Cucurbitacin I

Cucurbitacin I is triterpenoid compound that acts as a potent inhibitor of the STAT3/JAK signaling pathway. It specifically suppresses levels of tyrosine phosphorylated STAT3 in v-Src-transformed NIH 3T3 cells and in A549 cells (IC₅₀ = 500 nM) resulting in inhibition of STAT3 DNA binding and reduced STAT3-mediated gene transcription.¹ It also suppresses JAK2 phosphorylation but does not affect Src, ERK, JNK or Akt.¹ In nude mice, cucurbitacin I
(1 mg/kg/day) suppressed growth of various tumors expressing constitutively active STAT3.¹ It promotes the differentiation of dendritic cells and macrophages and enhances the effect of cancer immunotherapy.² Cucubitacin I (1 µM for 2 hours) reduced clonogenicity of nasopharyngeal carcinoma cells in vitro and suppresses tumor growth in mice (1.3 mg/kg).³

WARNING This product is not for human or veterinary use.

1. Blaskovich, M.A., Sun, J., Cantor, A., et al. Discovery of JSI-124 (Cucurbitacin I), a selective janus kinase/signal transducer and activator of transcription 3 signaling pathway inhibitor with potent antitumor activity against human and murine cancer cells in mice. Cancer Res. 63(6), 1270-1279 (2003).

2. Nefedova, Y., Nagaraj, S., Rosenbauer, A., et al. Regulation of dendritic cell differentiation and antitumor immune response in cancer by pharmacological selective inhibition of the Jak2/STAT3 pathway. Cancer Res. 65(20), 9525-9535 (2005).

3. Lui, V.W.Y., Yau, D.M.S., Wong, E.Y.L., et al. Cucurbitacin I elicits anoikis sensitization, inhibits cellular invasion and in vivo tumor formation ability of nasopharyngeal carcinoma cells. Carcinogenesis 30(12), 2085-2094 (2009).