Recent natural selection identifies a genetic variant in a regulatory subunit of protein phosphatase 2A that associates with altered cancer risk and survival.
OBJECTIVE
A regulated p53-dependent stress response is crucial in suppressing tumor formation and mediating the response to commonly used cancer therapeutics. However, little is known about the human, inherited genetics of this important signaling pathway.


METHODS
Studies of human genetic variants in the p53 tumor suppressor gene and MDM2 oncogene have shown that single nucleotide polymorphisms (SNP) can affect p53 signaling, confer cancer risk, and alter outcome, and also suggest that the pathway is under evolutionary selective pressure. Here, we attempt to accelerate the identification of functional p53 pathway SNPs by incorporating these characteristics into an analysis of 142 genes that are known to affect p53 signaling.


RESULTS
We report that a genomic scan for recent natural selection denotes that of the 142 genes studied, the PPP2R5E gene that encodes a regulatory subunit of the tumor suppressing protein phosphatase 2A resides in a naturally selected genomic region. We go on to show that a selected SNP in PPP2R5E (epsilon-SNP2) associates with significant allelic differences in the onset (up to 19.2 years; P = 0.0002) and risk (odds ratio, up to 8.1; P = 0.0009) of soft tissue sarcoma development, as well as overall survival (relative risk, up to 3.04; P = 0.026).


CONCLUSIONS
The PPP2R5E gene is identified as harboring genetic variants that can affect human cancer and are possibly under evolutionary selection pressure.
Ludwig Institute for Cancer Research, University of Oxford, Oxford, United Kingdom.
Lukasz F
LF
Grochola
Alexei
A
Vazquez
Elisabeth E
EE
Bond
Peter
P
Würl
Helge
H
Taubert
Thomas H
TH
Müller
Arnold J
AJ
Levine
Gareth L
GL
Bond
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D050505:Mutant Proteins / Q000235:genetics / Q000502:physiology; D009369:Neoplasms / Q000235:genetics* / Q000401:mortality*; D020641:Polymorphism, Single Nucleotide / Q000502:physiology; D054648:Protein Phosphatase 2 / Q000235:genetics* / Q000502:physiology; D021122:Protein Subunits / Q000235:genetics / Q000502:physiology; D012307:Risk Factors; D012641:Selection, Genetic / Q000502:physiology; D016019:Survival Analysis; D013997:Time Factors; D055815:Young Adult
D050505:Mutant Proteins; C525692:PPP2R5E protein, human; D021122:Protein Subunits; D054648:Protein Phosphatase 2