Fumonisin-containing diets decrease the metabolic activity of myenteric neurons in rats.

Fumonisins are naturally occurring mycotoxins that contaminate food for human and animal consumption. They have neurotoxic effects, but the mechanisms by which these toxins affect the nervous system are not fully known. In the present study, male Wistar rats were fed between 21 and 63 days of age with diets that contained fumonisins B1+B2 at 0, 1, and 4 mg/kg. The following variables were assessed: food consumption, growth, body weight gain, and blood parameters. Morphoquantitave analyses of the most metabolically active myenteric neurons were performed, detected by NADH-diaphorase activity. Nitrergic neurons were detected by NADPH-diaphorase activity. The fumonisin-containing diets did not significantly alter food consumption or the body or plasma parameters. These diets decreased the metabolic activity of jejunal myenteric neurons, reducing neuronal density of the most metabolic active neurons by 30.8% and the cell body area by 4.3%. The diets also decreased the cell body area of nitrergic neurons by 22.1%. The effects of fumonisin B1 on the respiratory metabolism of isolated mitochondria in the brain and liver were also assessed. A decrease in oxygen consumption up to a 29% in the brain and 38% in the liver was observed in mitochondrial isolates to which 50 µM fumonisin B1 was added. The decrease in respiratory activity that was triggered by exposure to fumonisins was related to the lower metabolic activity of myenteric neurons, which had a negative impact on neuroplasticity of the enteric nervous system.

Aspergillus fumigatus Transcription Factors Involved in the Caspofungin Paradoxical Effect.

Aspergillus fumigatus is the leading cause of pulmonary fungal diseases. Azoles have been used for many years as the main antifungal agents to treat and prevent invasive aspergillosis. However, in the last 10 years there have been several reports of azole resistance in A. fumigatus and new strategies are needed to combat invasive aspergillosis. Caspofungin is effective against other human-pathogenic fungal species, but it is fungistatic only against A. fumigatus Resistance to caspofungin in A. fumigatus has been linked to mutations in the fksA gene that encodes the target enzyme of the drug ß-1,3-glucan synthase. However, tolerance of high caspofungin concentrations, a phenomenon known as the caspofungin paradoxical effect (CPE), is also important for subsequent adaptation and drug resistance evolution. Here, we identified and characterized the transcription factors involved in the response to CPE by screening an A. fumigatus library of 484 null transcription factors (TFs) in CPE drug concentrations. We identified 11 TFs that had reduced CPE and that encoded proteins involved in the basal modulation of the RNA polymerase II initiation sites, calcium metabolism, and cell wall remodeling. One of these TFs, FhdA, was important for mitochondrial respiratory function and iron metabolism. The ΔfhdA mutant showed decreased growth when exposed to Congo red or to high temperature. Transcriptome sequencing (RNA-seq) analysis and further experimental validation indicated that the ΔfhdA mutant showed diminished respiratory capacity, probably affecting several pathways related to the caspofungin tolerance and resistance. Our results provide the foundation to understand signaling pathways that are important for caspofungin tolerance and resistance.IMPORTANCEAspergillus fumigatus, one of the most important human-pathogenic fungal species, is able to cause aspergillosis, a heterogeneous group of diseases that presents a wide range of clinical manifestations. Invasive pulmonary aspergillosis is the most serious pathology in terms of patient outcome and treatment, with a high mortality rate ranging from 50% to 95% primarily affecting immunocompromised patients. Azoles have been used for many years as the main antifungal agents to treat and prevent invasive aspergillosis. However, there were several reports of evolution of clinical azole resistance in the last decade. Caspofungin, a noncompetitive ß-1,3-glucan synthase inhibitor, has been used against A. fumigatus, but it is fungistatic and is recommended as second-line therapy for invasive aspergillosis. More information about caspofungin tolerance and resistance is necessary in order to refine antifungal strategies that target the fungal cell wall. Here, we screened a transcription factor (TF) deletion library for TFs that can mediate caspofungin tolerance and resistance. We have identified 11 TFs that are important for caspofungin sensitivity and/or for the caspofungin paradoxical effect (CPE). These TFs encode proteins involved in the basal modulation of the RNA polymerase II initiation sites, calcium metabolism or cell wall remodeling, and mitochondrial respiratory function. The study of those genes regulated by TFs identified in this work will provide a better understanding of the signaling pathways that are important for caspofungin tolerance and resistance.

