The Expression And Significance Of Pten And COX-2in Different Types Of Colorectal Polyps

Purpose:To determine the expression of cancer gene COX-2, tumor-suppressor genePTEN in colonic polyps, and the relationship between the expressions anddifferent colonic polyps types, location, size, and whether or not multiple, andthe relations between each other, and to provide theory support for theoccurrence, development, diagnosis, prognosis, turned over of colonic polyps.Methods:60patients with colonic polyps were enrolled into the study and30healthypeople were selected for controls. Tissues from polyps, parapolyps (5cm abovethe polyps) in patients and tissues from sigmoid colon in healthy controls wereobtained under colonoscopy were confirmed by pathology and classification.Immunohistochemistry was used to determine the PTEN and COX-2in the threetissues. Further, analyze the correlation between the expression of PTEN andCOX-2and different pathological type, the site, size, and number of polyps.Results:1、 The expression of PTEN (48.3%) was significantly decreased in colonicpolyps than tissues besides polyps （63.3%） and normal colorectal mucousmembrane (66.7%). There was a significant difference between the three types(P=0.025). Between different pathological types, the expression of PTEN inadenoma (32.3%) was significantly lower than hyperplastic polyps（66.7%）andinflammatory polyps (64.3%). The positive expression rates of PTEN inadenoma were10%for villous adenoma,50%for mixed adenoma and70%fortubular adenoma. Furthermore, there was a significant difference between thethree types (p=0.015). 2、 The expression of COX-2was significantly increased in colonic polyps(80%) than tissues besides polyps (68.3%) and normal colorectal mucousmembrane (60%). There was a significant difference between the three types(P=0.02). Between different pathological types, the expression of COX-2inadenoma (90.3%) was significantly higher than hyperplastic polyps (60.0%) andinflammatory polyps (78.6%). The positive expression rates of COX-2inadenoma were100%for villous adenoma,90%for mixed adenoma and70%fortubular adenoma. Furthermore, there was a significant difference between thethree types (P=0.012).3、 In polyps tissues, the expression of PTEN and COX-2had a negativecorrelation (r=-0.588, P <0.001).4、 No difference of the expression of PTEN and COX-2was observedbetween polyps location, size, and whether or not multiple (P>0.05).Conclusion：The expression of PTEN was significantly decreased, or lack in polypstissues, especially in adenomas which shows a missing tendency. The expressionof PTEN varies between different adenoma pathologic types. Contrarily, theexpression of COX-2was significantly increased in polyp tissues, especially inadenoma and varies between different adenoma pathologic types. Besides, theexpression of PTEN and COX-2in colonic polyps tissues showed negativecorrelations. There might be interaction between them, which has importantvalue for the diagnosis, treatment and prognosis.