK. Aurora A kinase regulates non-homologous end-joining and poly(ADP-ribose) polymerase function in ovarian carcinoma cells. Oncotarget 2017; 8:50376-50392. [PMID: 28881569 PMCID: PMC5584138 DOI: 10.18632/oncotarget.18970] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/16/2017] [Indexed: 01/08/2023] Open
Abstract
Ovarian cancer is usually diagnosed at late stages when cancer has spread beyond the ovary and patients ultimately succumb to the development of drug-resistant disease. There is an urgent and unmet need to develop therapeutic strategies that effectively treat ovarian cancer and this requires a better understanding of signaling pathways important for ovarian cancer progression. Aurora A kinase (AURKA) plays an important role in ovarian cancer progression by mediating mitosis and chromosomal instability. In the current study, we investigated the role of AURKA in regulating the DNA damage response and DNA repair in ovarian carcinoma cells. We discovered that AURKA modulated the expression and activity of PARP, a crucial mediator of DNA repair that is a target of therapeutic interest for the treatment of ovarian and other cancers. Further, specific inhibition of AURKA activity with the small molecule inhibitor, alisertib, stimulated the non-homologous end-joining (NHEJ) repair pathway by elevating DNA-PKcs activity, a catalytic subunit required for double-strand break (DSB) repair, as well as decreased the expression of PARP and BRCA1/2, which are required for high-fidelity homologous recombination-based DNA repair. Further, AURKA inhibition stimulates error-prone NHEJ repair of DNA double-strand breaks with incompatible ends. Consistent with in vitro findings, alisertib treatment increased phosphorylated DNA-PKcs(pDNA-PKcsT2609) and decreased PARP levels in vivo. Collectively, these results reveal new non-mitotic functions for AURKA in the regulation of DNA repair, which may inform of new therapeutic targets and strategies for treating ovarian cancer.
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Affiliation(s)
- Thuy-Vy Do
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Jeff Hirst
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Stephen Hyter
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Katherine F. Roby
- Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
- University of Kansas Cancer Center, Kansas City, KS, USA
| | - Andrew K. Godwin
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, USA
- University of Kansas Cancer Center, Kansas City, KS, USA
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MicroRNA-206 is differentially expressed in Brca1-deficient mice and regulates epithelial and stromal cell compartments of the mouse mammary gland. Oncogenesis 2016; 5:e218. [PMID: 27043663 PMCID: PMC4848838 DOI: 10.1038/oncsis.2016.27] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 01/28/2016] [Accepted: 02/10/2016] [Indexed: 12/14/2022] Open
Abstract
Depletion of Brca1 leads to defects in mouse mammary gland development and mammary tumors in humans and mice. To explore the role of microRNAs (miRNAs) in this process, we examined the mammary glands of MMTV-Cre Brca1Co/Co mice for differential miRNA expression using a candidate approach. Several miRNAs were differentially expressed in mammary tissue at day 1 of lactation and in mammary epithelial cell lines in which Brca1 messenger RNA (mRNA) levels have been reduced. Functional studies revealed that several of these miRNAs regulate mammary epithelial cell function in vitro, including miR-206. Creation and analysis of MMTV-miR-206 transgenic mice showed no effect on lactational mammary development and no tumors, but indicates a role in mammary tissue remodeling in mature mice, potentially involving Igf-1 and Sfrp1. These results indicate the potential of miRNAs to mediate the consequences of Brca1 loss and suggest a novel function for miR-206.
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Mittal V, El Rayes T, Narula N, McGraw TE, Altorki NK, Barcellos-Hoff MH. The Microenvironment of Lung Cancer and Therapeutic Implications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 890:75-110. [PMID: 26703800 DOI: 10.1007/978-3-319-24932-2_5] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The tumor microenvironment (TME) represents a milieu that enables tumor cells to acquire the hallmarks of cancer. The TME is heterogeneous in composition and consists of cellular components, growth factors, proteases, and extracellular matrix. Concerted interactions between genetically altered tumor cells and genetically stable intratumoral stromal cells result in an "activated/reprogramed" stroma that promotes carcinogenesis by contributing to inflammation, immune suppression, therapeutic resistance, and generating premetastatic niches that support the initiation and establishment of distant metastasis. The lungs present a unique milieu in which tumors progress in collusion with the TME, as evidenced by regions of aberrant angiogenesis, acidosis and hypoxia. Inflammation plays an important role in the pathogenesis of lung cancer, and pulmonary disorders in lung cancer patients such as chronic obstructive pulmonary disease (COPD) and emphysema, constitute comorbid conditions and are independent risk factors for lung cancer. The TME also contributes to immune suppression, induces epithelial-to-mesenchymal transition (EMT) and diminishes efficacy of chemotherapies. Thus, the TME has begun to emerge as the "Achilles heel" of the disease, and constitutes an attractive target for anti-cancer therapy. Drugs targeting the components of the TME are making their way into clinical trials. Here, we will focus on recent advances and emerging concepts regarding the intriguing role of the TME in lung cancer progression, and discuss future directions in the context of novel diagnostic and therapeutic opportunities.
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MESH Headings
- Antibodies, Monoclonal/therapeutic use
- Antineoplastic Agents/therapeutic use
- Carcinogenesis/drug effects
- Carcinogenesis/genetics
- Carcinogenesis/metabolism
- Carcinogenesis/pathology
- Cell Communication/drug effects
- Drug Resistance, Neoplasm/genetics
- Epithelial-Mesenchymal Transition/drug effects
- Epithelial-Mesenchymal Transition/genetics
- Gene Expression Regulation, Neoplastic
- Humans
- Lung Diseases, Obstructive/complications
- Lung Diseases, Obstructive/drug therapy
- Lung Diseases, Obstructive/genetics
- Lung Diseases, Obstructive/metabolism
- Lung Neoplasms/complications
- Lung Neoplasms/drug therapy
- Lung Neoplasms/genetics
- Lung Neoplasms/metabolism
- Mesenchymal Stem Cells/drug effects
- Mesenchymal Stem Cells/metabolism
- Mesenchymal Stem Cells/pathology
- Neoplastic Stem Cells/drug effects
- Neoplastic Stem Cells/metabolism
- Neoplastic Stem Cells/pathology
- Neovascularization, Pathologic/genetics
- Neovascularization, Pathologic/metabolism
- Neovascularization, Pathologic/pathology
- Neovascularization, Pathologic/prevention & control
- Pulmonary Emphysema/complications
- Pulmonary Emphysema/drug therapy
- Pulmonary Emphysema/genetics
- Pulmonary Emphysema/metabolism
- Tumor Microenvironment/drug effects
- Tumor Microenvironment/genetics
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Affiliation(s)
- Vivek Mittal
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA.
- Department of Cardiothoracic Surgery, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA.
- Neuberger Berman Lung Cancer Research Center, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA.
| | - Tina El Rayes
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
- Department of Cardiothoracic Surgery, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
- Neuberger Berman Lung Cancer Research Center, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
- Weill Cornell Graduate School of Medical Sciences, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
| | - Navneet Narula
- Department of Pathology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
| | - Timothy E McGraw
- Department of Cardiothoracic Surgery, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
- Neuberger Berman Lung Cancer Research Center, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
- Department of Biochemistry, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
| | - Nasser K Altorki
- Department of Cardiothoracic Surgery, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
- Neuberger Berman Lung Cancer Research Center, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10065, USA
| | - Mary Helen Barcellos-Hoff
- Department of Radiation Oncology, New York University School of Medicine, 566 First Avenue, New York, NY, 10016, USA.
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Ortega FJ, Moreno-Navarrete JM, Mayas D, García-Santos E, Gómez-Serrano M, Rodriguez-Hermosa JI, Ruiz B, Ricart W, Tinahones FJ, Frühbeck G, Peral B, Fernández-Real JM. Breast cancer 1 (BrCa1) may be behind decreased lipogenesis in adipose tissue from obese subjects. PLoS One 2012; 7:e33233. [PMID: 22666314 PMCID: PMC3364252 DOI: 10.1371/journal.pone.0033233] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 02/06/2012] [Indexed: 01/10/2023] Open
Abstract
CONTEXT Expression and activity of the main lipogenic enzymes is paradoxically decreased in obesity, but the mechanisms behind these findings are poorly known. Breast Cancer 1 (BrCa1) interacts with acetyl-CoA carboxylase (ACC) reducing the rate of fatty acid biosynthesis. In this study, we aimed to evaluate BrCa1 in human adipose tissue according to obesity and insulin resistance, and in vitro cultured adipocytes. RESEARCH DESIGN AND METHODS BrCa1 gene expression, total and phosphorylated (P-) BrCa1, and ACC were analyzed in adipose tissue samples obtained from a total sample of 133 subjects. BrCa1 expression was also evaluated during in vitro differentiation of human adipocytes and 3T3-L1 cells. RESULTS BrCa1 gene expression was significantly up-regulated in both omental (OM; 1.36-fold, p = 0.002) and subcutaneous (SC; 1.49-fold, p = 0.001) adipose tissue from obese subjects. In parallel with increased BrCa1 mRNA, P-ACC was also up-regulated in SC (p = 0.007) as well as in OM (p = 0.010) fat from obese subjects. Consistent with its role limiting fatty acid biosynthesis, both BrCa1 mRNA (3.5-fold, p<0.0001) and protein (1.2-fold, p = 0.001) were increased in pre-adipocytes, and decreased during in vitro adipogenesis, while P-ACC decreased during differentiation of human adipocytes (p = 0.005) allowing lipid biosynthesis. Interestingly, BrCa1 gene expression in mature adipocytes was restored by inflammatory stimuli (macrophage conditioned medium), whereas lipogenic genes significantly decreased. CONCLUSIONS The specular findings of BrCa1 and lipogenic enzymes in adipose tissue and adipocytes reported here suggest that BrCa1 might help to control fatty acid biosynthesis in adipocytes and adipose tissue from obese subjects.
