Soini Y, Törmänen U, Pääkkö P
Department of Pathology, University of Oulu, Finland.
Histopathology. 1998 Jan;32(1):28-34. doi: 10.1046/j.1365-2559.1998.00334.x.
We investigated the extent of apoptosis in 55 benign and malignant salivary gland tumours and its association with the immunohistochemical expression of bcl-2 and bax.
Apoptosis was detected in histological sections by the 3'-end DNA labelling method. bcl-2 and bax protein expression was determined by immunohistochemistry. The frequency of apoptosis was clearly higher in malignant than in benign tumours. In pleomorphic adenomas and Warthin's tumours the average apoptotic index was 0.01% (range 0.00-0.07%) while in the malignant salivary gland tumours it was 0.42% (range 0.00-1.75%). Immunohistochemical bcl-2 expression was observed in all pleomorphic adenomas and Warthin's tumours and in most cases the expression was strong. In malignant tumours, 9/25 cases showed no expression and in the rest of the cases, apart from adenoid cystic carcinomas, the bcl-2 expression was often weak. There were significantly more cases with no or weak bcl-2 positivity in malignant than in benign salivary gland tumours (P = 0.001). There was a statistically significant association between a weak bcl-2 expression and a high frequency of apoptosis (P = 0.02). In contrast to bcl-2, strong bax expression was found in both benign and malignant tumours and was not associated with the frequency of apoptosis.
The low bcl-2 expression in malignant tumours suggests that down-regulation of its expression might contribute to their higher frequency of apoptosis.
我们研究了55例涎腺良恶性肿瘤中的细胞凋亡程度及其与bcl-2和bax免疫组化表达的关系。
采用3'-末端DNA标记法在组织切片中检测细胞凋亡。通过免疫组化测定bcl-2和bax蛋白表达。恶性肿瘤中的细胞凋亡频率明显高于良性肿瘤。在多形性腺瘤和沃辛瘤中，平均凋亡指数为0.01%（范围0.00 - 0.07%），而在涎腺恶性肿瘤中为0.42%（范围0.00 - 1.75%）。在所有多形性腺瘤和沃辛瘤中均观察到免疫组化bcl-2表达，且在大多数情况下表达较强。在恶性肿瘤中，25例中有9例无表达，在其余病例中，除腺样囊性癌外，bcl-2表达通常较弱。涎腺恶性肿瘤中bcl-2阳性缺失或弱阳性的病例明显多于良性肿瘤（P = 0.001）。bcl-2弱表达与高细胞凋亡频率之间存在统计学显著关联（P = 0.02）。与bcl-2相反，在良性和恶性肿瘤中均发现bax强表达，且与细胞凋亡频率无关。
恶性肿瘤中bcl-2低表达表明其表达下调可能导致其较高的细胞凋亡频率。
