生长抑素受体在结直肠癌和正常黏膜表达及与细胞增殖和凋亡的关系

目的:研究生长抑素受体 (SSTR)在结直肠癌和相应正常黏膜中的表达以及与临床病理的关系,指导临床结直肠癌病人应用生长抑素及其类似物治疗. 方法:应用免疫组化法分别检测42例结直肠癌及其附近正常黏膜生长抑素受体,并同时检测细胞凋亡指数和增殖指数. 结果:免疫组化结果表明,结直肠癌中生长抑素受体蛋白表达率为83.3%(35/42),正常黏膜为92.9%(39/42),<0.001,表达阳性率差异无显著性意义,但表达强度差异明显,结直肠癌生长抑素受体表达明显低于正常黏膜,生长抑素受体表达阴性或弱阳性的肿瘤,相应的正常黏膜生长抑素受体表达中等强度或强阳性,而生长抑素受体中等强度阳性或强阳性表达的肿瘤,相应的正常黏膜均呈强阳性表达.而且不同表达强度的结直肠癌增殖指数和凋亡指数差异有显著性意义(P<0.001,P<0.001).生长抑素受体的表达强度与肿瘤病理分期、分化程度相关(P<0.001,<0.001),与病人年龄、性别、肿瘤大小无显著相关性(P=0.682,P=0.789,P=0.342). 结论:生长抑素受体在结直肠癌中有阳性表达,但表达强度明显低于相应正常黏膜.

Expression of somatostatin receptor in human colorectal cancers and normal mucous tissues

Objectives: The study was designed to determinate whether human colorectal cancers (CRC) would express somatostatin receptor and whether somatostatin could be used in human CRC. Methods: Forty-two specimens of CRC and normal colorectal mucous membrane were taken in patients who suffered CRC. Immunohistochemistry (IHC) technique was used to demonstrate somatostatin receptor expressions. The relationship between expression of SSTR and clinical or pathological factors was analyzed. The expression of SSTR,proliferative index (PI) and apoptosis index (AI) of the CRC were measured. Results: SSTR was expressed in human CRC(35/42, 83.3%) and the normal mucous tissue (39/42, 92.9%, P< 0.001 ). Sharply contrasting with SSTR-negative tumors, the normal colorectal mucous membrane was positive. A significant correlation was found between SSTR expression and tumor stage (P<0.001) and tumor differentiation (P<0.001). And there was no statistically significant relationship between the expression of SSTR and the age, gender of patients and the tumor size (P=0.682, P=0.789, P= 0.342 ). Conclusions: Somatostatin receptor is expressed in human colorectal cancer and appears to be down-regulated compared to the normal mucous tissue. Somatostatin and its analogues can be used in colorectal cancer cases which express somatostatin receptor proteins.