Clinical Prognostic Implications of Wnt Hub Genes Expression in Medulloblastoma.

Medulloblastoma is the most common type of pediatric malignant primary brain tumor, and about one-third of patients die due to disease recurrence and most survivors suffer from long-term side effects. MB is clinically, genetically, and epigenetically heterogeneous and subdivided into at least four molecular subgroups: WNT, SHH, Group 3, and Group 4. We evaluated common differentially expressed genes between a Brazilian RNA-seq GSE181293 dataset and microarray GSE85217 dataset cohort of pediatric MB samples using bioinformatics methodology in order to identify hub genes of the molecular subgroups based on PPI network construction, survival and functional analysis. The main finding was the identification of five hub genes from the WNT subgroup that are tumor suppressors, and whose lower expression is related to a worse prognosis for MB patients. Furthermore, the common genes correlated with the five tumor suppressors participate in important pathways and processes for tumor initiation and progression, as well as development and differentiation, and some of them control cell stemness and pluripotency. These genes have not yet been studied within the context of MB, representing new important elements for investigation in the search for therapeutic targets, prognostic markers or for understanding of MB biology.

IGFBP7 Fuels the Glycolytic Metabolism in B-Cell Precursor Acute Lymphoblastic Leukemia by Sustaining Activation of the IGF1R-Akt-GLUT1 Axis.

Increased glycolytic metabolism plays an important role in B-cell precursor Acute Lymphoblastic Leukemia (BCP-ALL). We previously showed that IGFBP7 exerts mitogenic and prosuvival effects in ALL by promoting IGF1 receptor (IGF1R) permanence on the cell surface, thus prolonging Akt activation upon IGFs/insulin stimulation. Here, we show that sustained activation of the IGF1R-PI3K-Akt axis concurs with GLUT1 upregulation, which enhances energy metabolism and increases glycolytic metabolism in BCP-ALL. IGFBP7 neutralization with a monoclonal antibody or the pharmacological inhibition of the PI3K-Akt pathway was shown to abrogate this effect, restoring the physiological levels of GLUT1 on the cell surface. The metabolic effect described here may offer an additional mechanistic explanation for the strong negative impact seen in ALL cells in vitro and in vivo after the knockdown or antibody neutralization of IGFBP7, while reinforcing the notion that it is a valid target for future therapeutic interventions.

MicroRNA expression profile predicts prognosis of pediatric adrenocortical tumors.

Pediatric adrenocortical tumors (ACT) are rare aggressive neoplasms with heterogeneous prognosis. Despite extensive efforts, identifying reliable prognostic factors for pediatric patients with ACT remains a challenge. MicroRNA (miRNA) signatures have been associated with cancer diagnosis, treatment response, and prognosis of several types of cancer. However, the role of miRNAs has been poorly explored in pediatric ACT. In this study, we performed miRNA microarray profiling on a cohort of 37 pediatric ACT and nine nonneoplastic adrenal (NNA) samples and evaluated the prognostic significance of abnormally expressed miRNAs using Kaplan-Meier plots, log-rank test, and Cox regression analysis. We identified a total of 98 abnormally expressed miRNAs; their expression profile discriminated ACT from NNAs. Among the 98 deregulated miRNAs, 17 presented significant associations with patients' survival. In addition, higher expression levels of hsa-miR-630, -139-3p, -125a-3p, -574-5p, -596, -564, -1321, and -423-5p and lower expression levels of hsa-miR-377-3p, -126-3p, -410, -136-3p, -29b-3p, -29a-3p, -337-5p, -143-3p, and 140-5p were significantly associated with poor prognosis, tumor relapse, and/or death. Importantly, the expression profile of these 17 miRNAs stratified patients into two groups of ACTs with different clinical outcomes. Although some individual miRNAs exhibit potential prognostic values in ACTs, only the 17 miRNA-based expression clustering was considered an independent prognostic factor for 5-year event-free survival (EFS) compared to other clinicopathological features. In conclusion, our study reports for the first time associations between miRNA profiles and childhood ACT prognosis, providing evidence that miRNAs could be useful biomarkers to discriminate patients with favorable and unfavorable clinical outcomes.

