O6-methylguanine-DNA methyltransferase activity in human tumors.
O6-methylguanine-DNA methyltransferase activity in human tumors.
复制标题
人类肿瘤中的 O6-甲基鸟嘌呤-DNA 甲基转移酶活性。
作者：
Jian;Yang;Cai Wang;Yan Sun;J. Fujimoto;Mituo Ikenaga
测量了 74 名患者肿瘤提取物中 O6-甲基鸟嘌呤-DNA 甲基转移酶 (MGMT) 活性的分布。结果表明，不同人类肿瘤组织以及不同个体的MGMT活性存在相当大的差异。乳腺癌、胃癌、小细胞肺癌、非小细胞肺癌、肾细胞癌、食道癌、脑肿瘤、结肠癌和恶性黑色素瘤的平均值（X +/- SD，pmol/mg 蛋白质）分别为 1.071 +/- 0.374 (9)、0.515 +/- 0.107 (5)、0.509 +/- 0.251 (5)、0.461+/-0.227(24)、0.329+/-0.246(5)、0.273+/-0.376(5)、0.244+/-0.175(14)、0.242+/-0.308(5)和0.201+/-0.161(2)。值得注意的是，6 个样本（1/24 非小细胞肺癌、3/5 食管癌、1/14 脑肿瘤和 1/5 结肠癌）没有任何可检测到的 MGMT 活性水平。还在用于测定 MGMT 活性的相同提取物中测量了谷氨酰胺丙酮转氨酶 (GPT) 的活性。这些具有不可检测的 MGMT 活性水平的样品中的 GPT 活性与具有显着 MGMT 活性的样品相似。这些结果进一步强化了人类肿瘤的某一部分是 Mer- 的假设。
The distribution of O6-methylguanine-DNA methyltransferase (MGMT) activity in extracts of tumors from 74 patients was measured. The results demonstrated that there was considerable variation of MGMT activity in different human tumor tissues as well as in different individuals. The mean values (X +/- SD, pmol/mg of protein) in breast cancer, stomach cancer, small cell lung cancer, non-small cell lung cancer, renal cell carcinoma, esophageal carcinoma, brain tumors, colon carcinoma and malignant melanoma were 1.071 +/- 0.374 (9), 0.515 +/- 0.107 (5), 0.509 +/- 0.251 (5), 0.461 +/- 0.227 (24), 0.329 +/- 0.246 (5), 0.273 +/- 0.376 (5), 0.244 +/- 0.175 (14), 0.242 +/- 0.308 (5) and 0.201 +/- 0.161 (2) respectively. It was notable that six samples (1/24 non-small cell lung cancer, 3/5 esophageal carcinoma, 1/14 brain tumors and 1/5 colon carcinoma) did not have any detectable level of MGMT activity. Activity of glutamine pyruvic transaminase (GPT) was also measured in the same extracts used for the assay of MGMT activity. The activity of GPT in these samples with undetectable level of MGMT activity was similar to those with significant MGMT activity. These results further strengthen the assumption that a certain fraction of human tumors are Mer-.