Research Paper Volume 11, Issue 24 pp 12295—12314

Figure 1. Expression of ERK1 and ERK2 in breast cancer. (A) Analysis of data for 50 breast cancer cell lines suggested that ERK1 mRNA was elevated in luminal breast cancer subtype when compared with basal breast cancer subtype. (B) Analysis of western blotting data from 32 breast cancer cell lines suggested that ERK1 protein expression was lower in basal breast cancer subtype when compared with luminal breast cancer subtype. (C) Analysis of western blotting data from 32 breast cancer cell lines suggested that ERK1/ERK2 protein expression ratio was lower in basal breast cancer subtype when compared with luminal breast cancer subtype. (D) Western blotting confirmed that ERK1 was highly expressed in luminal breast cancer cell lines compared with basal breast cancer cell lines tested. (E) Analysis of GSE18229 dataset for 16 normal breast tissues and 180 breast tumors suggested that ERK1 was downregulated in basal breast cancer tumors when compared with Luminal A breast cancer subtype and normal breast tissues. (F) Analysis of TCGA dataset for 519 breast tumors showed that ERK1 was downregulated in basal breast cancer tumors when compared with Luminal A breast cancer subtype and Luminal B breast cancer subtype. *, p<0.05; ***, p<0.001.