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Affiliation(s)
- Francisco J. Ortega
- Service of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona, CIBER de la Fisiopatología de la Obesidad y Nutrición, and Instituto de Salud Carlos III, Girona, Spain
| | - José M. Moreno-Navarrete
- Service of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona, CIBER de la Fisiopatología de la Obesidad y Nutrición, and Instituto de Salud Carlos III, Girona, Spain
| | - Dolores Mayas
- Service of Endocrinology and Nutrition, Hospital Clínico Universitario Virgen de Victoria de Malaga, CIBER de la Fisiopatología de la Obesidad y Nutrición, and Instituto de Salud Carlos III, Málaga, Spain
| | - Eva García-Santos
- Department of Endocrinology, Physiopathology and Nervous System, Instituto de Investigaciones Biomédicas ‘Alberto Sols’, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - María Gómez-Serrano
- Department of Endocrinology, Physiopathology and Nervous System, Instituto de Investigaciones Biomédicas ‘Alberto Sols’, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Bartomeu Ruiz
- Department of Surgery, Institut d'Investigació Biomèdica de Girona, Girona, Spain
| | - Wifredo Ricart
- Service of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona, CIBER de la Fisiopatología de la Obesidad y Nutrición, and Instituto de Salud Carlos III, Girona, Spain
| | - Francisco J. Tinahones
- Service of Endocrinology and Nutrition, Hospital Clínico Universitario Virgen de Victoria de Malaga, CIBER de la Fisiopatología de la Obesidad y Nutrición, and Instituto de Salud Carlos III, Málaga, Spain
| | - Gema Frühbeck
- Department of Endocrinology, Clínica Universidad de Navarra, CIBER de la Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Navarra, Spain
| | - Belen Peral
- Department of Endocrinology, Physiopathology and Nervous System, Instituto de Investigaciones Biomédicas ‘Alberto Sols’, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - José M. Fernández-Real
- Service of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona, CIBER de la Fisiopatología de la Obesidad y Nutrición, and Instituto de Salud Carlos III, Girona, Spain
- * E-mail:
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Trapp O, Seeliger K, Puchta H. Homologs of breast cancer genes in plants. FRONTIERS IN PLANT SCIENCE 2011; 2:19. [PMID: 22629260 PMCID: PMC3355568 DOI: 10.3389/fpls.2011.00019] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 06/02/2011] [Indexed: 05/22/2023]
Abstract
Since the initial discovery of genes involved in hereditary breast cancer in humans, a vast wealth of information has been published. Breast cancer proteins were shown to work as tumor suppressors primarily through their involvement in DNA-damage repair. Surprisingly, homologs of these genes can be found in plant genomes, as well. Here, we want to give an overview of the identification and characterization of the biological roles of these proteins, in plants. In addition to the conservation of their function in DNA repair, new plant-specific characteristics have been revealed. BRCA1 is required for the efficient repair of double strand breaks (DSB) by homologous recombination in somatic cells of the model plant Arabidopsis thaliana. Bioinformatic analysis indicates that, whereas most homologs of key components of the different mammalian BRCA1 complexes are present in plant genomes, homologs of most factors involved in the recruitment of BRCA1 to the DSB cannot be identified. Thus, it is not clear at the moment whether differences exist between plants and animals at this important step. The most conserved region of BRCA1 and BARD1 homologs in plants is a PHD domain which is absent in mammals and which, in AtBARD1, might be involved in the transcriptional regulation of plant development. The presence of a plant-specific domain prompted us to reevaluate the current model for the evolution of BRCA1 homologs and to suggest a new hypothesis, in which we postulate that plant BRCA1 and BARD1 have one common predecessor that gained a PHD domain before duplication. Furthermore, work in Arabidopsis demonstrates that - as in animals - BRCA2 homologs are important for meiotic DNA recombination. Surprisingly, recent research has revealed that AtBRCA2 also has an important role in systemic acquired resistance. In Arabidopsis, BRCA2 is involved in the transcriptional regulation of pathogenesis-related (PR) genes via its interaction with the strand exchange protein RAD51.
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Affiliation(s)
- Oliver Trapp
- Botanical Institute II, Karlsruhe Institute of TechnologyKarlsruhe, Germany
| | - Katharina Seeliger
- Botanical Institute II, Karlsruhe Institute of TechnologyKarlsruhe, Germany
| | - Holger Puchta
- Botanical Institute II, Karlsruhe Institute of TechnologyKarlsruhe, Germany
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14
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Di LJ, Fernandez AG, De Siervi A, Longo DL, Gardner K. Transcriptional regulation of BRCA1 expression by a metabolic switch. Nat Struct Mol Biol 2010; 17:1406-13. [PMID: 21102443 PMCID: PMC3460552 DOI: 10.1038/nsmb.1941] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 09/16/2010] [Indexed: 12/29/2022]
Abstract
Though the linkages between germline mutations of BRCA1 and hereditary breast cancer are well known, recent evidence suggests that altered BRCA1 transcription may also contribute to sporadic forms of breast cancer. Here we show that BRCA1 expression is controlled by a dynamic equilibrium between transcriptional coactivators and co-repressors that govern histone acetylation and DNA accessibility at the BRCA1 promoter. Eviction of the transcriptional co-repressor and metabolic sensor, C terminal-binding protein (CtBP), has a central role in this regulation. Loss of CtBP from the BRCA1 promoter through estrogen induction, depletion by RNA interference or increased NAD+/NADH ratio leads to HDAC1 dismissal, elevated histone acetylation and increased BRCA1 transcription. The active control of chromatin marks, DNA accessibility and gene expression at the BRCA1 promoter by this 'metabolic switch' provides an important molecular link between caloric intake and tumor suppressor expression in mammary cells.
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Affiliation(s)
- Li-Jun Di
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, Maryland, USA
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15
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Swisher EM, Gonzalez RM, Taniguchi T, Garcia RL, Walsh T, Goff BA, Welcsh P. Methylation and protein expression of DNA repair genes: association with chemotherapy exposure and survival in sporadic ovarian and peritoneal carcinomas. Mol Cancer 2009; 8:48. [PMID: 19602291 PMCID: PMC2719582 DOI: 10.1186/1476-4598-8-48] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Accepted: 07/14/2009] [Indexed: 12/25/2022] Open
Abstract
Background DNA repair genes critically regulate the cellular response to chemotherapy and epigenetic regulation of these genes may be influenced by chemotherapy exposure. Restoration of BRCA1 and BRCA2 mediates resistance to platinum chemotherapy in recurrent BRCA1 and BRCA2 mutated hereditary ovarian carcinomas. We evaluated BRCA1, BRCA2, and MLH1 protein expression in 115 sporadic primary ovarian carcinomas, of which 31 had paired recurrent neoplasms collected after chemotherapy. Additionally, we assessed whether promoter methylation of BRCA1, MLH1 or FANCF influenced response to chemotherapy or explained alterations in protein expression after chemotherapy exposure. Results Of 115 primary sporadic ovarian carcinomas, 39 (34%) had low BRCA1 protein and 49 (42%) had low BRCA2 expression. BRCA1 and BRCA2 protein expression were highly concordant (p < 0.0001). MLH1 protein loss occurred in 28/115 (24%) primary neoplasms. BRCA1 protein loss in primary neoplasms was associated with better survival (p = 0.02 Log Rank test) and remained significant after accounting for either stage or age in a multivariate model (p = 0.04, Cox proportional hazards). In paired specimens, BRCA1 protein expression increased in 13/21 (62%) and BRCA2 protein expression increased in 15/21 (71%) of recurrent carcinomas with low or intermediate protein in the paired primary. In contrast MLH1 expression was rarely decreased in recurrent carcinomas (1/33, 3%). Similar frequencies of MLH1, BRCA1, and FANCF promoter methylation occurred in primary carcinomas without previous chemotherapy, after neoadjuvant chemotherapy, or in recurrent neoplasms. Conclusion Low BRCA1 expression in primary sporadic ovarian carcinoma is associated with prolonged survival. Recurrent ovarian carcinomas commonly have increased BRCA1 and/or BRCA2 protein expression post chemotherapy exposure which could mediate resistance to platinum based therapies. However, alterations in expression of these proteins after chemotherapy are not commonly mediated by promoter methylation, and other regulatory mechanisms are likely to contribute to these alterations.
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Affiliation(s)
- Elizabeth M Swisher
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle, WA 98195, USA.
