Ahmad M Imtiaz, Ahmad Saheem
Department of Biochemistry, J. N. Medical College, Faculty of Medicine, AMU, Aligarh, (UP), India 202002.
Indian J Biochem Biophys. 2011 Aug;48(4):290-6.
Methylglyoxal (MG) has been implicated in mutagenesis and cancer. Present study probes the antigenicity of MG damaged DNA in cancer patients. Purified calf thymus DNA was damaged by the synergistic action of MG, lysine (Lys) and CuSO4 for 24 h at 37 degrees C. DNA modifications produced single-strand breaks, hyperchromicity in UV spectrum and increased fluorescence intensity. Binding characteristics of auto-antibodies in cancer patients were assessed by direct binding and inhibition ELISA. These antibodies exhibited enhanced binding with the modified DNA, as compared to the native form. The effect was more pronounced when affinity-purified IgG was used in place of the serum. In conclusion, MG-modified DNA presents unique epitopes which are recognized as non-self by the immune system and may, therefore, be one of the factors for the autoantibody induction in cancer patients.
甲基乙二醛（MG）与诱变和癌症有关。本研究探讨了MG损伤的DNA在癌症患者中的抗原性。纯化的小牛胸腺DNA在37℃下经MG、赖氨酸（Lys）和CuSO4协同作用24小时而受损。DNA修饰产生了单链断裂、紫外光谱中的增色效应以及荧光强度增加。通过直接结合和抑制ELISA评估癌症患者自身抗体的结合特性。与天然形式相比，这些抗体与修饰后的DNA表现出更强的结合。当使用亲和纯化的IgG代替血清时，这种效应更为明显。总之，MG修饰的DNA呈现出独特的表位，被免疫系统识别为非自身物质，因此可能是癌症患者自身抗体诱导的因素之一。
