甲基化组蛋白H3K27m在结直肠癌及其癌前病变中的表达

Expression of methylated histone H3K27m in colorectal cancer and its precancerous lesion

目的 通过检测甲基化组蛋白H3K27m在结直肠正常组织、低高级别异型增生、高中低分化腺癌中的表达,探讨其表达与结直肠腺癌发生发展过程的相关性,为结直肠癌的临床早期诊断提供候选标识分子。方法 收集结直肠正常组织、低级别异型增生、高级别异型增生、高分化腺癌、中分化腺癌、和低分化腺癌组织各30例采用免疫组织化学染色法检测结直肠病变组织中甲基化组蛋白H3K27m的表达,并结合临床病理资料进行比较分析。结果 H3K27m在结直肠癌正常组织、低级别异型增生、高级别异型增生、高分化腺癌、中分化腺癌、低分化腺癌组织中的阳性表达率分别为0、3.3%、16.7%、36.7%、43.3%和43.3%。组蛋白H3K27m在正常的结直肠组织与结直肠的低级别异型增生、高级别异型增生中的表达无统计学差异(P>0.05),但与分化型腺癌(包括高、中、低分化腺癌)有统计学差异(P<0.05)。结论 甲基化组蛋白H3K27m在结直肠不同程度病变组织中存在差异表达,提示该基因参与了结直肠癌的发生发展过程,可用于判定结直肠病变的转归和预测。

Objective To explore the correlation between expression of H3K27m in colorectal tissues and development of colorectal adenocarcinoma with different degrees, by detecting the expression of H3K27m in normal colorectal tissues, low-and high-grade dysplasia, well-, moderately-and poorly-differentiated adenocarcinoma, to provide a candidate marker for early diagnosis of colorectal cancer. Methods Normal colorectal tissues, low-grade dysplasia, high-grade dysplasia, well differentiated adenocarcinoma, moderately differentiated adenocarcinoma, and poorly differentiated adenocarcinoma were collected, respectively, a total of 180 cases. The expression of H3K27m in colorectal lesions was detected by immunohistochemical staining, and compared with clinicopathological data. Results The positive expression rates of H3K27m in normal colorectal tissues, low-grade dysplasia, high-grade dysplasia, well-differentiated adenocarcinoma, moderately-differentiated adenocarcinoma and poorly-differentiated adenocarcinoma were 0, 3.3%, 16.7%, 36.7%, 43.3%, and 43.3%, respectively. The difference of H3K27m did not occur between the normal colorectal tissues and low-grade dysplasia or high-grade dysplasia(P>0.05);however, the difference between normal colorectal tissues and differentiated adenocarcinomas(including well-, moderately-, poorly-differentiated adenocarcinomas) was statistically significant(P<0.05). Conclusion Differential expression of methylated histone H3K27m in different degrees of colorectal lesions suggests that this gene is involved in the occurrence and development of colorectal cancer and can be used to determine the outcome of colorectal lesions and the prediction of patients.