MGMT蛋白在甲状腺癌中的表达及其临床意义

目的：探讨O6-甲基鸟嘌呤-DNA甲基转移酶（O6-methylguanine-DNA methyltransferase, MGMT）在甲状腺癌组织中的表达及其临床意义。方法：用免疫组织化学SP法检测61例甲状腺癌、21例甲状腺良性腺瘤、15例桥本氏甲状腺炎、8例结节性甲状腺肿和12例癌旁正常组织中MGMT蛋白的表达，并结合临床病理因素进行分析。结果：MGMT在甲状腺癌组织中的表达与正常组织中的表达差异有统计学意义（P＜0.05）。MGMT表达从正常组织（16.67%，10/12）、结节性甲状腺肿（25.00%，2/8）、桥本氏甲状腺炎（60.00%，9/15）、甲状腺腺瘤（52.38%，11/21）到甲状腺癌（60.66%，38/61）中表达水平基本呈上升趋势。在甲状腺乳头状癌与甲状腺滤泡癌的表达差异有统计学意义（P＜0.05），表达水平随甲状腺癌恶性程度的增加而降低，分别为乳头状癌（72.22%，26/36）、滤泡癌（50.00%，8/16）。MGMT在性别、年龄及民族组中表达差异均无统计学意义（P＞0.05）。结论：MGMT高表达现象可能与甲状腺癌恶性程度有关，可成为候选的临床分子诊断指标。甲状腺癌组织的MGMT蛋白在性别、年龄和民族组表达均无差异，有望成为通用的临床检测指标。

Expression of MGMT and its clinopathological significance in thyroid carcinoma

Objective To study the expression of O6-methylguanine-DNA methyltransferase (MGMT) and its clinicopathological significance in thyroid cancer.Methods Immunohistochemistry was used to determine the expression of MGMT in 61 thyroid cancer tissues, 21 thyroid adenomas, 15 Hashimoto's thyroiditis, 8 nodular goiter, and 12 peri-tumor tissues. Results There was statistic difference in the expression of MGMT between the normal tissues and thyroid cancers (P＜0.05). Expression of MGMT increased from the normal tissue (16.67%, 10/12), nodular goiter (25.00%, 2/8), Hashimoto's thyroiditis (60.00%, 9/15), and thyroid adenoma (52.38%, 11/21)to thyroid cancer (60.66%, 38/61). Expression of MGMT in papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC) had significant difference (P＜0.05), and the expression level of MGMT decreased with the malignancy of thyroid cancer, such as in PTC (72.22%, 26/36), and FTC (50.00%, 8/16). There was no statistic difference in MGMT expression in sex, age, and nationality (P＞0.05).Conclusion High expression of MGMT might be related to the malignancy of thyroid cancer, which may be one of the diagnosis indexes for thyroid cancer. It will be a common clinical index in diagnosingthyroid cancer since there is no difference in MGMT expression among sexes, ages, and nationalities.