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Yanagihara H, Morioka T, Yamazaki S, Yamada Y, Tachibana H, Daino K, Tsuruoka C, Amasaki Y, Kaminishi M, Imaoka T, Kakinuma S. Interstitial deletion of the Apc locus in β-catenin-overexpressing cells is a signature of radiation-induced intestinal tumors in C3B6F1 ApcMin/+ mice†. JOURNAL OF RADIATION RESEARCH 2023; 64:622-631. [PMID: 37117033 DOI: 10.1093/jrr/rrad021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/13/2023] [Indexed: 05/27/2023]
Abstract
Recent studies have identified interstitial deletions in the cancer genome as a radiation-related mutational signature, although most of them do not fall on cancer driver genes. Pioneering studies in the field have indicated the presence of loss of heterozygosity (LOH) spanning Apc in a subset of sporadic and radiation-induced intestinal tumors of ApcMin/+ mice, albeit with a substantial subset in which LOH was not detected; whether copy number losses accompany such LOH has also been unclear. Herein, we analyzed intestinal tumors of C3B6F1 ApcMin/+ mice that were either left untreated or irradiated with 2 Gy of γ-rays. We observed intratumor mosaicism with respect to the nuclear/cytoplasmic accumulation of immunohistochemically detectable β-catenin, which is a hallmark of Apc+ allele loss. An immunoguided laser microdissection approach enabled the detection of LOH involving the Apc+ allele in β-catenin-overexpressing cells; in contrast, the LOH was not observed in the non-overexpressing cells. With this improvement, LOH involving Apc+ was detected in all 22 tumors analyzed, in contrast to what has been reported previously. The use of a formalin-free fixative facilitated the LOH and microarray-based DNA copy number analyses, enabling the classification of the aberrations as nondisjunction/mitotic recombination type or interstitial deletion type. Of note, the latter was observed only in radiation-induced tumors (nonirradiated, 0 of 8; irradiated, 11 of 14). Thus, an analysis considering intratumor heterogeneity identifies interstitial deletion involving the Apc+ allele as a causative radiation-related event in intestinal tumors of ApcMin/+ mice, providing an accurate approach for attributing individual tumors to radiation exposure.
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Affiliation(s)
- Hiromi Yanagihara
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Takamitsu Morioka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Shunsuke Yamazaki
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Yutaka Yamada
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Hirotaka Tachibana
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Biology, Graduate School of Science, Chiba University, Chiba, Japan
| | - Kazuhiro Daino
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Biology, Graduate School of Science, Chiba University, Chiba, Japan
| | - Chizuru Tsuruoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Yoshiko Amasaki
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Mutsumi Kaminishi
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
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Nishimura M, Daino K, Fukuda M, Tanaka I, Moriyama H, Showler K, Nishimura Y, Takabatake M, Kokubo T, Ishikawa A, Inoue K, Fukushi M, Kakinuma S, Imaoka T, Shimada Y. Development of mammary cancer in γ-irradiated F1 hybrids of susceptible Sprague-Dawley and resistant Copenhagen rats, with copy-number losses that pinpoint potential tumor suppressors. PLoS One 2021; 16:e0255968. [PMID: 34388197 PMCID: PMC8362979 DOI: 10.1371/journal.pone.0255968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 07/28/2021] [Indexed: 01/03/2023] Open
Abstract
Copenhagen rats are highly resistant to mammary carcinogenesis, even after treatment with chemical carcinogens and hormones; most studies indicate that this is a dominant genetic trait. To test whether this trait is also dominant after radiation exposure, we characterized the susceptibility of irradiated Copenhagen rats to mammary carcinogenesis, as well as its inheritance, and identified tumor-suppressor genes that, when inactivated or mutated, may contribute to carcinogenesis. To this end, mammary cancer-susceptible Sprague-Dawley rats, resistant Copenhagen rats, and their F1 hybrids were irradiated with 4 Gy of γ-rays, and tumor development was monitored. Copy-number variations and allelic imbalances of genomic DNA were studied using microarrays and PCR analysis of polymorphic markers. Gene expression was assessed by quantitative PCR in normal tissues and induced mammary cancers of F1 rats. Irradiated Copenhagen rats exhibited a very low incidence of mammary cancer. Unexpectedly, this resistance trait did not show dominant inheritance in F1 rats; rather, they exhibited intermediate susceptibility levels (i.e., between those of their parent strains). The susceptibility of irradiated F1 rats to the development of benign mammary tumors (i.e., fibroadenoma and adenoma) was also intermediate. Copy-number losses were frequently observed in chromosome regions 1q52-54 (24%), 2q12-15 (33%), and 3q31-42 (24%), as were focal (38%) and whole (29%) losses of chromosome 5. Some of these chromosomal regions exhibited allelic imbalances. Many cancer-related genes within these regions were downregulated in mammary tumors as compared with normal mammary tissue. Some of the chromosomal losses identified have not been reported previously in chemically induced models, implying a novel mechanism inherent to the irradiated model. Based on these findings, Sprague-Dawley × Copenhagen F1 rats offer a useful model for exploring genes responsible for radiation-induced mammary cancer, which apparently are mainly located in specific regions of chromosomes 1, 2, 3 and 5.
