32 results on '"Falagan-Lotsch P"'
Search Results
2. Impact of Zero-Valent Iron on Freshwater Bacterioplankton Metabolism as Predicted from 16S rRNA Gene Sequence Libraries
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Nguyen, Nhung H. A., Špánek, Roman, Falagan-Lotsch, Priscila, and Ševců, Alena
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- 2021
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3. Challenges on the toxicological predictions of engineered nanoparticles
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Ribeiro, A.R., Leite, P.E., Falagan-Lotsch, P., Benetti, F., Micheletti, C., Budtz, H.C., Jacobsen, N.R., Lisboa-Filho, P.N., Rocha, L.A., Kühnel, D., Hristozov, D., and Granjeiro, J.M.
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- 2017
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4. Are your results valid? Cellular authentication a need from the past, an emergency on the present
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Cosme, Bruno, Falagan-Lotsch, Priscila, Ribeiro, Mariana, Napoleão, Kely, Granjeiro, José Mauro, and Moura-Neto, Rodrigo
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- 2017
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5. The functional EGF+61 polymorphism and nonsyndromic oral clefts susceptibility in a Brazilian population
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Priscila FALAGAN-LOTSCH, Talíria Silva LOPES, Erika Calvano KÜCHLER, Patrícia Nivoloni TANNURE, Marcelo de Castro COSTA, Lidia Maria da Fonte de AMORIM, and José Mauro GRANJEIRO
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Nonsyndromic oral clefts ,Cleft subphenotypes ,EGF ,Polymorphism ,Dentistry ,RK1-715 - Abstract
AbstractNonsyndromic oral clefts are considered a problem of public health in Brazil, presenting a multifactorial etiology that involves genetic and environmental components, such as maternal alcohol consumption. Several candidate genes have been investigated to identify some association with nonsyndromic clefts risk. The epidermal growth factor (EGF) gene is implicated in the normal craniofacial development and its functional +61 A>G polymorphism has been related to cancer susceptibility. It has been suggested that cancer and oral clefts may share the same molecular pathways.Objective Our goal was to evaluate the association between the EGF+61 A>G polymorphism and nonsyndromic oral clefts susceptibility.Material and Methods The case-control study included 218 cleft cases and 253 controls from Brazil. The control group was comprised of individuals without congenital malformations, dental anomalies and family history of clefts. The cleft phenotypes and subphenotypes were determined based on clinical examination. Genomic DNA was extracted from oral mucosa cells obtained by mouthwash. The EGF+61 A>G polymorphism genotype was determined by polymerase chain reaction-restriction fragment length polymorphism.Results We noticed the association between maternal alcohol consumption during pregnancy and cleft occurrence. The A allele and AA genotype were over-represented in cleft cases compared with control group when we considered the bilateral cleft lip with or without cleft palate (CL±P) cases, cleft cases with tooth agenesis and cleft cases presenting family history of cleft, but the differences were not statistically significant. Contradictorily, the G allele was higher in cleft palate only (CP) cases than in control group, showing a borderline p value. Comparing the different cleft phenotypes, we observed statistical differences between CP and CL±P cases. Our data suggest the EGF+61 A>G polymorphism was not related with nonsyndromic oral clefts susceptibility in a Brazilian population, but supported the different genetic background between CL±P and CP. Moreover, we confirmed the potential effect of maternal alcohol intake on cleft risk in our population.
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- 2015
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6. Successful Low-Cost Scaffold-Free Cartilage Tissue Engineering Using Human Cartilage Progenitor Cell Spheroids Formed by Micromolded Nonadhesive Hydrogel
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Mellannie P. Stuart, Renata A. M. Matsui, Matheus F. S. Santos, Isis Côrtes, Mayra S. Azevedo, Karina R. Silva, Anderson Beatrici, Paulo Emílio C. Leite, Priscila Falagan-Lotsch, José M. Granjeiro, Vladimir Mironov, and Leandra S. Baptista
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Internal medicine ,RC31-1245 - Abstract
The scaffold-free tissue engineering using spheroids is pointed out as an approach for optimizing the delivery system of cartilage construct. In this study, we aimed to evaluate the micromolded nonadhesive hydrogel (MicroTissues®) for spheroid compaction (2-day culture) and spontaneous chondrogenesis (21-day culture) using cartilage progenitors cells (CPCs) from human nasal septum without chondrogenic stimulus. CPC spheroids showed diameter stability (486 μm ± 65), high percentage of viable cells (88.1 ± 2.1), and low percentage of apoptotic cells (2.3%). After spheroid compaction, the synthesis of TGF-β1, TGF-β2, and TGF-β3 was significantly higher compared to monolayer (p
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- 2017
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7. Buccal cells DNA extraction to obtain high quality human genomic DNA suitable for polymorphism genotyping by PCR-RFLP and Real-Time PCR
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Erika Calvano Küchler, Patricia Nivoloni Tannure, Priscila Falagan-Lotsch, Taliria Silva Lopes, Jose Mauro Granjeiro, and Lidia Maria Fonte Amorim
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DNA ,Saliva ,PCR ,Genetic polymorphism ,Dentistry ,RK1-715 - Abstract
OBJECTIVE: The aim of this study was to evaluate, by PCR-RFLP and real-time PCR, the yield and quality of genomic DNA collected from buccal cells by mouthwash after different storage times at room temperature. MATERIAL AND METHODS: A group of volunteers was recruited to collect buccal cells using a mouthwash solution. The collected solution was divided into 3 tubes, one tube were used for immediate extraction and the remaining received ethanol and were kept at room temperature for 4 and 8 days followed by dna extraction. The concentration, purity and integrity of the dna were determined using spectrophotometry and electrophoresis. DNA quality differences among the three incubation times were also evaluated for genotyping EGF +61 a/g (rs 4444903) polymorphism by PCR-RFLP and for IRF6 polymorphism (rs 17015215) using real-time PCR. RESULTS: There was no significant difference of dna yield (p=0.75) and purity (p=0.86) among the three different incubation times. DNA obtained from different incubation times presented high-molecular weight. The PCR-RFLP and real time pcr reactions were successfully performed for all DNA samples, even those extracted after 8 days of incubation. All samples genotyped by real-time pcr presented c allele for irf6 gene polymorphism (homozygous: cc; heterozygous: Ct) and the C allele was used as a reference for Ct values. The samples presented the same genotype for the different times in both techniques. CONCLUSION: We demonstrated that the method described herein is simple and low cost, and that DNA can be extracted and pcr amplified after storage in mouthwash solution at room temperature.
