Regenerative medicine is a very rapidly developing discipline. Its progress contributes to elongated
life expectancy and improved quality of life of patients suffering from so far incurable
diseases. Stem cells (SCs) are undifferentiated cells that are able to undergo unlimited number
of cell divisions and differentiation into specialized cells. Therapies based on SCs constitute
a relatively new and promising approach in regenerative medicine.
Radiotherapy is the most often used method in the treatment of cancer. In the future, the
usage of SCs will be connected with the inevitable exposure of SCs to ionizing radiation during
both treatment and diagnosis. The issue of genetic stability of SCs and cells differentiated from
them is crucial, particularly regarding the application of these cells in clinical practice. It is
important to emphasize that differentiated and undifferentiated cells possess different cell
cycle, metabolism, initial level of reactive oxygen species, DNA repair mechanisms, susceptibility
to apoptosis and frequency of mutations. All these factors contribute to the distinct
radiosensitivity of SCs and differentiated cells.
The aim of this study was to present the latest literature data concerning DNA repair mechanisms
in pluripotent SCs (Homologous Recombination, Non-homologous End Joining, Mismatch
Repair, Base Excision Repair and Nucleotide Excision Repair) in response to the influence of
cyto- and genotoxic agents, such as ionizing radiation and chemotherapeutics. Evaluation the
efficacy of DNA repair mechanisms is relevant for pluripotent SCs, because ineffective DNA
repair mechanisms may result in the accumulation of mutations and, consequently, to cancer.
Cancer Stem Cells and Radioresistance: DNA Repair and Beyond
