Induction of apoptosis and cell arrest by decursin isolated from Angelica gigas in Estrogen-independent MDA-MB-231 human breast cancer cells

Abstract

Decursin (C19H20O5; molecular weight 328), as a naturally existing coumarin compound originated from the root of Korean angelica (Angelica gigas), has been shown to possess therapeutic potential in Human prostate carcinoma cells, K562 human erythroleukemia cells, U937 myeloleukemia cells, cortical cells, in vitro and sarcoma-180 tumor cells in vivo. In the present investigation, MTT assay showed decursin (50-200 micromol/L) treatment for 72 to 120 hours strongly inhibited growth and induced apoptosis in human breast cancer MDA-MB231 cell. To confirm that decursin indeed induced apoptosis, nuclear fragmentation was quantified in cells after 4, 6-diamidino-2-phenylindole dihydrochloride (DAPI) staining. Furthermore, flow cytometry analysis indicated that decursin induced inhibition of proliferation with G1-phase arrest, which in MDA-MB231 cells was associated with inhibition of expression of cyclin D1, increased expression of the Cdk inhibitory protein p27Kip1. An increase in the pro-apoptotic protein, bax, and a reduction in the anti-apopototic protein, bcl-2, were detected in decursin treated in MDA-MB-231 cells by RT-PCR and western blot. However, the expression of Bcl-xL remained unchanged at RNA and protein in decursin-treated cells, suggesting the involvement of a mitochondrial dependent apoptotic pathway. To examine the in vivo effect of decursin in MDA-MB231, MDA-MB-231 cell was engrafted subcutaneous injection into nude mice. When tumor reached the width of 1 to 3mm, the mice were treated daily p.o. with indicated dose of decursin. Tumor growth was suppressed in the decursin-treated group compared with the vehicle-treated group as examined by t test. Taken together, these findings suggest that the anticancer effect of decursin mediated via induction of cell cycle arrest and apoptosis in human breast cancers.