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- 2012
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8. XRCC1 gene polymorphisms in a population sample and in women with a family history of breast cancer from Rio de Janeiro (Brazil)
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Priscila Falagan-Lotsch, Marina S. Rodrigues, Viviane Esteves, Roberto Vieira, Luis C. Amendola, Dante Pagnoncelli, Júlio C. Paixão, and Claudia V. De Moura Gallo
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XRCC1 gene polymorphisms ,breast cancer susceptibility ,Brazilian population ,Genetics ,QH426-470 - Abstract
The X-ray repair cross-complementing Group1 (XRCC1) gene has been defined as essential in the base excision repair (BER) and single-strand break repair processes. This gene is highly polymorphic, and the most extensively studied genetic changes are in exon 6 (Arg194Trp) and in exon 10 (Arg399Gln). These changes, in conserved protein sites, may alter the base excision repair capacity, increasing the susceptibility to adverse health conditions, including cancer. In the present study, we estimated the frequencies of the XRCC1 gene polymorphisms Arg194Trp and Arg399Gln in healthy individuals and also in women at risk of breast cancer due to family history from Rio de Janeiro. The common genotypes in both positions (194 and 399) were the most frequent in this Brazilian sample. Although the 194Trp variant was overrepresented in women reporting familial cases of breast cancer, no statistically significant differences concerning genotype distribution or intragenic interactions were found between this group and the controls. Thus, in the population analyzed by us, variants Arg194Trp and Arg399Gln did not appear to have any impact on breast cancer susceptibility.
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- 2009
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9. TP53 PIN3 and MDM2 SNP309 polymorphisms as genetic modifiers in the Li–Fraumeni syndrome: impact on age at first diagnosis
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Marcel, V, Palmero, E I, Falagan-Lotsch, P, Martel-Planche, G, Ashton-Prolla, P, Olivier, M, Brentani, R R, Hainaut, P, and Achatz, M I
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- 2009
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10. Nanoparticles Interfere with Chemotaxis: An Example of Nanoparticles as Molecular "Knockouts" at the Cellular Level.
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Zhang, Xi, Falagan-Lotsch, Priscila, and Murphy, Catherine J.
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- 2021
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11. Virus-Sized Gold Nanorods: Plasmonic Particles for Biology.
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Murphy, Catherine J., Chang, Huei-Huei, Falagan-Lotsch, Priscila, Gole, Matthew T., Hofmann, Daniel M., Hoang, Khoi Nguyen L., McClain, Sophia M., Meyer, Sean M., Turner, Jacob G., Unnikrishnan, Mahima, Wu, Meng, Zhang, Xi, and Zhang, Yishu
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- 2019
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12. Micro-arc oxidation as a tool to develop multifunctional calcium-rich surfaces for dental implant applications
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Ribeiro, A.R., primary, Oliveira, F., additional, Boldrini, L.C., additional, Leite, P.E., additional, Falagan-Lotsch, P., additional, Linhares, A.B.R., additional, Zambuzzi, W.F., additional, Fragneaud, B., additional, Campos, A.P.C., additional, Gouvêa, C.P., additional, Archanjo, B.S., additional, Achete, C.A., additional, Marcantonio, E., additional, Rocha, L.A., additional, and Granjeiro, J.M., additional
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- 2015
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13. Global transcriptomic analysis of model human cell lines exposed to surface-modified gold nanoparticles: the effect of surface chemistry
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Grzincic, E. M., primary, Yang, J. A., additional, Drnevich, J., additional, Falagan-Lotsch, P., additional, and Murphy, C. J., additional
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- 2015
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14. New Advances in Nanotechnology-Based Diagnosis and Therapeutics for Breast Cancer: An Assessment of Active-Targeting Inorganic Nanoplatforms.
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Falagan-Lotsch, Priscila, Grzincic, Elissa M., and Murphy, Catherine J.
