Flavone cirsimarin impairs cell proliferation, migration, and invasion in MCF-7 cells grown in 2D and 3D models

The present study investigates the mechanisms underlying the in vitro antitumoral activity of cirsimarin (CIR 10 to 320 μM), a flavone extracted from the aerial parts of Scoparia dulcis L., on MCF-7 cells cultured in 2D and multicellular tumor spheroids (3D). CIR (from 40 μM) decreased cell viability in the resazurin assay and colony formation in the 2D model. In the same way, in the 3D model, CIR (from 40 μM) induced cell death (triple staining assay) and decreased spheroid integrity after 16 days with no induction of intracellular reactive species (CM-H2DCFDA). In 2D, CIR decreased the invasion (transwell) and horizontal migration (wound healing), while in 3D, CIR diminished cell migration (ECM® gel) and induced DNA damage (comet assay) possibly related to cell death. CIR mediated antitumoral effects in 3D spheroids by negative modulation of genes associated with cell proliferation (CCND1, CCNA2, CDK2, CDK4, and TNF) and death (BCL-XL, BAX, CASP9, and BIRC5). BIRC5 and CDKs inhibitors have been proposed as versatile anticancer drugs, which makes our results quite interesting. TNF negative modulation may also be related to the downregulation of MMP9 and MMP11 and anti-migration/invasion of MCF-7 cells cultured in 2D and 3D models. These are relevant properties for long-term strategies to avoid metastasis and improve the prognosis of breast cancer.