Kinase experiment:

PARP assays are conducted in a buffer containing 50 mM Tris (pH 8.0), 1 mM DTT, 1.5 μM [3H]NAD+ (1.6 μCi/mmol), 200 nM biotinylated histone H1, 200 nM slDNA, and 1 nM PARP-1 or 4 nM PARP-2 enzyme. Reactions are terminated with 1.5 mM benzamide, transferred to streptavidin Flash plates, and counted using a TopCount microplate scintillation counter.

Animal experiment:

For B16F10 syngeneic studies, 6×104 cells are mixed with 50% Matrigel and inoculated by s.c. injection into the flank of 6- to 8-week-old female C57BL/6 mice (20 g). For cisplatin efficacy studies, female nude mice are implanted s.c. by trocar with fragments (20-30 mm3) of human tumors harvested from s.c. grown tumors in nude mice hosts. For the carboplatin and MX-1 cyclophosphamide studies, female scid mice are inoculated with 200 μL of a 1:10 dilution of tumor brei in 45% Matrigel and 45% Spinner MEM. For these established tumor studies, tumors are allowed to grow to the indicated size and then randomized to therapy groups. For DOHH-2 xenograft studies, 1×106 cells are mixed with 50% Matrigel and inoculated by s.c. injection into the flank of male scid mice. Veliparib is delivered by either oral route or continuous infusion using s.c. placement of 14-day Alzet OMP model 2002 in a vehicle containing 0.9% NaCl adjusted to pH 4.0. The OMP delivers at a rate of 12 μL daily and Veliparib doses are calculated accordingly. Temozolomide, cisplatin, carboplatin, and cyclophosphamide are formulated according to the manufacturers' recommendations.

Veliparib dihydrochloride is a potent inhibitor of PARP-1 and PARP-2 with K (i) s of 5.2 and 2.9 nmol/L, respectively [1].
PARP is short of poly ADP ribose polymerase and is reported as an overexpressed enzyme in a variety of cancers. Since it has been revealed that several forms of cancer more independent on PARP compared with regular cells, which making PARP as an attractive target for cancer therapy. Many studies have shown that PARP inhibitors act as radio- and chemotherapy- sensitizers in preclinical studies using both in vitro and in vivo models [2] [3].
Veliparib dihydrochloride is a selective inhibitor of PARP. When tested with colon cancer cell lines HCT-116 and HT-29, using veliparib dihydrochloride as an adjuvant and combing with SN38 or Oxall resulted in increasing G2/M cell cycle arrest and increased levels of DNA damage via inhibiting PARP-1 and PARP-2 [4].
In mouse model with B16F10 murine melanoma cells injected subcutaneously, oral administration of veliparib dihydrochloride with temozolomide increased the efficacy at the concentration of 3.1 mg/kg/d~25 mg/kg/d and markedly slowed tumor progression. And similar results were achieved when tested with MX-1 breast xenograft model (BRCA1 deletion and BRCA2 mutation) or HCT-116 colon carcinoma model [1].
References:
[1].    Donawho, C.K., et al., ABT-888, an orally active poly(ADP-ribose) polymerase inhibitor that potentiates DNA-damaging agents in preclinical tumor models. Clin Cancer Res, 2007. 13(9): p. 2728-37.
[2].    Benafif, S. and M. Hall, An update on PARP inhibitors for the treatment of cancer. Onco Targets Ther, 2015. 8: p. 519-28.
[3].    Guillot, C., et al., PARP inhibition and the radiosensitizing effects of the PARP inhibitor ABT-888 in in vitro hepatocellular carcinoma models. BMC Cancer, 2014. 14: p. 603.
[4].    Davidson, D., et al., The PARP inhibitor ABT-888 synergizes irinotecan treatment of colon cancer cell lines. Invest New Drugs, 2013. 31(2): p. 461-8.