Expression of human HSP27 in yeast extends replicative lifespan and uncovers a hormetic response.

Human HSP27 is a small heat shock protein that modulates the ability of cells to respond to heat shock and oxidative stress, and also functions as a chaperone independent of ATP, participating in the proteasomal degradation of proteins. The expression of HSP27 is associated with survival in mammalian cells. In cancer cells, it confers resistance to chemotherapy; in neurons, HSP27 has a positive effect on neuronal viability in models of Alzheimer's and Parkinson's diseases. To better understand the mechanism by which HSP27 expression contributes to cell survival, we expressed human HSP27 in the budding yeast Saccharomyces cerevisiae under control of different mutant TEF promoters, that conferred nine levels of graded basal expression, and showed that replicative lifespan and proteasomal activity increase as well as the resistance to oxidative and thermal stresses. The profile of these phenotypes display a dose-response effect characteristic of hormesis, an adaptive phenomenon that is observed when cells are exposed to increasing amounts of stress or toxic substances. The hormetic response correlates with changes in expression levels of HSP27 and also with its oligomeric states when correlated to survival assays. Our results indicate that fine tuning of HSP27 concentration could be used as a strategy for cancer therapy, and also for improving neuronal survival in neurodegenerative diseases.

Pathway-focused gene expression profiles and immunohistochemistry detection identify contrasting association of caspase 3 (CASP3) expression with prognosis in pediatric classical Hodgkin lymphoma.

The search for clinically relevant molecular markers in classical Hodgkin lymphoma (cHL) is hampered by the histopathological complexity of the disease, resulting from the admixture of a small number of neoplastic Hodgkin and Reed-Sternberg (H-RS) cells with an abundant and heterogeneous microenvironment. In this study, we evaluated gene expression profiles of 11 selected genes previously proposed as a molecular score for adult cHL, aiming to validate its application in the pediatric setting. Assays were performed by RT-qPCR from formalin-fixed paraffin-embedded (FFPE) lymph nodes in 80 patients with cHL. Selected genes were associated with cell cycle (CENPF, CDK1, CCNA2, CCNE2, and HMMR), apoptosis (BCL2, BCL2L1, and CASP3), and monocytes/macrophages (LYZ and STAT1). Despite using controlled preanalytical and analytical strategies, we were not able to validate the 11-gene score to be applied in pediatric cHL. Principal component analysis (PCA) disclosed 3 components that accounted for 65.7% of the total variability. The second PC included microenvironment and apoptosis genes, from which CASP3 expression was associated with a short time of progression-free survival, which impact was maintained in the unfavorable risk group, Epstein-Barr virus-negative cases, and multivariate analysis (P < .05). Because this is a counterintuitive association, CASP3 active expression was assessed at the protein level in H-RS cells by double immunohistochemistry. In contrast to the association of mRNA levels with a poor therapeutic response, a high number of cleaved CASP3+ cells were associated with longer progression-free survival (P = .03) and overall survival (P = .002). Our results demonstrate the feasibility of using FFPE samples as RNA source for molecular prognostication, but argue against the concept of direct and wide applicability of molecular scores in cHL. We reinforce the potential of CASP3 as an interesting target to be explored in adult and pediatric cHL, and alert for its dual biological role in H-RS cells and tumor microenvironment.

Interleukin 10 (IL10) proximal promoter polymorphisms beyond clinical response in classical Hodgkin lymphoma: Exploring the basis for the genetic control of the tumor microenvironment.

