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Murillo-Ortiz BO, García-Corrales K, Martínez-Garza S, Romero-Vázquez MJ, Agustín-Godínez E, Escareño-Gómez A, Silva-Guerrero DG, Mendoza-Ramírez S, Murguia-Perez M. Association of hTERT expression, Her2Neu, estrogen receptors, progesterone receptors, with telomere length before and at the end of treatment in breast cancer patients. Front Med (Lausanne) 2024; 11:1450147. [PMID: 39188883 PMCID: PMC11345256 DOI: 10.3389/fmed.2024.1450147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Accepted: 07/29/2024] [Indexed: 08/28/2024] Open
Abstract
Background Breast cancer shows significant clinical, morphologic, and molecular variation. Telomeres are nucleoprotein complexes composed of hexanucleotide repeat DNA sequence, TTAGGG, and numerous telomere-associated proteins. The maintenance of telomere length is carried out by a ribonucleoprotein called telomerase, which consists of two main components: a catalytic subunit called hTERT (human telomerase reverse transcriptase) and an RNA template called hTR (human telomerase RNA). The importance of evaluating hTERT expression lies in its potential therapeutic application, being an attractive target due to its almost non-existent expression in normal somatic cells. It is also expected that the anti-neoplastic effect would appear earlier in neoplastic cells with shorter telomeres. Additionally, a significant relationship has been observed between Her2-Neu overexpression and Her2-Neu positivity, which could suggest new combined therapies.The aim of this study was to detect the expression of hTERT, estrogen receptor (ER), progesterone receptor (PR), and HER2-Neu in neoplastic breast tissue embedded in paraffin before treatment and to investigate the relationship between them and with baseline and post-treatment telomere length, as well as with various clinicopathological parameters. Materials and methods A cross-sectional-correlational, 21 women diagnosed with breast cancer at the Oncology Service of the High Specialty Medical Unit No. 1 of Bajio of the Mexican Institute of Social Security. The study complies with the Helsinki Declaration and was approved by the Institutional Ethical Committee of the Mexican Institute of Social Security (R-2019-1001-127). A peripheral blood sample was obtained before oncological treatment and at the end of oncological treatment for the measurement of telomere length by extracting DNA from leukocytes, was performed by the quantitative polymerase chain reaction (PCR) method described by Cawthon. Tumor samples were collected from each patient at the oncology department for immunohistochemical determination of biomarker expression (ER, PR, Her2/neu) and hTERT. Results Of the 21 cases included in the study, the median age was 57.57 years. Eighteen cases were classified as invasive ductal carcinoma NOS (85.71%), 10 were histologic grade 2 (47.61%), 16 cases were hormone receptor positive (76.19%), 7 were Her2Neu positive (33.33%), and only 2 cases were triple negative (9.52%). Positive hTERT expression was detected in 11 cases (52.38%) and was negative in the remaining cases. A significant association was identified between hTERT-positive cases and Her2-Neu positive cases (p = 0.04). Baseline and post-treatment telomere lengths showed a significant difference using the non-parametric Wilcoxon t-test (p = 0.002). In hTERT-positive cases, there was significant telomere shortening at the end of oncological treatment (6.14 ± 1.54 vs. 4.75 ± 1.96 Kb, p = 0.007). Conclusion Positive hTERT immunostaining cases were associated with poor prognostic factors, such as Her2-Neu overexpression and post-treatment telomere shortening. In the future, hTERT immunostaining could be used to select patients for therapies with antagonistic effects on hTERT, as well as in the selection of more appropriate chemotherapy regimens for patients who express it.