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- 2017
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15. Association between the epidermal growth factor gene polymorphism and endometriosis in women from Brazil
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Oliveira, C.B.N., primary, Falagan-Lotsch, P., additional, Souza, M.G., additional, Santos, R.P., additional, Encinas, F., additional, Teles, H., additional, Lasmar, R.B., additional, Duarte, L.B., additional, Granjeiro, J.M., additional, and Penna, I.A., additional
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- 2014
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16. Prognostic and predictive value of TP53 mutations in node-positive breast cancer patients treated with anthracycline- or anthracycline/taxane-based adjuvant therapy: results from the BIG 02-98 phase III trial
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Fernandez-Cuesta, L, Oakman, C, Falagan-Lotsch, P, Smoth, K-S, Quinaux, E, Buyse, M, Dolci, MS, De Azambuja, E, Hainaut, P, Dell'Orto, P, Larsimont, D, Francis, PA, Crown, J, Piccart-Gebhart, M, Viale, G, Di Leo, A, Olivier, M, Fernandez-Cuesta, L, Oakman, C, Falagan-Lotsch, P, Smoth, K-S, Quinaux, E, Buyse, M, Dolci, MS, De Azambuja, E, Hainaut, P, Dell'Orto, P, Larsimont, D, Francis, PA, Crown, J, Piccart-Gebhart, M, Viale, G, Di Leo, A, and Olivier, M
- Abstract
INTRODUCTION: Pre-clinical data suggest p53-dependent anthracycline-induced apoptosis and p53-independent taxane activity. However, dedicated clinical research has not defined a predictive role for TP53 gene mutations. The aim of the current study was to retrospectively explore the prognosis and predictive values of TP53 somatic mutations in the BIG 02-98 randomized phase III trial in which women with node-positive breast cancer were treated with adjuvant doxorubicin-based chemotherapy with or without docetaxel. METHODS: The prognostic and predictive values of TP53 were analyzed in tumor samples by gene sequencing within exons 5 to 8. Patients were classified according to p53 protein status predicted from TP53 gene sequence, as wild-type (no TP53 variation or TP53 variations which are predicted not to modify p53 protein sequence) or mutant (p53 nonsynonymous mutations). Mutations were subcategorized according to missense or truncating mutations. Survival analyses were performed using the Kaplan-Meier method and log-rank test. Cox-regression analysis was used to identify independent predictors of outcome. RESULTS: TP53 gene status was determined for 18% (520 of 2887) of the women enrolled in BIG 02-98. TP53 gene variations were found in 17% (90 of 520). Nonsynonymous p53 mutations, found in 16.3% (85 of 520), were associated with older age, ductal morphology, higher grade and hormone-receptor negativity. Of the nonsynonymous mutations, 12.3% (64 of 520) were missense and 3.6% were truncating (19 of 520). Only truncating mutations showed significant independent prognostic value, with an increased recurrence risk compared to patients with non-modified p53 protein (hazard ratio = 3.21, 95% confidence interval = 1.740 to 5.935, P = 0.0002). p53 status had no significant predictive value for response to docetaxel. CONCLUSIONS: p53 truncating mutations were uncommon but associated with poor prognosis. No significant predictive role for p53 status was detected. TRIAL REGIST
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- 2012
17. MMP13 polymorphism decreases risk for dental caries
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Tannure, PN, Küchler, EC, Falagan-Lotsch, P, Amorim, LMF, Raggio Luiz, R, Costa, MC, Vieira, AR, Granjeiro, JM, Tannure, PN, Küchler, EC, Falagan-Lotsch, P, Amorim, LMF, Raggio Luiz, R, Costa, MC, Vieira, AR, and Granjeiro, JM
- Abstract
Recent evidence suggests that genetic studies may contribute to a better understanding of individual susceptibility to caries. Matrix metalloproteinases (MMPs) and their tissue inhibitors have been suggested to be involved in the caries process. The purpose of this study was to determine if polymorphisms in MMP2 (rs243865), MMP9 (rs17576), MMP13 (rs2252070), and TIMP2 (rs7501477) were associated with caries. Eligible unrelated children and adolescents were evaluated using a cross-sectional design. Data on oral health habits was obtained through a questionnaire and caries data was collected by clinical examination. Genotyping of the selected polymorphisms was carried out by real-time PCR. Allele and genotype frequencies were compared between individuals with and without caries experience. Of 505 subjects, 212 were caries-free and most subjects (61.2%) had mixed dentition. Allele frequency of MMP2, MMP13 and TIMP2 was different between caries-affected and caries-free individuals, with significant association for MMP13 (p = 0.004). Mutant allele carriers for MMP13 demonstrated a significantly decreased risk for caries (OR = 0.538, 95% CI 0.313-0.926); this result remained significant after adjustment for candidate genes, type of dentition and dietary factors. Allelic and genotype frequencies of the polymorphism in MMP9 were similar in caries-affected and caries-free individuals. Genetic variations in MMP13 may contribute to individual differences in caries susceptibility. Our findings reinforce that susceptibility to caries results from gene-environment interactions. Copyright © 2012 S. Karger AG, Basel.
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- 2012
18. MMP13 Polymorphism Decreases Risk for Dental Caries
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Tannure, P.N., primary, Küchler, E.C., additional, Falagan-Lotsch, P., additional, Amorim, L.M.F., additional, Raggio Luiz, R., additional, Costa, M.C., additional, Vieira, A.R., additional, and Granjeiro, J.M., additional
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- 2012
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19. An international comparability study on quantification of mRNA gene expression ratios: CCQM-P103.1
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Devonshire, Alison S., Sanders, Rebecca, Whale, Alexandra S., Nixon, Gavin J., Cowen, Simon, Ellison, Stephen L.R., Parkes, Helen, Pine, P. Scott, Salit, Marc, McDaniel, Jennifer, Munro, Sarah, Lund, Steve, Matsukura, Satoko, Sekiguchi, Yuji, Kawaharasaki, Mamoru, Granjeiro, José Mauro, Falagan-Lotsch, Priscila, Saraiva, Antonio Marcos, Couto, Paulo, Yang, Inchul, Kwon, Hyerim, Park, Sang-Ryoul, Demšar, Tina, Žel, Jana, Blejec, Andrej, Milavec, Mojca, Dong, Lianhua, Zhang, Ling, Sui, Zhiwei, Wang, Jing, Viroonudomphol, Duangkamol, Prawettongsopon, Chaiwat, Partis, Lina, Baoutina, Anna, Emslie, Kerry, Takatsu, Akiko, Akyurek, Sema, Akgoz, Muslum, Vonsky, Maxim, Konopelko, L.A., Cundapi, Edna Matus, Urquiza, Melina Pérez, Huggett, Jim F., and Foy, Carole A.