Interleukin-10 (IL10) is an immune regulatory cytokine. Single nucleotide polymorphisms (SNPs) in IL10 promoter have been associated with prognosis in adult classical Hodgkin lymphoma (cHL). We analyzed IL10 SNPs -1082 and -592 in respect of therapy response, gene expression and tumor microenvironment (TME) composition in 98 pediatric patients with cHL. As confirmatory results, we found that -1082AA/AG; -592CC genotypes and ATA haplotype were associated with unfavourable prognosis: Progression-free survival (PFS) was shorter in -1082AA+AG (72.2%) than in GG patients (100%) (P = 0.024), and in -592AA (50%) and AC (74.2%) vs. CC patients (87.0%) (P = 0.009). In multivariate analysis, the -592CC genotype and the ATA haplotype retained prognostic impact (HR: 0.41, 95% CI 0.2-0.86; P = 0.018, and HR: 3.06 95% CI 1.03-9.12; P = 0.044, respectively). Our analysis further led to some new observations, namely: (1) Low IL10 mRNA expression was associated with -1082GG genotype (P = 0.014); (2) IL10 promoter polymorphisms influence TME composition;-1082GG/-592CC carriers showed low numbers of infiltrating cells expressing MAF transcription factor (20 vs. 78 and 49 vs. 108 cells/mm2, respectively; P< 0.05); while ATA haplotype (high expression) associated with high numbers of MAF+ cells (P = 0.005). Specifically, -1082GG patients exhibited low percentages of CD68+MAF+ (M2-like) intratumoral macrophages (15.04% vs. 47.26%, P = 0.017). Considering ours as an independent validation cohort, our results give support to the clinical importance of IL10 polymorphisms in the full spectrum of cHL, and advance the concept of genetic control of microenvironment composition as a basis for susceptibility and therapeutic response.

Diagnosing lymphoma in a setting with a high burden of infection: a pediatric case of Epstein-Barr virus-associated aggressive B-cell lymphoma with t(8;14) (q23;q32) and extensive necrosis mimicking tuberculosis.

The association of lymphoma with necrotic granuloma can pose diagnostic challenges and delay treatment, especially in settings with a high burden of infection. In these settings, the timely use of cytogenetic and molecular methods is most relevant. Here, we report a case of B-cell lymphoma with t (8;14) in a 5-year-old male child. The lymphoma was associated with necrotic granuloma and was initially misdiagnosed as tuberculosis. Polymerase chain reaction was used to detect clonal lymphoproliferation and to rule out Mycobacterium tuberculosis infection. Tumor cells harbored Epstein-Barr virus and expressed CD20, CD10, BCL6, and Ki67 (30%), leading to the diagnosis of B-cell lymphoma with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma.

Prevalence of HPV infection in head and neck carcinomas shows geographical variability: a comparative study from Brazil and Germany.

Rising prevalence rates of high-risk human papillomaviruses (hrHPV) infection in oropharyngeal carcinoma (up to 80 %) have been reported in North America and Scandinavia. We have analysed 424 German and 163 Brazilian head and neck squamous cell carcinomas (HNSCC) from the oral cavity (OSCC), oropharynx (OPSCC) and hypopharynx (HPSCC) using p16 immunohistochemistry, HPV DNA PCR and sequencing, hrHPV DNA in situ hybridisation (ISH) and hrHPV E6/E7 RNA ISH. In the German series, 52/424 cases (12.3 %) were p16-positive/hrHPV-positive (OSCC 3.8 % [10/265], OPSCC 34.4 % [42/122], HPSCC 0 % [0/37]). In addition, there were 9 cases that were p16-positive/hrHPV-negative (5 OPSCC and 4 OSCC). In the Brazilian series, the overall hrHPV DNA prevalence by PCR was 11.0 % ([18/163]; OSCC 6 % [5/83], OPSCC 15.5 % [11/71], HPSCC 22.2 % [2/9]). Ten of these cases were hrHPV-positive/p16-positive. The remaining 8 hrHPV-positive/p16-negative cases were also negative in both ISH assays. Furthermore, 5 p16-positive/hrHPV-negative cases (2 OPSCC and 3 OSCC) were identified. In both series, HPV16 was by far the most common HPV type detected. We confirm that regardless of geographical origin, the highest hrHPV prevalence in HNSCC is observed in oropharyngeal carcinomas. The proportion of HPV-associated OPSCC was substantially higher in the German cohort than in the Brazilian series (34.4 vs. 15.5 %), and in both groups, the prevalence of hrHPV in OPSCC was much lower than in recent reports from North America and Scandinavia. We suggest, therefore, that it may be possible to define areas with high (e.g. USA, Canada, Scandinavia), intermediate (e.g. Germany) and low (e.g. Brazil) prevalences of HPV infection in OPSCC.

