摘要目的 探讨角化棘皮瘤(KA)与皮肤鳞状细胞癌(SCC)在细胞凋亡方面的差异.方法 消退期角化棘皮瘤(rKA)、Ⅰ级皮肤鳞状细胞癌(wdSCC)及正常皮肤,每组标本各为30例.应用免疫组化法检测上述皮损中B细胞淋巴瘤/白血病-2蛋白(Bcl-2)、天冬氨酸特异性半胱氨酸蛋白酶-3(Caspase-3)、第二线粒体衍生的半胱天冬酶激活蛋白(Smac/DIABLO)及凋亡抑制蛋白Livin表达情况.结果 Bcl-2在rKA中的表达较正常皮肤明显减少(t=3.1572,P＜ 0.05).Caspase-3在rKA中的表达较wdSCC中明显减少(t=2.1364,P＜0.05).Smac/DIABLO在正常皮肤中高表达,rKA和wdSCC中表达降低,差异有统计学意义(t=7.6141,9.5666,P值均＜0.05).Livin在正常皮肤中不表达,rKA和wdSCC中表达增高,差异有统计学意义(t=4.7913,12.7737,P值均＜0.05).Livin在rKA中的表达较wdSCC明显减少(t=7.9824,P＜0.05).结论 细胞凋亡在KA的自然消退中起到某种作用.凋亡调控蛋白Caspase-3及Livin可能有助于鉴别rKA和wdSCC.

abstractsObjective To investigate the difference in cell apoptosis between keratoacanthoma and squamous cell carcinoma.Methods Ninety specimens were obtained from the lesions of 30 patients with regressing keratoacanthoma (rKA) and 30 patients with well-differentiated squamous cell carcinoma (wdSCC) as well as from the normal skin of 30 human controls.Immunohistochemistry was carried out to measure the expressions of B-cell leukemia/lymphoma 2 (Bcl-2),cysteine-aspartic acid protease (Caspase)-3,second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pl (Smac/DIABLO) and inhibitor of apoptosis protein Livin.Results The Bcl-2 protein expression was significantly lower in rKA specimens than in normal control specimens (t =3.1572,P ＜ 0.05).A lower expression of Caspase-3 protein was observed in rKA specimens compared with wdSCC specimens (t =2.1364,P ＜ 0.05).The expression of Smac/DIABLO protein was significantly increased in normal control specimens than in rKA and wdSCC specimens (t =7.6141,9.5666,respectively,both P ＜ 0.05).Livin was absent in normal skin,but highly expressed in rKA and wdSCC specimens,and the difference was significant between the normal skin and lesional (rKA and wdSCC) specimens ( t =4.7913,12.7737,respectively,both P ＜ 0.05).The expression of Livin protein was significantly reduced in rKA specimens than in wdSCC specimens (t =7.9824,P ＜ 0.05).Conclusions Cell apoptosis plays a certain role in the natural regression process of KA.The detection of apoptosis-regulating proteins Caspase-3 and Livin are beneficial for the differentiation between rKA and wdSCC.