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Affiliation(s)
- Blanca Olivia Murillo-Ortiz
- Unidad de Investigación en Epidemiología Clínica, OOAD Guanajuato, Instituto Mexicano del Seguro Social, León, Mexico
| | - Kenia García-Corrales
- Servicio de Anatomía Patológica, Hospital General de Zona No. 33, Instituto Mexicano del Seguro Social, Bahía de Banderas, Mexico
| | - Sandra Martínez-Garza
- Unidad de Investigación en Epidemiología Clínica, OOAD Guanajuato, Instituto Mexicano del Seguro Social, León, Mexico
| | - Marcos Javier Romero-Vázquez
- Unidad de Investigación en Epidemiología Clínica, OOAD Guanajuato, Instituto Mexicano del Seguro Social, León, Mexico
| | - Eduardo Agustín-Godínez
- Laboratorio de Anatomía Patológica e Inmunohistoquímica Especializada DIME, Hospital Médica Campestre, León, Mexico
| | - Andrea Escareño-Gómez
- Departamento de Patología Quirúrgica, UMAE Hospital de Especialidades No. 1, Centro Médico Nacional Bajío, Instituto Mexicano del Seguro Social, León, Mexico
| | | | | | - Mario Murguia-Perez
- Laboratorio de Anatomía Patológica e Inmunohistoquímica Especializada DIME, Hospital Médica Campestre, León, Mexico
- Departamento de Patología Quirúrgica, UMAE Hospital de Especialidades No. 1, Centro Médico Nacional Bajío, Instituto Mexicano del Seguro Social, León, Mexico
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2
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Vicari MR, Bruschi DP, Cabral-de-Mello DC, Nogaroto V. Telomere organization and the interstitial telomeric sites involvement in insects and vertebrates chromosome evolution. Genet Mol Biol 2022; 45:e20220071. [DOI: 10.1590/1678-4685-gmb-2022-0071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 09/24/2022] [Indexed: 11/16/2022] Open
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3
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Aljarbou F, Almousa N, Bazzi M, Aldaihan S, Alanazi M, Alharbi O, Almadi M, Aljebreen AM, Azzam NA, Arafa M, Aldbass A, Shaik J, Alasirri S, Warsy A, Alamri A, Parine NR, Alamro G. The expression of telomere-related proteins and DNA damage response and their association with telomere length in colorectal cancer in Saudi patients. PLoS One 2018; 13:e0197154. [PMID: 29870526 PMCID: PMC5988329 DOI: 10.1371/journal.pone.0197154] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 04/27/2018] [Indexed: 01/04/2023] Open
Abstract
Background Colorectal cancer is the leading cause of cancer-related deaths in Saudi Arabia. Cancer has a multifactorial nature and can be described as a disease of altered gene expression. The profiling of gene expression has been used to identify cancer subtypes and to predict patients’ responsiveness. Telomere-associated proteins that regulate telomere biology are essential molecules in cancer development. Thus, the present study examined their contributions to colorectal cancer progression in Saudi patients. Methods The expression of hTERT, TRF1, TRF2, POT1, ATR, ATM, Chk1 and Chk2 were measured via real-time PCR in matched cancerous and adjacent tissues of CRC patients. The protein level of hTERT, TRF1, TRF2, ATR, ATM, Chk1 and Chk2 were measured using immunohistochemistry. A region of hTERT core promoter was sequenced via Sanger sequencing. Methylation of CTCF binding site was examined via methylation-specific PCR. Finally, the length of telomere was estimated using q-PCR. Results Our results showed that POT1, ATR, Chk1 and Chk2 show increased expression in CRC relative to the adjacent mucosa. The expression levels of each gene were associated with clinicopathological characteristics of patients with CRC. There was a positive correlation between the age of the patients and hTERT expression. Regarding tumor site, telomere length, ATR, ATM and Chk1 were shown to be altered. No somatic mutation was detected in hTERT core promoter, and no differences in methylation patterns at CTCF binding site in the promoter between normal and cancer tissues. Conclusion Analysis of targeted genes expression in colorectal cancer based on the clinical variables revealed that tumor location and age could have a role in gene expression and telomere length variations and this could be taken under consideration during CRC diagnosis and therapy. Other epigenetic mechanisms could influence hTERT expression in cancers. Our findings warrant further validation through experiments involving a larger number of patients.
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Affiliation(s)
- Ftoon Aljarbou
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
- * E-mail:
| | - Nourah Almousa
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Mohammad Bazzi
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Sooad Aldaihan
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed Alanazi
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Othman Alharbi
- Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - Majid Almadi
- Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - Abdulrahman M. Aljebreen
- Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - Nahla Ali Azzam
- Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - Maha Arafa
- Department of Histopathology, King Saud University, King Khalid University Hospital, Riyadh, Saudi Arabia
| | - Abeer Aldbass
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Jilani Shaik
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Shaheerah Alasirri
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Arjumand Warsy
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah Alamri
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Narasimha Reddy Parine
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Ghadah Alamro
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
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4
