Abstract：
Primordial odontogenic tumor (POT) is composed of variably cellular myxoid connective tissue, surrounded by cuboidal to columnar odontogenic epithelium resembling the inner epithelium of the enamel organ, which often invaginates into the underlying connective tissue. The tumor is delimited at least partially by a thin fibrous capsule. It derives from the early stages of tooth development. Syndecan-1 is a heparan sulfate proteoglycan that has a physiological role in several cellular functions, including maintenance of the epithelial architecture, cell-to-cell adhesion and interaction of cells with extracellular matrix, and with diverse growth factors, stimulating cell proliferation. Ki-67 is considered the gold standard as a cell proliferation marker. The aim of this study was to examine the expression of Syndecan-1 and Ki-67 proliferation index in POT and normal tooth germs to better understand the biological behavior of this tumor. Results showed that Syndecan-1 was more intensely expressed in subepithelial mesenchymal areas of POT, in a pattern that resembles the early stages of tooth development. The cell proliferation index (4.1%) suggests that POT is a slow growing tumor. Syndecan-1 expression in tooth germs in late cap and early bell stages was similar to POT, showing immunopositivity in subepithelial mesenchymal condensed areas. The immunohistochemical findings showed a pattern in which the population of subepithelial mesenchymal cells exhibited greater proliferative activity than the central portion of the dental papilla.
摘要：
原始牙源性肿瘤(POT)由不同细胞的黏液样结缔组织组成，被类似于釉质器官内上皮的立方形至柱状牙源性上皮包围，经常内陷到下面的结缔组织中。肿瘤至少部分地由薄的纤维囊界定。它源于牙齿发育的早期阶段。Syndecan-1是一种硫酸乙酰肝素蛋白聚糖，在几种细胞功能中具有生理作用，包括维持上皮结构，细胞间粘附和细胞与细胞外基质的相互作用，并且具有不同的生长因子，刺激细胞增殖。Ki-67被认为是作为细胞增殖标志物的金标准。这项研究的目的是检查Syndecan-1和Ki-67增殖指数在POT和正常牙胚中的表达，以更好地了解该肿瘤的生物学行为。结果显示Syndecan-1在POT的上皮下间充质区域表达更强烈，类似于牙齿发育的早期阶段。细胞增殖指数(4.1%)表明POT是一种生长缓慢的肿瘤。Syndecan-1在晚期和早期钟形阶段的牙胚中的表达与POT相似，在上皮下间充质凝聚区显示免疫阳性。免疫组织化学结果显示，上皮下间充质细胞群表现出比牙乳头中央部分更大的增殖活性。