- Abstract
Measurement of RNA can be used to study and monitor a range of infectious and non-communicable diseases, with profiling of multiple gene expression mRNA transcripts being increasingly applied to cancer stratification and prognosis. An international comparison study (Consultative Committee for Amount of Substance (CCQM)-P103.1) was performed in order to evaluate the comparability of measurements of RNA copy number ratio for multiple gene targets between two samples. Six exogenous synthetic targets comprising of External RNA Control Consortium (ERCC) standards were measured alongside transcripts for three endogenous gene targets present in the background of human cell line RNA. The study was carried out under the auspices of the Nucleic Acids (formerly Bioanalysis) Working Group of the CCQM. It was coordinated by LGC (United Kingdom) with the support of National Institute of Standards and Technology (USA) and results were submitted from thirteen National Metrology Institutes and Designated Institutes. The majority of laboratories performed RNA measurements using RT-qPCR, with datasets also being submitted by two laboratories based on reverse transcription digital polymerase chain reaction and one laboratory using a next-generation sequencing method. In RT-qPCR analysis, the RNA copy number ratios between the two samples were quantified using either a standard curve or a relative quantification approach. In general, good agreement was observed between the reported results of ERCC RNA copy number ratio measurements. Measurements of the RNA copy number ratios for endogenous genes between the two samples were also consistent between the majority of laboratories. Some differences in the reported values and confidence intervals (‘measurement uncertainties’) were noted which may be attributable to choice of measurement method or quantification approach. This highlights the need for standardised practices for the calculation of fold change ratios and uncertainties in the area of gene expression profiling.
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- 2016
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20. Ser312Gly Polymorphism of the HSD17β1Gene is not Associated with Endometriosis in Brazilian Patients
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dos Santos, Raphaela P., Oliveira, Carolina B.N., Falagan-Lotsch, Priscila, Souza, Marcelle G., Lasmar, Ricardo B., Duarte, Luciana B., Navarro, Paula A., Granjeiro, José M., and Penna, Ivan A.
- Abstract
Purpose The aim of this study was to determine whether a polymorphism of the HSD17β1 gene (rs605059), involved in estrogen synthesis, is associated with endometriosis in Brazilian patients.Methods A case-control study was conducted in 231 women. All patients in the case group had a histopathological diagnosis of endometriosis. Genomic DNA was genotyped by nested-PCR, followed by digestion of the PCR product with the enzyme BstUI.Results The frequencies of the genotypes detected in the case and control groups were 22.4% GG, 52.2% AG and 25.4% AA; and 31.3% GG, 49.3% AG and 19.4% AA, respectively, with no significant difference between groups. The prevalence of the G allele was 48.5% and 56% in the case and control groups, respectively. No significant difference in genotype or allele frequency was detected between the different stages of endometriosis (p>0.05).Conclusions The results suggested that the Ser312Gly polymorphism of the HSD17β1 gene is not associated with endometriosis in Brazilian patients.
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- 2014
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21. Therapeutic Efficacy of Selenium Pre-treatment in Mitigating Cadmium-Induced Cardiotoxicity in Zebrafish (Danio rerio).
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Heuer RM, Falagan-Lotsch P, Okutsu J, Deperalto M, Koop RR, Umeh OG, Guevara GA, Noor MI, Covington MA, and Shelton DS
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Cardiovascular diseases are a rampant public health threat. Environmental contaminants, such as Cadmium (Cd), a toxic metal, have been linked to increased risk for cardiovascular diseases. Given that human exposure to Cd is increasing overtime, there is a need to develop new therapies to ameliorate Cd toxicity. Selenium (Se), an essential trace element, has been proposed to rescue the effects of Cd toxicity, with mixed effects. Se's narrow therapeutic window necessitates precise dosing to avoid toxicity. Here, we assessed the effects of various waterborne Cd and Se concentrations and sequences on cardiac function using zebrafish ( Danio rerio ). We showed that Cd induced pericardial edemas and modified heart rates in a concentration-dependent manner. To identify the therapeutic range of Se for Cd-induced cardiotoxicity, zebrafish embryos were treated with 0, 10, 50, 100, 150, or 200 μg/L Se for 1-4 days prior to exposure to Cd at 2.5, and 5 μg/L. We found that a 50 μg/L Se pre-treatment prior to Cd at 2.5 μg/L, but not at 5 μg/L, reduced the prevalence of pericardial edemas and ameliorated Cd-induced bradycardia in zebrafish. Embryos exposed to 10 and 50 μg/L of Se showed typical heart morphology, whereas other Se-exposed and Se-deficient fish presented pericardial edemas. Longer Se pre-treatment durations led to fewer incidences of pericardial edemas. Overall, this study highlights the importance of optimizing Se concentration and pre-treatment periods to harness its protective effects against Cd-induced cardiotoxicity. These findings provide insights into potential therapeutic strategies for reducing Cd-related cardiovascular damage in humans., Competing Interests: Declarations The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Delia S. Shelton reports financial support was provided by National Institutes of Health National Institute of Environmental Health Sciences.
