Immunolocalization of protein 4.1B/DAL-1 during neoplastic transformation of mouse and human intestinal epithelium.
Recently, we have reported that the protein 4.1B immunolocalization occurred only in matured columnar epithelial cells of normal rat intestines. This finding suggested that protein 4.1B expression could be examined for a possible change during neoplastic transformation of the intestinal mucosa. In the present study, we first present the distribution of mouse protein 4.1B in normal intestinal epithelial cells and tumor cells using the adenomatous polyposis coli (Apc) mutant mouse model. A low level of protein 4.1B expression coincided with the phenotypic transition to carcinoma. To examine the protein 4.1B expression in human intestinal mucosa, we used another antibody against an isoform of the human protein 4.1B, DAL-1 (differentially expressed adenocarcinoma of the lung). Human DAL-1 was also expressed in matured epithelial cells in human colons, with a definite expression gradient along the crypt axis. In human colorectal cancer cells, however, DAL-1 expression was not detected. These results suggest that mouse protein 4.1B and human DAL-1 might have a striking analogy of functions, which may be integrally involved in epithelial proliferation. We propose that loss of protein 4.1B/DAL-1 expression might be a marker of intestinal tumors, indicative of a tumor suppressor function in the intestinal mucosa.
Ohno
Nobuhiko
N
Department of Anatomy, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Tamaho, 409-3898 Yamanashi, Japan. sohno@yamanashi.ac.jp
Terada
Nobuo
N
Murata
Shin-ichi
S
Yamakawa
Hisashi
H
Newsham
Irene F
IF
Katoh
Ryohei
R
Ohara
Osamu
O
Ohno
Shinichi
S
D000818:Animals; D015153:Blotting, Western; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D003106:Colon / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000737:chemistry; D003598:Cytoskeletal Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007413:Intestinal Mucosa / Q000378:metabolism*; D007414:Intestinal Neoplasms / Q000737:chemistry; D008565:Membrane Proteins / Q000032:analysis*; D051379:Mice; D008840:Microfilament Proteins; D015534:Trans-Activators / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000032:analysis*; D051176:beta Catenin
C495270:CTNNB1 protein, human; C495267:CTNNB1 protein, mouse; D003598:Cytoskeletal Proteins; C116887:EPB41L3 protein, human; C488402:Epb41l3 protein, mouse; D008565:Membrane Proteins; D008840:Microfilament Proteins; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D051176:beta Catenin