Induction therapy for acute lymphoblastic leukemia: incidence and risk factors for bloodstream infections.

Among the treatment-related acute toxic effects, risks for bloodstream infections (BSIs) are associated with several variables. The authors carried out a retrospective cohort study with 259 children and adolescents with ALL, treated with the GBTLI-LLA 2009 protocol, in order to assess the incidence of BSIs in the induction phase; to determine the risk factors for these BSIs; and to identify the related microorganisms and sensitivity profile of the microorganisms related to these infections. BSIs were documented in 19.3% of patients. The isolated microorganisms were 39 Gram-negative bacteria, 21 Gram-positive bacteria, and four fungi. There was a statistically significant risk of BSI between the variables: protocol for T-line-derived leukemia (Derived T Protocol) (p = 0.020), oral manifestations (p = 0.015), central venous catheter (p = 0.008), and bladder catheter (p = 0.004). BSI is a frequent event in ALL patients during the induction phase. The identification of these factors can allow the elaboration and improvement of strategies for the intensification of supportive care, prevention, and rapid treatment of infections.

High-throughput microRNA profile in adult and pediatric primary glioblastomas: the role of miR-10b-5p and miR-630 in the tumor aggressiveness.

Glioblastoma (GBM) is the most common primary malignant neoplasm of the central nervous system and, despite the standard therapy; the patients' prognoses remain dismal. The miRNA expression profiles have been associated with patient prognosis, suggesting that they may be helpful for tumor diagnosis and classification as well as predictive of tumor response to treatment. We described the microRNA expression profile of 29 primary GBM samples (9 pediatric GBMs) and 11 non-neoplastic white matter samples as controls (WM) by microarray analysis and we performed functional in vitro assays on these 2 most differentially expressed miRNAs. Hierarchical clustering analysis showed 3 distinct miRNA profiles, two of them in the GBM samples and a group consisting only of cerebral white matter. When adult and pediatric GBMs were compared to WM, 37 human miRNAs were found to be differentially expressed, with miR-10b-5p being the most overexpressed and miR-630 the most underexpressed. The overexpression of miR-630 was associated with reduced cell proliferation and invasion in the U87 GBM cell line, whereas the inhibition of miR-10b-5p reduced cell proliferation and colony formation in the U251 GBM cell line, suggesting that these miRNAs may act as tumor-suppressive and oncogenic miRNAs, respectively. The present study highlights the distinct epigenetic profiling of adult and pediatric GBMs and underscores the biological importance of mir-10b-5p and miR-630 for the pathobiology of these lethal tumors.

The TP53 p.R337H mutation is uncommon in a Brazilian cohort of pediatric patients diagnosed with ependymoma.

BACKGROUND: Ependymoma (EPN) is the third most common childhood cancer of the central nervous system. RELA fusion-positive EPN accounts for approximately 70% of all childhood supratentorial tumors and shows the worst prognosis among the supratentorial EPNs. TP53 mutation is infrequent in RELA fusions EPNs. In the population from the Southern region of Brazil, there is a high incidence of the germline TP53 p.R337H mutation that predisposes carriers to develop early-onset tumors. However, despite this high incidence, the frequency of this mutation among EPN patients remains to be determined. Here, we investigated the presence of the TP53 p.R337H mutation in a larger cohort of pediatric EPNs of three institutions located in the state of São Paulo, Brazil. METHODS: The TP53 p.R337H mutation was screened by conventional RT-PCR and Sanger sequencing in 49 pediatric EPNs diagnosed during the period from 1995 to 2016. RESULTS: We described for the first time a case of a 5-year-old girl with RELA fusion EPN with a heterozygous TP53 p.R337H mutation. CONCLUSIONS: The present finding indicates that the TP53 p.R337H germline mutation is uncommon in patients with EPN in Brazil and screening of pediatric patients RELA fusion EPN may be informative to better understand the role of TP53 germline mutations in the development and prognosis of these tumors.

MicroRNA profile of pediatric pilocytic astrocytomas identifies two tumor-specific signatures when compared to non-neoplastic white matter.