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Lebya K, Garcia‐Smith R, Swaminathan R, Jones A, Russell J, Joste N, Bisoffi M, Trujillo K. Towards a personalized surgical margin for breast conserving surgery—Implications of field cancerization in local recurrence. J Surg Oncol 2017; 115:109-115. [DOI: 10.1002/jso.24469] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 09/19/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Katarina Lebya
- Department of Cell Biology and PhysiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNew Mexico
| | - Randi Garcia‐Smith
- Department of Cell Biology and PhysiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNew Mexico
| | | | - Anna Jones
- Department of Internal MedicineUniversity of New Mexico Health Science CenterAlbuquerqueNew Mexico
| | - John Russell
- Department of SurgeryUniversity of New Mexico Health Science CenterAlbuquerqueNew Mexico
| | - Nancy Joste
- Department of PathologyUniversity of New Mexico Health Science CenterAlbuquerqueNew Mexico
| | - Marco Bisoffi
- Biochemistry and Molecular BiologySchmid College of Science and Technology Chapman UniversityOrangeCalifornia
| | - Kristina Trujillo
- Department of Cell Biology and PhysiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNew Mexico
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5
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Khattar E, Kumar P, Liu CY, Akıncılar SC, Raju A, Lakshmanan M, Maury JJP, Qiang Y, Li S, Tan EY, Hui KM, Shi M, Loh YH, Tergaonkar V. Telomerase reverse transcriptase promotes cancer cell proliferation by augmenting tRNA expression. J Clin Invest 2016; 126:4045-4060. [PMID: 27643433 DOI: 10.1172/jci86042] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 08/11/2016] [Indexed: 12/13/2022] Open
Abstract
Transcriptional reactivation of telomerase reverse transcriptase (TERT) reconstitutes telomerase activity in the majority of human cancers. Here, we found that ectopic TERT expression increases cell proliferation, while acute reductions in TERT levels lead to a dramatic loss of proliferation without any change in telomere length, suggesting that the effects of TERT could be telomere independent. We observed that TERT determines the growth rate of cancer cells by directly regulating global protein synthesis independently of its catalytic activity. Genome-wide TERT binding across 5 cancer cell lines and 2 embryonic stem cell lines revealed that endogenous TERT, driven by mutant promoters or oncogenes, directly associates with the RNA polymerase III (pol III) subunit RPC32 and enhances its recruitment to chromatin, resulting in increased RNA pol III occupancy and tRNA expression in cancers. TERT-deficient mice displayed marked delays in polyomavirus middle T oncogene-induced (PyMT-induced) mammary tumorigenesis, increased survival, and reductions in tRNA levels. Ectopic expression of either RPC32 or TERT restored tRNA levels and proliferation defects in TERT-depleted cells. Finally, we determined that levels of TERT and tRNA correlated in breast and liver cancer samples. Together, these data suggest the existence of a unifying mechanism by which TERT enhances translation in cells to regulate cancer cell proliferation.
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MESH Headings
- Animals
- Cell Line, Tumor
- Cell Proliferation
- Cell Transformation, Neoplastic/metabolism
- Female
- Gene Expression Regulation, Neoplastic
- HEK293 Cells
- Humans
- Mammary Neoplasms, Experimental/enzymology
- Mammary Neoplasms, Experimental/pathology
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Knockout
- Mice, SCID
- Neoplasm Transplantation
- Promoter Regions, Genetic
- Protein Binding
- Protein Biosynthesis
- Protein Interaction Domains and Motifs
- RNA Polymerase III/metabolism
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Telomerase/physiology
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6
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Danforth DN. Genomic Changes in Normal Breast Tissue in Women at Normal Risk or at High Risk for Breast Cancer. BREAST CANCER-BASIC AND CLINICAL RESEARCH 2016; 10:109-46. [PMID: 27559297 PMCID: PMC4990153 DOI: 10.4137/bcbcr.s39384] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/17/2016] [Accepted: 04/19/2016] [Indexed: 12/12/2022]
Abstract
Sporadic breast cancer develops through the accumulation of molecular abnormalities in normal breast tissue, resulting from exposure to estrogens and other carcinogens beginning at adolescence and continuing throughout life. These molecular changes may take a variety of forms, including numerical and structural chromosomal abnormalities, epigenetic changes, and gene expression alterations. To characterize these abnormalities, a review of the literature has been conducted to define the molecular changes in each of the above major genomic categories in normal breast tissue considered to be either at normal risk or at high risk for sporadic breast cancer. This review indicates that normal risk breast tissues (such as reduction mammoplasty) contain evidence of early breast carcinogenesis including loss of heterozygosity, DNA methylation of tumor suppressor and other genes, and telomere shortening. In normal tissues at high risk for breast cancer (such as normal breast tissue adjacent to breast cancer or the contralateral breast), these changes persist, and are increased and accompanied by aneuploidy, increased genomic instability, a wide range of gene expression differences, development of large cancerized fields, and increased proliferation. These changes are consistent with early and long-standing exposure to carcinogens, especially estrogens. A model for the breast carcinogenic pathway in normal risk and high-risk breast tissues is proposed. These findings should clarify our understanding of breast carcinogenesis in normal breast tissue and promote development of improved methods for risk assessment and breast cancer prevention in women.
