Systematic review of the molecular basis of hereditary breast and ovarian cancer syndrome in Brazil: the current scenario.

BACKGROUND: A detailed understanding of the genetic basis of cancer is of great interest to public health monitoring programs. Although many studies have been conducted in Brazil, a global view on the molecular profile related to hereditary breast and ovarian cancer (HBOC) in this large and heterogeneous population is lacking. METHODS: A systematic review following the PRISMA guidelines was conducted in three electronic databases (PubMed, BIREME and SciELO). Brazilian studies covering molecular analysis of genes related to HBOC, published until December 2023, were considered. RESULTS: We identified 35 original studies that met all the inclusion criteria. A total of 137 distinct mutations were found in the BRCA1 gene, but four of them corresponded to 44.5% of all mutations found in this gene. The c.5266dupC BRCA1 mutation was responsible for 26.8% of all pathogenic mutations found in the BRCA1 gene in patients with clinical criteria for HBOC from the Brazilian population. Considering all studies that track this mutation in the BRCA1 gene, we found a frequency of 2% (120/6008) for this mutation in Brazilian patients. In the BRCA2 gene, the four most frequent mutations corresponded to 29.2% of pathogenic mutations. Even though it was tracked by few studies, the c.156_157insAlu mutation was responsible for 9.6% of all pathogenic mutations reported in the BRCA2 gene. Seventeen studies found pathogenic mutations in other non-BRCA genes, the c.1010G > A mutation in the TP53 gene being the most frequent one. Considering all studies that screened for this specific mutation in patients with the clinical criteria for HBOC, the frequency of c.1010G > A was estimated at 1.83% (61/3336). CONCLUSIONS: Despite significant molecular heterogeneity among mutations in HBOC patients from Brazil, three mutations deserve to be highlighted, c.5266dupC, c.156_157insAlu and c.1010G > A in the BRCA1, BRCA2 and TP53 genes, respectively. With more than 200 records, these three mutations play a vital role in the pathology of breast and ovarian cancer in Brazil. The data collected shed light on the subject, but there is still not enough data from certain subpopulations.

Soluble DC-SIGN isoforms: Ligands with unknown functions - A mini-review.

The present study aimed to perform a mini-review of the complete soluble isoforms of Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin (sDC-SIGN), their functions, and their correlation with diseases. The present review reveals the lack of studies regarding these soluble isoforms and poor understanding of the importance of the topic, considering the concordant findings on the relevant influence of sDC-SIGN in the viral and bacterial infection process, in addition to its possible use as a cancer marker.

Assays with recombinant soluble isoforms of DC-SIGN, a dengue virus ligand, show variation in their ability to bind to mannose residues.

The DC-SIGN glycoprotein is responsible for the initial adhesion of dengue virus (DENV) to immune cells by the carbohydrate recognition domain (CRD). There are thirteen soluble and membrane-bound DC-SIGN isoforms, but the role of soluble isoforms in the DENV internalization process is not known. Five isoforms with an altered or absent CRD were identified, and three different soluble isoforms were used to confirm the interactions with mannose residues. The results show the loss of binding ability of one soluble isoform and binding ability of two of them. All of them will be used to verify their role in the DENV internalization process.

Mutation screening of TP53, CHEK2 and BRCA genes in patients at high risk for hereditary breast and ovarian cancer (HBOC) in Brazil.

BACKGROUND: Few studies related to hereditary breast and ovarian cancer syndrome (HBOC) have been conducted in Brazil, and they are restricted to only small areas of the country. Here, we report the mutation profile of BRCA1/2, CHEK2 and TP53 genes in a cohort from Minas Gerais state. METHODS: These genes from 44 patients at high risk for HBOC were screened through high-resolution melting and/or sequencing. The pathogenicity of the alterations was checked using ClinVar database and bioinformatics programs. RESULTS: In BRCA genes we identified 46 variants, 38 without clinical significance and 8 pathogenic mutations including a new pathogenic mutation in BRCA1 gene (c.4688_4694delACCTGGAinsG). The most prevalent pathogenic mutation was c.4829_4830delTG, in the BRCA2 gene. This mutation was not described in the Brazilian population up to now and in this study, it was described with a prevalence of 6.8%. The p.R337H mutation in TP53 gene was found in one patient clinically diagnosed as HBOC and without clinical criteria for Li-Fraumeni syndrome. In CHEK2 gene, the undescribed variant c.485A > G was found and it presents as probably pathogenic through in silico analyses. Pathogenic mutations were found in 29.5% of the patients, 11.3% in BRCA1, 15.9% in BRCA2 and 2.3% in TP53 gene. CONCLUSIONS: Brazilian population is one of the most heterogeneous in the world and the mutational profile knowledge of genes related to HBOC from different regions can contribute to the definition of more cost-effective strategies for the prevention, identification and treatment of cancer.