PURPOSES: Pilocytic astrocytoma (PA) is a low-grade neoplasm frequently found in childhood. PA is characterized by slow growth and a relatively good prognosis. Genetic mechanisms such as activation of MAPK, BRAF gene deregulation and neurofibromatosis type 1 (NF1) syndrome have been associated with PA development. Epigenetic signature and miRNA expression profile are providing new insights about different types of tumor, including PAs. METHODS: In the present study we evaluated global miRNA expression in 16 microdissected pediatric PA specimens, three NF1-associated PAs and 11 cerebral white matter (WM) samples by the microarray method. An additional cohort of 20 PAs was used to validate by qRT-PCR the expression of six miRNAs differentially expressed in the microarray data. RESULTS: Unsupervised hierarchical clustering analysis distinguished one cluster with nine PAs, including all NF1 cases and a second group consisting of the WM samples and seven PAs. Among 88 differentially expressed miRNAs between PAs and WM samples, the most underexpressed ones regulate classical pathways of tumorigenesis, while the most overexpressed miRNAs are related to pathways such as focal adhesion, P53 signaling pathway and gliomagenesis. The PAs/NF1 presented a subset of underexpressed miRNAs, which was also associated with known deregulated pathways in cancer such as cell cycle and hippo pathway. CONCLUSIONS: In summary, our data demonstrate that PA harbors at least two distinct miRNA signatures, including a subgroup of patients with NF1/PA lesions.

Reduced hydroxymethylation characterizes medulloblastoma while TET and IDH genes are differentially expressed within molecular subgroups.

INTRODUCTION: Medulloblastoma (MB) is an embryonal tumour that originates from genetic deregulation of cerebellar developmental pathways and is classified into 4 molecular subgroups: SHH, WNT, group 3, and group 4. Hydroxymethylation levels progressively increases during cerebellum development suggesting a possibility of deregulation in MB pathogenesis. The aim of this study was to investigate global hydroxymethylation levels and changes in TET and IDH gene expression in MB samples compared to control cerebellum samples. METHODS: The methods utilized were qRT-PCR for gene expression, dot-blot and immunohistochemistry for global hydroxymethylation levels and sequencing for the investigation of IDH mutations. RESULTS: Our results show that global hydroxymethylation level was decreased in MB, and low 5hmC level was associated with the presence of metastasis. TET1 expression levels were decreased in the WNT subgroup, while TET3 expression levels were decreased in the SHH subgroup. Reduced TET3 expression levels were associated with the presence of events such as relapse and death. Higher expression of IDH1 was observed in MB group 3 samples, whereas no mutations were detected in exon 4 of IDH1 and IDH2. CONCLUSION: These findings suggest that reduction of global hydroxymethylation levels, an epigenetic event, may be important for MB development and/or maintenance, representing a possible target in this tumour and indicating a possible interaction of TET and IDH genes with the developmental pathways specifically activated in the MB subgroups. These genes could be specific targets and markers for each subgroup.

Complementary genomic approaches highlight the PI3K/mTOR pathway as a common vulnerability in osteosarcoma.

Osteosarcoma is the most common primary bone tumor, yet there have been no substantial advances in treatment or survival in three decades. We examined 59 tumor/normal pairs by whole-exome, whole-genome, and RNA-sequencing. Only the TP53 gene was mutated at significant frequency across all samples. The mean nonsilent somatic mutation rate was 1.2 mutations per megabase, and there was a median of 230 somatic rearrangements per tumor. Complex chains of rearrangements and localized hypermutation were detected in almost all cases. Given the intertumor heterogeneity, the extent of genomic instability, and the difficulty in acquiring a large sample size in a rare tumor, we used several methods to identify genomic events contributing to osteosarcoma survival. Pathway analysis, a heuristic analytic algorithm, a comparative oncology approach, and an shRNA screen converged on the phosphatidylinositol 3-kinase/mammalian target of rapamycin (PI3K/mTOR) pathway as a central vulnerability for therapeutic exploitation in osteosarcoma. Osteosarcoma cell lines are responsive to pharmacologic and genetic inhibition of the PI3K/mTOR pathway both in vitro and in vivo.

Oral Mucositis in Pediatric Acute Lymphoblastic Leukemia Patients: Evaluation of Microbiological and Hematological Factors.