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Affiliation(s)
- David N Danforth
- Surgery Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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7
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Butler KS, Hines WC, Heaphy CM, Griffith JK. Coordinate regulation between expression levels of telomere-binding proteins and telomere length in breast carcinomas. Cancer Med 2012; 1:165-75. [PMID: 23342266 PMCID: PMC3544452 DOI: 10.1002/cam4.14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 05/15/2012] [Accepted: 06/01/2012] [Indexed: 02/02/2023] Open
Abstract
Telomere dysregulation occurs in both the in situ and invasive stages of many carcinomas, including breast. Knockout experiments have identified several telomere-associated proteins required for proper telomere function and maintenance, including telomere repeat-binding factor 1 and 2 (TRF1 and TRF2), protection of telomeres (POT1), and TRF1-interacting nuclear factor 2 (TIN2). Using telomere content assays and quantitative reverse transcription-polymerase chain reaction (RT-PCR), we examined the relationship between telomere length and the mRNA levels of telomere-associated proteins in breast tumors. The levels of TRF2, TRF1, TIN2, and POT1 mRNA, but not telomerase reverse transcriptase (TERT) RNA, are inversely correlated with telomere content in breast tumors. Significant associations were identified between the mRNA levels of TRF1, TIN2, and POT1; however, there were no significant associations with the mRNA levels of TRF2 or TERT. These associations suggest that a complex transcriptional program coordinately regulates the expression of these mRNAs. We examined the promoter regions of the telomere-associated proteins to identify transcription factors consistent with the observed patterns of presumed coordinate expression. We demonstrated in human breast cancer cell lines that expressions of TRF1, TIN2, and POT1 are upregulated by dexamethasone, suggesting activation of the glucocorticoid receptor, whereas TERT, TRF2, TRF1, TIN2, and POT1 are upregulated by tumor necrosis factor-α (TNF-α), suggesting activation of the nuclear factor kappa B transcription factor. These findings link telomere content in breast tumors to the coordinate expression of several telomere-associated proteins previously shown to be negative regulators of telomere length in cell lines. The results further suggest a possible link between the expressions of the telomere-associated proteins and mediators of stress and inflammation. Telomere content assays and quantitative RT-PCR demonstrate that the levels of TRF2, TRF1, TIN2, and POT1 mRNA, but not telomerase reverse transcriptase (TERT) RNA, are inversely correlated with telomere content in breast tumors. Within human breast cancer cell lines, expressions of TRF1, TIN2, and POT1 are upregulated by dexamethasone, suggesting activation of the glucocorticoid receptor, whereas TERT, TRF2, TRF1, TIN2, and POT1 are upregulated by TNF-α, suggesting activation of the NFκB transcription factor. These findings link telomere content in breast tumors to the expression of several telomere-associated proteins previously shown to be negative regulators of telomere length in cell lines and suggest a link between the expressions of the telomere-associated proteins and mediators of stress and inflammation.
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Affiliation(s)
- Kimberly S Butler
- Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine Albuquerque, New Mexico, 87131, USA
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8
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Aging Process in Chromatin of Animals. ANNALS OF ANIMAL SCIENCE 2012. [DOI: 10.2478/v10220-012-0025-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aging Process in Chromatin of AnimalsThe aging process is a variable, stochastic and pleiotropic phenomenon which is regulated by different environmental and genetic factors. The age-associated changes, which occur at the molecular and cellular levels and disturb biological homeostasis, may directly or indirectly contribute to aging, causing apoptosis or cellular senescence and consequently leading to the death of the organism. In this context, it is particularly interesting to observe changes in somatic cell chromatin. In the present paper, we summarized the knowledge on the biological aspects of aging with special consideration of age-related changes in chromatin like DNA damage, shortening telomeres or age-related changes in methylation of DNA.
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9
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Abstract
MYC is a key regulator of cell growth, proliferation, metabolism, differentiation, and apoptosis. MYC deregulation contributes to breast cancer development and progression and is associated with poor outcomes. Multiple mechanisms are involved in MYC deregulation in breast cancer, including gene amplification, transcriptional regulation, and mRNA and protein stabilization, which correlate with loss of tumor suppressors and activation of oncogenic pathways. The heterogeneity in breast cancer is increasingly recognized. Breast cancer has been classified into 5 or more subtypes based on gene expression profiles, and each subtype has distinct biological features and clinical outcomes. Among these subtypes, basal-like tumor is associated with a poor prognosis and has a lack of therapeutic targets. MYC is overexpressed in the basal-like subtype and may serve as a target for this aggressive subtype of breast cancer. Tumor suppressor BRCA1 inhibits MYC's transcriptional and transforming activity. Loss of BRCA1 with MYC overexpression leads to the development of breast cancer-especially, basal-like breast cancer. As a downstream effector of estrogen receptor and epidermal growth factor receptor family pathways, MYC may contribute to resistance to adjuvant therapy. Targeting MYC-regulated pathways in combination with inhibitors of other oncogenic pathways may provide a promising therapeutic strategy for breast cancer, the basal-like subtype in particular.
