Cell lines

MDA-MB-231 cells, 4T1 cells and Hela cells.

Preparation method

The solubility of this compound in DMSO is >10 mM. General tips for obtaining a higher concentration: Please warm the tube at 37 ℃ for 10 minutes and/or shake it in the ultrasonic bath for a while.Stock solution can be stored below -20℃ for several months.

Reaction Conditions

Five-point R428 dose titration (≤ 10 μM); Cells were preincubated with R428 for 3 h.

Applications

R428 inhibits Axl with low nanomolar activity and blocked Axl-dependent events, including Akt phosphorylation, breast cancer cell invasion, and proinflammatory cytokine production.

Animal models

Female BALB/c mice were inoculated in the mammary fat pad with 0.5 × 10⁶4T1 cells.

Dosage form

Oral dosing with R428 (7–75 mg/kg twice daily) or vehicle continued until days 19 to 21.

Applications

Oral administration of R428 displayed a dose-dependent reduction in expression of the cytokine granulocyte macrophage colony-stimulating factor and the epithelial-mesenchymal transition transcriptional regulator Snail. R428 administration reduced metastatic burden and extended survival in MDAMB-231 intracardiac and 4T1 orthotopic (median survival, >80 days compared with 52 days; P< 0.05) mouse models of breast cancer metastasis.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

R428 is a selective Axl inhibitor with an IC50 of 14 nM, more than 50-fold sensitivity for Axl than Abl, Mer, Tyro3, InsR, EGFR, HER2, and PDGFR.

Axl receptor tyrosine kinase transduces signals from extracellular matrix into cytoplasma by binding to the vitamin K-dependent protein growth arrest-specific 6 (Gas6). It is involved in several cellular processes including growth, migration, aggregation and anti-inflammation.

R428 blocks the catalytic activity of Axl, at low nanomolar concentration. [1] Axl-dependent activities, including Akt phosphorylation, cell invasion, proinflammatory cytokine production are inhibited. R428 administration reduces the expression of the cytokine granulocyte macrophage colony-stimulating factor and the epithelial-mesenchymal transition transcriptional regulator Snail. It also inhibits angiogenesis, reduces metastatic tumor burden and extends survival in animal xenograft models. In addition, R428 synergizes with cisplatin to enhance suppression of liver micrometastasis.

R428 can be administrated orally.

References:
[1]Holland SJ, Pan A, Franci C, et al. R428, a selective small molecule inhibitor of Axl kinase, blocks tumor spread and prolong survival in models of metastatic breast cancer. Cancer Res 2010. 70(4): 1544-1554.