Ecteinascidin 770 (ET-770) is a 1,2,3,4-tetrahydroisoquinoline alkaloid with potent anti-cancer activities; inhibits U373MG cells with an IC50 of 4.83 nM.
Ecteinascidin 770 induces apoptosis of U373MG cells. The IC50 concentration of ecteinascidin 770 for killing U373MG glioblastoma cells in culture by using the MTT assay is 4.83 nM by a 72 hour-treatment[1]. The IC50 values against human cell lines HCT116, QG56, and DU145 are 0.6, 2.4, and 0.81 nM, respectively[2]. ET-770 is shown to enhance anoikis response of human lung cancer H23 cells in a dose-dependent manner. Ecteinascidin 770 sensitizes the cells by activating the p53 protein, which in turn down-regulates anti-apoptotic myeloid cell leukemia sequence-1 (MCL1) and up-regulates BCL2-associated X protein (BAX) proteins. However, B-cell lymphoma-2 (BCL2) proteins are not significantly affected by Ecteinascidin 770. The anoikis sensitization of ET-770 is observed in H460 lung cancer cells[3].
[1]. Tabunoki H, et al. Molecular network profiling of U373MG human glioblastoma cells following induction of apoptosis by novel marine-derived anti-cancer 1,2,3,4-tetrahydroisoquinoline alkaloids. Cancer Cell Int. 2012 Apr 11;12(1):14. [2]. Saktrakulkla P, et al. Chemistry of ecteinascidins. Part 3: preparation of 2'-N-acyl derivatives of ecteinascidin 770 and evaluation of cytotoxicity. Bioorg Med Chem. 2011 Aug 1;19(15):4421-36. [3]. Powan P, et al. Ecteinascidin 770, a tetrahydroisoquinoline alkaloid, sensitizes human lung cancer cells to anoikis. Anticancer Res. 2013 Feb;33(2):505-12.