PTEN及P-ERK和P-AKT在中耳胆脂瘤上皮中的表达及意义

Expression and significance of PTEN,P-ERK and P-AKT in the middle ear cholesteatoma

目的:检测蛋白酪氨酸磷酸酶基因(PTEN)、磷酸化蛋白激酶B(P-AKT)和磷酸化细胞外信号调节激酶(P-ERK)在人类中耳胆脂瘤上皮的表达情况及其相关性,探讨它们在中耳胆脂瘤形成机制中的重要作用。方法:应用免疫组织化学SABC法检测40例中耳胆脂瘤标本及15例正常皮肤标本中PTEN、P-AKT和P-ERK蛋白的表达量及定位。应用Western blot免疫印迹法检测其中20例中耳胆脂瘤标本和10例正常皮肤标本PTEN、P-AKT和P-ERK蛋白以及内参GAPDH的表达量。结果:①免疫组织化学显示,PTEN在胆脂瘤和正常皮肤中的细胞核及胞质均有着色。核PTEN在胆脂瘤的阳性表达率明显低于正常皮肤,两者差异具有统计学意义(P<0.01);质PTEN在胆脂瘤的阳性表达率明显低于正常皮肤,两者差异具有统计学意义(P<0.01);PAKT主要在细胞质着色,胆脂瘤中的阳性表达率明显高于正常皮肤,两者差异具有统计学意义(P<0.01);PERK主要在细胞核着色,胆脂瘤中的阳性表达率明显高于正常皮肤,两者差异亦具有统计学意义(P<0.01)。在中耳胆脂瘤标本中,PTEN分别与P-AKT、P-ERK蛋白的表达之间呈显著负相关(P<0.01)。②Western blot免疫印迹法检测显示:胆脂瘤中PTEN的表达量明显少于正常皮肤中的表达量;而P-AKT和P-ERK在胆脂瘤中的表达量明显多于它们在正常皮肤中的表达量。结论:PTEN、P-AKT和P-ERK蛋白在中耳胆脂瘤中的异常表达可能与胆脂瘤上皮的高度增殖和抗凋亡密切相关。PTEN表达缺失导致其抑制作用减弱,一方面使P-AKT表达过度,继而引起胆脂瘤上皮细胞凋亡受抑制;同时也使P-ERK表达过度,导致胆脂瘤上皮细胞增殖加强。

Objective：Detect the expressions of the protein tyrosine phosphatase gene（PTEN）, phosphoryla- ted protein kinase B（P-AKT） and phosphorylated extracellular signal-regulated kinase（P-ERK） in human middle ear cholesteatoma tissue and its correlation to explore their important role in the mechanism of the formation of cholesteatoma. Method：Use immunohistochemical SABC method （SABC immunohistochemical method） to detect the expressions and location of PTEN, P-AKT and P-ERK proteins in 40 cases of middle ear cholesteatoma tissue samples and 15 cases of normal ear skin specimens. Use Western blot to detect the expression levels of PTEN, P-AKT,P-ERK proteins and the internal reference GAPDH in 20 cases of cholesteatoma tissue and 10 cases in nor-mal ear skin specimens. Result：①lmmunohistochemistry showed coloring of PTEN both in the nucleus and cyto- plasm of cholesteatoma and normal skin. Nuclear PTEN positive expression rates in the cholesteatoma was signif-icantly lower than normal skin,and the difference was significant（P〈0.01） ;cytoplasm PTEN positive expression rates in the cholesteatoma was significantly lower than normal skin,and the difference was significant（P〈0.01）;P-AKT mainly expresses in the cytoplasm of cholesteatoma and normal skin. The positive expression rates in the cholesteatoma was significantly higher than normal skin, and the difference was significant（P^0.01） ~ the P- ERK mainly colors in cholesteatoma and normal skin cell nucleus, the positive expression rates in the cholesteatoma was significantly higher than normal skin,and the difference was significant （P〈0.01）. In cholesteatoma specimens, there was a significantly negative relationship（P〈0.01）between PTEN, respectively, and P-AKT, P-ERK pro-tein. ②Western blot discovered： the expression of PTEN in cholesteatoma was significantly less than the amount of expression in normal skin; P-AKT and P-ERK expression in cholesteatoma was significantly more than the leve lin normal skin. Conelasion：Abnormal expression of PTEN, P-AKT and P-ERK protein in cholesteatoma may be closely related to antiapoptosis and high degree of proliferation in cholesteatoma. Expression of PTEN deletion leads to the weakening of the inhibition. Excessive expression of P-AKT gives rise to cholesteatoma epithelial cell apoptosis inhibited; excessive P-ERK expression result to cholesteatoma epithelial cell proliferation strengthened.