Zeng Xin, Chen Qianming, Nie Minhai
Department of Oral Medicine, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2003 Aug;21(4):259-62.
The purpose of the study is to investigate the mechanism of immune escape and the expression of Fas and Fas L in oral premalignant lesions (OPLs) and oral squamous cell carcinomas (OSCCs).
64 samples, including normal oral mucosa(7), hyperkeratosis(9), premalignant lesions(24) and squamous cell carcinomas(24), were studied. The cells in the test specimens, which demonstrate granular staining, were considered as positive. The expression of Fas and Fas L was evaluated semi-quantitatively as follows: -, no expression; + (mild), < 5% positive cells; ++ (moderate), 6%-25% positive cells; +++ (intense), 26%-50% positive cells; or ++++ (very intense), > 50% positive cells.
In the process of oral carcinogenesis, each stage had Fas expression. The positive staining appeared essentially on cell membrane. Various degrees of Fas expression were seen in the diseased tissues. The number of positively stained cells in the moderately and severely dysplastic tissues appeared higher than that in the normal control (P < 0.05). In the OSCC group, the level of expression of Fas antigen decreased significantly by comparison with the normal controls (P < 0.05). Fas L expression was discovered in each stage of the process of oral carcinogenesis. The positive staining appeared in cytoplasm. In hyperkeratotic tissues and OPLs, the number of Fas L expression cells was significantly higher than that in the normal controls. The number of Fas L expression cells of OSCCs increased by comparison with both normal controls and OPLs.
The results indicate that the expression of Fas and Fas L is involved in oral carcinogenesis and this may be directly related to the mechanism by which the cancer cells evade the host immune assault. Perhaps, Fas/Fas L system may be used as a prognostic biomarker in predicting the behavior of oral premalignant lesions in the near future.
本研究旨在探讨口腔癌前病变（OPL）和口腔鳞状细胞癌（OSCC）中免疫逃逸机制以及Fas和Fas L的表达情况。
对64份样本进行研究，包括正常口腔黏膜（7份）、角化过度（9份）、癌前病变（24份）和鳞状细胞癌（24份）。测试标本中显示颗粒状染色的细胞被视为阳性。Fas和Fas L的表达进行半定量评估如下： - ，无表达； +（轻度），<5%阳性细胞； ++（中度），6%-25%阳性细胞； +++（强阳性），26%-50%阳性细胞；或++++（极强阳性），>50%阳性细胞。
在口腔癌发生过程中，各阶段均有Fas表达。阳性染色主要出现在细胞膜上。病变组织中可见不同程度的Fas表达。中度和重度发育异常组织中阳性染色细胞数量高于正常对照（P<0.05）。在OSCC组中，与正常对照相比，Fas抗原表达水平显著降低（P<0.05）。在口腔癌发生过程的各阶段均发现Fas L表达。阳性染色出现在细胞质中。在角化过度组织和OPL中，Fas L表达细胞数量显著高于正常对照。OSCC的Fas L表达细胞数量与正常对照和OPL相比均增加。
结果表明，Fas和Fas L的表达参与口腔癌发生，这可能与癌细胞逃避宿主免疫攻击的机制直接相关。也许，Fas/Fas L系统在不久的将来可作为预测口腔癌前病变行为的预后生物标志物。
