Promotional effects of CO2 laser on DMBA-induced hamster buccal pouch carcinogenesis as shown by immunohistochemistry of the placental form of glutathione S-transferase
✍ Scribed by Iida, Keisuke; Kato, Mugio; Yoshida, Kenji; Kurita, Kenichi; Tatematsu, Masae
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 281 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0196-8092
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✦ Synopsis
Background and Objective:
The purpose of the present study was to investigate the kinetics of the expression of the placental form of glutathione S-transferase (GST-P), a useful marker of premalignant lesions, and cell proliferation after CO 2 laser surgery on the carcinogen-initiated epithelium. Study Design/Materials and Methods: CO 2 laser incisions were made on buccal pouch epithelium of 36 hamsters after initiation by 9,10-dimethyl-1,2-benzanthracene (DMBA) (group 1, G1), and scalpel incisions were similarly made on 33 animals (group 2, G2). Twenty animals not treated further after initiation were used as DMBA-treated controls. Incidence of malignant transformation, expression of GST-P, and cell proliferation were examined.
Results:
The incidence of malignant transformation in G1 and G2 increased significantly (G1: P < 0.001; G2: P < 0.05) compared with that in DMBA-treated controls. GST-P expression of hyperplasia in G1 and G2 decreased significantly (P < 0.001) compared with that in DMBA-treated controls. In hyperplasia, cell proliferation of the GST-P-negative area was significantly (P < 0.001) higher than that of the GST-P-positive area.
Conclusion:
The incisions, particularly by the CO 2 laser, on the initiated areas made expression of GST-P decrease and cell proliferation increase in the GST-P-negative areas. These incisions may serve to promote malignant transformation. Lasers Surg. Med. 24:360-367, 1999.