Publications by authors named "Marianna Borecka"

10 Publications

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Novel presentation of the c.1856A > G (p.Asp619Gly) TSHR gene-activating variant: relapsing hyperthyroidism in three subsequent generations manifesting in early childhood and an in vitro functional study.

Hormones (Athens) 2021 Jun 18. Epub 2021 Jun 18.

Vera Vavrova Laboratory/VIAL, Department of Pediatrics, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic.

Background: Familial non-autoimmune hyperthyroidism is a rare disease caused by germline activating variants in the thyroid-stimulating hormone receptor (TSHR) gene. The c.1856A > G (p.Asp619Gly) pathogenic variant has been described in cases of toxic adenoma but never before, to our knowledge, in a case of familial non-autoimmune hyperthyroidism.

Patient Findings: A 3-year-old boy was admitted for acute gastroenteritis presenting with goiter and tall stature. Laboratory findings revealed peripheral hyperthyroidism and negativity for thyroid autoantibodies. Antithyroid drug treatment was effective, but relapses occurred shortly after attempts to decrease the drug dose. As the boy's father and paternal grandmother also experienced relapsing hyperthyroidism manifesting in early childhood, genetic testing of TSHR was indicated. The c.1856A > G (p.Asp619Gly) pathogenic variant was found in all three affected family members. Functional in vitro characterization of the variant verified that it enhances constitutional activation of the receptor, leading to increased production of cyclic adenosine monophosphate. Total thyroidectomy was indicated in the boy due to an unsatisfactory prognosis. Due to persistent positive thyroglobulin serum concentration, a diagnostic radioiodine scan was performed approximately 2 years later. Residual thyroid tissue was revealed; therefore, radioiodine ablative therapy was performed. Despite adequate thyroxine substitution over a long period of follow-up, TSH remained suppressed.

Conclusions: Unlike Graves' disease, familial non-autoimmune hyperthyroidism cases present with antithyroid drug-dependence. Not ultrasound but positive thyroglobulin serum concentration indicated residual thyroid tissue. Early detection of residual thyroid tissue and radioiodine ablation prevented the subject from experiencing relapsing hyperthyroidism and undergoing unnecessary repeated surgery. Life-long hormone substitution should be adjusted to free thyroxine rather than TSH serum concentrations.
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http://dx.doi.org/10.1007/s42000-021-00299-xDOI Listing
June 2021

Multigene Panel Germline Testing of 1333 Czech Patients with Ovarian Cancer.

Cancers (Basel) 2020 Apr 13;12(4). Epub 2020 Apr 13.

Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, 128 53 Prague, Czech Republic.

Ovarian cancer (OC) is the deadliest gynecologic malignancy with a substantial proportion of hereditary cases and a frequent association with breast cancer (BC). Genetic testing facilitates treatment and preventive strategies reducing OC mortality in mutation carriers. However, the prevalence of germline mutations varies among populations and many rarely mutated OC predisposition genes remain to be identified. We aimed to analyze 219 genes in 1333 Czech OC patients and 2278 population-matched controls using next-generation sequencing. We revealed germline mutations in 18 OC/BC predisposition genes in 32.0% of patients and in 2.5% of controls. Mutations in , , , and mismatch repair genes conferred high OC risk (OR > 5). Mutations in and were associated with moderate risk (both OR = 3.5). mutations dominated in almost all clinicopathological subgroups including sporadic borderline tumors of ovary (BTO). Analysis of remaining 201 genes revealed somatic mosaics in and germline mutations in and associating with a high/moderate OC risk significantly; however, further studies are warranted to delineate their contribution to OC development in other populations. Our findings demonstrate the high proportion of patients with hereditary OC in Slavic population justifying genetic testing in all patients with OC, including BTO.
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http://dx.doi.org/10.3390/cancers12040956DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7226062PMC
April 2020

Truncated PPM1D impairs stem cell response to genotoxic stress and promotes growth of APC-deficient tumors in the mouse colon.