Diagnosing lymphoma in a setting with a high burden of infection: a pediatric case of Epstein-Barr virus-associated aggressive B-cell lymphoma with t(8;14) (q23;q32) and extensive necrosis mimicking tuberculosis

The association of lymphoma with necrotic granuloma can pose diagnostic challenges and delay treatment, especially in settings with a high burden of infection. In these settings, the timely use of cytogenetic and molecular methods is most relevant. Here, we report a case of B-cell lymphoma with t (8;14) in a 5-year-old male child. The lymphoma was associated with necrotic granuloma and was initially misdiagnosed as tuberculosis. Polymerase chain reaction was used to detect clonal lymphoproliferation and to rule out Mycobacterium tuberculosis infection. Tumor cells harbored Epstein-Barr virus and expressed CD20, CD10, BCL6, and Ki67 (30%), leading to the diagnosis of B-cell lymphoma with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma.

Analysis of biological and technical variability in gene expression assays from formalin-fixed paraffin-embedded classical Hodgkin lymphomas.

Formalin-fixed paraffin-embedded (FFPE) tissues are invaluable sources of biological material for research and diagnostic purposes. In this study, we aimed to identify biological and technical variability in RT-qPCR TaqMan® assays performed with FFPE-RNA from lymph nodes of classical Hodgkin lymphoma samples. An ANOVA-nested 6-level design was employed to evaluate BCL2, CASP3, IRF4, LYZ and STAT1 gene expression. The most variable genes were CASP3 (low expression) and LYZ (high expression). Total variability decreased after normalization for all genes, except by LYZ. Genes with moderate and low expression were identified and suffered more the effects of the technical manipulation than high-expression genes. Pre-amplification was shown to introduce significant technical variability, which was partially alleviated by lowering to a half the amount of input RNA. Ct and Cy0 quantification methods, based on cycle-threshold and the kinetic of amplification curves, respectively, were compared. Cy0 method resulted in higher quantification values, leading to the decrease of total variability in CASP3 and LYZ genes. The mean individual noise was 0.45 (0.31 to 0.61 SD), indicating a variation of gene expression over ~1.5 folds from one case to another. We showed that total variability in RT-qPCR from FFPE-RNA is not higher than that reported for fresh complex tissues, and identified gene-, and expression level-sources of biological and technical variability, which can allow better strategies for designing RT-qPCR assays from highly degraded and inhibited samples.

Tumor microenvironment composition in pediatric classical Hodgkin lymphoma is modulated by age and Epstein-Barr virus infection.

Classical Hodgkin lymphoma (cHL) is characterized by a small number of neoplastic cells in a background of reactive cells. Children and adults differ in constitution and functionality of the immune system and it is possible that there may be age-related differences in tumor microenvironment composition in cHL. One hundred children with pediatric cHL were studied. Tumor-infiltrating lymphocytes were analyzed by immunohistochemistry (IHC) and image analysis. Epstein-Barr virus (EBV) status was determined by EBER-specific in situ hybridization and IHC. Results were analyzed in the context of age-group, histological characteristics and clinical follow-up. EBV-status was not associated with age-group. Children<10 years and EBV+ cases were characterized by a more intense T cell infiltrate, exhibiting a cytotoxic/Th1 profile, characterized by higher numbers of CD3+, CD8+, TIA1+ and TBET+ lymphocytes. Extranodal disease (p=0.016) and high number of GranzymeB+ lymphocytes (p=0.04) were independently associated with reduced progression-free survival (PFS). Yet, in EBV+ cases, improved outcome was observed in cases with low numbers of FOXP3+ lymphocytes (p=0.046), FOXP3/CD8 ratio<1 (p=0.021) and TBET/CMAF ratio<1 (p=0.017). By contrast, in EBV- cases, poor survival was observed in cases with extranodal disease (p=0.028), MC subtype (p=0.009) and high numbers of TIA1+ (p=0.044) and GranzymeB+ (p=0.04) lymphocytes. The results suggest that in EBV+ cHL an effective immune response directed against viral or tumor antigens may be triggered in the tumor microenvironment and that physiological and age-related changes of the immune system may also modulate the tumor microenvironment in pediatric cHL.

Disease patterns in pediatric classical Hodgkin lymphoma: a report from a developing area in Brazil.