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Salmand PA, Jungas T, Fernandez M, Conter A, Christians ES. Mouse Heat-Shock Factor 1 (HSF1) Is Involved in Testicular Response to Genotoxic Stress Induced by Doxorubicin1. Biol Reprod 2008; 79:1092-101. [PMID: 18703420 DOI: 10.1095/biolreprod.108.070334] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Pierre A Salmand
- Université Toulouse 3, Unité Mixte de Recherche 5547 (UMR 5547), Centre National pour la Recherche Scientifique (CNRS)-Université Paul Sabatier (UPS), 31062 Toulouse, France
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17
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Les souris génétiquement modifiées au service de la reproduction. ACTA ACUST UNITED AC 2008; 36:1224-9. [DOI: 10.1016/j.gyobfe.2008.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 10/03/2008] [Indexed: 11/22/2022]
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18
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Antonova L, Mueller CR. Hydrocortisone down-regulates the tumor suppressor gene BRCA1 in mammary cells: a possible molecular link between stress and breast cancer. Genes Chromosomes Cancer 2008; 47:341-52. [PMID: 18196591 DOI: 10.1002/gcc.20538] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Psychological stress has been correlated with breast cancer development in numerous epidemiological studies. However, physiological and molecular models which may account for this association are not readily available. We have found that the stress hormone hydrocortisone (cortisol) down-regulates the expression of the breast cancer susceptibility gene BRCA1 in the nonmalignant mouse mammary cell line EPH4. This effect is concentration-dependent, is reliant on the continuous presence of hydrocortisone, and is not affected by the addition of lactogenic hormones, or growth conditions. Hydrocortisone was also found to negate a known positive effect of estrogen on BRCA1 expression and, therefore, may interfere with estrogen-related signaling in mammary epithelial cells. The repressive effect of hydrocortisone is diminished or lost in the mouse mammary lines HC-11 and SP1, respectively, suggesting regulation of the BRCA1 may differ between lines. We have uncovered two promoter regulatory sites, which are involved in BRCA1 regulation by hydrocortisone, namely the RIBS and UP regulatory elements. Binding of the transcription factor GABP to both sites is lost upon hydrocortisone addition, though the levels of these factors are not altered by hydrocortisone treatment. Because BRCA1 activity is important for a number of intracellular pathways involved in prevention of tumorigenesis, its observed down-regulation may represent a novel molecular mechanism for cortisol's involvement in breast cancer development.
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Affiliation(s)
- Lilia Antonova
- Queen's Cancer Research Institute, Queen's University, Kingston, ON, Canada
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Hoshino A, Yee CJ, Campbell M, Woltjer RL, Townsend RL, van der Meer R, Shyr Y, Holt JT, Moses HL, Jensen RA. Effects of BRCA1 transgene expression on murine mammary gland development and mutagen-induced mammary neoplasia. Int J Biol Sci 2007; 3:281-91. [PMID: 17505536 PMCID: PMC1865089 DOI: 10.7150/ijbs.3.281] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Accepted: 04/24/2007] [Indexed: 01/19/2023] Open
Abstract
To characterize the role of BRCA1 in mammary gland development and tumor suppression, a transgenic mouse model of BRCA1 overexpression was developed. Using the mouse mammary tumor virus (MMTV) promoter/enhancer, transgenic mice expressing human BRCA1 or select mutant controls were generated. Transgenic animals examined during adolescence were shown to express the human transgene in their mammary glands. The mammary glands of 13-week-old virgin homozygous MMTV-BRCA1 mice presented the morphology of moderately increased lobulo-alveolar development. The mammary ductal trees of both hemizygous and homozygous MMTV-BRCA1t340 were similar to those of control non-transgenic littermates. Interestingly, both hemi- and homozygous mice expressing a splice variant of BRCA1 lacking the N-terminal RING finger domain (MMTV-BRCA1sv) exhibited marked mammary lobulo-alveolar development, particularly terminal end bud proliferation. Morphometric analyses of mammary gland whole mount preparations were used to measure epithelial staining indices of ~35% for homozygous MMTV-BRCA1 mice and ~60% for both hemizygous and homozygous MMTV-BRCA1sv mice versus ~25% for non-transgenic mice. Homozygous MMTV-BRCA1 mice showed delayed development of tumors when challenged with 7,12 dimethylbenzanthracene (DMBA), relative to non-transgenic and homozygous BRCA1t340 expressing mice. In contrast, homozygous MMTV-BRCA1sv transgenic animals were sensitized to DMBA treatment and exhibited a very rapid onset of mammary tumor development and accelerated mortality. MMTV-BRCA1 effects on mortality were restricted to DMBA-induced tumors of the mammary gland. These results demonstrate in vivo roles for BRCA1 in both mammary gland development and in tumor suppression against mutagen-induced mammary gland neoplasia.
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MESH Headings
- 9,10-Dimethyl-1,2-benzanthracene/toxicity
- Animals
- BRCA1 Protein/physiology
- Carcinogens/toxicity
- Female
- Gene Expression
- Gene Transfer Techniques
- Genes, BRCA1
- Mammary Glands, Animal/anatomy & histology
- Mammary Glands, Animal/growth & development
- Mammary Neoplasms, Experimental/chemically induced
- Mammary Neoplasms, Experimental/genetics
- Mammary Tumor Virus, Mouse
- Mice
- Mice, Inbred Strains
- Mice, Transgenic
- Pregnancy
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Affiliation(s)
- Arichika Hoshino
- 1. Departments of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Cindy J. Yee
- 1. Departments of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Mel Campbell
- 1. Departments of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- 4. Kansas Masonic Cancer Research Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160-7312, USA
| | - Randall L. Woltjer
- 1. Departments of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Rebecca L. Townsend
- 2. Departments of Cell Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Riet van der Meer
- 1. Departments of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yu Shyr
- 3. Departments of Biostatistics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jeffrey T. Holt
- 1. Departments of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- 2. Departments of Cell Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Harold L. Moses
- 1. Departments of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- 2. Departments of Cell Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Roy A. Jensen
- 1. Departments of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- 2. Departments of Cell Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- 4. Kansas Masonic Cancer Research Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160-7312, USA
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Abstract
Mutation has traditionally been considered a random process, but this paradigm is challenged by recent evidence of divergence rate heterogeneity in different genomic regions. One facet of mutation rate variation is the propensity for genetic change to correlate with the number of germ cell divisions, reflecting the replication-dependent origin of many mutations. Haldane was the first to connect this association of replication and mutation to the difference in the number of cell divisions in oogenesis (low) and spermatogenesis (usually high), and the resulting sex difference in the rate of mutation. The concept of male-biased mutation has been thoroughly analysed in recent years using an evolutionary approach, in which sequence divergence of autosomes and/or sex chromosomes are compared to allow inference about the relative contribution of mothers and fathers in the accumulation of mutations. For instance, assuming that a neutral sequence is analysed, that rate heterogeneity owing to other factors is cancelled out by the investigation of many loci and that the effect of ancestral polymorphism is properly taken into account, the male-to-female mutation rate ratio, alpham, can be solved from the observed difference in rate of X and Y chromosome divergence. The male mutation bias is positively correlated with the relative excess of cell divisions in the male compared to the female germ line, as evidenced by a generation time effect: in mammals, alpham is estimated at approximately 4-6 in primates, approximately 3 in carnivores and approximately 2 in small rodents. Another life-history correlate is sexual selection: when there is intense sperm competition among males, increased sperm production will be associated with a larger number of mitotic cell divisions in spermatogenesis and hence an increase in alpham. Male-biased mutation has implications for important aspects of evolutionary biology such as mate choice in relation to mutation load, sexual selection and the maintenance of genetic diversity despite strong directional selection, the tendency for a disproportionate large role of the X (Z) chromosome in post-zygotic isolation, and the evolution of sex.
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Affiliation(s)
- Hans Ellegren
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36 Uppsala, Sweden.
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21
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Wamhoff BR, Sinha S, Owens GK. Conditional mouse models to study developmental and pathophysiological gene function in muscle. Handb Exp Pharmacol 2007:441-68. [PMID: 17203666 DOI: 10.1007/978-3-540-35109-2_18] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This chapter will review conditional mouse model systems that have been developed to study gene function in skeletal, cardiac, and vascular smooth muscle cells in vivo with an emphasis on the utility of these models for investigating developmental and pathophysiological gene function in muscle. In general, these systems have utilized muscle-specific/selective promoter-enhancers in conjunction with site-specific DNA recombinases, e.g., Cre-loxP, and fusion proteins with these recombinases that confer temporal control, such as tamoxifen-inducible CreER systems. A major focus of this chapter will be to discuss unique challenges of studying Cre-mediated mutagenesis/gene targeting in these muscle types during development and in the adult animal, some of which are inherent of the muscle cell type being studied. For example, unlike cardiac and skeletal muscle cells, the vascular SMC is extremely plastic and able to undergo rapid phenotypic modulation to various environmental cues in vivo. Thus, employing SMC marker gene promoter enhancers for conditional gene targeting in SMCs must take into account the possibility and/or certainty that the particular SMC promoter enhancers used may or may not be transcriptionally active in SMCs of a vessel wall under normal and some pathophysiological conditions. Moreover, individual floxed loci within the same muscle cell type and tissue have different degrees of sensitivity to Cre, most likely dependent on the chromatin state of that particular gene, i.e., closed/condensed state or open/active state. Thus, Cre recombination may be ineffective for specific floxed gene DNA. Lastly, rigorous efforts must be made to confirm the degree of recombination in a tissue, taking into full account the multicellularity of the tissue, to understand the extent of the physiological effect in that organ.
