pRb2/p130 promotes radiation-induced cell death in the glioblastoma cell line HJC12 by p73 upregulation and Bcl-2 downregulation.
This study shows that in the glioblastoma hamster cell line HJC12 the retinoblastoma family member pRb2/p130 enhances gamma-radiation-induced cell death. In HJC12 cells the tetracycline-regulated expression of pRb2/p130 increased the percentage of gamma-radiation-induced apoptotic cells from 27 to 47%. pRb2/p130 overexpression was associated with the downregulation of the anti-apoptotic factor Bcl-2 and the upregulation of the steady-state protein levels of the pro-apoptotic transcription factor p73. In particular, RT-PCR showed a significant increase in the expression of the p73delta isoform when pRb2/p130 was overexpressed. The ability of pRb2/p130 to modulate apoptosis was not associated with its role in mediating G0/G1 arrest during cell cycle progression. Our data suggest a role for pRb2/p130 in glioblastoma gamma-radiation-induced cell death, indicating that the antitumoral action of pRb2/p130 can regulate both inhibition of cell cycle progression and induction of cell death.
Department of Pathology, Anatomy and Cell Biology, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA.
Bruna
B
Pucci
Pier Paolo
PP
Claudio
Valeria
V
Masciullo
Lorenza
L
Bellincampi
Alessandro
A
Terrinoni
Kamel
K
Khalili
Gerry
G
Melino
Antonio
A
Giordano
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D016923:Cell Death / Q000528:radiation effects; D016543:Central Nervous System Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D015536:Down-Regulation; D016193:G1 Phase / Q000528:radiation effects; D005720:Gamma Rays; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D005909:Glioblastoma / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D011506:Proteins; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D050717:Retinoblastoma-Like Protein p130; D014407:Tumor Cells, Cultured; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011506:Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D050717:Retinoblastoma-Like Protein p130; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins