直肠癌远端移形黏膜COX-2及BCL-2蛋白的表达与临床意义

目的探讨直肠癌远端移形黏膜COX-2及BCL-2蛋白的表达情况,判断直肠癌远端移形黏膜是否为癌前病变。方法应用高铁二胺-阿辛蓝染色检测54例直肠癌远端2cm处黏膜．将远端黏膜分为移形黏膜（TM）组及非移形黏膜（NTM）组,通过免疫组织化学染色检测TM中COX-2和BCL-2蛋白的表达．比较TM与NTM、肿瘤组织以及正常黏膜组织（20例直肠良性息肉旁肠黏膜组织）内BCL-2以及COX-2的表达的差异。结果54例直肠癌远端2cm黏膜处组织中有19例存在TM．35例为NTM。COX-2蛋白在肿瘤组织、TM、NTM、正常组织中的阳性率分别为81．5％（44／54）、21．1％（4／19）、17．1％（6／35）、10．0％（2／20）;BCL-2蛋白在上述4种组织中的阳性率分别为77．8％（42／54）、21．1％（4／19）、22．9％（8／35）、5．0％（1／20）。TM内的COX-2及BCL．2蛋白的表达与肿瘤组织相比,差异有统计学意义[（0．737±0．895）比（3．519±1．998）;（0．632±0．955）比（2．833±1．756）,均P〈0．01];与NTM、正常肠黏膜组织相比,差异无统计学意义（均P〉0．05）。结论直肠癌远端TM内的COX-2和BCL-2蛋白的表达无特异性．TM是癌前病变的证据不足。

Expression and clinical significance of COX-2 and BCL-2 in distal transitional mucosa adjacent to rectal carcinoma

Objective To investigate the expression of COX-2 and BCL-2 in transitional mucosa adjacent to rectal carcinoma, and to determine whether precursor event exists in the transitional mucosa. Methods Mucin histochemical method (HID/AB) was used to determine the distal mucosa 2 cm away from rectal carcinoma in 54 patients with rectal cancer. Immunohistochemical method was employed to detect the expression of BCL-2 and COX-2 in the rectal cancer specimen, transitional mucosa (TM), non-transitional mucosa (NTM), and 20 cases of normal rectal mucosa. Student's t-test and Chi-square test were preformed. Results Nineteen patients with positive TM were found. COX-2 expression was identified in 81.5% of cancer tissue, 21.1% of TM, 17.1% of NTM, and 10.0% in normal mucosa. BCL-2 protein was found in 77.8% of cancer tissue, 21.1% of TM, 22.9% of NTM, and 5.0% of normal mucosa. The expressions of COX-2 and BCL-2 in TM were significantly different from tumor tissue[(0.737±.0.895) versus (3.519±.1.998), and (0.632±.0.955) versus (2.833±.1.756), all P<0.01]. However, there were no significant differences between TM and NTM or normal mucosa.Conclusions Expressions of COX-2 and BCL-2 are non-specific in the transitional mucosa at the distal rectum. Evidence is not available in TM being precursor lesion.