Protein Arginine Methylation in Breast Cancer

项目摘要/摘要 在癌症中发现的所有驱动基因中，约有30%与染色质结构和功能有关。 与涉及表观遗传修饰物表达改变或突变的常见机制不同，我们 肿瘤中染色质调节因子依赖机制的翻译后修饰 进展和转移。BAF155是SWI/SNF染色质重塑复合体的一种成分，是 由精氨酸甲基转移酶CARM1在单个位点R1064甲基化。使用甲基-BAF155(Me- BAF155)特异的芯片序列抗体，我们发现Me-BAF155的结合峰高度富集. 密度H3K27Ac和H3K4me1，具有超级增强剂(SE)。SE是重要的监管机构 癌细胞中癌基因表达的控制因素。因为SE招募的溴域含有 蛋白BRD4，癌基因的表达水平往往对BRD4抑制剂JQ1敏感。我们 结果表明，JQ1和CARM1抑制剂处理均阻断了Me-BAF155靶基因的表达 以及Me-BAF155和BRD4在乳腺癌细胞中招募到候选基因。这导致了 假设Me-BAF155调节上瘾于SES的癌基因，从而促进癌症转移。目标1 将在使用JQ1和CARM1抑制剂治疗时检查全球Me-BAF155染色质的相关性。 由于JQ1正在进行临床研究，用于治疗各种类型的癌症，因此JQ1的新机制 在Me-BAF155驱动的癌症中通过SES进行基因调控将为乳腺癌的治疗提供新的治疗手段 Me-BAF155高水平的癌症。我们将使用不同的细胞系和患者来验证我们的假设- 衍生异种移植模型。此外，微阵列和Me-BAF155芯片序列数据的集成识别 河马途径中的关键基因依赖于BAF155甲基化。因此，我们的第二个假设 正在测试(目标2)的是Me-BAF155增强的YAP活性有助于细胞生长、侵袭和 转移。总而言之，我们的研究将验证Me-BAF155在推动癌症方面的功能意义 在不同的临床前模型中的转移，并提供对致癌功能的机制洞察 ME-BAF155。表观遗传疗法尚未被广泛应用于乳腺癌的治疗，因为缺乏 确定了表观遗传酶的靶标和特定的抑制物。我们的研究将为以下工作奠定坚实的基础 针对BAF155甲基化反应的表观遗传药物(如CARM1抑制剂)在预防中的应用 以及治疗乳腺癌转移。

PROJECT SUMMARY/ABSTRACT Approximately 30% of all driver genes identified in cancer are related to chromatin structure and function. Distinct from common mechanisms involving altered expression or mutations of epigenetic modifiers, we identified post-translational modification of a chromatin regulator dependent mechanism for cancer progression and metastasis. BAF155, a component of SWI/SNF chromatin remodeling complex, is methylated by arginine methyltransferase CARM1 at a single site, R1064. Using methyl-BAF155 (me- BAF155) specific antibody for ChIP-seq, we found that me-BAF155 binding peaks are enriched with high- density H3K27Ac and H3K4me1 that feature the super-enhancers (SEs). SEs are important regulatory elements controlling oncogene expression in cancer cells. Because SEs recruit bromodomain containing protein BRD4, the expression levels of oncogenes are often sensitive to the BRD4 inhibitor JQ1. We showed that both JQ1 and CARM1 inhibitor treatment blocked the expression of me-BAF155 target genes and the recruitment of me-BAF155 and BRD4 to candidate genes in breast cancer cells. This leads to the hypothesis that me-BAF155 regulates oncogenes addicted to SEs thus promoting cancer metastasis. Aim 1 will examine the global me-BAF155 chromatin association upon treatment with JQ1 and CARM1 inhibitors. Because JQ1 is under clinical investigation for treatment of various cancer types, the novel mechanism of gene regulation via SEs in me-BAF155 driven cancer would suggest new therapeutic means to treat breast cancers with high levels of me-BAF155. We will test our hypothesis using different cell lines and patient- derived xenograft models. Furthermore, integration of microarray and me-BAF155 ChIP-seq data identifies key genes in the Hippo pathway dependent on BAF155 methylation. Therefore, our second hypothesis being tested (Aim 2) is that YAP activity potentiated by me-BAF155 contributes to cell growth, invasion and metastasis. Collectively, our study will validate the functional significance of me-BAF155 in driving cancer metastasis in different pre-clinical models and provide mechanistic insights into the oncogenic functions of me-BAF155. Epigenetic therapy has not been widely used for breast cancer treatment due to the lack of defined target and specific inhibitors for epigenetic enzymes. Our studies will lay solid foundation for the application of epigenetic drugs (e.g. CARM1 inhibitor) that target BAF155 methylation reaction in preventing and treating breast cancer metastasis.