Benign tumors from the human nervous system express high levels of survivin and are resistant to spontaneous and radiation-induced apoptosis.
Survivin, an inhibitor of apoptosis, is over-expressed in foetal tissues and human cancers, but it is almost undetectable in normal tissues. Here we have assessed the level of the survivin protein in some benign tumors of the nervous system: meningioma, schwannoma, low-grade ependymoma, pilocytic astrocytoma and pituitary adenoma. Using immuno-blot analysis we present evidence that these low-grade tumors are positive for survivin expression. In agreement, flow cytometrical analysis showed that both spontaneous and radiation-induced apoptosis levels are very low in these neoplasms. Using host cell reactivation assay we have also shown that these tumor cells are proficient in the repair of gamma-ray-induced DNA damage. However, they are deficient in the removal of ultraviolet (UV) light-induced DNA photolesions, especially the shwannoma- and the pituitary adenoma-derived cells. These results suggest that survivin overexpression may be an early event in the stepwise tumoregenesis and hence could be responsible for the onset as well as the growth advantage during tumoregenic progression of malignant as well as benign neoplasms.
Hassounah
Maher
M
Department of Neurosciences, MBC# 76, Riadh, KSA.
Lach
Boleslaw
B
Allam
Ayman
A
Al-Khalaf
Huda
H
Siddiqui
Yunus
Y
Pangue-Cruz
Nancy
N
Al-Omeir
Abeer
A
Al-Ahdal
Mohammed N
MN
Aboussekhra
Abdelilah
A
D017209:Apoptosis / Q000502:physiology* / Q000528:radiation effects*; D045744:Cell Line, Tumor; D004249:DNA Damage / Q000528:radiation effects; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D005720:Gamma Rays; D016158:Genes, p53 / Q000235:genetics / Q000528:radiation effects; D006801:Humans; D015151:Immunoblotting; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis*; D009363:Neoplasm Proteins / Q000378:metabolism; D009423:Nervous System Neoplasms / Q000378:metabolism* / Q000473:pathology*; D015689:Oncogene Protein p21(ras) / Q000096:biosynthesis / Q000528:radiation effects; D000077022:Survivin; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays
C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D000077022:Survivin; D015689:Oncogene Protein p21(ras)