Syntheses and evaluation of novel fatty acid-second-generation taxoid conjugates as promising anticancer agents
摘要:
Polyunsaturated fatty acids such as docosahexaenoic acid (DHA), linolenic acid, and linoleic acid were linked to the C-2' position of the second-generation taxoids that could overcome MDR caused by overexpressed ABC transporters. The new conjugates, tested in vivo, exhibited strong activity against drug-resistant colon cancer and drug-sensitive ovarian cancer xenografts in mice. Two of the new conjugates, DHA-SB-T-1214 and DHA-SB-T-1213, were found to achieve the total regression of drug-resistant and drug-sensitive tumors, respectively, in the animal models with substantially reduced systemic toxicity. (c) 2005 Elsevier Ltd. All rights reserved.
Syntheses and Structure−Activity Relationships of the Second-Generation Antitumor Taxoids: Exceptional Activity against Drug-Resistant Cancer Cells
摘要:
A series of new 3'-(2-methyl-1-propenyl) and 3'-(2-methylpropyl) taxoids with modifications at C-10 was synthesized by means of the beta-lactam synthon method using 10-modified 7-(triethylsilyl)-10-deacetylbaccatin III derivatives. The new taxoids thus synthesized show excellent cytotoxicity against human ovarian (A121), non-small-cell lung (A549), colon (HT-29), and breast (MCF-7) cancer cell lines. All but one of these new taxoids possess better activity than paclitaxel and docetaxel in the same assay, i.e., the IC50 values of almost all the taxoids are in the subnanomolar level. It is found that a variety of modifications at C-10 is tolerated for the activity against normal cancer cell lines, but the activity against a drug-resistant human breast cancer cell line expressing MDR phenotype (MCF7-R) is highly dependent on the structure of the C-10 modifier. A number of the new taxoids exhibit remarkable activity (IC50 = 2.1-9.1 nM) against MCF7-R. Among these, three new taxoids, SB-T-1213 (4a), SB-T-1214 (4b), and SB-T-1102 (5a), are found to be exceptionally potent, possessing 2 orders of magnitude better activity than paclitaxel and docetaxel. The observed exceptional activity of these taxoids may well be ascribed to an effective inhibition of P-glycoprotein binding by the modified C-10 moieties. The new taxoid SB-T-1213 (4a) shows an excellent activity (T/C = 0% at 12.4 and 7.7 mg/kg/dose, log(10) cell kill = 2.3 and 2.0, respectively) against B16 melanoma in B6D2F(1) mice via intravenous administration.