[Description]:
Cilengitide is a potent and selective integrin inhibitor for αvβ3 and αvβ5 receptor, with IC50s of 4 and 79 nM, respectively.
[Related Catalog]:
[Target]
IC50: 4 and 79 nM (αvβ3 and αvβ5)[1]
[In Vitro]
Cilengitide (EMD 121974) is the αvβ3 and αvβ5 integrin receptor antagonist. In cell adhesion studies assessing the human melanoma M21 or UCLA-P3 human lung carcinoma cell lines, Cilengitide inhibits integrin-mediated binding to vitronectin with IC50s of 0.4 and 0.4 μM[1]. In vitro treatment of Cilengitide, at a concentration greater than 1 µM, shows concentration- and time-dependent cytotoxic effects. However, lower doses of Cilengitide monotherapy (0.1 and 0.5 µM) does not elicit the effective death of the both U87MG and U251MG cells. Significant cytotoxic effects are observed in the U87MG cells with the addition of 1 µM Cilengitide in combination with Belotecan monotherapy at concentration of 6.25 nM. Higher concentrations of Cilengitide (5 and 25 µM) does not significantly increase cell death in the U87MG and U251MG compare to a lower concentration of Cilengitide (1 µM)[2].
[In Vivo]
In nude mice bearing M21-L melanoma tumors, Cilengitide dose i.p. at 10, 50, and 250 μg three times per week demonstrated inhibition of tumor growth with a reduction in both tumor volume (55%, 75%, and 89%, respectively) and tumor weight (23%, 38%, and 61%, respectively), when compared to controls[2]. In the rat model studied, the systemic pharmacokinetics of i.p. Cilengitide are not affected by ILP with Cilengitide alone or ILP with Cilengitide plus Melphalan, TNF or both. Systemic Cilengitide levels reach around 20 µg/mL (approximately 35 µM) within 10 min of i.p. administration and continued to rise to approximately 40 µg/mL (approximately 70 µM) in the first hour. Thereafter Cilengitide levels in serum dropped with an elimination half-life of 2.1 hr[3].
[Cell Assay]
The cytotoxicity of the two drugs, Belotecan and Cilengitide, is measured by the Cell Counting Kit-8 (CCK-8). U87MG and U251MG cells are seeded in 96 well plates at a density of 4×103 cells per well to allow for adhesion overnight. After this, the cells are treated with Cilengitide at a concentration of 0, 0.1, 0.5, 1, 5 and 25 µM and Belotecan at a concentration of 0, 6.25, 12.5, 25, 50 and 100 nM. All possible combinations of concentrations are used to assess the combined therapeutic effect of Cilengitide and Belotecan. After 3 days, 10 µL of the CCK-8 solution is added to each well of the plate, and the plate is incubated for 3 hr in the incubator (37°C; 5% CO2). The optical density (OD) of the sample plate is measured at 450 nm in a microplate reader. The viability of tumor cells is assessed by calculating the OD ratio of the specific OD in each sample to that of the control. Each experiment is conducted in quadruplicate. The values are averaged and normalized against the controls to generate dose-response curves[2].
[Animal admin]
Mice[2] Male Balb/c-nu mice, at 8 weeks of age, are randomly assigned to four groups: control (n=10), Cilengitide (n=10), Belotecan (n=10) and combination (n=10). Cilengitide is administered intraperitoneally at a dose of 20 mg/kg daily and the Belotecan at a dose of 10 mg/kg every 4 days. The optimal dose is calculated. The control group of animals is injected with saline only. A single dose of the drugs comprised a 3-sec infusion in a volume of 3 mL/kg. The drug treatments began 7 days after the implantation of tumor cells for 16 days. Half of the animals are sacrificed 1 month after the implantation of the tumor cells for tumor volume analysis and the rest of the animals are observed for another 2 months to analyze survival. The death of the animals is defined as a weight reduction of over 25% of the initial weight or an unexpected sudden death beforehand. Rats[3] Male inbred Brown Norway rats (250 to 300 g) are injected i.p. with 50 mg/kg Cilengitide or saline 2 hr before and 3 hr after Isolated limb perfusion. The Rats are used to investigate the effects of perfusing various combinations of melphalan, TNF and cilengitide with or without the additional i.p. administration of cilengitide before and after the ILP procedure itself. The i.p. administration pre- and post-ILP is intended to optimally saturate available αVβ3 and αVβ5 integrins. Saline is used as a control in both the i.p. and perfusion settings.
[References]
[Related Small Molecules]