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.
View Article and Find Full Text PDFAdvances in genomics have led to the identification of twelve relevant molecular subtypes within medulloblastoma (MB). The alpha subtype of Sonic hedgehog-driven MB is resistant to therapy (including smoothened inhibitors) due to activation of genes from the non-canonical SHH pathway, such as , , or . Using retrospective cohort microarray data, we found that is overexpressed in SHH alpha MB and patients profiled as resistant to SMO inhibitors compared to good responders.
View Article and Find Full Text PDFTimed degradation of the cyclin-dependent kinase inhibitor p27 by the E3 ubiquitin ligase F-box protein SKP2 is critical for T-cell progression into cell cycle, coordinating proliferation and differentiation processes. SKP2 expression is regulated by mitogenic stimuli and by Notch signaling, a key pathway in T-cell development and in T-cell acute lymphoblastic leukemia (T-ALL); however, it is not known whether SKP2 plays a role in the development of T-ALL. Here, we determined that SKP2 function is relevant for T-ALL leukemogenesis, whereas is dispensable for T-cell development.
View Article and Find Full Text PDFMedulloblastoma (MB) is the most common malignant brain tumor in children. Recent advances in molecular technologies allowed to classify MB in 4 major molecular subgroups: WNT, SHH, Group 3 and Group 4. In cancer research, cancer cell lines are important for examining and manipulating molecular and cellular process.
View Article and Find Full Text PDFIntroduction: 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.
View Article and Find Full Text PDFMedulloblastoma (MB) is a malignant childhood brain tumor which at molecular level is classified into at least four major subtypes: WNT, SHH, group C and group D differing in response to treatment. Previous studies have associated changes in expression levels and activation of certain HOX genes with MB development. In the present study, we investigate the role of HOX genes in two attributes acquired by tumor cells: migration and proliferation potential, as well as, in vivo tumorigenic potential.
View Article and Find Full Text PDFJ Genet
March 2016
The rennin-angiotensin-aldosterone system (RAAS) is a critical pathway in regulating blood pressure and salt/water homeostasis, possessing an intimate relationship with the development of systemic artery hypertension (SAH). Once hypertension is considered a risk factor for coronary artery disease (CAD), the RAAS is also related to this pathology. This investigation aimed to analyse if the frequencies of AGT M235T (rs699) and ACE I/D (rs4646994) polymorphisms are associated with CAD and SAH in African-Brazilians and Caucasian-Brazilians.
View Article and Find Full Text PDFChromosomal heterogeneity is a hallmark of most tumors and it can drive critical events as growth advantages, survival advantages, progression and karyotypic evolution. Medulloblastoma (MB) is the most common malignant central nervous system tumor in children. This work attempted to investigate chromosomal heterogeneity and instability profiles of two MB pediatric cell lines and their relationship with cell phenotype.
View Article and Find Full Text PDFComplement receptor 1 (CR1) gene polymorphisms that are associated with Knops blood group antigens may influence the binding of Plasmodium parasites to erythrocytes, thereby affecting susceptibility to malaria. The aim of this study was to evaluate the genotype and allele and haplotype frequencies of single-nucleotide polymorphisms (SNPs) of Knops blood group antigens and examine their association with susceptibility to malaria in an endemic area of Brazil. One hundred and twenty-six individuals from the Brazilian Amazon were studied.
View Article and Find Full Text PDFThe inflammatory process has been considered an important mediator for the development of atherosclerosis. Interleukin-1 beta (IL1B) is a precursor of interleukin-6 (IL6) in the acute phase of inflammatory response and their levels are elevated in patients with coronary artery disease. The aim of the present study was to further investigate the association of IL-1B and IL-6 gene polymorphisms and angiographically assessed coronary artery disease (CAD) in African- and Caucasian-Brazilians.
View Article and Find Full Text PDFBackground: Paraoxonases (PON) are members of an enzyme family involved in preventing low-density lipoprotein oxidation and therefore protecting against atherosclerotic plaque formation.
Methods: We studied the Met55Leu and Gln192Arg PON1 polymorphisms in 712 patients (437 Caucasian- and 275 African-Brazilians) who underwent coronary angiography.
Results: Among Caucasian-Brazilians, the homozygous 55LeuLeu frequency was higher among patients with significant coronary artery disease (CAD, obstructive lesions >/=50%) than among lesion-free controls (51% vs.