Homoharringtonine 是三尖杉中具有细胞毒性的一种生物碱，具有抗肿瘤特性。

Homoharringtonine is an alkaloid inhibitor of protein synthesis with activity in myeloid malignancies. It might have clinical activity in some patients with myelodysplastic syndrome. Homoharringtonine enhances the paracellular permeability of Caco-2 cell monolayers by modulating the protein expression and localization of claudin isoforms. Homoharringtonine has anti-Y and antileukemic activities may have the potential ability to treat acute, chronic myeloid leukemia and Gefitinib-resistant NSCLC.

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 via 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) with Gefitinib 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].

Homoharringtonine (10 mg/kg) efficiently represses tumor growth compared to vehicle control or Gefitinib (P<0.05). In addition, Homoharringtonine (HHT) treatment does not reduce the mice body weight, which suggests that Homoharringtonine has no apparent side effect. All the mice are euthanized, the tumors are isolated and imaged and the tumor sample cells are harvested to extract protein for determination if Homoharringtonine inhibits STAT3 phosphorylation via western blot. The level of STAT3 phosphorylation and MCL1 from Homoharringtonine treatment group is significantly decreased compared to vehicle control or Gefitinib treatment. Meanwhile, consistant with the results in the above, AKT1/2/3 and ERK1/2 phosphorylation is not inhibited with Homoharringtonine treatment. To further examine the STAT3 phosphorylation in the xenograft tumor samples with different treatments, the tumor samples are frozen and cutted into 10 μm sections for fluorescent immunohistochemistry. Homoharringtonine treatment inhibits STAT3 phosphorylation compared to vehicle control or Gefitinib treatment[1].

Homoharringtonine (HHT) is dissolved in PBS at a stock solution of 2.5?mM and kept at ?20°C[1]. Human NSCLC cell lines MCF-10A, A549 and H1975 cells are seeded into 96-well plate and precultured for 24?h, then treated with Homoharringtonine for 24?h or 48?h. Cell cytotoxicity is determined by MTT assay. The absorbance is measured at 570?nm by Varioskan Flash Multimode Reader, and the cell death rate is calculated. Cell viability is estimated by trypan blue dye exclusion assay. The cells which exclude the dye are viable. Place 0.5?mL of a suitable cell suspension (dilute cells in complete medium without serum to 1×106 cells per mL) following adding 0.1?mL of 0.4% trypan blue dye and mixing thoroughly, and then incubate at room temperature for 3?min and load into a hemacytometer to count cells in three separate fields (nonviable, deep blue cells as well as viable, clear cells). The cell viability rate is calculated. After staining with Hoechst 33258 at 10?mg/mL for 10?min, cell death is observed by a fluorescence microscope[1].

26833-87-4

C29H39NO9

545.629

Omacetaxine mepesuccinate;Ceflatonin;HHT;Myelostat;高三尖杉酯碱

DMSO:91 mg/mL(166.8 mM)
Chloroform, Dichloromethane, Ethyl Acetate, Acetone, etc.:Soluble
Powder: -20°C for 3 years
In solvent: -80°C for 2 years