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Affiliation(s)
- Mayumi Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Kazuhiro Daino
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Maki Fukuda
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
- Radiobiology for Children’s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Ikuya Tanaka
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
- Radiobiology for Children’s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Hitomi Moriyama
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Kaye Showler
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
- Radiobiology for Children’s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Yukiko Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Masaru Takabatake
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Toshiaki Kokubo
- Laboratory Animal and Genome Sciences Section, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Atsuko Ishikawa
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Kazumasa Inoue
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Masahiro Fukushi
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
- * E-mail: (TI); (YS)
| | - Yoshiya Shimada
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan
- * E-mail: (TI); (YS)
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Hovhannisyan G, Harutyunyan T, Aroutiounian R, Liehr T. DNA Copy Number Variations as Markers of Mutagenic Impact. Int J Mol Sci 2019; 20:ijms20194723. [PMID: 31554154 PMCID: PMC6801639 DOI: 10.3390/ijms20194723] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 12/26/2022] Open
Abstract
DNA copy number variation (CNV) occurs due to deletion or duplication of DNA segments resulting in a different number of copies of a specific DNA-stretch on homologous chromosomes. Implications of CNVs in evolution and development of different diseases have been demonstrated although contribution of environmental factors, such as mutagens, in the origin of CNVs, is poorly understood. In this review, we summarize current knowledge about mutagen-induced CNVs in human, animal and plant cells. Differences in CNV frequencies induced by radiation and chemical mutagens, distribution of CNVs in the genome, as well as adaptive effects in plants, are discussed. Currently available information concerning impact of mutagens in induction of CNVs in germ cells is presented. Moreover, the potential of CNVs as a new endpoint in mutagenicity test-systems is discussed.
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Affiliation(s)
- Galina Hovhannisyan
- Department of Genetics and Cytology, Yerevan State University, Alex Manoogian 1, 0025 Yerevan, Armenia.
| | - Tigran Harutyunyan
- Department of Genetics and Cytology, Yerevan State University, Alex Manoogian 1, 0025 Yerevan, Armenia.
| | - Rouben Aroutiounian
- Department of Genetics and Cytology, Yerevan State University, Alex Manoogian 1, 0025 Yerevan, Armenia.
| | - Thomas Liehr
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Am Klinikum 1, D-07747 Jena, Germany.
