LOSS OF HETEROZYGOSITY IN THE BRCA1 AND BRCA2 LOCUS IN BREAST CANCER

One of the factors of variability of malignant neoplasms is the loss of heterozygosity (LOH). The biological meaning of LOH, in relation to carcinogenesis, is associated with the inactivation of heterozygous loci of pathogenetically significant genes. Thus, the aim of this work was to study BRCA1/2...

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Main Authors: M. M. Tsyganov, M. K. Ibragimova, A. M. Pevzner, N. V. Litviakov
Format: Article
Language:Russian
Published: Russian Academy of Sciences, Tomsk National Research Medical Center 2020-07-01
Series:Сибирский онкологический журнал
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Online Access:https://www.siboncoj.ru/jour/article/view/1492
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author M. M. Tsyganov
M. K. Ibragimova
A. M. Pevzner
N. V. Litviakov
author_facet M. M. Tsyganov
M. K. Ibragimova
A. M. Pevzner
N. V. Litviakov
author_sort M. M. Tsyganov
collection DOAJ
description One of the factors of variability of malignant neoplasms is the loss of heterozygosity (LOH). The biological meaning of LOH, in relation to carcinogenesis, is associated with the inactivation of heterozygous loci of pathogenetically significant genes. Thus, the aim of this work was to study BRCA1/2 LOH in breast tumors.Material and Methods. The study included 122 patients with stage IIAIIIC breast cancer. DNA was isolated from 122 biopsy samples of tumor tissue using the QIAamp DNA mini Kit (Qiagen, Germany). To assess the status of LOH, microarray analysis was performed on high-density DNA chips from Affymetrix CytoScanTM HD Array. To process the results of microchipping, we used the Chromosome Analysis Suite 3.3 program (Affymetrix, USA).Results. The loss of heterozygosity in the BRCA1 gene was found to be associated with response to NAC. It was shown that in 59 patients LOH in the BRCA1gene was associated with an objective response to treatment (p=0.005). The presence of LOH in the studied genes was associated with a favorable prognosis. The 5-year non-metastatic survival rates were 75 % and 100 % in patients with LOH in the BRCA1 and BRCA2 genes, respectively (log-rank test: p=0.003 and p=0.05, respectively).Conclusion. The phenomenon of LOH in the BRCA1/2 genes was shown to be associated with response to NACT. BRCA1/2. Further studies are needed to evaluate the frequency of BRCA1/2 LOH after NAC for choosing and changing treatment tactics.
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publisher Russian Academy of Sciences, Tomsk National Research Medical Center
record_format Article
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spelling doaj-art-cc9785d46f70442e97d099b4250645422025-08-20T03:56:24ZrusRussian Academy of Sciences, Tomsk National Research Medical CenterСибирский онкологический журнал1814-48612312-31682020-07-011939710110.21294/1814-4861-2020-19-3-97-101751LOSS OF HETEROZYGOSITY IN THE BRCA1 AND BRCA2 LOCUS IN BREAST CANCERM. M. Tsyganov0M. K. Ibragimova1A. M. Pevzner2N. V. Litviakov3Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of SciencesCancer Research Institute, Tomsk National Research Medical Center, Russian Academy of SciencesCancer Research Institute, Tomsk National Research Medical Center, Russian Academy of SciencesCancer Research Institute, Tomsk National Research Medical Center, Russian Academy of SciencesOne of the factors of variability of malignant neoplasms is the loss of heterozygosity (LOH). The biological meaning of LOH, in relation to carcinogenesis, is associated with the inactivation of heterozygous loci of pathogenetically significant genes. Thus, the aim of this work was to study BRCA1/2 LOH in breast tumors.Material and Methods. The study included 122 patients with stage IIAIIIC breast cancer. DNA was isolated from 122 biopsy samples of tumor tissue using the QIAamp DNA mini Kit (Qiagen, Germany). To assess the status of LOH, microarray analysis was performed on high-density DNA chips from Affymetrix CytoScanTM HD Array. To process the results of microchipping, we used the Chromosome Analysis Suite 3.3 program (Affymetrix, USA).Results. The loss of heterozygosity in the BRCA1 gene was found to be associated with response to NAC. It was shown that in 59 patients LOH in the BRCA1gene was associated with an objective response to treatment (p=0.005). The presence of LOH in the studied genes was associated with a favorable prognosis. The 5-year non-metastatic survival rates were 75 % and 100 % in patients with LOH in the BRCA1 and BRCA2 genes, respectively (log-rank test: p=0.003 and p=0.05, respectively).Conclusion. The phenomenon of LOH in the BRCA1/2 genes was shown to be associated with response to NACT. BRCA1/2. Further studies are needed to evaluate the frequency of BRCA1/2 LOH after NAC for choosing and changing treatment tactics.https://www.siboncoj.ru/jour/article/view/1492breast cancerbrca1 and brca2 mutation in the tumorloss of heterozygositymicroarray analysispersonalized medicine
spellingShingle M. M. Tsyganov
M. K. Ibragimova
A. M. Pevzner
N. V. Litviakov
LOSS OF HETEROZYGOSITY IN THE BRCA1 AND BRCA2 LOCUS IN BREAST CANCER
Сибирский онкологический журнал
breast cancer
brca1 and brca2 mutation in the tumor
loss of heterozygosity
microarray analysis
personalized medicine
title LOSS OF HETEROZYGOSITY IN THE BRCA1 AND BRCA2 LOCUS IN BREAST CANCER
title_full LOSS OF HETEROZYGOSITY IN THE BRCA1 AND BRCA2 LOCUS IN BREAST CANCER
title_fullStr LOSS OF HETEROZYGOSITY IN THE BRCA1 AND BRCA2 LOCUS IN BREAST CANCER
title_full_unstemmed LOSS OF HETEROZYGOSITY IN THE BRCA1 AND BRCA2 LOCUS IN BREAST CANCER
title_short LOSS OF HETEROZYGOSITY IN THE BRCA1 AND BRCA2 LOCUS IN BREAST CANCER
title_sort loss of heterozygosity in the brca1 and brca2 locus in breast cancer
topic breast cancer
brca1 and brca2 mutation in the tumor
loss of heterozygosity
microarray analysis
personalized medicine
url https://www.siboncoj.ru/jour/article/view/1492
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AT mkibragimova lossofheterozygosityinthebrca1andbrca2locusinbreastcancer
AT ampevzner lossofheterozygosityinthebrca1andbrca2locusinbreastcancer
AT nvlitviakov lossofheterozygosityinthebrca1andbrca2locusinbreastcancer