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- 2024
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22. Mechanistic Insights into the Biological Effects of Engineered Nanomaterials: A Focus on Gold Nanoparticles.
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Nguyen NHA and Falagan-Lotsch P
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- Humans, Gold, Nanotechnology, Nanomedicine, Metal Nanoparticles, Nanoparticles, Nanostructures
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Nanotechnology has great potential to significantly advance the biomedical field for the benefit of human health. However, the limited understanding of nano-bio interactions leading to unknowns about the potential adverse health effects of engineered nanomaterials and to the poor efficacy of nanomedicines has hindered their use and commercialization. This is well evidenced considering gold nanoparticles, one of the most promising nanomaterials for biomedical applications. Thus, a fundamental understanding of nano-bio interactions is of interest to nanotoxicology and nanomedicine, enabling the development of safe-by-design nanomaterials and improving the efficacy of nanomedicines. In this review, we introduce the advanced approaches currently applied in nano-bio interaction studies-omics and systems toxicology-to provide insights into the biological effects of nanomaterials at the molecular level. We highlight the use of omics and systems toxicology studies focusing on the assessment of the mechanisms underlying the in vitro biological responses to gold nanoparticles. First, the great potential of gold-based nanoplatforms to improve healthcare along with the main challenges for their clinical translation are presented. We then discuss the current limitations in the translation of omics data to support risk assessment of engineered nanomaterials.
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- 2023
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23. Cytotoxicity of mini gold nanorods: intersection with extracellular vesicles.
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Nunes ÁM, Falagan-Lotsch P, Roslend A, Meneghetti MR, and Murphy CJ
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It is well-known that there are size- and shape-dependencies to nanoparticle uptake and processing by living cells. Small gold nanorods have shown to exhibit low toxicity and high clearance rates when compared to larger ones, making smaller particles more desirable for biomedical applications. In this study gold mini-rods (approximately 9.5 × 23, 8 × 26, and 6 × 26 nm, corresponding to aspect ratios 2.5, 3.2 and 4.1) and gold nanospheres (15.6 nm average diameter) were synthesized, and wrapped with cationic and anionic polyelectrolytes. This library of colloidally stable nanomaterials was exposed to human dermal fibroblasts at the relatively low concentration of 1 nM for each nanoparticle type. The cytotoxic profile of these nanoparticles and their influence on the small extracellular vesicles released by the cells was assessed. It was observed that although the nanoparticles were found in vesicles inside the cells, the cell viability, the mitochondrial membrane potential and levels of reactive oxygen species were not markedly affected by the mini gold nanorods. The production of extracellular vesicles by the cells was unaffected by gold nanoparticle exposure; moreover, no gold nanoparticles were observed in extracellular vesicles in the exosomal size range. Taken together, these results suggest that these mini gold nanorods are suitable for a wide range of cellular applications for relatively short-term studies., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)
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- 2022
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24. Network-based analysis implies critical roles of microRNAs in the long-term cellular responses to gold nanoparticles.
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Falagan-Lotsch P and Murphy CJ
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- Fibroblasts, Gene Expression Profiling, Gold, Humans, Metal Nanoparticles toxicity, MicroRNAs genetics
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Since gold nanoparticles (AuNPs) have great potential to bring improvements to the biomedical field, their impact on biological systems should be better understood, particularly over the long term, using realistic doses of exposure. MicroRNAs (miRNAs) are small noncoding RNAs that play key roles in the regulation of biological pathways, from development to cellular stress responses. In this study, we performed genome-wide miRNA expression profiling in primary human dermal fibroblasts 20 weeks after chronic and acute (non-chronic) treatments to four AuNPs with different shapes and surface chemistries at a low dose. The exposure condition and AuNP surface chemistry had a significant impact on the modulation of miRNA levels. In addition, a network-based analysis was employed to provide a more complex, systems-level perspective of the miRNA expression changes. In response to the stress caused by AuNPs, miRNA co-expression networks perturbed in cells under non-chronic exposure to AuNPs were enriched for target genes implicated in the suppression of proliferative pathways, possibly in attempt to restore cell homeostasis, while changes in miRNA co-expression networks enriched for target genes related to activation of proliferative and suppression of apoptotic pathways were observed in cells chronically exposed to one specific type of AuNPs. In this case, miRNA dysregulation might be contributing to enforce a new cell phenotype during stress. Our findings suggest that miRNAs exert critical roles in the cellular responses to the stress provoked by a low dose of NPs in the long term and provide a fertile ground for further targeted experimental studies.
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- 2020
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25. Poly-lactic acid nanoparticles (PLA-NP) promote physiological modifications in lung epithelial cells and are internalized by clathrin-coated pits and lipid rafts.
