Anticancer Properties of a New Hybrid Analog AD-013 Combining a Coumarin Scaffold with an α-methylene-δ-lactone Motif

Coumarin is a natural phytochemical but as such has no medical uses. However, various natural and synthetic coumarin analogs attract attention due to their interesting biological properties.

Here, we evaluated and compared anticancer properties of a new synthetic hybrid compound AD- 013, which integrates a coumarin moiety and an α-methylene-δ-lactone motif, with novobiocin, a natural antibiotic bearing a coumarin scaffold.

Cytotoxic activities of compound AD-013 and novobiocin were assessed by the MTT assay. In order to explore the mechanism of anticancer activity of analog AD-013, we performed quantitative real-time PCR analysis of apoptosis- and cell cycle-related genes. The ability of AD-013 and novobiocin to induce apoptosis and DNA damage was studied by flow cytometry.

The cytotoxic activity of this new compound was compared with the activity of a coumarin-based antibiotic novobiocin against two cancer cell lines, MCF-7 and HL-60 and also against normal human cells, MCF- 10A and HUVEC. AD-013 was much more cytotoxic than novobiocin in both cancer cell lines and showed some selectivity against MCF-7 cancer cells as compared with MCF-10A healthy cells. Expression levels of the pro-apoptotic genes significantly increased while the anti-apoptotic genes, were down-regulated for both compounds in both cancer cell lines. AD-013 was able to inhibit cell proliferation, generate DNA damage and induce apoptosis. The obtained data showed that this compound caused the cell cycle arrest in subG0/G1 in both cancer cell lines.

The new hybrid analog was a much stronger apoptosis inducer than novobiocin and activated the intrinsic pathway of apoptosis.