Unique synapomorphies and high diversity in South American Raji-related Epstein-Barr virus genomes

BACKGROUND Epstein-Barr virus (EBV) is a human gammaherpesvirus etiologically linked to several benign and malignant diseases. EBV-associated malignancies exhibit an unusual global distribution that might be partly attributed to virus and host genetic backgrounds. OBJECTIVES To assemble a new genome of EBV (CEMO3) from a paediatric Burkitt's lymphoma from Rio de Janeiro State (Southeast Brazil). In addition, to perform global phylogenetic analysis using complete EBV genomes, including CEMO3, and investigate the genetic relationship of some South American (SA) genomes through EBV subgenomic targets. METHODS CEMO3 was sequenced through next generation sequencing and its coverage and gaps were corrected through the Sanger method. CEMO3 and 67 EBV genomes representing diverse geographic regions were evaluated through maximum likelihood phylogenetic analysis. Further, the polymorphism of subgenomic regions of some SA EBV genomes were assessed. FINDINGS The whole bulk tumour sequencing yielded 23,217 reads related to EBV, which 172,713 base pairs of the newly EBV genome CEMO3 was assembled. The CEMO3 and most SA EBV genomes clustered within the SA subclade closely related to the African Raji strain, forming the South American/Raji clade. Notably, these Raji-related genomes exhibit significant genetic diversity, characterised by distinctive synapomorphies at some gene levels absent in the original Raji strain. CONCLUSION The CEMO3 represents a new South American EBV genome assembled. Albeit the majority of EBV genomes from SA are Raji-related, it harbours a high diversity different from the original Raji strain.

Molecular aspects of Chikungunya virus infections in cancer patients

BACKGROUND Chikungunya virus (CHIKV) is an arbovirus that can cause chronic and debilitating manifestations. The first autochthonous case in Rio de Janeiro state was diagnosed in 2015, and an outbreak was declared in 2016. OBJECTIVE The aim of this work was to evaluate CHIKV viral load in serum, plasma and urine in cancer patients to determine the best sample for diagnosis, as well as perform molecular characterisation and phylogenetic analysis of circulating strains. METHODS Paired serum, plasma and urine collected from 31 cancer patients were tested by real-time quantitative polymerase chain reaction (qPCR) and a segment of the CHIKV E1 gene was sequenced. FINDINGS We detected 11 CHIKV+ oncological patients. Paired samples analyses of nine patients showed a different pattern of detection. Also, a higher viral load in plasma (6.84 log10) and serum (6.07 log10) vs urine (3.76 log10) was found. Phylogenetic analysis and molecular characterisation revealed East/Central/Southern Africa (ECSA) genotype circulation and three amino acids substitutions (E1-K211T, E1-M269V, E1-T288I) in positive patients. MAIN CONCLUSION The results indicate the bioequivalence of serum and plasma for CHIKV diagnosis, with urine being an important complement. ECSA genotype was circulating among patients in the period of the 2016 outbreak with K211T, M269V and T288I substitution.

Tumor-infiltrating Lymphocytes are Independent Favorable Prognostic Indicator in 17-year Disease-Free Survival in Lymph Node-Negative Triple-Negative Breast Cancer Patient.

