scholarly journals Loss of heterozygosity in CHEK2-associated breast cancer

2021 ◽  
Vol 67 (5) ◽  
pp. 658-664
Author(s):  
Svetlana Aleksakhina ◽  
Aglaya Ievleva ◽  
Anna Sokolenko ◽  
Sofia Baskina ◽  
Ajgul Venina ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Loss Of Heterozygosity ◽  
Significant Proportion ◽  
Nucleotide Polymorphisms ◽  
Breast Carcinomas ◽  
Digital Droplet Pcr ◽  
Specific Pcr ◽  
Complete Inactivation ◽  
The Status ◽  
Droplet Pcr

Background. CHEK2-associated neoplasms account for a significant proportion of hereditary breast cancer (BC) in Russia. The phenomenon of somatic deletion of the normal allele of a gene affected by a hereditary mutation, or loss of heterozygosity (LOH), is a frequent mechanism of complete inactivation of the corresponding protein, which is realized during the development of hereditary breast carcinomas. The contribution of the LOH phenomenon to the pathogenesis of CHEK2-dependent tumors is poorly understood, and almost all available data concern only one type of mutations - CHEK2 1100delC. The aim of the study was to characterize the frequency of LOH in breast tumor tissues from carriers of the three types of CHEK2 alterations: CHEK2 1000delC, CHEK2 IVS2+1G>A, and CHEK2 del5395. Materials and methods. LOH analysis was performed in a group of 50 breast cancer cases from women carrying CHEK2 1000delC (n = 19), CHEK2 IVS2+1G>A (n = 12), and CHEK2 del5395 (n = 19) mutations. Detection of LOH was carried out using a combination of methods that directly analyze the mutation locus (allele-specific PCR, Sanger sequencing, digital droplet PCR), and assess the status of single nucleotide polymorphisms surrounding the CHEK2 gene (digital droplet PCR).Results. The frequency of the LOH phenomenon in the studied cohort reached 27/50 (54%). Loss of heterozygosity was observed in 10/19 (52.6%) CHEK2 1000delC-associated, 6/12 (50%) CHEK2 IVS2+1G>A-associated, and 11/19 (57.9%) CHEK2 del5395-associated tumors. In one carcinoma from a carrier of the CHEK2 IVS2+1G>A alteration, the loss of mutated allele was confirmed. The main clinical and pathological characteristics were compared between tumors with loss and retention of heterozygosity. This comparison did not reveal any significant differences.Conclusion. Loss of heterozygosity is observed in about half of breast carcinomas arising in CHEK2 mutation carriers; the frequency of this phenomenon does not differ between three types of CHEK2 genetic defects.

scholarly journals Assessment of Erythroid Chimerism in Sickle Cell Patients Undergoing HSCT By Digital Droplet PCR

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 563-563
Author(s):  
Lihui Yin ◽  
Rupa A Udani ◽  
Mary Parlow ◽  
Daniel B Bellissimo ◽  
Joel A Brochstein
Keyword(s):  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Hematopoietic Stem ◽  
Post Transplant ◽  
Digital Droplet Pcr ◽  
Blood Disorder ◽  
The Status ◽  
Droplet Pcr ◽  
Allele Specific ◽  
Donor Genotype

