Fig. 1

Expression of AQP3, 4 and 5 proteins in intestinal and diffuse types of human gastric adenocarcinomas. a, b Western blotting for detecting proteins of AQP5 (27 kDa), AQP3 (31 kDa) and AQP4 (34 kDa) in paired normal mucosa (N) and adenocarcinoma (T). Typical example of intestinal type of adenocarcinoma (a; patient No. 4 in Table 1) and diffuse type of adenocarcinoma (b; patient No. 10 in Table 1) are shown. As a loading control, expression level of β-actin (42 kDa) was tested. Membrane fraction of rat kidney was used as a positive control for AQP3 (cont in a and b) and membrane fraction of intestinal type of human gastric adenocarcinoma (No. 6 in Table 1) as a positive control for AQP5 (cont in b). c The specificity of bands of 27 kDa (AQP5), 31 kDa (AQP3) and 34 kDa (AQP4) was confirmed by using the corresponding blocking peptides (BP). d, e The level of protein expression of AQP5 (d) and AQP4 (e) in intestinal and diffuse types of adenocarcinomas was compared with that of paired normal mucosa. The score for the normalized expression level of AQP5 or AQP4 = [(amount of AQP5 or AQP4 protein in the adenocarcinoma)/(amount of β-actin protein in the adenocarcinoma)]/[(amount of AQP5 or AQP4 protein in the normal mucosa)/(amount of β-actin protein in the normal mucosa)]. The score for normal mucosa was normalized as 1. Averaged score ± SE of the intestinal and diffuse types of adenocarcinomas are shown. n = 10. **p < 0.01. NS not significant (p > 0.05)