AbstractRecent evidence assigns integrins and metalloproteinases (MMPs) an important role in regulating tumor cell progression. Here, we demonstrate that 3‐O‐methylfunicone (OMF), a secondary metabolite produced by Penicillium pinophilum, affects cell proliferation and motility of breast cancer MCF‐7 cells, downregulating αvβ5 integrin, and inhibiting MMP‐9 secretion. This effect was absent when the non‐tumoral MCF‐10 cell line was used. Inhibition of cell motility was also associated to modifications in cell shape and in the distribution of tubulin fibers of OMF‐treated MCF‐7 cells. In addition, a possible effect on survivin and hTERT was also investigated. We found that OMF strongly inhibits survivin and hTERT gene expression. The results of this study indicate that OMF‐induced inhibition of cell motility may be mediated through the modulation of αvβ5 integrin and MMP‐9 secretion. In addition, the inhibition of typical markers of tumor progression such as hTERT and survivin in MCF‐7 and their inactivity towards MCF10 provide strong evidence for a potential use of OMF in anticancer therapy. © 2007 Wiley‐Liss, Inc.