title: Autophagy in the intestinal epithelium is not involved in the pathogenesis of intestinal tumors.
abstract: Autophagy has been demonstrated to be associated with the pathogenesis of cancer, but no consensus has been reached about its precise role. Therefore, we investigated whether autophagy in the intestinal epithelium is involved in the pathogenesis of intestinal tumors. To evaluate the relationship between autophagy and intestinal tumors, GFP-LC3-APC(min/+) mice were generated by mating GFP-LC3 transgenic mice with APC(min/+) mice. Autophagy was weakly induced in the intestinal polyp regions of the mice in comparison to their non-polyp regions. Under starved conditions, autophagy was not induced in the polyp regions, whereas it was observed in the non-polyp regions. Then, to examine whether a lack of autophagy in the intestinal epithelium enhances the induction of intestinal tumor, Atg7flox/flox:vil-cre-APC(min/+) mice, in which Atg7 had been conditionally deleted in the intestinal epithelium, were generated by mating Atg7flox/flox:vil-cre mice with APC(min/+) mice. However, there was no significant difference in the number of intestinal polyps between the Atg7flox/flox:vil-cre-APC(min/+) and the corresponding control Atg7flox/flox-APC(min/+) mice. These results indicate that autophagy in the intestinal epithelium is not involved in the pathogenesis of intestinal tumors, and future research should focus on regulating autophagy as a form of cancer therapy.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Nishiumi
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Fujishima
authors.forename: Jun
authors.initials: J
authors.lastname: Inoue
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Masuda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Azuma
authors.forename: Masaru
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D001343:Autophagy; D005260:Female; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology*; D007414:Intestinal Neoplasms / Q000378:metabolism / Q000473:pathology*; D007417:Intestinal Polyps / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000378:metabolism
chemical_list: C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D049452:Green Fluorescent Proteins