Resumo em Inglês:

Abstract Antibody-drug conjugates (ADC), precisely deliver a cytotoxic agent to antigen-expressing tumor cells by using specific binding strategies of antibodies. The ADC has shown the ability of potent bio-therapeutics development but indefinite stoichiometric linkage and full-length antibody penetration compromised the field of its advancement. Single chain variable fragments convention instead of the full-length antibody may overcome the challenge of rapid penetration and internalization. Programmed cell death ligand-1 interaction with PD-1 has recently revolutionized the field of immunotherapy. We systematically designed scPDL1-DM1 drug conjugate by linking scFv-PD-L1 proteins (scFv) with maytansinoids (DM1) cytotoxic agent through succinimidyl trans-4-maleimidylmethyl cyclohexane-1- carboxylate (SMCC) linker. Binding affinity was confirmed by immunocytochemistry, spectrophotometry and gel electrophoresis analysis. The scPDL1-DM1 showed specific binding with PD-L1 positive tumor cells and retained in vitro anti-cell proliferation activity. The intracellular trafficking of the drug was evaluated in A549 cancer cell lines, and maximum trafficking was observed after two hours of incubation. The generated drug can be utilized as a potent tool for site-specific conjugation, predicting specificity in vitro activities with extended range against PD-L1 positive cancer cells and can be utilized for further in vivo testing and clinical therapeutics development.

Resumo em Inglês:

Abstract Laron’s syndrome (LS) is a rare genetic disorder characterized by insensitivity to growth hormone (GH). Up to the present time, over 70 mutations of GH receptor (GHR) gene have been identified leading to GH/insulin-like growth factor type 1 (IGF1) signaling pathway defect. The number of LS patients worldwide is unknown, as many are probably undiagnosed. We report two sibs from a consanguineous family from Minas Gerais, southeastern Brazil. The parents have three children. The older, a 4-years-old girl was 80.2 cm tall (-5.7 SDS height/age), and the youngest sister, aged 3 years, was 73.2 cm tall (-5.82 SDS height/age). Their clinical and biochemical features are typical of LS patients, such as high serum level of GH and low IGF1 concentrations. A homozygous c.1A>T nucleotide substitution in GHR exon 2 in the probands’ samples was identified. Their parents and healthy sister are heterozygous for the same variant that abolishes the translation initiation codon of GHR. This mutation has not been reported in Brazilian patients and was previously associated with an LS phenotype in a single 29-year-old Spanish man. In addition to this case report, we summarize the main characteristics and molecular data of the 21 LS Brazilian patients who have been published to date.

Resumo em Inglês:

Abstract MicroRNAs (miRNAs) play an essential role in gene expression and affect the development of tumours, including breast cancer (BC). Polymorphisms in miRNA genes can affect the interaction of miRNAs with their target messenger RNA by interfering, creating or disrupting target sites. The single nucleotide polymorphism (SNP) rs2910164, located in the seed region of miR146a, was shown to be associated with BC among different populations. In the present study, we investigated whether rs2910164 is associated with BC in 326 patients and 411 controls from a Brazilian population of predominantly European ancestry. The presence of the allele rs2910164*C was associated with an increased risk of BC (OR=1.4, 95% CI=1.03-1.85, p = 0.03). We also analysed publicly available RNA-seq data to evaluate if miR146a is differentially expressed in different subtypes of BC. Genotyping was performed by polymerase chain reaction with sequence-specific primers (PCR-SSP). By leveraging public data from TCGA database, we analysed 461 patients and found that miR146a is significantly more expressed in BC than in non-tumor tissue (1.47 fold, p = 0.02) and is expressed to a greater degree in aggressive BC subtypes.

Resumo em Inglês:

Abstract Beta thalassemia (β-thal) is a frequent monogenic disease, is clinically and molecularly heterogeneous. This study described molecular and laboratory findings for three Mexican patients with β-thal intermedia phenotype and their relatives. Three Mexican families were studied for presenting β-thal intermedia, ARMS-PCR and Gap-PCR were performed to screen for common mutations, Sanger sequencing for rare or new alleles, and MLPA for identifying deletions and or duplications. In all three families we observed, in heterozygote condition, the mutation c.118C > T (p.Gln39*) also known as codon 39(C > T) in the β globin gene (HBB) associated with a novel molecular defect: a new duplication of the alpha globin gene cluster, a new deletion that includes the loss of exon 3 of HBB and finally a novel mutation in the 3’UTR of HBB (HBB: c.*132C > A). We report three Mexican families with beta thalassemia intermedia due to different molecular basis; a new single nucleotide mutation involving the last nucleotide of the β-globin chain transcript; and two possible new DNA rearrangements, an α cluster duplication, and a partial β gene deletion.

