Jin R, Bay B H, Chow V T, Tan P H
Department of Anatomy, Faculty of Medicine, National University of Singapore.
Breast Cancer Res Treat. 2001 Apr;66(3):265-72. doi: 10.1023/a:1010658907462.
Immunohistochemical expression of metallothioneins (MTs), a group of intracellular metal-binding proteins, is well documented in breast cancer. However, there is a paucity of information on the expression of the different MT isoforms in breast cancer tissues. The dichotomous association of MT overexpression with tumour types and progression led us to examine the role of the MT-1F mRNA isoform in breast cancer. We evaluated MT expression in 48 primary invasive ductal breast cancer tissues by immunohistochemistry, and the corresponding MT-1F mRNA expression via a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay. The specificity of the RT-PCR products was confirmed by direct cycle sequencing and restriction enzyme digestion. Immunohistochemical analysis of MT revealed a significantly higher MT expression in histological grade 3 tumours as compared to grade 1 and 2 tumours (p = 0.021). Similarly, MT-1F mRNA expression was found to be significantly higher in grade 3 tumours (p < 0.001). The results suggest that the MT-1F isoform influences histological differentiation in invasive ductal breast cancer. The converse is also true in that the histological grade may determine the level of MT-1F expression in breast cancer.
金属硫蛋白（MTs）是一类细胞内金属结合蛋白，其免疫组化表达在乳腺癌中已有充分记载。然而，关于乳腺癌组织中不同MT亚型表达的信息却很少。MT过表达与肿瘤类型及进展的二分关联促使我们研究MT-1F mRNA亚型在乳腺癌中的作用。我们通过免疫组化评估了48例原发性浸润性导管癌组织中的MT表达，并通过半定量逆转录-聚合酶链反应（RT-PCR）检测了相应的MT-1F mRNA表达。RT-PCR产物的特异性通过直接循环测序和限制性内切酶消化得以证实。MT的免疫组化分析显示，与1级和2级肿瘤相比，3级组织学肿瘤中的MT表达显著更高（p = 0.021）。同样，在3级肿瘤中发现MT-1F mRNA表达显著更高（p < 0.001）。结果表明，MT-1F亚型影响浸润性导管癌的组织学分化。反之亦然，即组织学分级可能决定乳腺癌中MT-1F的表达水平。