Abstract Sickle cell disease (SCD) is an inherited autosomal recessive blood disorder associated with significant morbidity. Nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT) is increasingly used in severely affected patients with SCD. These transplants result in mixed hematopoietic chimerism so accurate chimerism testing is important for monitoring the status of the transplant. Reconstitution of the erythroid compartment is essential. Since red cells lack a nucleus, DNA-based chimerism assays do not directly assess the chimerism in the erythroid compartment. Several studies have shown that the chimerism in the white cells and erythroid cells can be very different (W, C., etal. Exp. Hematol. 2003, 31:924; Andreanni, M., etal. Haematologica, 2011, 96:128). We developed a procedure for quantification of chimerism in the erythroid compartment of blood using RNA-based digital droplet PCR (ddPCR). The sensitivity and specificity of the assay was evaluated then tested post-transplant samples from sickle cell patients. Total RNA is reverse transcribed and amplified in a two-step RT-PCR approach. The PCR reaction containing allele-specific hydrolysis probes is partitioned into ~15,000 droplets then amplified. The copy number of HbA and HbS transcripts from cells of the erythroid lineage is determined with ddPCR (BioRad, QX-200). The %HbA and the %Donor can be calculated using the donor genotype (A/A or A/S). The assay is designed to have a sensitivity of 1% with donor genotype of A/A and 5% with donor genotype of A/S. Each post-transplant sample is tested in duplicate along with an AA control, SS control, AS control and 1% sensitivity controls (5 controls total). Thirty AA or SS samples were tested to assess assay specificity. The average %HbA detected in a SS sample was 0.03%; the average %HbS in a AA sample was as 0.02%. The background signal is significantly below the cutoff for 1% sensitivity. Using contrived samples with low, medium, and high %HbA, we demonstrate the assay is accurate and linear to 0-2%HbA across the reportable range of 0%HbA to 100%HbA. The % CV of the minor allele for samples in the range of 10%-90%HbA, were equal or below 15%. A total of 11 post-transplant samples from 7 transplanted sickle cell patients were tested, and the results were compared to DNA-based/FISH chimerism, if available. Our results were comparable with DNA-based chimerism (Table 1). Five of the samples had slightly higher %donor in the erythroid compartment compared to the white cell compartment. The erythroid chimerism reflected changes in chimerism status: the decrease then increase in chimerism (P2), stable chimerism (P5) and graft failure (P7). Abstract 563. Table 1: Erythroid chimerism status of post-transplant SCD patients Patient # Donor Genotype Sample # %HbA %Donor %Recipient %Donor by FISH/STR P1 AS 1 52 100 0 95 P2 AA 1 66 66 34 72 2 44 44 56 50 3 100 100 0 95 P3 AS 1 54 100 0 85 P4 AA 1 100 100 0 100 P5 AS 1 14 28 72 15 2 12 24 76 15 P6 AS 1 57 100 0 95 P7 AA 1 0 0 100 Rejecting graft 2 0 0 100 Rejecting graft Assessment of the chimerism in the erythroid lineage may be a better indicator of donor erythropoiesis. We describe an accurate and sensitive assay for monitoring erythroid chimerism and the effects of post-transplant therapies in sickle cell patients undergoing HSCT. This assay also demonstrates the feasibility measuring erythroid chimerism detection in other hematologic disorders, such as thalassemia. Disclosures No relevant conflicts of interest to declare.

scholarly journals LRRC3B polymorphisms contributed to breast cancer susceptibility in Chinese Han Population

2020 ◽  
Author(s):  
Tianbo Jin ◽  
Linna Peng ◽  
Shishi Xing ◽  
Dandan Li ◽  
Chunjuan He ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Poor Prognosis ◽  
Cancer Susceptibility ◽  
Breast Cancer Susceptibility ◽  
Suppressor Gene ◽  
Nucleotide Polymorphisms ◽  
Chinese Han ◽  
Single Nucleotide ◽  
Increased Risk ◽  
The Status

Abstract Purpose LRRC3B gene, as a tumor suppressor gene was involved in the development and progress of breast cancer (BC). However, the effect of LRRC3B polymorphisms on BC has rarely been reported. In the study, we aims to evaluate the relation between LRRC3B variants and BC risk. Methods Among 563 BC patients and 552 healthy controls, ten single-nucleotide polymorphisms (SNPs) in LRRC3B were genotyped by Agena MassARRAY. Odds ratios (OR) and 95% confidence interval (CI) was calculate using logistic regression model. Results Our study demonstrated that rs1907168 polymorphism (OR = 0.71, p = 0.017) reduced the risk of BC in the overall. In stratified analyses by age, rs1907168 decreased (OR = 0.53, p = 0.002) while rs78205284 (OR = 2.83, p = 0.034) increased BC susceptibility among the population at age ≤ 51 years. Clinical parameters such as tumor size, the status of PR and Ki67 were associated with LRRC3B variants. Furthermore, we found that the association of ‘GATT’ haplotype with an increased risk for BC. In addition, LRRC3B gene was down-regulated in BC tumor and had a poor prognosis in BC in silico analysis. Conclusion Our study firstly found LRRC3B SNPs contributed to the risk of BC, suggesting LRRC3B variants might help to predict BC progression.