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Iizuka D, Izumi S, Suzuki F, Kamiya K. Analysis of a lectin microarray identifies altered sialylation of mouse serum glycoproteins induced by whole-body radiation exposure. JOURNAL OF RADIATION RESEARCH 2019; 60:189-196. [PMID: 30521038 PMCID: PMC6430252 DOI: 10.1093/jrr/rry100] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/19/2018] [Indexed: 05/08/2023]
Abstract
Microarrays containing 45 different lectins were analyzed to identify global changes in the glycosylation of serum glycoproteins from mice exposed to whole-body γ-radiation. The results showed that radiation exposure increased and decreased the relative amounts of α-2,3- and α-2,6-sialic acids, respectively. The expression of α-2,3- and α-2,6-sialyltransferase genes in the liver was analyzed to determine whether changes in their expression were responsible for the sialic acid changes. The increase in α-2,3-sialic acid correlated with St3gal5 upregulation after radiation exposure; however, a decrease in St6gal1 expression was not observed. Analysis of a PCR array of genes expressed in irradiated mouse livers revealed that irradiation did not alter the expression of most of the included genes. These results suggest that glycomic screening of serum glycoproteins using lectin microarrays can be a powerful tool for identifying radiation-induced changes in the post-translational addition of sugar moieties to proteins. In addition, the results indicate that altered sialylation of glycoproteins may be an initial response to acute radiation exposure.
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Affiliation(s)
- Daisuke Iizuka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Japan
- Department of Experimental Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, Japan
- Corresponding author. Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan. Tel: +81-43-206-3160; Fax: +81-43-206-4138;
| | - Shunsuke Izumi
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, 1-3-2, Kagamiyama, Higashi-Hiroshima, Japan
| | - Fumio Suzuki
- Department of Molecular Radiobiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, Japan
| | - Kenji Kamiya
- Department of Experimental Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, Japan
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5
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Calabrese EJ. The additive to background assumption in cancer risk assessment: A reappraisal. ENVIRONMENTAL RESEARCH 2018; 166:175-204. [PMID: 29890424 DOI: 10.1016/j.envres.2018.05.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/08/2018] [Accepted: 05/11/2018] [Indexed: 05/21/2023]
Abstract
The assumption that chemical and radiation induced cancers act in a manner that is additive to background was proposed in the mid-1970s. It was adopted by the U.S. Environmental Protection Agency (EPA) in 1986 and then subsequently by other regulatory agencies worldwide for cancer risk assessment. It ensured that cancer risks at low doses act in a linear fashion. The additive to background process assumes that the mechanism(s) resulting in induced (i.e., treatment related) and spontaneous (i.e., control group) cancers are identical. This assumption could not be properly evaluated due to inadequate mechanistic data when it was proposed in the 1970s. Using the findings of modern molecular toxicology, including oncogene activation/mutation, gene regulation, and molecular pathway analyses, the additive to background assumption was evaluated in the present paper. Based on published studies with 45 carcinogens over 13 diverse mammalian models and for a broad range of tumor types compelling evidence indicates that carcinogen-induced tumors are mediated in general via mechanisms that are not identical to those affecting the occurrence of the same type of spontaneous tumors in appropriate control groups. These findings, which challenge a fundamental assumption of the additive to background concept, have significant implications for cancer risk assessment policy, regulatory agency practices, as well as fundamental concepts of cancer biology.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, University of Massachusetts, Morrill I, N344, Amherst, MA 01003, United States.
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Takabatake M, Daino K, Imaoka T, Blyth BJ, Kokubo T, Nishimura Y, Showler K, Hosoki A, Moriyama H, Nishimura M, Kakinuma S, Fukushi M, Shimada Y. Differential effect of parity on rat mammary carcinogenesis after pre- or post-pubertal exposure to radiation. Sci Rep 2018; 8:14325. [PMID: 30254198 PMCID: PMC6156598 DOI: 10.1038/s41598-018-32406-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 09/03/2018] [Indexed: 01/28/2023] Open
Abstract
Radiation exposure during the peri-pubertal period is a proven risk factor for breast cancer, whereas parity is an established protective factor. The present study investigated whether parity imposes differential protective effects against radiation-induced rat mammary carcinoma depending on the age at exposure. Pre- and post-pubertal female rats, irradiated or left unirradiated, were mated and allowed to nurse until weaning or left unmated. Appearance of mammary tumors was monitored, and serum concentrations of estradiol and progesterone were measured following weaning. Carcinomas were evaluated by immunohistochemistry for estrogen receptor, progesterone receptor, and the cell proliferation marker Ki-67. Parity reduced the risk of carcinoma in unirradiated and pre-pubertally irradiated rats but not post-pubertally irradiated rats. Although radiation exposure increased serum progesterone level, parity after pre-pubertal exposure significantly decreased the elevated progesterone to a normal level, reflecting a protective effect. Moreover, parity significantly decreased the proportion of hormone receptor-positive carcinomas after pre-pubertal exposure. Parity was also related to the observed positive association between progesterone receptor and Ki-67 indices in cancer tissue, implying progesterone receptor-dependent cell proliferation. Thus, parity protects against radiation-induced rat mammary carcinogenesis depending on the age at exposure; the mechanisms may involve changes in hormone levels and cancer tissue.
