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1.
Mol Biol Rep ; 51(1): 544, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38642153

RESUMO

BACKGROUND: Breast cancer is a highly heterogeneous solid tumor, posing challenges in developing targeted therapies effective for all mammary carcinoma subtypes. WT1 emerges as a promising target for breast cancer therapy due to its potential oncogenic role in various cancer types. Previous works have yielded inconsistent results. Therefore, further studies are needed to clarify the behavior of this complex gene in breast cancer. METHODS AND RESULTS: In this study, we examined WT1 expression in both Formalin Fixed Paraffin Embedded breast tumors (n = 41) and healthy adjacent tissues (n = 41) samples from newly diagnosed cases of ductal invasive breast cancer. The fold change in gene expression between the tumor and healthy tissue was determined by calculating 2-∆∆Ct. Disease-free survival analysis was computed using the Kaplan-Meier method. To identify the expression levels of different WT1 isoforms, we explored the ISOexpresso database. Relative quantification of the WT1 gene revealed an overexpression of WT1 in most cases. The percentage of patients surviving free of disease at 8 years of follow-up was lower in the group overexpressing WT1 compared to the group with down-regulated WT1. CONCLUSIONS: Interestingly, this overexpression was observed in all molecular subtypes of invasive breast cancer, underscoring the significance of WT1 as a potential target in all these subtypes. The observed WT1 down-expression in a few cases of invasive breast cancer, associated with better survival outcomes, may correspond to the down-regulation of a particular WT1-KTS (-) isoform: the WT1 A isoform (EX5-/KTS-). The co-expression of this WT1 oncogenic isoform with a regulated WT1- tumor suppressor isoform, such as the major WT1 F isoform (EX5-/KTS +), could also explain such survival outcomes. Due to its capacity to adopt dual roles, it becomes imperative to conduct individual molecular expression profiling of the WT1 gene. Such an approach holds great promise in the development of personalized treatment strategies for breast cancer.


Assuntos
Neoplasias da Mama , Proteínas WT1 , Feminino , Humanos , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Genes Supressores de Tumor , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas WT1/genética , Proteínas WT1/metabolismo
2.
Encephale ; 50(2): 178-184, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37718198

RESUMO

BACKGROUND AND STUDY AIM: Schizophrenia (SZ) is a multifactorial disorder involving complex interactions between genetic and environmental factors, where immune dysfunction plays a key etiopathogenic role. In order to explore the control of innate immune responses in SZ, we aimed to investigate the potential association between twelve TLR2, TLR4 and TLR9 variants (TLR2: rs4696480T>A, rs3804099T>C, rs3804100T>C; TLR4: rs1927914G>A, rs10759932T>C, rs4986790A>G, rs4986791T>C, rs11536889G>C, rs11536891T>C; TLR9: rs187084A>G, rs352139T>C and rs352140C>T) and SZ susceptibility in a Tunisian population. PATIENTS AND METHODS: This study included 150 patients and 201 healthy controls with no history of psychiatric illness. Genotyping was done using a TaqMan SNP genotyping assay. We also assessed a haplotype analysis for TLR2, TLR4 and TLR9 variants with SZ using Haploview 4.2 Software. RESULTS: We found that the AA genotype of the TLR2 rs4696480T>A variant was significantly associated with an increased risk of SZ (46% vs. 31%, P=4.7×10-3, OR=1.87 and 95% CI [1.18-2.97]). The frequency of the TA genotype was significantly higher in the control group than in SZ patients (27% vs. 43%, P=2.1×10-3) and may be associated with protection against SZ (OR=0.49 and 95% CI [0.30-0.80]). Whereas, the TLR9 rs187084-GG genotype was higher in the control group compared to patients (16% vs. 5%, P=1.6×10-3) and would present protection against SZ (OR=0.28, CI=[0.10-0.68]). The ACT haplotype of the TLR2 and the ACC haplotype of the TLR9 gene were identified as a risk haplotypes for SZ (P=0.04, OR=9.30, 95% CI=[1.11-77.71]; P=3×10-4, OR=6.05, 95% CI=[2.29-15.98], respectively). CONCLUSION: The results indicate that TLR2 and TLR9 genetic diversity may play a role in genetic vulnerability to SZ. However, including more patients and evaluation of TLR2 and TLR9 expression are recommended.


