Ras inhibition amplifies cisplatin sensitivity of human glioblastoma.
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.
Messina
Samantha
S
Dipartimento di Patologia Molecolare, IRCCS Istituto Neurologico Mediterraneo Neuromed, Pozzilli, Italy.
Leonetti
Carlo
C
De Gregorio
Giorgia
G
Affatigato
Valentina
V
Ragona
Giuseppe
G
Frati
Luigi
L
Zupi
Gabriella
G
Santoni
Angela
A
Porcellini
Antonio
A
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
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