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da Luz CM, Boyles MS, Falagan-Lotsch P, Pereira MR, Tutumi HR, de Oliveira Santos E, Martins NB, Himly M, Sommer A, Foissner I, Duschl A, Granjeiro JM, and Leite PE
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- A549 Cells, Cell Survival, Clathrin chemistry, Drug Delivery Systems, Epithelial Cells cytology, Humans, Interleukin-12 metabolism, MicroRNAs metabolism, Particle Size, Pinocytosis, Proteome, Vascular Endothelial Growth Factor A metabolism, Biocompatible Materials chemistry, Caveolae metabolism, Epithelial Cells drug effects, Membrane Microdomains, Nanoparticles chemistry, Polyesters chemistry
- Abstract
Background: Poly-lactic acid nanoparticles (PLA-NP) are a type of polymeric NP, frequently used as nanomedicines, which have advantages over metallic NP such as the ability to maintain therapeutic drug levels for sustained periods of time. Despite PLA-NP being considered biocompatible, data concerning alterations in cellular physiology are scarce., Methods: We conducted an extensive evaluation of PLA-NP biocompatibility in human lung epithelial A549 cells using high throughput screening and more complex methodologies. These included measurements of cytotoxicity, cell viability, immunomodulatory potential, and effects upon the cells' proteome. We used non- and green-fluorescent PLA-NP with 63 and 66 nm diameters, respectively. Cells were exposed with concentrations of 2, 20, 100 and 200 µg/mL, for 24, 48 and 72 h, in most experiments. Moreover, possible endocytic mechanisms of internalization of PLA-NP were investigated, such as those involving caveolae, lipid rafts, macropinocytosis and clathrin-coated pits., Results: Cell viability and proliferation were not altered in response to PLA-NP. Multiplex analysis of secreted mediators revealed a low-level reduction of IL-12p70 and vascular epidermal growth factor (VEGF) in response to PLA-NP, while all other mediators assessed were unaffected. However, changes to the cells' proteome were observed in response to PLA-NP, and, additionally, the cellular stress marker miR155 was found to reduce. In dual exposures of staurosporine (STS) with PLA-NP, PLA-NP enhanced susceptibility to STS-induced cell death. Finally, PLA-NP were rapidly internalized in association with clathrin-coated pits, and, to a lesser extent, with lipid rafts., Conclusions: These data demonstrate that PLA-NP are internalized and, in general, tolerated by A549 cells, with no cytotoxicity and no secretion of pro-inflammatory mediators. However, PLA-NP exposure may induce modification of biological functions of A549 cells, which should be considered when designing drug delivery systems. Moreover, the pathways of PLA-NP internalization we detected could contribute to the improvement of selective uptake strategies.
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- 2017
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26. Successful Low-Cost Scaffold-Free Cartilage Tissue Engineering Using Human Cartilage Progenitor Cell Spheroids Formed by Micromolded Nonadhesive Hydrogel.
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Stuart MP, Matsui RAM, Santos MFS, Côrtes I, Azevedo MS, Silva KR, Beatrici A, Leite PEC, Falagan-Lotsch P, Granjeiro JM, Mironov V, and Baptista LS
- Abstract
The scaffold-free tissue engineering using spheroids is pointed out as an approach for optimizing the delivery system of cartilage construct. In this study, we aimed to evaluate the micromolded nonadhesive hydrogel (MicroTissues®) for spheroid compaction (2-day culture) and spontaneous chondrogenesis (21-day culture) using cartilage progenitors cells (CPCs) from human nasal septum without chondrogenic stimulus. CPC spheroids showed diameter stability (486 μ m ± 65), high percentage of viable cells (88.1 ± 2.1), and low percentage of apoptotic cells (2.3%). After spheroid compaction, the synthesis of TGF- β 1, TGF- β 2, and TGF- β 3 was significantly higher compared to monolayer ( p < 0.005). Biomechanical assay revealed that the maximum forces applied to spheroids after chondrogenesis were 2.6 times higher than for those cultured for 2 days. After spontaneous chondrogenesis, CPC spheroids were entirely positive for N-cadherin, collagen type II and type VI, and aggrecan and chondroitin sulfate. Comparing to monolayer, the expression of SOX5 and SOX6 genes analyzed by qPCR was significantly upregulated ( p < 0.01). Finally, we observed the capacity of CPC spheroids starting to fuse. To the best of our knowledge, this is the first time in the scientific literature that human CPC spheroids were formed by micromolded nonadhesive hydrogel, achieving a successful scaffold-free cartilage engineering without chondrogenic stimulus (low cost).
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- 2017
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27. One low-dose exposure of gold nanoparticles induces long-term changes in human cells.
- Author
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Falagan-Lotsch P, Grzincic EM, and Murphy CJ
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- Cell Cycle drug effects, Cells, Cultured, Fibroblasts cytology, Gene Expression Regulation drug effects, Gold chemistry, Gold pharmacology, Humans, Oxidative Stress drug effects, Polyethylene Glycols toxicity, Toxicity Tests, Acute, Toxicity Tests, Chronic, Fibroblasts drug effects, Gene Regulatory Networks drug effects, Gold toxicity, Metal Nanoparticles chemistry
- Abstract
We report the in vitro long-term (20 wk) changes in cells exposed to well-characterized gold nanoparticles (Au NPs) with varying shapes and surface coatings under both chronic (exposure to Au NPs continuously over 20 wk) and nonchronic (initial acute cell exposure to Au NPs, followed by 20 wk in NP-free cell media) conditions. Both chronic and nonchronic Au NPs exposures at low dose induce modifications at the gene level after long periods. In attempt to overcome from the injuries caused by nanoparticle exposure, genes related to oxidative stress, cell cycle regulation, and inflammation are among those presenting differential expression levels. Surprisingly, the nonchronic exposure induced more gene expression changes than its chronic counterpart and the stress effects caused by this type of exposure were sustained even after 20 wk without any additional NP exposure. NP surface chemistry played an important role in the alteration of gene regulation. Overall, our data suggest that (i) cells can adaptively respond to chronic, low-level NP insults; (ii) the cell stress response is not reversible over time upon removal of NPs upon acute, nonchronic exposure; and (iii) polyethylene glycol is not as benign a surface chemistry as is generally supposed., Competing Interests: The authors declare no conflict of interest.
- Published
- 2016
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28. Performance of PCR-based and Bioluminescent assays for mycoplasma detection.
