Duration of post-vaccination immunity to yellow fever in volunteers ten years after a dose-response study - A complementary study.

A single dose of standard yellow fever (YF) vaccine is considered to provide life-long protection. In this study, we evaluate the seropositivity conferred by lower doses 10 years post-vaccination. In 2009, Bio-Manguinhos/Fiocruz performed a dose-response study with the 17DD yellow fever vaccine, administering the vaccine in the usual mean dose of 27.476 IU and in decreasing doses (10.447 IU, 3.013 IU, 587 IU, 158 IU and 31 IU), with the usual volume and route (0,5 ml subcutaneous). The decreasing doses were obtained by dilution in the laboratory of the manufacturer and the lots in test had standard quality control and were produced by good manufacturing practices (GMP). Around 30 days after the vaccination, doses down to 587 IU had similar immunogenicity and the 158 IU and 31 IU were inferior to the full dose. The seropositivity was maintained for 10 months, except on the 31 IU group. Eight years after, 85 % of 318 participants evaluated in a follow-up, maintained seropositivity that was similar across groups. Consistently, antibody titers in the reduced-dose groups were also comparable to those of the full-dose group. The current study, 10 years later, showed similarity between the vaccine groups (six arms who received the YF vaccine in decreasing doses: 27.476 IU, 10.447 IU, 3.013 IU, 587 IU, 158 IU, 31 IU) both in relation of seropositivity and in the evaluation of the geometric mean titers. The seropositivity rates across subgroups were 83,1%, 90 %, 87 %, 93 %, 83,8% and 85 %, correspondingly. These findings provides further support to the long-term immunogenicity of lower doses. Clinical trial registry: NCT04416477.

New drug candidates for osteosarcoma: Drug repurposing based on gene expression signature.

Osteosarcoma (OS) is an aggressive bone malignancy and the third most common cancer in adolescence. Since the late 1970s, OS therapy and prognosis had only modest improvements, making it appealing to explore new tools that could help ameliorate the treatment. We present a meta-analysis of the gene expression signature of primary OS, and propose small molecules that could reverse this signature. The meta-analysis was performed using GEO microarray series. We first compared gene expression from eleven primary OS against osteoblasts to obtain the differentially expressed genes (DEGs). We later filtered those DEGs by verifying which ones had a concordant direction of differential expression in a validation group of 82 OS samples versus 30 bone marrow mesenchymal stem cells (BM-MSC) samples. A final gene expression signature of 266 genes (98 up and 168 down regulated) was obtained. The L1000CDS2 engine was used for drug repurposing. The top molecules predicted to reverse the signature were afatinib (PubChem CID 10184653), BRD-K95196255 (PubChem CID 3242434), DG-041 (PubChem CID 11296282) and CA-074 Me (PubChem CID 23760717). Afatinib (Gilotrif™) is currently used for metastatic non-small-cell lung cancer with EGFR mutations, and in vitro evidence shows antineoplastic potential in OS cells. The other three molecules have reports of antineoplastic effects, but are not currently FDA-approved. Further studies are necessary to establish the potential of these drugs in OS treatment. We believe our results can be an important contribution for the investigation of new therapeutic genetic targets and for selecting new drugs to be tested for OS.

TP53 and CDKN1A mutation analysis in families with Li-Fraumeni and Li-Fraumeni like syndromes.

Li-Fraumeni and Li-Fraumeni like syndromes (LFS/LFL) represent rare cancer-prone conditions associated mostly with sarcomas, breast cancer, brain tumors, and adrenocortical carcinomas. TP53 germline mutations are present in up to 80 % of families with classic Li-Fraumeni syndrome, and in 20-60 % of families with Li-Fraumeni like phenotypes. The frequency of LFS/LFL families with no TP53 mutations detected suggests the involvement of other genes in the syndrome. In this study, we searched for mutations in TP53 in 39 probands from families with criteria for LFS/LFL. We also searched for mutations in the gene encoding the main mediator of p53 in cell cycle arrest, CDKN1A/p21, in all patients with no mutations in TP53. Eight probands carried germline disease-causing mutations in TP53: six missense mutations and two partial gene deletions. No mutations in CDKN1A coding region were detected. TP53 partial deletions in our cohort represented 25 % (2/8) of the mutations found, a much higher frequency than usually reported, emphasizing the need to search for TP53 rearrangements in patients with LFS/LFL phenotypes. Two benign tumors were detected in two TP53 mutation carriers: an adrenocortical adenoma and a neurofibroma, which raises a question about the possible implication of TP53 mutations on the development of such lesions.