Rational selection of immunodominant and preserved epitope Sm043300e from Schistosoma mansoni and design of a chimeric molecule for biotechnological purposes.

Human schistosomiasis is a neglected tropical disease of great importance in public health. A large number of people are infected with schistosomiasis, making vaccine development and effective diagnosis important control strategies. A rational epitope prediction workflow using Schistosoma mansoni hypothetical proteins was previously presented by our group, and an improvement to that approach is presented here. Briefly, immunodominant epitopes from parasite membrane proteins were predicted by reverse vaccinology strategy with additional in silico analysis. Furthermore, epitope recognition was evaluated using sera of individuals infected with S. mansoni. The epitope that stood out in both in silico and in vitro assays was used to compose a rational chimeric molecule to improve immune response activation. Out of 2185 transmembrane proteins, four epitopes with high binding affinities for human and mouse MHCII molecules were selected through computational screening. These epitopes were synthesized to evaluate their ability to induce TCD4+ lymphocyte proliferation in mice. Sm204830e and Sm043300e induced significant TCD4+ proliferation. Both epitopes were submitted to enzyme-linked immunosorbent assay to evaluate their recognition by IgG antibodies from the sera of infected individuals, and epitope Sm043300 was significantly recognized in most sera samples. Epitope Sm043300 also showed good affinity for human MHCII molecules in molecular docking, and its sequence is curiously highly conserved in four S. mansoni proteins, all of which are described as G-protein-coupled receptors. In addition, we have demonstrated the feasibility of incorporating this epitope, which showed low similarity to human sequences, into a chimeric molecule. The stability of the molecule was evaluated by molecular modeling aimed at future molecule production for use in diagnosis and vaccination trials.

Pharmacophoric characteristics of dengue virus NS2B/NS3pro inhibitors: a systematic review of the most promising compounds.

Dengue virus (DENV) infection can lead to a wide range of clinical manifestations, including fatal hemorrhagic complications. There is a need to find effective pharmacotherapies to treat this disease due to the lack of specific immunotherapies and antiviral drugs. That said, the DENV NS2B/NS3pro protease complex is essential in both the viral multiplication cycle and in disease pathogenesis, and is considered a promising target for new antiviral therapies. Here, we performed a systematic review to evaluate the pharmacophoric characteristics of promising compounds against NS2B/NS3pro reported in the past 10 years. Online searches in the PUBMED/MEDLINE and SCOPUS databases resulted in 165 articles. Eight studies, which evaluated 3,384,268 molecules exhibiting protease inhibition activity, were included in this review. These studies evaluated anti-dengue activity in vitro and the IC50 and EC50 values were provided. Most compounds exhibited non-competitive inhibition. Cytotoxicity was evaluated in BHK-21, Vero, and LLC-MK2 cells, and the CC50 values obtained ranged from < 1.0 to 780.5 µM. Several groups were associated with biological activity against dengue, including nitro, catechol, halogen and ammonium quaternaries. Thus, these groups seem to be potential pharmacophores that can be further investigated to treat dengue infections.

Molecular surveillance of dengue in Minas Gerais provides insights on dengue virus 1 and 4 circulation in Brazil.

Dengue, caused by any of the four types of Dengue virus (DENV) is the most important arbovirus in the world. In this study we performed a molecular surveillance of dengue during the greatest dengue outbreak that took place in Divinópolis, Minas Gerais state, Southeast Brazil, in 2013. Samples from 100 patients with clinical symptoms of dengue were studied and 26 were positive. The capsid/premembrane (CprM) and envelope gene sequences of some samples were amplified and sequenced. Molecular analyses demonstrated that two DENV-1 lineages, belonging to genotype V were introduced and co-circulated in Divinópolis. When compared to each other, those lineages presented high genetic diversity and showed unique amino acids substitutions in the envelope protein, including in domains I, II, and III. DENV-4 strains from Divinópolis clustered within genotype IIb and the most recent common ancestor was probably introduced into the city three years before the 2013 epidemic. Here we demonstrated for the first time the circulation of DENV-4 and the co-circulation of two DENV-1 lineages in Midwest region of Minas Gerais, Brazil. Moreover our analysis indicated the introduction of five DENV-1 lineages, genotype V into Brazil, in different times. J. Med. Virol. 89:966-973, 2017. © 2016 Wiley Periodicals, Inc.

