title: Rolipram potentiates bevacizumab-induced cell death in human glioblastoma stem-like cells.
abstract: OBJECTIVE
  Glioblastoma cancer stem-like cells (GCSCs) promote themselves proliferation by secreting the vascular endothelial growth factor A (VEGFA) in an autocrine manner, positively regulated by phosphodiesterase IV (PDE4). In the current study, we investigated the putative cytotoxic effect of bevacizumab, a VEGFAblocker, alone and in combination with a specific inhibitor of PDE4 called rolipram on GCSCs isolated from human surgical tumor specimen with a focus on PI3K/AKT pathway.
  
  
  METHODS
  CD133+/CD15+ GCSCs were characterized by flow cytometry and expanded in a serum-free primary culture system. The cell survival, apoptosis, and protein expression values were measured using MTT assay, TUNEL staining and western blot, successively. Intracellular cAMP and free secreted VEGFAlevels were assessed by cAMP enzyme immunoassay and ELISA, respectively.
  
  
  RESULTS
  Bevacizumab suppressed GCSCs survival with IC50~6.5μg/ml and enhanced the levels of apoptosis, p53 and cleaved-caspase3 along with a decrease in free VEGFAlevels and ERKs activation. However, there was no significant modulation of AKT phosphorylation on serine 473, the intracellular PDE4A, VEGFAand cAMP levels. More cytotoxicity in co-treated cells coupled with a more substantial decline in the free VEGFAlevels and a greater increase in the quantities of p53 and cleaved-caspase3 compared to those treated with bevacizumab alone. Co-treatment reduced phospho-AKT, endogenous VEGFAand PDE4A values but elevated cAMP levels.
  
  
  CONCLUSIONS
  This study highlighted a booster cytotoxic effect of combined rolipram and bevacizumab treatment on the GCSCs primary culture, suggesting that this approach is warranted in treatment of GBMs overexpressing VEGFAand PDE4A.
authors.affiliation: Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Ramezani
authors.affiliation: Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Vousooghi
authors.affiliation: Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Fatemeh Ramezani
authors.initials: FR
authors.lastname: Kapourchali
authors.affiliation: Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Brain and Spinal Cord Injury Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahmoudreza
authors.initials: M
authors.lastname: Hadjighasem
authors.affiliation: Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Parisa
authors.initials: P
authors.lastname: Hayat
authors.affiliation: Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Naser
authors.initials: N
authors.lastname: Amini
authors.affiliation: Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; Neuroscience Department, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran. Electronic address: mt.joghataei@yahoo.com.
authors.forename: Mohammad Taghi
authors.initials: MT
authors.lastname: Joghataei
mesh_terms: D000068258:Bevacizumab / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D005909:Glioblastoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D020889:Rolipram / Q000819:agonists / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D009363:Neoplasm Proteins; D000068258:Bevacizumab; D020889:Rolipram
keywords: AKT; Co-treatment; Cyclic AMP; Glioblastoma multiforme; PDE4A; VEGF(A); p53