TY - JOUR
T1 - Contributions of intrinsic mutation rate and selfish selection to levels of de novo HRAS mutations in the paternal germline
AU - Giannoulatou, Eleni
AU - McVean, Gilean
AU - Taylor, Indira B
AU - McGowan, Simon J
AU - Maher, Geoffrey J
AU - Iqbal, Zamin
AU - Pfeifer, Susanne P
AU - Turner, Isaac
AU - Burkitt Wright, Emma M M
AU - Shorto, Jennifer
AU - Itani, Aysha
AU - Turner, Karen
AU - Gregory, Lorna
AU - Buck, David
AU - Rajpert-De Meyts, Ewa
AU - Looijenga, Leendert H J
AU - Kerr, Bronwyn
AU - Wilkie, Andrew O M
AU - Goriely, Anne
PY - 2013/12/10
Y1 - 2013/12/10
N2 - The RAS proto-oncogene Harvey rat sarcoma viral oncogene homolog (HRAS) encodes a small GTPase that transduces signals from cell surface receptors to intracellular effectors to control cellular behavior. Although somatic HRAS mutations have been described in many cancers, germline mutations cause Costello syndrome (CS), a congenital disorder associated with predisposition to malignancy. Based on the epidemiology of CS and the occurrence of HRAS mutations in spermatocytic seminoma, we proposed that activating HRAS mutations become enriched in sperm through a process akin to tumorigenesis, termed selfish spermatogonial selection. To test this hypothesis, we quantified the levels, in blood and sperm samples, of HRAS mutations at the p.G12 codon and compared the results to changes at the p.A11 codon, at which activating mutations do not occur. The data strongly support the role of selection in determining HRAS mutation levels in sperm, and hence the occurrence of CS, but we also found differences from the mutation pattern in tumorigenesis. First, the relative prevalence of mutations in sperm correlates weakly with their in vitro activating properties and occurrence in cancers. Second, specific tandem base substitutions (predominantly GC>TT/AA) occur in sperm but not in cancers; genomewide analysis showed that this same mutation is also overrepresented in constitutional pathogenic and polymorphic variants, suggesting a heightened vulnerability to these mutations in the germline. We developed a statistical model to show how both intrinsic mutation rate and selfish selection contribute to the mutational burden borne by the paternal germline.
AB - The RAS proto-oncogene Harvey rat sarcoma viral oncogene homolog (HRAS) encodes a small GTPase that transduces signals from cell surface receptors to intracellular effectors to control cellular behavior. Although somatic HRAS mutations have been described in many cancers, germline mutations cause Costello syndrome (CS), a congenital disorder associated with predisposition to malignancy. Based on the epidemiology of CS and the occurrence of HRAS mutations in spermatocytic seminoma, we proposed that activating HRAS mutations become enriched in sperm through a process akin to tumorigenesis, termed selfish spermatogonial selection. To test this hypothesis, we quantified the levels, in blood and sperm samples, of HRAS mutations at the p.G12 codon and compared the results to changes at the p.A11 codon, at which activating mutations do not occur. The data strongly support the role of selection in determining HRAS mutation levels in sperm, and hence the occurrence of CS, but we also found differences from the mutation pattern in tumorigenesis. First, the relative prevalence of mutations in sperm correlates weakly with their in vitro activating properties and occurrence in cancers. Second, specific tandem base substitutions (predominantly GC>TT/AA) occur in sperm but not in cancers; genomewide analysis showed that this same mutation is also overrepresented in constitutional pathogenic and polymorphic variants, suggesting a heightened vulnerability to these mutations in the germline. We developed a statistical model to show how both intrinsic mutation rate and selfish selection contribute to the mutational burden borne by the paternal germline.
KW - Adult
KW - Aged
KW - Aging/blood
KW - Carcinogenesis/genetics
KW - Codon/genetics
KW - Costello Syndrome/genetics
KW - Germ Cells/chemistry
KW - Humans
KW - Male
KW - Middle Aged
KW - Models, Statistical
KW - Mutation/genetics
KW - Proto-Oncogene Mas
KW - Proto-Oncogene Proteins p21(ras)/genetics
KW - Selection, Genetic/genetics
UR - http://www.scopus.com/inward/record.url?scp=84890285897&partnerID=8YFLogxK
U2 - 10.1073/pnas.1311381110
DO - 10.1073/pnas.1311381110
M3 - Article
C2 - 24259709
SN - 0027-8424
VL - 110
SP - 20152
EP - 20157
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 50
ER -