Assuntos
Esquizofrenia , Receptor 2 Toll-Like , Humanos , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética , Receptor Toll-Like 9/genética , Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único/genética , Esquizofrenia/genética , Genótipo , Estudos de Casos e Controles
3.
Encephale ; 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38824045

RESUMO

OBJECTIVES: Schizophrenia (SZ) and bipolar disorders (BP) are chronic and severe neuropsychiatric diseases. These disorders are tightly related to immune deregulations. In the current study, we intended to replicate the previously reported involvement of the soluble HLA-E isoforms (sHLA-E) in the risk of developing the two conditions along with disease severity in a Tunisian population group. PATIENTS AND METHODS: One hundred and twenty-four patients with schizophrenia and 121 with bipolar disorder meeting the DSM-IV criteria along 111 healthy controls were included in this present case-control study. The soluble HLA-E isoforms circulating levels were measured using the ELISA method. The statistical analyses were performed using Kruskal-Wallis and Wilcoxon rank sum tests by R software and GraphPad prism 9. RESULTS: We found that the sHLA-E circulating levels were significantly higher in BP patients as compared to healthy controls (P<0.0001) and that such increases were mainly observed in patients during an acute phase of their disease (P<0.0001). In SZ patients, while we failed to observe an association with the levels of sHLA-E in the entire SZ sample, we found that high sHLA-E levels characterized stabilized patients in comparison with those during an acute episode (P=0.022). Finally, we did not observe any association between sHLA-E circulating levels and symptoms assessed by the classical clinical scales either in BP or SZ patients. CONCLUSION: Overall, the present findings replicate in a Tunisian population group the previously demonstrated implication of sHLA-E circulating levels in the risk of developing BP or SZ in a French patient cohort. Such replication allows to consider HLA-E as a potent and true inflammatory marker in the context of the two disorders.

4.
Pediatr Nephrol ; 38(1): 119-129, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35445972

RESUMO

BACKGROUND: Nephropathic cystinosis is an autosomal recessive disease caused by a mutation in the CTNS gene which encodes cystinosin, a lysosomal cystine transporter. The spectrum of mutations in the CTNS gene is not well defined in the North African population. Here, we investigated twelve patients with nephropathic cystinosis belonging to eight Tunisian families in order to analyze the clinical and genetic characteristics of Tunisian children with infantile nephropathic cystinosis. METHODS: Clinical data were collected retrospectively. Molecular analysis of the CTNS gene was performed by Sanger sequencing. RESULTS: We describe a new splicing mutation c.971-1G > C in the homozygous state in 6/12 patients which seems to be a founder mutation. The reported deletion of 23nt c.771_793 Del (p.Gly258Serfs*30) was detected in a homozygous state in one patient and in a heterozygous compound state with the c.971-1G > C mutation in 3/12 patients. Two of 12 patients have a deletion of exons 4 and 5 of the CTNS gene. None of our patients had the most common 57-kb deletion. CONCLUSIONS: The mutational spectrum in the Tunisian population is different from previously described populations. Thus, a molecular diagnostic strategy must be implemented in Tunisia, by targeting as a priority the common mutations described in this country. Such a strategy will allow a cost-effective diagnosis confirmation as well as early administration of treatment with oral cysteamine. A higher resolution version of the Graphical abstract is available as Supplementary information.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros , Cistinose , Criança , Humanos , Sistemas de Transporte de Aminoácidos Neutros/genética , Cistinose/tratamento farmacológico , Cistinose/etnologia , Cistinose/genética , Éxons/genética , Síndrome de Fanconi/genética , Estudos Retrospectivos
5.
PLoS Genet ; 16(5): e1008639, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453731

RESUMO

Hypertrophic cardiomyopathy (HCM) is characterized by thickening of the ventricular muscle without dilation and is often associated with dominant pathogenic variants in cardiac sarcomeric protein genes. Here, we report a family with two infants diagnosed with infantile-onset HCM and mitral valve dysplasia that led to death before one year of age. Using exome sequencing, we discovered that one of the affected children had a homozygous frameshift variant in Myosin light chain 2 (MYL2:NM_000432.3:c.431_432delCT: p.Pro144Argfs*57;MYL2-fs), which alters the last 20 amino acids of the protein and is predicted to impact the most C-terminal of the three EF-hand domains in MYL2. The parents are unaffected heterozygous carriers of the variant and the variant is absent in control cohorts from gnomAD. The absence of the phenotype in carriers and the infantile presentation of severe HCM is in contrast to HCM associated with dominant MYL2 variants. Immunohistochemical analysis of the ventricular muscle of the deceased patient with the MYL2-fs variant showed a marked reduction of MYL2 expression compared to an unaffected control. In vitro overexpression studies further indicate that the MYL2-fs variant is actively degraded. In contrast, an HCM-associated missense variant (MYL2:p.Gly162Arg) and three other MYL2 stop-gain variants (p.E22*, p.K62*, p.E97*) that result in loss of the EF domains are stably expressed but show impaired localization. The degradation of the MYL2-fs can be rescued by inhibiting the cell's proteasome function supporting a post-translational effect of the variant. In vivo rescue experiments with a Drosophila MYL2-homolog (Mlc2) knockdown model indicate that neither the MYL2-fs nor the MYL2:p.Gly162Arg variant supports normal cardiac function. The tools that we have generated provide a rapid screening platform for functional assessment of variants of unknown significance in MYL2. Our study supports an autosomal recessive model of inheritance for MYL2 loss-of-function variants in infantile HCM and highlights the variant-specific molecular differences found in MYL2-associated cardiomyopathy.