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Affiliation(s)
- B R Wamhoff
- Molecular Physiology and Biological Physics, The Robert M. Berne Cardiovascular Research Center, The University of Virginia, 415 Lane Road, Medical Research Building 5, Room 1226, P.O. Box 801394, Charlottesville VA 22908, USA
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Lu Y, Amleh A, Sun J, Jin X, McCullough SD, Baer R, Ren D, Li R, Hu Y. Ubiquitination and proteasome-mediated degradation of BRCA1 and BARD1 during steroidogenesis in human ovarian granulosa cells. Mol Endocrinol 2006; 21:651-63. [PMID: 17185394 DOI: 10.1210/me.2006-0188] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Germ-line mutations in BRCA1 predispose women to early-onset, familial breast and ovarian cancers. However, BRCA1 expression is not restricted to breast and ovarian epithelial cells. For example, ovarian BRCA1 expression is enriched in ovarian granulosa cells, which are responsible for ovarian estrogen production in premenopausal women. Furthermore, recent tissue culture and animal studies suggest a functional role of BRCA1 in ovarian granulosa cells. Although levels of BRCA1 are known to fluctuate significantly during folliculogenesis and steroidogenesis, the mechanism by which BRCA1 expression is regulated in granulosa cells remains to be elucidated. Here we show that the ubiquitin-proteasome degradation pathway plays a significant role in the coordinated protein stability of BRCA1 and its partner BARD1 in ovarian granulosa cells. Our work identifies the amino-terminal RING domain-containing region of BRCA1 as the degron sequence that is both necessary and sufficient for polyubiquitination and proteasome-mediated protein degradation. Interestingly, mutations in the RING domain that abolish the ubiquitin E3 ligase activity of BRCA1 do not affect its own ubiquitination or degradation in ovarian granulosa cells. The proteasome-mediated degradation of BRCA1 and BARD1 also occurs during the cAMP-dependent steroidogenic process. Thus, the dynamic changes of BRCA1/BARD1 protein stability in ovarian granulosa cells provide an excellent paradigm for investigating the regulation of this protein complex under physiological conditions.
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Affiliation(s)
- Yunzhe Lu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, China
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23
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Scardocci A, Guidi F, D'Alo' F, Gumiero D, Fabiani E, DiRuscio A, Martini M, Larocca LM, Zollino M, Hohaus S, Leone G, Voso MT. Reduced BRCA1 expression due to promoter hypermethylation in therapy-related acute myeloid leukaemia. Br J Cancer 2006; 95:1108-13. [PMID: 17047656 PMCID: PMC2360697 DOI: 10.1038/sj.bjc.6603392] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
BRCA1 plays a pivotal role in the repair of DNA damage, especially following chemotherapy and ionising radiation. We were interested in the regulation of BRCA1 expression in acute myeloid leukaemia (AML), in particular in therapy-related forms (t-AML). Using real-time PCR and Western blot, we found that BRCA1 mRNA was expressed at barely detectable levels by normal peripheral blood granulocytes, monocytes and lymphocytes, whereas control BM-mononuclear cells and selected CD34+ progenitor cells displayed significantly higher BRCA1 expression (P=0.0003). Acute myeloid leukaemia samples showed heterogeneous BRCA1 mRNA levels, which were lower than those of normal bone marrows (P=0.0001). We found a high frequency of hypermethylation of the BRCA1 promoter region in AML (51/133 samples, 38%), in particular in patients with karyotypic aberrations (P=0.026), and in t-AML, as compared to de novo AML (76 vs 31%, P=0.0002). Examining eight primary tumour samples from hypermethylated t-AML patients, BRCA1 was hypermethylated in three of four breast cancer samples, whereas it was unmethylated in the other four tumours. BRCA1 hypermethylation correlated to reduced BRCA1 mRNA (P=0.0004), and to increased DNA methyltransferase DNMT3A (P=0.003) expression. Our data show that reduced BRCA1 expression owing to promoter hypermethylation is frequent in t-AML and that this could contribute to secondary leukaemogenesis.
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MESH Headings
- Acute Disease
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- BRCA1 Protein/genetics
- BRCA1 Protein/metabolism
- Blotting, Western
- Cell Line, Tumor
- CpG Islands/genetics
- DNA (Cytosine-5-)-Methyltransferases/genetics
- DNA (Cytosine-5-)-Methyltransferases/metabolism
- DNA Methylation
- DNA Methyltransferase 3A
- Down-Regulation/genetics
- Drug-Related Side Effects and Adverse Reactions
- Female
- HL-60 Cells
- Humans
- Jurkat Cells
- Leukemia, Myeloid/etiology
- Leukemia, Myeloid/genetics
- Leukemia, Myeloid/metabolism
- Leukemia, Myeloid/pathology
- Male
- Middle Aged
- Neoplasms/therapy
- Promoter Regions, Genetic/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Radiotherapy/adverse effects
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Affiliation(s)
- A Scardocci
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
| | - F Guidi
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
| | - F D'Alo'
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
| | - D Gumiero
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
| | - E Fabiani
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
| | - A DiRuscio
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
| | - M Martini
- Anatomia Patologica e di, Universita' Cattolica Sacro Cuore, Roma, Italy
| | - L M Larocca
- Anatomia Patologica e di, Universita' Cattolica Sacro Cuore, Roma, Italy
| | - M Zollino
- Genetica Umana, Universita' Cattolica Sacro Cuore, Roma, Italy
| | - S Hohaus
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
| | - G Leone
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
| | - M T Voso
- Istituti di Ematologia, di, Universita' Cattolica Sacro Cuore, L.go A. Gemelli, 1, 00168 Roma, Italy
- E-mail:
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24
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Evers B, Jonkers J. Mouse models of BRCA1 and BRCA2 deficiency: past lessons, current understanding and future prospects. Oncogene 2006; 25:5885-97. [PMID: 16998503 DOI: 10.1038/sj.onc.1209871] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Germline mutations in BRCA1 and BRCA2 are responsible for a large proportion of hereditary breast and ovarian cancers. Soon after the identification of both genes in the mid-1990s, investigators set out to develop mouse models for the associated disease. Whereas conventional Brca1 and Brca2 mouse mutants did not reveal a strong phenotype in a heterozygous setting, most homozygous mutations caused embryonic lethality. Consequently, development of mouse models for BRCA-associated tumorigenesis required the generation of tissue-specific conditional knockout animals. In this review, we give an overview of the conventional and the conditional mouse models of BRCA1 and BRCA2 deficiency generated over the last decade, as well as the contribution of these models to our understanding of the biological and molecular functions of BRCA1 and BRCA2. The most advanced mouse models for BRCA1- and BRCA2-associated tumorigenesis mimic human disease to the extent that they can be used in studies addressing clinically relevant questions. These models will help to resolve yet unanswered questions and to translate our increasing knowledge of BRCA1 and BRCA2 biology into clinical practice.
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Affiliation(s)
- B Evers
- Division of Molecular Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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25
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Zhoucun A, Zhang S, Yang Y, Ma Y, Zhang W, Lin L. The common variant N372H in BRCA2 gene may be associated with idiopathic male infertility with azoospermia or severe oligozoospermia. Eur J Obstet Gynecol Reprod Biol 2006; 124:61-4. [PMID: 16257105 DOI: 10.1016/j.ejogrb.2005.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2005] [Revised: 08/10/2005] [Accepted: 09/21/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To explore the possible association between the common single nucleotide polymorphism N372H in human breast cancer susceptibility gene 2 (BRCA2) and the idiopathic male infertility with azoospermia or severe oligozoospermia. STUDY DESIGN The study included 240 infertile patients with idiopathic azoospermia or severe oligozoospermia and 250 fathered controls. The allele and genotype frequencies of the polymorphism N372H in BRCA2 gene were investigated in both patients and controls using denaturing high performance liquid chromatography analysis (DHPLC). RESULTS The frequency of allele H of the polymorphism N372H in patients was significantly higher than that of the controls (23.5% versus 17.6%, OR = 1.49, 95% CI 1.06-1.97, P = 0.02) and the subjects bearing rare allele H (NH + HH) significantly increased in patients compared with controls (41.7% versus 32.4%, 95% CI 1.03-2.15, P = 0.03). CONCLUSION The results of this study suggested that the polymorphism N372H in BRCA2 gene may be associated with idiopathic male infertility with azoospermia or severe oligozoospermia.
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Affiliation(s)
- A Zhoucun
- Department of Medical Genetics, West China Hospital, Sichuan University, and Division of Human Morbid Genomics, National Key Laboratory of Biotherapy, Chengdu 610041, PR China
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26
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Giscard d'Estaing S, Perrin D, Lenoir GM, Guérin JF, Dante R. Upregulation of the BRCA1 gene in human germ cells and in preimplantation embryos. Fertil Steril 2005; 84:785-8. [PMID: 16169426 DOI: 10.1016/j.fertnstert.2005.02.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2004] [Revised: 02/23/2005] [Accepted: 02/23/2005] [Indexed: 10/25/2022]
Abstract
The quantification of BRCA1 messenger RNA molecules by a quantitative competitive one-step reverse transcriptase polymerase chain reaction method indicates that BRCA1 is upregulated both in human male and female germ cells and in preimplantation embryos. Because BRCA1 is involved in several pathways that participate in preserving intact chromosome and genome integrity, these data suggest that BRCA1 dysfunction might alter human embryogenesis or fertility.
