Figure 2

Molecular analysis of G-16 glioblastoma cultured cells and paraffin block fragments. (A) Examples of LOH analysis showing deletion in 17p region at passage 10 (D17S1828 and D17S976 markers were used) and occurrence of the subpopulation of cells with 17p LOH in vivo (D17S1828 marker was used). Only a trace of the lost allele is observed in the 10 passage of G-16 cultured cells and in the paraffin block fragment A. The lost allele is marked with an arrow. (B) TP53 DNA sequencing results. The mutated nucleotide (TP53 exon 8, codon 272, GTG > ATG, Val > Met) is marked with arrows. 1) G-16 cultured cells at passage 4, G and A nucleotides are both detected, representing a heterozygous mutation. 2) G-16 cultured cells at passage 10, no wild type, only mutated nucleotide is detected. 3) Normal control template, only wild type DNA is detected. 4) G-16 paraffin block fragment A, both nucleotides are detected but G nucleotide is faint, suggesting a hemizygous mutation. 5) G-16 paraffin block fragment B, G and A nucleotides are both detected, representing a heterozygous mutation. N - corresponding normal tissue (blood) or normal, control template; A - G-16 paraffin block fragment A; B - G-16 paraffin block fragment B; 0, 4, 8, 10 - numbers of passages.