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Regulation of p53 by siRNA in radiation treated cells: Simulation studies

100%

Puszyński K., Jaksik R., Świerniak A.

International Journal of Applied Mathematics and Computer Science

2012

tom 22

nr 4

1011-1018

Ionizing radiation activates a large variety of intracellular mechanisms responsible for maintaining appropriate cell functionality or activation of apoptosis which eliminates damaged cells from the population. The mechanism of such induced cellular death is widely used in radiotherapy in order to eliminate cancer cells, although in some cases it is highly limited by increased cellular radio-resistance due to aberrations in molecular regulation mechanisms of malignant cells. Despite the positive correlation between the radiation dose and the number of apoptotic cancer cells, radiation has to be limited because of extensive side effects. Therefore, additional control signals whose role will be to maximize the cancer cells death-ratio while minimizing the radiation dose and by that the potential side effects are worth considering. In this work we present the results of simulation studies showing possibilities of single gene regulation by small interfering RNA (siRNA) that can increase radio-sensitivity of malignant cells showing aberrations in the p53 signaling pathway, responsible for DNA damage-dependant apoptosis. By blocking the production of the p53 inhibitor Mdm2, radiation treated cancer cells are pushed into the apoptotic state on a level normally achievable only with high radiation doses. The presented approach, based on a simulation study originating from experimentally validated regulatory events, concerns one of the basic problems of radiotherapy dosage limitations, which, as will be shown, can be partially avoided by using the appropriate siRNA based control mechanism.

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Single stranded-DNA detection: the role of Wip1 in ATR-dependent pathway

75%

Kurpas M., Jonak K., Puszynski K.

Mathematica Applicanda

2018

tom 46

nr 1

Obszary pojedynczonciowego DNA (ssDNA) powstaja w komórkachw wyniku ekspozycji na stres na przykład- promieniowanie UVC-lub podczas naprawy podwójnoniciowych pekniec DNA. ATR (ataxia telangiectasia mutated and Rad3-related) jest odpowiedzialne za wykrywanie ssDNA. Niedawno wykazano kluczowa role fosfatazy Wip1, która inaktywuje główne elementy szlaków odpowiedzi na uszkodzenia DNA. Opracowalismy matematyczny model sciezki ATR i połaczylismygo z modelem szlaku supresora nowotworowego p53, odpowiadajacego za aktywacje genów zaangazowanych w reakcje komórki na uszkodzenie materiału genetycznego (naprawe DNA/apoptoze). Co wiecej, dodalismy fosfataze Wip1, jako główny czynnik odpowiedzialny za wyłaczenie sciezek sygnałowych uruchamianych w ramach reakcji na uszkodzenie. Uzyskane wyniki pokazuja, ze dzieki prawidłowo dobranej dawce UVC i wyciszeniu lub zablokowaniu aktywnosci Wip1, mozliwe jest skierowanie komórek nowotworowych na szlak apoptotyczny

Single-stranded DNA (ssDNA) areas arise in cells as a result of exposure to stress agents - like UVC - or during repair of DNA double-strand breaks. ATR(ataxia telangiectasia mutated and Rad3-related) is responsible for detecting ssDNA. Recently, it has been shown that one of the most important components of cellular response to the damage is Wip1 phosphatase, which inactivates main elements of DNA damage response (DDR) pathways. We developed a mathematical model of ATR detector system, connected to p53 tumor suppressor responsible for activation of genes involved in cellular response to the damage (DNA repair/apoptosis). Moreover, we added Wip1 phosphatase, as a main agent responsible for turning o DDR. Our results show that the apoptotic threshold, where more than half of cells die, is equal to 20 J/m2. The threshold shifts when activity of the specied proteins involved in the pathway is blocked or reduced. Moreover with accurate dose of UVC and silenced or blocked Wip1, it may be possible to drive cancer cells to apoptotic pathway.

Ograniczanie wyników

1 International Journal of Applied Mathematics and Computer Science

1 Mathematica Applicanda

1 Jaksik R.

1 Jonak K.

1 Kurpas M.

1 Puszynski K.

1 Puszyński K.

1 Świerniak A.

1 2018

1 2012

Wyniki wyszukiwania

Regulation of p53 by siRNA in radiation treated cells: Simulation studies

Single stranded-DNA detection: the role of Wip1 in ATR-dependent pathway