Figure 7. The panel of TNBC cell lines does not express the IL-6 receptor α.

(Left Panel) MDA-MB-231, Hs578T and MDA-MB-468 cells were tested alongside THP-1 cells (as a positive control) for the presence of IL-6Rα mRNA expression via QRT-PCR. Significant message was observed in THP-1 cells while little, if any, message was observed in the panel of TNBC cell lines. Results are expressed relative to THP-1 cells and represent three separate experiments. (Right Panels) MDA-MB-231, Hs578T and MDA-MB-468 cells (upper 3 panels) and THP-1 cells (lowest panel) were tested for membrane expression of IL-6Rα and gp130 using flow cytometric analysis. The panel of TNBC cell lines treated with a mAb to IL-6Rα exhibit nearly identical fluorescence (solid grey line) as cells treated with an isotype control (dotted line) suggesting that no IL-6Rα is present on the TNBC cell lines. In contrast, THP-1 cells treated with a mAb to IL-6Rα show a definite shift in fluorescence (solid grey line) compared to THP-1 cells treated with an isotype control (dotted line) demonstrating that THP-1 cells express IL-6Rα, consistent with the literature (Vermes et al., 2002), and that the mAb for IL-6Rα works as expected. All three TNBC cell lines were positive for gp130 (solid black line) consistent with the results from the QRT-PCR (Table 1). Results representative of three separate experiments.