No abstract

A new type of inhibitor of tubulin polymerization was discovered on the basis of the combretastatin molecular skeleton. The lead compounds in this series, compounds 6 and 7, strongly inhibited tubulin polymerization in vitro and significantly arrested cells at the G(2)/M phase. Compounds 6 and 7 yielded 50- to 100-fold lower IC(50) values than did combretastatin A-4 against Colo 205, NUGC3, and HA22T human cancer cell lines as well as similar or greater growth inhibitory activities than did combretastain A-4 against DLD-1, HR, MCF-7, DU145, HONE-1, and MES-SA/DX5 human cancer cell lines. Structure-activity relationship information revealed that introduction of an amino group at the ortho position of the benzophenone ring plays an integral role for increased growth inhibition.

A series of N-heterocyclic indolyl glyoxylamides were synthesized and evaluated for in vitro and in vivo anticancer activities. They exhibited a broad spectrum of anticancer activity not only in murine leukemic cancer cells but also in human gastric, breast, and uterus cancer cells as well as their multidrug resistant sublines with a wide range of IC(50) values. They also induced apoptosis and caused DNA fragmentation in human gastric cancer cells. Among the compounds studied, 7 showed the most potent activity of growth inhibition (IC(50) = 17-1711 nM) in several human cancer cells. Given orally, compounds 7 and 13 dose-dependently prolonged the survival of animals inoculated with P388 leukemic cancer cells. N-Heterocyclic indolyl glyoxylamides may be useful as orally active chemotherapeutic agents against cancer and refractory cancerous diseases of multidrug resistance phenotype.