Figure 1.

Expression of Core Circadian Genes Is Altered in BC

(A) The 1,097 BC patient samples from the TCGA database were analyzed via unsupervised hierarchical clustering to show circadian expression profiles among the PAM50 subtypes: Basal-like, HER2-enriched, Luminal A, Luminal B, and Normal-like.

(B and C) The patient samples were analyzed for average expression of circadian genes (B) and ARNTL expression (C), grouped by BC subtypes.

(D) Immunoblot analysis (left panel) of markers of active insulin signaling—phosphorylated AKT and phosphorylated IRβ—were examined to reflect relative levels of insulin signaling. GAPDH serves as a loading control. Quantification of phosphorylated AKT/total AKT and phosphorylated IRβ/total IRβ is shown relative to GAPDH levels, and signal in untreated cells is set to 1 (right panel). CIT: chronic insulin treatment.

(E) Cells were entrained by serum shock. Total RNA was collected every 4 h and analyzed by qRT-PCR. Data are shown as mean ± SD; n = 3; one-way ANOVA with Tukey's post hoc test. The GAPDH mRNA level of untreated cells at 0 h is set to 1.

(B, C, and E) N/S p > 0.05; *p > 0.05; **p < 0.05; ***p < 0.001. See also Figures S1 and S2.