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Sequential expression of inducible nitric oxide synthase and cyclooxygenase-2 during DMBA-induced hamster buccal
Soo-A Kim1, Sang-Gun Ahn, Do Kyung Kim
1Oral Biology Research Institute, BK 21 Project, Chosun University School of Dentistry, Gwangju, Korea.
Background:
Although it is known that iNOS and COX-2 are abundantly expressed in oral premalignant and malignant lesions, respectively, the interaction between iNOS and COX-2 has not been extensively studied. The purpose of this study was to examine the alteration of the iNOS and COX-2 expression level during hamster buccal pouch (HBP) carcinogenesis.
Materials And Methods:
The expression of both iNOS and COX-2 on normal, dysplastic mucosa and squamous cell carcinoma (SCC) from different differentiation stages in 7, 12-dimethylbenz[a]anthracene (DMBA)-induced HBP carcinogenesis was examined using immunohistochemical analysis.
Results:
The mean values of both iNOS and COX-2 expression increased gradually from control to dysplastic lesions and more to invasive SCC. The highest mean expression was SCC. The differences between both iNOS and COX-2 expression in the normal and that in the dysplastic and carcinoma lesions were statistically significant.
Conclusion:
The results suggest that iNOS can enhance its ability to promote tumor growth in cooperation with COX-2. The expression of iNOS and COX-2 may be one of the factors that contribute to oral carcinogenesis.
Insights
Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression increases during oral carcinogenesis. Their combined action may promote tumor growth, highlighting their role in oral cancer development.
Area of Science:
- Oncology
- Molecular Biology
- Oral Pathology
Background:
- Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are known to be expressed in oral premalignant and malignant lesions.
- The interaction and co-expression patterns of iNOS and COX-2 during oral carcinogenesis remain incompletely understood.
Purpose of the Study:
- To investigate the expression levels of iNOS and COX-2 throughout the process of hamster buccal pouch (HBP) carcinogenesis.
- To elucidate the potential cooperative role of iNOS and COX-2 in oral tumor progression.
Main Methods:
- Immunohistochemical analysis was employed to assess iNOS and COX-2 expression.
- The study examined normal mucosa, dysplastic lesions, and squamous cell carcinoma (SCC) at various differentiation stages.
- Hamster buccal pouch carcinogenesis was induced using 7,12-dimethylbenz[a]anthracene (DMBA).
Main Results:
- Both iNOS and COX-2 expression showed a gradual increase from normal tissue to dysplastic lesions and further to invasive SCC.
- Squamous cell carcinoma (SCC) exhibited the highest mean expression levels for both iNOS and COX-2.
- Statistically significant differences in iNOS and COX-2 expression were observed between normal tissues and dysplastic/carcinomatous lesions.
Conclusions:
- The findings suggest that iNOS may enhance tumor growth by cooperating with COX-2.
- Elevated expression of iNOS and COX-2 is implicated as a contributing factor in oral carcinogenesis.
- Targeting the iNOS-COX-2 pathway could offer potential therapeutic strategies for oral cancer.
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