Naslov (srp)

Uloga inhibicije protein-kinaze aktivirane adenozin-monofosfatom u indukciji apoptoze i autofagije u tumorskim ćelijskim linijama : doktorska disertacija

Autor

Vučićević, Ljubica M., 1978-

Doprinosi

Anđus, Pavle, 1958-
Harhaji-Trajković, Ljubica
Trajković, Vladimir, 1967-
Božić, Biljana, 1975-

Opis (eng)

In this doctoral dissertation the effect of intracellular energy sensor AMP-activated protein kinase (AMPK) inhibition on induction of apoptosis and autophagy in tumor cells was investigated. Pharmacological AMPK inhibitor dorsomorphin caused G2/M cell cycle block, accompanied by apoptotic cell death characterized by caspase activation, phosphatidylserine exposure and DNA fragmentation in U251 human and C6 rat glioma cells, while it had no effect on viability of primary rat astrocytes and B16 mouse melanoma cells. The mechanisms underlying the pro-apoptotic action of dorsomorphin involved induction of oxidative stress and down-regulation of antiapoptotic molecule Bcl-2. Dorsomorphin diminished AMPK phosphorylation and enzymatic activity, resulting in reduced phosphorylation of its target acetyl CoA carboxylase. AMPK activators metformin and AICAR partly prevented the cell cycle block, oxidative stress and apoptosis induced by dorsomorphin. The small interfering RNA (siRNA) targeting of human AMPK mimicked dorsomorphin-induced G2/M cell cycle arrest, but failed to induce oxidative stress and apoptosis in U251 glioma cells. Therefore, AMPK inhibition is required, but not sufficient for dorsomorphin-mediated apoptotic death of glioma cells. In this study, it was also reported that dorsomorphin can induce autophagy in cancer cells. The induction of autophagy in U251 human glioma cell line was demonstrated by acridine orange staining of intracellular acidic vesicles, Beclin 1 induction, p62 decrease and conversion of LC3-I to autophagosome-associated LC3-II in the absence and presence of proteolysis inhibitors. The presence of autophagosome like vesicles was confirmed by transmission electron microscopy. Dorsomorphin-mediated inhibition of AMPK and Raptor in U251 cells was associated with paradoxical decrease in phosphorylation of AMPK/Raptor-repressed mTOR, a major negative regulator of autophagy, and its downstream target p70S6K...

Opis (srp)

U ovoj doktorskoj disertaciji ispitivan je uticaj inhibicije intracelularnog energetskog senzora protein kinaze aktivirane adenozin-monofosfatom (AMPK) na indukciju apoptoze i autofagije u tumorskim ćelija. Farmakološki inhibitor AMPK dorzomorfin indukovao je G2/M blokadu ćelijskog ciklusa, praćen apoptozom koju karakteriše aktivacija kaspaza, eksternalizacija fosfatidilserina i fragmentacija DNK u U251 humanim i C6 pacovskim ćelijama glioma, dok na vijabilitet primarnih pacovskih astrocita i ćelija mišjeg melanoma B16 nije imao uticaja. Mehanizam indukcije apoptoze dorzomorfinom bio je posredovan stimulacijom produkcije reaktivnih vrsta kiseonika i inhibicijom ekspresije antiapoptotskog Bcl-2 proteina. Dorzomorfin je inhibirao fosforilaciju i enzimatsku aktivnost AMPK, što je za posledicu imalo smanjenje fosforilacije njenog supstrata acetil-CoA karboksilaze. Aktivatori AMPK metformin i AICAR delimično su neutralisali blokadu ćelijskog ciklusa, oksidativni stres i apoptozu indukovanu dorzomorfinom. Mala interferirajuća RNK (siRNK) koja sprečava ekspresiju humanog AMPK enzima je poput dorzomorfina zaustavila proliferaciju ćelija u G2/M fazi ćelijskog ciklusa, ali nije izazvala oksidativni stres i apoptozu u U251 ćelijama. Dakle, inhibicija AMPK je neophodna, ali ne i dovoljna za indukciju apotpoze dorzomorfinom u ćelijama glioma. U ovoj studiji takođe je pokazano da dorzomorfin indukuje autofagiju u ćelijama kancera. Indukcija autofagije u U251 ćelijama detektovana je fluorescentnim bojenjem unutarćelijskih kiselih vezikula akridin oranžom, indukcijom beklina-1, degradacijom p62 proteina i konverzijom LC3-I u formu asociranu sa autofagozomima LC3-II u odsustvu i prisustvu proteolitičkih inhibitora...

Opis (srp)

Biologija - ćelijska biologija / Biology - Cell Biology Datum odbrane : 17.12.2013

Jezik

srpski

Datum

2013

Licenca

Ovo delo je licencirano pod uslovima licence
Creative Commons CC BY-NC-ND 2.0 AT - Creative Commons Autorstvo - Nekomercijalno - Bez prerada 2.0 Austria License.

http://creativecommons.org/licenses/by-nc-nd/2.0/at/legalcode

Predmet

OSNO - Opšta sistematizacija naučnih oblasti, Karcinogeneza

glioma, dorsomorphin, AMPK, apoptosis, oxidative stress, autophagy, cancer, Akt, mTOR

OSNO - Opšta sistematizacija naučnih oblasti, Karcinogeneza

gliomi, dorzomorfin, AMPK, apoptoza, oksidativni stres, autofagija, kancer, Akt, mTOR

576