Dr. Tobias Bogner wiss. Mitarbeiter Room: F2-240 Phone: 0521 106 2144 E-Mail:

The cryptophycins are a family of macrocyclic depsipeptides produced as secondary metabolites by cyanobacteria of the genus Nostoc. The cryptophycins bind to tubulin which results in disturbance of microtubule dynamics. Hence, cryptophycins display a very high level of cytotoxicity even against multi drug-resistant tumor cell lines. That is why cryptophycin-52 was investigated as a cytostatic drug in clinical phase II studies. However, the studies failed due to dose-limiting neurotoxicity. Structure activity relationship (SAR) studies are performed by us to find cryptophycins with lower toxicity.

The cytotoxicity of cryptophycin-52 and its analogues are determined in cell-based cytotoxicity assays using both the non-multidrug-resistant cell line KB-3-1 and the multidrug-resistant cell line KB-V1 expressing P-glycoprotein (P-gp). The assay is based on the reduction of resazurin to fluorescent resorufin by living cells. The amount of fluorescence is proportional to the number of living cells.