Assuntos
Miosinas Cardíacas/genética , Cardiomiopatia Hipertrófica/genética , Família , Mutação da Fase de Leitura , Cadeias Leves de Miosina/genética , Adulto , Animais , Animais Geneticamente Modificados , Cardiomiopatia Hipertrófica/classificação , Cardiomiopatia Hipertrófica/congênito , Cardiomiopatia Hipertrófica/patologia , Células Cultivadas , Consanguinidade , Drosophila , Evolução Fatal , Feminino , Genes Dominantes , Genes Recessivos , Heterozigoto , Humanos , Lactente , Morte do Lactente , Recém-Nascido , Masculino , Linhagem , Fenótipo , Irmãos
6.
Encephale ; 2023 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-37748985

RESUMO

OBJECTIVES: Schizophrenia is a complex and chronic neuropsychiatric disorder. Recent genome-wide association studies have identified several at risk genetic variants, including two single nucleotide polymorphisms, namely the rs10503253 and the rs1270942 respectively located in the CSMD1 and the CFB loci. The present case-control study was designed to assess potential associations between the two variants and the risk of developing schizophrenia and disease severity. Further we demonstrate the relationship between these variants and clinical characteristics in a population-group from Tunisia. PATIENTS AND METHODS: In total, 216 patients diagnosed with schizophrenia along with176 healthy controls were included in this case-control study. The molecular analysis of the two polymorphisms was performed using tetra the Primer Amplification Refractory Mutation System-Polymerase Chain method. The statistical analysis was done using Compare V2.1 software, and correlations between genetic results and clinical characteristics were examined by Kruskal-Wallis testing. RESULTS: The frequency of the rs10503253A allele was found significantly higher among patients with schizophrenia as compared to healthy controls and associated with high negative PANSS scores. While no association was found concerning the implication of the rs1270942 variant in schizophrenia risk, a positive correlation with high positive PANSS scores was further observed. CONCLUSION: The present finding confirms the previously reported association between the Cub and Sushi multiple Domain 1 rs10503253A allele and the risk to develop schizophrenia and identified the rs1270942 variant as a potential disease risk modifier. Such observations may be important for the definition of the susceptible immunogenetic background in North African individuals at risk to develop mental disorders.

7.
BMC Bioinformatics ; 22(1): 163, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33771096

RESUMO

BACKGROUND: Coronavirus Disease 2019 (COVID-19) is a viral pandemic disease that may induce severe pneumonia in humans. In this paper, we investigated the putative implication of 12 vaccines, including BCG, OPV and MMR in the protection against COVID-19. Sequences of the main antigenic proteins in the investigated vaccines and SARS-CoV-2 proteins were compared to identify similar patterns. The immunogenic effect of identified segments was, then, assessed using a combination of structural and antigenicity prediction tools. RESULTS: A total of 14 highly similar segments were identified in the investigated vaccines. Structural and antigenicity prediction analysis showed that, among the identified patterns, three segments in Hepatitis B, Tetanus, and Measles proteins presented antigenic properties that can induce putative protective effect against COVID-19. CONCLUSIONS: Our results suggest a possible protective effect of HBV, Tetanus and Measles vaccines against COVID-19, which may explain the variation of the disease severity among regions.


Assuntos
Antígenos Virais/imunologia , SARS-CoV-2/química , Proteínas Virais/imunologia , Vacinas Virais/imunologia , Vacina BCG , COVID-19 , Vacinas contra COVID-19 , Simulação por Computador , Proteção Cruzada , Humanos , Conformação Proteica
8.
Genomics ; 112(6): 4189-4202, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32645523

RESUMO

Coronaviruses are responsible on respiratory diseases in animal and human. The combination of numerical encoding techniques and digital signal processing methods are becoming increasingly important in handling large genomic data. In this paper, we propose to analyze the SARS-CoV-2 genomic signature using the combination of different nucleotide representations and signal processing tools in the aim to identify its genetic origin. The sequence of SARS-CoV-2 was compared with 21 relevant sequences including Bat, Yak and Pangolin coronavirus sequences. In addition, we developed a new algorithm to locate the nucleotide modifications. The results show that the Bat and Pangolin coronaviruses were the most related to SARS-CoV-2 with 96% and 86% of identity all along the genome. Within the S gene sequence, the Pangolin sequence presents local highest nucleotide identity. Those findings suggest genesis of SARS-Cov-2 through evolution from Bat and Pangolin strains. This study offers new ways to automatically characterize viruses.