Cell Death Dis 2019 10 28;10(11):818. Epub 2019 Oct 28.

Cancer Cell Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.

Protein phosphatase magnesium-dependent 1 delta (PPM1D) terminates cell response to genotoxic stress by negatively regulating the tumor suppressor p53 and other targets at chromatin. Mutations in the exon 6 of the PPM1D result in production of a highly stable, C-terminally truncated PPM1D. These gain-of-function PPM1D mutations are present in various human cancers but their role in tumorigenesis remains unresolved. Here we show that truncated PPM1D impairs activation of the cell cycle checkpoints in human non-transformed RPE cells and allows proliferation in the presence of DNA damage. Next, we developed a mouse model by introducing a truncating mutation in the PPM1D locus and tested contribution of the oncogenic PPM1D allele to colon tumorigenesis. We found that p53 pathway was suppressed in colon stem cells harboring PPM1D resulting in proliferation advantage under genotoxic stress condition. In addition, truncated PPM1D promoted tumor growth in the colon in Apc mice and diminished survival. Moreover, tumor organoids derived from colon of the ApcPpm1d mice were less sensitive to 5-fluorouracil when compared to ApcPpm1dand the sensitivity to 5-fluorouracil was restored by inhibition of PPM1D. Finally, we screened colorectal cancer patients and identified recurrent somatic PPM1D mutations in a fraction of colon adenocarcinomas that are p53 proficient and show defects in mismatch DNA repair. In summary, we provide the first in vivo evidence that truncated PPM1D can promote tumor growth and modulate sensitivity to chemotherapy.
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http://dx.doi.org/10.1038/s41419-019-2057-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6817818PMC
October 2019

Contribution of Massive Parallel Sequencing to Diagnosis of Hereditary Ovarian Cancer in the Czech Republic.

Klin Onkol 2019 ;32(Supplementum2):72-78

Background: Ovarian cancer is a disease with high mortality. Approximately 1,000 women are diagnosed with ovarian cancer in the Czech Republic annually. Women harboring a mutation in cancer-predisposing genes face an increased risk of tumor development. Mutations in BRCA1, BRCA2, BRIP1, and Lynch syndrome genes (RAD51C, RAD51D, and STK11) are associated with a high risk of ovarian cancer, and mutations in ATM, CHEK2, NBN, PALB2, and BARD1 appear to increase the risk. Our aim was to examine the frequency of mutations in cancer-predisposing genes in the Czech Republic.

Materials And Methods: We analyzed 1,057 individuals including ovarian cancer patients and 617 non-cancer controls using CZECANCA panel next-generation sequencing on the Illumina platform. Pathogenic mutations in high-risk genes, including CNVs, were detected in 30.6% of patients. The mutation frequency reached 25.0% and 18.2% in subgroups of unselected ovarian cancer patients and patients with a negative family cancer history, respectively. The most frequently mutated genes were BRCA1 and BRCA2. The overall frequency of mutations in non-BRCA genes was comparable to that in BRCA2. The mutation frequency in ovarian cancer patients aged >70 years was three times higher than that in patients diagnosed before the age of 30.

Conclusion: Ovarian cancer is a heterogeneous disease with a high proportion of hereditary cases. The lack of efficient screening for early diagnosis emphasizes the importance of identifying carriers of mutations in ovarian cancer-predisposing genes; this is because proper follow-up and prevention strategies can reduce overall ovarian cancer-related mortality. This work was supported by grants AZV 15-27695A, SVV2019/260367, PROGRES Q28/LF1. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 7. 3. 2019 Accepted: 24. 4. 2019.
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http://dx.doi.org/10.14735/amko2019S72DOI Listing
January 2020

Germline CHEK2 Gene Mutations in Hereditary Breast Cancer Predisposition - Mutation Types and their Biological and Clinical Relevance.