OBJECTIVE: to investigate the associations of oral microbiota, leucocytes count, neutrophil count, platelet counts and hemoglobin level, and the severity of oral mucositis in pediatric patients with acute lymphoblastic leukemia (ALL) receiving chemotherapy. MATERIALS AND METHODS: 71 prospective patients were included. Analyses of oral microbiota and blood sample were conducted on days 14 (D14) and 56 (D56) of the Brazilian GBTLI-99 treatment protocol. Herpes simplex virus (HSV) identification was performed by PCR followed by DNA sequencing analysis. Bacteria and fungi identification was obtained by standard microbiological culture tests. RESULTS: 103 episodes of mucositis occurred, being 65 at D14 and 38 at D56. Most cases positive for herpes viral DNA sequences were identified as HSV-1. At D14, we found a significant association between the severity of mucositis and presence of HSV-1 (p = 0.0347), Candida spp. (p = 0.0078), and low platelet count (p = 0.0064). At D56, we found a significant association between the severity of mucositis and the presence of HSV-1 (p = 0.0317), previous HSV-1 presence on D14 (p < 0.0001) and neutrophil count (p = 0.0211). CLINICAL RELEVANCE: the identification of risk factors for mucositis in children and adolescents may contribute to the development of new strategies for prevention and/or treatment, reducing the complications associated with this condition. CONCLUSIONS: the presence of HSV, platelet count, and Candida spp. presence at D14 of ALL induction treatment is associated with increased severity of mucositis in children and adolescents. At D56 of ALL treatment, mucositis severity was associated with neutrophil count, HSV presence, and previous presence of HSV (at D14).

Low PRKAB2 Expression Is Associated with Poor Outcomes in Pediatric Adrenocortical Tumors, and Treatment with Rottlerin Increases the PRKAB2 Level and Inhibits Tumorigenic Aspects in the NCI-H295R Adrenocortical Cancer Cell Line.

Pediatric adrenocortical tumors (ACTs) are rare, highly heterogeneous neoplasms with limited therapeutic options, making the investigation of new targets with potential therapeutic or prognostic purposes urgent. The PRKAB2 gene produces one of the subunits of the AMP-activated protein kinase (AMPK) complex and has been associated with cancer. However, little is known about the role AMPK plays in ACTs. We have evaluated how PRKAB2 is associated with clinical and biological characteristics in 63 pediatric patients with ACTs and conducted in vitro studies on the human NCI-H295R ACC cell line. An analysis of our cohort and the public ACC pediatric dataset GSE76019 showed that lower PRKAB2 expression was associated with relapse, death, metastasis, and lower event-free and overall survival rates. Multivariate analysis showed that PRKAB2 expression was an independent prognostic factor when associated with age, tumor weight and volume, and metastasis. In vitro tests on NCI-H295R cells demonstrated that Rottlerin, a drug that can activate AMPK, modulated several pathways in NCI-H295R cells, including AMPK/mTOR, Wnt/ß-catenin, SKP2, HH, MAPK, NFKB, and TNF. Treatment with Rottlerin decreased cell proliferation and migration, clonogenic capacity, and steroid production. Together, these results suggest that PRKAB2 is a potential prognostic marker in pediatric ACTs, and that Rottlerin is promising for investigating drugs that can act against ACTs.

Spindle assembly checkpoint gene expression in childhood adrenocortical tumors (ACT): Overexpression of Aurora kinases A and B is associated with a poor prognosis.

