GSTs同工酶基因在乳腺癌中的扩增与基因的表达

采用ＤＮＡ和ＲＮＡ的斑点杂交分析方法，对３２例乳腺癌和相应的癌旁正常组织中ＧＳＴ－π、ＧＳＴ－α和ＧＳＴ－μ基因的ＤＮＡ扩增和ＲＮＡ转录表达情况进行研究，发现ＧＳＴ－π在乳腺癌中存在基因扩增和明显的ｍＲＮＡ表达升高，ＧＳＴ－π基因表达调控主要在转录水平进行的；ＧＳＴ－α和ＧＳＴ－μ在乳腺癌中表达水平较低，但仍可见α和μ类ＧＳＴ同工酶ｍＲＮＡ转录在肿瘤和正常组织中发生了较大的变化。结合乳腺癌中雌激素受体（ＥＲ）表达情况还发现ＧＳＴ－π表达水平与ＥＲ的表达存在负相关性。

The Amplification and Gene Expression of Glutathione S-Transferases in Human Breast Cancer

Incresased expression of the π-form of glutahione S-transferase(GST-π) has been reported in various tumor and preneoplastic tissue, including breast cancer. To further characterize the alteration of GSTs gene expression duing progression of breast cancer, both DNA and RNA levels of GST-π, α and β in 32 cases of breast cancer and their corresponding normal tissue were cxamined using biotin labelled GST cDNA probe and dot hybridization. The DNA hybridization resulted that the copies of GST-π gene has altered during the progressionof breast cancer. The copies of GST-π gene was revealed to be elevated in 14 out of 32 cases.These proved that GST-π gene has been amplified. An increased RNA expression was alsofound in 30% cases by RNA hybridization. These findings suggested that GST-π gene amplification or altered expression could serve as markers for breast cancer development. Low expressions of α and μ forms of GST were found in breast cancer, but there were differences in expression between tumorous and normal tissues. Moreover, an inverse correlation between GST-π and ER, PR status was revealed in breast cancer.