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27
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Marcon E, Moens PB. The evolution of meiosis: recruitment and modification of somatic DNA-repair proteins. Bioessays 2005; 27:795-808. [PMID: 16015600 DOI: 10.1002/bies.20264] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Several DNA-damage detection and repair mechanisms have evolved to repair double-strand breaks induced by mutagens. Later in evolutionary history, DNA single- and double-strand cuts made possible immune diversity by V(D)J recombination and recombination at meiosis. Such cuts are induced endogenously and are highly regulated and controlled. In meiosis, DNA cuts are essential for the initiation of homologous recombination, and for the formation of joint molecule and crossovers. Many proteins that function during somatic DNA-damage detection and repair are also active during homologous recombination. However, their meiotic functions may be altered from their somatic roles through localization, posttranslational modifications and/or interactions with meiosis-specific proteins. Presumably, somatic repair functions and meiotic recombination diverged during evolution, resulting in adaptations specific to sexual reproduction. (c) 2005 Wiley Periodicals, Inc.
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Affiliation(s)
- Edyta Marcon
- Department of Biology, York University, Toronto, Canada
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28
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Suen TC, Tang MS, Goss PE. Model of transcriptional regulation of the BRCA1-NBR2 bi-directional transcriptional unit. ACTA ACUST UNITED AC 2005; 1728:126-34. [PMID: 15777733 DOI: 10.1016/j.bbaexp.2005.01.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Revised: 01/27/2005] [Accepted: 01/27/2005] [Indexed: 12/18/2022]
Abstract
In contrast to hundreds of mutations found in familial breast and/or ovarian cancers, somatic mutations of BRCA1 are very rare. However, a high percentage of sporadic breast and ovarian cancers show a reduction in BRCA1 expression, suggesting that defects in transcriptional regulation is a contributing factor. BRCA1 shares a promoter with its neighboring gene, NBR2, which is transcribed in the opposite direction. We have previously shown that the transcription of BRCA1 is negatively regulated by protein factors that interact with a 36-bp segment, located 575 bp into its first intron. We now report the localization of an 18-bp transcriptional repressor element for NBR2, which resides 948 bp into its first intron. The binding of nuclear proteins to this repressor element was detected by electrophoretic mobility shift assays (EMSAs), and it conferred an orientation-dependent functional suppression onto a heterologous thymidine kinase promoter. Combined with our previous studies, a model of transcriptional regulation of the closely aligned BRCA1-NBR2 bi-directional unit is proposed. A minimal 56-bp DNA region is functional in driving transcription in both directions, while uni-directional control is provided by distinct repressors that bind to sequences located in the first intron of the respective genes.
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Affiliation(s)
- Ting-Chung Suen
- Nelson Institute of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987, USA.
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29
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Feki A, Jefford CE, Jefford CE, Durand P, Harb J, Lucas H, Krause KH, Irminger-Finger I. BARD1 Expression During Spermatogenesis Is Associated with Apoptosis and Hormonally Regulated1. Biol Reprod 2004; 71:1614-24. [PMID: 15240424 DOI: 10.1095/biolreprod.104.029678] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The BRCA1-binding RING-finger domain protein BARD1 may act conjointly with BRCA1 in DNA repair and in ubiquitination, but it may also induce apoptosis in a BRCA1-independent manner. In this study, we have investigated BARD1 expression during spermatogenesis. In contrast with BRCA1, which is expressed only in meiotic spermatocytes and early round spermatids, BARD1 is expressed during all stages of spermatogenesis. However, while spermatogonia expressed full-length BARD1 mRNA, later stages of spermatocyte precursors express predominantly a novel, shorter splice form BARD1beta. BARD1beta lacks the BRCA1-interacting RING finger but maintains its proapoptotic activity. Consistently, BRCA1 can counteract the proapoptotic activity of full-length BARD1 but not of BARD1beta. Several lines of evidence suggest that BARD1 is involved in proapoptotic signaling in testis: i) both BARD1 isoforms are mostly found in cells that stain positive for TUNEL, Bax, and activated caspase 3; ii) BARD1beta, capable of inducing apoptosis even in the presence of BRCA1, is specifically expressed in BRCA1-positive later stages of spermatogenesis; iii) antiapoptotic hormonal stimulation leads to BARD1 downregulation; and iv) BARD1 expression is associated with human pathologies causing sterility due to increased germ cell death. Our data suggest that full-length BARD1 might be involved in apoptotic control in spermatogonia and primary spermatocytes, while a switch to the BRCA1-independent BARD1beta might be necessary to induce apoptosis in BRCA1-expressing meiotic spermatocytes and early round spermatids.
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Affiliation(s)
- Anis Feki
- Biology of Aging Laboratory, University Hospitals, CH-12225 Geneva, Switzerland
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30
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Li Q, Ching AKK, Chan BCL, Chow SKY, Lim PL, Ho TCY, Ip WK, Wong CK, Lam CWK, Lee KKH, Chan JYH, Chui YL. A death receptor-associated anti-apoptotic protein, BRE, inhibits mitochondrial apoptotic pathway. J Biol Chem 2004; 279:52106-16. [PMID: 15465831 DOI: 10.1074/jbc.m408678200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BRE, brain and reproductive organ-expressed protein, was found previously to bind the intracellular juxtamembrane domain of a ubiquitous death receptor, tumor necrosis factor receptor 1 (TNF-R1), and to down-regulate TNF-alpha-induced activation of NF-kappaB. Here we show that BRE also binds to another death receptor, Fas, and upon overexpression conferred resistance to apoptosis induced by TNF-alpha, anti-Fas agonist antibody, cycloheximide, and a variety of stress-related stimuli. However, down-regulation of the endogenous BRE by small interfering RNA increased apoptosis to TNF-alpha, but nottoetoposide, indicating that the physiological antiapoptotic role of this protein is specific to death receptor-mediated apoptosis. We further demonstrate that BRE mediates antiapoptosis by inhibiting the mitochondrial apoptotic machinery but without translocation to the mitochondria or nucleus or down-regulation of the cellular level of truncated Bid. Dissociation of BRE rapidly from TNF-R1, but not from Fas, upon receptor ligation suggests that this protein interacts with the death inducing signaling complex during apoptotic induction. Increased association of BREwith phosphorylated, sumoylated, and ubiquitinated proteins after death receptor stimulation was also detected. We conclude that in contrast to the truncated Bid that integrates mitochondrial apoptosis to death receptor-triggered apoptotic cascade, BRE inhibits the integration. We propose that BRE inhibits, by ubiquitination-like activity, components in or proximal to the death-inducing signaling complexes that are necessary for activation of the mitochondria.
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Affiliation(s)
- Qing Li
- Clinical Immunology Unit and Sir Y. K. Pao Centre for Cancer, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territory, Hong Kong Special Administrative Region, China
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31
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Jazaeri AA, Chandramouli GVR, Aprelikova O, Nuber UA, Sotiriou C, Liu ET, Ropers HH, Yee CJ, Boyd J, Barrett JC. BRCA1-mediated repression of select X chromosome genes. J Transl Med 2004; 2:32. [PMID: 15383145 PMCID: PMC520825 DOI: 10.1186/1479-5876-2-32] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Accepted: 09/21/2004] [Indexed: 12/27/2022] Open
Abstract
Recently BRCA1 has been implicated in the regulation of gene expression from the X chromosome. In this study the influence of BRCA1 on expression of X chromosome genes was investigated. Complementary DNA microarrays were used to compare the expression levels of X chromosome genes in 18 BRCA1-associated ovarian cancers to those of the 13 "BRCA1-like" and 14 "BRCA2-like" sporadic tumors (as defined by previously reported expression profiling). Significance was determined using parametric statistics with P < 0.005 as a cutoff. Forty of 178 total X-chromosome transcripts were differentially expressed between the BRCA1-associated tumors and sporadic cancers with a BRCA2-like molecular profile. Thirty of these 40 genes showed higher mean expression in the BRCA1-associated samples including all 11 transcripts that mapped to Xp11. In contrast, four of 178 total X chromosome transcripts showed significant differential expression between BRCA1-associated and sporadic tumors with a BRCA1-like molecular profile. All four mapped to Xp11 and showed higher mean expression in BRCA1-associated tumors. Re-expression of BRCA1 in HCC1937 BRCA1-deficient breast cancer cell resulted in the repression of 21 transcripts. Eleven of the 21 (54.5%) transcripts mapped to Xp11. However, there was no significant overlap between these Xp11 genes and those found to be differentially expressed between BRCA1-associated and sporadic ovarian cancer samples. These results demonstrate that BRCA1 mediates the repression of several X chromosome genes, many of which map to the Xp11 locus.