scholarly journals Association of single nucleotide polymorphisms rs63751445 of the MSH2 gene and rs863224614 of the MSH6 gene with susceptibility to breast cancer in samples from Northeast Brazil

2020 ◽  
Vol 9 (9) ◽  
pp. e368997007
Author(s):  
Agnaldo Luiz do Nascimento ◽  
Mayara dos Santos Maia ◽  
Poliane da Silva Calixto ◽  
Maria Isabela Ferreira de Araújo ◽  
Augusto Monteiro de Souza ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Single Nucleotide Polymorphisms ◽  
Histopathological Examination ◽  
Nucleotide Polymorphisms ◽  
Msh2 Gene ◽  
Chi Square ◽  
Single Nucleotide ◽  
Female Population ◽  
Specific Pcr ◽  
Msh6 Gene

Breast cancer (BC) is the cancer with the greatest epidemiological impact on the female population worldwide. The disease has a multifactorial etiology, with genetic implications that are not fully understood. In this context, genetic changes in the mismatch repair mechanism are notable for their potential relationship with BC, especially the single nucleotide polymorphisms (SNPs), which are the most common type of genetic variation. The aim of this study was to evaluate for the first time the influence of the SNPs rs63751445 (A>G) of the MSH2 gene and rs863224614 (T>G) of the MSH6 gene for susceptibility to CM. For that, 100 samples obtained by histopathological examination of patients from the Northeast region of Brazil were used. The methodology used was the Didesoxy Single Allele Specific PCR (DSASP) method. Statistical analysis was performed by comparison with the control population (population in Hardy-Weinberg equilibrium) using Pearson's Chi-square and Fischer's exact tests. It was concluded that these two SNPs may be associated with susceptibility to BC in the studied population.

scholarly journals 1198P Digital droplet PCR-based detection of TP53 mutations in circulating DNA for the disease monitoring in patients with hereditary ovarian or breast cancer

2020 ◽  
Vol 31 ◽  
pp. S787-S788
Author(s):  
E. Imyanitov ◽  
S. Aleksakhina ◽  
T. Gorodnova ◽  
E. Anisimova ◽  
L. Gigolayeva ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Disease Monitoring ◽  
Circulating Dna ◽  
Tp53 Mutations ◽  
Digital Droplet Pcr ◽  
Droplet Pcr

scholarly journals The frequency and spectrum of PIK3CA mutations in patients with estrogen receptor-positive HER2-negative advanced breast cancer residing in various regions of Russia

2021 ◽  
Vol 23 (1) ◽  
pp. 61-67
Author(s):  
Tatiana N. Sokolova ◽  
Svetlana N. Aleksakhina ◽  
Grigoriy A. Yanus ◽  
Aleksandr V. Sultanbaev ◽  
Konstantin V. Menshikov ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Molecular Genetic ◽  
Morphological Characteristics ◽  
Breast Cancer Patients ◽  
Pik3ca Mutations ◽  
Specific Pcr ◽  
Estrogen Receptor Positive ◽  
Er Positive ◽  
Droplet Pcr

Relevance. PIK3CA belongs to the top three most frequently mutated genes in breast cancer (BC), especially in estrogen receptor (ER) positive, HER2 negative BC subtype. With an approval of selective PI3K-alpha inhibitor, alpelisib, this alteration has become actionable in ER+HER2- tumors. The frequency and spectrum of PIK3CA alterations in various cohorts is affected by a number of factors, including the distribution of BC expression subtypes, histological types, patient age, and even ethnicity. Aim. Aim of the current study was to characterize the frequency and spectrum of PIK3CA alterations in Russian BC patients. Materials and methods. The analysis of PIK3CA exon 7, 9 and 20 mutations was performed in a cohort of Russian ER+HER2- BC patients by a combination of high-resolution melting analysis, allele-specific PCR, and digital droplet PCR. Results. PIK3CA lesions were identified in 62/206 (30%) patients. Noteworthy, 59/62 (95%) of the identified variants were represented by the three most common p.E542K, p.E545K, and p.H1047R substitutions. The analysis of clinical and morphological characteristics revealed the trends towards association of PIK3CA mutations with older age and more frequent metastatic lung involvement. Conclusion. The obtained data on the frequency and spectrum of PIK3CA somatic aberrations can be helpful when organizing molecular genetic testing of breast cancer patients and using PI3K inhibitors in Russian population.