Evaluation of the tshr gene reveals polymorphisms associated with typical symptoms in primary congenital hypothyroidism.

Primary congenital hypothyroidism (PCH) has an incidence of approximately 1 in each 3000-4000 live births. In the last two decades, nearly 50 types of the distinct inactivating mutations have already been described in the coding region of the tshr gene. The aim of present study was to investigate tshr gene mutations in patients with primary congenital hypothyroidism, analyzing a sample of 106 patients that were diagnosed with PCH. Genomic DNA was isolated from peripheral blood samples, and 10 exons from the TSH receptor were automatically sequenced. Five nucleotide alterations (P52T, N187N, A459A, L645L, and D727E. N187N and D727E polymorphisms) were associated with positive medical history. In view of the clinical, biochemical and molecular heterogeneity of the etiology of the PCH, the study of polymorphisms is critical for investigating the possible associations with prevailing symptoms of this disorder.

CARACTERIZAÇÃO MOLECULAR DE PACIENTES COM SUSPEITA CLÍNICA DE SÍNDROME DE LI-FRAUMENI E LI-FRAUMENI LIKE / [MOLECULAR CHARACTERIZATION OF PATIENTS WITH SUSPICIOUS CLINICAL SYNDROME OF LI-FRAUMENI AND LI-FRAUMENI LIKE]

A síndrome de Li-Fraumeni (SLF) e sua variante, Li-Fraumeni like (LFL), compõem uma condição clinicamente heterogênea de predisposição a cânceres diversos em idade precoce. O único gene conclusivamente associado à SLF/LFL é o supressor tumoral TP53. O estudo da SLF/LFL é importante por diversas razões: (1) o elevado risco de desenvolvimento de câncer em portadores de mutação em TP53 torna essencial que esses indivíduos sejam identificados e recebam aconselhamento genético; (2) a epidemiologia da SLF/LFL no mundo ainda não está determinada, o que é importante para o desenvolvimento de estratégias de manejo dos pacientes, especialmente no caso do Brasil, onde uma mutação fundadora em TP53, a R337H, mostra-se muito frequente em alguns Estados; (3) a SLF/LFL é um modelo para estudo da predisposição genética ao câncer, visto que sua heterogeneidade suscita dúvidas, como quais fatores modificam a penetrância da síndrome, e quais outros genes podem estar associados a ela nos pacientes que não apresentam mutação em TP53. A finalidade deste estudo foi realizar a caracterização fenotípica e molecular de pacientes com suspeita clínica da SLF/LFL, além de investigar a frequência da mutação fundadora R337H em diferentes coortes de pacientes oncológicos. Cinquenta e oito pacientes com suspeita clínica da SLF/LFL foram investigados quanto à presença de mutações em TP53 por sequenciamento direto e MLPA. O gene CDKN1A, mediador de TP53 na regulação do ciclo celular, também foi investigado por sequenciamento direto. Adicionalmente, três coortes de pacientes acompanhados pelo aconselhamento genético do INCA foram investigadas quanto à presença da mutação R337H de TP53: 46 pacientes com tumor de Wilms, 81 pacientes com retinoblastoma e 126 pacientes com suspeita clínica de câncer de mama e ovário hereditários...

