title: Ras inhibition amplifies cisplatin sensitivity of human glioblastoma.
abstract: Resistance to chemotherapy is a common feature of malignant gliomas. This resistance is mediated by receptor tyrosine kinase (RTK)-regulated signaling. p21-Ras protein is pivotal in the propagation of the signal originated from many RTKs. Our aim was to investigate whether inhibition of Ras pathway affects the response to cisplatin in malignant gliomas. We found an enhanced sensitivity to cisplatin of two glioblastoma cell lines expressing dominant negative Ras. Moreover, DN-Ras expressing cells, implanted in nude mice, resulted in being extremely sensitive to cisplatin. The growth of all the tumors was significantly inhibited by combining DN-Ras adenovirus infection with cisplatin treatment. The majority of glioma cells expressing DN-Ras underwent apoptosis in response to cisplatin. In vivo, DN-Ras alone did not influence the growth of tumors, suggesting that the effects of Ras-inhibition observed in vitro could not be extrapolated in vivo. The survival signal pathway transduced by Ras was essentially mediated by inhibition of caspase-9 cleavage via PI3K/Akt.
authors.affiliation: Dipartimento di Patologia Molecolare, IRCCS Istituto Neurologico Mediterraneo Neuromed, Pozzilli, Italy.
authors.forename: Samantha
authors.initials: S
authors.lastname: Messina
authors.forename: Carlo
authors.initials: C
authors.lastname: Leonetti
authors.forename: Giorgia
authors.initials: G
authors.lastname: De Gregorio
authors.forename: Valentina
authors.initials: V
authors.lastname: Affatigato
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ragona
authors.forename: Luigi
authors.initials: L
authors.lastname: Frati
authors.forename: Gabriella
authors.initials: G
authors.lastname: Zupi
authors.forename: Angela
authors.initials: A
authors.lastname: Santoni
authors.forename: Antonio
authors.initials: A
authors.lastname: Porcellini
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001932:Brain Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D004789:Enzyme Activation; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D018631:ras Proteins / Q000037:antagonists & inhibitors / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D018631:ras Proteins; C494918:AKT1 protein, human