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Affiliation(s)
- Jinhua Xu
- Center for Clinical Cancer Genetics, Department of Medicine, University of Chicago, Chicago, IL, USA
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10
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Trujillo KA, Hines WC, Vargas KM, Jones AC, Joste NE, Bisoffi M, Griffith JK. Breast field cancerization: isolation and comparison of telomerase-expressing cells in tumor and tumor adjacent, histologically normal breast tissue. Mol Cancer Res 2011; 9:1209-21. [PMID: 21775421 DOI: 10.1158/1541-7786.mcr-10-0424] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Telomerase stabilizes chromosomes by maintaining telomere length, immortalizes mammalian cells, and is expressed in more than 90% of human tumors. However, the expression of human telomerase reverse transcriptase (hTERT) is not restricted to tumor cells. We have previously shown that a subpopulation of human mammary epithelial cells (HMEC) in tumor-adjacent, histologically normal (TAHN) breast tissues expresses hTERT mRNA at levels comparable with levels in breast tumors. In the current study, we first validated a reporter for measuring levels of hTERT promoter activity in early-passage HMECs and then used this reporter to compare hTERT promoter activity in HMECs derived from tumor and paired TAHN tissues 1, 3, and 5 cm from the tumor (TAHN-1, TAHN-3, and TAHN-5, respectively). Cell sorting, quantitative real-time PCR, and microarray analyses showed that the 10% of HMECs with the highest hTERT promoter activity in both tumor and TAHN-1 tissues contain more than 95% of hTERT mRNA and overexpress many genes involved in cell cycle and mitosis. The percentage of HMECs within this subpopulation showing high hTERT promoter activity was significantly reduced or absent in TAHN-3 and TAHN-5 tissues. We conclude that the field of "normal tissue" proximal to the breast tumors contains a population of HMECs similar in hTERT expression levels and in gene expression to the HMECs within the tumor mass and that this population is significantly reduced in tissues more distal to the tumor.
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Affiliation(s)
- Kristina A Trujillo
- Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, MSC08 4670 Albuquerque, New Mexico 87131, USA
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11
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Trujillo KA, Heaphy CM, Mai M, Vargas KM, Jones AC, Vo P, Butler KS, Joste NE, Bisoffi M, Griffith JK. Markers of fibrosis and epithelial to mesenchymal transition demonstrate field cancerization in histologically normal tissue adjacent to breast tumors. Int J Cancer 2011; 129:1310-21. [PMID: 21105047 DOI: 10.1002/ijc.25788] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 10/25/2010] [Indexed: 12/24/2022]
Abstract
Previous studies have shown that a field of genetically altered but histologically normal tissue extends 1 cm or more from the margins of human breast tumors. The extent, composition and biological significance of this field are only partially understood, but the molecular alterations in affected cells could provide mechanisms for limitless replicative capacity, genomic instability and a microenvironment that supports tumor initiation and progression. We demonstrate by microarray, qRT-PCR and immunohistochemistry a signature of differential gene expression that discriminates between patient-matched, tumor-adjacent histologically normal breast tissues located 1 cm and 5 cm from the margins of breast adenocarcinomas (TAHN-1 and TAHN-5, respectively). The signature includes genes involved in extracellular matrix remodeling, wound healing, fibrosis and epithelial to mesenchymal transition (EMT). Myofibroblasts, which are mediators of wound healing and fibrosis, and intra-lobular fibroblasts expressing MMP2, SPARC, TGF-β3, which are inducers of EMT, were both prevalent in TAHN-1 tissues, sparse in TAHN-5 tissues, and absent in normal tissues from reduction mammoplasty. Accordingly, EMT markers S100A4 and vimentin were elevated in both luminal and myoepithelial cells, and EMT markers α-smooth muscle actin and SNAIL were elevated in luminal epithelial cells of TAHN-1 tissues. These results identify cellular processes that are differentially activated between TAHN-1 and TAHN-5 breast tissues, implicate myofibroblasts as likely mediators of these processes, provide evidence that EMT is occurring in histologically normal tissues within the affected field and identify candidate biomarkers to investigate whether or how field cancerization contributes to the development of primary or recurrent breast tumors.
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Affiliation(s)
- Kristina A Trujillo
- Department of Biochemistry and Molecular Biology, MSC08 4670 University of New Mexico, Albuquerque, NM 87173, USA
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12
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Bazarov AV, van Sluis M, Hines C, Bassett E, Beliveau A, Campeau E, Mukhopadhyay R, Lee WJ, Melodyev S, Zaslavsky Y, Lee L, Rodier F, Chicas A, Lowe SW, Benhattar J, Ren B, Campisi J, Yaswen P. p16(INK4a) -mediated suppression of telomerase in normal and malignant human breast cells. Aging Cell 2010; 9:736-46. [PMID: 20569236 PMCID: PMC2941554 DOI: 10.1111/j.1474-9726.2010.00599.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The cyclin-dependent kinase inhibitor p16(INK4a) (CDKN2A) is an important tumor suppressor gene frequently inactivated in human tumors. p16 suppresses the development of cancer by triggering an irreversible arrest of cell proliferation termed cellular senescence. Here, we describe another anti-oncogenic function of p16 in addition to its ability to halt cell cycle progression. We show that transient expression of p16 stably represses the hTERT gene, encoding the catalytic subunit of telomerase, in both normal and malignant breast epithelial cells. Short-term p16 expression increases the amount of histone H3 trimethylated on lysine 27 (H3K27) bound to the hTERT promoter, resulting in transcriptional silencing, likely mediated by polycomb complexes. Our results indicate that transient p16 exposure may prevent malignant progression in dividing cells by irreversible repression of genes, such as hTERT, whose activity is necessary for extensive self-renewal.
