Migracins A and B, new inhibitors of cancer cell migration, produced by Streptomyces sp.

In the course of screening for breast cancer cell migration inhibitors, we isolated two novel compounds, migracins A and B from the culture broth of Streptomyces sp. MI264-NF2. Their structures are related to those of luminacins previously isolated from Streptomyces. Migracins A and B inhibited breast cancer cell migration, monitored by wound healing assay with IC50 values of 1.31 and 1.99 μg ml(-1), respectively, in human breast carcinoma MDA-MB-231 cells without showing any cytotoxicity. Migracins also inhibited the migration of human lung adenocarcinoma A549 cells and human fibrosarcoma HT-1080 cells. Therefore, migracins may become new cancer metastasis inhibitors.