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Affiliation(s)
- Amir A Jazaeri
- From the Center for Cancer Research of the National Cancer Institute. Building 31, Room 3A11, 31 Center Drive, MSC 2440, Bethesda, MD 20892-2440 USA
| | - Gadisetti VR Chandramouli
- From the Center for Cancer Research of the National Cancer Institute. Building 31, Room 3A11, 31 Center Drive, MSC 2440, Bethesda, MD 20892-2440 USA
| | - Olga Aprelikova
- From the Center for Cancer Research of the National Cancer Institute. Building 31, Room 3A11, 31 Center Drive, MSC 2440, Bethesda, MD 20892-2440 USA
| | - Ulrike A Nuber
- Max Planck Institute for Molecular Genetics. Ihnestrasse 73, 14195 Berlin Germany
| | - Christos Sotiriou
- From the Center for Cancer Research of the National Cancer Institute. Building 31, Room 3A11, 31 Center Drive, MSC 2440, Bethesda, MD 20892-2440 USA
- Jules Bordet Institute. Microarray Unit, 121 Bld. de Waterloo, 1000 Brussels, Belgium
| | - Edison T Liu
- From the Center for Cancer Research of the National Cancer Institute. Building 31, Room 3A11, 31 Center Drive, MSC 2440, Bethesda, MD 20892-2440 USA
- Genome Institute of Singapore, 1 Science Park Rd., The Capricorn #05-01, Singapore Sicence Park II 117528, Singapore
| | - H Hilger Ropers
- Max Planck Institute for Molecular Genetics. Ihnestrasse 73, 14195 Berlin Germany
| | - Cindy J Yee
- From the Departments of Surgery and Medicine of the Memorial Sloan-Kettering Cancer Center 1275 York Ave., New York, New York, 10021 USA
| | - Jeff Boyd
- From the Departments of Surgery and Medicine of the Memorial Sloan-Kettering Cancer Center 1275 York Ave., New York, New York, 10021 USA
| | - J Carl Barrett
- From the Center for Cancer Research of the National Cancer Institute. Building 31, Room 3A11, 31 Center Drive, MSC 2440, Bethesda, MD 20892-2440 USA
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32
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Feng Z, Kachnic L, Zhang J, Powell SN, Xia F. DNA damage induces p53-dependent BRCA1 nuclear export. J Biol Chem 2004; 279:28574-84. [PMID: 15087457 DOI: 10.1074/jbc.m404137200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The tumor suppressor gene BRCA1 plays an important role in the response to DNA damage. BRCA1 function is regulated by a variety of mechanisms including transcriptional control, phosphorylation, and protein-protein interactions. Recent studies have shown that BRCA1 is a nuclear-cytoplasmic shuttle protein. Its subcellular localization is controlled by a nuclear localization signal-mediated nuclear import via the importin receptor pathway and a nuclear export signal-facilitated nuclear export through a CRM1-dependent pathway. Using the human breast cancer cell line, MCF7, the subcellular distribution of BRCA1 was assessed by immunohistochemical staining and Western blotting analyses of fractionated subcellullar extracts. Ionizing radiation stimulated BRCA1 nuclear export in a dose-dependent manner. This DNA damage-induced BRCA1 nuclear export utilized a CRM1-dependent mechanism and also required wild-type p53, whose function was abrogated by the E6 protein in MCF7 cells. In addition, the dependence on p53 was confirmed using a second cell type operating a tetracycline-inducible system. The effect of ionizing radiation on BRCA1 export was observed in every phase of the cell cycle, although BRCA1 localization did vary between the G(1), S, and G(2)/M phases. These results imply that, in addition to ATM-, ATR-, and Chk2-dependent phosphorylations, cytoplasmic relocalization of BRCA1 protein is a mechanism whereby BRCA1 function is regulated in response to DNA damage.
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Affiliation(s)
- Zhihui Feng
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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33
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Whitehouse C, Chambers J, Catteau A, Solomon E. Brca1 expression is regulated by a bidirectional promoter that is shared by the Nbr1 gene in mouse. Gene 2004; 326:87-96. [PMID: 14729266 DOI: 10.1016/j.gene.2003.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The lack of functionally disrupting mutations of BRCA1 in sporadic breast tumours has suggested that other mechanisms, including dysregulation of gene expression, might be important in tumour development. We have analysed the control of expression of murine Brca1 and the adjacent gene, Nbr1, which lie head-to-head and are separated by less than 300 bp. Our results show that the expression of these two genes is under complex regulation, through a bidirectional promoter. Brca1 expression is driven by this single promoter, whereas Nbr1 expression is driven by this and one additional promoter, which generate two distinct transcripts, differing by the alternate use of the first exons. By comparison of mRNA transcription in adult murine tissues and also in the mammary gland during pregnancy and lactation, we show that Brca1 and Nbr1 expression is coordinately regulated in a spatial and temporal manner to produce quite different patterns of expression, even from the same promoter. The analysis of the murine and human syntenic region and its control has important implications for the regulation of human and murine BRCA1/NBR1 expression and the interpretation of animal models of disease.
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Affiliation(s)
- Caroline Whitehouse
- Department of Medical and Molecular Genetics, Guy's, King's, and St. Thomas' School of Medicine, Guy's Hospital, 8th Floor, Guy's Tower, London SE1 9RT, UK.
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34
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Sharan SK, Pyle A, Coppola V, Babus J, Swaminathan S, Benedict J, Swing D, Martin BK, Tessarollo L, Evans JP, Flaws JA, Handel MA. BRCA2 deficiency in mice leads to meiotic impairment and infertility. Development 2003; 131:131-42. [PMID: 14660434 DOI: 10.1242/dev.00888] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The role of Brca2 in gametogenesis has been obscure because of embryonic lethality of the knockout mice. We generated Brca2-null mice carrying a human BAC with the BRCA2 gene. This construct rescues embryonic lethality and the mice develop normally. However, there is poor expression of the transgene in the gonads and the mice are infertile, allowing examination of the function of BRCA2 in gametogenesis. BRCA2-deficient spermatocytes fail to progress beyond the early prophase I stage of meiosis. Observations on localization of recombination-related and spermatogenic-related proteins suggest that the spermatocytes undergo early steps of recombination (DNA double strand break formation), but fail to complete recombination or initiate spermiogenic development. In contrast to the early meiotic prophase arrest of spermatocytes, some mutant oocytes can progress through meiotic prophase I, albeit with a high frequency of nuclear abnormalities, and can be fertilized and produce embryos. Nonetheless, there is marked depletion of germ cells in adult females. These studies provide evidence for key roles of the BRCA2 protein in mammalian gametogenesis and meiotic success.
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Affiliation(s)
- Shyam K Sharan
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute at Frederick, 1050 Boyles Street, Frederick, MD 21702, USA.
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35
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Korhonen L, Brännvall K, Skoglösa Y, Lindholm D. Tumor suppressor gene BRCA-1 is expressed by embryonic and adult neural stem cells and involved in cell proliferation. J Neurosci Res 2003; 71:769-76. [PMID: 12605402 DOI: 10.1002/jnr.10546] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BRCA-1 is a tumor suppressor gene that plays a role in DNA repair and cellular growth control. Here we show that BRCA-1 mRNA is expressed by embryonic rat brain and is localized to the neuroepithelium containing neuronal precursor cells. The expression of BRCA-1 decreases during rat brain development, but BRCA-1 is expressed postnatally by proliferating neuronal precursor cells in the developing cerebellum. Neural stem cells (NSC) prepared from embryonic rat brain and cultured in the presence of epidermal growth factor were positive for BRCA-1. Induction of NSC differentiation resulted in down-regulation of BRCA-1 expression as shown by RNA and protein analyses. In addition to embryonic cells, BRCA-1 is also present in NSC prepared from adult rat brain. In adult rats, BRCA1 was expressed by cells in the walls of brain ventricles and in choroid plexus. The results show that BRCA-1 is present in embryonic and adult rat NSC and that the expression is linked to NSC proliferation.
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Affiliation(s)
- L Korhonen
- Department of Neuroscience, Neurobiology, Uppsala University, Biomedical Centre, Uppsala, Sweden
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36
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Mueller CR, Roskelley CD. Regulation of BRCA1 expression and its relationship to sporadic breast cancer. Breast Cancer Res 2003; 5:45-52. [PMID: 12559046 PMCID: PMC154136 DOI: 10.1186/bcr557] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2002] [Revised: 10/17/2002] [Accepted: 10/25/2002] [Indexed: 12/20/2022] Open
Abstract
Germ-line mutations in the BRCA1 tumour suppressor gene contribute to familial breast tumour formation, but there is no evidence for direct mutation of the BRCA1 gene in the sporadic form of the disease. In contrast, decreased expression of the BRCA1 gene has been shown to be common in sporadic tumours, and the magnitude of the decrease correlates with disease progression. BRCA1 expression is also tightly regulated during normal breast development. Determining how these developmental regulators of BRCA1 expression are co-opted during breast tumourigenesis could lead to a better understanding of sporadic breast cancer aetiology and the generation of novel therapeutic strategies aimed at preventing sporadic breast tumour progression.
