title: Increased induction of apoptosis by Propionibacterium freudenreichii TL133 in colonic mucosal crypts of human microbiota-associated rats treated with 1,2-dimethylhydrazine.
abstract: Propionibacterium freudenreichii, a food-grade bacterium able to kill colon cancer cell lines in vitro by apoptosis, may exert an anticarcinogenic effect in vivo. To assess this hypothesis, we administered daily 2 x 10(10) colony-forming units (CFU) of P. freudenreichii TL133 to human microbiota-associated (HMA) rats for 18 d. Either saline or 1,2-dimethylhydrazine (DMH) was also administered on days 13 and 17 and rats were killed on day 19. The levels of apoptosis and proliferation in the mid and distal colon were assessed by terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) and proliferating cell nuclear antigen (PCNA) immunolabelling, respectively. The administration of P. freudenreichii TL133 significantly increased the number of apoptotic cells in DMH-treated rats compared to those given DMH only (P < 0.01). Furthermore, propionibacteria were able to decrease the proliferation index in the distal colon after treatment with DMH (P < 0.01). Conversely, propionibacteria alone did not exert such an effect on healthy colonic mucosa. P. freudenreichii TL133 thus facilitated the elimination of damaged cells by apoptosis in the rat colon after genotoxic insult and may play a protective role against colon cancer.
authors.affiliation: INRA, Agrocampus Rennes, UMR1253 Science et Technologie du Lait et de l'Oeuf, Rennes F-35000, France.
authors.forename: Annaïg
authors.initials: A
authors.lastname: Lan
authors.forename: Aurélia
authors.initials: A
authors.lastname: Bruneau
authors.forename: Martine
authors.initials: M
authors.lastname: Bensaada
authors.forename: Catherine
authors.initials: C
authors.lastname: Philippe
authors.forename: Pascale
authors.initials: P
authors.lastname: Bellaud
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rabot
authors.forename: Gwénaël
authors.initials: G
authors.lastname: Jan
mesh_terms: D019813:1,2-Dimethylhydrazine / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002273:Carcinogens / Q000494:pharmacology*; D002432:Cecum / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D003106:Colon / Q000187:drug effects / Q000382:microbiology* / Q000473:pathology; D005285:Fermentation; D005856:Germ-Free Life; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects / Q000382:microbiology / Q000473:pathology; D008297:Male; D011424:Propionibacterium / Q000302:isolation & purification / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002273:Carcinogens; D019813:1,2-Dimethylhydrazine