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Falagan-Lotsch P, Lopes TS, Ferreira N, Balthazar N, Monteiro AM, Borojevic R, and Granjeiro JM
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- Mycoplasma genetics, Sensitivity and Specificity, Cell Culture Techniques standards, Luminescent Measurements methods, Mycoplasma isolation & purification, Polymerase Chain Reaction methods
- Abstract
Contaminated eukaryotic cell cultures are frequently responsible for unreliable results. Regulatory entities request that cell cultures must be mycoplasma-free. Mycoplasma contamination remains a significant problem for cell cultures and may have an impact on biological analysis since they affect many cell parameters. The gold standard microbiological assay for mycoplasma detection involves laborious and time-consuming protocols. PCR-based and Bioluminescent assays have been considered for routine cell culture screening in research laboratories since they are fast, easy and sensitive. Thus, the aim of this work is to compare the performance of two popular commercial assays, PCR-based and Bioluminescent assays, by assessing the level of mycoplasma contamination in cell cultures from Rio de Janeiro Cell Bank (RJCB) and also from customers' laboratories. The results obtained by both performed assays were confirmed by scanning electron microscopy. In addition, we evaluated the limit of detection of the PCR kit under our laboratory conditions and the storage effects on mycoplasma detection in frozen cell culture supernatants. The performance of both assays for mycoplasma detection was not significantly different and they showed very good agreement. The Bioluminescent assay for mycoplasma detection was slightly more dependable than PCR-based due to the lack of inconclusive results produced by the first technique, especially considering the ability to detect mycoplasma contamination in frozen cell culture supernatants. However, cell lines should be precultured for four days or more without antibiotics to obtain safe results. On the other hand, a false negative result was obtained by using this biochemical approach. The implementation of fast and reliable mycoplasma testing methods is an important technical and regulatory issue and PCR-based and Bioluminescent assays may be good candidates. However, validation studies are needed., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
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29. The functional EGF+61 polymorphism and nonsyndromic oral clefts susceptibility in a Brazilian population.
- Author
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Falagan-Lotsch P, Lopes TS, Küchler EC, Tannure PN, Costa Mde C, Amorim LM, and Granjeiro JM
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- Adolescent, Adult, Alcohol Drinking adverse effects, Brazil, Case-Control Studies, Child, Female, Gene Frequency, Genotype, Humans, Male, Polymerase Chain Reaction, Pregnancy, Risk Factors, Sex Factors, Smoking adverse effects, Young Adult, Cleft Lip genetics, Cleft Palate genetics, Epidermal Growth Factor genetics, Genetic Association Studies, Polymorphism, Restriction Fragment Length
- Abstract
Nonsyndromic oral clefts are considered a problem of public health in Brazil, presenting a multifactorial etiology that involves genetic and environmental components, such as maternal alcohol consumption. Several candidate genes have been investigated to identify some association with nonsyndromic clefts risk. The epidermal growth factor (EGF) gene is implicated in the normal craniofacial development and its functional +61 A>G polymorphism has been related to cancer susceptibility. It has been suggested that cancer and oral clefts may share the same molecular pathways.Objective Our goal was to evaluate the association between the EGF+61 A>G polymorphism and nonsyndromic oral clefts susceptibility.Material and Methods The case-control study included 218 cleft cases and 253 controls from Brazil. The control group was comprised of individuals without congenital malformations, dental anomalies and family history of clefts. The cleft phenotypes and subphenotypes were determined based on clinical examination. Genomic DNA was extracted from oral mucosa cells obtained by mouthwash. The EGF+61 A>G polymorphism genotype was determined by polymerase chain reaction-restriction fragment length polymorphism.Results We noticed the association between maternal alcohol consumption during pregnancy and cleft occurrence. The A allele and AA genotype were over-represented in cleft cases compared with control group when we considered the bilateral cleft lip with or without cleft palate (CL±P) cases, cleft cases with tooth agenesis and cleft cases presenting family history of cleft, but the differences were not statistically significant. Contradictorily, the G allele was higher in cleft palate only (CP) cases than in control group, showing a borderline p value. Comparing the different cleft phenotypes, we observed statistical differences between CP and CL±P cases. Our data suggest the EGF+61 A>G polymorphism was not related with nonsyndromic oral clefts susceptibility in a Brazilian population, but supported the different genetic background between CL±P and CP. Moreover, we confirmed the potential effect of maternal alcohol intake on cleft risk in our population.
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- 2015
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30. Buccal cells DNA extraction to obtain high quality human genomic DNA suitable for polymorphism genotyping by PCR-RFLP and Real-Time PCR.
- Author
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Küchler EC, Tannure PN, Falagan-Lotsch P, Lopes TS, Granjeiro JM, and Amorim LM
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- Adult, Analysis of Variance, Electrophoresis, Female, Humans, Male, Middle Aged, Reproducibility of Results, Saliva, Spectrophotometry, Time Factors, DNA isolation & purification, Genotyping Techniques methods, Mouth cytology, Polymorphism, Restriction Fragment Length genetics, Real-Time Polymerase Chain Reaction methods
- Abstract
Objective: The aim of this study was to evaluate, by PCR-RFLP and real-time PCR, the yield and quality of genomic DNA collected from buccal cells by mouthwash after different storage times at room temperature., Material and Methods: A group of volunteers was recruited to collect buccal cells using a mouthwash solution. The collected solution was divided into 3 tubes, one tube were used for immediate extraction and the remaining received ethanol and were kept at room temperature for 4 and 8 days followed by dna extraction. The concentration, purity and integrity of the dna were determined using spectrophotometry and electrophoresis. DNA quality differences among the three incubation times were also evaluated for genotyping EGF +61 a/g (rs 4444903) polymorphism by PCR-RFLP and for IRF6 polymorphism (rs 17015215) using real-time PCR., Results: There was no significant difference of dna yield (p=0.75) and purity (p=0.86) among the three different incubation times. DNA obtained from different incubation times presented high-molecular weight. The PCR-RFLP and real time pcr reactions were successfully performed for all DNA samples, even those extracted after 8 days of incubation. All samples genotyped by real-time pcr presented c allele for irf6 gene polymorphism (homozygous: cc; heterozygous: Ct) and the C allele was used as a reference for Ct values. The samples presented the same genotype for the different times in both techniques., Conclusion: We demonstrated that the method described herein is simple and low cost, and that DNA can be extracted and pcr amplified after storage in mouthwash solution at room temperature.
