Cell experiment:

Human non-small-cell lung carcinoma wild type p53-containing H460 and A549, human non-small-cell lung carcinoma p53-null H1299, and human colon cancer HCT116 (p53+/+ and p53-/-) cells are used. Cells (1.5×105) are plated into 6-well plates, and incubated at 37℃ overnight. After treatment of Inauhzin and Nutlin 3 at the indicated concentrations for 48 h, cells are harvested, fixed in 70% ice-cold ethanol overnight at -20℃, resuspended in propidium iodide-solution (50 μg/mL PI, 0.1 mg/mL RNase A, 0.05% Tritin X-100 in PBS) for 40 min at 37℃, then analyzed for DNA content using a flow cytometer and proprietary software[2].

Animal experiment:

Mice[2] Five-week-old female SCID mice are used. Mice are subcutaneously inoculated with 3×106 HCT116p53+/+ cells in the right flank and tumor growth is monitored with calipers. After the mean tumor volume reaches 50-100 mm3, animals are administered Inauhzin intraperitoneally (IP), Nutlin 3 orally, or vehicles (4% DMSO for Inauhzin, EtOH: Tween: 5% Glucose=5:5:90 for Nutlin 3). Tumor volume is measured every other day, and inhibition of tumor growth (T/C) is calculated on the last day of treatment.

(±)-Nutlin-3 is a potent and selective MDM2 antagonist with IC50 value of 0.09 μM [1].

Mouse double minute 2 homolog (MDM2) is an important negative regulator of p53, a tumor suppressor. Disruption of the p53-MDM2 interaction can lead to the activation of p53 and tumor growth inhibition [1].

(±)-Nutlin-3 is a potent and selective MDM2 antagonist. In both normal and leukemic B cells, Nutlin-3 induced accumulation of p53 protein in a dose-dependent way. In B-CLL cells, Nutlin-3 also induced cell death with IC50 value of 10.4 μM and induced the transcription of p53 target genes, such as PCNA, CDKN1A/p21, GDF15, TNFRSF10B/TRAIL-R2, TP53I3/PIG3, GADD45, and DDB1 [2].

In mice bearing subcutaneous human cancer xenografts (SJSA-1), Nutlin-3 (200 mg/kg) orally treated twice a day for 20 days inhibited tumor growth by 90% [1]. In mice with established UKF-NB-3rDOX20 xenografts, Nutlin-3 (200 mg/kg) increased caspase-3 activity and induced apoptosis [3].

References:
[1].Shinohara T, Uesugi M. In-vivo activation of the p53 pathway by small-molecule antagonists of MDM2. Tanpakushitsu Kakusan Koso. 2007 Oct;52(13 Suppl):1816-7.
[2].Secchiero P, Barbarotto E, Tiribelli M, et al. Functional integrity of the p53-mediated apoptotic pathway induced by the nongenotoxic agent nutlin-3 in B-cell chronic lymphocytic leukemia (B-CLL). Blood. 2006 May 15;107(10):4122-9.
[3].Van Maerken T, Ferdinande L, Taildeman J, et al. Antitumor activity of the selective MDM2 antagonist nutlin-3 against chemoresistant neuroblastoma with wild-type p53. J Natl Cancer Inst. 2009 Nov 18;101(22):1562-74.