Fig. 1

TSPAN8 expression is upregulated in breast CSCs. a Microarray analyses of expression of 33 members of tetraspanins family expressed in CSCs (spheres) or their corresponding non-CSCs (adherent cells) derived from three independent breast cancer patients. b Freshly isolated primary human tissues derived from two independent breast cancer patients were grown as adherent cells or spheres. Immunoblotting analyses of TSPAN8, TSPAN15 and TSPAN1 were performed. c Representative confocal images for TSPAN8 (green), ALDHA1 (red), and nuclei (blue) of adherent cells or spheres from two breast cancer patients were shown. d Quantification of the relative fluorescence intensity of TSPAN8 and ALDHA1 in spheres or adherent cells. Two-tailed Student’s t test was used for statistical analysis. ***P < 0.001, **P < 0.01, *P < 0.05. e Immunoblotting analyses of TSPAN8, NANOG, OCT4, and ALDHA1 expression in breast cancer cells from three patients were performed. TS⁻: TSPAN8-negative breast cancer cells, TS⁺: TSPAN8-positive breast cancer cells. f Flow cytometry analysis of the ratios of CD44⁺/CD24⁻ cells in TS⁺ breast cancer cells or TS⁻ breast cancer cells derived from three human breast cancer patients. g Semi-quantitative analyses of IHC staining of TSPAN8 in tissue sections of 90 breast cancer patients with different pathological molecular subtypes. ***P < 0.001, **P < 0.01, *P < 0.05 and N.S., not significant (P > 0.05) by repeated measures with Student’s t test. LuA = luminal A subtype, LuB = luminal B subtype, Her2 = Her2 amplified subtype, TNCB = triple-negative subtype. h Kaplan–Meier of survival of 90 patients with breast tumors (two groups stratified by TSPAN8 expression level. Differences between the groups were shown by a log-rank test. i–k Immunohistochemistry analyses of TSPAN8 expression in specimens of breast cancer patients with NAC-S (neo-adjuvant chemotherapy sensitive) and NAC-R (neo-adjuvant chemotherapy resistant) characteristics (scale bar = 50 μm, n = 20). l–n Immunohistochemistry analyses of TSPAN8 expression in specimens of breast cancer patients with Pre-NAC (before neo-adjuvant chemotherapy) and Post-NAC (after neo-adjuvant chemotherapy) (scale bar = 50 μm, n = 20). Note that some dots overlapped