Figure 1. Lapatinib upregulates ERRF expression in SK-BR-3 and BT-474 breast cancer cell lines, and higher levels of ERRF correlate with lapatinib sensitivities and better patient survival.
(A) Illustration of ERRF expression after lapatinib treatment (100 nM) for 12 and 24 hours in SK-BR-3 cells based on the data from the Array Express database [43]. (B, C) Lapatinib upregulates ERRF expression in BT-474 and SK-BR-3 breast cancer cell lines, both express ERRF and respond to ERBB2 inhibition. Lapatinib treatment was at the indicated concentrations (μM) for 48 hours, and ERRF expression was measured by real-time RT-PCR. (D) Row signal of ERRF in SK-BR3 and BT-474 breast cancer cell lines and lapatinib resistant clones derived from them, as detected in a microarray study in the GEO database [44]. (E) Correlation of ERRF mRNA levels with sensitivities to ERBB2 inhibition in breast cancer cell lines, according to published information [45] and the CCLE database [58]. (F) Higher levels of ERRF expression are associated with better prognosis in ERBB2-positive breast cancer, as determined in the BreastMark database (HR = 0.5442, p = 0.028, n = 107).