Figure 1
The differential expression of GRP78 and membrane associated GRP78 (memGRP78) in parental HNSCCs and HN-CICs. (A) The whole cell proteomes of SAS cells (Cy3-labled, green) and SAS-derived sphere cells (HN-CICs) (Cy5-labeled, red) were collected and analyzed by two-dimensional differential gel electrophoresis (2-D DIGE). Image overlay of Cy3- and Cy5-labeled proteomes, red arrow indicates interests of up-regulated. (B) Total proteins were prepared from parental HNSCCs (SAS and OECM1) or HN-CICs (SAS and OECM1-derived spheres) and analyzed by immunoblotting with anti-GRP78 or anti-GAPDH antibodies as indicated. The amount of GAPDH protein of different crude cell extracts was referred as loading control. (C) memGRP78 positive cells expression in HNSCCs and HN-CICs was detected by FACS (**, p < 0.01; ***, p < 0.001). (D) The percentage of memGRP78 positive cells in isolated ALDH1+and ALDH1-HNSCCs, respectively. The co-expression profile between memGRP78 and Cripto-1 (E) or CD133 (F) in HNSCCs and HN-CICs was examined by FACS. (P: Parental HNSCCs; S: HNSCCs-isolated sphere cells).