Abstract
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.
Highlights
The phenomenon of «loss of heterozygosity» (LOH – loss of heterozygosity) is very often observed in tumor tissue
Further studies are needed to evaluate the frequency of BRCA1/2 LOH after neoadjuvant chemotherapy (NAC) for choosing and changing treatment tactics
We studied two regions of the long arm of chromosomes 13 and 17 (13q13.1 (BRCA2) and 17q21.31 (BRCA1), respectively) using the microarray analysis of LOH sites
Summary
The phenomenon of «loss of heterozygosity» (LOH – loss of heterozygosity) is very often observed in tumor tissue. Only in the case of the stage, in the form of the loss of the wild-type allele (directly the loss of heterozygosity), the process of cell malignancy occurs In this case, the loss of the allele makes it possible to manifest fatal recessive mutations, and in addition, activation of oncogenes and inactivation of tumor suppressor genes can occur, which leads to uncontrolled cell growth and metastasis [3, 4]. We studied two regions of the long arm of chromosomes 13 and 17 (13q13.1 (BRCA2) and 17q21.31 (BRCA1), respectively) using the microarray analysis of LOH sites
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
