title: Energy balance, the PI3K-AKT-mTOR pathway genes, and the risk of bladder cancer.
abstract: We evaluated the association between energy balance and risk of bladder cancer and assessed the joint effects of genetic variants in the mammalian target of rapamycin (mTOR) pathway genes with energy balance. The study included 803 Caucasian bladder cancer patients and 803 healthy Caucasian controls matched to cases by age (+/-5 years) and gender. High energy intake [odds ratio, 1.60; 95% confidence interval (95% CI), 1.23-2.09] and low physical activity (odds ratio, 2.82; 95% CI, 2.10-3.79) were each associated with significantly increased risk of bladder cancer with dose-response pattern (P(trend) < 0.001). However, obesity (body mass index, > or =30) was not associated with the risk. Among 222 single nucleotide polymorphisms, 28 single nucleotide polymorphisms located in six genes of mTOR pathway were significantly associated with the risk. Further, the risk associated with high energy intake and low physical activity was only observed among subjects carrying a high number of unfavorable genotypes in the pathway. Moreover, when physical activity, energy intake, and genetic variants were analyzed jointly, the study population was clearly stratified into a range of low- to high-risk subgroups as defined energy balance status. Compared with subjects within the most favorable energy balance category (low energy intake, intensive physical activity, low number of unfavorable genotypes), subjects in the worst energy balance category (high energy intake, low physical activity, and carrying > or =7 unfavorable genotypes) had 21.93-fold increased risk (95% CI, 6.7-71.77). Our results provide the first strong evidence that physical activity, energy intake, and genetic variants in the mTOR pathway jointly influence bladder cancer susceptibility and that these results have implications for bladder cancer prevention.
authors.affiliation: Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center, 1155 Hermann Pressler Boulevard, Houston, TX 77030, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Lin
authors.forename: Jianming
authors.initials: J
authors.lastname: Wang
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Greisinger
authors.forename: H Barton
authors.initials: HB
authors.lastname: Grossman
authors.forename: Michele R
authors.initials: MR
authors.lastname: Forman
authors.forename: Colin P
authors.initials: CP
authors.lastname: Dinney
authors.forename: Ernest T
authors.initials: ET
authors.lastname: Hawk
authors.forename: Xifeng
authors.initials: X
authors.lastname: Wu
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002149:Energy Intake / Q000502:physiology; D004734:Energy Metabolism / Q000235:genetics*; D015444:Exercise / Q000502:physiology; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D012307:Risk Factors; D015398:Signal Transduction / Q000235:genetics*; D058570:TOR Serine-Threonine Kinases; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; C546842:MTOR protein, human