He Dan, Xiao Lin, Chen Jian-Ning, Liang Qiong, Shao Chun-Kui
Department of Pathology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510630, P.R. China.
Chin J Cancer. 2010 Mar;29(3):283-7. doi: 10.5732/cjc.009.10260.
Epstein-Barr virus (EBV) has been detected in about 10% of gastric carcinomas. However, the pathogenetic role of EBV in gastric carcinoma is uncertain. This study was to explore the correlation of Fas/FasL expression to the apoptosis of tumor cells and tumor-infiltrating lymphocytes (TIL) in EBV-associated gastric carcinoma (EBVaGC).
Fas/FasL expression in 49 specimens of EBVaGC, 20 specimens of EBV-negative gastric carcinoma (EBVnGC) and 12 specimens of normal gastric mucosa was detected by immunohistochemistry. The apoptotic index (AI) of cells was determined by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL).
The positive rates of Fas were 91.7% in normal gastric mucosa and 76.8% in gastric carcinoma (P < 0.05); those of FasL were 16.7% in normal gastric mucosa and 58% in gastric carcinoma (P < 0.05). The positive rate of Fas was significantly lower in EBVaGC than in EBVnGC (71.4% vs. 90.0%, P < 0.05). The positive rate of FasL in EBVaGC was significantly higher than that in EBVnGC (63.2% vs. 45%, P < 0.05). The AI of EBVaGC cells was significantly lower than that of EBVnGC cells (P = 0.002). The number and AI of TIL in EBVaGC were higher than those in EBVnGC (P < 0.05). The AI of TIL was positively correlated with the level of FasL expression in tumor cells (r=0.237, P = 0.028).
Up-regulation of FasL expression and decrease of TIL apoptosis in EBVaGC may facilitate the escape of tumor cells from the host immunosurveillance, and it might contribute to the development and progression of carcinoma.
在约10%的胃癌中检测到爱泼斯坦-巴尔病毒（EBV）。然而，EBV在胃癌中的致病作用尚不确定。本研究旨在探讨Fas/FasL表达与EB病毒相关胃癌（EBVaGC）中肿瘤细胞及肿瘤浸润淋巴细胞（TIL）凋亡的相关性。
采用免疫组织化学法检测49例EBVaGC标本、20例EBV阴性胃癌（EBVnGC）标本及12例正常胃黏膜标本中Fas/FasL的表达。采用末端脱氧核苷酸转移酶（TdT）介导的dUTP-生物素缺口末端标记法（TUNEL）测定细胞凋亡指数（AI）。
Fas在正常胃黏膜中的阳性率为91.7%，在胃癌中的阳性率为76.8%（P<0.05）；FasL在正常胃黏膜中的阳性率为16.7%，在胃癌中的阳性率为58%（P<0.05）。EBVaGC中Fas的阳性率显著低于EBVnGC（71.4%对90.0%，P<0.05）。EBVaGC中FasL的阳性率显著高于EBVnGC（63.2%对45%，P<0.05）。EBVaGC细胞的AI显著低于EBVnGC细胞（P=0.002）。EBVaGC中TIL的数量和AI高于EBVnGC（P<0.05）。TIL的AI与肿瘤细胞中FasL表达水平呈正相关（r=0.237，P=0.028）。
EBVaGC中FasL表达上调及TIL凋亡减少可能促进肿瘤细胞逃避宿主免疫监视，可能有助于肿瘤的发生发展。