Aims: To estimate the prognostic value of tumor-infiltrating lymphocytes, among other variables, in triple-negative breast cancer patients with a 17-year disease-free survival. Study Design: A retrospective study of 79 patients was conducted to investigate treatment, and clinical, microscopic and immunohistochemical tumor characteristics. Place and Duration of Study: Pathology Division, National Cancer Institute (INCA), Rio de Janeiro, RJ, Brazil, between January 1992 and December 1996. Methodology: Histologically diagnosed 79 node-negative triple-negative breast cancer patients underwent partial or total mastectomy with axillary lymphadenectomy, with or without radiotherapy, chemotherapy and/or hormone therapy. Disease-free survival was estimate by the Kaplan-Meier method and log-rank test. Prognostic variables were obtained by Cox regression models. Results: The 17-year disease-free survival was 50.6%. Disease-free survival was worse in patients aged 51-82 years, who underwent neoadjuvant chemotherapy and had skin compromise, geographic necrosis, grade 3 tumors, had no tumor-infiltrating lymphocytes, had vascular/lymphatic invasion, CD44+/CD24-/low and elevated Ki-67. The risk of recurrence and/or metastasis, adjusted for the remaining variables of the final Cox model was 2.44 times higher for patients aged 51-82 years, 2.60 times higher for patients undergoing neoadjuvant chemotherapy, 3.97 times higher for grade 3 tumors and 0.34 times for patients with tumor-infiltrating lymphocytes. Conclusion: The risk of recurrence and/or metastasis, adjusted for the remaining variables of the model, was about 2.5 times higher for older patients undergoing neoadjuvant chemotherapy. In grade 3 tumor patients, the risk increased almost fourfold. Patients with tumor-infiltrating lymphocytes had a 66% lower risk, i.e, tumor-infiltrating lymphocytes were shown to be a protective factor.

Spatiotemporal transcription of the P element and the 412 retrotransposon during embryogenesis of Drosophila melanogaster and D. willistoni

Transposable elements (TEs) are mobile nucleotide sequences which, through changing position in host genomes, partake in important evolutionary processes. The expression patterns of two TEs, P element transposon and 412 retrotransposon, were investigated during Drosophila melanogaster and D. willistoni embryogenesis, by means of embryo hybridization using riboprobes. Spatiotemporal transcription patterns for both TEs were similar to those of developmental genes. Although the two species shared the same P element transcription pattern, this was not so with 412 retrotransposon. These findings suggest that the regulatory sequences involved in the initial development of Drosophila spp are located in the transposable element sequences, and differences, such as in this case of the 412 retrotransposon, lead to losses or changes in their transcription patterns.

Detection of P element transcripts in embryos of Drosophila melanogaster and D. willistoni

The P element is one of the most thoroughly studied transposable elements (TE). Its mobilization causes the hybrid dysgenesis that was first described in Drosophila melanogaster. While studies of the P element have mainly been done in D. melanogaster, it is believed that Drosophila willistoni was the original host species of this TE and that P was transposed to the D. melanogaster genome by horizontal transfer. Our study sought to compare the transcriptional behavior of the P element in embryos of D. melanogaster, which is a recent host, with embryos of two strains of D. willistoni, a species that has contained the P element for a longer time. In both species, potential transcripts of transposase, the enzyme responsible for the TE mobilization, were detected, as were transcripts of the 66-kDa repressor, truncated and antisense sequences, which can have the ability to prevent TEs mobilization. The truncated transcripts reveal the truncated P elements present in the genome strains and whose number seems to be related to the invasion time of the genome by the TE. No qualitative differences in antisense transcripts were observed among the strains, even in the D. willistoni strain with the highest frequency of heterochromatic P elements.

O elemento P é um dos elementos transponíveis (TE) mais amplamente estudado. Sua mobilização causa a disgenesia do híbrido que foi primeiramente descrita em D. melanogaster. Apesar dos estudos sobre o elemento P terem sido realizados principalmente com D. melanogaster, acredita-se que D. willistoni foi a espécie hospedeira original deste TE e que ele se transpôs para o genoma de D. melanogaster por transferência horizontal. Nosso estudo visou a comparação do comportamento transcripcional do elemento P em embriões de D. melanogaster, que é a hospedeira recente, com o de embriões de duas linhagens de D. willistoni, uma espécie que é, a longo tempo, hospedeira do elemento P. Em ambas as espécies foram detectados transcritos potenciais da transposase, enzima responsável pela mobilização do TE, bem como transcritos do repressor de 66-kDa e de seqüências truncadas e antisenso, os quais podem ter a habilidade de prevenir a mobilização de TEs. Os transcritos truncados refletem os elementos P truncados presentes no genoma das linhagens e cujo número parece relacionado com o tempo de invasão do genoma pelo TE. Nenhuma diferença qualitativa de transcritos antisenso foi observada entre as espécies, mesmo na linhagem de D. willistoni com alta freqüência de elemento P heterocromático.

