MGMT在TSH腺瘤中的表达及临床意义

目的促甲状腺激素腺瘤(TSH腺瘤)约占垂体腺瘤总数的2%,一线的治疗方式是手术治疗,但手术治疗面临许多困难并且效果一般。有研究表明:TMZ的疗效和O-6甲基鸟嘌呤-DNA甲基转移酶(MGMT)密切相关。因此,本研究拟通过检测TSH腺瘤标本中MGMT的表达来评估TMZ对TSH腺瘤的治疗价值。方法本研究所用15例TSH腺瘤标本均来自南京军区南京总医院神经外科手术病例。采用SP免疫组织化学染色法检测15例TSH腺瘤中MGMT表达;在光镜下用半定量方法分析标本中阳性细胞核的表达情况来评分。结果本研究15例TSH腺瘤中女性8例,男性7例,平均年龄(53.2±15.9)岁。超过一半(53.3%)TSH腺瘤的MGMT表达25%,绝大多数(93.3%)TSH腺瘤的MGMT低表达(≤50%)。结论大部分TSH腺瘤低表达MGMT,可能适合TMZ治疗。

Expression of O-6-methylguanine-DNA methyltransferase in thyrotropin-secreting pituitary adenomas

Objective Thyrotropin-secreting pituitary adenomas （TSHomas） account for about 2％ of all pituitary adenomas.Surgery is usually regarded as the conventional treatment for the pituitary adenomas,but the efficacy of surgery remains unsatisfactory.Some studies indicate that TMZ therapy correlated with the low expression of O-6-methylguanine-DNA methyltransferase.This study aims to investigate the immunohistochemical expression of MGMT in TSHomas and to analyze the potential application of TMZ as a therapeutic agent.Methods All pituitary adenomas patients （9 female,7 male,mean 53.2 ± 15.9） received pituitary surgery in the Department of Neurosurgery of Jinling Hospital.The expression of MGMT was detected by immunohistochemical SP method in 15 cases.Expression of positive nuclear was evaluated semi-quantitatively under the light microscopy.Results Among 15 cases half （53.3％） of TSH adenomas showed low MGMT immunoreactivity （＜25％） and 93.3％ of all tumors exhibited low MGMT immunoreactivity （≤50％）.Conclusion Temozolomide thus may be a new therapeutic option for TSHom as,particularly when conventional treatments are of little effect.