BACKGROUND: Pediatric adrenocortical tumors (ACT) are rare malignancies and treatment has a small impact on survival in advanced disease and the discovery of potential target genes could be important in new therapeutic approaches. METHODS: The mRNA expression levels of spindle checkpoint genes AURKA, AURKB, BUB, and BUBR1 were analyzed in 60 children with ACT by quantitative real time PCR. The anticancer effect of ZM447439, an experimental AURK inhibitor, was analyzed in a primary childhood ACT culture carrying the TP53 p.R337H mutation. RESULTS: A significant association was observed between malignancy as defined by Weiss score ≥3 and higher AURKA (2.0-fold, P = 0.01), AURKB (7.0-fold, P = 0.007), and BUBR1 (5.8-fold, P = 0.007) gene expression, and between unfavorable event (death or relapse) and higher expression of AURKA (6.0-fold, P = 0.034) and AURKB (17-fold, P = 0.013). Overexpression of AURKA and AURKB was associated with lower event-free survival in uni- (P < 0.001 and P = 0.006, respectively) and multivariate (P = 0.002 and P = 0.03, respectively) analysis. Significant lower Event free survival (EFS) was also observed in patients with moderate/strong immunostaining to AURKA (P = 0.012) and AURKB (P = 0.045). ZM447439 was able to induce inhibition of proliferation and colony formation in a primary childhood ACT culture carrying the TP53 p.R337H mutation. CONCLUSION: Our results suggest that AURKA and AURKB overexpression in pediatric ACT may be related to more aggressive disease and the inhibition of these proteins could be an interesting approach for the treatment of these tumors.

Classification and genetics of pediatric B-other acute lymphoblastic leukemia by targeted RNA sequencing.

Acute lymphoblastic leukemia (ALL) can be classified into different subgroups based on recurrent genetic alterations. Here, targeted RNA sequencing was used to identify the novel subgroups of ALL in 144 B-other and 40 "classical" ALL samples. The classical TCF3-PBX1, ETV6-RUNX1, KMT2A-rearranged, and BCR-ABL1, and novel P2RY8-CRLF2, ABL-, JAK2-, ZNF384-, MEF2D-, and NUTM1-fusions were easily identified by fusion transcript analysis. IGH-CRLF2 and IGH-EPOR were found by abnormally high levels of expression of CRLF2 or EPOR. DUX4-rearranged was identified by the unusual expression of DUX4 genes and an alternative exon of ERG, or by clustering analysis of gene expression. PAX5-driven ALL, including fusions, intragenic amplifications, and mutations were identified by single-nucleotide variant analysis and manual inspection using the IGV software. Exon junction analysis allowed detection of some intragenic ERG and IKZF1 deletions. CRLF2-high associated with initial white blood cell (WBC) counts of ≥50 × 103/µL and GATA3 risk alleles (rs3781093 and rs3824662), whereas ABL/JAK2/EPOR-fusions associated with high WBC counts, National Cancer Institute's high-risk classification, and IKZF1del. ZNF384-fusions associated with CALLA-negativity and NUTM1-fusions in infants. In conclusion, targeted RNA sequencing further classified 66.7% (96 of 144) B-other ALL cases. All BCP-ALL subgroups, except for iAMP21, hyperdiploid and hypodiploid cases, were identified. Curiously, we observed higher frequencies of females within B-rest ALLs and males in PAX5-driven cases.

Clinical outcomes of aspergillosis among paediatric and adult inpatients: A multicentre study in a Brazilian metropolitan area.

BACKGROUND: Invasive Aspergillosis (IA) is a disease of significant clinical relevance, especially among immunosuppressed patients, and is associated with high mortality rates. In this study, we evaluated the epidemiological features and clinical outcomes in children and adults with IA. METHODS: This was an observational, multicentre, prospective surveillance study of inpatients with IA at two different hospitals in Campinas, Brazil, between 2018 and 2021. RESULTS: A total of 44 patients were identified (54.5% males), with a median age of 42 years (interquartile range (IQR):19.25-59 years, varying between 1 and 89 years). The following baseline conditions were identified: 61.4% were oncohaematological patients and 20.5% were solid organ transplant recipients. Among oncohaematological patients, 77.8% exhibited severe or persistent neutropenia. The median time between the onset of neutropenia and the diagnosis of fungal infection was 20 days (IQR: 10.5-26 days; range, 0-68 days). The interval between neutropenia onset and fungal infection was longer in paediatric than in general hospital (average, 29 vs. 13.4 days; median 26 vs 11 days; p=0.010). After the diagnosis of IA, the survival rates were 44.2% and 30.0% at 180 and 360 days, respectively. Survival was greater in patients aged ≤ 21 years (p = 0.040; log-rank test). They observed no difference in IA mortality related to COVID-19 pandemic. CONCLUSION: High mortality associated with IA was observed in both hospitals. Individuals over the age of 21 have a lower survival rate than younger patients.

