Study on the Mechanism Regulating Cell Differentiation in Salivary Gland Tumor

我们研究了整合素在涎腺肿瘤中的表达。Α-2、α-3和β-1在正常涎腺、多形性腺瘤、粘液表皮样癌和腺样囊性癌中的表达相似。α-6和β-4在正常对照组、PA组和MC组均在基底面表达，而在Acc组则呈散在分布。因此，我们推测α-6-β-4可能与腺样囊性癌的侵袭性有关，而不是与细胞分化有关。其次，我们研究了转化生长因子βS及其受体的表达，以刺激整合素的表达和细胞外基质的产生。转化生长因子β-3和转化生长因子β-RII在MC中表达相似，而转化生长因子β-1和转化生长因子β-2在MC中不表达。前者在几乎所有唾液上皮细胞，尤其是表皮样细胞中均有不同程度的表达。而在粘液细胞和透明细胞中未检测到。用自制抗体对αv整合素配体骨桥蛋白的定位进行了免疫组织化学观察。OPN在所有NSG和涎腺良恶性肿瘤中均有表达。OPN表达与涎腺细胞分化有关，细胞周期调控因子p53、p21和Cycline E的表达因细胞成分不同而不同。然而，它的多样性被认为是由于它们的增殖能力。端粒酶活性与涎腺肿瘤的恶性程度有关，但与细胞分化无关。

We investigated integrin expression in salivary gland tumors. Α2, α3 and β1 similarly expressed in normal salivary gland (NSG) and pleomorphic adenoma (PA), mucoepidermoid carcinoma (MC), and adenoid cystic carcinoma (ACC). On the other hand, α6 and β4 expressed at basal surface in NSG, PA and MC, but in scattered pattern in ACC. Therefore, we speculated that α6 β4 might have association with invasiveness of ACC rather than cell differentiation.Secondly, we investigated expression of TGF βs and their receptors which stimulate integrin expression and production of extra-cellular matrix. TGF β3 and TGF β RII expressed similarly, but TGF β1 and TGF β2 did not in MC. The former was observed with different intensity in almost all the salivary epithelial cells, in particular epidermoid cells. On the other hand, they were not detected in mucous cells and clear cells. Similar expression pattern was observed in PA and ACC.We immunohistochemically observed localization of osteopontin (OPN) which is ligand for αv integrin using the self-made antibody. OPN expression was observed in all the NSGs and benign and malignant salivary gland tumors tested. OPN was observed in ductal epithelial cells, but not in mucous cells of all the aboved tissues, which suggests the relationship between OPN expression and cell differentiation of salivary gland.Cell cycle regulators, p53, p21 and cycline E, were differently expressed depending on cell component. However, its diversity was supposed to be due to their proliferative ability. The relationship was observed between telomerase activity and malignancy of salivary gland tumor, but not cell differentiation.