Abnormal proliferation of the epidermis is associated with cumulative unprotected exposure to ultraviolet radiation leading to the accumulation of somatic mutations. Recent research has shown that mitochondria not only play an important role in providing cellular energy, but also may have a central role in apoptosis and neoplasia. There are now several reports of mitochondrial genes that were previously thought to function only in energy production that have not been shown to be mutated in familiar tumor syndromes, and reports of acquired homoplasmic mitochondrial DNA (mtDNA) mutations in human tumors. This proposal seeks to test the role of mtDNA changes in the process of photoaging and aberrant keratinocyte hyperplasia. First, ultraviolet radiation will be used to induce photodamage and tumor production in the hairless mouse. The mtDNA will be studied from photodamaged skin and from benign and malignant epidermal neoplasms to determine the types of somatic mtDNA mutations in photodamaged mouse skin. Next, mtDNA mutations will be recovered from hyperproliferating keratinocytes by isolation of mitochondria and fusion into fibroblast cells that lack their own mtDNA to create cytoplasmic hybrid (cybrid) libraries. Individual cybrid clones will be screened for mtDNA mutations and the effect of these DNA changes will be analyzed. The cybrids will be studied for alterations in oxidative phosphorylation biochemistry and ATP production, as well as for alterations in cellular phenotype including growth characteristics, matrix metalloproteinases expression, ability to escape apoptosis, and ability to form tumors. The ability of mutant mtDNAs to become dominant over wild type will also be studied genetically in fusion assays. Finally, recovered mtDNA mutations will be returned to the live epidermis by the generation of transmitochondrial transgenic mice to study the ability of these mutations to alter growth and tumor development in the intact mouse epidermis. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR051552-02
Application #
7257090
Study Section
Arthritis, Connective Tissue and Skin Study Section (ACTS)
Program Officer
Baker, Carl
Project Start
2006-07-01
Project End
2009-05-31
Budget Start
2007-06-01
Budget End
2008-05-31
Support Year
2
Fiscal Year
2007
Total Cost
$196,744
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Sligh, James; Janda, Jaroslav; Jandova, Jana (2014) Mutations in BALB mitochondrial DNA induce CCL20 up-regulation promoting tumorigenic phenotypes. Mutat Res 769:49-58
Boyer, Jean Z; Jandova, Jana; Janda, Jaroslav et al. (2012) Resveratrol-sensitized UVA induced apoptosis in human keratinocytes through mitochondrial oxidative stress and pore opening. J Photochem Photobiol B 113:42-50
Jandova, Jana; Eshaghian, Alex; Shi, Mingjian et al. (2012) Identification of an mtDNA mutation hot spot in UV-induced mouse skin tumors producing altered cellular biochemistry. J Invest Dermatol 132:421-8
Jandova, Jana; Shi, Mingjian; Norman, Kimberly G et al. (2012) Somatic alterations in mitochondrial DNA produce changes in cell growth and metabolism supporting a tumorigenic phenotype. Biochim Biophys Acta 1822:293-300