Li-Fraumeni syndrome (LFS) and its variant, Li-Fraumeni like (LFL), comprise a clinically heterogeneous condition of predisposition to various cancers at an early age. The only conclusively gene associated to LFS/LFL is the tumor suppressor TP53. The study of LFS/LFL is important for several reasons: (1) the high risk of cancer development in patients with TP53 mutation makes it essential that these individuals be identified and receive genetic counseling; (2) the worldwide epidemiology of LFS/LFL is not yet determined, which is important for the development of management strategies for patients, especially in the case of Brazil, where a founder mutation in TP53, the R337H mutation, has shown to be very frequent in some States; (3) LFS/LFL is a model for the study of genetic predisposition to cancer, since its heterogeneity raises questions such as what factors modify the penetrance of the syndrome, and what other genes may be associated with it in patients without mutations in TP53. The purpose of this study was to perform the phenotypic and molecular characterization of patients with clinical suspicion of LFS/LFL, and to investigate the frequency of the R337H founder mutation in different cohorts of cancer patients. Fifty-eight patients with clinical suspicion of LFS/LFL were investigated for the presence of mutations in TP53 by direct sequencing and MLPA. The CDKN1A gene, TP53 mediator in cell cycle regulation, was also investigated by direct sequencing...

Segmental uniparental isodisomy of chromosome 6 causing transient diabetes mellitus and merosin-deficient congenital muscular dystrophy.

Segmental uniparental isodisomy (iUPD) is a rare genetic event that may cause aberrant expression of imprinted genes, and reduction to homozygosity of a recessive mutation. Transient neonatal diabetes mellitus (TNDM) is typically caused by imprinting aberrations in chromosome 6q24 TNDM differentially-methylated region (DMR). Approximately, 15.12 Mb upstream in 6q22-q23 is located LAMA2, the gene responsible of merosin-deficient congenital muscular dystrophy type 1A (MDC1A). We investigated a patient diagnosed both with TNDM and MDC1A, born from a twin dichorionic discordant pregnancy. Parents are first-degree cousins. Methylation sensitive-PCR of the imprinted 6q24 TNDM CpG island showed only the non-methylated (paternal) allele. Microsatellite markers and SNP array profiling disclosed normal biparental inheritance at 6p and a segmental paternal iUPD, between 6q22.33 and 6q27. Sequencing of LAMA2 exons showed a homozygous frameshift mutation, c.7490_7493dupAAGA, which predicts p.Asp2498GlufsX4, in exon 54. Her father, but not her mother, was a carrier of the mutation. While segmental paternal iUPD6 causing TNDM was reported twice, there are no previous reports of MDC1A caused by this event. This is a child with two genetic disorders, yet neither is caused by the parental consanguinity, which reinforces the importance of considering different etiological mechanisms in the genetic clinic.

WT1, WTX and CTNNB1 mutation analysis in 43 patients with sporadic Wilms' tumor.

Wilms' tumor (WT) is a heterogeneous neoplasia characterized by a number of genetic abnormalities, involving tumor suppressor genes, oncogenes and genes related to the Wnt signaling pathway. Somatic biallelic inactivation of WT1 is observed in 5-10% of sporadic WT. Somatic mutations in exon 3 of CTNNB1, which encodes ß-catenin, were initially observed in 15% of WT. WTX encodes a protein that negatively regulates the Wnt/ß-catenin signaling pathway and mediates the binding of WT1. In this study, we screened germline and somatic mutations in selected regions of WT1, WTX and CTNNB1 in 43 WT patients. Mutation analysis of WT1 identified two single-nucleotide polymorphisms, one recurrent nonsense mutation (p.R458X) in a patient with proteinuria but without genitourinary findings of Denys-Drash syndrome (DDS) and one novel missense mutation, p.C428Y, in a patient with Denys-Drash syndrome phenotype. WT1 SNP rs16754A>G (R369R) was observed in 17/43 patients, and was not associated with significant difference in age at diagnosis distribution, or with 60-month overall survival rate. WTX mutation analysis identified five sequence variations, two synonymous substitutions (p.Q1019Q and p.D379D), a non-synonymous mutation (p.F159L), one frameshift mutation (p.157X) and a novel missense mutation, p.R560W. Two sequence variations in CTNNB1 were identified, p.T41A and p.S45C. Overall survival of bilateral cases was significantly lower (p=0.005). No difference was observed when survival was analyzed among patients with WT1 or with WTX mutations. On the other hand, the survival of two patients with the CTNNB1 p.T41A mutation was significantly lower (p=0.000517) than the average.