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Affiliation(s)
- Alexey V. Bazarov
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Marjolein van Sluis
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Curtis Hines
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Ekaterina Bassett
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alain Beliveau
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Eric Campeau
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Won Jae Lee
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sonya Melodyev
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yuri Zaslavsky
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Leonard Lee
- Ludwig Institute For Cancer Research, University of California, San Diego, CA, USA
| | - Francis Rodier
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Buck Institute for Age Research, Novato, CA, USA
| | - Agustin Chicas
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Scott W. Lowe
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Jean Benhattar
- Institute of Pathology, University of Lausanne, 1011 Lausanne, Switzerland
| | - Bing Ren
- Ludwig Institute For Cancer Research, University of California, San Diego, CA, USA
| | - Judith Campisi
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Buck Institute for Age Research, Novato, CA, USA
| | - Paul Yaswen
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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13
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Mammary field cancerization: molecular evidence and clinical importance. Breast Cancer Res Treat 2009; 118:229-39. [PMID: 19685287 DOI: 10.1007/s10549-009-0504-0] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 08/03/2009] [Indexed: 12/27/2022]
Abstract
The term "field cancerization" originally denoted the presence of histologically abnormal tissue/cells surrounding primary tumors of the head and neck. Similar concepts with different and continuously changing definitions have been used for other types of tumors including breast adenocarcinoma, where field cancerization presently denotes the occurrence of molecular alterations in histologically normal tissues surrounding areas of overt cancer. Human mammary tissue morphology lends itself to the proposed concepts of field cancerization, which may include the gradual accumulation of genetic and other aberrations in stationary epithelial cells with intact morphology, or the spread of histologically normal yet genetically aberrant epithelial cells within mammary tissue. In this report, we review published molecular genetic, epigenetic, and gene expressional data in support of field cancerization in human mammary tissues. We then discuss the clinical implications of mammary field cancerization, including its source for potential biomarkers with diagnostic/prognostic potential, and its relationship to surgical margins and disease recurrence. We conclude with a future outlook on further research on mammary field cancerization addressing experimental methods, as well as the development of possible models and integrated approaches to gain a better understanding of the underlying mechanisms with the ultimate goal of developing clinical applications.
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Abstract
Breast cancer is the second leading cause of cancer deaths and is the most frequently diagnosed cancer in women of industrialized nations. Breast cancer progression is a multistep process involving genetic and epigenetic alterations that drive normal breast cells into highly malignant derivatives with metastatic potential. MYC is a proto-oncogene whose protein product contains a basic helix-loop-helix domain. MYC functions as a transcription factor regulating up to 15% of all human genes. MYC is regulated at multiple levels, and the protein is a downstream effector of several signaling pathways. In breast cancer cells, MYC target genes are involved in cell growth, transformation, angiogenesis and cell-cycle control. BRCA1 is linked to transcriptional regulation through interaction with MYC. Although the relationship between amplification and overexpression is not clearly delineated, MYC amplification is significantly correlated with aggressive tumor phenotypes and poor clinical outcomes. MYC amplification is emerging as an important predictor of response to HER2-targeted therapies and its role in BRCA1-associated breast cancer makes it an important target in basal-like/triple-negative breast cancers.
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Affiliation(s)
- Yinghua Chen
- Department of Medicine, Center for Clinical Cancer Genetics, University of Chicago, Chicago, IL 60637, USA.
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Poonepalli A, Banerjee B, Ramnarayanan K, Palanisamy N, Putti TC, Hande MP. Telomere-mediated genomic instability and the clinico-pathological parameters in breast cancer. Genes Chromosomes Cancer 2008; 47:1098-109. [DOI: 10.1002/gcc.20608] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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16
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Genomic instability demonstrates similarity between DCIS and invasive carcinomas. Breast Cancer Res Treat 2008; 117:17-24. [PMID: 18785004 DOI: 10.1007/s10549-008-0165-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 08/14/2008] [Indexed: 12/13/2022]
Abstract
PURPOSE To assess telomere DNA content (TC) and the number of sites of allelic imbalance (AI) as a function of breast cancer progression. EXPERIMENTAL DESIGN TC and AI were determined in 54 histologically normal tissues, 10 atypical ductal hyperplasias (ADH), 122 in situ ductal carcinomas (DCIS) and 535 invasive carcinomas (Stage I-IIIA). RESULTS TC was altered in ADH lesions (20%), DCIS specimens (53%) and invasive carcinomas (51%). The mean number of sites of AI was 0.26 in histologically normal group tissue, increased to 1.00 in ADH, 2.94 in DCIS, and 3.07 in invasive carcinomas. All groups were statistically different from the histologically normal group (P < 0.001 for each); however, there was no difference between DCIS and the invasive groups. CONCLUSIONS Genomic instability increases in ADH and plateaus in DCIS without further increase in the invasive carcinomas, supporting the notion that invasive carcinomas evolve from or in parallel with DCIS.
