Valrubicin (N-trifluoroacetyladriamycin-14-valerate), also known as Valstar, is a chemotherapy drug from the anthracycline class. It is a semisynthetic analog of doxorubicin. Valrubicin has a more rapid uptake in the tumors than doxorubicin. Moreover, it does not have the preferential negative ion binding in cell membranes thought to be the cause for the cardiac toxicity of doxorubicin. This drug is used to treat BCG-resistant bladder carcinoma and is administered directly in the bladder (intravesical). Valrubicin affects a variety of interrelated biological functions, mostly the one involving the nucleic acid metabolism. It does DNA intercalation, then, it inhibits the incorporation of nucleosides into nucleic acids, causes extensive chromosomal damage, and arrests the cell cycle in the G2 phase. A principal mechanism of its action, mediated by valrubicin metabolites, is interference with the normal DNA breaking-resealing action of DNA topoisomerase II. This drug inhibits the DNA topoisomerase by binding to its 2-alpha part. This action cause DNA strand breaks, partial unwinding/uncoiling of DNA, and inhibition of DNA and RNA synthesis. DNA damage leads to programmed cell death (apoptosis) of the cancer cells, preventing the growth and proliferation of cancer in patients.

Valrubicin Pathway References