Homoharringtonine

Homoharringtonine (Omacetaxine mepesuccinate;HHT) is a cytotoxic alkaloid with antitumor properties which acts by inhibiting translation elongation. IC50 & Target:STAT3^[1] In Vitro:Homoharringtonine inhibits IL-6-induced STAT3 phosphorylation in a dose- and time-dependent manner. Homoharringtonine (HHT) inhibits cells growth, cell viability and colony formation, as well as induced cell apoptosis through mitochondria pathway. The cytotoxicity of Homoharringtonine on human NSCLC cell lines is investigated, A549 (wild type EGFR) and NCI-H1975 (H1975, mutant EGFR with L858R and T790M), Gefitinib is used as a control. By MTT assay, Homoharringtonine has moderate cytotoxicity to A549 with an IC₅₀ of 3.7 μM and H1975 cells are more sensitive to Homoharringtonine with an IC₅₀ of 0.7 μM. Homoharringtonine inhibits the cell proliferation and growth of A549 cells and H1975 cells in a time- and dose-dependent manner through MTT assay. By trypan blue exclusion assay, Homoharringtonine rapidly reduces viable A549 and H1975 cells in a dose- and time-dependent manner. Homoharringtonine significantly inhibits the clonogenic ability of A549 and H1975 cells^[1]. In Vivo:Homoharringtonine (10 mg/kg; 5 times weekly; 3 weeks) exhibits antitumor activity in H1975 xenograft nude mouse models^[1].
Homoharringtonine (1 mg/kg; subcutaneous injection; twice daily; 7 days) shows antitumor activity in MDA-MB-231 xenograft nude mouse models^[2].