Células-tronco de origem hematopoéticas: expansão e perspectivas de uso terapêutico / Hematopoietic stem cells: expansion and perspectives for therapeutic use

A célula-tronco hematopoética (CTH) tem um enorme potencial para reconstituir o sistema hematopoético, o que permitiu o desenvolvimento de estratégias de terapias celulares para doenças neoplásicas ou não. Em paralelo com os avanços clínicos, estudos sobre os mecanismos moleculares que levam as células-tronco hematopoéticas a decidir pela autorrenovação, diferenciação ou apoptose têm contribuído para o conhecimento de como controlar a cinética da CTH. Esta revisão tenta descrever como estes novos avanços podem ser utilizados no desenvolvimento de estratégias de expansão das CTHs para uso terapêutico.

Hematopoietic stem cells (HSCs) have the potential for reconstituting the hematopoietic system a characteristic that has enabled the development of cell based therapies for neoplastic and non-malignant diseases. In parallel with these clinical advances, elucidation of molecular mechanisms controlling self-renewal, differentiation or apoptosis have contributed to our understanding of the molecular events that control HSC kinetics. This review focuses on how these advances can be translated in new strategies for HSC expansion and their use in therapies.

The impact of addictional chromosomal abnormalities in response to imatinib mesylate therapy for chronic myeloid leukemia

Imatinib induces a complete cytogenetic response in more than 80% of newly diagnosed patients with chronicmyeloid leukemia (CML) in the chronic phase (CP) and in 41% of patients in the first chronic phase after failureof interferon- treatment. However, some patients do not respond completely. Therefore, according to moststudies, drug resistance in CML patients treated with imatinib is correlated with cytogenetic abnormalities acquiredduring treatment. In this study we analyzed 48 CML patients treated with imatinib mesylate after interferon- resistance in order to elucidate the impact of additional chromosomal abnormalities prior to imatinib in response to therapy. Cytogenetic abnormalities in addition to the Philadelphia chromosome (Ph) were detected in 33.3% of patients. Patients with Ph as the sole cytogenetic abnormality prior to imatinib therapy presented a major cytogeneticresponse and significantly longer median overall survival (p=0.006) than patients with additional chromosomalabnormalities. Therefore, in this group of patients, another choice of treatment should be considered, such as stemcell transplantation or combination regimens as appropriate. The present study indicates the importance of detecting a double Ph chromosome prior to imatinib therapy. Patients showing this abnormality did not respond to imatinib, thus indicating the abnormality's association with resistance. Our study suggests that classical cytogenetic analysisis still an important tool prior to and during follow-up of CML patients treated with imatinib.

Imatinibe induz à resposta citogenética completa em cerca de 80 por cento dos pacientes diagnosticados com leucemia mielóide crônica (LMC) em fase crônica (FC), e em 41 por cento dos pacientes em primeira FC após falha do tratamento com interferon-alfa. Alguns pacientes, entretanto, não respondem completamente. Em muitos estudos, a resistência à droga em pacientes tratados com imatinibe é correlacionada a alterações cromossômicas adquiridas durante o tratamento. No presente estudo, foram analisados 48 pacientes tratados com imatinibe após resistência ao interferon-alfa, com o objetivo de verificar o impacto das alterações cromossômicas adicionais ao Philadelphia (Ph), prévias à terapia com imatinibe. Alterações adicionais foram detectadas em 33,3 por cento dos pacientes. Pacientes com somente o cromossomo Ph apresentaram melhor taxa de resposta citogenética e sobrevida global significativa maior quando comparados com os pacientes que apresentavam alterações cromossômicas adicionais antes do início da terapia com imatinibe. Assim, nesse grupo de pacientes, a escolha de outra conduta terapêutica, como o transplante de células tronco-hematopoéticas ou regime de combinação de drogas, pode ser indicada. O presente estudo indica a importância do duplo Ph antesdo início da terapia com imatinibe. Todos os pacientes com esta alteração não responderam ao tratamento, sendo a mesma associada à resistência à droga. Este estudo sugere que a citogenética clássica permanece como uma ferramenta importante no monitoramento de pacientes portadores de LMC tratados com imatinibe.

