Nesbitt Heather, Browne Gillian, O'Donovan Katie M, Byrne Niall M, Worthington Jenny, McKeown Stephanie R, McKenna Declan J
Biomedical Science Research Institute, University of Ulster, Coleraine, Londonderry, Northern Ireland.
Department of Biochemistry and Vermont Cancer Center, University of Vermont College of Medicine, Burlington, Vermont.
J Cell Physiol. 2016 Feb;231(2):473-82. doi: 10.1002/jcp.25093.
Aberrant expression of the transcription factor RUNX2 in prostate cancer has a number of important consequences including increased resistance to apoptosis, invasion and metastasis to bone. We previously demonstrated that hypoxia up-regulated RUNX2 in tumour cells, which in turn up-regulated the anti-apoptotic factor Bcl-2. Here, we investigate the impact of nitric oxide (NO) on RUNX2 and Bcl-2 expression in prostate cancer and further, how RUNX2 over-expression can impact tumour growth, angiogenesis and oxygenation in vivo. The effect of NO levels on RUNX2 and thus Bcl-2 expression was examined in prostate cancer cells in vitro using methods including gene and protein expression analyses, nitrite quantitation, protein-DNA interaction assays (ChIP) and viability assays (XTT). The effect of RUNX2 over-expression on tumour physiology (growth, oxygenation and angiogenesis) was also assessed in vivo using LNCaP xenografts. A low (but not high) concentration of NO (10 μM) induced expression of RUNX2 and Bcl-2, conferring resistance to docetaxel. These effects were induced via the ERK and PI3K pathways and were dependent on intact AP-1 binding sites in the RUNX2 promoter. RUNX2 over-expression in LNCaP tumours in vivo decreased the time to tumour presentation and increased tumour growth. Moreover, these tumours exhibited improved tumour angiogenesis and oxygenation. Low levels of NO increase expression of RUNX2 and Bcl-2 in LNCaP prostate tumour cells, and in vivo up-regulation of RUNX2 created tumours with a more malignant phenotype. Collectively, our data reveals the importance of NO-regulation of key factors in prostate cancer disease progression.
转录因子RUNX2在前列腺癌中的异常表达会产生许多重要后果，包括对细胞凋亡的抗性增加、侵袭以及向骨转移。我们之前证明，缺氧会上调肿瘤细胞中的RUNX2，这反过来又会上调抗凋亡因子Bcl-2。在此，我们研究一氧化氮（NO）对前列腺癌中RUNX2和Bcl-2表达的影响，以及RUNX2过表达如何在体内影响肿瘤生长、血管生成和氧合。使用基因和蛋白质表达分析、亚硝酸盐定量、蛋白质-DNA相互作用分析（ChIP）和活力分析（XTT）等方法，在体外前列腺癌细胞中检测了NO水平对RUNX2以及Bcl-2表达的影响。还使用LNCaP异种移植模型在体内评估了RUNX2过表达对肿瘤生理学（生长、氧合和血管生成）的影响。低浓度（而非高浓度）的NO（10 μM）诱导RUNX2和Bcl-2的表达，赋予对多西他赛的抗性。这些效应是通过ERK和PI3K途径诱导的，并且依赖于RUNX2启动子中完整的AP-1结合位点。体内LNCaP肿瘤中RUNX2过表达缩短了肿瘤出现的时间并增加了肿瘤生长。此外，这些肿瘤表现出改善的肿瘤血管生成和氧合。低水平的NO增加了LNCaP前列腺肿瘤细胞中RUNX2和Bcl-2的表达，并且体内RUNX2的上调产生了具有更恶性表型特征的肿瘤。总的来说，我们的数据揭示了NO调节关键因子在前列腺癌疾病进展中的重要性。
