Figure 1

MIF is overexpressed in breast cancer cells, but differs in its expression between invasive versus non-invasive cells. (a) Comparison of MIF mRNA levels in non-tumorous MCF-12A cells with the invasive MDA-MB-231 and non-invasive MDA-MB-468 and ZR-75-1 breast cancer cell lines. mRNA of non-stimulated cells was isolated, transcribed to cDNA, and MIF gene expression measured by real-time PCR. Gene expression levels are shown relative to the expression level in MCF-12A. Data are means of two determinations and are representative of two independent experiments. (b) As in (a) but comparison of MIF protein levels by Western blot. Actin was used as a loading control. (c) Quantification of Western blot by densitometry, using actin for standardization. The quantification data are means ± SD of 4 independent experiments. P values indicate statistically significant differences between MIF expression in the breast cancer cell lines compared to MCF-12A.