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Affiliation(s)
- Masaru Takabatake
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan.
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan.
| | - Kazuhiro Daino
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
| | - Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan
| | - Benjamin J Blyth
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, 3000, Australia
| | - Toshiaki Kokubo
- Department of Engineering and Safety, NIRS, QST, Chiba, 263-8555, Japan
| | - Yukiko Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
| | - Kaye Showler
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan
- Department of Radiology, The Jikei University Hospital, Tokyo, 105-8471, Japan
| | - Ayaka Hosoki
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Healios K.K. Kobe Research Institute, Kobe, 650-0047, Japan
| | - Hitomi Moriyama
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan
| | - Mayumi Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
| | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
| | - Masahiro Fukushi
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan
| | - Yoshiya Shimada
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan.
- Executive Director, QST, Chiba, 263-8555, Japan.
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Showler K, Nishimura M, Daino K, Imaoka T, Nishimura Y, Morioka T, Blyth BJ, Kokubo T, Takabatake M, Fukuda M, Moriyama H, Kakinuma S, Fukushi M, Shimada Y. Analysis of genes involved in the PI3K/Akt pathway in radiation- and MNU-induced rat mammary carcinomas. JOURNAL OF RADIATION RESEARCH 2017; 58:183-194. [PMID: 27738081 PMCID: PMC5571612 DOI: 10.1093/jrr/rrw097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/11/2016] [Accepted: 08/30/2016] [Indexed: 05/31/2023]
Abstract
The PI3K/AKT pathway is one of the most important signaling networks in human breast cancer, and since it was potentially implicated in our preliminary investigations of radiation-induced rat mammary carcinomas, our aim here was to verify its role. We included mammary carcinomas induced by the chemical carcinogen 1-methyl-1-nitrosourea to determine whether any changes were radiation-specific. Most carcinomas from both groups showed activation of the PI3K/AKT pathway, but phosphorylation of AKT1 was often heterogeneous and only present in a minority of carcinoma cells. The negative pathway regulator Inpp4b was significantly downregulated in both groups, compared with in normal mammary tissue, and radiation-induced carcinomas also showed a significant decrease in Pten expression, while the chemically induced carcinomas showed a decrease in Pik3r1 and Pdk1. Significant upregulation of the positive regulators Erbb2 and Pik3ca was observed only in chemically induced carcinomas. However, no genes showed clear correlations with AKT phosphorylation levels, except in individual carcinomas. Only rare carcinomas showed mutations in PI3K/AKT pathway genes, yet these carcinomas did not exhibit stronger AKT phosphorylation. Thus, while AKT phosphorylation is a common feature of rat mammary carcinomas induced by radiation or a canonical chemical carcinogen, the mutation of key genes in the pathways or permanent changes to gene expression of particular signaling proteins do not explain the pathway activation in the advanced cancers. Although AKT signaling likely facilitates cancer development and growth in rat mammary carcinomas, it is unlikely that permanent disruption of the PI3K/AKT pathway genes is a major causal event in radiation carcinogenesis.
