Improved therapeutic responses for liposomal doxorubicin targeted via thrombospondin peptidomimetics versus untargeted doxorubicin.

New therapies in cancer treatment are focusing on multifaceted approaches to starve and kill tumors utilizing both antiangiogenic and chemotherapeutic compounds. In this work, we searched for a peptide vector that would home liposomes both to endothelial and tumor cells. [Abu6]TSPB and [Abu6]TSPA, aspartimide analogs of natural sequences of TSP-1 and TSP-2, respectively, were tested for adhesion of tumor and endothelial cells, in vivo and in vitro antiangiogenic effects, and in vivo antitumor action.

In vitro effects of SIKVAV retro and retro-enantio analogues on tumor metastatic events.

The SIKVAV peptide, located on the long arm of the laminin alpha1 chain, promotes cell adhesion, invasion and migration of tumor and endothelial cells, resulting in tumor growth, angiogenesis and metastasis. In this paper, we report the synthesis of the SIKVAV peptide and its retro (reverse l-amino acid order) and retro-enantio (reverse d-amino acid order) analogues and their effect on three critical steps in the metastatic process: cell-extracellular matrix protein (ECM) adhesion, cell migration and homotypic cell adhesion, using B16F10 melanoma cells. Results show that all peptides compete with laminin-1 cell attachment, but only SIKVAV induces peptide-cell adhesion.

Synthesis of a series of 3-cyanopropionamides and 4-imino-gamma-butyrolactams and evaluation of their function as modulators of multidrug resistance.

The synthesis of the 3-cyanopropionamides 3a and 3b, of the 2,2-dimethyl-3-cyanopropionamides 4a-4c and of the 4-imino-gamma-butyrolactams 5a and 5b (cyclic functional isomers of 3-cyanopropionamides) is described. The amides 3a and 3b were obtained by aminolysis of the corresponding acid chlorides, which are accessible via hydrolysis of the ethyl esters to the acids. This methodology was not used for the synthesis of the amides 4a-4c owing to steric hindrance to hydrolysis in the corresponding ethyl esters.

Sensitizing properties of new N-(2-arylalkyl) propionamides in drug-sensitive and multidrug-resistant tumor cells.

The propionamides 5 and 6 have been synthesized and tested for stimulation of antitumor drug activity. 5 and 6b increase vincristine cytotoxicity in drug-sensitive murine tumor cells; 5 also increases the toxicity in multidrug resistant cells. Dissimilar trends in sensitive and resistant cells have been observed for the stimulating activity of several propionamides of this family and structurally related verapamil with their molar refractivity, suggesting different size requirements for the sensitizers in sensitive and resistant cells.