TY - JOUR
T1 - Earlier Helicobacter pylori infection increases the risk for the N-methyl-N-nitrosourea-induced stomach carcinogenesis in Mongolian gerbils
AU - Cao, Xueyuan
AU - Tsukamoto, Tetsuya
AU - Nozaki, Koji
AU - Tanaka, Harunari
AU - Shimizu, Nobuyuki
AU - Kaminishi, Michio
AU - Kumagai, Toshiko
AU - Tatematsu, Masae
PY - 2002/12/1
Y1 - 2002/12/1
N2 - Helicobacter pylori (H. pylori) is now well known to be associated with stomach cancer, with infection during childhood rather than as an adult considered to be more important for carcinogenesis. To evaluate the difference in susceptibility to stomach carcinogenesis in relation to age of acquisition of H. pylori infection, we designed an experiment involving inoculation of H. pylori ATCC43504 followed by N-methyl-N-nitrosourea (MNU) treatment at different ages. Four-week-old male Mongolian gerbils (MGs) were divided into twelve groups. H. pylori was inoculated at 4, 18 and 32 weeks of age, as representatives of early, middle and late infection, respectively. Two weeks later, the animals were treated with MNU. Groups without H. pylori and/or MNU were included as controls. The incidences of adenocarcinomas at 52 weeks after the inoculation in the early (H. pylori+MNU), middle (H. pylori+MNU), and late (H. pylori+MNU) group were 60% (12/20), 18.4% (2/11), and 10% (2/20), respectively. The corresponding figures were 14.8% (4/27), 0% (0/11), and 0% (0/21) in the MNU-alone groups. A higher titer of serum IgG for H. pylori and higher gastrin level were seen in the early-infected compared to the middle and the late groups (P<0.01). The results clearly demonstrated that early acquisition of H. pylori significantly increases gastric chemical carcinogenesis with MNU, as compared to the case with later infection, possibly because of differences in host gastric mucosal factors and immunologic responses.
AB - Helicobacter pylori (H. pylori) is now well known to be associated with stomach cancer, with infection during childhood rather than as an adult considered to be more important for carcinogenesis. To evaluate the difference in susceptibility to stomach carcinogenesis in relation to age of acquisition of H. pylori infection, we designed an experiment involving inoculation of H. pylori ATCC43504 followed by N-methyl-N-nitrosourea (MNU) treatment at different ages. Four-week-old male Mongolian gerbils (MGs) were divided into twelve groups. H. pylori was inoculated at 4, 18 and 32 weeks of age, as representatives of early, middle and late infection, respectively. Two weeks later, the animals were treated with MNU. Groups without H. pylori and/or MNU were included as controls. The incidences of adenocarcinomas at 52 weeks after the inoculation in the early (H. pylori+MNU), middle (H. pylori+MNU), and late (H. pylori+MNU) group were 60% (12/20), 18.4% (2/11), and 10% (2/20), respectively. The corresponding figures were 14.8% (4/27), 0% (0/11), and 0% (0/21) in the MNU-alone groups. A higher titer of serum IgG for H. pylori and higher gastrin level were seen in the early-infected compared to the middle and the late groups (P<0.01). The results clearly demonstrated that early acquisition of H. pylori significantly increases gastric chemical carcinogenesis with MNU, as compared to the case with later infection, possibly because of differences in host gastric mucosal factors and immunologic responses.
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U2 - 10.1111/j.1349-7006.2002.tb01237.x
DO - 10.1111/j.1349-7006.2002.tb01237.x
M3 - Review article
C2 - 12495468
AN - SCOPUS:0036949491
SN - 0910-5050
VL - 93
SP - 1293
EP - 1298
JO - Japanese Journal of Cancer Research
JF - Japanese Journal of Cancer Research
IS - 12
ER -