Cell experiment:

To perform the MTT assay, cells (0.5×104/well) are plated in 96-well sterile plastic plates and allowed to attach overnight. Cells are exposed to varying doses of NPS-1034 in medium containing 1% FBS. After 72 hours, 15 μL of MTT solution (5 mg/mL) is added to each well and plates are incubated for 4 hours. Crystalline formazan is solubilized with 100 μL of a 10% (w/v) SDS solution for 24 hours. Absorbance at 595 nm is read spectrophotometrically using a microplate reader[1].

Animal experiment:

Female severe combined immunodeficiency (SCID) mice (17 to 20 g, 6 weeks of age) are used. Tumors are grown by implanting 5×106 cells in Matrigel into the mouse flanks. Treatment of 5 mice per group is started when the tumors have reached a volume of 50 to 100 mm3 with vehicle control or NPS-1034 (10 mg/kg, 5 days a week). NPS-1034 is administered orally. Treatment is stopped at the indicated day and mice are followed-up for tumor recurrence. To measure tumor size, the length (L) and width (W) of the tumor are measured with calipers, and tumor volume (TV) is calculated as TV=(L×W2)/2. Immunohistochemical staining is performed using a specific primary antibody, the EnVision Plus staining kit, and the APO-Direct terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay kit, according to the suppliers' instructions. Quantitative analysis of section staining is performed by counting immunopositive cells in 5 arbitrarily selected fields at ×40 magnification[1].

NPS-1034 is a MET inhibitor with IC50 of 4 nmol/L [1].

The hepatocyte growth factor receptor tyrosine kinase MET is required for various morphogenetic events and controls the malignant progression of many human tumors. In various advanced human cancer, gene amplification can deregulate MET [1].

In MKN45 and SNU638 cell lines highly expressing the MET gene and p-MET (phosphorylated MET), IC50 values of NPS-1034 to inhibit cell viability were 112.7 and 190.3 nmol, respectively. In AGS, KATOIII, NCI-N87, MKN1, MKN28, and MKN74 cells, the IC50 values of NPS-1034 to inhibit cell viability ranged from 1 μmol to more than 10 μmol. In MKN45 cells, treatment with NPS-1034 dramatically decreased MET phosphorylation (activation). But in MKN28 cells, MET phosphorylation was not dramatically decreased. This meant that the anti-proliferative effect of NPS-1034 was resulted from its inhibition of p-MET [1].

In nude mice bearing MKN45 tumors, after the diameter of MKN45 tumors had reached about 180 mm3, NPS-1034 at a dose of 30 mg/kg or PBS as vehicle was orally administered once daily for 25 days. It was found that NPS-1034 inhibited the proliferation of tumors highly expressing p-MET. Without drug treatment, neovascularization appeared in tumors in nude mice when the tumor volume was >150 mm3. NPS-1034 treatment clearly decreased the vascularization of the tumors in nude mice [1].

Reference:
[1].  Shin JS, Hong SW, Moon JH, et al. NPS-1034, a novel MET inhibitor, inhibits the activated MET receptor and its constitutively active mutants. Investigational new drugs, 2014, 32(3): 389-399.