309 research outputs found

    Mutational spectrum of APC and genotype-phenotype correlations in Greek FAP patients

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    <p>Abstract</p> <p>Background</p> <p>Familial adenomatous polyposis, an autosomal dominant inherited disease caused by germline mutations within the <it>APC </it>gene, is characterized by early onset colorectal cancer as a consequence of the intrinsic phenotypic feature of multiple colorectal adenomatic polyps. The genetic investigation of Greek adenomatous polyposis families was performed in respects to <it>APC </it>and <it>MUTYH </it>germline mutations. Additionally, all available published mutations were considered in order to define the <it>APC </it>mutation spectrum in Greece.</p> <p>Methods</p> <p>A cohort of 25 unrelated adenomatous polyposis families of Greek origin has been selected. Genetic testing included direct sequencing of <it>APC </it>and <it>MUTYH </it>genes. <it>APC </it>gene was also checked for large genomic rearrangements by MLPA.</p> <p>Results</p> <p>Analysis of the <it>APC </it>gene performed in a Greek cohort of twenty five FAP families revealed eighteen different germline mutations in twenty families (80%), four of which novel. Mutations were scattered between exon 3 and codon 1503 of exon 15, while no large genomic rearrangements were identified.</p> <p>Conclusion</p> <p>This concise report describes the spectrum of all <it>APC </it>mutations identified in Greek FAP families, including four novel mutations. It is concluded that the Greek population is characterized by genetic heterogeneity, low incidence of genomic rearrangements in <it>APC </it>gene and lack of founder mutation in FAP syndrome.</p

    Wastewater valorization by pure bacterial cultures to Extracellular Polymeric Substances (EPS) with high emulsifying potential and flocculation activities

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    Nowadays much effort has been devoted for the development of cost-effective and environmentally friendly processes to obtain extracellular polymeric substances (EPS) with high emulsifying and flocculation activities. The aim of this study was to evaluate the capacity of bacterial strains previously isolated from oil-contaminated areas to produce EPS with high emulsification and bioflocculant properties during cultivation in domestic and bilge wastewater and in industrial crude glycerol. A total of seven bacterial strains were screened for EPS production, from which two strains, Pseudomonas aeruginosa LVD-10 and Enterobacter sp. SW, were selected as potential EPS producers. EPS with high emulsifying capacity in olive oil (a maximum of 96.6 and 89.8% for strain SW and LVD-10, respectively) was produced using bilge wastewater as substrate. EPS with a slightly lower emulsifying capacity was obtained using crude glycerol. In addition, the flocculation activity of the EPS extracted from strains LVD-10 and SW grown on crude glycerol was considerably higher (81.6 and 73.3%, respectively) than that obtained with other substrates. This is the first study that points out that EPS with emulsifying and flocculation potential activity can be produced from bilge wastewater and crude glycerol. The production of biopolymers with broad biotechnological applications using low-cost substrates can be a means to valorise waste streams.info:eu-repo/semantics/publishedVersio

    Neoadjuvant treatment in ovarian cancer: New perspectives, new challenges

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    Ovarian cancer remains the leading cause of death from gynecological cancer. Survival is significantly related to the stage of the disease at diagnosis. Of quite importance is primary cytoreductive surgery, having as a goal to remove all visible tumor tissue, and is the standard primary treatment in combination with platinum-based chemotherapy for patients with advanced ovarian carcinoma.Neo-adjuvant chemotherapy (NACT) has been implemented mostly in treating advanced disease, with studies performed having numerous limitations. Data extrapolated from these studies have not shown inferiority survival of NACT, compared to primary debulking surgery. The role of NACT is of particular interest because of the intrinsic mechanisms that are involved in the process, which can be proven as therapeutic approaches with enormous potential. NACT increases immune infiltration and programmed death ligand-1 (PDL-1) expression, induces local immune activation, and can potentiate the immunogenicity of immune-exclude high grade serous ovarian tumors, while the combination of NACT with bevacizumab, PARP inhibitors or immunotherapy remains to be evaluated. This article summarizes all available data on studies implementing NACT in the treatment of ovarian cancer, focusing on clinical outcomes and study limitations. High mortality rates observed among ovarian cancer patients necessitates the identification of more effective treatments, along with biomarkers that will aid treatment individualization

    Screening of the DNA mismatch repair genes MLH1, MSH2 and MSH6 in a Greek cohort of Lynch syndrome suspected families

