Ar. Cole et al., Proteomic analysis of colonic crypts from normal, multiple intestinal neoplasia and p53-null mice: A comparison with colonic polyps, ELECTROPHOR, 21(9), 2000, pp. 1772-1781
In order to observe cellular changes caused by mutation of the tumor suppre
ssors, APC and p53, we have generated protein expression profiles of mouse
colon epithelial cells using two-dimensional electrophoresis (2-DE). Crypts
, polyps and stroma were isolated from normal, multiple intestinal neoplasi
a (MIN) ana p53-null mice, each with a C57Black/6J background, and subjecte
d to 2-DE in two separate pH ranges (pH 3-10 and pH 6-11). No significant d
ifferences in protein expression patterns were observed between the normal,
MIN and p53-null colon epithelial crypts. However, 64 proteins from the MI
N polyps showed a 2-fold or greater difference in intensity that was statis
tically significant as assessed by the Wilcoxon rank-sum test (p less than
or equal to 0.05). Of these, calreticulin, carbonic anhydrase I and a new m
ember of the glutathione-S-transferase theta family of proteins have so far
been identified using an in-gel digestion protocol coupled with reversed-p
hase high performance liquid chromatography (RP-HPLC) ion-trap mass spectro
metry. In addition, 38 marker proteins have been identified in a continuing
effort to generate a comprehensive 2-DE database of proteins expressed by
mouse colon epithelial cells (these databases are available at http:/www. l
udwig.edu.au/jpsl/jpSlhome.html.).