Additional file 3: Figure S3. of Roles of acid-extruding ion transporters in regulation of breast cancer cell growth in a 3-dimensional microenvironment

NHE1 Ser703 phosphorylation in spheroids and 2D culture and during spheroid growth. MCF-7 and MDA-MB-231 spheroids (3D) and 2D cultures were grown 4 and 9 (MDA-MB-231 spheroids only) days in parallel, followed by lysis and Western blotting with antibodies directed against pSer703-NHE1 and total NHE1. Left and top panels in A and B, respectively, show representative Western blots, while right and lower panels, respectively, show quantifications of band intensities normalized to that of corresponding 2D or 3D culture on day 4. A: MCF-7. Note that the level of pSer703-NHE1 was normalized to the mean total NHE1 level from five other experiments (the total NHE1 data shown in Fig. 3a). Data is shown as mean + SD. 2n. B: MDA-MB-231. Data is shown as mean + SEM. 3n. A two-tailed, paired Student’s t-test was used to test for statistically significant difference in means between two groups. * indicates p < 0.05. (PDF 141 kb