Immunohistochemical Features of 3,3′,4,4′-Tetrachloroazobenzene-Induced Rat Gingival Lesions

Abstract

Gingival lesions of squamous hyperplasia, cystic keratinizing hyperplasia (CKH), and squamous cell carcinoma (SCC) can be induced in rats treated by chronic gavage with 10-100 mg/kg 3,3 0 ,4,4 0 -tetrachloroazobenzene. We evaluated gingival squamous hyperplasia (GSH), CKH, and SCC for the immunohistochemical pattern of expression of carcinogenesis-associated markers. The 3 types of lesions and controls were stained with proliferation markers (proliferating cell nuclear antigen [PCNA] and cyclin-D1), tumor-suppressor markers (b-catenin and mammary serine protease inhibitor [maspin]) and stroma-related markers (a-smooth muscle actin [SMA] and osteonectin/SPARC). The lesions had common immunohistochemical characteristics that differed in their expression patterns among the various diagnoses. PCNA and cyclin-D1 expression was higher in GSH, CKH, and SCC than in controls. The normal membranous expression of b-catenin was lower in GSH, and almost absent in CKH and SCC. Maspin expression was similar in GSH and controls, whereas both CKH and SCC showed decreased expression. SMA and/or osteonectin/SPARC were seen in stromal cells in CKH and SCC. Collectively, there appears to be a progression from hyperplastic and cystic lesions toward malignancy based on the morphological changes, supported by the expression of carcinogenesis-associated proteins. The exact sequence of events leading to SCC remains to be defined in a time-dependent manner.

Impact of Maspin Polymorphism rs2289520 G/C and Its Interaction with Gene to Gene, Alcohol Consumption Increase Susceptibility to Oral Cancer Occurrence

“…Maspin (mammary serine protease inhibitor), a 42-KDa cytoplasmic protein and commonly known as SERPINB5, has been reported as a tumor suppressor by inhibiting cell proliferation, cell cycle progression, cell motility, invasion, and metastasis [ 4 – 9 ]. Gene expression of Maspin are decreased in gingival cystic keratinizing hyperplasia (CKH) and gingival squamous cell carcinoma (SCC) among rats treated with 10–100 mg/kg 3,3’,4,4’-tetrachloroazobenzene, a carcinogen of dioxin-like compound, compared to controls, and the loss of Maspin expression is correlated with extensive and penetrating lesions [ 8 ]. Lower expression of Maspin was also found in cell lines derived from highly invasive human oral squamous cell carcinoma (OSCC) [ 4 , 7 ].…”