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Molecular characterisation of breast cancer patients at high and low recurrence risk. Virchows Arch 2008; 452:241-50. [DOI: 10.1007/s00428-007-0570-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 10/23/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
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18
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Abstract
Telomeres are required to preserve genome integrity, chromosome stability, nuclear architecture and chromosome pairing during meiosis. Given that telomerase activity is limiting or absent in most somatic tissues, shortening of telomeres during development and aging is the rule. In vitro, telomere length operates as a mechanism to prevent uncontrolled cell growth and therefore defines the proliferation potential of a cell. In vitro, in somatic cells that have lost proliferation control, shortening of telomeres becomes the main source of genome instability leading to genetic or epigenetic changes that may allow cells to become immortal and to acquire tumor phenotypes. In vivo, mice models have indisputably shown both the protective and the promoting role of very short telomeres in cancer development. In humans, although telomere shortening and other types of telomere dysfunction probably contribute to the genome instability often detected in tumors, the specific contributions of such instability to the development of cancer remain largely undetermined.
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Abstract
It was in the 1930s that telomeres (from the Greek telos = end and meros = part) were first recognized as essential structures at the ends of the chromosomes and were shown to be important for chromosomal stability (Muller HJ: The remaking of chromosomes. The Collecting Net-Woods Hole 1938: 13: 181-198, McClintock B, The stability of broken ends of chromosomes in Zea mays. Genetics 1041: 26: 234-282). However, it was only in 1978 that the first telomeric sequence was identified -- in the protocoa Tetrahymena, a single cell organism that at a certain stage of development has many identical minichromosomes with twice as many telomeres (Blackburn EH and Gall JG. A tandemly repeated sequence at the termini of the extrachromosomal ribosomal RNA genes in Tetrahymena. J. Mol. Biol. 1978: 120: 33-53.). Today we know that telomeres form specialized, three-dimensional DNA-protein structures and fulfil important capping functions. Besides, telomeric DNA is essential as ''access DNA'' for those cells that are not able to counteract loss of DNA during replication because they do not express telomerase, the enzyme responsible for telomere length maintenance. Since telomerase is mostly found in tumor cells and inhibition correlates with telomere shortening and finally growth inhibition, telomerase and lately also the telomeres themselves have become attractive targets for anti-cancer therapy. This review aims to critically throw light on different therapeutical approaches and comes to the conclusion that telomeres may be the better targets for cancer therapeutics.
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Affiliation(s)
- Petra Boukamp
- Department of Genetics and Skin Carcinogenesis, German Cancer Research Center, Heidelberg, Germany.
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20
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Murillo-Ortiz B, Astudillo-De la Vega H, Castillo-Medina S, Malacara JM, Benitez-Bribiesca L. Telomerase activity, estrogen receptors (alpha, beta), Bcl-2 expression in human breast cancer and treatment response. BMC Cancer 2006; 6:206. [PMID: 16911782 PMCID: PMC1562436 DOI: 10.1186/1471-2407-6-206] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Accepted: 08/15/2006] [Indexed: 11/23/2022] Open
Abstract
Background The mechanism for maintaining telomere integrity is controlled by telomerase, a ribonucleoprotein enzyme that specifically restores telomere sequences, lost during replication by means of an intrinsic RNA component as a template for polymerization. Among the telomerase subunits, hTERT (human telomerase reverse transcriptase) is expressed concomitantly with the activation of telomerase. The role of estrogens and their receptors in the transcriptional regulation of hTERT has been demonstrated. The current study determines the possible association between telomerase activity, the expression of both molecular forms of estrogen receptor (ERα and ERβ) and the protein bcl-2, and their relative associations with clinical parameters. Methods Tissue samples from 44 patients with breast cancer were used to assess telomerase activity using the TRAP method and the expression of ERα, ERβ and bcl-2 by means of immunocytochemical techniques. Results Telomerase activity was detected in 59% of the 44 breast tumors examined. Telomerase activity ranged from 0 to 49.93 units of total product generated (TPG). A correlation was found between telomerase activity and differentiation grade (p = 0.03). The only significant independent marker of response to treatment was clinical stage. We found differences between the frequency of expression of ERα (88%) and ERβ (36%) (p = 0.007); bcl-2 was expressed in 79.5% of invasive breast carcinomas. We also found a significant correlation between low levels of telomerase activity and a lack of ERβ expression (p = 0.03). Conclusion Lower telomerase activity was found among tumors that did not express estrogen receptor beta. This is the first published study demonstrating that the absence of expression of ERβ is associated with low levels of telomerase activity.