Epidemiological patterns established about 20 years ago, divided classical Hodgkin lymphoma (cHL) in three entities with regard to Epstein-Barr virus (EBV) status and histological subtypes and suggested different epidemiological patterns associated with degree of economic development. Here, we investigated histopathological features and EBV association in 100 consecutive pediatric cHL cases occurring in Rio de Janeiro (Brazil). Age at diagnosis ranged from 3 to 18 years (median 14 years) with 27% of cases ≤10 years. Unexpectedly, we did not observe an early childhood peak with most cases occurring in the >10 years age group. Nodular sclerosis (NS) was the most frequent subtype (69%) and was more frequently observed in the >10 years age group, followed by mixed cellularity (MC, 23%) which was distributed equally between age groups. EBV was identified in 44.8% of cases, without preferential association with age groups (≤10 years vs. >10 years). MC cases were independently associated with EBV infection of tumour cells (p = 0.045) and with a CD4/CD20 ratio <1 in the microenvironment (p = 0.014). Our results suggest that a gradual shift from childhood peak to early adulthood peak may be observed in developing regions. The development of MC subtype may result from early exposure to EBV in the context of an impaired immune system reflected by a CD4/CD20 ratio <1. Conversely, it is possible that NS originates predominantly in the context of a better immune response against EBV and/or tumour antigens expressed in the neoplastic cells.

Molecular characterization of propolis-induced cell death in Saccharomyces cerevisiae.

Propolis, a natural product of plant resins, is used by the bees to seal holes in their honeycombs and protect the hive entrance. However, propolis has also been used in folk medicine for centuries. Here, we apply the power of Saccharomyces cerevisiae as a model organism for studies of genetics, cell biology, and genomics to determine how propolis affects fungi at the cellular level. Propolis is able to induce an apoptosis cell death response. However, increased exposure to propolis provides a corresponding increase in the necrosis response. We showed that cytochrome c but not endonuclease G (Nuc1p) is involved in propolis-mediated cell death in S. cerevisiae. We also observed that the metacaspase YCA1 gene is important for propolis-mediated cell death. To elucidate the gene functions that may be required for propolis sensitivity in eukaryotes, the full collection of about 4,800 haploid S. cerevisiae deletion strains was screened for propolis sensitivity. We were able to identify 138 deletion strains that have different degrees of propolis sensitivity compared to the corresponding wild-type strains. Systems biology revealed enrichment for genes involved in the mitochondrial electron transport chain, vacuolar acidification, negative regulation of transcription from RNA polymerase II promoter, regulation of macroautophagy associated with protein targeting to vacuoles, and cellular response to starvation. Validation studies indicated that propolis sensitivity is dependent on the mitochondrial function and that vacuolar acidification and autophagy are important for yeast cell death caused by propolis.

Fatores genéticos e ambientais na patogênese, constituição do microambiente tumoral e prognóstico clínico do linfoma de hodgkin pediátrico

O linfoma de Hodgkin classico (LHc) é caracterizado pelo pequeno número de células de Hodgkin e Reed-Sternberg (H-RS) em meio a um fundo de células não neoplásicas, principalmente T e B. Este microambiente tumoral tem sido considerado uma manifestação imune do hospedeiro contra as células H-RS. Uma vez que crianças e adultos apresentam diferenças quanto a constituição e funcionalidade do sistema imune, além de eventos patogênicos distintos, é de se esperar que o microambiente tumoral no LHc exiba diferenças entre crianças e adultos. Neste estudo, nós analisamos uma série de casos de LHc (100 casos) em relação as características clínico-histológicas, composição do microambiente tumoral através da imunomarcação para CD3, CD4, C-maf, T-bet, FoxP3, CD8, Tia-1, Granzima B (GrB) e CD20, além do impacto prognóstico destas características. O índice de proliferação celular (IPC) das células neoplásicas e benignas foi determinado a partir da imunoexpressão de Ki67. Os polimorfismos de base única (SNPs) da IL10 -1082A/G, -819C/T e -592C/A foram determinados através de PCR alelo-específica. Os SNPs de CTLA4 -1722 A/G, +49 A/G e CT60 A/G foram determinados por descriminação alélica. O vírus Epstein-Barr (EBV) foi determinado por hibridização in situ (EBER-ISH) e imunomarcação para LMP1. A idade ao diagnóstico variou de 3 a 18 anos (mediana 14 anos) com 27% dos casos 10 anos ao diagnóstico. A esclerose nodular (EN) foi o subtipo mais freqüente (69%), sendo comum nas crianças >10 anos, seguida da celularidade mista (CM, 23%), distribuída igualmente entre os grupos etários. 44,8% dos casos foram EBV+, sem associação com os grupos etários (10 anos). Os casos de CM estavam independentemente associados ao EBV (p= 0,045) e à relação CD4/CD20 4/mm2 (p= 0,045) estiveram independentemente associados a pior sobrevida livre de eventos (SLE). Um escore prognóstico foi construído e permitiu a separação dos casos em 3 grupos com diferenças na SLE (p= 0,005). Os genótipos da IL10 -1082GG e -592CC e o haplótipo GCC estiveram associados a características histológicas, baixo número de linfócitos Th2 e alto número de células T reguladoras (Tregs). O genótipo do CTLA4 CT60GG foi associado ao maior IPC das células H-RS. O SNP CT60A e o haplótipo +49A/CT60A estiveram relacionados ao maior número de linfócitos CD4+, enquanto o SNP CT60G e o genótipo cT60GG estiverem associados ao maior número de linfócitos CD8+ e Tregs. O haplótipo CTLA4 +49G/CT0G foi independentemente associado a pior SLE (p= 0,036). Em conclusão: 1) O LHc pediátrico no sudeste do Brasil deve ter um padrão epidemiológico intermediário entre o LHc pediátrico visto nas regiões menos e mais desenvolvidas. A histopatogênese da CM deve ser resultante de uma exposição precoce ao EBV num contexto de déficit imune, refletido pela razão CD4/CD20 <1 no microambiente tumoral; 2) Este é o 1º estudo a descrever a composição do microambiente tumoral no LHc pediátrico e a determinar que os SNPs da IL10 e CTLA4 são capazes de influenciar a composição do microambiente tumoral no LHc; e 3) O EBV tem uma influência significante na composição do microambiente tumoral e na modulação da resposta imune contra o tumor

