Induction of glutathione S-transferase π as a bioassay for the evaluation of potency of inhibitors of benzo(a)pyrene-induced cancer in a murine model
✍ Scribed by Xun Hu; Patrick J. Benson; Sanjay K. Srivastava; Hong Xia; Richard J. Bleicher; Howard A. Zaren; Sanjay Awasthi; Yogesh C. Awasthi; Shivendra V. Singh
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- French
- Weight
- 135 KB
- Volume
- 73
- Category
- Article
- ISSN
- 0020-7136
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✦ Synopsis
There is a growing need for short-term and cost-effective bioassay to assess the efficacy of potential chemo-preventive agents. We report that the induction of glutathione (GSH) S-transferase (mGSTP1-1) by a chemo-preventive agent can be used as a reliable marker to assess its efficacy in retarding chemical carcinogenesis induced by benzo(a)pyrene (BP), which is a widespread environmental pollutant and believed to be a risk factor in human chemical carcinogenesis. This conclusion is based on 1) the relative contribution of mGSTP1-1 of the liver and forestomach of female A/J mice in the detoxification of the ultimate carcinogenic metabolite of BP, (؉)-anti-7,8-dihydroxy-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene [(؉)-anti-BPDE]; and 2) a positive correlation between the induction of hepatic and forestomach mG-STP1-1 by 5 naturally occurring organosulfides (OSCs) from garlic (diallyl sulfide, diallyl disulfide, diallyl trisulfide, dipropyl sulfide and dipropyl disulfide) and their effectiveness in preventing BP-induced forestomach neoplasia in mice. In the liver, the combined contribution of other GSTs in the detoxification of (؉)-anti-BPDE was far less than the contribution of mGSTP1-1 alone. Likewise, in the forestomach, the contribution of mGSTP1-1 far exceeded the combined contribution of other GSTs. Studies on the effects of OSCs against BPinduced forestomach neoplasia revealed a good correlation between their chemo-preventive efficacy and their ability to induce mGSTP1-1 expression in the liver (r ؍ ؊0.89; p F 0.05) as well as in the forestomach (r ؍ ؊0.97; p F 0.05). Our results suggest that the induction of mGSTP1-1 may be a reliable marker for evaluating the efficacy of potential inhibitors of BP-induced cancer in a murine model.