Demethylation profile of the TNF-α promoter gene is associated with high expression of this cytokine in Dengue virus patients.

Dengue is the most prevalent arthropod-borne viral illness in humans. The overexpression of cytokines by Dengue virus (DENV) infected cells is associated with the most severe forms of the disease. Unmethylated CpG islands are related to a transcriptionally active structure, whereas methylated DNA recruits methyl-binding proteins that inhibit gene expression. Several studies have described the importance of epigenetic events in the regulation and expression of many cytokines. The purpose of the present study was to evaluate the methylation status of the IFN-γ and TNF-α promoters in DNA extracted from dengue infected patients using methylation-specific polymerase chain reaction. A high frequency of demethylation was observed in the TNF-α promoter of DENV infected patients when compared to non-infected controls. The patients with an unmethylated profile showed higher expression of TNF-α mRNA than patients with the methylated status. No difference was found in the methylation frequency between the two analyzed groups regarding the IFN-γ promoter or in the expression of IFN-γ transcripts. The present study provides the first association of TNF-α promoter demethylation in DENV infected individuals and demonstrates a correlation between the methylation status of the region analyzed and the expression of TNF-α transcripts in DENV infected patients. J. Med. Virol. 88:1297-1302, 2016. © 2016 Wiley Periodicals, Inc.

Screening of the BRCA1 gene in Brazilian patients with breast and/or ovarian cancer via high-resolution melting reaction analysis.

The aim of this study was to evaluate the profile of BRCA1 mutations among cancer-affected Brazilian women from the Midwest region of Minas Gerais state with clearly defined risk factors for hereditary breast and ovarian cancer (HBOC) syndrome. In this Brazilian region, the first Center for Hereditary Cancer Control began operation in 2011, and 90% of patients receive assistance from the public health service. Eighteen patients at high risk for HBOC were subjected to molecular analysis. Primers were designed for 22 coding exons of the gene; DNA was extracted; and real-time PCR followed by high-resolution melting reaction was performed. The amplicons were sequenced to confirm the identified profiles. Only exon 11 was directly sequenced due its length. Multiplex ligation-dependent probe amplification (MLPA) was performed for those patients in whom no pathogenic mutations were found. Among the 14 alterations identified in this study, the c.5263_5264insC pathogenic mutation was present in two patients (11.1%). Four alterations showed no clinical relevance; one exhibited inconclusive clinical relevance according to the examined databases; and eight alterations presented a divergent classification between the databases. No deletions or duplications were found using the MLPA technique. The HRM methodology was highly sensitive in identifying variants in the BRCA1 gene and can dramatically reduce the amount of sequencing required to identify germline mutations in BRCA genes, enabling cheaper tests and increasing their availability to Brazilian women assisted by the public health service.

Dengue outbreaks in Divinopolis, south-eastern Brazil and the geographic and climatic distribution of Aedes albopictus and Aedes aegypti in 2011-2012.

OBJECTIVE: To entomologically monitor Aedes spp. and correlate the presence of these vectors with the recent epidemic of dengue in Divinopolis, Minas Gerais State, Brazil. METHODS: Ovitraps were installed at 44 points in the city, covering six urban areas, from May 2011 to May 2012. After collection, the eggs were incubated until hatching. In the 4th stage of development, the larvae were classified as Ae. aegypti or Ae. albopictus. RESULTS: In total, 25 633 Aedes spp. eggs were collected. February was the month with the highest incidence, with 5635 eggs collected and a hatching rate of 46.7%. Ae. aegypti eggs had the highest hatching rate, at 72.3%, whereas Ae. albopictus eggs had 27.7%. Climate and population density influenced the number of eggs found. Indicators of vector presence were positively correlated with the occurrence of dengue cases. CONCLUSION: These data reinforce the need for entomological studies, highlight the relevance of Ae. albopictus as a possible disease vector and demonstrate its adaptation. Ae. albopictus, most commonly found in forested areas, comprised a substantial proportion of the urban mosquito population.

Clinical, Molecular, and Epidemiological Analysis of Dengue Cases during a Major Outbreak in the Midwest Region of Minas Gerais, Brazil.

