Cancer Lett 2012 Dec 4;325(2):165-74. Epub 2012 Jul 4.
Miltenyi Biotec GmbH, Bergisch Gladbach, Germany.
We performed next generation sequencing- and microarray-based gene expression profiling of CD44(+)/CD24(-)/CD45(-) breast CSCs (cancer stem cells) isolated from primary ERα-positive breast cancer. By combining semi-automated dissociation of human tumor tissue, magnetic cell sorting and cDNA amplification less than 500 CSCs were required for transcriptome analyses. Besides overexpressing genes involved in maintenance of stemness, the CSCs showed higher levels of genes that drive the PI3K pathway, including EGFR, HB-EGF, PDGFRA/B, PDGF, MET, PIK3CA, PIK3R1 and PIK3R2. This suggests that, in CSCs of ERα-positive breast cancer, the PI3K pathway which is involved in endocrine resistance is hyperactive.