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p53 gene mutations in human tumor s. 50%. Greenblatt et al. (1995) Cancer Res . 54:4855. p53 and Ink4a are the two most frequently mutated genes in human tumors. The Basic Paradigm of p53 Function. Cellular Stresses (e.g. DNA damage). p53 (high). p53 (low). Apoptosis.
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p53 gene mutations in human tumors 50% Greenblatt et al. (1995) Cancer Res. 54:4855
p53 and Ink4a are the two most frequently mutated genes in human tumors
The Basic Paradigm of p53 Function Cellular Stresses (e.g. DNA damage) p53 (high) p53 (low) Apoptosis Cell cycle arrest
Li Fraumeni Syndrome An inherited neoplastic disease with autosomal dominant trait Characterised by multiple primary neoplasms in children and young adults A predominance of soft tissue sarcomas (e.g. breast)
Li Fraumeni Syndrome: Childhood and Adult Onset Cancers
Typical Li Fraumeni Syndrome Pedigree In approximately 70% of Li-Fraumeni cases, affected family members carry a germline mutation of one allele of the TP53 tumour suppressor gene.
p53 Mutations in Human Tumors are Found with High Frequency In the DNA Binding Domain In 143 families reported: point mutations (85%) deletions (9%) splice mutations (3.5%) insertions (2%)
p53 Binds DNA Ribbon Model Space Filling Model The most common mutation changes arginine 248, colored red here. Notice how it snakes into the minor groove of the DNA (shown in blue and green), forming a strong stabilizing interaction. When mutated to another amino acid, this interaction is lost. Other key sites of mutation are shown in pink, including arginine residues 175, 249, 273 and 282, and glycine 245.
p53 activates p21 (WAF1) GM=Dex inducible WT p53 DEL=Dex inducible mut p53 El-Deiry et al. (1993) Cell 75:817