The Wee1 inhibitor MK1775 (AZD1775) is currently being tested in clinical trials for cancer treatment. Here, we show that the p53 target and CDK inhibitor p21 protects against MK1775-induced DNA damage during S-phase. Cancer and normal cells deficient for p21 (HCT116 p21-/-, RPE p21-/-, and U2OS transfected with p21 siRNA) showed higher induction of the DNA damage marker γH2AX in S-phase in response to MK1775 compared to the respective parental cells. Furthermore, upon MK1775 treatment the levels of phospho-DNA PKcs S2056 and phospho-RPA S4/S8 were higher in the p21 deficient cells, consistent with increased DNA breakage. Cell cycle analysis revealed that these effects were due to an S-phase function of p21, but MK1775-induced S-phase CDK activity was not altered as measured by CDK-dependent phosphorylations. In the p21 deficient cancer cells MK1775-induced cell death was also increased. Moreover, p21 deficiency sensitized to combined treatment of MK1775 and the CHK1-inhibitor AZD6772, and to the combination of MK1775 with ionizing radiation. These results show that p21 protects cancer cells against Wee1 inhibition and suggest that S-phase functions of p21 contribute to mediate such protection. As p21 can be epigenetically downregulated in human cancer, we propose that p21 levels may be considered during future applications of Wee1 inhibitors.

b Department of Cancer Cell Biology Institute of Molecular Genetics of the ASCR Prague Czech Republic

Department of Radiation Biology Institute for Cancer Research Norwegian Radium Hospital Oslo University Hospital Oslo Norway

000      

00000naa a2200000 a 4500

001      

bmc20022795

003      

CZ-PrNML

005      

20201214124820.0

007      

ta

008      

201125s2019 xxu f 000 0|eng||

009      

AR

024    7_

$a 10.1080/15384101.2019.1593649 $2 doi

035    __

$a (PubMed)30943845

040    __

$a ABA008 $b cze $d ABA008 $e AACR2

041    0_

$a eng

044    __

$a xxu

100    1_

$a Hauge, Sissel $u a Department of Radiation Biology , Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital , Oslo , Norway.

245    10

$a p21 limits S phase DNA damage caused by the Wee1 inhibitor MK1775 / $c S. Hauge, L. Macurek, RG. Syljuåsen,

520    9_

$a The Wee1 inhibitor MK1775 (AZD1775) is currently being tested in clinical trials for cancer treatment. Here, we show that the p53 target and CDK inhibitor p21 protects against MK1775-induced DNA damage during S-phase. Cancer and normal cells deficient for p21 (HCT116 p21-/-, RPE p21-/-, and U2OS transfected with p21 siRNA) showed higher induction of the DNA damage marker γH2AX in S-phase in response to MK1775 compared to the respective parental cells. Furthermore, upon MK1775 treatment the levels of phospho-DNA PKcs S2056 and phospho-RPA S4/S8 were higher in the p21 deficient cells, consistent with increased DNA breakage. Cell cycle analysis revealed that these effects were due to an S-phase function of p21, but MK1775-induced S-phase CDK activity was not altered as measured by CDK-dependent phosphorylations. In the p21 deficient cancer cells MK1775-induced cell death was also increased. Moreover, p21 deficiency sensitized to combined treatment of MK1775 and the CHK1-inhibitor AZD6772, and to the combination of MK1775 with ionizing radiation. These results show that p21 protects cancer cells against Wee1 inhibition and suggest that S-phase functions of p21 contribute to mediate such protection. As p21 can be epigenetically downregulated in human cancer, we propose that p21 levels may be considered during future applications of Wee1 inhibitors.

650    _2

$a antitumorózní látky $x farmakologie $x terapeutické užití $7 D000970

650    _2

$a proteiny buněčného cyklu $x antagonisté a inhibitory $7 D018797

650    _2

$a viabilita buněk $x účinky léků $x genetika $x účinky záření $7 D002470

650    _2

$a checkpoint kinasa 1 $x antagonisté a inhibitory $7 D000071877

650    _2

$a inhibitor p21 cyklin-dependentní kinasy $x genetika $x metabolismus $7 D050759

650    _2

$a cyklin-dependentní kinasy $x antagonisté a inhibitory $x metabolismus $7 D018844

650    _2

$a poškození DNA $x účinky léků $x genetika $7 D004249

650    _2

$a HCT116 buňky $7 D045325

650    _2

$a lidé $7 D006801

650    _2

$a nádory $x farmakoterapie $x metabolismus $7 D009369

650    _2

$a fosforylace $x účinky léků $7 D010766

650    _2

$a tyrosinkinasy $x antagonisté a inhibitory $7 D011505

650    _2

$a pyrazoly $x farmakologie $x terapeutické užití $7 D011720

650    _2

$a pyrimidinony $x farmakologie $x terapeutické užití $7 D011744

650    _2

$a malá interferující RNA $x genetika $7 D034741

650    _2

$a kontrolní body fáze S buněčného cyklu $x účinky léků $7 D059807

650    _2

$a transfekce $7 D014162

655    _2

$a časopisecké články $7 D016428

655    _2

$a práce podpořená grantem $7 D013485

700    1_

$a Macurek, Libor $u b Department of Cancer Cell Biology , Institute of Molecular Genetics of the ASCR , Prague , Czech Republic.

700    1_

$a Syljuåsen, Randi G $u a Department of Radiation Biology , Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital , Oslo , Norway.

773    0_

$w MED00173232 $t Cell cycle (Georgetown, Tex.) $x 1551-4005 $g Roč. 18, č. 8 (2019), s. 834-847

856    41

$u https://pubmed.ncbi.nlm.nih.gov/30943845 $y Pubmed

910    __

$a ABA008 $b sig $c sign $y a $z 0

990    __

$a 20201125 $b ABA008

991    __

$a 20201214124820 $b ABA008

999    __

$a ok $b bmc $g 1595114 $s 1113471

BAS    __

$a 3

BAS    __

$a PreBMC

BMC    __

$a 2019 $b 18 $c 8 $d 834-847 $e 20190403 $i 1551-4005 $m Cell Cycle $n Cell Cycle $x MED00173232

LZP    __

$a Pubmed-20201125