Wade Mark A, Jones Dominic, Wilson Laura, Stockley Jacqueline, Coffey Kelly, Robson Craig N, Gaughan Luke
Northen Institute for Cancer Research, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
Nucleic Acids Res. 2015 Jan;43(1):196-207. doi: 10.1093/nar/gku1298. Epub 2014 Dec 8.
Endocrine therapy has successfully been used to treat estrogen receptor (ER)-positive breast cancer, but this invariably fails with cancers becoming refractory to treatment. Emerging evidence has suggested that fluctuations in ER co-regulatory protein expression may facilitate resistance to therapy and be involved in breast cancer progression. To date, a small number of enzymes that control methylation status of histones have been identified as co-regulators of ER signalling. We have identified the histone H3 lysine 9 mono- and di-methyl demethylase enzyme KDM3A as a positive regulator of ER activity. Here, we demonstrate that depletion of KDM3A by RNAi abrogates the recruitment of the ER to cis-regulatory elements within target gene promoters, thereby inhibiting estrogen-induced gene expression changes. Global gene expression analysis of KDM3A-depleted cells identified gene clusters associated with cell growth. Consistent with this, we show that knockdown of KDM3A reduces ER-positive cell proliferation and demonstrate that KDM3A is required for growth in a model of endocrine therapy-resistant disease. Crucially, we show that KDM3A catalytic activity is required for both ER-target gene expression and cell growth, demonstrating that developing compounds which target demethylase enzymatic activity may be efficacious in treating both ER-positive and endocrine therapy-resistant disease.
内分泌疗法已成功用于治疗雌激素受体（ER）阳性乳腺癌，但这种疗法最终总会失效，因为癌症会对治疗产生耐药性。新出现的证据表明，ER共调节蛋白表达的波动可能会促进对治疗的耐药性，并参与乳腺癌的进展。迄今为止，少数控制组蛋白甲基化状态的酶已被确定为ER信号传导的共调节因子。我们已确定组蛋白H3赖氨酸9单甲基化和二甲基化去甲基化酶KDM3A是ER活性的正向调节因子。在此，我们证明通过RNA干扰使KDM3A缺失可消除ER与靶基因启动子内顺式调节元件的结合，从而抑制雌激素诱导的基因表达变化。对KDM3A缺失细胞的全基因组表达分析确定了与细胞生长相关的基因簇。与此一致的是，我们发现敲低KDM3A可减少ER阳性细胞的增殖，并证明在抗内分泌治疗疾病模型中生长需要KDM3A。至关重要的是，我们表明ER靶基因表达和细胞生长都需要KDM3A的催化活性，这表明开发靶向去甲基酶活性的化合物可能对治疗ER阳性和抗内分泌治疗疾病均有效。