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- 2012
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31. Prognostic and predictive value of TP53 mutations in node-positive breast cancer patients treated with anthracycline- or anthracycline/taxane-based adjuvant therapy: results from the BIG 02-98 phase III trial.
- Author
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Fernández-Cuesta L, Oakman C, Falagan-Lotsch P, Smoth KS, Quinaux E, Buyse M, Dolci MS, Azambuja ED, Hainaut P, Dell'orto P, Larsimont D, Francis PA, Crown J, Piccart-Gebhart M, Viale G, Leo AD, and Olivier M
- Subjects
- Adenocarcinoma drug therapy, Adenocarcinoma genetics, Adenocarcinoma pathology, Adolescent, Adult, Aged, Antineoplastic Agents therapeutic use, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Apoptosis drug effects, Base Sequence, Breast Neoplasms pathology, Chemotherapy, Adjuvant, Disease-Free Survival, Docetaxel, Female, Humans, Ki-67 Antigen metabolism, Lymphatic Metastasis genetics, Middle Aged, Mutation, Missense, Receptor, ErbB-2 metabolism, Receptors, Estrogen metabolism, Receptors, Progesterone metabolism, Retrospective Studies, Sequence Analysis, DNA, Sequence Deletion, Survival Analysis, Young Adult, Breast Neoplasms drug therapy, Breast Neoplasms genetics, Doxorubicin therapeutic use, Genes, p53, Taxoids therapeutic use, Tumor Suppressor Protein p53 genetics
- Abstract
Introduction: Pre-clinical data suggest p53-dependent anthracycline-induced apoptosis and p53-independent taxane activity. However, dedicated clinical research has not defined a predictive role for TP53 gene mutations. The aim of the current study was to retrospectively explore the prognosis and predictive values of TP53 somatic mutations in the BIG 02-98 randomized phase III trial in which women with node-positive breast cancer were treated with adjuvant doxorubicin-based chemotherapy with or without docetaxel., Methods: The prognostic and predictive values of TP53 were analyzed in tumor samples by gene sequencing within exons 5 to 8. Patients were classified according to p53 protein status predicted from TP53 gene sequence, as wild-type (no TP53 variation or TP53 variations which are predicted not to modify p53 protein sequence) or mutant (p53 nonsynonymous mutations). Mutations were subcategorized according to missense or truncating mutations. Survival analyses were performed using the Kaplan-Meier method and log-rank test. Cox-regression analysis was used to identify independent predictors of outcome., Results: TP53 gene status was determined for 18% (520 of 2887) of the women enrolled in BIG 02-98. TP53 gene variations were found in 17% (90 of 520). Nonsynonymous p53 mutations, found in 16.3% (85 of 520), were associated with older age, ductal morphology, higher grade and hormone-receptor negativity. Of the nonsynonymous mutations, 12.3% (64 of 520) were missense and 3.6% were truncating (19 of 520). Only truncating mutations showed significant independent prognostic value, with an increased recurrence risk compared to patients with non-modified p53 protein (hazard ratio = 3.21, 95% confidence interval = 1.740 to 5.935, P = 0.0002). p53 status had no significant predictive value for response to docetaxel., Conclusions: p53 truncating mutations were uncommon but associated with poor prognosis. No significant predictive role for p53 status was detected., Trial Registration: ClinicalTrials.gov NCT00174655.
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- 2012
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32. XRCC1 gene polymorphisms in a population sample and in women with a family history of breast cancer from Rio de Janeiro (Brazil).
- Author
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Falagan-Lotsch P, Rodrigues MS, Esteves V, Vieira R, Amendola LC, Pagnoncelli D, Paixão JC, and Gallo CV
- Abstract
The X-ray repair cross-complementing Group1 (XRCC1) gene has been defined as essential in the base excision repair (BER) and single-strand break repair processes. This gene is highly polymorphic, and the most extensively studied genetic changes are in exon 6 (Arg194Trp) and in exon 10 (Arg399Gln). These changes, in conserved protein sites, may alter the base excision repair capacity, increasing the susceptibility to adverse health conditions, including cancer. In the present study, we estimated the frequencies of the XRCC1 gene polymorphisms Arg194Trp and Arg399Gln in healthy individuals and also in women at risk of breast cancer due to family history from Rio de Janeiro. The common genotypes in both positions (194 and 399) were the most frequent in this Brazilian sample. Although the 194Trp variant was overrepresented in women reporting familial cases of breast cancer, no statistically significant differences concerning genotype distribution or intragenic interactions were found between this group and the controls. Thus, in the population analyzed by us, variants Arg194Trp and Arg399Gln did not appear to have any impact on breast cancer susceptibility.
- Published
- 2009
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