title: HIF1A is Overexpressed in Medulloblastoma and its Inhibition Reduces Proliferation and Increases EPAS1 and ATG16L1 Methylation.
abstract: Genetic and epigenetic modifications are closely related to tumor initiation and progression and can provide guidance for understanding tumor functioning, potentially leading to the discovery of new therapies. Studies have associated hypoxia-related genes to tumor progression and chemo/radioresistance in brain tumors. Information on the expression profile of hypoxiarelated genes in pediatric medulloblastoma, although scarce, may reveal relevant information that could support treatment decisions.
  
  
  
  Our study focused on evaluation the of CA9, CA12, HIF1A, EPAS1, SCL2A1 and VEGF genes in 41 pediatric fresh-frozen medulloblastoma sample. Additionally, we analyzed the effect of hypoxia and normoxia in the pediatric medulloblastoma cell-line UW402. Furthermore, we assessed the effects of HIF1A knockdown in cell-proliferation and methylation levels of genes related to hypoxia, apoptosis and autophagy.
  
  
  
  qPCR was performed to evaluate mRNA levels, and Western blot to confirm HIF1A silencing in both patient samples and cell line. Pyrosequencing was performed to asses the methylation levels after HIF1A knockdown in the UW402 cell line.
  
  
  
  A higher HIF1A mRNA level was observed in MB patients when compared to the cerebellum (non-tumor match). In UW402 MB cell-line, chemically induced hypoxic resulted in an increase of mRNA levels of HIF1A, VEGF, SCL2A1 and CA9 genes. Additionally, HIF1A knockdown induced a decrease in the expression of hypoxia related genes and a decrease of 30% in cell proliferation was also observed. Also, a significant increase in the methylation of ATG16L1 promoter and decrease in the methylation of EPAS1 promoter were observed after HIF1A knockdown.
  
  
  
  HIF1A knockdown in medulloblastoma cells lead to decreased cellular proliferation, suggesting that HIF1A can be a potential therapeutic target to be explored in the medulloblastoma. However, the mechanisms behind HIF1A protein stabilization and function are very complex and more data need to be generated to potentially use HIF1A as a therapeutical target.
authors.affiliation: Department of Genetics, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Gustavo Alencastro Veiga
authors.initials: GAV
authors.lastname: Cruzeiro
authors.affiliation: Department of Pediatrics, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Maristella Bergamo
authors.initials: MB
authors.lastname: Dos Reis
authors.affiliation: Department of Genetics, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Vanessa Silva
authors.initials: VS
authors.lastname: Silveira
authors.affiliation: Department of Pediatrics, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Regia Caroline Peixoto
authors.initials: RCP
authors.lastname: Lira
authors.affiliation: Department of Surgery, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Carlos Gilberto
authors.initials: CG
authors.lastname: Carlotti
authors.affiliation: Department of Surgery, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Neder
authors.affiliation: Department of Surgery, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Ricardo Santos
authors.initials: RS
authors.lastname: Oliveira
authors.affiliation: Department of Pathology, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.|State University of Campinas, Cidade Universitária Zeferino Vaz - Barão Geraldo, 13083-970, Campinas, SP, Brazil.
authors.forename: Jose Andres
authors.initials: JA
authors.lastname: Yunes
authors.affiliation: Department of Pathology, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.|State University of Campinas, Cidade Universitária Zeferino Vaz - Barão Geraldo, 13083-970, Campinas, SP, Brazil.
authors.forename: Silvia Regina
authors.initials: SR
authors.lastname: Brandalise
authors.affiliation: Department of Pathology, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Simone
authors.initials: S
authors.lastname: Aguiar
authors.affiliation: Institute of Personalized Cancer Therapy, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States.
authors.forename: Agda Karina
authors.initials: AK
authors.lastname: Eterovic
authors.affiliation: Department of Genetics, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Luiz Gonzaga
authors.initials: LG
authors.lastname: Tone
authors.affiliation: Department of Pediatrics, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Scrideli
authors.affiliation: Department of Pediatrics, Ribeirao Preto Medicine School, University of Sao Paulo, Avenida dos Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Elvis Terci
authors.initials: ET
authors.lastname: Valera
mesh_terms: D000293:Adolescent; D017209:Apoptosis; D000071183:Autophagy-Related Proteins / Q000235:genetics*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D016022:Case-Control Studies; D049109:Cell Proliferation; D002528:Cerebellar Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002531:Cerebellum / Q000378:metabolism / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D007223:Infant; D008297:Male; D008527:Medulloblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D011401:Promoter Regions, Genetic; D014407:Tumor Cells, Cultured; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D000071183:Autophagy-Related Proteins; D051792:Basic Helix-Loop-Helix Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D000099162:Endothelial PAS Domain-Containing Protein 1; C518959:ATG16L1 protein, human; C497442:HIF1A protein, human
keywords: ATG16L1; EPAS1; HIF1A; epigenetics; hypoxia; medulloblastoma.