PTEN和Cdx2在溃疡性结肠炎和结直肠癌中的表达

Expressions of PTEN and Cdx2 in Ulcerative Colitis and Colorectal Cancer

背景:PTEN具有磷酸酶活性,能调控细胞的增殖、迁移和凋亡。Cdx2是一种肠道特异性转录因子,在调节肠上皮细胞分化、增殖中起关键作用。近年溃疡性结肠炎(UC)与结直肠癌之间的关系日益受到关注。目的:观察UC和结直肠癌组织中PTEN和Cdx2的表达,探讨两者在UC癌变进程中的作用。方法:在上海瑞金医院1997年1月～2007年10月诊断的UC患者中收集经病理检查确诊者的蜡块标本,其中UC组17例,UC相关结直肠癌组7例,另收集非UC相关结直肠癌标本35例和正常肠黏膜标本15例,以免疫组化方法检测PTEN和Cdx2表达。结果:PTEN和Cdx2在正常结直肠组织中基本呈阳性表达,阳性率分别为93.3%和100%,UC组织两者表达阳性率显著降低,均仅为6.7%。UC相关结直肠癌组PTEN和Cdx2表达阳性率显著低于非UC相关结直肠癌组(PTEN:28.6%对83.9%,Cdx2:42.9%对90.3%,P<0.01)。结论:UC与结直肠癌之间可能存在相关性。PTEN和Cdx2在调控肠上皮分化、增殖的过程中可能有相似的调节点或具有协同作用,两者可能共同参与了对UC癌变进程的调控。

Background： PTEN has phosphatase activity and can modulate cell proliferation, migration and apoptosis. Cdx2 is a specific intestinal transcription factor and plays a key role in modulating the differentiation and proliferation of intestinal epithelial cells. Studies on the relation between ulcerative colitis （UC） and colorectal cancer have received more attention in recent years. Aims： To deiermine the expressions of PTEN and Cdx2 in UC and colorectal cancer tissues, so as to investigate their roles in the malignant transformation of UC lesions. Methods： Paraffin blocks of biopsy specimens of UC patients diagnosed pathologically in Shanghai Ruijin Hospital from Jan. 1997 to Oct. 2007 were collected, among them 17 cases were of the UC group and 7 cases were of the UC-related colorectal cancer group. Thirty-five non-UC-related colorectal cancer and 15 normal colorectal mucosal tissues were also collected. The expressions of PTEN and Cdx2 were determined by immunohistochemistry. Results： PTEN and Cdx2 expressed in most of the normal colorectal mucosal tissues （93.3% and 100%, respectively）, but decreased significantly in UC tissues （6.7% and 6.7%, respectively）. The expressions of PTEN and Cdx2 in UC-related colorectal cancer were significantly lower than those in non-UC-related colorectal cancer （FYEN： 28.6% vs. 83.9%, Cdx2： 42.9% vs. 90.3%, P〈0.01）. Conclusions： UC might be correlated with colorectal cancer. PTEN and Cdx2 may have similar accommodative point in regulating the differentiation and proliferation of intestinal epithelium, and the two conjointly participate in the modulation of malignant transformation of UC lesions.