In vitro evaluation of curcumin effects on breast adenocarcinoma 2D and 3D cell cultures

Breast adenocarcinoma cell line MDA-MB-231, even if it expresses low levels of E-cadherin, still readily form multicellular aggregates of cells, namely spheroids. Curcumin is a diarylheptanoid antitumoral drug while it significantly inhibits cell migration, invasion, and colony formation in vitro and reduces tumor growth and liver metastasis in vivo. Curcumin photoactivation may enhance antiapoptotic role against cancer cells.

To evaluate the effect of low curcumin concentrations, ranged from 1.9 to 15 μM, with and without photoactivation, using a manufactured 670 nm LED-matrix. A secondary aim was to evaluate the ideal method to produce easy-to-use tumor cell spheroids, comparing two low adherence plate supports.

Breast adenocarcinoma cell line MDA-MB-231 were cultured according to 2D monolayer and 3D spheroid models then submitted to normal and photoactivated curcumin in micromolar concentrations. MTT assay was used to evaluate cell viability following curcumin application on cells. On 2D cell cultures, curcumin inhibits cell tumor development and proliferation at concentrations of 15 μM, with a viability of 65.7% at 48 hours incubation time. A decreased viability up to 25% for a concentration of 15 μM was recorded following photoactivation and cytotoxic action on breast cancer tumor cell line continued at concentrations of 7.5 and 3.75 μM. Curcumin photoactivation increases pro-apoptotic effects in both 2D and 3D tumor cell culture models and also responsiveness to curcumin is slightly reduced in spheroid-like structures. Thus, 3D tumor cell culture systems appear to be the ideal environment for in vitro assays regarding anticancer drug effects on cell viability.