Identification of galiellalactone-based novel STAT3-selective inhibitors with cytotoxic activities against triple-negative breast cancer cell lines

Publication date: 1 October 2017
Source:Bioorganic & Medicinal Chemistry, Volume 25, Issue 19
Author(s): Hyun Su Kim, Taewoo Kim, Hyejin Ko, Jeeyeon Lee, Yeong Shik Kim, Young-Ger Suh
Signal transducer and activator of transcription 3 (STAT3) is phosphorylated in breast cancer cells, particularly triple-negative breast cancers (TNBCs). Therefore, the inhibition of constitutive phosphorylated STAT3 is a promising therapeutic for TNBC treatment. Recently, a series of novel STAT3 inhibitors based on natural (−)-galiellalactone have been identified to inhibit STAT3 phosphorylation at the Tyr705 residue. Interestingly, the truncation of the cyclohexene moiety of (−)-galiellalactone to [3.3] bicyclic lactone as a pharmacophoric core produced improved cytotoxic effects against TNBCs. The potent analogues 16 and 17, identified from a STAT3-mediated luciferase reporter assay, selectively inhibited the STAT3 signaling pathway without affecting STAT1 or STAT5.

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