Karyotype abnormalities and their clinical significance in a group of chronic myeloid leukemia patients treated with hematopoietic stem cell transplantation

CONTEXT AND OBJECTIVE: Following hematopoietic stem cell transplantation (HSCT), karyotyping is a valuable tool for monitoring engraftment and disease status. Few studies have examined the prognostic significance of karyotypes in patients who underwent HSCT for chronic myeloid leukemia (CML). The objective of this study was to evaluate the significance of pretransplantation cytogenetic status in relation to outcomes following HSCT in CML patients. DESIGN AND SETTING: Case series study at Instituto Nacional do Câncer (INCA), Rio de Janeiro, Brazil. METHODS: Cytogenetic analysis was performed by G banding on 39 patients treated with HSCT. RESULTS: Thirty-one patients were in the chronic phase and eight were in the accelerated phase. Prior to HSCT, additional chromosomal abnormalities on the Philadelphia (Ph) chromosome were found in 11 patients. The most frequent additional abnormality was a double Ph, which was observed in four cases. Following HSCT, full chimeras were observed in 31 patients (79.5 percent). Among these, 23 (82.3 percent) had presented Ph as the sole abnormality. Mixed chimeras were observed in seven patients, of which three had additional abnormalities. Only one case did not present any cytogenetic response. Five patients presented cytogenetic relapse associated with clinical relapse following HSCT. Twenty-seven patients are still alive and present complete hematological and cytogenetic remission. CONCLUSION: In our study, the presence of additional abnormalities was not associated with worse outcome and relapse risk. Also, no differences in survival rates were observed. Our study supports the view that classical cytogenetic analysis remains an important tool regarding HSCT outcome.

RESUMO CONTEXTO E OBJETIVO: Após o transplante de células tronco-hematopoéticas (TCTH), o cariótipo é uma ferramenta valiosa para monitorar o status do enxerto e da doença. Poucos estudos investigaram o significado prognóstico do cariótipo nos pacientes que se submeteram ao TCTH para leucemia mielóide crônica (LMC). O objetivo desse estudo foi verificar o significado dos achados citogenéticos pré-TCTH em pacientes portadores de LMC. TIPO DE ESTUDO E LOCAL: Série de casos. Instituto Nacional do Câncer (INCA), Rio de Janeiro, Brasil. METODOLOGIA: Foram realizados estudos citogenéticos por bandeamento G em 39 pacientes submetidos ao TCTH. RESULTADOS: Trinta e um pacientes estavam em fase crônica e oito em fase acelerada. Pré-TCTH, alterações cromossômicas adicionais ao cromossomo Philadelphia (Ph) foram observadas em 11 pacientes. A mais freqüente foi o duplo Ph observado em quatro casos. Após o TCTH, quimerismo total foi observado em 31 pacientes (79,5 por cento). Desses, 23 (82,3 por cento) apresentavam somente o cromossomo Ph. Quimerismo misto foi observado em sete pacientes, sendo três com alterações adicionais ao Ph. Um caso não apresentou resposta ao TCTH. Recaída citogenética associada com recaída clínica foi observada em cinco pacientes. Após o TCTH, 27 pacientes permanecem vivos e com remissão clínica e citogenética. CONCLUSÃO: Em nosso estudo a presença de alterações cromossômicas adicionais ao Ph, prévias ao TCTH, não foi associada com pior evolução, com risco de recaída, bem como não foi observada diferença entre as taxas de sobrevida. Nosso estudo sugere que a citogenética clássica permanece uma grande ferramenta no monitoramento do TCTH.

