Abstract :
To clarify pathological and molecular mechanisms of gastric cancer, various experimental models have
been purposed. H. pylori is one of the most important factors that classified as a class I carcinogen. N-nitroso
compounds and salt have been proposed by several studies to be probable promoters of gastric carcinogenesis. The
aim of our studies was to develop simplified gastric cancer models in rats using H. pylori, MNU and sodium
chloride.
A total of 48 rats were divided into 4 experimental groups including: group 1: H. pylori inoculation + 30
ppm MNU in drinking water for 20 weeks, group 2: 30 ppm MNU in drinking water for 20 weeks, group 3: MNU
100 mg/kg by gavage feeding on day 1st and day 14th, and group 4: saturated NaCl solution fed twice a week for the
3 weeks + MNU 100 mg/kg by gavage feeding on day 1st and day 14th.
Results: In group 1, two rats developed gastric adenocarcinomas at week 52nd (50% incidence, n = 4),
while in the group 2, no gastric adenocarcinoma was found. In group 3, could induce the development of squamous
cell carcinoma (SCC) in forestomachs of 5 rats at week 9th, 13th, 16th, and 20th. Overall cancer incidence in group
3 was 50% (n = 10). Eight rats in group 4 developed forestomach SCC at week 6th, 9th, 13th, 16th, and 20th. Overall
cancer incidence in group 4 was 47% (n = 17).
Conclusion: In this study, we could induce gastric adenocarcinoma by H. pylori infection and MNU
administration in drinking water. In addition, short-term intragastric administration of MNU with or without saturated
NaCl led to the development of forestomach SCC in rats. These rat models may be suitable in further studies
to demonstrate molecular mechanisms and to evaluate efficacy of new modality of treatment options in stomach
cancer. |
file/Thai-Journal-of-gastroenterology-vol-11-no-1-4884406.pdf