This study aims to perform the first molecular and clinical-epidemiological analysis of dengue cases in Divinopolis, MG, Brazil. Data from 4,110 cases of dengue were accessed and 190 clinical samples were collected for molecular analyses. In this study, 2.7% of the men and 3.0% of the women were admitted to hospital. There was no association between gender and hospital admission. The symptoms observed in this study are according to the Health Ministry, but fever was present in 82.2% and not in 100% of cases. The chance of hospital admission was 1.55 higher in patients with any kind of bleeding (334) and 2.4% of individuals without bleeding were also hospitalized due to other warning signs. In the molecular analyses, 23% of the samples were positive for DENV. DENV-2 and DENV-3 were identified in 2010, DENV-3 in 2011, DENV-1 in 2012, and DENV-1 and DENV-4 in 2013. DENV detection was possible in samples with only one day of symptoms. This first report of dengue data in Divinópolis provided more insight into the viral types and effects of disease in the city, confirming the need for caution in assessing cases of suspected dengue and for revision of the criteria proposed by the Health Ministry to classify cases of the disease.

Identification of a vaccine against schistosomiasis using bioinformatics and molecular modeling tools.

Schistosomiasis is a serious public health problem in Brazil and worldwide. Although the drugs used to treatment schistosomiasis are effective, the disease continues to expand in all endemic countries due to constant reinfection, poor sanitation, and the lack of effective programs for disease control. However, advances generated through genome projects have provided important information that has improved the understanding of the biology of this parasite. These advances, associated with the advent of bioinformatic analysis, are becoming an important tool in reverse vaccinology. Through database access to the DNA and protein sequences of Schistosoma mansoni and the use of bioinformatics programs, fourteen epitopes were identified. Five epitopes were obtained from proteins whose immunogenic potential had already been assessed in other studies (KP), and nine whose immunogenic potential is unknown (UP). To improve stimulation of the host immune system, the selected epitopes were modeled with a sugar moiety. After this addition, all of the epitopes showed structures similar to those observed in the native proteins, but only eleven of the peptides presented thermodynamically stable structures. Prediction analysis and molecular modeling showed that the glycopeptides presented here are important targets in the search for a vaccine against schistosomiasis. Additionally, they suggest that these molecules may be used in immunological assays to evaluate the level of protection, the effect on pathology reduction and the profile of cytokines and antibodies induced by them.

Cervical uterine lesions: an epidemiological and molecular investigation in midwestern Minas Gerais, Brazil.

Cervical uterine cancer is the second most frequent form of cancer in the female population and the fourth cause of cancer deaths among Brazilian women. In Divinópolis county, Minas Gerais state, cervical cancer accounted for 6.6% of deaths in 2007. The purpose of this study was to conduct an epidemiological and molecular investigation of samples of pre-neoplastic and neoplastic cervical uterine lesions from patients assisted at public healthcare services in the county. The study was based on clinical-epidemiological descriptions retrieved from cytological examination request forms from 2006 to 2010. For molecular analysis, samples from 95 patients were collected and DNA was extracted using the Chelex 100 method. PCR was performed for detection and typing of HPV 6/11, 16, 18, 31, and 33. Of the 52 168 patients who underwent cytological examination, 625 had pre-neoplastic or neoplastic lesions during the study period. Age distribution was consistent with the literature, with a predominance of patients aged 20-49 years. The microorganism found most frequently was Lactobacillus sp. (65%). Prominent among cellular alterations were cervical intraepithelial neoplasia I (39.7%) and atypical squamous cells of undetermined significance (32%). Molecular analysis revealed 72.6% of positive samples for HPV. HPV 16 (26.3%) was the most frequent type, followed by types 6/11 (7.4%), 18 (5.3%), 33 (2.1%), and 31 (1%). The results provided improved understanding of the association between HPV and cancer in Divinópolis, in addition to providing data that can contribute to the design of measures to prevent and control HPV infection in the county investigated.

Allele distribution of six STR/miniSTR loci (CD4, FABP2, D12S391, D14S1434, D22S1045 and D10S1248) for forensic purposes in Southeastern Brazil.

BACKGROUND: Allele frequencies for six STR/miniSTR loci were determined in a sample of unrelated individuals from Southeastern Brazil. METHODS AND RESULTS: No significant deviations from Hardy-Weinberg equilibrium proportions were observed for the loci investigated (p-values ≥ 0.2320). Statistical parameters of forensic interest such as heterozygosity (H), power of discrimination (PD) and power of exclusion (PE) were estimated. Except for marker FABP2, all STR/miniSTRs tested showed observed heterozygosities over 0.66.Combined power of discrimination and power of exclusion were 0.9999993 and 0.9925, respectively. CONCLUSIONS: Due to their ease of analysis and high informativity, these new STR multiplexes will be useful for extending current marker sets for forensic and paternity purposes.