Musashi-1 regulates cell cycle and confers resistance to cisplatin treatment in Group 3/4 medulloblastomas cells.

Groups (Grp) 3 and 4 are aggressive molecular subgroups of medulloblastoma (MB), with high rates of leptomeningeal dissemination. To date, there is still a paucity of biomarkers for these subtypes of MBs. In this study, we investigated the clinical significance and biological functions of Musashi-1 (MSI1) in Grp3 and Grp4-MBs. First, we assessed the expression profile of MSI1 in 59 primary MB samples (15-WNT, 18-SHH, 9-Grp3, and 17-Grp4 subgroups) by qRT-PCR. MSI1 mRNA expression levels were also validated in an additional public dataset of MBs (GSE85217). The ROC curve was used to validate the diagnostic standards of MSI1 expression. Next, the potential correlated cell-cycle genes were measured by RNA-Seq. Cell cycle, cell viability, and apoptosis were evaluated in a Grp3/Grp4 MB cell line after knockdown of MSI1 and cisplatin treatment. We identified an overexpression of MSI1 with a high accuracy to discriminate Grp3/Grp4-MBs from non-Grp3/Grp4-MBs. We identified that MSI1 knockdown not only triggered transcriptional changes in the cell-cycle pathway, but also affected G2/M phase in vitro, supporting the role of knockdown of MSI1 in cell-cycle arrest. Finally, MSI1 knockdown decreased cell viability and sensitized D283-Med cells to cisplatin treatment by enhancing cell apoptosis. Based on these findings, we suggest that MSI1 modulates cell-cycle progression and may play a role as biomarker for Grp3/Grp4-MBs. In addition, MSI1 knockdown combined with cisplatin may offer a potential strategy to be further explored in Grp3/Grp4-MBs.

Prospective evaluation of HSV, Candida spp., and oral bacteria on the severity of oral mucositis in pediatric acute lymphoblastic leukemia.

BACKGROUND: Oral mucositis is a common collateral effect among the secondary complications resulting from chemotherapy. The objective of this study was to prospectively evaluate the association of HSV-1, Candida spp., and oral bacteria on the severity of oral mucositis in pediatric acute lymphoblastic leukemia (ALL). PROCEDURE: Seventy-one prospective patients were included. Analyses of oral microbiota were conducted on days 14 (D14) and 56 (D56) of the Brazilian GBTLI-99 treatment protocol. Herpes simplex virus (HSV) identification was performed by PCR followed by DNA sequencing analysis. Bacteria and fungi identification was obtained by standard microbiological culture tests. RESULTS: HSV-1 was found in 10.37% of individual patient samples. One sample was positive for HSV-4. On D14, we found an association between the severity of mucositis and the presence of HSV (p = 0.0347) and Candida spp. (p = 0.0078). At D56, we found an association between the severity of mucositis and the presence of HSV on D14 (p < 0.0001) and HSV presence (p = 0.0317). CONCLUSION: The presence of HSV, mainly HSV-1, and Candida spp. was associated with mucositis severity in pediatric ALL. No association could be found between bacterial CFU and severity of mucositis.

Glutathione levels are associated with methotrexate resistance in acute lymphoblastic leukemia cell lines.

