Biological Activity

Cucurbitacin I (JSI-124) is a naturally-occuring compound of cucurbitacin family that is isolated from various plant families such as Cucurbitaceae and Cruciferae. JSI-124 is a cell-permeable, potent and selective JAK/STAT3 signaling pathway inhibitor, showing markedly antitumor effects against human tumors with constitutively active STAT3 in nude mice. JSI-124 suppresses the levels of phosphotyrosine STAT3 markedly (IC₅₀= 500 nM in human lung adenocarcinoma A549) and rapidly (complete inhibition within 1-2 h), resulting in the inhibition of STAT3 DNA binding and STAT3-mediated gene transcription. JSI-124 is strongly specific for JAK/STAT3 and has no suppression against other oncogenic and tumor survival pathways such as those mediated by Akt, ERK1/2 or JNK^[1]. The selective inhibition of JAK2/STAT3 pathway by JSI-124, significantly improves DC differentiation and decreases the presence of immunosuppressive immature myeloid cells in tumor-bearing hosts, providing a useful therapeutic approach in cancer immunotherapy ^[2].

Chemical Properties

Application Concentration (Just for reference)

The appropriate working concentration of Cucurbitacin I depends on cell types, cell culture properties and specific applications. It is recommended that researchers start with optimal experiments for first use.