Expression of HOXC13 in ameloblastoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the expression of HOXC13 mRNA in ameloblastoma (AB), and to investigate its biological significance.</p><p><b>METHODS</b>HOXC13 mRNA was examined in 47 cases of AB (primary AB 29 cases, recurrent AB 14 cases, malignant AB 4 cases). 2 cases of fibrous dysplasia of bone, 10 cases of keratocystic odontogenic tumor (KCOT) and 7 cases of normal oral mucosa were selected as control.</p><p><b>RESULTS</b>The positive rates of HOXC13 mRNA in AB, KCOT, and normal oral mucosa were 97.9% (46/47), 7/10 and 3/7, respectively. There was a significant difference among AB, OKC and normal mucosa (chi(2) = 21.665, P = 0.001). For HOXC13, the keratinizing cells and granulizing cells in AB were negative, some fibroblasts were positive, 2 cases of fibrous dysplasia of bone were positive.</p><p><b>CONCLUSIONS</b>HOXC13 was highly expressed in AB. The expression of HOXC13 mRNA in AB had heterogeneity, which could improve the epithelial proliferation, and its loss may lead to the cornification and degeneration of epithelial cells.</p>

DNA methylation of human telomerase reverse transcriptase promoter region in human ameloblastoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the DNA methylation of human telomerase reverse transcriptase (hTERT) promoter in ameloblastoma (AB) and investigate its clinical biological significance.</p><p><b>METHODS</b>DNA methylation of hTERT promoter in 12 cases of AB and 11 cases of normal oral mucosa were detected by methylation-specific PCR.</p><p><b>RESULTS</b>The positive cases of unmethylated hTERT promoter region in AB and normal oral mucosa were 4 (4/12) and 6 (6/11), respectively (P < 0.001). The positive cases of methylated hTERT promoter region in AB and normal oral mucosa were 11 (11/12) and 3 (3/11), respectively. Four cases of AB and 1 case of normal oral mucosa showed both DNA methylation and unmethylation of hTERT promoter region in the same time.</p><p><b>CONCLUSIONS</b>DNA methylation of of hTERT promoter region in AB was more common than that in normal oral mucosa. The DNA methylation in hTERT promoter maybe regulate hTERT gene expression.</p>

Expression of p21WAF1, p27KIP1 and cyclin E in ameloblastoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of cyclin E mRNA, p21(WAF1) mRNA and p27(KIP1) protein in human ameloblastoma (AB), and to explore the clinical and biological characteristics of AB.</p><p><b>METHODS</b>The expression of cyclin E mRNA, p21(WAF1) mRNA and p27(KIP1) protein in 54 cases of human AB were detected by in situ hybridization or immunohistochemistry (SP method).</p><p><b>RESULTS</b>The positive expression rate of cyclin E mRNA in the cytoplasm or cell nucleus of AB was 66.7% (36/54). The expression of cyclin E mRNA increased with AB recurrence and malignant transformation, and the difference of expression among primary AB, recurrent AB, and malignant AB, was statistically significant. The positive expression ratio of cyclin E mRNA in OKC was 50.0% (8/16). The p21(WAF1) mRNA expression in the cytoplasm or cell nucleus of AB decreased, and the positive ratio was 22.6% (12/54) in AB, 37.5% (6/16) in OKC, respectively. The p27(KIP1) protein expression in the cell nucleus of AB was positive in a small number of cases, and the positive rate was 16.7% (9/54) in AB, 6.3% (1/16) in OKC, respectively.</p><p><b>CONCLUSIONS</b>The genesis and invasion of AB is associated with the cell proliferation and differentiation, and regulated by the higher expression of cyclin E and the lower expression of p21(WAF1) and p27(KIP1).</p>

Expression of telomerase activity and c-myc and stimulatory protein 1 in human ameloblastoma / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the oncogene transcriptor c-myc, stimulatory protein 1 (SP1) expression in ameloblastoma (AB) and their relation with telomerase reverse transcripase (hTERT), and to investigate the clinical biological characteristics of AB.</p><p><b>METHODS</b>The expression was observed in AB by in situ hybridization and SP method.</p><p><b>RESULTS</b>The positive rates of c-myc mRNA, hTERT mRNA and SP1 protein were 81.5% (44/54), 94.4% (51/54) and 83.3% (45/54), respectively. Their positive rates increased as AB recurred and transformed malignantly. A strong correlation was found between hTERT and c-myc, hTERT and SP1 (rs = 0.853, P < 0.001; rs = 0.900, P < 0.001).</p><p><b>CONCLUSION</b>Activity of telomerase plays an important role in the tumorigenesis development of AB. Increasing of hTERT expression may be related to c-myc and SP1. The expression of these three parameters has a significant correlation with the clinical biological characteristics of AB.</p>