Undersökning av global epigenetisk metyleringsstatus hos juvertumörer på hund

Abstract: Mammary tumors are the most frequent type of tumors in bitches in Sweden. Many studies have been published concerning mammary tumors, but there is still much to be learned about this disease. One has, since some time ago, had the knowledge that addition to or removal of methyl groups to genes can inhibit or activate gene-expression. Methylation and demethylation is a normal phenomenon in the body and it is essential for the development and survival of the individual. The risk of developing a tumor disease is increased if the global methylationstatus is changed; if oncogenes demethylates (activates) or if tumor suppressor genes methylates (inactivates). In the human medicine one has seen that there are differences in methylationstatus between different tumors. In this study tumor and normal tissue from ten dogs were examined with regard to methylationstatus. The results showed that there were not clear connections between the methylationstatus at the normal- or tumor tissue respectively, sometimes the normal tissue was hypermethylated in comparison to the tumor tissue and sometimes it was hypomethylated in comparison. The connection that one could see was that the malignant tumors tended to be hypermethylated in comparison to the benign tumors.