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Letrozole sensitizes breast cancer cells to ionizing radiation
INTRODUCTION: Radiotherapy (RT) is considered a standard treatment option after surgery for breast cancer. Letrozole, an aromatase inhibitor, is being evaluated in the adjuvant setting. We determined the effects of the combination of RT and letrozole in the aromatase-expressing breast tumour cell li...
Autores principales: | , , , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2005
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1064115/ https://www.ncbi.nlm.nih.gov/pubmed/15642164 http://dx.doi.org/10.1186/bcr969 |
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author | Azria, David Larbouret, Christel Cunat, Severine Ozsahin, Mahmut Gourgou, Sophie Martineau, Pierre Evans, Dean B Romieu, Gilles Pujol, Pascal Pèlegrin, Andre |
author_facet | Azria, David Larbouret, Christel Cunat, Severine Ozsahin, Mahmut Gourgou, Sophie Martineau, Pierre Evans, Dean B Romieu, Gilles Pujol, Pascal Pèlegrin, Andre |
author_sort | Azria, David |
collection | PubMed |
description | INTRODUCTION: Radiotherapy (RT) is considered a standard treatment option after surgery for breast cancer. Letrozole, an aromatase inhibitor, is being evaluated in the adjuvant setting. We determined the effects of the combination of RT and letrozole in the aromatase-expressing breast tumour cell line MCF-7CA, stably transfected with the CYP19 gene. METHODS: Irradiations were performed using a cobalt-60 source with doses ranging from 0 to 4 Gy. Cells were incubated with androstenedione in the presence or absence of letrozole. Effects of treatment were evaluated using clonogenic assays, tetrazolium salt colorimetric (MTT) assays, and cell number determinations. Cell-cycle analyses were conducted using flow cytometry. RESULTS: The survival fraction at 2 Gy was 0.66 for RT alone and was 0.44 for RT plus letrozole (P = 0.02). Growth of MCF-7CA cells as measured by the cell number 6 days after radiotherapy (2 and 4 Gy) was decreased by 76% in those cells treated additionally with letrozole (0.7 μM) compared with those receiving radiotherapy alone (P = 0.009). Growth inhibition, assessed either by cell number (P = 0.009) or by the MTT assay (P = 0.02), was increased after 12 days of the combination treatment. Compared with radiation alone, the combination of radiation and letrozole produced a significant decrease in radiation-induced G(2 )phase arrest and a decrease of cells in the S phase, with cell redistribution in the G(1 )phase. CONCLUSIONS: These radiobiological results may form the basis for concurrent use of letrozole and radiation as postsurgical adjuvant therapy for breast cancer. |
format | Text |
id | pubmed-1064115 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2005 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-10641152005-03-11 Letrozole sensitizes breast cancer cells to ionizing radiation Azria, David Larbouret, Christel Cunat, Severine Ozsahin, Mahmut Gourgou, Sophie Martineau, Pierre Evans, Dean B Romieu, Gilles Pujol, Pascal Pèlegrin, Andre Breast Cancer Res Research Article INTRODUCTION: Radiotherapy (RT) is considered a standard treatment option after surgery for breast cancer. Letrozole, an aromatase inhibitor, is being evaluated in the adjuvant setting. We determined the effects of the combination of RT and letrozole in the aromatase-expressing breast tumour cell line MCF-7CA, stably transfected with the CYP19 gene. METHODS: Irradiations were performed using a cobalt-60 source with doses ranging from 0 to 4 Gy. Cells were incubated with androstenedione in the presence or absence of letrozole. Effects of treatment were evaluated using clonogenic assays, tetrazolium salt colorimetric (MTT) assays, and cell number determinations. Cell-cycle analyses were conducted using flow cytometry. RESULTS: The survival fraction at 2 Gy was 0.66 for RT alone and was 0.44 for RT plus letrozole (P = 0.02). Growth of MCF-7CA cells as measured by the cell number 6 days after radiotherapy (2 and 4 Gy) was decreased by 76% in those cells treated additionally with letrozole (0.7 μM) compared with those receiving radiotherapy alone (P = 0.009). Growth inhibition, assessed either by cell number (P = 0.009) or by the MTT assay (P = 0.02), was increased after 12 days of the combination treatment. Compared with radiation alone, the combination of radiation and letrozole produced a significant decrease in radiation-induced G(2 )phase arrest and a decrease of cells in the S phase, with cell redistribution in the G(1 )phase. CONCLUSIONS: These radiobiological results may form the basis for concurrent use of letrozole and radiation as postsurgical adjuvant therapy for breast cancer. BioMed Central 2005 2004-12-07 /pmc/articles/PMC1064115/ /pubmed/15642164 http://dx.doi.org/10.1186/bcr969 Text en Copyright © 2004 Azria et al., licensee BioMed Central Ltd. |
spellingShingle | Research Article Azria, David Larbouret, Christel Cunat, Severine Ozsahin, Mahmut Gourgou, Sophie Martineau, Pierre Evans, Dean B Romieu, Gilles Pujol, Pascal Pèlegrin, Andre Letrozole sensitizes breast cancer cells to ionizing radiation |
title | Letrozole sensitizes breast cancer cells to ionizing radiation |
title_full | Letrozole sensitizes breast cancer cells to ionizing radiation |
title_fullStr | Letrozole sensitizes breast cancer cells to ionizing radiation |
title_full_unstemmed | Letrozole sensitizes breast cancer cells to ionizing radiation |
title_short | Letrozole sensitizes breast cancer cells to ionizing radiation |
title_sort | letrozole sensitizes breast cancer cells to ionizing radiation |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1064115/ https://www.ncbi.nlm.nih.gov/pubmed/15642164 http://dx.doi.org/10.1186/bcr969 |
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