Berzosertib (VE-822)

Berzosertib (VE-822) is an ATR inhibitor with a Ki value of less than 0.2 nM. It also inhibits ATM with a Ki of 34 nM.

Signaling Pathways >> Cell Cycle/DNA Damage >> ATM/ATR

Signaling Pathways >> PI3K/Akt/mTOR >> ATM/ATR

Research Areas >> Cancer

ATR:0.2 nM (Ki)

ATM:34 nM (Ki)

PI3Kγ:220 nM (Ki)

Berzosertib (VE-822) also inhibits DNK-PA, mTOR, PI3Kγ with IC50 of >4, >1, and 0.22 μM, respectively. In PSN-1 and MiaPaCa-2 cells, Berzosertib (VE-822) inhibits ATR and ATM with IC50 of 19 nM and 2.6 μM, respectively. VE-822 (80 nM) reduces phospho-Ser345-Chk1 after Gemcitabine (100 nM), radiation (XRT) (6 Gy) or both in PDAC. Additionally, Berzosertib (VE-822) does not inhibit ATM, Chk2 or DNA-PK phosphorylation in response to radiation, which further supports the selectivity of Berzosertib (VE-822) for ATR. VE-822 decreases survival of irradiated PDAC (all lines used are p53-mutant; K-Ras mutant). Knock down of Chk1 by siRNA sensitizes PSN-1 and MiaPaCa-2 cells to radiation but the radiosensitising effect is less profound compare with Berzosertib (VE-822). Adding Berzosertib (VE-822) to Gemcitabine reduces survival ~2-3-fold and dramatically more after chemoradiotherapy[1].

PSN-1 xenografts are treated with Berzosertib (VE-822) (60 mk/kg; d0, 1), Gemcitabine (100 mg/kg; d0) and/or XRT (6 Gy; d1). Tumors are then harvested 2 h post-XRT. Berzosertib (VE-822) inhibits p-Ser-345-Chk1 in xenografts after DNA-damaging agents, establishing VE-822 as a potent inhibitor of ATR in vivo. Besides, Berzosertib (VE-822) enhances the therapeutic efficacy of radiation (XRT) in MiaPaCa-2 and PSN-1 xenograft models[1].

Gemcitabine (10 nM) is added 24 h pre-XRT and is replaced with fresh medium before addition of Berzosertib (VE-822). PSN-1 cells are treated with Berzosertib (VE-822) (80 nM) for 1 h before, through to 18 h after, XRT (6 Gy). Apoptosis is analyzed 48 h after XRT by flow cytometry using an Annexin V-FITC kit with PI[1].

Mice[1] MiaPaCa-2 cells and PSN-1 cells (106 in 50 μL serum-free medium mixed with 50 μL of Matrigel) are inoculated subcutaneously in female Balb/c nude mice. When the xenograft tumors reach 80 mm3, the mice are randomized. Berzosertib (VE-822) (60 mg/kg) is administered by oral gavage on one of three alternate schedules; either daily on days 0-5 (total of six days dosing), daily on days 0 through to 3 (total of 4 days dosing) or on days 1, 3 and 5. XRT (6 Gy) is given either on days 0 or 1 or days 1-5 (total of 5 days dosing; 2 Gy). Gemcitabine is dosed at 100 mg/kg by intraperitoneal injection on day 0. XRT to the tumor is given 2 h after initiation of Berzosertib (VE-822) treatment.

[1]. Fokas E, et al. Targeting ATR in vivo using the novel inhibitor VE-822 results in selective sensitization of pancreatic tumors to radiation. Cell Death Dis. 2012 Dec 6;3:e441.

Wortmannin | Ceralasertib(AZD6738) | KU55933 (ATM Kinase Inhibitor) | VE-821 | AZD-0156 | KU 60019 | AZ20 | AZD1390 | CP-466722 | CGK 733 | ETP-46464 | KU 59403