Sb. Hunter et al., MUTATIONS IN THE P53 GENE IN HUMAN ASTROCYTOMAS - DETECTION BY SINGLE-STRAND CONFORMATION POLYMORPHISM ANALYSIS AND DIRECT DNA-SEQUENCING, Modern pathology, 6(4), 1993, pp. 442-445
The p53 gene was examined in a series of formalin-fixed paraffin-embed
ded astrocytic neoplasms of various types by polymerase chain reaction
(PCR), single-strand conformation polymorphism analysis (SSCP), and d
irect sequencing of amplified DNA. PCR primers were designed to amplif
y three DNA fragments encompassing exons 5, 7, and 8 with splice sites
, including all four mutational ''hot spots'' within this gene. SSCP w
as performed in a polyacrylamide gel containing 10% glycerol. Two muta
tions were found among the 20 high and intermediate grade adult astroc
ytomas studied by this sensitive screening technique and confirmed by
sequencing of the PCR product. (1) An anaplastic astrocytoma disclosed
a T-A transversion in Codon 246 giving rise to a methionine to lysine
amino acid substitution. (2) A giant cell glioblastoma disclosed a G
to A transition in Codon 285 resulting in a glutamic acid to lysine su
bstitution. Both mutations were associated with loss of the normal all
ele. Twenty-three DNA fragments that disclosed no mutation by SSCP ana
lysis were confirmed to be negative by direct sequencing of amplified
DNA. No mutations were detected in a series of eight juvenile cerebell
ar astrocytomas, a biologically distinct form of low-grade astrocytoma
. Mutations of the p53 gene may play an important pathogenetic role in
a subset of human astrocytomas.