Ras inhibition amplifies cisplatin sensitivity of human glioblastoma

• Published in: Biochemical and biophysical research communications 2004-07, Vol.320 (2), p.493-500
• Main Authors: Messina, Samantha, Leonetti, Carlo, De Gregorio, Giorgia, Affatigato, Valentina, Ragona, Giuseppe, Frati, Luigi, Zupi, Gabriella, Santoni, Angela, Porcellini, Antonio
• Format: Article
• Language: English
• Subjects: Adenoviridae - genetics; Adenovirus; Animals; Antineoplastic Agents - pharmacology; Apoptosis; Brain Neoplasms - pathology; Cell Line, Tumor; Chemotherapy; Cisplatin - pharmacology; Drug resistance; Enzyme Activation; Gene therapy; Glioblastoma; Glioblastoma - pathology; Humans; Male; Mice; Mice, Nude; Neoplasm Transplantation; Phosphatidylinositol 3-Kinases - metabolism; Protein-Serine-Threonine Kinases - metabolism; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-akt; Ras; ras Proteins - antagonists & inhibitors; ras Proteins - genetics; Signal transduction
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2004.06.003

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.