Classical Hodgkin lymphoma (cHL) is characterized by a small number of neoplastic, Hodgkin and Reed-Sternberg (H-RS) cells in a background of non-neoplastic, mainly B and T cells. This tumor microenvironment has been considered to be a manifestation of host immune reactions to malignant cells. Since children and adults have difference in the constitution and functionality of the immune system, and pathogenic events differ in pediatric and adult cHL, it is likely that the tumor microenvironment in cHL may be distinct in the pediatric setting. In this study, we analyzed a series of pediatric cHL (100 cases) regarding the clinical and histological characteristics, as well as composition of the tumor microenvironment by CD3, CD4, C-maf, T-bet, FoxP3, CD8, Tia-1, Granzyme B (GrB) and CD20 immunostain and its prognostic impact. Proliferation index of neoplastic and benign infiltrating cells was determined by Ki67 immunostain. We determined also the IL10 -1082A/G, -819C/T and -592C/A genotype of single nucleotide polymorphisms (SNPs) and haplotypes by Allele-specific (AS) PCR and CTLA4 -1722 A/G, +49 A/G and CT60 A/G SNPs by allele discrimination with fluorogenic hydrolysis probes (Taqman® Applied Biosystems). Epstein-Barr virus (EBV) was determined by in situ hybridization (EBERs-ISH) and LMP1 immunostain. Age at diagnosis ranged from 3 to 18 years (median 14) with 27% of cases 10 years age group. Nodular sclerosis (NS) was the most frequent subtype (69%) and was more frequent in the >10 years age group, followed by mixed cellularity (MC, 23%) which was distributed equally between age groups. EBV was identified in 44.8% of cases, without preferential association with age groups (10 years). MC cases were independently associated with EBV (P= 0.045) and with a CD4/CD20 ratio 10) exhibiting a shift from more cytotoxic to more suppressive profile along with age. EBV influenced the lymphocyte composition with more CD8+, Tia-1+, GrB+, and T-bet+ (Th1) cells. Extranodal disease (P=0.016) and GrB+ lymphocytes >4 cells/mm2 (P= 0.045) were independently associated with worst event-free survival (EFS). A prognostic score was constructed and allowed to segregate the children in 3 groups with differences in EFS (P= 0.005). IL10 genotypes -1082GG and -592CC and haplotype GCC associated with histological characteristics, low number of Th2 and high number of regulatory T (Treg) cells. CTLA4 CT60GG genotype was associated with high H-RS proliferative index (Ki67>50%). The SNP CT60A and haplotype +49A/CT60A were related with high number of CD4+ T cells, while the SNP CT60G and the genotype CT60GG were associated with high number of CD8+ and Treg cells. The CTLA4 haplotype +49G/CT60G was independently associated with worst EFS (p= 0.036). In conclusion: 1) Pediatric cHL in Southeastern Brazil may have an intermediate epidemiological situation between childhood cHL in underdeveloped and developed regions. Histopathogenesis of MC subtype may result from early exposure to EBV in the context of an impaired immune system reflected by a CD4/CD20 ratio <1; 2) This the 1st study to describe the specific characteristics of tumor microenvironment composition in pediatric cHL and to determine that IL10 and CTLA4 SNPs are able to influence the tumor microenvironment composition in cHL; and 3) EBV-status has a significant influence in the tumor microenvironment composition and likely in the modulation of the imune response against the tumor

