TY  - JOUR
A1  - Houben, Roland
A1  - Alimova, Pamela
A1  - Sarma, Bhavishya
A1  - Hesbacher, Sonja
A1  - Schulte, Carolin
A1  - Sarosi, Eva-Maria
A1  - Adam, Christian
A1  - Kervarrec, Thibault
A1  - Schrama, David
T1  - 4-[(5-methyl-1H-pyrazol-3-yl)amino]-2H-phenyl-1-phthalazinone inhibits MCPyV T antigen expression in Merkel cell carcinoma independent of Aurora kinase A
JF  - Cancers
N2  - Merkel cell carcinoma (MCC) is frequently caused by the Merkel cell polyomavirus (MCPyV), and MCPyV-positive tumor cells depend on expression of the virus-encoded T antigens (TA). Here, we identify 4-[(5-methyl-1H-pyrazol-3-yl)amino]-2H-phenyl-1-phthalazinone (PHT) — a reported inhibitor of Aurora kinase A — as a compound inhibiting growth of MCC cells by repressing noncoding control region (NCCR)-controlled TA transcription. Surprisingly, we find that TA repression is not caused by inhibition of Aurora kinase A. However, we demonstrate that β-catenin — a transcription factor repressed by active glycogen synthase kinase 3 (GSK3) — is activated by PHT, suggesting that PHT bears a hitherto unreported inhibitory activity against GSK3, a kinase known to function in promoting TA transcription. Indeed, applying an in vitro kinase assay, we demonstrate that PHT directly targets GSK3. Finally, we demonstrate that PHT exhibits in vivo antitumor activity in an MCC xenograft mouse model, suggesting a potential use in future therapeutic settings for MCC.
KW  - Merkel cell carcinoma
KW  - polyomavirus
KW  - large T antigen
KW  - phthalazinone pyrazole
KW  - glycogen synthase kinase 3
KW  - GSK3
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313547
SN  - 2072-6694
VL  - 15
IS  - 9
ER  -