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Affiliation(s)
- Kaye Showler
- Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo 116-8551, Japan
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Mayumi Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Kazuhiro Daino
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Yukiko Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Takamitsu Morioka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Benjamin J. Blyth
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Toshiaki Kokubo
- Department of Engineering and Safety, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Masaru Takabatake
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Maki Fukuda
- Faculty of Health Sciences, Tokyo Metropolitan University, Tokyo 116-8551, Japan
| | - Hitomi Moriyama
- Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo 116-8551, Japan
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Masahiro Fukushi
- Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo 116-8551, Japan
- Faculty of Health Sciences, Tokyo Metropolitan University, Tokyo 116-8551, Japan
| | - Yoshiya Shimada
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan
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8
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DNA Methylation Patterns in Rat Mammary Carcinomas Induced by Pre- and Post-Pubertal Irradiation. PLoS One 2016; 11:e0164194. [PMID: 27711132 PMCID: PMC5053445 DOI: 10.1371/journal.pone.0164194] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 09/21/2016] [Indexed: 01/18/2023] Open
Abstract
Several lines of evidence indicate one’s age at exposure to radiation strongly modifies the risk of radiation-induced breast cancer. We previously reported that rat mammary carcinomas induced by pre- and post-pubertal irradiation have distinct gene expression patterns, but the changes underlying these differences have not yet been characterized. The aim of this investigation was to see if differences in CpG DNA methylation were responsible for the differences in gene expression between age at exposure groups observed in our previous study. DNA was obtained from the mammary carcinomas arising in female Sprague-Dawley rats that were either untreated or irradiated (γ-rays, 2 Gy) during the pre- or post-pubertal period (3 or 7 weeks old). The DNA methylation was analyzed using CpG island microarrays and the results compared to the gene expression data from the original study. Global DNA hypomethylation in tumors was accompanied by gene-specific hypermethylation, and occasionally, by unique tumor-specific patterns. We identified methylation-regulated gene expression candidates that distinguished the pre- and post-pubertal irradiation tumors, but these represented only 2 percent of the differentially expressed genes, suggesting that methylation is not a major or primary mechanism underlying the phenotypes. Functional analysis revealed that the candidate methylation-regulated genes were enriched for stem cell differentiation roles, which may be important in mammary cancer development and worth further investigation. However, the heterogeneity of human breast cancer means that the interpretation of molecular and phenotypic differences should be cautious, and take into account the co-variates such as hormone receptor status and cell-of-origin that may influence the associations.
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Selmansberger M, Feuchtinger A, Zurnadzhy L, Michna A, Kaiser JC, Abend M, Brenner A, Bogdanova T, Walch A, Unger K, Zitzelsberger H, Hess J. CLIP2 as radiation biomarker in papillary thyroid carcinoma. Oncogene 2014; 34:3917-25. [DOI: 10.1038/onc.2014.311] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 07/16/2014] [Accepted: 08/09/2014] [Indexed: 12/16/2022]
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10
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Nemes S, Danielsson A, Parris TZ, Jonasson JM, Bülow E, Karlsson P, Steineck G, Helou K. A diagnostic algorithm to identify paired tumors with clonal origin. Genes Chromosomes Cancer 2013; 52:1007-16. [DOI: 10.1002/gcc.22096] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 07/02/2013] [Indexed: 11/07/2022] Open
Affiliation(s)
- Szilárd Nemes
- Division of Clinical Cancer Epidemiology; Department of Oncology; Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg; Gothenburg Sweden
- Regional Cancer Centre (West); Western Sweden Health Care Region, Sahlgrenska University Hospital; Gothenburg Sweden
| | - Anna Danielsson
- Department of Oncology; Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg; Gothenburg Sweden
| | - Toshima Z. Parris
- Department of Oncology; Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg; Gothenburg Sweden
| | - Junmei Miao Jonasson
- Division of Clinical Cancer Epidemiology; Department of Oncology; Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg; Gothenburg Sweden
| | - Erik Bülow
- Regional Cancer Centre (West); Western Sweden Health Care Region, Sahlgrenska University Hospital; Gothenburg Sweden
| | - Per Karlsson
- Department of Oncology; Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg; Gothenburg Sweden
| | - Gunnar Steineck