Resumo em Inglês:

Abstract We aimed to analyze the correlation between ABCG2 gene polymorphisms of 34 GG/(GA + AA) loci, 421 CC/(AC + AA) loci, and non-small cell lung cancer (NSCLC) therapeutic effects via meta-analysis. With key words, the databases PubMed and EMBASE were searched for clinical studies on ABCG2 polymorphism and NSCLC. RR and 95% CIs were used to compute combined effects, followed by heterogeneity testing. Publication bias was examined using the funnel plot method. Review Manager 5.3 software was used for the meta-analysis. Ten studies were included. No evidence of heterogeneity exists in these studies. The results indicate that two polymorphic loci of ABCG2 gene (34 G>A, and 421 C>A) had no relationship with the curative effect of chemotherapy for NSCLC, except ABCG2 34G>A, which had a significant relationship with the skin toxicity complication. There was no significant relationship between these polymorphisms and complications (skin toxicity, diarrhea, interstitial pneumonia, liver dysfunction, and neutropenia). Begg’s test and Egger’s test indicated that there was no obvious publication bias. The meta-analysis indicated that there was no significant correlation between ABCG2 gene polymorphism and NSCLC outcomes.

Resumo em Inglês:

Abstract The Florida manatee (Trichechus manatus latirostris) is an endangered subspecies of the West Indian manatee (T. manatus), which inhabits inland and marine waters of southeastern United States. In this study, we assembled the mitochondrial genome (mtDNA) of the Florida manatee from whole genome shotgun reads. As a result, we show that the currently annotated T. manatus mtDNA belongs to a different species, the Amazonian manatee (T. inunguis). The newly assembled Florida manatee mtDNA is 16,881 bp in length, with 13 protein-coding genes, two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs) and one non-coding control region (D-loop). Phylogenetic analysis based on the control region indicates the newly assembled mtDNA is haplotype A01, characteristic of T. m. latirostris, while the current mtDNA associated with the Florida manatee genome assembly has a Ti02 haplotype that is found in Amazonian manatees and hybrids.

Resumo em Inglês:

Abstract The monkey frog, Pithecopus rusticus (Anura, Phyllomedusidae) is endemic to the grasslands of the Araucarias Plateau, southern Brazil. This species is known only from a small population found at the type locality. Here, we analyzed for the first time the chromosomal organization of the repetitive sequences, including seven microsatellite repeats and telomeric sequences (TTAGGG)n in the karyotype of the species by Fluorescence in situ Hybridization. The dinucleotide motifs had a pattern of distribution clearly distinct from those of the tri- and tetranucleotides. The dinucleotide motifs are abundant and widely distributed in the chromosomes, located primarily in the subterminal regions. The tri- and tetranucleotides, by contrast, tend to be clustered, with signals being observed together in the secondary constriction of the homologs of pair 9, which are associated with the nucleolus organizer region. As expected, the (TTAGGG)n probe was hybridized in all the telomeres, with hybridization signals being detected in the interstitial regions of some chromosome pairs. We demonstrated the variation in the abundance and distribution of the different microsatellite motifs and revealed their non-random distribution in the karyotype of P. rusticus. These data contribute to understand the role of repetitive sequences in the karyotype diversification and evolution of this taxon.

Resumo em Inglês:

Abstract Interspecific hybridization is required for the development of Jatropha curcas L. improved cultivars, due to its narrow genetic basis. The present study aimed to analyze the parental genomic composition of F1 and BC1F1 generations derived from interspecific crosses (J. curcas/J. integerrima and J. curcas/J. multifida) by GISH (Genomic In Situ Hybridization), and the meiotic index and pollen viability of F1 hybrids. In F1 cells from both hybrids, 11 chromosomes of each parental was observed, as expected, but chromosome rearrangement events could be detected using rDNA chromosome markers, suggesting unbalanced cells. In the BC1F1, both hybrids had 22 chromosomes, suggesting that only n = 11 gametes were viable in the next generation. However, GISH allowed the identification of three and two alien chromosomes in J. curcas//J. integerrima and J. curcas//J. multifida BC1F1 hybrids, respectively, suggesting a preferential transmission of J. curcas chromosomes for both hybrids. Pollen viability in F1 hybrids derived from J. curcas/J. integerrima crosses were higher (82-83%) than those found for J. curcas/J. multifida (68%), showing post-meiotic problems in these last hybrids, with dyads, triads, polyads, and micronuclei as post-meiosis results. The here presented cytogenetic characterization of interspecific hybrids and their backcross progenies can contribute to the selection of the best genotypes for future assisted breeding of J. curcas.

