PO-286 Evaluating the influence of mesenchymal stromal cells derivatives on early stage of breast cancer

Abstract

IntroductionTumour microenvironment plays a decisive role in cancer development and metastasis, and affects the therapeutic effectiveness of anticancer drugs. Mesenchymal stromal cells (MSCs) are an important elements of tumour stroma. MSCs can both stimulate and inhibit tumour progression, depending on the components of microenvironment, genesis and stage of cell differentiation. Special attention focused on the paracrine effect of products secreted by MSCs. The aim of this study was to characterise the influence of derivatives from human bone marrow MSCs on proliferation, survival, receptor profile of MCF-7 in 2D and 3D cell cultures in vitro.Material and methodsThe monolayer MCF-7 cell culture was cultured in standard conditions in DMEM nutrient medium (Sigma, USA), with 2 mM l-glutamine (Sigma, USA), 40 mg/mL Gentamicin (Biopharma, Ukraine). The initial density of MCF-7 cells was 2 × 104 cells/cm2. Human bone marrow multipotent mesenchymal stromal cells (MSCs) were used. MCF-7 cells were incubated in full nutrient conditioned media from MSCs in the ratio 1:1. For the initial generation of spheroids the DMEM nutrient medium with 2% carboxymethyl cellulose (Bio-Rad, USA) was used. Plates with spheroids were being incubated on an orbital shaker (PSU-10i, Biosan, Latvia) at 80 rpm for 3–5 hours. The spheroid culture was maintained for 7 days. Cell viability was evaluated by MTT assay. The Stemi2000 software Axio Vision Red 4.7(Zeiss, Germany) was used for processing the images. The volume of aggregates was calculated by Bjerkvig formula after 7 days of cultivation. Markers were detected by applying IHC method with primary monoclonal antibodies Ck (clone AE1/AE3, IS053, Dako, USA), vim (Clone V9, IS630, Dako, USA), EpCAM (Sigma, HPA026761, USA).Results and discussionsIncubation of tumour cells with c-medium from MSCs leaded to decreasing of cell viability by 45% and 60% after 48 and 96 hours, respectively, compared with the control samples. MSCs derivatives reduced the volume of tumour spheroids by 45% and 60% on 2nd and 4th day of cultivation respectively compared with the control. Expression of epithelial markers was increased under influence of MSCs derivatives in both 2D and 3D cell cultures, but expression of vimentin was only in 3D cell culture.ConclusionMSCs derivatives inhibited proliferative activity, reduced migration ability and increased differentiation properties of breast cancer cells in 2D and 3D cell cultures of MCF-7.