Cell cycle characteristics and Epstein-Barr virus are differentially associated with aggressive and non-aggressive subsets of Hodgkin lymphoma in pediatric patients.

We investigated the correlation of tumor characteristics with clinico-biological markers of aggressive disease, evaluated by Ann Arbor stage, risk group, B-symptoms, number of involved anatomic areas, mediastinal mass, nodular sclerosis (NS) grade, and risk, in pediatric Hodgkin lymphoma (HL). Leukopenia and extranodal disease influenced event-free survival (p = 0.032 and p = 0.041). In multivariate analysis, extranodal disease was associated with high number of tumor-infiltrating eosinophils (p = 0.035) and Ki67 < 50% (p = 0.024); B-symptoms with Ki67 > or =75% (p = 0.027) and high LDH levels (p = 0.001); and mediastinal mass with leukopenia (p = 0.048), NS grade II (p = 0.025), and high-risk (p = 0.046). Furthermore, low stages correlated with Ki67 > or =50% (p = 0.005) and Epstein-Barr virus (EBV) (p = 0.065). Low-risk NS was associated with EBV (p = 0.014). Hierarchical cluster analysis identified two clusters, one composed of high-risk patients and cell cycle and apoptosis features, and the other including low-risk patients, EBV, and low-risk NS. Our results show the association of biological markers with disease aggressiveness in pediatric HL.

MTR polymorphic variant A2756G and retinoblastoma risk in Brazilian children.

BACKGROUND: Polymorphisms in the genes of folate and methionine metabolism enzymes have been associated with some forms of cancer by affecting DNA synthesis, repair, and methylation. PROCEDURE: A case-control study of 72 retinoblastoma cases and 98 cancer-free children controls was performed to investigate whether the polymorphisms of the methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MTR A2756G), carrier of reduced folate 1 (RFC-1 A80G) and thymidylate synthase (TYMS 2R > 3R) altered the risk for retinoblastoma. RESULTS: MTR A2756G AG plus GG genotype frequencies were higher in patients than in controls (45% vs. 26%, P = 0.03). Individual carriers of the variant allele G had a 2.02 (95% CI: 1.05-3.92)-fold increased risk for retinoblastoma. In contrast, no association was observed with respect to MTHFR C677T and A1298C, RFC A80G, and TYMS polymorphisms. CONCLUSIONS: This study presents evidence for an association between the MTR A2756G polymorphism and retinoblastoma susceptibility in a Northeast population from Brazil.

Number of involved anatomic areas as a risk predictor in pediatric Hodgkin's lymphoma: a retrospective study.

OBJECTIVES: To determine if the number of involved anatomic areas can modify the standard risk groups in pediatric Hodgkin's lymphoma, identifying children who would benefit from a reduction in treatment intensity. METHODS: Retrospective study evaluating age, sex, histology, Ann-Arbor stage, presence of B symptoms, number of involved anatomic areas, risk grouping (favorable vs. unfavorable), and laboratory exams. All patients received doxorubicin-containing chemotherapy. Patients in complete remission for 5 years or longer were evaluated as for late effects. RESULTS: Sixty-nine patients (2-18 years) were included, 68% belonged to the unfavorable risk group. Overall survival and event-free survival were 94 and 87%, respectively. Late effects were screened in 46 cases. Advanced stage and > or = four involved anatomic areas had negative impact on event-free survival, while only the number of involved anatomic areas retained statistical significance when using Cox analysis (hazard ratio = 6.4, 95%CI = 1.08-38.33; p = 0.04). Risk groups were adjusted by number of involved anatomic areas (< four/> or = four involved anatomic areas), with a significant reallocation of patients (p = 0.008). Of the 30 patients with late effects, 21 were in the original unfavorable risk group and 14 (66.6%) could have been reallocated to the favorable risk group based on the number of involved anatomic areas. CONCLUSIONS: If re-stratification had been applied, a considerable number of children would have received less intensive treatment and, consequently, could have had lower chances of late effects. A prospective study could define if adjustment of risk group by number of involved anatomic areas would have any impact on survival rates.