- Division of Clinical Cancer Epidemiology; Department of Oncology; Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg; Gothenburg Sweden
- Division of Clinical Cancer Epidemiology; Department of Oncology and Pathology; Karolinska Institutet; Stockholm Sweden
| | - Khalil Helou
- Department of Oncology; Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg; Gothenburg Sweden
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Iizuka D, Imaoka T, Nishimura M, Kawai H, Suzuki F, Shimada Y. Aberrant microRNA expression in radiation-induced rat mammary cancer: the potential role of miR-194 overexpression in cancer cell proliferation. Radiat Res 2012; 179:151-9. [PMID: 23273170 DOI: 10.1667/rr2927.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Aberrant expression of microRNAs (miRNAs) is frequently associated with a variety of cancers, including breast cancer. We and others have demonstrated that radiation-induced rat mammary cancer exhibits a characteristic gene expression profile and a random increase in aberrant DNA copy number; however, the role of aberrant miRNA expression is unclear. We performed a microarray analysis of frozen samples of eight mammary cancers induced by γ irradiation (2 Gy), eight spontaneous mammary cancers and seven normal mammary samples. We found that a small set of miRNAs was characteristically overexpressed in radiation-induced cancer. Quantitative RT-PCR analysis confirmed that miR-135b, miR-192, miR-194 and miR-211 were significantly up-regulated in radiation-induced mammary cancer compared with spontaneous cancer and normal mammary tissue. The expression of miR-192 and miR-194 also was up-regulated in human breast cancer cell lines compared with noncancer cells. Manipulation of the miR-194 expression level using a synthetic inhibiting RNA produced a small but significant suppression of cell proliferation and upregulation in the expression of several genes that are thought to act as tumor suppressors in MCF-7 and T47D breast cancer cells. Our data suggest that the induction of rat mammary cancer by radiation involves aberrant expression of miRNAs, which may facilitate cell proliferation.
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Affiliation(s)
- Daisuke Iizuka
- Department of Molecular Radiobiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553, Japan
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Oikawa M, Yoshiura KI, Kondo H, Miura S, Nagayasu T, Nakashima M. Significance of genomic instability in breast cancer in atomic bomb survivors: analysis of microarray-comparative genomic hybridization. Radiat Oncol 2011; 6:168. [PMID: 22152285 PMCID: PMC3280193 DOI: 10.1186/1748-717x-6-168] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 12/07/2011] [Indexed: 01/04/2023] Open
Abstract
Background It has been postulated that ionizing radiation induces breast cancers among atomic bomb (A-bomb) survivors. We have reported a higher incidence of HER2 and C-MYC oncogene amplification in breast cancers from A-bomb survivors. The purpose of this study was to clarify the effect of A-bomb radiation exposure on genomic instability (GIN), which is an important hallmark of carcinogenesis, in archival formalin-fixed paraffin-embedded (FFPE) tissues of breast cancer by using microarray-comparative genomic hybridization (aCGH). Methods Tumor DNA was extracted from FFPE tissues of invasive ductal cancers from 15 survivors who were exposed at 1.5 km or less from the hypocenter and 13 calendar year-matched non-exposed patients followed by aCGH analysis using a high-density oligonucleotide microarray. The total length of copy number aberrations (CNA) was used as an indicator of GIN, and correlation with clinicopathological factors were statistically tested. Results The mean of the derivative log ratio spread (DLRSpread), which estimates the noise by calculating the spread of log ratio differences between consecutive probes for all chromosomes, was 0.54 (range, 0.26 to 1.05). The concordance of results between aCGH and fluorescence in situ hybridization (FISH) for HER2 gene amplification was 88%. The incidence of HER2 amplification and histological grade was significantly higher in the A-bomb survivors than control group (P = 0.04, respectively). The total length of CNA tended to be larger in the A-bomb survivors (P = 0.15). Correlation analysis of CNA and clinicopathological factors revealed that DLRSpread was negatively correlated with that significantly (P = 0.034, r = -0.40). Multivariate analysis with covariance revealed that the exposure to A-bomb was a significant (P = 0.005) independent factor which was associated with larger total length of CNA of breast cancers. Conclusions Thus, archival FFPE tissues from A-bomb survivors are useful for genome-wide aCGH analysis. Our results suggested that A-bomb radiation may affect the increased amount of CNA as a hallmark of GIN and, subsequently, be associated with a higher histologic grade in breast cancer found in A-bomb survivors.
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Affiliation(s)
- Masahiro Oikawa
- Department of Human Genetics, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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