SKU: S083  / 
    CAS Number: 12656-09-6

    Siomycin A

    R$2,184.00 - R$7,620.48

    Siomycin is a macrocyclic thiopeptide antibiotic with potent and selective antibacterial activity first isolated from the fermentation product of Streptomyces sioyaensis by Nishimura in 1959. This member of the thiostrepton family is a potent inhibitor of the oncogenic transcription factor, FoxM1.   In vitro, siomycin inhibits FoxM1-induced cell growth on soft agar and selectively kills transformed cells.  Siomycin has anti-cancer properties.

    Siomycin is soluble in DMF and DMSO.

    Molecular Formula C71H81N19O18S5
    Mechanism of Action Siomycin inhibits protein synthesis in bacteria by interfering with rRNA binding, specifically the 23S rRNA. The reduction in transcription activity is reflected in the down-regulation of protein and mRNA levels of the transcription factor Forkhead box family ( FoxM1) and effects on downstream genes, Cdc25B, survivin and CENPB.
    Cancer Research Applications

    The antitumor effects of Siomycin A in vitro was studied and was shown to inhibit proliferative ability a variety of human tumor cell lines. it also affected the cytoskeleton of tumor cells by downregulating the expression of a-tubulin protein (ref). Cell viabilitly was reduced with increased Siomycin concentration, for a dose-dependent effect (Wang et al, 2019).

    Siomycin A induces reactive oxygen species-mediated cytotoxicity in ovarian cancer cells PA1 and OVCAR3 and inhibited proliferation of ovarian cancer cells (Shao et al, 2020).

    FOXM1 is a key transcription factor regulating oncogenic signaling pathways in meningioma (Kim et al, 2020).


    Ebata M et al (1969) Studies on Siomycin. I Physicochemical properties of Siomycin A, B and C. J. Antibiot Ser. A, 22:364

    Kim H et al (2020) Forkhead box M1 (FOXM1) transcription factor is a key oncogenic driver of aggressive human meningioma progression. Neuropathol Appl. Neurobiol. 46(2):125-141

    Miyazaki K, Ebata M and Otsuka H (1969) Studies on Siomycin III. J. Antibiotics 22(9):434-441 PMID 4899606

    Radhakrishnan et al (2006) Identification of a chemical inhibitor of the oncogenic transcription factor Forkhead Box M1. Cancer Res. 19: 9731

    Shao X, Zhang F, Gao X, Xu F (2021) Siomycin A induces reactive oxygen species-mediated cytotoxicity in ovarian cancer cells. Oncol Lett.;21(6):431 PMID 33868469

    Wang B, Wang W, Meng HY, Chen J, Yuan LJ (2019) Effects and mechanism of Siomycin A on the growth and apoptosis of MiaPaCa-2 cancer cells. Oncol Lett. 18(3):2869-2876 PMID 31452766