An Effect of Culture Media on Epithelial Differentiation Markers in Breast Cancer Cell Lines MCF7, MDA-MB-436 and SkBr3

Abstract

Background and objectives: Cell culture is one of the mainstays in the research of breast cancer biology, although the extent to which this approach allows to preserve the original characteristics of originating tumor and implications of cell culture findings to real life situations have been widely debated in the literature. The aim of this study was to determine the role of three cell culture media on transcriptional expression of breast cancer markers in three breast cancer reference cell lines (MCF7, SkBr3 and MDA-MB-436). Materials and methods: Cell lines were conditioned in three studied media (all containing 5% fetal bovine serum (FBS) + hormones/growth factors; different composition of basal media) for four passages. Population growth was characterized by cumulative population doubling levels, average generation time, cell yield and viability at the fourth passage. Transcriptional expression of breast cancer differentiation markers and regulatory transcriptional programs was measured by qPCR. Results: Differences in the composition of growth media significantly influenced the growth of studied cell lines and the expression of mammary lineage governing transcriptional programs and luminal/basal markers. Effects of media on transcriptional expression were more pronounced in luminal cell lines (MCF7, SkBr3), than in the basal cell line (MDA-MB-436). Changes in growth media in terms of supplementation and basal medium delayed growth of cells, but improved cell yields. Conclusions: The expression of breast cancer cell differentiation phenotypic markers depends on the composition of cell growth medium, therefore cell culture as a tool in phenotypic studies should be used considering this effect. The findings of such studies should always be interpreted with caution. The formulation of cell growth media has greater effect on the expression of phenotypic markers in luminal, rather than basal cell lines. Media containing mitogens and higher vitamin content improved efficacy of cell culture in terms of cell yields, although greatly increased growth times.

Keywords: breast cancer cell line; culture media; cultured/substance effects; gene expression profiling; tumor cells.

Figure 1

Growth and proliferation of MCF7 (n = 5 in each medium), MDA-MB-436 (n = 3 in A10 + I + Ct, n = 4 in the studied media) and SkBr3 (n = 3 in each medium) cell lines in A10, A5, D5 and R5 media during fourth subculture. (A) Cumulative population doubling levels in studied media until the end of the fourth passage. (B) Cell population generation time. (C) The viability of cells after trypsinization of the subculture. (D) Cell yields at the end of the subculture.

Figure 2

Morphological appearance of MCF7 cells in phase-contrast microscopy on Day 6 of the fourth subculture in A10 (A), A5 (B), D5 (C) and R5 (D) media, 100× magnification.

Figure 3

Morphological appearance of MDA-MB-436 cells in phase-contrast microscopy on Day 8 of the fourth subculture in A10 + I + Ct (A), A5 (B), D5 (C) and R5 (D) media, 100× magnification.

Figure 4

Morphological appearance of SkBr3 cells in phase-contrast microscopy on Day 15 of the fourth subculture in A10 (A), A5 (B), D5 (C) and R5 (D) media, 100× magnification.

Figure 5

Hierarchical clustering of the differential expression profiles of MCF7, SkBr3 and MDA-MB-436 cell lines across all studied media; here ddCt values are shown in comparison to A10 medium.