Assuntos
Quirópteros/virologia , Coronavirus/genética , Genoma Viral/genética , Pangolins/virologia , Recombinação Genética , SARS-CoV-2/genética , Algoritmos , Animais , Genômica/métodos , Humanos
9.
Hum Mutat ; 39(12): 2097-2109, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30298535

RESUMO

In humans, mutations of Desert Hedgehog gene (DHH) have been described in patients with 46,XY gonadal dysgenesis (GD), associated or not with polyneuropathy. In this study, we describe two patients diagnosed with GD, both harboring novel DHH compound heterozygous mutations p.[Tyr176*];[Asn337Lysfs*24] and p.[Tyr176*];[Glu212Lys]. To investigate the functional consequences of p.(Asn337Lysfs*24) and p.(Glu212Lys) mutations, located within the C-terminal part of DHh on auto-processing, we performed in vitro cleavage assays of these proteins in comparison with Drosophila melanogaster Hedgehog (Hh). We found that p.(Glu212Lys) mutation retained 50% of its activity and led to a partially abolished DHh auto-processing. In contrast, p.(Asn337Lysfs*24) mutation resulted in a complete absence of auto-proteolysis. Furthermore, we found a different auto-processing profile between Drosophila Hh and human DHh, which suggests differences in the processing mechanism between the two species. Review of the literature shows that proven polyneuropathy and GD is associated with complete disruption of DHh-N, whereas disruption of the DHh auto-processing is only described with GD. We propose a model that may explain the differences between Schwann and Leydig cell development by autocrine versus paracrine DHh signaling. To our knowledge, this is the first study investigating the effect of DHH mutations on DHh in vitro auto-processing.


Assuntos
Proteínas de Drosophila/metabolismo , Disgenesia Gonadal 46 XY/genética , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Mutação , Animais , Pré-Escolar , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Disgenesia Gonadal 46 XY/metabolismo , Proteínas Hedgehog/química , Heterozigoto , Humanos , Masculino , Domínios Proteicos , Proteólise , Especificidade da Espécie , Adulto Jovem
10.
Int J Cancer ; 142(12): 2512-2517, 2018 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-29363114

RESUMO

Breast cancer is a genetic disease but the known genes explain a minority of cases. To elucidate the molecular basis of breast cancer in the Tunisian population, we performed exome sequencing on six BRCA1/BRCA2 mutation-negative patients with familial breast cancer and identified a novel frameshift mutation in RCC1, encoding the Regulator of Chromosome Condensation 1. Subsequent genotyping detected the 19-bp deletion in additional 5 out of 153 (3%) breast cancer patients but in none of 400 female controls (p = 0.0015). The deletion was enriched in patients with a positive family history (5%, p = 0.0009) and co-segregated with breast cancer in the initial pedigree. The mutant allele was lost in 4/6 breast tumors from mutation carriers which may be consistent with the hypothesis that RCC1 dysfunction provides a selective disadvantage at the stage of tumor progression. In summary, we propose RCC1 as a likely breast cancer susceptibility gene in the Tunisian population.


Assuntos
Neoplasias da Mama/genética , Proteínas de Ciclo Celular/genética , Predisposição Genética para Doença/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Proteínas Nucleares/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Exoma/genética , Feminino , Mutação da Fase de Leitura , Estudos de Associação Genética , Genótipo , Humanos , Pessoa de Meia-Idade , Linhagem , Tunísia
11.
Tunis Med ; 96(3): 209-218, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30325490

