Ascochlorin is a prenylphenol natural product isolated from the|Ascochyta viciae|fungus that blocks the expression of MMP-9 (matrix metalloproteinase-9) by suppressing activation of the MMP-9 gene. Matrix metalloproteinases are implicated in the behavior of invading and metastatic cells, as these proteins are responsible for modification and degradation of the extracellular matrix. Ascochlorin is shown to blockade the activation of nuclear transcription factor AP-1 (activator protein-1) on the Fra-1 protein, which leads to a suppression of MMP-9 gene expression downstream. This activity is exploited against the growth of MX-1 cells (estrogen receptor-negative cancer cells), where blockade of AP-1 by Ascochlorin provides a crucial cytotoxic handle in the absence of the estrogen receptor chemotherapeutic target. Ascochlorin has also been observed to bind nuclear hormone receptors, and a library of Ascochlorin derivatives showed activity as peroxisome proliferator activated receptor gamma (PPARγ) agonists. Ascochlorin is an activator of p53.
