The mammalian transcription factor forkhead box M1 (FoxM1) is induced during G1 phase, with expression continuing through S phase and mitosis. Thiostrepton is a natural peptide thiazole antibiotic that inhibits FoxM1 in mammalian cells, preventing the expression of FoxM1-regulated genes, which includes FoxM1 itself. Through this mechanism, thiostrepton prevents proliferation and induces apoptosis in human cancer cells. These effects correlate with the ability of thiostrepton to act as a proteasome inhibitor.
Thiostrepton is a macrocyclic antibiotic incorporating thiazoles and other atypical amino acids. Patented in 1961, thiostrepton has been used as an antibiotic and acts by binding to ribosomes to prevent the binding of the EF-G elongation factor and GTP to the 50S ribosomal subunit. Thiostrepton is an inducer of tipA, a gene that controls the bacterial transcription regulators, TipAL and TipAS, that are central regulators in multidrug resistance. Thiostrepton is closely related to siomycin, a recently discovered inhibitor of oncogenic transcription factor, FoxM1.
A protein synthesis-inhibiting antibiotic
Natural antibiotic derived from Streptomyces.
ChEBI: A heterodetic cyclic peptide, in which the cyclisation step involves a formal lactonisation between the carboxy group of a quinaldic acid-based residue and a secondary alcohol. An antibiotic that inhibits bacterial protein synthesis. Also acts as an antitu
or agent.
A thiazole-containing peptide antibiotic that inhibits protein synthesis by preventing binding of GTP to 50S ribosomal subunit. Inhibits the function of elongation factor G (EF-G) and the dissociation of EF-G from the ribosome. The thiostrepton-resistant gene is also commonly used as a selective marker for recombinant DNA/plasmid technologies.
thiostrepton inhibits the transcriptional activity and foxm1 expression, and induces strong apoptosis in human cancer cells of different origin that correlates with suppression of foxm1, including leukemia, neuroblastoma, liver cancer, melanoma and prostate cancer cells. thiostrepton binds foxm1 on the promoter site to inhibit transcriptional activity of foxm1 through the foxm1 autoregulation mechanism [1].
thiostrepton suppressed tumor growth in a human breast cancer xenograft model. treatment with developed micelle-thiostrepton nanoparticles decreased xenograft tumor growth induced by the human mda-mb-231 breast and hepg2 liver cancer cell lines. these apoptosis activities in drug-treated tumors were correlated with in vivo suppression of oncogenic foxm1 [1].
1) Bowen et al. (2005), Interaction of thiostrepton and elongation factor-G with the ribosomal protein L11-binding domain; J. Biol. Chem., 280 2934
2) Gonzalez et al. (2007), Thiostrepton inhibition of tRNA delivery to the ribosome; RNA, 13 2091
3) Kwok et al. (2008), Thiostrepton selectively targets breast cancer cells through inhibition of forkhead box M1 expression; Mol. Cancer Ther., 7 2022