RESUMO

INTRODUCTION: Clopidogrel (clopi) is a prodrug widely prescribed in the management of coronary artery disease and requires the intervention of hepatic cytochrome P450 2C19 (CYP2C19) for its activation. However, there is interindividual variability in response to clopi despite the use of recommended doses. Thus, the studies have highlighted the effect of the CYP2C19 gene polymorphism or Cyp2C19 gene on the response to clopi and particularly Cyp2C19 * 2 which may be associated with an increased risk of major cardiovascular events or MACE. OBJECTIVE: To evaluate the effect of Cyp2C19 * 2 polymorphism on MACE occurrence and hemorrhagic complications in patients treated with clopi. METHODS: We carried out a descriptive longitudinal study including 71 patients placed under clopi for a minimum duration of one month. Genotyping of the Cyp2C19 allele was performed by conventional polymerase chain reaction (PCR). After a follow-up period of 495 ± 183 days, we performed a statistical analysis to evaluate the association between the Cyp2C19 * 2 polymorphism and the occurrence of MACE or hemorrhagic complications. RESULTS: Among our patients, 51% had an angioplasty, 42% medical treatment and 7% a coronary artery bypass surgery. In our study population, 52% were heterozygous (HTZ), 28% homozygous (HMZ) healthy * 1 / * 1 and 20% HMZ had the loss of function allele * 2 / * 2. The allelic frequency of Cyp2C19 * 2 was 46%. Follow-up mean duration was of 495 ± 183 days. During this period, the prevalence of MACE was 11% and that of hemorrhagic complications was 13%. In our study, we did not observe a significant association between the occurrence of MACE or hemorrhagic complications with the genotype carrying the Cyp2C19 * 2 allele. CONCLUSION: Among patients treated with clopi, wearing a Cyp2C19 * 2 function loss allele didn't seem to be associated with a significantly higher risk of MACE, nor a significantly lower risk of hemorragic complications. This suggests the necessity of larger studies.


Assuntos
Clopidogrel/uso terapêutico , Citocromo P-450 CYP2C19/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/genética , Clopidogrel/farmacocinética , Doença da Artéria Coronariana/tratamento farmacológico , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Técnicas de Genotipagem , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Heterozigoto , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Testes Farmacogenômicos , Polimorfismo Genético , Tunísia/epidemiologia
12.
Tunis Med ; 95(12): 229-236, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29878286

RESUMO

BACKGROUND: The identification essentially of hMSH2 and/or hMLH1 alterations has clinical implications for recognition and prognosis of MSI phenotypes cases. In this study, we tried to identify instability by immunohistochemical expression pattern analysis, compared the results with molecular investigation and shown their usefulness as predictive factors for determination of Microsatellite Instability in patients with colorectal carcinomas in routinely. METHODS: Forty seven colorectal cancers and their adjacent colonic mucosa were selected retrospectively for this study. We first studied the potential value of molecular investigation to identify microsatellite instability in which a NCI panel (or Bethesda panel) of five microsatellite was analyzed (Bat-25, Bat-26, D2S123, D5S346 and D17S250). Secondary, we evaluated the immunohistochemical assessment of hMLH1, hMSH2, hMSH6 and PMS2 proteins in tumor and adjacent normal colorectal mucosa tissues. RESULTS: Fourteen cases were scored as MSI and the remaining MSS. Moreover, we found loss of expression for hMLH1, hMSH2, hMSH6 and PMS2 respectively in 9, 10, 6 and 9 of cases. The MSI patients were less than 45 years old, have right localization and mucinous histological type. We found an association between MSH2, age (P=0.03) and staging (P=0.02). MLH1 is associated only with age (P=0.02) while MSH6 with tumor grade (P=0.01). CONCLUSIONS: We found an association between MSI molecular investigation and MMR immunohistochemical expression which may allow one to specifically identify MSI phenotype of patients with colorectal carcinomas. Furthermore, immunohistochemical analysis of MMR protein can be used in routinely for detection of microsatellite instability without occurs to molecular investigation.


Assuntos
Neoplasias Colorretais/genética , Testes Genéticos/métodos , Imuno-Histoquímica/métodos , Instabilidade de Microssatélites , Técnicas de Diagnóstico Molecular/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/diagnóstico , Análise Mutacional de DNA/métodos , Feminino , Mutação em Linhagem Germinativa , Humanos , Masculino , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Endonuclease PMS2 de Reparo de Erro de Pareamento/metabolismo , Proteína 1 Homóloga a MutL/genética , Proteína 1 Homóloga a MutL/metabolismo , Proteína 2 Homóloga a MutS/genética , Proteína 2 Homóloga a MutS/metabolismo , Fenótipo , Reação em Cadeia da Polimerase/métodos , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Adulto Jovem
13.
J Theor Biol ; 403: 188-196, 2016 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-27211102

RESUMO

The significance of many BRCA unclassified variants (UVs) has not been evaluated. Classification of these variations as neutral or pathogenic presents a significant challenge and has important implications for breast and ovarian cancer genetic counseling. Here we report a combined molecular and computational approach to classify BRCA UVs missense variations. By using the LOH (Loss of heterozygosity) analysis at the BRCA1/BRCA2 loci, five bioinformatics approaches namely fathmm, PhD-SNP, SNAP, MutationTaster and Human Splicing Finder and the association with the clinico-pathological characteristics related to BRCA tumors, we were able to classify the R2787H (in BRCA2 gene) variant as pathogenic. Then, to investigate the functional role of the R2787H variation in altering BRCA2 structure, the homology model of this variant was constructed using the Rattus norvegicus BRCA2 (PDB ID: 1IYJ) as a template. The predicted model was then assessed for stereochemical quality and side chain environment. Furthermore, docking and binding free energy simulations were performed to investigate the ssDNA-BRCA2 complex interaction. Binding energy value calculation proves that this substitution affects the complex stability. Moreover, this alteration was not found in one hundred healthy controls. These findings suggest that R2787H variant could have potential functional impact. Our approach might be useful for evaluation of BRCA unclassified variants. However additional functional analyzes may provide appropriate assessment to classify such variants.


