Figure 2: IRAK1 knockdown and pharmacologic inhibition impair the aggressive growth phenotypes of TNBC cells.
From: IRAK1 is a therapeutic target that drives breast cancer metastasis and resistance to paclitaxel
(a) Qantitative reverse transcriptase–PCR analysis of IRAK1 expression in a panel of breast cancer cell lines. (b) Western blot analysis of IRAK1 expression. Below shows the densitometric quantification of IRAK1 expression relative to MCF10A. (c) Western blot analysis of immnoprecipiated IRAK1 for phosphorylation (T209) in indicated TNBC cell lines. (d) Western blotting showing the knockdown efficiency of inducible shIRAK1 or nonspecific shRNA vector control treated with different concentrations of Dox. (e) Representative images of 3D Matrigel growth of indicated TNBC cells treated with or without Dox (0.5 μg ml−1) for 7 days. Scale bars, 100 μm. (f) Bar graphs showing the quantifications of primary and secondary mammosphere formation in TNBC cells treated with Dox (0.5 μg ml−1), to induce IRAK1 knockdown. (g) Scatter plot showing the MB436 and MDA231 xenograft tumour growth for 36 days in female NOD/SCID mice carrying cells’ vector control (n=6) or inducible shIRAK1 (n=6), and treated with Dox (100 mg kg−1) for 21 days. (h) Western blotting showing the effects of IRAK-inh (5 μM) on p-IRAK1 (T209) in immunoprecipitated total IRAK1. (i,j) Effects of IRAK-inh on 3D Matrigel growth and mammosphere formation. (k) Effects of IRAK1-inh (5 μM) on PDX-derived mammosphere formation. IRAK1 and p-IRAK1 (S376) IHC staining (top); mammosphere growth (bottom). Error bars represent s.e.m, n=3. *P<0.05 compared with the vector control or DMSO. NS, not significant. P-values were calculated with two-tailed t-test.
