Cardamonin induces G2/M arrest and apoptosis via activation of the JNK-FOXO3a pathway in breast cancer cells.
Cell Biol Int. 2019 Aug 8. Epub 2019 Aug 8. PMID: 31393045
Cardamonin (CD), a naturally occurring chalcone isolated from large black cardamom, was previously reported to suppress the proliferation of breast cancer cells. However, its precise molecular antitumor mechanisms have not been well elucidated. In this study, we found that CD markedly inhibited the proliferation of MDA-MB 231 and MCF-7 breast cancer cells through the induction of G2/M arrest and apoptosis. Reactive oxygen species (ROS) plays a pivotal role in the inhibition of CD-induced cell proliferation. Treatment with N-acetyl-cysteine (NAC), an ROS scavenger, blocked CD-induced G2/M arrest and apoptosis in this study. Quenching of ROS by overexpression of catalase also blocked CD-induced cell cycle arrest and apoptosis. We showed that CD enhanced the expression and nuclear translocation of Forkhead box O3 (FOXO3a) via upstream c-Jun N-terminal kinase, inducing the expression of FOXO3a and its target genes, including p21, p27, and Bim. This process led to the reduction of cyclin D1 and enhancement of activated caspase-3 expression. The addition of NAC markedly reversed these effects, knockdown of FOXO3a using small interfering RNA also decreased CD-induced G2/M arrest and apoptosis. In vivo, CD efficiently suppressed the growth of MDA-MB 231 breast cancer xenograft tumors. Taken together, our data provide a molecular mechanistic rationale for CD-induced cell cycle arrest and apoptosis in breast cancer cells. This article is protected by copyright. All rights reserved.