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Affiliation(s)
| | - Horacio Astudillo-De la Vega
- Unidad de Investigacion Medica en Enfermedades Oncologicas, Centro Medico Nacional Siglo XXI, IMSS, CP 06720, DF, México
| | - Sebastian Castillo-Medina
- Unidad de Investigacion Medica en Enfermedades Oncologicas, Centro Medico Nacional Siglo XXI, IMSS, CP 06720, DF, México
| | - JM Malacara
- Instituto de Investigaciones Medicas, Universidad de Guanajuato, Mexico
| | - Luis Benitez-Bribiesca
- Unidad de Investigacion Medica en Enfermedades Oncologicas, Centro Medico Nacional Siglo XXI, IMSS, CP 06720, DF, México
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Bolzán AD, Bianchi MS. Telomeres, interstitial telomeric repeat sequences, and chromosomal aberrations. Mutat Res 2006; 612:189-214. [PMID: 16490380 DOI: 10.1016/j.mrrev.2005.12.003] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 12/29/2005] [Accepted: 12/30/2005] [Indexed: 11/18/2022]
Abstract
Telomeres are specialized nucleoproteic complexes localized at the physical ends of linear eukaryotic chromosomes that maintain their stability and integrity. The DNA component of telomeres is characterized by being a G-rich double stranded DNA composed by short fragments tandemly repeated with different sequences depending on the species considered. At the chromosome level, telomeres or, more properly, telomeric repeats--the DNA component of telomeres--can be detected either by using the fluorescence in situ hybridization (FISH) technique with a DNA or a peptide nucleic acid (PNA) (pan)telomeric probe, i.e., which identifies simultaneously all of the telomeres in a metaphase cell, or by the primed in situ labeling (PRINS) reaction using an oligonucleotide primer complementary to the telomeric DNA repeated sequence. Using these techniques, incomplete chromosome elements, acentric fragments, amplification and translocation of telomeric repeat sequences, telomeric associations and telomeric fusions can be identified. In addition, chromosome orientation (CO)-FISH allows to discriminate between the different types of telomeric fusions, namely telomere-telomere and telomere-DNA double strand break fusions and to detect recombination events at the telomere, i.e., telomeric sister-chromatid exchanges (T-SCE). In this review, we summarize our current knowledge of chromosomal aberrations involving telomeres and interstitial telomeric repeat sequences and their induction by physical and chemical mutagens. Since all of the studies on the induction of these types of aberrations were conducted in mammalian cells, the review will be focused on the chromosomal aberrations involving the TTAGGG sequence, i.e., the telomeric repeat sequence that "caps" the chromosomes of all vertebrate species.
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Affiliation(s)
- Alejandro D Bolzán
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE), C.C. 403, 1900 La Plata, Argentina.
| | - Martha S Bianchi
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE), C.C. 403, 1900 La Plata, Argentina
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Heaphy CM, Bisoffi M, Fordyce CA, Haaland CM, Hines WC, Joste NE, Griffith JK. Telomere DNA content and allelic imbalance demonstrate field cancerization in histologically normal tissue adjacent to breast tumors. Int J Cancer 2006; 119:108-16. [PMID: 16450377 DOI: 10.1002/ijc.21815] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cancer arises from an accumulation of mutations that promote the selection of cells with progressively malignant phenotypes. Previous studies have shown that genomic instability, a hallmark of cancer cells, is a driving force in this process. In the present study, two markers of genomic instability, telomere DNA content and allelic imbalance, were examined in two independent cohorts of mammary carcinomas. Altered telomeres and unbalanced allelic loci were present in both tumors and surrounding histologically normal tissues at distances at least 1 cm from the visible tumor margins. Although the extent of these genetic changes decreases as a function of the distance from the visible tumor margin, unbalanced loci are conserved between the surrounding tissues and the tumors, implying cellular clonal evolution. Our results are in agreement with the concepts of "field cancerization" and "cancer field effect," concepts that were previously introduced to describe areas within tissues consisting of histologically normal, yet genetically aberrant, cells that represent fertile grounds for tumorigenesis. The finding that genomic instability occurs in fields of histologically normal tissues surrounding the tumor is of clinical importance, as it has implications for the definition of appropriate tumor margins and the assessment of recurrence risk factors in the context of breast-sparing surgery.
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Affiliation(s)
- Christopher M Heaphy
- Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, NM 87131-0001, USA
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