The p53 Gene is a Tumor Suppressor Gene
The p53 gene is a gene that codes for a protein that inhibits the development and growth of tumors (in addition to other functions). It is known as a tumor suppressor gene. If this gene is mutated –- that is, altered in some way by either the environment or inheritance, cancers can develop and grow out of control.
p53 Gene Mutation is Common
A mutation in the p53 gene (located on chromosome 17) is the most common mutation found in cancer cells, and is present in over 50% of cancers.
What Does the p53 Gene Do?
The p53 gene is responsible for proteins that can either repair damaged cells, or cause damaged cells to die, a process called apoptosis. When the gene is not working due to a mutation, these proteins that repair cells or eliminate damaged cells are not produced, and abnormal cells are allowed to divide and grow.
A very simplistic way to look at the p53 gene would be to picture yourself as the p53 gene, and a plumber as one of the proteins you can control. If you have a water leak and you are “functioning properly,” you would be able to make a phone call to the plumber. The plumber could then come to your home and either repair the leaky faucet, or remove it completely to stop the water leak. If you were unable to make the call (analogous to a faulty p53 gene), the plumber would not be called and the leak would continue (analogous to cancer cells dividing), and eventually flood your home.
What Causes Damage to the p53 Gene?
The p53 gene can be damaged (mutated) by cancer-causing substances in the environment, such as tobacco smoke. It may also be absent in some people from birth. People that inherit only one copy of the p53 gene (Li-Fraumeni syndrome) are predisposed to developing cancer later in life.
Importance of the p53 Gene in Lung Cancer
An understanding of the p53 gene and the proteins that it codes for may lead to better methods of diagnosing and treating lung cancer in the future.
Sources:
American Cancer Society. Oncogenes, Tumor Suppressor Genes, and Cancer. Updated 12/27/11. http://www.cancer.org/Cancer/CancerCauses/GeneticsandCancer/OncogenesandTumorSuppressorGenes/oncogenes-tumor-suppressor-genes-and-cancer-mutations-and-cancer
Demirhan, O. et al. Alternations in p16 and p53 genes and chromosomal findings in patients with lung cancer: Fluorescence in situ hybridization and cytogenetic studies. Cancer Epidemiology. 2010 May 3. (Epub ahead of print).
Farnebo, M. et al. The p53 tumor supprossor: a master regulator of diverse cellular processes and therapeutic target in cancer. Biochemical and Biophysical Research Communications. 2010. 396(1):85-9.
Hecht. S. Progress and challenges in selected areas of tobacco carcinogenesis. Chemical Research in Toxicology. 2008. 21(1):160-71.
National Center for Biotechnology Information (NCBI). The p53 tumor suppressor protein. Accessed 06/29/10. http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gnd&part=thep53tumorsuppressorprotein
Pfeifer, G. and A. Besaratinia. Mutational spectra of human cancer. Human Genetics. 2009. 125(5-6):493-506.
