蛋白质的溴结构域和外端(BET)家族在各种癌症中显示出改变的表达。溴结构域(BRD)家族的成员包含与组蛋白和非组蛋白蛋白中的乙酰化赖氨酸残基结合的表观遗传阅读结构域。由于BRD蛋白参与癌症的发生和发展,这些蛋白质的治疗靶向最近是一个令人感兴趣的领域。在实验设置中,JQ1,一种常用的BRD抑制剂,是第一个已知的靶向含BRD蛋白4(BRD4)的抑制剂,广泛表达的BRD和外端家族蛋白。BRD4是正常细胞周期所必需的,它的异常表达激活了促炎细胞因子,导致肿瘤开始和进展。最近开发了各种BRD4抑制剂,并在临床前环境中进行了测试,目前正在进行临床试验。然而,和许多靶向治疗一样,BRD抑制剂治疗可导致对治疗的抗性。这里,我们调查了JQ1治疗中上调的激酶,这些激酶可能与BRD抑制剂一起作为联合治疗的靶标.为了识别激酶靶标,我们使用来自BRD抑制剂处理的细胞或BRD调节细胞的RNA对基因表达数据进行了比较分析,并确定了几种激酶的过表达,包括FYN,NEK9和ADCK5。我们进一步验证,通过免疫印迹,FYN酪氨酸激酶的过表达;NEK9丝氨酸/苏氨酸激酶和ADCK5,一种非典型激酶,证实其在BRD抑制剂治疗后的过表达。重要的是,我们的研究表明,靶向FYN或NEK9以及BRD抑制剂可有效降低癌细胞的增殖.因此,我们的研究强调了一种潜在的方法,即利用靶向一些过度表达的激酶的抑制剂与BRD抑制剂联合使用,以提高治疗效果.
The bromodomain and extraterminal (BET) family of proteins show altered expression across various cancers. The members of the bromodomain (BRD) family contain epigenetic reader domains that bind to acetylated lysine residues in both histone and non-histone proteins. Since BRD proteins are involved in cancer initiation and progression, therapeutic targeting of these proteins has recently been an area of interest. In experimental settings, JQ1, a commonly used BRD inhibitor, is the first known inhibitor to target BRD-containing protein 4 (BRD4), a ubiquitously expressed BRD and extraterminal family protein. BRD4 is necessary for a normal cell cycle, and its aberrant expression activates pro-inflammatory cytokines, leading to tumor initiation and progression. Various BRD4 inhibitors have been developed recently and tested in preclinical settings and are now in clinical trials. However, as with many targeted therapies, BRD inhibitor treatment can lead to resistance to treatment. Here, we investigated the
kinases up-regulated on JQ1 treatment that may serve as target for combination therapy along with BRD inhibitors. To identify kinase targets, we performed a comparative analysis of gene expression data using RNA from BRD inhibitor-treated cells or BRD-modulated cells and identified overexpression of several
kinases, including FYN, NEK9, and ADCK5. We further validated, by immunoblotting, the overexpression of FYN tyrosine kinase; NEK9 serine/threonine kinase and ADCK5, an atypical kinase, to confirm their overexpression after BRD inhibitor treatment. Importantly, our studies show that targeting FYN or NEK9 along with BRD inhibitor effectively reduces proliferation of cancer cells. Therefore, our research emphasizes a potential approach of utilizing inhibitors targeting some of the overexpressed
kinases in conjunction with BRD inhibitors to enhance therapeutic effectiveness.