PO-168 Loss of the MCC gene expression promotes invasiveness of colon cancer cells

Abstract

IntroductionBreast cancer is the most common cancer in women in developed countries. Many reports have suggested that oestrogens play a key role in normal mammary gland development and in breast cancer progression and metastasis. About 70% of breast carcinoma expresses the oestrogen receptor alpha. The selective oestrogen receptor modulator tamoxifen, functions as an antagonist in most ER-positive breast tumours. However, 20%–30% of tumours are resistant to tamoxifen therapy. Foetal oestrogen estetrol seems to have a protective role during pregnancy and anti-estrogenic properties on breast tissue. Estetrol is an interesting compound for therapeutic applications due to its high oral bioavailability and long terminal elimination half-life, with no active oestrogen metabolites. Traditional two dimensional (2D) cell cultures lack proper environmental context leading to changes on cell function. On the contrary, three-dimensional (3D) cell culture has gained increasing interest in drug discovery due to its realistic modelling of complex environment that drives to cellular heterogeneity, nutrient and oxygen gradients of tumours. The aim of the current study was to evaluate whether estetrol have an anti-tumour activity in T47D breast cancer cells on 2D and 3D culture systems.Material and methodsT47D cells were growth in DMEM high glucose, phenol red-free media with 10% FBS. After starvation, cells were treated with increasing concentrations (1, 10, 100, 1000 nM) of Estetrol (E4), 17β-oestradiol (E2) and Tamoxifen (Tmx). All experiments were realised in DMEN with 5% of charcoal stripped FBS. Cell proliferation (trypan blue), clonogenic and wound healing micro-inserts assays were performed on 2D cell culture. T47D spheroids were performed on 96-well low attachment plate. 3D cell proliferation was measured as Feret diameter and spheroid-based migration assay was measured as radial migration index.Results and discussionsWe observed that 100 and 1000 nM of E4 significantly reduced cell proliferation, survival fraction and migration compared to the control on 2D cell model. As expected, Tmx was more effective on the reduction of cell proliferation, survival fraction and migration. On the other side, E4 and Tmx significantly reduced 3D cell proliferation and migration compared to the control. We can conclude that E4 do not stimulate cell proliferation and migration, on the contrary reduced it.ConclusionWe can conclude that E4 could have an anti-oestrogenic activity on T47D breast cancer cell line.