Clinical Trial: Role of p53 Gene in Metabolism Regulation in Patients With Li-Fraumeni Syndrome

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational

Official Title: Metabolic Regulation by Tumor Suppressor p53 in Li-Fraumeni Syndrome

Brief Summary:

This study will examine metabolic and biological factors in people with Li-Fraumeni syndrome, a rare hereditary disorder that greatly increases a person's susceptibility to cancer. Patients have a mutation in the p53 tumor suppressor gene, which normally helps control cell growth. This gene may control metabolism as well as cancer susceptibility, and the study findings may help improve our understanding of not only cancer but also other conditions, such as cardiovascular function.

Healthy normal volunteers and patients with the Li-Fraumeni syndrome and their family members may be eligible for this study. Candidates must be at least 18 years of age, in overall good health and cancer-free within 1 year of entering the study. Participants undergo the following procedures:

  • Blood tests for routine lab values and for research purposes.
  • ECG and echocardiogram (heart ultrasound) to evaluate heart structure and function.
  • Resting and exercise metabolic stress testing: The subject first relaxes in a chair wearing the facemask and then exercises on a stationary bicycle or treadmill while wearing the mask. This test uses the facemask to measure oxygen usage by the body to determine metabolic fitness. Electrodes are placed on the body to monitor the heart in an identical manner to a standard exercise stress test.
  • Magnetic resonance imaging of metabolism: The subject lies on a bed that slides into a large magnet (the MRI scanner) for up to 60 minutes. During scanning, the arm or leg muscles are stressed by inflating a blood pressure cuff and by exercising the limb for several minutes. Subjects may be asked to squeeze a rubber ball or exercise with a foot pedal. Immediately afterwards, the pressure in th

    Detailed Summary:

    We have previously reported that TP53 (encoding p53 protein), one of the most frequently mutated genes in human cancers, dose dependently modulates the balance between the utilization of oxidative and glycolytic pathways for energy generation in human colon cancer cells and mouse liver mitochondria. Though morphologically similar to their wild-type littermates, mice deficient in p53 display a gene dose-dependent decrease in aerobic exercise capacity, implying that p53 has functions beyond its well characterized cell cycle activities. These current findings have broad implications in fields ranging from cancer and aging research to cardiovascular physiology.

    In the Li-Fraumeni familial cancer syndrome (LFS), affected individuals harbor a germline mutation in TP53, hence they are heterozygous with reduced wild-type p53 activity. We hypothesize that the heterozygous individuals will display alterations in aerobic capacity and metabolism that previously has been unappreciated. This IRB proposal translates our experimental observation to human subjects in collaboration with extramural groups studying this rare familial syndrome. The results may not only help clarify why mutations of p53 gene are so common in cancers by potentially conferring metabolic advantages in tumorigenesis, but they may also give us an opportunity to understand a fundamental regulatory mechanism in cellular energy generation relevant to other processes.


    Sponsor: National Heart, Lung, and Blood Institute (NHLBI)

    Current Primary Outcome: Non-invasively measure aerobic exercise capacity and metabolism

    Original Primary Outcome:

    Current Secondary Outcome:

    • Non-invasively measure markers of mitochondrial function by magnetic resonance spectroscopy (MRS) in response to transient ischemic stress
    • Measure oxygen consumption, protein and RNA levels of p53-regulated mitochondrial genes using blood cells and other tissue samples if available.


    Original Secondary Outcome:

    Information By: National Institutes of Health Clinical Center (CC)

    Dates:
    Date Received: November 25, 2006
    Date Started: November 21, 2006
    Date Completion:
    Last Updated: April 21, 2017
    Last Verified: April 4, 2017