Shen Gang, Chen Jianchun, Zhou Yongqiang, Wang Zhenfan, Ma Zheng, Xu Chen, Jiang Minjun
Cell Physiol Biochem. 2018;50(2):798-809. doi: 10.1159/000494244. Epub 2018 Oct 11.
BACKGROUNDS/AIMS: Bromodomain-containing protein 4 (BRD4) overexpression participates in prostate cancer progression by enhancing the transcriptional activity and expression of several key oncogenes. AZD5153 is a novel BRD4 inhibitor.
Prostate cancer cells were treated with AZD5153. Cell survival was tested by MTT assay and clonogenicity assay. Cell proliferation was tested by [H3] DNA incorporation assay. Cell apoptosis was tested by caspase-3/-9 activity assay, Histone DNA ELISA assay, Annexin V FACS assay and TUNEL staining assay. Cell cycle progression was tested by propidium iodide (PI) FACS assay. Signaling was tested by Western blotting assay. The nude mice PC-3 xenograft model was applied to test AZD5153's activity in vivo.
AZD5153 inhibited proliferation and survival of established and primary prostate cancer cells. AZD5153 induced apoptosis activation and cell cycle arrest in prostate cancer cells. AZD5153 was non-cytotoxic to the prostate epithelial cells. AZD5153 downregulated BRD4 targets (cyclin D1, Myc, Bcl-2, FOSL1 and CDK4) in PC-3 and primary prostate cancer cells. Further studies show that AKT could be the primary resistance factor of AZD5153. Pharmacological inhibition or genetic depletion of AKT induced BRD4 downregulation, sensitizing AZD5153-induced cytotoxicity in PC-3 cells. In vivo, AZD5153 oral administration inhibited PC-3 xenograft tumor growth in nude mice. Its anti-tumor activity was further enhanced with co-treatment of the AKT specific inhibitor MK-2206.
Together, our results indicate a promising therapeutic value of the novel BRD4 inhibitor AZD5153 against prostate cancer cells.
背景/目的：含溴结构域蛋白4（BRD4）的过表达通过增强几种关键癌基因的转录活性和表达参与前列腺癌进展。AZD5153是一种新型BRD4抑制剂。
用AZD5153处理前列腺癌细胞。通过MTT法和克隆形成试验检测细胞存活率。通过[H3]DNA掺入试验检测细胞增殖。通过半胱天冬酶-3/-9活性试验、组蛋白DNA ELISA试验、膜联蛋白V流式细胞术试验和TUNEL染色试验检测细胞凋亡。通过碘化丙啶（PI）流式细胞术试验检测细胞周期进程。通过蛋白质免疫印迹试验检测信号传导。应用裸鼠PC-3异种移植模型在体内测试AZD5153的活性。
AZD5153抑制已建立的和原发性前列腺癌细胞的增殖和存活。AZD5153诱导前列腺癌细胞凋亡激活和细胞周期停滞。AZD5153对前列腺上皮细胞无细胞毒性。AZD5153下调PC-3和原发性前列腺癌细胞中BRD4的靶标（细胞周期蛋白D1、Myc、Bcl-2、FOSL1和CDK4）。进一步研究表明，AKT可能是AZD5153的主要耐药因子。对AKT进行药理抑制或基因敲除可诱导BRD4下调，使PC-3细胞对AZD5153诱导的细胞毒性敏感。在体内，口服AZD5153可抑制裸鼠中PC-3异种移植瘤的生长。与AKT特异性抑制剂MK-2206联合治疗可进一步增强其抗肿瘤活性。
总之，我们的结果表明新型BRD4抑制剂AZD5153对前列腺癌细胞具有有前景的治疗价值。
