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Background Non-coding RNA molecules, such as microRNAs, may play an important role in carcinogenesis. Recent studies have indicated that microRNAs are involved in initiation and progression of various malignancies. However, little work has been done to compare the microRNA expression patterns in oral cancer. In this study, we constructed an animal model of oral squamous cell carcinoma to investigate expression profiles of microRNAs in oral carcinogenesis. Methods The animal model of oral squamous cell carcinoma was conducted by tri-weekly (Monday, Wednesday, and Friday) painting with 5% DMBA in acetone. Six Syrian hamsters, including three from the treated group and three from the control group, were used as a training group for microRNA microarray analysis. All microarray data were analyzed by Significance Analysis of Microarrays (SAM) and CLUSTER 3.0 software, and this result was further confirmed by qRT-PCR assay. Results Seventeen microRNAs were differentially expressed in oral squamous cell carcinoma. Five microRNAs (hsa-miR-21, hsa-miR-200b, hsa-miR-221, hsa-miR-338, and mmu-miR-762) were significantly upregulated and twelve microRNAs (hsa-miR-16, hsa-miR-26a, hsa-miR-29a, hsa-miR-124a, hsa-miR-125b, mmu-miR-126-5p, hsa-miR-143, hsa-miR-145, hsa-miR-148b, hsa-miR-155, hsa-miR-199a, and hsa-miR-203) were down-regulated in cancer tissues. The expression levels of hsa-miR-21 and hsa-miR-16 seen with Stem-loop qRT-PCR were also seen in microarray analysis in all samples. Conclusion Our findings identified specific microRNA expression in oral squamous cell carcinoma and suggested that microRNAs have a role in oral carcinogenesis.

To study the relationship between the expression of thrombospondin-1 (TSP-1) and the angiogenesis in mucoepidermoid carcinoma.Immunohistochemistry were applied to detect the expression of TSP-1 and the value of microvessel density (MVD) in 45 mucoepidermoid carcinoma patients.Positive expressions of TSP-1 protein were detected in 26 of the 45 (57. 78%) cases. Most positive staining for TSP-1 was observed in the cytoplasm of the cancer cells, some of those were in the extracellular matrix. The mean MVD in 45 cases with mucoepidermoid carcinoma was 60. 68 +/- 19.84 vessels per 100 field of vision. Tumors with a high expression of TSP-1 showed a low value of MVD and the correlation between TSP-1 immunocompetence and microvessel density was highly significant (r(s) = -0.942, P0.001).The TSP-1 is expressed in most mucoepidermoid carcinoma and were associated with neovascularization. TSP-1 is likely to inhibit the extensive neovascularization and increased TSP-1 expression might inhibit angiogenic phenotype in mucoepidermoid carcinoma.

To study the expression of inhibitor-1 of DNA binding/differentiation-1 (Id-1) and thrombospondin-1 (TSP-1) genes in mucoepidermoid carcinoma of different malignant degree and analyze the relationship between them.Using immunohistochemistry (IHC) staining technique, TSP-1 and Id-1 proteins in the mucoepidermoid carcinoma of different malignant degree, including well-differentiated, moderately differentiated and poorly differentiated mucoepidermoid carcinoma, and normal salivary gland tissues were detected.The positive rate of Id-1 and TSP-1 in normal salivary glands were apparently lower than that in malignant mucoepidermoid carcinoma(P = 0.000, P = 0.013). The positive rate of Id-1 in moderately and poorly differentiated mucoepidermoid carcinoma was higher than that of the well-differentiated (P = 0.001, P = 0.002). However, the positive expression of Id-1 showed no relationship between the moderately and poorly differentiated mucoepidermoid carcinoma(P0.05). The positive rate of TSP-1 in poorly differentiated mucoepidermoid carcinoma was less than that of the well-differentiated(P = 0.014). The positive expression of TSP-1 showed no relationship between the moderately and poorly differentiated mucoepidermoid carcinoma(P0.05), and the positive expression of it also showed no relationship between the moderately and well differentiated mucoepidermoid carcinoma (P0.05). The expression of Id-1 and TSP-1 showed negative correlation(r = -0.394, P = 0.002).The expression of TSP-1 may inhibit the development of the mucoepidermoid carcinoma, contrarily, the expression of Id-1 may prompt the development of the mucoepidermoid carcinoma. The expression of Id-1 and TSP-1 has negative correlation.