Connexins in the early development of the African clawed frog Xenopus laevis (Amphibia): The role of the connexin43 carboxyl terminal tail in the establishment of the dorso-ventral axis

Connexins are a family of related proteins identified in vertebrate forming gap junctions, which mediate cell-to-cell communication in early embryos, with an important role in establishing embryonic asymmetry and æcommunication compartments. By in situ hybridization, immunocytochemistry, reverse transcriptase PCR (RT-PCR) and western blotting we show that a Cx43-like molecule is present in oocytes and embryos of the African clawed frog Xenopus laevis, with specific localization in the animal-vegetal axis. This specific distribution is suggestive for an important role for this protein in the establishment of the dorso-ventral axis. Antisense RNA and antibodies directed against rat carboxyl terminal tail of the Cx43 (CT-Cx43) and injected in 1-cell stage Xenopus embryos, induced pronounced alterations in nervous system development, with a severe ventralization phenotype. Coherently, the overexpression of CT-Cx43 produced a dorsalization of the embryos. In antisense treated embryos, the expression of the beta-catenin gene is eliminated from the Nieuwkoop center, the pattern expression of the Chordin, Xnot and Xbra is modified, with no effect in expression of the Goosecoid gene. In CT-Cx43 mRNA treated embryos the pattern of expression of the beta-catenin, Chordin, Goosecoid, Xnot and engrailed-2 genes is modified. The expression of beta-catenin is increased in the Nieuwkoop center, the expression pattern of Chordin and Goosecoid is expanded to the posterior neural plate and engrailed-2 presents ectopic expression in the ventral region. Taken together our data suggest a role for CT-Cx43 as a maternal determinant with a critical function in the formation of the dorso-ventral axis in Xenopus laevis. The Cx43 may be one of the earliest markers of the dorso-ventral axis in these embryos and could possibly be acting through regionalization of factors responsible for the establishment of this axis.

Uma nova técnica para avaliar a lesão endotelial na arteriosclerose / A new technique to evaluate the endotelium lesion in atheroesclerosis

Os autores propõem uma nova técnica para avaliar a relação entre infecção e aterosclerose pela coleta de sangue da artéria coronária depois da lesão ou do seio coronariano em casos de insuficiência coronariana aguda durante a angioplastia, buscando bactérias, vírus e fragmentos de DNA virais

Possible role of Msx1 in murine hematopoiesis

The Msx1 gene is expressed at sites of epitelium-mesenchymal interaction throughout development and is important in morphogenesis since Msx1 null mice die 24 h. after birth and show defects in craniofacial bones. The Msx1 gene code for a transcription factor activated by BMP4 and, when active, maintains progenitor cells in an undifferentiated state. BMP4 is a crucial factor for hematopoietic development in the murine embryo and although Msx1 is activated by BMP4, there have been no reports relating Msx1 to hematopoiesis. To investigate the role of Msx1 in murine hematopoiesis, samples of hematopoietic tissues (spleen, liver, thymus, bone marrow) and blood collected from 18.5 days post coitum (dpc) fetuses of Msx1 mutant and wild-type embryos were analyzed histologically. Blood cell counts as well as erythropoietic clonogenic assays for liver and bone marrow cells were also done. Histological analysis of the spleen suggested the presence of fewer erythrocytes but more hematopoietic progenitors in mutant embryos. While the bone marrow of wild-type mice had mesenchymal and hematopoietic components, in mutant mice only the hematopoietic component was seen. Hematopoietic progenitors and more mature cells, as well as extracellular matrix, filled the entire bone marrow in heterozygous mutants. In homozygous null mice, this phenotype was enhanced with a poor bone marrow. In hematopoietic colony assays, the liver and bone marrow of Msx1 knockout embryos had a higher number of erythropoietic progenitors whereas peripheral blood had a lower number of erythrocytes compared to wild-type mice. These results suggest that Msx1 plays a role in erythropoietic differentiation since low or null gene expression increased the level of progenitors and decreased the number of differentiated erythroid cells. Msx1 appears to act in mesenchymal cells since in Msx1-/-embryos the hematopoietic cells were abnormal and the cells that supported hematopoietic development in bone marrow were missing.

