Experiments On Regulation Mechanism Of Bone Morphogenetic Protein Gene In Oral Tumors' Pathology

1 Gene mutation of BMP2 in ameloblastomaAs one of the many growth factors, Bone Morphogenetic proteins (BMPs) play very important roles in the pathological mechanism of many kinds of tumors. Ameloblastomas are the most common tumors among odontogenic tumors. Many previous studies showed that ameloblastomas came from enamel organ of embryonic developmental stage, but the tumorous epithelium cell lost the ability of forming hard tissue. Studies showed that enamel orange expressed abundant BMP; which could induce the differentiation of the odontoblasts and played important roles in the formation of dentin and enamel. To study the pathological mechanism of ameloblastomas, we examined the expression of BMP and analyzed the function in the development of ameloblastoma. The result showed that BMP and BMP2 , 4 mRNA of 24 specimens of ameloblastomas were detected with immunohistochemical and in situ hybridization technique, just like they existed in the enamel organs . But bioassay of bone inducing activity showed that the tissues of ameloblastomas that contained abundant BMP lost the ability to induce bone formation. To make the reasons that resulted in the losing of bone inducing activity of BMP clear, cDNA fragment of coding mature domain of BMP2 was cloned from RNA with RT-PCR method. The fragment was sequenced and analyzed. The result of sequence analysis showed that 1 of 3 samples was found BMP2 gene mutation. Two point mutation of BMP2 gene encoding mature peptide were detected:...