GAS、COX-2在结直肠腺瘤及恶变中表达及意义

Expression and Signi cance of Gastrin and Cyclooxygenase-2 in Adenomas and Malignant Transformation of Colorectal adenomas

目的探索GAS、COX-2在结肠腺瘤性息肉生长、分化以及恶变之间的表达及意义。方法回顾性收集2003年6月～2006年6月间行结肠镜下切除、外科手术和取病理活检的68例息肉及20例大肠癌标本。通过免疫组化染色,观察不同组织学类型、不同异型增殖程度以及恶变时息肉中GAS、COX-2和Ki-67的表达情况,并与10例正常结肠粘膜标本进行比较。所有患者均无家族性腺瘤性息肉病史,均未长期服用过非甾体抗炎药(NSAIDs)、质子泵抑制剂或糖皮质激素。结果GAS、COX-2在正常肠粘膜及非腺瘤息肉中呈弱阳性表达或不表达,在绒毛腺瘤、腺瘤局部恶变及结肠癌中表达分别为543.7±228.9,683.7±356.8,722.5±356.7和228.6±24.0,232.4±26.3,232.9±27.0。在重度异型增生时的表达分别为498.8±339.3和228.9±13.6,与其他组比较差异有显著性(P<0.05)。COX-2的阳性表达与GAS表达成正相关(r=0.67,P<0.01)。Ki-67表达在GAS或COX-2阳性表达时增高,特别在GAS和COX-2共同表达时增加明显。结论GAS、COX-2的表达与息肉组织的组织类型、增生程度和息肉恶变密切相关,在结直肠腺瘤性息肉发生、发展及恶变中过程中扮演重要的角色,可能具有促进腺瘤向腺癌转变的作用。

Objective： To investigate the correlation between expressions of gastrin and cyclooxygenase-2 and proliferation, differentiation and malignant transformation of colorectal adenomas. Methods： Gastrin, Cyclooxygenase-2 and Ki-67 expressions were examined by immunohistochemical staining in 68 colorectal adenoma, 20 colorectal cancer, 10 normal colonic mucosal tissues that had been obtained by endoscopic biopsy, surgical resection and endoscopic polypectomy between June 2003 and June 2006. Those patients associated with inflammatory bowel disease, familial polyposis coli or those having a history of taking non-steroidal anti-inflammatory drugs（including low-dose aspirin）, glucocorticoid and proton pump inhibitors were excluded. Results： Expressions of gastrin and Cyclooxygenase-2 were higher significantly in the adenomas than those in the normal control groups（P〈0.05）, the expressions ofgastrin is 543.7 ± 228.9, 498.8 ±339.3,683.7 ± 356.8, 722.5 ± 356.7; and of COX-2 is 228.6± 24.0, 228.9 ± 13.6,232.4 ± 26.3, 232.9 ± 27.0 in villous adenomas, sever dysplasia ,polyps with malignant transformation and eolorectal cancer, respectively. Correlation analysis showed that there was significant positive correlation between COX-2 and gastrin expressions （r = 0.67, P〈0.01 ） . The Ki-67 expression was significantly higher in patients with both gastrin and Cyelooxygenase-2 expression than in patients without gastrin or Cyclooxygenase-2 expression （P〈0.01）. Conclusion： These results suggest that increased gastrin and Cyclooxygenase-2 expression may be related to growth and malignant transformation of adenomas, and play an important role in the progression of colorectal adenoma. Gastrin may induce Cyclooxygenase-2 expression and co-stimulate cell proliferation in the growth and malignant transformation of adenomas.