Experimental Evidence On Di-region Theory Mechanism Of Carcinogenesis With Estrogens,Asbestos Etc

Di-region theory is a great breakthrough in the research field of the relationship between carcinogens and their structures, with wide attention domestically and abroad. In order to provide the experimental evidence and to explore the mechanism of carcinogenesis, we designed a modified alkaline elution experiment to examine the DNA cross-link ability of some selected procarcinogens: 17- 13 -Estradiol, Diethylstibestrol(DES) and the jointaction of 17- f3 -Estradiol and Pyrene, according to di-region theory.Estradiol and Diethylstilbestrol (DES) in estrogens are all carcinogens based upon animal experiments and epidemiological investigation. It is concluded from the di-region theory, a mechanism conception put forward by Professor Di Qianhuan, that the carcinogenesis of estrogens is switched on by the covalent cross-link between complementary DNA bases induced by them. We verified for the first time through DNA alkaline elution method that both estradiol and diethylstilbestrol can cause covalent cross-link between DNA-protein and DNA interstrands after metabolic activation with dosage correlation, but neither cholesterol nor pyrene which are non-carcinogens can lead to these sorts of cross-link in the same condition.It is known that there is a synergetic effect between estrogen and pollution of polycyclic aromatic hydrocarbons. Although non-carcinogenic pyrene alone cannot induce cross-link, its addition with equal molar quantity to estradiol culture causes synergically that the total and DNA interstrand cross-link ratio are respectively four and three times increasing than those in the cultivation with estradiol only. It would be shown that not only estradiol set off the formation of pyrene bi-radicals, but also the pyrene radicals arouse conversely the production of estradiol bi-radicals.The discovery of di-region theory predicts the mechanism of physical matters is also concerned with DNA cross-link. The DNA alkaline elution method showed that carcinogen asbestos produced certain degree of DNA cross-link with dosage correlation. However, the analogic non-carcinogen glassfiber did not show the ability of cross-link under the same condition.Liuxin (Major: Environmental Science)Directed by Di Qianhuan...