Abstract: Gliomas are the most frequent primary tumors of central nervous system and represent a
heterogeneous group of tumors that originates from the glial cells. TP53, PTEN, and CDKN2A are
important tumor suppressor genes that encode proteins involved in sustaining cellular homeostasis
by different signaling pathways. Though genetic alterations in these genes play a significant role
in tumorigenesis, few studies are available regarding the incidence and relation of concomitant
TP53, PTEN, and CDKN2A alterations in gliomas. The purpose of this study was to evaluate
the occurrence of mutation and deletion in these genes, through single-strand conformational
polymorphism, array-comparative genomic hybridization, and fluorescence in situ hybridization
techniques, in 69 gliomas samples. Molecular results demonstrated a significant higher prevalence of
TP53, PTEN, and CDKN2A alterations in astrocytoma than other tumor subtypes, and heterozygous
deletion was the most frequent event. In addition, a significant association was observed between
TP53 and CDKN2A alterations (p = 0.0424), which tend to coexist in low grade astrocytomas
(5/46 cases (10.9%)), suggesting that they are early events in development of these tumors, and PTEN
and CDKN2A deletions (p = 0.0022), which occurred concomitantly in 9/50 (18%) patients, with
CDKN2A changes preceding PTEN deletions, present preferably in high-grade gliomas.
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