Fig. 1

Elevated Cx26 expression in TNBC tissue samples and in TNBC cancer stem cells. a Gene expression profiles of 20 different connexins in 2408 TNBC tissue samples were compared with those of 250 normal breast tissue samples across seven different TNBC-normal datasets using the Oncomine^TM (Compendia Bioscience, Ann Arbor, MI, USA) database (http://www.oncomine.org/). b Cell lysates from CSCs enriched from two TNBC cell lines of different subtypes and from a TNBC PDX were probed with anti-Cx26 and anti-Cx43 antibodies. The NANOG-GFP reporter was used to enrich CSCs from MDA-MB-231 (mesenchymal-like) and HCC70 (basal-like) cells, and PDX TN-1 CSCs were enriched according to ALDH activity. Actin was used as a loading control. c mRNA expression was determined by qPCR and compared between cancer stem cells (CSCs) and non-CSCs enriched from MDA-MB-231 and HCC70 cells using the NANOG-GFP reporter system and between those enriched from PDX TN-1 cells using ALDH activity sorting (ALDEFLUOR assay). Actin was used as a normalization control (*p < 0.05). All the error bars indicate standard deviation. ND, not determined