Assuntos
Neoplasias da Mama/genética , Genes BRCA2 , Predisposição Genética para Doença , Simulação de Acoplamento Molecular , Mutação de Sentido Incorreto/genética , Homologia Estrutural de Proteína , Sequência de Aminoácidos , Animais , Proteína BRCA2/química , Proteína BRCA2/genética , Estudos de Casos e Controles , Feminino , Loci Gênicos , Mutação em Linhagem Germinativa/genética , Humanos , Perda de Heterozigosidade/genética , Repetições de Microssatélites/genética , Ratos , Reprodutibilidade dos Testes , Alinhamento de Sequência
14.
Hum Hered ; 80(2): 69-78, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26540120

RESUMO

OBJECTIVE: Estimating the total allele frequency of all pathogenic alleles of an autosomal recessive disease is not possible if only mutational data of a sample of affected individuals are available. However, if the affected individuals come from a population where consanguinity is not uncommon, this total allele frequency can be estimated by additionally using the positive individual inbreeding coefficients or an estimate of the population inbreeding coefficient. In this paper, we propose two estimators. METHODS/RESULTS: We propose to estimate the total allele frequency by a conditional maximum likelihood estimator if a part of the affected individuals in the sample comes from consanguineous marriages with known inbreeding coefficients. A simulation study shows that this estimator is unbiased and robust. We propose a second estimator which is based on an estimate of the population inbreeding coefficient. The method is applied to mutational data and individual inbreeding coefficients of Tunisian patients with congenital adrenal hyperplasia. CONCLUSION: Additionally using individual inbreeding coefficients or an estimate of the population inbreeding coefficient makes it possible to estimate the total allele frequency. Since consanguinity is commonly practiced in many parts of the world, the estimators proposed in the paper are of practical importance.


Assuntos
Consanguinidade , Frequência do Gene , Genes Recessivos , Predisposição Genética para Doença/genética , Hiperplasia Suprarrenal Congênita/genética , Alelos , Humanos , Funções Verossimilhança , Mutação , Tunísia
15.
Tumour Biol ; 36(11): 8703-13, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26047604

RESUMO

Alterations in telomere dynamics have emerged as having a causative role in carcinogenesis. Both the telomere attrition contribute to tumor initiation via increasing chromosomal instability and that the telomere elongation induces cell immortalization and leads to tumor progression. The objectives of this study are to investigate the dynamics of telomere length in colorectal cancer (CRC) and the clinicopathological parameters implicated. We measured the relative telomere length (RTL) in cancerous tissues and in corresponding peripheral blood leukocytes (PBL) using quantitative PCR (Q-PCR) from 94 patients with CRC. Telomere length correlated significantly in cancer tissues and corresponding PBL (r = 0.705). Overall, cancer tissue had shorter telomeres than PBL (p = 0.033). In both cancer tissue and PBL, the RTL was significantly correlated with age groups (p = 0.008 and p = 0.012, respectively). The RTL in cancer tissue was significantly longer in rectal tumors (p = 0.04) and in the late stage of tumors (p = 0.01). In PBL, the RTL was significantly correlated with the macroscopic aspect of tumors (p = 0.02). In addition, the telomere-length ratio of cancer to corresponding PBL increased significantly with late-stage groups. Shortening of the telomere was detected in 44.7%, elongation in 36.2%, and telomeres were unchanged in 19.1% of 94 tumors. Telomere shortening occurred more frequently in the early stage of tumors (p = 0.01). This study suggests that the telomere length in PBL is affected by the macroscopic aspect of tumors and that telomere length in cancer tissues is a marker for progression of CRC and depends on tumor-origin site.


