细胞角蛋白19和间隙连接蛋白43在4-亚基硝氧喹啉诱发大鼠舌黏膜癌变过程中表达的研究

摘要

目的 研究4-亚基硝氧喹啉(4NQO)诱发大鼠口腔黏膜癌变过程中细胞角蛋白19(CK19)和间隙连接蛋白43(Cx43)的表达,探讨口腔黏膜癌变过程中CK19与Cx43的相关性.方法 利用4NQO诱导SD大鼠的口腔黏膜癌变,运用免疫组织化学的方法检测CK19、Cx43在口腔黏膜癌变过程中各阶段的动态变化.结果 在大鼠正常舌黏膜组织中,CKI9阳性染色的细胞散在分布于黏膜基底层；随着大鼠舌黏膜上皮异常增生程度的增加,CK19表达于黏膜基底上层；在口腔鳞状细胞癌(OSCC)组织中,CK19阳性染色细胞分布在黏膜各层.CK19在正常舌黏膜、轻度上皮异常增生、中度上皮异常增生、重度上皮异常增生、OSCC组织中阳性表达率分别为30.00％、50.00％、58.33％、80.00％、91.67％,差异有统计学意义(P＜0.05).在正常舌黏膜中Cx43蛋白主要表达于大鼠舌黏膜上皮细胞的细胞膜上,上皮的基底层、棘层和颗粒层呈阳性染色.随着大鼠舌黏膜上皮异常增生程度的增加,Cx43的表达明显下降.Cx43在正常舌黏膜、轻度上皮异常增生、中度上皮异常增生、重度上皮异常增生、OSCC组织中阳性表达率分别为100.00％、85.71％、66.67％、40.00％、33.33％,差异有统计学意义(P＜0.05).结论 在大鼠舌黏膜癌变过程中,CK19蛋白表达水平随病变程度加重显著升高,提示CK19与口腔上皮细胞的癌变有关；Cx43蛋白表达水平随病变程度加重显著下降,Cx43表达下降是口腔黏膜癌变的早期事件.CK19与Cx43蛋白表达呈负相关,CK19和Cx43的联合检测对OSCC的早期诊断有重要的作用,有利于提高OSCC早期诊断的灵敏度和特异性.%Objective To evaluate the expression of cytokeratin 19(CK19) and connexin 43(Cx43) in various stages of oral carcinogenesis and investigate the relationship of CK19 and Cx43 in the process of oral cancer.Methods 4-nitroquinoline-1-oxide(4NQO) was used to induce oral carcinogenesis in the mucosa of SD rats and immunohistochemical technique was used to study the expression of CK19 and Cx43 in various stages of oral carcinogenesis.Results The CK19 positive staining were distributed in the basal cell layer in the normal rat lingual mucosa.While CK19 positive staining were distributed in cytoplasm of supra-basal layers in the mild dysplasia,moderate dysplasia and severe dysplasia.In oral squamous cell carcinoma(OSCC) tissue,CK19 were expressed in all the stratum of epithelium.The positive rate of CK19 in normal,mild,moderate,severe dysplasia and OSCC tissues were respectively 30.00％,50.00％,58.33％,80.00％,and 91.67％.With the lesions getting worse,the positive rate and the intensity of CK19 raised significantly (P＜0.05).In normal tongue mucosa,Cx43 proteins were mainly expressed in the membrane of the epithelial cells of the rat tongue.It was weakly positive in the basal cell layer,increased in the stratum spinosum and stratum granulosum,and negative in the stratum corneum.Compared with normal epithelia,the expression of Cx43 in dysplastic and OSCC epithelia decreased significantly.The positive rate of Cx43 in normal,mild,moderate,severe dysplasia and OSCC tissues were respectively 100.00％,85.71％,66.67％,40.00％,and 33.33％.The expression of Cx43 was significantly decreased with severity increasing (P＜0.05).Conclusion The expression of CK19 protein significantly increases with the development of rat tongue carcinoma,suggesting that CK19 is associated with carcinogenesis.The expression of Cx43 protein dramatically decrease with the development of rat tongue carcinoma,suggesting that the abnormal expression of Cx43 protein is associated with oral mucosa carcinoma origination.The expression of CK19 and Cx43 has negative correlation.Combined detection of CK19 and Cx43 has an important role in the early diagnosis of OSCC and can help to improve the sensitivity and specificity of the early diagnosis of 0SCC.