Introduction: Methotrexate (MTX), a folic acid antagonist and nucleotide synthesis inhibitor, is a cornerstone drug used against acute lymphoblastic leukemia (ALL), but its mechanism of action and resistance continues to be unraveled even after decades of clinical use. Methods: To better understand the mechanisms of this drug, we accessed the intracellular metabolic content of 13 ALL cell lines treated with MTX by 1H-NMR, and correlated metabolome data with cell proliferation and gene expression. Further, we validated these findings by inhibiting the cellular antioxidant system of the cells in vitro and in vivo in the presence of MTX. Results: MTX altered the concentration of 31 out of 70 metabolites analyzed, suggesting inhibition of the glycine cleavage system, the pentose phosphate pathway, purine and pyrimidine synthesis, phospholipid metabolism, and bile acid uptake. We found that glutathione (GSH) levels were associated with MTX resistance in both treated and untreated cells, suggesting a new constitutive metabolic-based mechanism of resistance to the drug. Gene expression analyses showed that eight genes involved in GSH metabolism were correlated to GSH concentrations, 2 of which (gamma-glutamyltransferase 1 [GGT1] and thioredoxin reductase 3 [TXNRD3]) were also correlated to MTX resistance. Gene set enrichment analysis (GSEA) confirmed the association between GSH metabolism and MTX resistance. Pharmacological inhibition or stimulation of the main antioxidant systems of the cell, GSH and thioredoxin, confirmed their importance in MTX resistance. Arsenic trioxide (ATO), a thioredoxin inhibitor used against acute promyelocytic leukemia, potentiated MTX cytotoxicity in vitro in some of the ALL cell lines tested. Likewise, the ATO+MTX combination decreased tumor burden and extended the survival of NOD scid gamma (NSG) mice transplanted with patient-derived ALL xenograft, but only in one of four ALLs tested. Conclusion: Altogether, our results show that the cellular antioxidant defense systems contribute to leukemia resistance to MTX, and targeting these pathways, especially the thioredoxin antioxidant system, may be a promising strategy for resensitizing ALL to MTX.

MicroRNA-149-3p expression correlates with outcomes of adrenocortical tumor patients and affects proliferation and cell cycle progression of H295A adrenocortical cancer cell line.

Pediatric adrenocortical tumor (ACT) is a rare and aggressive neoplasm, with incidence in southern and southeastern Brazil 10-15 times higher than worldwide. Although microRNAs (miRNAs) have been reported to act as tumor suppressors or oncogenes in several cancers, the role of miR-149-3p in ACT remains unknown. In this study, we evaluated the expression of miR-149-3p in 67 pediatric ACT samples and 19 non-neoplastic adrenal tissues. The overexpression of miR-149-3p was induced in H295A cell line, and cell viability, proliferation, colony formation, and cell cycle were assessed by in miR-149-3p mimic or mimic control. In silico analysis were used to predict miR-149-3p putative target genes. CDKN1A expression at the mRNA and protein levels was evaluated by qRT-PCR and western blot, respectively. Higher miR-149-3p expression was associated with unfavorable ACT outcomes. Compared to the mimic control, miR-149-3p overexpression increased cell viability and colony formation, and affected cell cycle progression. Also, we identified CDKN1A as a potential miR-149-3p target gene, with decreased expression at both the gene and protein levels in miR-149-3p mimic cells. Collectively, these findings suggest that miR-149-3p promotes H295A cell viability by downregulating CDKN1A and provide evidence that miR-149-3p may be useful as a novel therapeutic target for pediatric ACT.

Identification of ITPR1 as a Hub Gene of Group 3 Medulloblastoma and Coregulated Genes with Potential Prognostic Values.

The Group 3 Medulloblastoma (Grp3-MB) is an aggressive molecular subtype with a high incidence of metastasis and deaths. In this study, were used an RNA sequencing data (RNA-Seq) from a Brazilian cohort of MBs to identify hub genes associated with the metastatic risk. Data validation were performed by using multiple large datasets from MBs (GSE85217, GSE37418, and EGAS00001001953). DESeq2 package in R software was used to identify the differentially expressed genes (DEGs) in our RNA-Seq data. The DEGs data were accessed to construct the modules/graphs of co-expression and to identify hub genes through Cytoscape platform. The coregulated genes were enriched by the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and the protein-protein interaction (PPI) network was visualized by Cytoscape. The Kaplan-Meier plotter and ROC curves were used to validate the diagnostic and prognostic values of specific biomarkers identified through this model. We identified that inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) as a downregulated hub gene, with a high diagnostic accuracy to Grp3-MBs and associated with tumor metastasis. In addition, we identified genes significantly correlated with ITPR1 that were associated with metastasis in Grp3-MB (ATP1A2, MTTL7A, and RGL1) and worst overall survival in MBs (ANTXR1 and RGL1). Our findings suggest that the ITPR1 hub gene is potentially involved in the metastatic process for Grp3-MB. Our data also provide evidence of targets that may serve as prognostic predictors and/or regulators for the metastatic process that maybe explored for further research of individualized therapy to Grp3-MBs.