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37
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Vidarsson H, Mikaelsdottir EK, Rafnar T, Bertwistle D, Ashworth A, Eyfjord JE, Valgeirsdottir S. BRCA1 and BRCA2 bind Stat5a and suppress its transcriptional activity. FEBS Lett 2002; 532:247-52. [PMID: 12459499 DOI: 10.1016/s0014-5793(02)03684-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Germline mutations in the breast cancer susceptibility genes, BRCA1 and BRCA2, are thought to account for a large portion of familial breast cancer. The increased risk of breast cancer in women carrying such mutations suggests that these proteins play a critical role in the growth regulation of mammary epithelial cells. Another protein, Stat5a, is known to be essential for growth and terminal differentiation of breast epithelial cells. Here we show that Stat5a forms a complex with both BRCA1 and BRCA2 in breast epithelial cells upon stimulation with prolactin. In addition, we show that the activity of Stat5a on the beta-casein promoter is modulated by both BRCA1 and BRCA2. This interaction may be important during the expansion and terminal differentiation of breast epithelial cells, as happens during pregnancy and lactation.
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Affiliation(s)
- H Vidarsson
- Molecular and Cell Biology Research Laboratory, Icelandic Cancer Society, Reykjavik, Iceland
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38
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Kubista M, Rosner M, Miloloza A, Hofer K, Prusa AR, Kroiss R, Marton E, Hengstschläger M. Brca1 and differentiation. Mutat Res 2002; 512:165-72. [PMID: 12464350 DOI: 10.1016/s1383-5742(02)00063-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Breast cancer is one of the most frequent malignancies affecting women. The human breast cancer gene 1 (BRCA1) gene is mutated in a distinct proportion of hereditary breast and ovarian cancers. Tumourigenesis in individuals with germline BRCA1 mutations requires somatic inactivation of the remaining wild-type allelle. Although, this evidence supports a role for BRCA1 as a tumour suppressor, the mechanisms through which its loss leads to tumourigenesis remain to be determined. Neither the expression pattern nor the described functions of human BRCA1 and murine breast cancer gene 1 (Brca1) can explain the specific association of mutations in this gene with the development of breast and ovarian cancer. Investigation of the role of Brca1 in normal cell differentiation processes might provide the basis to understand the tissue-restricted properties.
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Affiliation(s)
- Marion Kubista
- AKH-EBO-E6 Division of Prenatal Diagnosis and Therapy, Obstetrics and Gynecology, University of Vienna, Währinger Gürtel 18-20, A-1090, Vienna, Austria
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39
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Abstract
We review the genes and proteins related to the homologous recombinational repair (HRR) pathway that are implicated in cancer through either genetic disorders that predispose to cancer through chromosome instability or the occurrence of somatic mutations that contribute to carcinogenesis. Ataxia telangiectasia (AT), Nijmegen breakage syndrome (NBS), and an ataxia-like disorder (ATLD), are chromosome instability disorders that are defective in the ataxia telangiectasia mutated (ATM), NBS, and Mre11 genes, respectively. These genes are critical in maintaining cellular resistance to ionizing radiation (IR), which kills largely by the production of double-strand breaks (DSBs). Bloom syndrome involves a defect in the BLM helicase, which seems to play a role in restarting DNA replication forks that are blocked at lesions, thereby promoting chromosome stability. The Werner syndrome gene (WRN) helicase, another member of the RecQ family like BLM, has very recently been found to help mediate homologous recombination. Fanconi anemia (FA) is a genetically complex chromosomal instability disorder involving seven or more genes, one of which is BRCA2. FA may be at least partially caused by the aberrant production of reactive oxidative species. The breast cancer-associated BRCA1 and BRCA2 proteins are strongly implicated in HRR; BRCA2 associates with Rad51 and appears to regulate its activity. We discuss in detail the phenotypes of the various mutant cell lines and the signaling pathways mediated by the ATM kinase. ATM's phosphorylation targets can be grouped into oxidative stress-mediated transcriptional changes, cell cycle checkpoints, and recombinational repair. We present the DNA damage response pathways by using the DSB as the prototype lesion, whose incorrect repair can initiate and augment karyotypic abnormalities.
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Affiliation(s)
- Larry H Thompson
- Biology and Biotechnology Research Program, Lawrence Livermore National Laboratory L-441, P.O. Box 808, Livermore, CA 94551-0808, USA.
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40
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Flores KG, McAllister KA, Greer PK, Wiseman RW, Hale LP. Thymic model for examining BRCA2 expression and function. Mol Carcinog 2002; 35:103-9. [PMID: 12410562 DOI: 10.1002/mc.10081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mutations in the human BRCA2 breast cancer susceptibility gene are associated with increased risks of breast, ovarian, and other cancers. BRCA2 has been hypothesized to function in processes of DNA damage/breakage repair, cell proliferation, and apoptosis. These processes continually occur in the thymus during thymocyte development, and BRCA2 mRNA is highly expressed in thymus relative to most other organs. We therefore used the thymus as a model system to study BRCA2 expression and function. Quantitative reverse transcription polymerase chain reaction experiments showed that highly activated immature CD4(+) CD8(+) double-positive human thymocytes that exhibited high levels of proliferation and apoptosis had increased BRCA2 mRNA levels relative to other thymocyte subsets. BRCA2 mRNA levels were upregulated in thymocytes treated with the DNA-damaging agent etoposide. Only modest increases were associated with proliferation in human peripheral lymphocytes in response to concanavalin A (ConA) mitogen. Mice homozygous for a targeted mutation in Brca2 exon 27 (Brca2(Delta27/Delta27)) showed normal thymic architecture but had 18% decreased thymocyte cellularity compared with wild-type mice. Thymocytes from these Brca2(Delta27/Delta27) mice displayed decreased apoptosis in response to etoposide-induced DNA damage compared with wild-type thymocytes. These studies suggest that BRCA2 mRNA levels are modulated during DNA damage and may be important during apoptosis.
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Affiliation(s)
- Kristina G Flores
- Department of Pathology, Duke University, Durham, North Carolina 27710, USA
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41
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Ganesan S, Silver DP, Greenberg RA, Avni D, Drapkin R, Miron A, Mok SC, Randrianarison V, Brodie S, Salstrom J, Rasmussen TP, Klimke A, Marrese C, Marahrens Y, Deng CX, Feunteun J, Livingston DM. BRCA1 supports XIST RNA concentration on the inactive X chromosome. Cell 2002; 111:393-405. [PMID: 12419249 DOI: 10.1016/s0092-8674(02)01052-8] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BRCA1, a breast and ovarian tumor suppressor, colocalizes with markers of the inactive X chromosome (Xi) on Xi in female somatic cells and associates with XIST RNA, as detected by chromatin immunoprecipitation. Breast and ovarian carcinoma cells lacking BRCA1 show evidence of defects in Xi chromatin structure. Reconstitution of BRCA1-deficient cells with wt BRCA1 led to the appearance of focal XIST RNA staining without altering XIST abundance. Inhibiting BRCA1 synthesis in a suitable reporter line led to increased expression of an otherwise silenced Xi-located GFP transgene. These observations suggest that loss of BRCA1 in female cells may lead to Xi perturbation and destabilization of its silenced state.
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Affiliation(s)
- Shridar Ganesan
- The Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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42
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Gilliam LK, Lobenhofer EK, Greer PK, Scearce RM, Cirisano FD, Marks JR, Hale LP. BRCA2 monoclonal antibodies react with differentiating epithelium. HYBRIDOMA AND HYBRIDOMICS 2002; 21:261-9. [PMID: 12193279 DOI: 10.1089/153685902760213877] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The BRCA2 gene has previously been suggested to play a role in proliferation and DNA repair. Germline mutations in the BRCA2 gene predispose individuals to early onset, hereditary breast cancer. To better understand the expression pattern and function of the BRCA2 gene product, we have developed immunological reagents specific for BRCA2. These reagents recognize full-length (384 kDa) recombinant human BRCA2 proteins in transfected cell lysates as well as multiple smaller recombinant BRCA2 polypeptides. Detection of native BRCA2 protein in most tissue types, including breast epithelium, requires sensitive techniques such as immunoprecipitation-Western blot analysis. However, we have demonstrated strong reactivity of our immunological reagents with differentiating epithelium, including epidermis, thymic epithelium, and squamous cell carcinoma. These data suggest that BRCA2 may play a role in processes associated with cellular differentiation, in addition to its previously suggested roles in proliferation and DNA repair.
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Affiliation(s)
- Lisa K Gilliam
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
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43
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Whittle CA, Johnston MO. Male-driven evolution of mitochondrial and chloroplastidial DNA sequences in plants. Mol Biol Evol 2002; 19:938-49. [PMID: 12032250 DOI: 10.1093/oxfordjournals.molbev.a004151] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although there is substantial evidence that, in animals, male-inherited neutral DNA evolves at a higher rate than female-inherited DNA, the relative evolutionary rate of male- versus female-inherited DNA has not been investigated in plants. We compared the substitution rates at neutral sites of maternally and paternally inherited organellar DNA in gymnosperms. The analysis provided substantial support for the presence of a higher evolutionary rate in both the mitochondrial and chloroplastidial DNA when the organelle was inherited paternally than when inherited maternally. These results suggest that, compared with eggs, sperm tend to carry a greater number of mutations in mitochondrial and chloroplastidial DNA. The existence of a male mutation bias in plants is remarkable because, unlike animals, the germ-lines are not separated from the somatic cells throughout an individual's lifetime. The data therefore suggest that even a brief period of male and female germ-line separation can cause gender-specific mutation rates. These results are the first to show that, at least in some species, germ-lines influence the number of mutations carried in the gametes. Possible causes of male mutation bias in plants are discussed.