Resumo em Inglês:

Abstract We have identified 46 RNA editing sites located in 20 chloroplast (cp) genes of Borassus flabellifer (Asian Palmyra palm), family Arecaceae, and tested these genes for supporting phylogenetic study among the commelinids. Among the 46 sites, 43 sites were found to cause amino acid alterations, which were predicted to increase the hydrophobicity and transmembrane regions of the proteins, and one site was to cause a premature stop codon. Analysis of these editing sites with data obtained from seed plants showed that a number of shared-editing sites depend on the evolutionary relationship between plants. We reconstructed a deep phylogenetic relationship among the commelinids using seven RNA edited genes that are orthologous among monocots. This tree could represent the relationship among subfamilies of Arecaceae family, but was insufficient to represent the relationship among the orders of the commelinid. After adding eight gene sequences with high parsimony-informative characters (PICs), the tree topology was improved and could support the topology for the commelinid orders ((Arecales,Dasypogenaceae) (Zingiberales+Commelinales,Poales)). The result provides support for inherent RNA editing along the evolution of seed plants, and we provide an alternative set of loci for the phylogenetic tree reconstruction of Arecaceae’s subfamilies.

Resumo em Inglês:

Abstract The ants of the genus Atta are considered important pests to agriculture in the Americas, although Atta species are also important contributors to ecosystem functions in the various habitats in which they occur. The aim of this study was to assemble four complete mitochondrial genomes of the genus Atta, construct the phylogenomic tree, and analyze the gene content, order, and organization. The mitogenomes of A. colombica, A. opaciceps, A. texana, and A. sexdens rubropilosa comprise 18,392, 19,257, 19,709, and 19,748 bp, respectively. The four Atta mitogenomes showed the charactistics typical of those of insects, with 13 protein-coding genes, 22 tRNAs, and 2 rRNAs, with genes displayed in the conventional order. Analysis for intergenic spacer regions showed that Atta intergenic spacers are larger than those of the outgroups. Phylogenomic analyses using partial cytochrome oxidase I gene sequences showed similar topologies to previous phylogenetic analyses, with high clade support values. We conclude that Atta mitogenomes are characterized by high conservation in gene order and have giant intergenic spacers in the genus Atta.

Resumo em Inglês:

Abstract Anti-androgen therapies, including orchiectomy, are effective at promoting prostate cancer remission, but are followed by progression to the more aggressive castration-resistant prostate cancer (CRPC). Castration promotes gland and tumor shrinkage. However, prostate adaptation to androgen deprivation involves striking parallel events, all requiring changes in gene expression. We hypothesized that transcription factors (TF) and other transcription-related genes are needed to orchestrate those changes. In this work, downstream analysis using bioinformatic tools and published microarray data allowed us to identify sixty transcriptional regulators (including 10 TF) and to integrate their function in physiologically relevant networks. Functional associations revealed a connection between Arnt, Bhlhe41 and Dbp circadian rhythm genes with the Ar circuitry and a small gene network centered in Pex14, which might indicate a previously unanticipated metabolic shift. We have also identified human homologs and mapped the corresponding genes to human chromosome regions commonly affected in prostate cancer, with particular attention to the PTEN/HHEX/MXI1 cluster at 10q23-25 (frequently deleted in PCa) and to MAPK1 at 22q11.21 (delete in intermediate risk but not in high risk PCa). Twenty genes were found mutated or with copy number alterations in at least five percent of three cancer cohorts and six of them (PHOX2A, NFYC, EST2, EIF2S1, SSRP1 and PARP1) associated with impacted patient survival. These changes are specific to the adaptation to the hypoandrogen environment and seem important for the progression to CRPC when mutated.

Resumo em Inglês:

Abstract In Dual RNA-Seq experiments the simultaneous extraction of RNA and analysis of gene expression data from both interacting organisms could be a challenge. One alternative is separating the reads during in silico data analysis. There are two main mapping methods used: sequential and combined. Here we present a combined approach in which the libraries were aligned to a concatenated genome to sort the reads before mapping them to the respective annotated genomes. A comparison of this method with the sequential analysis was performed. Two RNA-Seq libraries available in public databases consisting of a eukaryotic (Zea mays) and a prokaryotic (Herbaspirillum seropediceae) organisms were mixed to simulate a Dual RNA-Seq experiment. Libraries from real Dual RNA-Seq experiments were also used. The sequential analysis consistently attributed more reads to the first reference genome used in the analysis (due to cross-mapping) than the combined approach. More importantly, the combined analysis resulted in lower numbers of cross-mapped reads. Our results highlight the necessity of combining the reference genomes to sort reads previously to the counting step to avoid losing information in Dual RNA-Seq experiments. Since most studies first map the RNA-Seq libraries to the eukaryotic genome, much prokaryotic information has probably been lost.