Assuntos
Instabilidade Cromossômica/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Homeostase do Telômero/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/classificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Telomerase/genética , Telômero/genética , Tunísia
16.
J Biosoc Sci ; 47(6): 718-26, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25630711

RESUMO

Consanguineous unions are a deeply rooted social practice among traditional societies. Despite their presumed social advantages, they can result in several health conditions. The aim of this study was: i) to compare consanguinity levels between Tunisian patients affected with autosomal recessive disorders (ARDs) and those with a chromosomal abnormality; and ii) to gain more insight into the mutational status of patients affected with ARDs. Data were collected from 290 files of patients affected by one of five ARDs confirmed by molecular analysis and 248 files of patients with confirmed Down syndrome. Information on the disease, mutation defining the disease, parents' relatedness and geographical origin was gathered. Consanguinity was found among 58% of the ARD patients and among 22% of Down syndrome patients, and a homozygous status was found in 90% of the patients born to related parents and in 70% of patients born to unrelated parents. Also, children from unrelated parents from the same geographical background were found to be more frequently affected by homozygous mutations than those from unrelated parents from different geographical backgrounds. The present study shows how marriage practices affect patterns of genetic variations and how they can lead to homogenization in the genetic pool.


Assuntos
Consanguinidade , Síndrome de Down/etnologia , Síndrome de Down/genética , Doenças Genéticas Inatas/etnologia , Doenças Genéticas Inatas/genética , Adulto , Criança , Pré-Escolar , Família , Feminino , Doenças Genéticas Inatas/epidemiologia , Variação Genética , Heterozigoto , Homozigoto , Humanos , Masculino , Casamento , Mutação , Linhagem , Tunísia/epidemiologia
17.
Tunis Med ; 102(2): 100-106, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38567476

RESUMO

INTRODUCTION: The Toll-like receptor 4 (TLR4), an important member of the host's innate immune response, is coded by a polymorphic gene. This polymorphism could be a predisposing factor for NasoPharyngeal Carcinoma (NPC). AIM: To determine the association between TLR4 gene polymorphisms and the susceptibility to NPC in a cohort of Tunisian affected patients. METHODS: Genomic DNAs from 245 unrelated patients affected by undifferentiated carcinoma type (UCNT) and 264 unrelated healthy controls were genotyped for the five single nucleotides polymorphisms (SNPs) of TLR4 locus (4434 A>G (rs1927914),7263 G>C (rs10759932), 6134 A>G(rs4986790), 8851C>T (rs 4986791), 5272 T>C(rs11536889), +8469 T>C (rs11536891)) by Taqman® 5'-nuclease assay. RESULTS: Among all polymorphisms studied, only the rs4986790 G and rs4986791 T alleles were significantly more prevalent in patients' group than controls (45% vs. 38%; p=0.03; pc=0.06) and increased the risk of the NPC (OR=1.3, 95% CI=1.01-1.69). Also, we found that the frequency of the rs4986790 AA and rs4986791 TT genotypes was significantly higher in controls than in patients (25.7% vs 37%; p=0.006, pc=0.02) and conferred a protector factor in NPC (OR= 0.59, 95% CI= 0.39-0.87). Further, based on the Kaplan-Meier survival curve we observed also the positive effect ofrs1927914 AA genotype on a prognostic of NPC (p=0.006; pc=0.01). CONCLUSION: Our study demonstrated that impaired production of TLR4 seems to be a risk factor of NPC development but functional studies are needed to confirm these findings. As to rs1927914 AA appears to be a good biomarker for better survival in a patient with NPC.


Assuntos
Predisposição Genética para Doença , Neoplasias Nasofaríngeas , Humanos , Estudos de Casos e Controles , Genótipo , Carcinoma Nasofaríngeo/epidemiologia , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/epidemiologia , Neoplasias Nasofaríngeas/genética , Receptor 4 Toll-Like/genética
18.
Int Immunopharmacol ; 122: 110665, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37487262

RESUMO

BACKGROUND/AIM: Type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD) have a significant impact on the expression of genes in peripheral blood mononuclear cells (PBMCs). The primary objective of this study was to investigate the role of two signaling pathways, STAT1/6, and two important modulators of immunometabolism, leptin and PPARs, in the development of T2DM with and without CVD. Furthermore, the study aimed to assess the correlation between these factors and the dynamics of CD14 in PBMCs. This research was conducted within the context of a growing body of literature on the complex pathophysiology of T2DM and its association with CVD. Prior studies have indicated that T2DM is characterized by an imbalance in immunometabolism and the involvement of various signaling pathways. MATERIALS AND METHODS: Blood samples were collected from a total of 47 subjects, including 7 healthy volunteers, 20 individuals diagnosed with diabetes and cardiovascular disease (D.CVD) and another 20 individuals diagnosed with diabetes only (D). PBMCs were isolated from these samples, and the expression levels of leptin, PPARγ, PPARα, and CD14 genes were measured using Real-Time PCR. RESULTS: The most relevant result showed that diabetic patients with CVD had significantly higher levels of leptin expression, which was positively correlated with STAT1 (r = 0.7497, p = 0.0001). On the other hand, diabetic patients without CVD had elevated PPARγ expression, which was strongly correlated with STAT6 (r = 0.8437, p = 0.0001). Interestingly, we found a significant increase in the PPARγ/ PPARα ratio in the D.CVD group compared to the D group (4.273 ± 0.9531; 7.52 ± 3.556, p = 0.0479). Moreover, CD14 expression was significantly reduced in this group compared to diabetic patients without CVD. CONCLUSION: These findings suggested that the immunometabolic imbalance in T2DM was driven by a STAT1/Leptin phenotype in diabetic patients with CVD and by a STAT6/PPARγ phenotype in diabetic patients without CVD. Taking into account STAT1/Leptin and STAT6/PPARγ profiling could help clinicians identify novel therapeutic targets for T2DM and other related diseases.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/genética , Doenças Cardiovasculares/genética , Leptina/genética , PPAR gama/genética , Leucócitos Mononucleares , PPAR alfa , Fenótipo , RNA Mensageiro
19.
J Clin Neurol ; 18(2): 214-222, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35196747

