title: Evaluation of apoptosis induction using PARP cleavage on gastric adenocarcinoma and fibroblast cell lines by different strains of Helicobacter pylori.
abstract: Helicobacter pylori is one of the most common pathogens affecting humans and is the major environmental factor in the development of gastric cancer increasing from 4 to 6 folds the risk of its development. Variations in cancer risk among H. pylori infected individuals may correlate to difference in H. pylori strains, variable host characteristics and specific interactions between host and microbial determinants. To determine the effect of different strains of H. pylori on cellular apoptosis this study was designed an in vitro model using AGS and HEF cell lines. After specified time intervals total cell proteins was extracted and subjected to SDS-PAGE and immunoblotting using anti poly ADP-ribose polymerase (PARP) antibody. Decrease in densitometric value of PARP was indicative of higher level of apoptosis. The ability of apoptosis induction in AGS and HEF cell lines by wild type (cagA+/vacA+), cagA-/vacA+, vacA-/cagA+ and double negative (cagA-/vacA-) strains were significantly different. The assessed apoptosis in AGS cell line co-cultured with wild type strain was 3.22 +/- 0.2 in 24 h, 2.8 +/- 0.1 in 48 and 2.1 +/- 0.09 in 72 h of incubation time. Similar assessment with cagA-/vacA+ strains in AGS cells was 4.17 +/- 1.49 in 24 h, 3.32 +/- 0.45 in 48 h and 2.32 +/- 0.61 in 72 h incubation. A variation in apoptotic potential between the H. pylori strains on two cells (AGS and HEF) was observed. Based on present results, it is concluded that H. pylori strains as well as target cell types are important in pathogenesis and induction of apoptosis during a specified time interval.
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, Guilan University Complex, Rasht-Tehran Road, Rasht 3477, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Mojtahedi
authors.forename: Rasoul
authors.initials: R
authors.lastname: Salehi
authors.forename: Farahtaj
authors.initials: F
authors.lastname: Navabakbar
authors.forename: Hasan
authors.initials: H
authors.lastname: Tamizifar
authors.forename: Hamid
authors.initials: H
authors.lastname: Tavakkoli
authors.forename: Vincent
authors.initials: V
authors.lastname: Duronio
mesh_terms: D000230:Adenocarcinoma / Q000382:microbiology* / Q000473:pathology; D000942:Antigens, Bacterial / Q000378:metabolism; D017209:Apoptosis; D001426:Bacterial Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D003720:Densitometry; D005347:Fibroblasts / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D012306:Risk; D013045:Species Specificity; D013274:Stomach Neoplasms / Q000382:microbiology* / Q000473:pathology
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; D011065:Poly(ADP-ribose) Polymerases