1.A robust luminescent assay for screening alkyladenine DNA glycosylase inhibitors to overcome DNA repair and temozolomide drug resistance
Ying-Qi SONG ; Guo-Dong LI ; Dou NIU ; Feng CHEN ; Shaozhen JING ; Vincent Kam Wai Wong ; Wanhe WANG ; Chung-Hang LEUNG
Journal of Pharmaceutical Analysis 2023;13(5):514-522
Temozolomide(TMZ)is an anticancer agent used to treat glioblastoma,typically following radiation therapy and/or surgical resection.However,despite its effectiveness,at least 50%of patients do not respond to TMZ,which is associated with repair and/or tolerance of TMZ-induced DNA lesions.Studies have demonstrated that alkyladenine DNA glycosylase(AAG),an enzyme that triggers the base excision repair(BER)pathway by excising TMZ-induced N3-methyladenine(3meA)and N7-methylguanine le-sions,is overexpressed in glioblastoma tissues compared to normal tissues.Therefore,it is essential to develop a rapid and efficient screening method for AAG inhibitors to overcome TMZ resistance in glio-blastomas.Herein,we report a robust time-resolved photoluminescence platform for identifying AAG inhibitors with improved sensitivity compared to conventional steady-state spectroscopic methods.As a proof-of-concept,this assay was used to screen 1440 food and drug administration-approved drugs against AAG,resulting in the repurposing of sunitinib as a potential AAG inhibitor.Sunitinib restored glioblastoma(GBM)cancer cell sensitivity to TMZ,inhibited GBM cell proliferation and stem cell char-acteristics,and induced GBM cell cycle arrest.Overall,this strategy offers a new method for the rapid identification of small-molecule inhibitors of BER enzyme activities that can prevent false negatives due to a fluorescent background.
2.Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models.
Anderson Chun On TSANG ; Simon Sui Man LAI ; Wai Choi CHUNG ; Abraham Yik Sau TANG ; Gilberto Ka Kit LEUNG ; Alexander Kai Kei POON ; Alfred Cheuk Hang YU ; Kwok Wing CHOW
Ultrasonography 2015;34(2):98-108
PURPOSE: The aim of this study was to validate a computational fluid dynamics (CFD) simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms. METHODS: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations. RESULTS: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography. CONCLUSION: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.
Aneurysm
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Angiography
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Computer Simulation
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Endovascular Procedures
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Hydrodynamics
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Intracranial Aneurysm*
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Stents
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Ultrasonography
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Ultrasonography, Doppler*
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Ultrasonography, Doppler, Color
3.Aurone derivatives as Vps34 inhibitors that modulate autophagy.
Guodong LI ; Joshua William BOYLE ; Chung-Nga KO ; Wu ZENG ; Vincent Kam Wai WONG ; Jian-Bo WAN ; Philip Wai Hong CHAN ; Dik-Lung MA ; Chung-Hang LEUNG
Acta Pharmaceutica Sinica B 2019;9(3):537-544
We report in this study the identification of a natural product-like antagonist () of Vps34 as a potent autophagy modulator structure-based virtual screening. Aurone derivative strongly inhibited Vps34 activity in cell-free and cell-based assays. Significantly, prevents autophagy in human cells induced either by starvation or by an mTOR inhibitor. modeling and kinetic data revealed that could function as an ATP-competitive inhibitor of Vps34. Moreover, it suppressed autophagy and without inducing heart or liver damage in mice. could be utilized as a new motif for more selective and efficacious antagonists of Vps34 for the potential treatment of autophagy-related human diseases.
4.Inhibition of the CDK9-cyclin T1 protein-protein interaction as a new approach against triple-negative breast cancer.
Sha-Sha CHENG ; Yuan-Qing QU ; Jia WU ; Guan-Jun YANG ; Hao LIU ; Wanhe WANG ; Qi HUANG ; Feng CHEN ; Guodong LI ; Chun-Yuen WONG ; Vincent Kam Wai WONG ; Dik-Lung MA ; Chung-Hang LEUNG
Acta Pharmaceutica Sinica B 2022;12(3):1390-1405
Cyclin-dependent kinase 9 (CDK9) activity is correlated with worse outcomes of triple-negative breast cancer (TNBC) patients. The heterodimer between CDK9 with cyclin T1 is essential for maintaining the active state of the kinase and targeting this protein-protein interaction (PPI) may offer promising avenues for selective CDK9 inhibition. Herein, we designed and generated a library of metal complexes bearing the 7-chloro-2-phenylquinoline CˆN ligand and tested their activity against the CDK9-cyclin T1 PPI. Complex 1 bound to CDK9 via an enthalpically-driven binding mode, leading to disruption of the CDK9-cyclin T1 interaction in vitro and in cellulo. Importantly, complex 1 showed promising anti-metastatic activity against TNBC allografts in mice and was comparably active compared to cisplatin. To our knowledge, 1 is the first CDK9-cyclin T1 PPI inhibitor with anti-metastatic activity against TNBC. Complex 1 could serve as a new platform for the future design of more efficacious kinase inhibitors against cancer, including TNBC.