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    <p>Abstract</p> <p>Background</p> <p>Germline mutations in the DNA mismatch repair genes predispose to Lynch syndrome, thus conferring a high relative risk of colorectal and endometrial cancer. The <it>MLH1, MSH2 </it>and <it>MSH6 </it>mutational spectrum reported so far involves minor alterations scattered throughout their coding regions as well as large genomic rearrangements. Therefore, a combination of complete sequencing and a specialized technique for the detection of genomic rearrangements should be conducted during a proper DNA-testing procedure. Our main goal was to successfully identify Lynch syndrome families and determine the spectrum of <it>MLH1</it>, <it>MSH2 </it>and <it>MSH6 </it>mutations in Greek Lynch families in order to develop an efficient screening protocol for the Greek colorectal cancer patients' cohort.</p> <p>Methods</p> <p>Forty-two samples from twenty-four families, out of which twenty two of Greek, one of Cypriot and one of Serbian origin, were screened for the presence of germline mutations in the major mismatch repair genes through direct sequencing and MLPA. Families were selected upon Amsterdam criteria or revised Bethesda guidelines.</p> <p>Results</p> <p>Ten deleterious alterations were detected in twelve out of the twenty-four families subjected to genetic testing, thus our detection rate is 50%. Four of the pathogenic point mutations, namely two nonsense, one missense and one splice site change, are novel, whereas the detected genomic deletion encompassing exon 6 of the <it>MLH1 </it>gene has been described repeatedly in the LOVD database. The average age of onset for the development of both colorectal and endometrial cancer among mutation positive families is 43.2 years.</p> <p>Conclusion</p> <p>The mutational spectrum of the MMR genes investigated as it has been shaped by our analysis is quite heterogeneous without any strong indication for the presence of a founder effect.</p

    Evaluation of polygenic risk scores for breast and ovarian cancer risk prediction in BRCA1 and BRCA2 mutation carriers

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    Background: Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates. Methods: We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]-positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS. Results: The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P = 8.2 x 10(53)). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P = 7.2 x 10(-20)). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS. Conclusions: BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management

    BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers

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    Background: The K3326X variant in BRCA2 (BRCA2*c.9976A&gt;T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers. Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided. Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed. Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations

    Triple-Negative Breast Cancer Risk Genes Identified by Multigene Hereditary Cancer Panel Testing

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    Background: Germline genetic testing with hereditary cancer gene panels can identify women at increased risk of breast cancer. However, those at increased risk of triple-negative (estrogen receptor-negative, progesterone receptor-negative, human epidermal growth factor receptor-negative) breast cancer (TNBC) cannot be identified because predisposition genes for TNBC, other than BRCA1, have not been established. The aim of this study was to define the cancer panel genes associated with increased risk of TNBC. Methods: Multigene panel testing for 21 genes in 8753 TNBC patients was performed by a clinical testing laboratory, and testing for 17 genes in 2148 patients was conducted by a Triple Negative Breast Cancer Consortium(TNBCC) of research studies. Associations between deleterious mutations in cancer predisposition genes and TNBC were evaluated using results from TNBC patients and reference controls. Results: Germline pathogenic variants in BARD1, BRCA1, BRCA2, PALB2, and RAD51D were associated with high risk (odds ratio > 5.0) of TNBC and greater than 20% lifetime risk for overall breast cancer among Caucasians. Pathogenic variants in BRIP1, RAD51C, and TP53 were associated with moderate risk (odds ratio > 2) of TNBC. Similar trends were observed for the African American population. Pathogenic variants in these TNBC genes were detected in 12.0% (3.7% non-BRCA1/2) of all participants. Conclusions: Multigene hereditary cancer panel testing can identify women with elevated risk of TNBC due to mutations in BARD1, BRCA1, BRCA2, PALB2, and RAD51D. These women can potentially benefit from improved screening, risk management, and cancer prevention strategies. Patients with mutations may also benefit from specific targeted therapeutic strategies.Peer reviewe

    Triple negative breast cancer: proposals for a pragmatic definition and implications for patient management and trial design.

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    In trials in triple negative breast cancer (TNBC), oestrogen and progesterone receptor negativity should be defined as < 1% positive cells. Negativity is a ratio of <2 between Her2 gene copy number and centromere of chromosome 17 or a copy number of 4 or less. In routine practice, immunohistochemistry is acceptable given stringent quality assurance. Triple negativity emerging after neoadjuvant treatment differs from primary TN and such patients should not enter TNBC trials. Patients relapsing with TN metastases should be eligible even if their primary was positive. Rare TN subtypes such as apocrine, adenoid-cystic and low-grade metaplastic tumours should be excluded. TN and basal-like (BL) signatures overlap but are not equivalent. Since the significance of basal cytokeratin or EGFR overexpression is not known and we lack validated assays, these features should not be used to subclassify TN tumours. Tissue collection in trials is mandatory so the effect on outcome of different tumour phenotypes and BRCA mutation can be explored. No prospective studies have established that TN tumours have particular sensitivity or resistance to any specific chemotherapy agent or radiation. TNBC patients should be treated according to tumour and clinical characteristics
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