RESUMO

BACKGROUND AND PURPOSE: Warburg Micro syndrome (WARBM) is a rare autosomal recessive genetic disease characterized by ocular, neurologic, and endocrine anomalies. WARBM is a phenotypically and genetically heterogeneous syndrome caused by mutations in RAB3GAP1, RAB3GAP2, RAB18, and TBC1D20. Here we present the clinical and genetic characterization of a consanguineous Tunisian family with a WARBM phenotype presenting two pathogenic variations, one of which is on RAB3GAP1. METHODS: We applied whole-exome sequencing (WES) to two affected young males presenting a WARBM-compatible phenotype. RESULTS: We reveal a new variation in RAB3GAP1 (NM_012233.3: c.297del, p.Gln99fs) and another variation in ABCD1 (NM_000033: c.896A>G, p.His299Arg). Each of these mutations, which in silico predictions concluded as being pathogenic variations, affects a critical protein region. Both affected males presented a WARBM-compatible phenotype, with severe intellectual disability, severe developmental delay, postnatal growth delay, postnatal microcephaly, congenital bilateral cataracts, general hypotonia, and a thin corpus callosum without a splenium. However, intrafamilial clinical heterogeneity was present, since only the oldest child had large ears, microphthalmia, foot deformities, and a genital anomaly, and only the youngest child had microcornea. Despite the mutation identified in ABCD1, our patients did not have any X-linked symptoms of adrenoleukodystrophy disorder that are usually caused by ABCD1 mutations, which prompted our interest in clinical monitoring. CONCLUSIONS: WES analysis of a consanguineous Tunisian family with WARBM revealed a novel variation in RAB3GAP1 (NM_012233.3: c.297del, p.Gln99fs) that is most likely pathogenic and allowed us to confirm the diagnosis of WARBM.

20.
Infect Genet Evol ; 102: 105300, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35552003

RESUMO

Since the beginning of the Coronavirus disease-2019 pandemic, there has been a growing interest in exploring SARS-CoV-2 genetic variation to understand the origin and spread of the pandemic, improve diagnostic methods and develop the appropriate vaccines. The objective of this study was to identify the SARS-CoV-2s lineages circulating in Tunisia and to explore their amino acid signature in order to follow their genome dynamics. Whole genome sequencing and genetic analyses of fifty-eight SARS-CoV-2 samples collected during one-year between March 2020 and March 2021 from the National Influenza Center were performed using three sampling strategies.. Multiple lineage introductions were noted during the initial phase of the pandemic, including B.4, B.1.1, B.1.428.2, B.1.540 and B.1.1.189. Subsequently, lineages B1.160 (24.2%) and B1.177 (22.4%) were dominant throughout the year. The Alpha variant (B.1.1.7 lineage) was identified in February 2021 and firstly observed in the center of our country. In addition, A clear diversity of lineages was observed in the North of the country. A total of 335 mutations including 10 deletions were found. The SARS-CoV-2 proteins ORF1ab, Spike, ORF3a, and Nucleocapsid were observed as mutation hotspots with a mutation frequency exceeding 20%. The 2 most frequent mutations, D614G in S protein and P314L in Nsp12 appeared simultaneously and are often associated with increased viral infectivity. Interestingly, deletions in coding regions causing consequent deletions of amino acids and frame shifts were identified in NSP3, NSP6, S, E, ORF7a, ORF8 and N proteins. These findings contribute to define the COVID-19 outbreak in Tunisia. Despite the country's limited resources, surveillance of SARS-CoV-2 genomic variation should be continued to control the occurrence of new variants.


Assuntos
COVID-19 , SARS-CoV-2 , Aminoácidos/genética , COVID-19/epidemiologia , Genoma Viral , Humanos , Mutação , Filogenia , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Tunísia/epidemiologia
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