Genetic instability in cancer and telomeres

Trepotec, Željka (2012) Genetic instability in cancer and telomeres. Bachelor's thesis, Faculty of Science > Department of Biology.

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Abstract

Organisms have evolved complex adaptations for survival under the natural laws. On the same way, tumors are product of microevolution among individual cells. In the evolutionary history, they were present at the same time when single-cells started to form multicellular organism from integrated complex tissues in order to preserve the homeostasis. Modified cells are recognized by diverse control mechanisms, which then induce apoptosis (programmed cell death) or senescence, absence of mitosis and DNA replication. If modified cells escape these mechanisms, they can form a part of a huge deregulated cell mass called tumor. Just like every other cell, they also require an oxygen, nutrition and revulsive system for toxic metabolic products and growth factors. They establish a blood vessels all round them by the process called angiogenesis. In favorable environment they start to penetrate deeper in the tissue, or even to migrate to some new tissues by blood, forming metastases. Chromosomes are protected with telomeres, a nucleoprotein specific repetitive complex at their edges. Because of the specific properties of eukaryotic transcription and the enzyme DNA polymerase, telomeres are shortening with every mitotic cycle. There is an enzyme called telomerase, with the ability to elongate shortened telomeres, but it is only present in embryonic and tumor cells. Alternative lengthening of telomeres carries the risk of genetic change called breakage-fusion-bridge cycle. Telomeres and tumors are in the focus of scientific research, especially because of the increasing incidence in our population. Finding a cure for tumors is a competitive field for scientists, but it is difficult to achieve it without their mutual communication and collaboration.

Item Type: Thesis (Bachelor's thesis)
Supervisor: Marijanović, Inga
Date: 2012
Number of Pages: 21
Subjects: NATURAL SCIENCES > Biology
Divisions: Faculty of Science > Department of Biology
Depositing User: Silvana Šehić
Date Deposited: 10 Oct 2014 10:26
Last Modified: 10 Oct 2014 10:26
URI: http://digre.pmf.unizg.hr/id/eprint/2990

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