细胞角蛋白18和13在术后性上颌囊肿化生上皮中的表达

目的研究口腔术后性颌骨囊肿（POMC）化生上皮起源以及细胞角蛋白（CK）在鳞状化生细胞中的表达.方法采用免疫组化SP法、原位杂交法和RT-PCR法,分别检测46例POMC中细胞角蛋白的表达情况.其中13例囊肿衬里上皮只含有假复层纤毛柱状上皮细胞;30例囊肿衬里既含有纤毛柱状上皮细胞,又含化生的鳞状上皮细胞;3例囊肿衬里只含有化生的鳞状上皮细胞.结果43例纤毛柱状上皮细胞中,39例表达CK8,9例表达CK13,43例均有CK18表达.发生鳞状上皮化生的细胞中CK13表达较多,CK8和CK18表达较少.在33例发生化生的囊肿衬里中,24例表达CK8,23例表达CK13,26例表达CK18.CK13和CK18蛋白的表达与CK13、CK18-mRNA表达水平相关.原位杂交方法检测CK1g-mRNA表达时发现,26例CK18蛋白阳性的化生囊肿衬里上皮以及7例发生化生但不表达CK18蛋白的囊肿衬里上皮都有CK18-mRNA的表达.RT-PCR结果进一步证明所有发生鳞状化生的囊肿衬里上皮都有CK18-mRNA的表达,但是其表达水平较未发生化生的柱状细胞囊肿衬里上皮弱,而且CK13-mRNA的表达与CK18-mRNA表达相反.结论在发生上皮化生的全过程中,CK18-mRNA保持不变,但是其蛋白的表达水平下降,而且发生鳞状化生时CK18表达减少,CK13表达增加.

Cytokeratin18,13 and their gene expression in post-operative maxillary cyst linings with metaplastic epithelium

Objective To study the cytokeratin 18 and 13 and their gene (CK) expression in post-operation maxillary cyst linings with metaplastic epithelium. Methods CK expressions were examined with immunohistochemistry in 46 post-operative maxillary cyst (POMC) which were lined with pseudostriated columnar cells only(13 cases), both kinds of columnar and squamous cells (30 cases)and squamous cells only (3 cases). Results The expressions of CK8, CK13 and CK18 were observed in 39, 9 and all of the 43 columnar epithelial linings, respectively. Metaplastic squamous epithelia expressed more CK13 and less CK18 and CK8. Of the 33 metaplastic linings, 24 expressed CK8, 23 CK13 and 26 linings expressed CK18. The expression of CK13- and CK18-mRNA was generally correlated with the protein expression level. By in situ hybridization, CK18-mRNA expression was observed not only in 26 metaplastic linings which were positive for CK18 protein but also in five of the seven metaplastic linings which did not express CK18 protein. In addition, RT-PCR revealed an expression of CK18-mRNA in all metaplastic squamous linings although the expression level was weaker than that in the columnar epithelial linings. The CK13-mRNA was expressed in a fashion inverse to the CK18-mRNA.Conclusions These results indicate that CK18-mRNA is preserved through metaplasia although the protein expression decreases and metaplastic squamous cells differentiate with a decrease of CK18 and an increase of CK13 expression.