中文摘要：

目的：明确口腔鳞癌组织和细胞中黏液素样细胞表面黏附分子CD24的表达模式、作用及其作为治疗靶点的潜在价值。方法：利用免疫组化、real-time RT-PCR和Western blot方法,明确CD24在78例人口腔组织标本和59例动物模型金地鼠（Hamster buccal）颊囊组织标本,以及口腔癌前病变上皮细胞DOK4、口腔鳞癌细胞CAL-27和WSU-HN6中的表达模式;以CAL-27和WSU-HN6细胞为模型,明确在常规和无血清成球培养条件下,全反式维甲酸（all-trans retinoic acid,ATRA）和CD24抗体对CAL-27和WSU-HN6细胞及肿瘤球生长的影响,并观察它们是否影响这两种细胞中CD24的表达。结果：人和金地鼠组织的免疫组织染色结果显示,在正常/单纯增生组织、轻度/中度异常增生组织、重度异常增生和鳞癌组织中均依次呈现CD24表达递增的现象（P〈0.05）;与DOK细胞相比较,CAL-27和WSU-HN6口腔鳞癌细胞中CD24表达上调（P〈0.05）。相对于癌前病变细胞DOK,口腔鳞癌细胞CAL-27和WSU-HN6具有更强的增殖和肿瘤球成球的潜能（P〈0.05）。ATRA能够有效地抑制这两种口腔鳞癌细胞的CD24表达、体外增殖和肿瘤球形成的能力（P〈0.05）,而CD24抗体虽然也一样能够抑制口腔鳞癌细胞的增殖和肿瘤球形成（P〈0.05）,但却不影响其CD24的表达。结论：CD24在口腔鳞癌中表达上调,具有促进口腔鳞癌细胞增殖和肿瘤球形成的作用,维甲酸和CD24抗体皆能以CD24为靶点有效地抑制口腔鳞癌细胞的增殖和肿瘤球形成。

英文摘要：

Objective：To determine the expression profile and potential roles of CD24 in oral squamous cell carcinoma and explore the values of CD24 function as a potential target of clinical therapy. Me- thods： Semi-quantitative immunohistochemistry was used to construct the expression profile of CD24 in 78 human oral tissues and 59 Hamster buccal pouch tissues. Real-time RT-PCR and Western blot were used to analyze the CD24 expression levels in oral DOK4 cells, oral cancer CAL-27 and WSU-HN6 cells. Then these two cancer cell lines were selected to evaluate the effect of all-trans retinoic acid （ATRA） and CD24 antibody on CD24 expression, and the proliferation and tumorsphere formation capacity of these two cell lines. Results： CD24 expression was found significantly elevated in both human and animal tissues compared with normal and benign tissues （ P 〈 0.05 ） , as well as in oral cancer CAL-27 and WSU-HN6 cells compared with DOK cells （P 〈 0.05 ）. CAL-27 and WSU-HN6 cells possess increased proliferative and specific tumorsphere formation capability compared with DOK cells （ P 〈 0.05 ）. Both ATRA and CD24 antibody were able to effectively inhibit the proliferation and tumorsphere formation of CAL-27 and WSU-HN6 cells （P 〈 0.05 ）. Among them ATRA at least involved partially in the proliferation by down- regulating the CD24 expression （ P 〈 0.05 ） , while CD24 antibody blocking had no effect on the CD24 expression. Conclusion： CD24 was upregulated in oral cancer and functioned as a potential factor that promoted the proliferation and tumorsphere formation of CAL-27 and WSU-HN6 cells. Both ATRA and CD24 antibody might effectively inhibit the proliferation and tumorsphere formation of CAL-27 and WSU- HN6 cells and function as a potential therapy target.