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Affiliation(s)
- Carrie-Ann Whittle
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
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44
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Vissac C, Lémery D, Le Corre L, Fustier P, Déchelotte P, Maurizis JC, Bignon YJ, Bernard-Gallon DJ. Presence of BRCA1 and BRCA2 proteins in human milk fat globules after delivery. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1586:50-6. [PMID: 11781149 DOI: 10.1016/s0925-4439(01)00085-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We evaluated BRCA1 and BRCA2 oncosuppressor protein expression in 26 milk samples in women just after delivery. The quantification of BRCA1 and BRCA2 proteins was performed in isolated milk fat globules using an affinity chromatography strategy. The amounts of BRCA1 and BRCA2 proteins were found to be similar. We explained the presence of BRCA1 and BRCA2 proteins in human milk fat globules by the fact that they are formed by exocytosis of lipids from epithelial cells of the mammary gland and are enveloped by plasma membrane from the apical part of the milk-secreting cells. This raises the possibility that BRCA1 and BRCA2 proteins are a protective response to proliferation and play a possible role in newborn nutrition.
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Affiliation(s)
- Cécile Vissac
- Laboratoire d'Oncologie Moléculaire, Centre Jean Perrin, 63011 Clermont-Ferrand, France
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45
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Abstract
Inheritance of one defective copy of either of the two breast-cancer-susceptibility genes, BRCA1 and BRCA2, predisposes individuals to breast, ovarian and other cancers. Both genes encode very large protein products; these bear little resemblance to one another or to other known proteins, and their precise biological functions remain uncertain. Recent studies reveal that the BRCA proteins are required for maintenance of chromosomal stability in mammalian cells and function in the biological response to DNA damage. The new work suggests that, although the phenotypic consequences of their disruption are similar, BRCA1 and BRCA2 play distinct roles in the mechanisms that lead to the repair of DNA double-strand breaks.
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Affiliation(s)
- A R Venkitaraman
- University of Cambridge, CRC Department of Oncology and The Medical Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 2XZ, UK.
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46
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Vooijs M, Jonkers J, Berns A. A highly efficient ligand-regulated Cre recombinase mouse line shows that LoxP recombination is position dependent. EMBO Rep 2001; 2:292-7. [PMID: 11306549 PMCID: PMC1083861 DOI: 10.1093/embo-reports/kve064] [Citation(s) in RCA: 284] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Conditional gene inactivation using the Cre/loxP system is widely used, but the difficulty in properly regulating Cre expression remains one of the bottlenecks. One approach to regulate Cre activity utilizes a mutant estrogen hormone-binding domain (ERT) to keep Cre inactive unless the non-steroidal estrogen analog 4-hydroxytamoxifen (OHT) is present. Here we describe a mouse strain expressing Cre-ERT from the ubiquitously expressed ROSA26 (R26) locus. We demonstrate efficient temporal and spatial regulation of Cre recombination in vivo and in primary cells derived from these mice. We show the existence of marked differences in recombination frequencies between different substrates within the same cell. This has important consequences when concurrent switching of multiple alleles within the same cell is needed, and highlights one of the difficulties that may be encountered when using reporter mice as indicator strains.
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Affiliation(s)
- M Vooijs
- The Netherlands Cancer Institute, Division of Molecular Genetics, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
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47
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Suen TC, Goss PE. Identification of a novel transcriptional repressor element located in the first intron of the human BRCA1 gene. Oncogene 2001; 20:440-50. [PMID: 11313975 DOI: 10.1038/sj.onc.1204078] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2000] [Revised: 11/02/2000] [Accepted: 11/02/2000] [Indexed: 01/13/2023]
Abstract
Loss or lowered expression of BRCA1 in non-familial breast cancer has been shown in several recent studies. Understanding how BRCA1 expression is regulated should provide new insights into the role of BRCA1 in sporadic breast cancer. We have recently identified a critical 18-base pair (bp) DNA element within the minimal BRCA1 promoter whereupon the formation of a specific protein-DNA complex and transcription of BRCA1 is dependent. We now report a non tissue-specific transcriptional repressor activity, located more than 500 bp into the first intron of BRCA1. Progressive deletions from the 3'-end of intron 1 and reporter gene assays localized the repressor activity to an 83-bp region. Electrophoretic mobility shift assays with this 83 bp DNA and various sub-fragments of it showed binding of nuclear proteins to a 36 bp BstNI-BseRI fragment. Functional transcriptional repression by this 36 bp DNA could be conferred on a heterologous thymidine kinase promoter. Analysis of multiple reporter gene constructs containing the BRCA1 genomic region driving transcription in both directions suggests that the putative negative regulatory element functions to block transcription only in the BRCA1 direction, although the promoter is shared by the divergently transcribed NBR2 gene.
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Affiliation(s)
- T C Suen
- Breast Cancer Prevention Program, The Toronto Hospital, Oncology Research Laboratories, Ontario M5G 2M9, Canada
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48
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Dimitrov S, Brennerova M, Forejt J. Expression profiles and intergenic structure of head-to-head oriented Brca1 and Nbr1 genes. Gene 2001; 262:89-98. [PMID: 11179671 DOI: 10.1016/s0378-1119(00)00549-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mouse and human Brca1/BRCA1 and Nbr1/NBR2 genes lie head-to-head, being transcribed from the opposite strands. The normal function of Brca1 is associated with DNA damage-related responses and the maintenance of genome integrity. Mutations of this gene are major risk factors for developing breast and ovarian cancers. The function of Nbr1 is unknown. Here we analyzed expression profiles of Brca1 and a newly identified, evolutionary conserved isoform of Nbr1(1a) transcript. In adult testis, the Nbr1(1a) mRNA showed an 18-fold higher steady-state level than the ubiquitous Nbr1(1b) form and its expression was confined mainly to spermatids. The expression profile of Brca1 paralleled that of Nbr1(1b). The Nbr1(1a) mRNA was not significantly expressed in normal somatic tissues, but was found on a list of cDNA clones from a human myeloblast cell line. The newly defined intergenic region (289 bp) between Nbr1 and Brca1 in the mouse and rat corresponds well to that of human BRCA1-NBR2 region.
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Affiliation(s)
- S Dimitrov
- Department of Mammalian Molecular Genetics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 4, Prague, Czech Republic
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49
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Bernard-Gallon DJ, Déchelotte P, Vissac C, Aunoble B, Cravello L, Malpuech G, Bignon YJ. BRCA1 and BRCA2 protein expressions in an ovotestis of a 46, XX true hermaphrodite. Breast Cancer Res 2001; 3:61-5. [PMID: 11250747 PMCID: PMC13901 DOI: 10.1186/bcr272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2000] [Revised: 08/30/2000] [Accepted: 09/11/2000] [Indexed: 11/23/2022] Open
Abstract
BRCA1 and BRCA2 breast cancer susceptibility genes encode proteins, the normal cellular functions of which are complex and multiple, and germ-line mutations in individuals predispose both to breast and to ovarian cancer. There is nevertheless substantial evidence linking BRCA1 and BRCA2 to homologous recombination and DNA repair, to transcriptional control and to tissue proliferation. There is controversy regarding the localization of BRCA1 and BRCA2 proteins to either nucleus or cytoplasm and whether the expression is present in premeiotic germ cells or can still be expressed in mitotic spermatogonia. We report herein an immunohistochemical study of BRCA1 and BRCA2 distribution in a rather unusual tissue (an ovotestis), which addresses this issue.
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Affiliation(s)
| | - Pierre Déchelotte
- Service d'Anatomie Pathologique, CHU/Hôtel Dieu, Clermont-Ferrand, France
| | - Cécile Vissac
- Laboratoire d'Oncologie Moléculaire, Centre Jean Perrin, Clermont-Ferrand, France
| | - Bénédicte Aunoble
- Laboratoire d'Oncologie Moléculaire, Centre Jean Perrin, Clermont-Ferrand, France
| | - Laetitia Cravello
- Laboratoire d'Oncologie Moléculaire, Centre Jean Perrin, Clermont-Ferrand, France
| | | | - Yves-Jean Bignon
- Laboratoire d'Oncologie Moléculaire, Centre Jean Perrin, Clermont-Ferrand, France
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50
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Scully R, Puget N, Vlasakova K. DNA polymerase stalling, sister chromatid recombination and the BRCA genes. Oncogene 2000; 19:6176-83. [PMID: 11156531 DOI: 10.1038/sj.onc.1203971] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Heritable predisposition to breast and/or ovarian cancer is determined, in part, by germline mutation affecting one of two tumor suppressor genes, BRCA1 and BRCA2 (Miki et al., 1994; Wooster et al., 1995). These genes are required for the maintenance of genomic integrity and for control of homologous recombination in somatic and meiotic cells. Here, we explore the hypothesis that a major role of the BRCA gene products in the somatic DNA damage response centers upon the control of recombination between sister chromatids during S phase. By analogy with model organisms, we suggest that stalling of a mammalian DNA polymerase complex by its encounter with abnormal DNA structure calls forth a series of responses that collaborate to enforce appropriate recombinational outcomes, and to suppress inappropriate or 'illegitimate' recombination.
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Affiliation(s)
- R Scully
- Dana Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115, USA
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