scholarly journals Detection of TP53 mutations in plasma of ovarian cancer and breast cancer patients

2021 ◽  
Vol 67 (2) ◽  
pp. 260-267
Author(s):  
Aglaya Iyevleva ◽  
Tatiana Gorodnova ◽  
Svetlana Aleksakhina ◽  
Elena Anisimova ◽  
Larisa Gigolaeva ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Ovarian Cancer ◽  
Tp53 Gene ◽  
Circulating Tumor Dna ◽  
High Grade ◽  
Plasma Samples ◽  
Tp53 Mutations ◽  
Digital Droplet Pcr ◽  
Droplet Pcr ◽  
Tumor Dna

Background. The analysis of circulating tumor DNA provides wide opportunities for monitoring the results of cancer treatment. Somatic mutations in TP53 gene are present in almost all breast carcinomas developing in hereditary BRCA1 mutation carriers, as well as in the majority of high-grade serous ovarian tumors, which makes it possible to use them for effective monitoring of these diseases. The aim of the study was to analyze the content of tumor-specific TP53 mutations in plasma of patients with high-grade serous ovarian cancer (OC) and BRCA1-associated breast cancer (BC). Materials and methods. At least one plasma sample was obtained from 10 patients with OC and 7 patients with BRCA1-associated BC. The primary intratumoral status of TP53 gene was determined in the archival tumor material by targeted next generation sequencing. Digital droplet PCR was applied for testing of plasma samples for the presence of tumor-specific TP53 mutations, and in one case, BRAF V600E mutation. Results. All 8 plasma samples obtained from OC patients at the time of disease progression, before or during neoadjuvant chemotherapy, were positive for TP53 mutations. In contrast, 8 OC plasma samples obtained during remission, after surgery, or after neoadjuvant chemotherapy did not contain tumor-specific mutations. In breast cancer, circulating tumor DNA was detected in 2 of 4 samples obtained before treatment, and was not detected after the end of therapy or in remission. Conclusion. There is a good correlation between the presence of tumor-specific TP53 mutations in circulating DNA and the disease status in OC patients, therefore TP53 is a promising marker for clinical monitoring of ovarian cancer. In breast cancer, circulating tumor DNA is less abundant, therefore TP53 mutations cannot be reliably detected by digital droplet PCR in the plasma of patients with moderate disease burden.

scholarly journals Digital Droplet PCR for Rapid Quantification of Donor DNA in the Circulation of Transplant Recipients as a Potential Universal Biomarker of Graft Injury

2013 ◽  
Vol 59 (12) ◽  
pp. 1732-1741 ◽  
Author(s):  
Julia Beck ◽  
Sarah Bierau ◽  
Stefan Balzer ◽  
Reiner Andag ◽  
Philipp Kanzow ◽  
...  
Keyword(s):  
Maintenance Phase ◽  
Cost Effective ◽  
Therapeutic Interventions ◽  
Nucleotide Polymorphisms ◽  
Transplant Recipients ◽  
Single Nucleotide ◽  
Digital Droplet Pcr ◽  
Cost Effective Method ◽  
Potential Biomarker ◽  
Droplet Pcr