Klin Onkol 2019 ;32(Supplementum2):36-50

Background: Hereditary mutations in the CHEK2 gene (which encodes CHK2 kinase) contribute to a moderately increased risk of breast cancer (BC) and other cancers. Large variations in the frequency of CHEK2 mutations and the occurrence of variants of unknown clinical significance (VUS) complicate estimation of cancer risk in carriers of germline CHEK2 mutations.

Patients And Methods: We performed mutation analysis of 1,526 high-risk Czech BC patients and 3,360 Czech controls. Functional analysis was performed for identified VUS using a model system based on a human RPE1-CHEK2-KO cell line harboring biallelic inactivation of endogenous CHEK2.

Results: The frequency of ten truncating CHEK2 variants differed markedly between BC patients (2.26%) and controls (0.11%; p = 4.1 × 1012). We also found 23 different missense variants in 4.5% patients and in 4.0% of controls. The most common was p.I157T, which was found in patients and controls with the same frequency. Functional analysis identified nine functionally deleterious VUS, another nine functionally neutral VUS, and four intermediate VUS (including p.I157T). We found that carriers of truncating CHEK2 mutations had a high BC risk (OR 8.19; 95% CI 4.11-17.75), and that carriers of functionally deleterious missense variants had a moderate risk (OR 4.06; 95% CI, 1.37-13.39). Carriers of these mutations developed BC at 44.4 and 50.7 years, respectively. Functionally neutral and functionally intermediate missense variants did not increase the BC risk. BC in CHEK2 mutation carriers was frequently ER-positive and of higher grade. Notably, carriers of CHEK2 mutations developed second cancers more frequently than BRCA1/BRCA2/PALB2/p53 or mutation non-carriers.

Conclusion: Hereditary CHEK2 mutations contribute to the development of hereditary BC. The associated cancer risk in mutation carriers increases with the number of affected individuals in a family. Annual follow-up with breast ultrasound, mammography, or magnetic resonance imaging is recommended for asymptomatic mutation carriers from the age of 40. Surgical prevention and specific follow-up of other tumors should be considered based on family cancer history. The work was supported by grants from the Czech Health Research Council of the Ministry of Health of the Czech Republic NR 15-28830A, 16-29959A, NV19-03-00279, projects of the PROGRES Q28/LF1, GAUK 762216, SVV2019 / 260367, PRIMUS/17/MED/9, UNCE/MED/016, Progress Q26, LQ1604 NPU II and project AVČR Qualitas. The analysis of a set of unselected controls was made possible by the existence and support of the scientific infrastructure of the National Center for Medical Genomics (LM2015091) and its project aimed at creating a reference database of genetic variants of the Czech Republic (CZ.02.1.01/0.0/0.0/16_013/0001634). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 2. 4. 2019 Accepted: 14. 5. 2019.
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http://dx.doi.org/10.14735/amko2019S36DOI Listing
January 2020

Estrogen Receptor Status Oppositely Modifies Breast Cancer Prognosis in Mutation Carriers Versus Non-Carriers.

Cancers (Basel) 2019 May 28;11(6). Epub 2019 May 28.

Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, U Nemocnice 5, 128 00 Prague 2, Czech Republic.

Breast cancer (BC) prognosis in BRCA1 and BRCA2 mutation carriers has been reported contradictorily, and the significance of variables influencing prognosis in sporadic BC is not established in BC patients with hereditary BRCA1/BRCA2 mutations. In this retrospective cohort study, we analyzed the effect of clinicopathological characteristics on BC prognosis (disease-free survival [DFS] and disease-specific survival [DSS]) in hereditary BRCA1/BRCA2 mutation carriers. We enrolled 234 BRCA1/BRCA2 mutation carriers and 899 non-carriers, of whom 191 carriers and 680 non-carriers, with complete data, were available for survival analyses. We found that patients with ER-positive tumors developed disease recurrence 2.3-times more likely when they carried a BRCA1/BRCA2 mutation (23/60; 38.3% ER-positive carriers vs. 74/445; 16.6% ER-positive non-carriers; < 0.001). ER-positive mutation carriers also had a 3.4-times higher risk of death due to BC compared with ER-positive non-carriers (13/60; 21.7% vs. 28/445; 6.3%; < 0.001). Moreover, prognosis in ER-negative BRCA1/BRCA2 mutation carriers was comparable with that in ER-positive non-carriers. Our study demonstrates that ER-positivity worsens BC prognosis in BRCA1/BRCA2 mutation carriers, while prognosis for carriers with ER-negative tumors (including early-onset) is significantly better and comparable with that in ER-positive, older BC non-carriers. These observations indicate that BRCA1/BRCA2 mutation carriers with ER-positive BC represent high-risk patients.
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http://dx.doi.org/10.3390/cancers11060738DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6627684PMC
May 2019