Número de áreas anatômicas envolvidas como preditor de risco no linfoma de Hodgkin em crianças: um estudo retrospectivo / Number of involved anatomic areas as a risk predictor in pediatric Hodgkin's lymphoma: a retrospective study

OBJETIVO: Determinar se o número de áreas anatômicas envolvidas pode modificar os grupos de risco padrão no linfoma de Hodgkin pediátrico, identificando as crianças que poderiam se beneficiar de uma redução da intensidade do tratamento. MÉTODOS: Estudo retrospectivo com avaliação de idade, sexo, histologia, classificação de Ann-Arbor, presença de sintomas B, número de áreas anatômicas envolvidas, grupos de risco (favorável versus desfavorável) e exames laboratoriais. Todos os pacientes receberam quimioterapia com doxorrubicina. Os pacientes em remissão completa por 5 anos ou mais foram avaliados para a detecção de efeitos tardios. RESULTADOS: Sessenta e nove pacientes (2-18 anos) foram incluídos, sendo que 68 por cento pertenciam ao grupo de risco desfavorável. A sobrevida global e a sobrevida livre de eventos foram de 94 e 87 por cento, respectivamente. Os efeitos tardios foram detectados em 46 casos. Estágio avançado e > quatro áreas anatômicas envolvidas tiveram impacto negativo sobre a sobrevida livre de eventos, enquanto que o número de áreas anatômicas envolvidas apresentou significância estatística de acordo com a análise de Cox (razão de risco = 6,4; IC95 por cento = 1,08-38,33; p = 0,04). Os grupos de risco foram ajustados por número de áreas anatômicas envolvidas (< quatro/> quatro áreas anatômicas envolvidas), com uma significativa realocação de pacientes (p = 0,008). Dos 30 pacientes com efeitos tardios, 21 estavam no grupo de risco desfavorável original, e 14 poderiam ter sido realocados para o grupo de risco favorável com base no número de áreas anatômicas envolvidas. CONCLUSÃO: Se uma reestratificação tivesse sido aplicada, um número considerável de crianças teria recebido tratamento de menor intensidade e, consequentemente, poderia ter tido menores chances de apresentar efeitos tardios. Um estudo prospectivo poderia definir se o ajuste de grupos de risco pelo número de áreas anatômicas envolvidas teria algum impacto sobre ...

OBJECTIVE: To determine if the number of involved anatomic areas can modify the standard risk groups in pediatric Hodgkin's lymphoma, identifying children who would benefit from a reduction in treatment intensity. METHODS: Retrospective study evaluating age, sex, histology, Ann-Arbor stage, presence of B symptoms, number of involved anatomic areas, risk grouping (favorable vs. unfavorable), and laboratory exams. All patients received doxorubicin-containing chemotherapy. Patients in complete remission for 5 years or longer were evaluated as for late effects. RESULTS: Sixty-nine patients (2-18 years) were included, 68 percent belonged to the unfavorable risk group. Overall survival and event-free survival were 94 and 87 percent, respectively. Late effects were screened in 46 cases. Advanced stage and > four involved anatomic areas had negative impact on event-free survival, while only the number of involved anatomic areas retained statistical significance when using Cox analysis (hazard ratio = 6.4, 95 percentCI = 1.08-38.33; p = 0.04). Risk groups were adjusted by number of involved anatomic areas (< four/> four involved anatomic areas), with a significant reallocation of patients (p = 0.008). Of the 30 patients with late effects, 21 were in the original unfavorable risk group and 14 (66.6 percent) could have been reallocated to the favorable risk group based on the number of involved anatomic areas. CONCLUSION: If re-stratification had been applied, a considerable number of children would have received less intensive treatment and, consequently, could have had lower chances of late effects. A prospective study could define if adjustment of risk group by number of involved anatomic areas would have any impact on survival rates.