细胞角蛋白18及其基因在牙源性角化囊肿衬里上皮中表达的意义

目的检测细胞角蛋白18（CK18）及其基因在牙源性角化囊肿（OKC）衬里上皮中的表达。方法选取32例OKC的衬里上皮组织，分别进行CK18、CK8和CK19单克隆抗体的免疫组织化学染色。对其中12例使用RT- PCR法检测CK18 mRNA，观察其在衬里上皮中的表达；同时使用CK18基因探针进行原位杂交，检测CK18 mRNA在衬里上皮细胞层的定位表达。结果在免疫组织化学染色中, 17例CK18蛋白在OKC衬里上皮的表层细胞层表达为弱阳性；27例CK18蛋白在棘细胞层上层染色为阳性；14例CK18蛋白在棘细胞层染色为阳性；所有标本基底细胞层染色呈阴性。RT- PCR法检测见4例CK18 mRNA表达为强阳性，8例表达为弱阳性。原位杂交法检测见8例CK18 mRNA在棘细胞层和棘细胞层上层呈阳性，4例在上皮基底细胞层和角化层呈阳性。CK8蛋白在所有32例OKC衬里上皮基底细胞层均有表达。CK19蛋白在23例OKC衬里上皮表层均有表达。结论CK18在OKC衬里上皮的表达由基底细胞层向棘细胞层迁移，CK18蛋白免疫组织化学染色阳性表达与CK18 mRNA原位杂交法阳性表达不同，提示CK18可能与衬里上皮的增殖活性有关，OKC衬里上皮中可能存在CK18蛋白和CK18 mRNA表达的调控因子。

Cytokeratin 18 and Their Gene Expression in Jaw Odontogenic Keratocyst Epithelial Lining

OBJECTIVE: To examine cytokeratin 18(CK18) and it's gene in jaw odontogenic keratocyst (OKC) epithelial lining. METHODS: The epithelial linings of 32 cases were subject to monoclonal antibody immunohistochemical staining for CK18, CK8 and CK19. RT-PCR and in situ hybridization for CK18 mRNA were conducted in 12 of 32 cases in keratocyst epithelial cell linings. RESULTS: In 17 cases, CK18 were observed in keratinized surface layers, though weakly positive. In 27 cases, CK18 were positive in the granular cell layers. CK18 were also positive in the spinous cell layers in 14 cases. In all cases, CK18 was negative in basal cell layers. By RT-PCR, 4 cases expressed CK18 strongly, 8 cases weakly. By in situ hybridization, 8 cases expressed CK18 mRNA positively in both spinous and granular cell layers, and 4 cases positively in basal and keratinized cell layers. CK8 were expressed in basal cell layers of keratocyst epithelial linings. In 23 cases, CK19 were expressed in surface cell layers of keratocyst epithelial linings. CONCLUSION: The expression of CK18 in keratocyst epithelial linings transfers from basal cell layer to spinous layer. The expression of CK18 immunohistochemical staining and CK18 mRNA in situ hybridization are different, which shows CK18 might be related to proliferation of OKC epithelial linings. That suggests the existence of regulation of CK18 and CK18 mRNA expression.