Identification of deleterious germline CHEK2 mutations and their association with breast and ovarian cancer.

Int J Cancer 2019 10 20;145(7):1782-1797. Epub 2019 May 20.

Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic.

Germline mutations in checkpoint kinase 2 (CHEK2), a multiple cancer-predisposing gene, increase breast cancer (BC) risk; however, risk estimates differ substantially in published studies. We analyzed germline CHEK2 variants in 1,928 high-risk Czech breast/ovarian cancer (BC/OC) patients and 3,360 population-matched controls (PMCs). For a functional classification of VUS, we developed a complementation assay in human nontransformed RPE1-CHEK2-knockout cells quantifying CHK2-specific phosphorylation of endogenous protein KAP1. We identified 10 truncations in 46 (2.39%) patients and in 11 (0.33%) PMC (p = 1.1 × 10 ). Two types of large intragenic rearrangements (LGR) were found in 20/46 mutation carriers. Truncations significantly increased unilateral BC risk (OR = 7.94; 95%CI 3.90-17.47; p = 1.1 × 10 ) and were more frequent in patients with bilateral BC (4/149; 2.68%; p = 0.003), double primary BC/OC (3/79; 3.80%; p = 0.004), male BC (3/48; 6.25%; p = 8.6 × 10 ), but not with OC (3/354; 0.85%; p = 0.14). Additionally, we found 26 missense VUS in 88 (4.56%) patients and 131 (3.90%) PMC (p = 0.22). Using our functional assay, 11 variants identified in 15 (0.78%) patients and 6 (0.18%) PMC were scored deleterious (p = 0.002). Frequencies of functionally intermediate and neutral variants did not differ between patients and PMC. Functionally deleterious CHEK2 missense variants significantly increased BC risk (OR = 3.90; 95%CI 1.24-13.35; p = 0.009) and marginally OC risk (OR = 4.77; 95%CI 0.77-22.47; p = 0.047); however, carriers low frequency will require evaluation in larger studies. Our study highlights importance of LGR detection for CHEK2 analysis, careful consideration of ethnicity in both cases and controls for risk estimates, and demonstrates promising potential of newly developed human nontransformed cell line assay for functional CHEK2 VUS classification.
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http://dx.doi.org/10.1002/ijc.32385DOI Listing
October 2019

Genetic analysis of subsequent second primary malignant neoplasms in long-term pancreatic cancer survivors suggests new potential hereditary genetic alterations.

Cancer Manag Res 2019 10;11:599-609. Epub 2019 Jan 10.

Department of Oncology, Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic,

Background: The principal aim of this report was to study second primary malignant neoplasms (SMNs) in long-term survivors of pancreatic ductal adenocarcinoma (PDAC) with regard to the germline genetic background.

Patients And Methods: A total of 118 PDAC patients after a curative-intent surgery who were treated between 2006 and 2011 were analyzed. Of the 22 patients surviving for >5 years, six went on to develop SMNs. A genetic analysis of 219 hereditary cancer-predisposition and candidate genes was performed by targeted next-generation sequencing in germline DNA from 20 of these patients.

