Viruses as the cause of tumors

Karakteristika svih somatskih stanica je njihov ograničeni životni vijek te regulirana proliferacija, diferencijacija i preživljavanje što je potrebno da bi čitav organizam mogao normalno funkcionirati. Nakupljanje stanica koje čine tkivo bez fiziološke funkcije naziva se tumor ili neoplazma. Jedno od temeljnih svojstava tumora je klonalnost, nastanak iz jedne stanice koja počinje proliferirati. Nekontroliran rast karakterističan za tumorske stanice nastaje kao posljedica poremećaja regulacije staničnih sustava. Nastanak raka je proces niza promjena u kojem određene stanice postupno postaju zloćudne. Tumori koji imaju potencijal širenja po organizmu u kojem su nastali smatraju se malignima. Uzroci malignih transformacija povezuju se s vanjskim faktorima kao što su mutageni, odnosno karcinogeni, pogreškama u mehanizmima same stanice poput greške u replikaciji, a jedni od najvažnijih uzročnika su virusi. Onkolitički virusi su virusi koji se umnažaju u tumorskim stanicama, ubijaju ih i šire se među njima a da ne oštećuju ili inficiraju netumorske stanice. Tumorski virusi nisu važni samo zato što uzrokuju bolesti u ljudi, već i zato što imaju ključnu ulogu u istraživanju raka služeći kao modeli u molekularnim i staničnim istraživanjima transformacije stanice te zahvaljujući napretku u molekularnoj biologiji raka došlo je do poboljšanja u razvoju novih pristupa u liječenju raka. Cilj ovog rada je opisati svojstva tumorskih stanica, njihovo nastajanje i rast, objasniti utjecaj virusa na nastajanje tumora, pristupe u liječenju tumora te važnost cijepljenja u svrhu prevencije od bolesti.The characteristics of all somatic cells is their limited life duration and regulated proliferation, differentiation and survival necessary for the organism to function properly. The accumulation of cells that make up tissue without physiological function is called a tumor or neoplasm. One of the fundamental properties of a tumor is clonality, the emergence from a single cell that begins to proliferate. The uncontrolled growth characteristic of tumor cells arises as a result of impaired regulation of cellular systems. Cancer is the process of a series of changes in which certain cells gradually become malignant. Tumors that have the potential to spread to the organism in which they are produced are considered malignant. The causes of malignant transformations are related to external factors such as mutagens, that is, carcinogens, to errors in the mechanisms of the cell itself, such as a replication error, and viruses are one of the most important causes. Oncolytic viruses are viruses that multiply in tumor cells, kill them and spread among them without damaging or infecting non-tumor cells. Tumor viruses are not only important because they cause pain in humans, but also because they play a key role in cancer research by serving as models in molecular and cellular cell transformation studies, and thanks to advances in molecular cancer biology, improvements have been made in developing new approaches to cancer treatment . The objective of this thesis is to explain the properties of tumor cells, their formation and growth, to explain the impact of the virus on tumor formation, approaches to tumor treatment, and the importance of vaccination for the prevention of disease