) A new approach for visualization and detailed analysis of DNA damage at the level of the single cell will be developed. The approach will be based on in situ ligation of double-stranded and hairpin shaped DNA probes with specific architectures that will bind to the ends of DNA in tissue sections. The probes will be designed to selectively detect various types of double strand breaks in cellular DNA. They will be used to find a specific marker of apoptotic DNA damage in order to distinguish it from DNA damage in necrosis, as well as from potentially reparable DNA damage in cells showing no morphological signs of apoptosis or necrosis. The probes will be tested in different models of apoptosis and nonapoptotic DNA damage. The methodology will also be used to study focal brain ischemia, to determine the percentage of different types of DNA damage in a variety of important brain regions. This determination will permit better assessment of cellular damage after ischemia onset, and will be helpful for development of better therapies for ischemic brain damage, as well as for the other CNS diseases characterized by various types of DNA damage. The proposed technology will allow simultaneous evaluation of several types of alterations in DNA at the level of single cell. It, therefore, can be used in molecular and cell biology research, as well as by clinicians in many fields, including pathology oncology, cardiology and the clinical neurosciences.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZCA1-RLB-Y (M1))
Program Officer
Pelroy, Richard
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Baylor College of Medicine
Schools of Medicine
United States
Zip Code
Widmayer, Marsha A; Browning, Jeffrey L; Gopinath, Shankar P et al. (2010) Increased intracranial pressure is associated with elevated cerebrospinal fluid ADH levels in closed-head injury. Neurol Res 32:1021-6
Baskin, David S; Ngo, Hop; Didenko, Vladimir V (2003) Thimerosal induces DNA breaks, caspase-3 activation, membrane damage, and cell death in cultured human neurons and fibroblasts. Toxicol Sci 74:361-8
Didenko, Vladimir V; Ngo, Hop; Baskin, David S (2003) Early necrotic DNA degradation: presence of blunt-ended DNA breaks, 3' and 5' overhangs in apoptosis, but only 5' overhangs in early necrosis. Am J Pathol 162:1571-8
Didenko, Vladimir V; Ngo, Hop; Minchew, Candace L et al. (2002) Caspase-3-dependent and -independent apoptosis in focal brain ischemia. Mol Med 8:347-52
Didenko, Vladimir V; Ngo, Hop N; Minchew, Candace et al. (2002) Apoptosis of T lymphocytes invading glioblastomas multiforme: a possible tumor defense mechanism. J Neurosurg 96:580-4
Didenko, Vladimir V; Ngo, Hop; Minchew, Candace L et al. (2002) Visualization of irreparable ischemic damage in brain by selective labeling of double strand blunt-ended DNA breaks. Mol Med 8:818-23
Zhang, Y; Widmayer, M A; Zhang, B et al. (1999) Suppression of post-ischemic-induced fos protein expression by an antisense oligonucleotide to c-fos mRNA leads to increased tissue damage. Brain Res 832:112-7
Didenko, V V; Boudreaux, D J; Baskin, D S (1999) Substantial background reduction in ligase-based apoptosis detection using newly designed hairpin oligonucleotide probes. Biotechniques 27:1130-2