Results: Of all the radically resected PDAC patients, six patients went on to subsequently develop SMNs, which accounted for 27% of the long-term survivors. The median time to diagnosis of SMNs, which included two cases of rectal cancer, and one case each of prostate cancer, malignant melanoma, breast cancer, and urinary bladder cancer, was 52.5 months. At the time of analysis, none of these patients had died as a result of PDAC progression. We identified four carriers of germline pathogenic mutations in 20 analyzed long-term survivors. One carrier of the mutation was found among four analyzed patients who developed SMNs. Of the remaining 16 long-term PDAC survivors, 3 patients (19%) carried germline mutation(s) in the , , and gene, respectively.

Conclusion: This retrospective analysis indicates that SMNs in PDAC survivors are an important clinical problem and may be more common than has been acknowledged to be the case. In patients with good performance status, surgical therapy should be considered, as the SMNs often have a favorable prognosis.
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http://dx.doi.org/10.2147/CMAR.S185352DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6331079PMC
January 2019

Validation of CZECANCA (CZEch CAncer paNel for Clinical Application) for targeted NGS-based analysis of hereditary cancer syndromes.

PLoS One 2018 12;13(4):e0195761. Epub 2018 Apr 12.

Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic.

Background: Carriers of mutations in hereditary cancer predisposition genes represent a small but clinically important subgroup of oncology patients. The identification of causal germline mutations determines follow-up management, treatment options and genetic counselling in patients' families. Targeted next-generation sequencing-based analyses using cancer-specific panels in high-risk individuals have been rapidly adopted by diagnostic laboratories. While the use of diagnosis-specific panels is straightforward in typical cases, individuals with unusual phenotypes from families with overlapping criteria require multiple panel testing. Moreover, narrow gene panels are limited by our currently incomplete knowledge about possible genetic dispositions.

Methods: We have designed a multi-gene panel called CZECANCA (CZEch CAncer paNel for Clinical Application) for a sequencing analysis of 219 cancer-susceptibility and candidate predisposition genes associated with frequent hereditary cancers.

Results: The bioanalytical and bioinformatics pipeline was validated on a set of internal and commercially available DNA controls showing high coverage uniformity, sensitivity, specificity and accuracy. The panel demonstrates a reliable detection of both single nucleotide and copy number variants. Inter-laboratory, intra- and inter-run replicates confirmed the robustness of our approach.

Conclusion: The objective of CZECANCA is a nationwide consolidation of cancer-predisposition genetic testing across various clinical indications with savings in costs, human labor and turnaround time. Moreover, the unified diagnostics will enable the integration and analysis of genotypes with associated phenotypes in a national database improving the clinical interpretation of variants.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0195761PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5896995PMC
July 2018

The c.657del5 variant in the NBN gene predisposes to pancreatic cancer.

Gene 2016 Aug 2;587(2):169-72. Epub 2016 May 2.

Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic. Electronic address:

Pancreatic ductal adenocarcinoma (PDAC) is the sixth most frequent cancer type in the Czech Republic with a poor prognosis that could be improved by an early detection and subsequent surgical treatment combined with chemotherapy. Genetic factors play an important role in PDAC risk. We previously identified one PDAC patient harboring the Slavic founder deleterious mutation c.657del5 in the NBN gene, using a panel next-generation sequencing (NGS). A subsequent analysis of 241 unselected PDAC patients revealed other mutation carriers. The overall frequency of c.657del5 in unselected PDAC patients (5/241; 2.07%) significantly differed from that in non-cancer controls (2/915; 0.2%; P=0.006). The result indicates that the NBN c.657del5 variant represents a novel PDAC-susceptibility allele increasing PDAC risk (OR=9.7; 95% CI: 1.9 to 50.2). The increased risk of PDAC in follow-up recommendations for NBN mutation carriers should be considered if other studies also confirm an increased frequency of c.657del5 carriers in PDAC patients from other populations.
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http://dx.doi.org/10.1016/j.gene.2016.04.056DOI Listing
August 2016
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