Enhanced recognition of hydroxyl radical modified plasmid DNA by circulating cancer antibodies.
Reactive oxygen species have been implicated in various human diseases which are also responsible for the elimination of invading pathogens. In disease state and inflammatory responses, the excess of these radicals damage cellular macromolecules. DNA is susceptible to attacks by OH-induced damage. Oxidative DNA damage is an important factor in mutagenesis and carcinogenesis. In the present study, purified plasmid Bluescript DNA was modified by hydroxyl radical. Modifications incurred in DNA were characterized by physico-chemical techniques. Sera from patients of cancer were studied for their binding to native and hydroxyl radical modified plasmid DNA. Direct binding ELISA and competition binding results indicated that autoantibodies in cancer showed higher recognition to ROS-plasmid DNA as compared to the native form. Retarded mobility of the immune complex formation between IgG isolated from cancer sera using native and ROS-plasmid DNA as antigens reiterated preferential recognition of modified plasmid DNA by cancer autoantibodies. Therefore, it can be concluded that circulating autoantibodies in cancer sera bind preferentially to ROS-plasmid DNA as compared to native polymer. The data presented in the present communication suggest a role of ROS in the etiology of cancer.
Khan
F
F
Dept. of Biochemistry, Faculty of Medicine, A.M.U. Aligarh, India.
Ali
A
A
Ali
R
R
D000912:Antibodies, Neoplasm / Q000737:chemistry*; D001323:Autoantibodies / Q000737:chemistry; D001667:Binding, Competitive; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D017665:Hydroxyl Radical; D007074:Immunoglobulin G / Q000737:chemistry; D009369:Neoplasms / Q000378:metabolism; D009360:Neoplastic Cells, Circulating / Q000276:immunology*; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism*; D017382:Reactive Oxygen Species; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism
D000912:Antibodies, Neoplasm; D001323:Autoantibodies; D007074:Immunoglobulin G; D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; D004247:DNA; D015719:Single-Strand Specific DNA and RNA Endonucleases; D010100:Oxygen