Figure 4. Significant correlation between ERα and FOXM1 expression in human breast samples.
Expression of ERα mRNA and FOXM1 mRNA in non-cancerous breast biopsies and malignant breast epithelial tissues. RNA was isolated from epithelial cells purified from normal breast tissues and primary tumours and subjected to qRT-PCR with FOXM1, ERα and L19 primers. A) Graph shows the FOXM1 and ERα mRNA levels of the tumour samples after normalisation with L19 RNA levels. No significant correlation is seen using Pearson correlation when considering all values (n=69; Spearman r=0.198; p=0.109). Significance is defined as p<0.05. Line is linear regression, shown for illustrative purposes. B) Box and whisker plot showing the distribution of values for FOXM1. Box edges represent 25th and 75th percentiles; middle line is the median, while plus shows the mean. The whiskers represent the 10th and 90th percentiles, while outliers are shown as dots. The 75th percentile for FOXM1 mRNA values is 0.7002. C) The right-hand graph shows the FOXM1 and ERα mRNA levels of the tumour samples with FOXM1/L19 mRNA levels below the upper quartile. Correlation analysis was performed between FOXM1 and ERα mRNA. A significant and positive association was found between FOXM1 and ERα mRNA levels in breast patient samples with FOXM1 mRNA level below the upper quartile (n=52; Spearman r=0.447; p=0.0001). P < 0.05 was considered statistically significant. D) The lower left-hand graph shows the FOXM1 and ERα mRNA levels of the tumour samples with FOXM1/L19 mRNA levels in the upper quartile (0.7) of high levels of FOXM mRNA expression. No significant correlation is found using Pearson correlation (n=17; Spearman r=0.186; p=0.474). Significance is defined as p≤0.05.