Fig. 3
Slk deletion increases phosphorylated Sox9 which is correlated with higher Sox10 expression in human breast cancer samples. a Activity of Sox9 was assessed by Western blot analysis using a pS181-specific antibody in SLKfl/fl and SLK-/- NDL cells. Active AKT was assessed using a pS473 antibody. b pSox9 S181 histochemistry was performed on hyperplastic lesions from mammary glands of SLK+/+ and SLKfl/fl NIC mice (n=10 glands/genotype) and representative images are shown for each genotype. Quantitation showed that SLK-null hyperplasia have a two-fold increase in pSox9 S181-positive nuclei (18 ± 4% vs 35 ± 7%; p<0.05). Scale bar = 100 μm. c The TCGA dataset was interrogated for expression of SOX9 and SOX10 across all breast cancer subtypes. Co-expression of both genes was observed in these patient samples with a Pearson correlation coefficient of 0.351 for all subtypes combined. d Serial sections of a human breast cancer TMA, BR20810, containing 104 breast cancer cases were stained with pSox9 S181 and Sox10 antibodies. Representative cores from each major molecular subtype, as defined by staining intensity of HER2, ESR1, and PGR, are shown. Scale bar = 200 μm