BACKGROUND Cell-free DNA (cfDNA) from grafts in the circulation of transplant recipients is a potential biomarker of rejection. Its usefulness was investigated after heart transplantation during the maintenance phase by use of microarrays and massive parallel sequencing of donor and recipient DNA. Disadvantages of these methods are high costs, long turnaround times, and need for donor DNA. Therefore, we sought to develop a rapid and cost-effective method using digital droplet PCR (ddPCR). METHODS Plasma samples were collected from stable recipients after liver (LTx, n = 10), kidney (KTx, n = 9), and heart (HTx, n = 8) transplantation as well as from 7 additional patients directly after LTx. Known single-nucleotide polymorphisms were selected for high minor allelic frequencies, of which 41 hydrolysis probe assays were established. Plasma cfDNA was preamplified, followed by conventional real-time PCR to define informative (heterologous) SNPs, which were then used for quantification (percentage) of graft-derived cfDNA (GcfDNA) using ddPCR. RESULTS Mean recovery was 94% (SD, 13%) with an imprecision of 4%–14% with the use of controls with 2% minor allele. GcfDNA in stable patients was <6.8% (LTx), <2.5% (KTx), and <3.4% (HTx). On the day of LTx, GcfDNA was approximately 90% and by day 10 it was <15% in complication-free LTx recipients. In 2 patients with biopsy-proven rejection, GcfDNA increased to >60%, whereas in 1 patient with cholestasis no increase was found. CONCLUSIONS A novel, cost-effective, rapid technique was developed to quantify GcfDNA in transplant recipients. This technique embodies a promising, potentially universal biomarker for early detection of rejection, which could enable more effective therapeutic interventions.

Statin-induced adverse effects – facts and genes

2013 ◽  
Vol 154 (3) ◽  
pp. 83-92
Author(s):  
Mariann Harangi ◽  
Noémi Zsíros ◽  
Lilla Juhász ◽  
György Paragh
Keyword(s):  
Risk Factors ◽  
Single Nucleotide Polymorphisms ◽  
Adverse Effects ◽  
Adverse Events ◽  
Statin Therapy ◽  
Significant Proportion ◽  
Gene Mutations ◽  
Nucleotide Polymorphisms ◽  
Serious Adverse Events ◽  
Single Nucleotide

Statin therapy is considered to be safe and rarely associated with serious adverse events. However, a significant proportion of patients on statin therapy show some degree of intolerance which can lead to decreased adherence to statin therapy. The authors summarize the symptoms, signs and frequencies of the most common statin-induced adverse effects and their most important risk factors including some single nucleotide polymorphisms and gene mutations. Also, they review the available approaches to detect and manage the statin-intolerant patients. Orv. Hetil., 2013, 154, 83–92.

Estrogen responsive finger protein as a new potential biomarker for breast cancer

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Breast Carcinoma ◽  
Cancer Patients ◽  
Mrna Level ◽  
Significant Prognostic Factor ◽  
Breast Carcinomas ◽  
Finger Protein ◽  
Potential Biomarker ◽  
Human Breast Carcinomas

Purpose: Estrogen-responsive finger protein (Efp) is amember ofRINGfinger-B box-Coiled Coilfamily and is also a downstream target of estrogen receptor a. Previously, Efp was shown tomediate estrogen-induced cell growth, which suggests possible involvement in the developmentof human breast carcinomas. In this study, we examined expression of Efp in breast carcinomatissues and correlated these findings with various clinicopathologic variables.Experimental Design: Thirty frozen specimens of breast carcinomas were used for immunohistochemistryand laser capture microdissection/real-time PCR of Efp. Immunohistochemistryfor Efp was also done in 151breast carcinoma specimens fixed with formalin and embedded inparaffinwax.Results: Efp immunoreactivity was detected in breast carcinoma cells and was significantlyassociated with the mRNA level (n = 30). Efp immunoreactivity was positively associated withlymph node status or estrogen receptor a status and negatively correlated with histologic gradeor 14-3-3j immunoreactivity (n = 151). Moreover, Efp immunoreactivity was significantly correlatedwith poor prognosis of breast cancer patients, and multivariate analyses of disease-freesurvival and overall survival for151breast cancer patients showed that Efp immunoreactivity wasthe independentmarker.Conclusions: Our data suggest that Efp immunoreactivity is a significant prognostic factor inbreast cancer patients. These findings may account for an oncogenic role of Efp in the tumorprogression of breast carcinoma.

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