Differential expression of notch signaling-related transcripts accompanies Pro-thymocyte proliferation and phenotype transition induced by epidermal growth factor plus insulin in fetal thymus organ cultures

Thymus regression upon stressing stimuli, such as infectious diseases, is followed by organ reconstitution, paralleling its development in ontogeny. A narrow window of thymus development was here studied, encompassing the pro-T lymphoid precursor expansion during specification stages, by the use of epidermal growth factor plus insulin (INS) in murine fetal thymus organ cultures. Aiming to disclose signaling pathways related to these stages, cultured thymus lobes had their RNA extracted, for the search of transcripts differentially expressed using RNAse protection assays and reverse transcriptase-polymerase chain reactions. We found no difference that could explain INS-driven thymocyte growth, in the pattern of transcripts for death/proliferation mediators, or for a series of growth factor receptors and transcriptional regulators known as essential for thymus development. Thymocyte suspensions from cultured lobes, stained for phenotype analysis by fluorescence activated cell sorting, showed a decreased staining for Notch1 protein at cell surfaces upon INS addition. We analyzed the expression of Notch-related elements, and observed the recruitment of a specific set of transcripts simultaneous and compatible with INS-driven thymocyte growth, namely, transcripts for Notch3, for its ligand Jagged2, and for Deltex1, a mediator of a poorly characterized alternative pathway downstream of the Notch receptor.

Análise dos transcritos da translocaçäo t(9; 22) / An analysis of transcriptions of the translocation t(9, 22) in chronic myeloid leukemia

A leucemia mielóide crônica é uma doença proliferativa do sistema hematopoiético, caracterizada pela expansäo clonal de uma célula tronco primitiva e pluripotente denominada ®stem cell¼, que tem a capacidade de se diferenciar em células mielóides, monocíticas , megacariocíticas e células B e T. Em homeostase, existe um equilíbrio entre proliferaçäo, diferenciaçäo e renovaçäo das células tronco, equilíbrio este que se encontra alterado em pacientes com Leucemia mielóide crônica, devido a uma proliferaçäo e diferenciaçäo aumentada e anormal relacionada à atividade de tirosino quinase do produto do gene quimérico BCR/ABL resultante da translocaçäo t(9;22), que se apresenta como marcador de doença. Vários transcritos quiméricos têm sido descritos e acredita-se que a gravidade do quadro clínico dependa do tipo de mRNA gerado. No presente trabalho analisamos 28 amostras de 27 pacientes diagnosticados com Leucemia mielóide crônica. Todos possuíam a translocaçäo t(9;22) e foram analisados para a presença dos transcritos resultantes das fusöes b3a2 ou b2a2 por RT_PCR e Nested-PCR, técnicas que se mostraram mais sensíveis para a identificaçäo dos transcritos. Entre os pacientes, 12 por cento apresentaram fusäo b3a2, 18 por cento possuíam fusäo b2a2 e 32 por cento possuíam os dois tipos de transcritos. A presença de um dos tipos de transcritos, b3a2, parece estar relacionada com contagem de plaquetas acima de 1 milhäo/mm3, reconhecida como característica de mau prognóstico em pacientes com Leucemia mielóide crônica.

Temperature-dependent gonadal hybrid dysgenesis in Drosophila willistoni

Temperature-dependent gonadal dysgenesis was shown to occur in the progeny of both inter- and intrastrain crosses involving two populations of Drosophila willistoni, one of which was an old laboratory stock, and the other, freshly collected from a natural population. We propose that the phenomenon observed was caused by the mobilization of transposable elements, as occurs in several other Drosophila species.

Cytogenetic study of 50 Brazilian patients with primary myelodysplastic syndrome

Neste trabalho foram estudados citogeneticamente 50 pacientes de diversas unidades hospitalares do Rio de Janeiro, Brasil, diagnosticados com síndrome mielodisplásica primária. Os dados obtidos mostraram uma freqüência de anomalias cromossômicas de 32 por cento nestes pacientes, sendo as anomalias mais encontradas a del(5q) (10 por cento), -7 (6 por cento) e +8 (quatro por cento). Pacientes com anemia refratária ou anemia refratária com sideroblastos em anel apresentaram cariótipos normais ou com deleçöes simples como del(5q) ou -Y, enquanto pacientes com anemia refratária com excesso de blastos, anemia refratária com excesso de blastos em transformaçäo e leucemia mielomonocítica crônica apresentaram cariótipos complexos ou com anomalias simples do tipo monossomia do 7 ou trissomia do 8, tendo um alto índice de evoluçäo para leucemia mielóide aguda.