Figure 1. Genome-wide Expression Profiling Identifies Rab2A as a Pin1 Target that Promotes BCSC Expansion and EMT.

(A) Hierarchical cluster of the microarray data of the Lin⁻ population of mammary epithelial cells in two pairs of WT and Pin1 KO littermates.

(B) Genomic profiling identified 14 potential target genes that were downregulated in Pin1 KO MECs and neuron cells (NCs) but upregulated in mouse MaSCs or BCSCs.

(C) Heatmap depicting the fold changes of 14 candidate genes, which were downregulated in Pin1 KO cells (presented by KO/WT ratio) but upregulated in either mouse MaSCs or BCSCs (presented by SC/non-SC ratio).

(D) Pin1 KD reduced Rab2A mRNA in human breast cancer lines, as assayed by real-time PCR.

(E and F) Pin1 activated the Rab2A promoter in a dose-dependent manner.

(G–I) Both Pin1 and c-Jun bound to the Rab2A promoter, as shown by ChIP and Re-ChIP analyses. Real-time PCR data were calibrated to immunoglobulin G (IgG) control and normalized with sample inputs of chromatin harvested prior to immunoprecipitation.

(J) Rab2A was knocked down in vector control and Pin1-overexpressing HMLE cells, as confirmed by immunoblot.

(K and L) Rab2A KD in HMLE cells reduced the CD24⁻CD44⁺ population and suppressed the ability of Pin1 overexpression to increase the CD24⁻CD44⁺ population.

(M) Rab2A KD in HMLE cells reduced mammosphere-forming activity and impaired the ability of Pin1 overexpression to increase mammosphere-forming activity.

(N and O) Rab2A KD impaired the ability of Pin1 overexpression to induce the EMT in HMLE cells, as shown by cell morphology (N) or upregulation of E-cadherin and downregulation of N-cadherin, fibronectin, and vimentin by qRT-PCR (O). Scale bar represents 100 μm.

In all panels, error bars represent SD of three independent experiments. See also Figures S1 and S2.