Protein Arginine Methylation in Breast Cancer

项目总结/摘要 在癌症中鉴定的所有驱动基因中，约有30%与染色质结构和功能相关。 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 癌症的染色质调节因子依赖性机制的鉴定的翻译后修饰 进展和转移。BAF 155是SWI/SNF染色质重塑复合物的一个组分， 由精氨酸甲基转移酶CARM 1在单个位点R1064甲基化。使用甲基-BAF 155（Me- 对于ChIP-seq的me-BAF 155）特异性抗体，我们发现me-BAF 155结合峰富含高浓度的 密度H3 K27 Ac和H3 K4 me 1，其特征在于超级增强子（SE）。SE是重要的监管机构 癌细胞中控制癌基因表达的元件。因为SE招募含有布罗莫结构域的 在BRD 4蛋白的表达中，癌基因的表达水平通常对BRD 4抑制剂JQ 1敏感。我们 结果表明，JQ 1和CARM 1抑制剂处理均阻断了me-BAF 155靶基因的表达 以及me-BAF 155和BRD 4向乳腺癌细胞中候选基因的募集。这导致 假设me-BAF 155调节对SE成瘾的癌基因，从而促进癌症转移。要求1 将检查用JQ 1和CARM 1抑制剂治疗后的整体me-BAF 155染色质缔合。 由于JQ 1正在进行治疗各种癌症类型的临床研究，因此， 在me-BAF 155驱动的癌症中通过SE进行的基因调控将提出治疗乳腺癌的新治疗方法。 具有高水平me-BAF 155的癌症。我们将用不同的细胞系和病人来检验我们的假设- 衍生的异种移植模型。此外，微阵列和me-BAF 155 ChIP-seq数据的整合鉴定了 Hippo通路中依赖于BAF 155甲基化的关键基因。因此，我们的第二个假设 正在测试的（目的2）是由me-BAF 155增强的雅普活性有助于细胞生长、侵袭和 转移总的来说，我们的研究将验证me-BAF 155在驱动癌症中的功能意义。 在不同的临床前模型转移，并提供了致癌功能的机制见解， me-BAF 155.表观遗传疗法尚未广泛用于乳腺癌治疗，这是由于缺乏 明确的靶点和表观遗传酶的特异性抑制剂。我们的学习将为未来的 靶向BAF 155甲基化反应的表观遗传药物（例如CARM 1抑制剂）在预防 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.