Nath Niharika, Liu Xiaoping, Jacobs Lloydine, Kashfi Khosrow
Department of Physiology, Pharmacology, and Neuroscience, Sophie Davis School of Biomedical Education, City University of New York Medical School, New York, NY, USA.
Drug Des Devel Ther. 2013 May 6;7:389-96. doi: 10.2147/DDDT.S43771. Print 2013.
The Wnt/β-catenin/T cell factor (TCF) signaling pathway is important in the development of nonmelanoma skin cancers (NMSCs). Nitric-oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) are chemopreventive agents consisting of a traditional NSAID attached to an NO-releasing moiety through a chemical spacer. Previously we showed that an aromatic spacer enhanced the potency of a particular NO-NSAID compared to an aliphatic spacer.
We synthesized an NO-releasing NSAID with an aromatic spacer (flurbiprofen benzyl nitrate, NBS-242), and using the human skin cancer cell line A-431, we evaluated its effects on cell kinetics, Wnt/β-catenin, cyclin D1, and caspase-3.
NBS-242 inhibited the growth of A-431 cancer cells, being ~15-fold more potent than flurbiprofen and up to 5-fold more potent than NO-flurbiprofen with an aliphatic spacer, the half maximal inhibitory concentrations (IC50) for growth inhibition being 60 ± 4 μM, 320 ± 20 μM, and 880 ± 65 μM for NBS-242, NO-flurbiprofen, and flurbiprofen, respectively. This effect was associated with inhibition of proliferation, accumulation of cells in the G0/G1 phase of the cell cycle, and an increase in apoptotic cell population. NBS-242 cleaved β-catenin both in the cytoplasm and the nucleus of A-431 cells. NBS-242 activated caspase-3 whose activation was reflected in the cleavage of procaspase-3. To test the functional consequence of β-catenin cleavage, we determined the expression of cyclin D1, a Wnt-response gene. NBS-242 reduced cyclin D1 levels in a concentration dependent manner.
These findings establish a strong inhibitory effect of NBS-242 in A-431 human epidermoid carcinoma cells. NBS-242 modulates parameters that are important in determining cellular mass.
Wnt/β-连环蛋白/T细胞因子（TCF）信号通路在非黑色素瘤皮肤癌（NMSC）的发展中起重要作用。释放一氧化氮的非甾体抗炎药（NO-NSAIDs）是一种化学预防剂，由通过化学间隔基连接到释放NO部分的传统NSAID组成。先前我们表明，与脂肪族间隔基相比，芳香族间隔基增强了特定NO-NSAID的效力。
我们合成了一种带有芳香族间隔基的释放NO的NSAID（氟比洛芬苄酯硝酸盐，NBS-242），并使用人皮肤癌细胞系A-431，评估了其对细胞动力学、Wnt/β-连环蛋白、细胞周期蛋白D1和半胱天冬酶-3的影响。
NBS-242抑制A-431癌细胞的生长，其效力比氟比洛芬高约15倍，比带有脂肪族间隔基的NO-氟比洛芬高5倍，生长抑制的半数最大抑制浓度（IC50）分别为：NBS-242为60±4μM，NO-氟比洛芬为320±20μM，氟比洛芬为880±65μM。这种作用与增殖抑制、细胞在细胞周期G0/G1期的积累以及凋亡细胞群体的增加有关。NBS-242在A-431细胞的细胞质和细胞核中均切割β-连环蛋白。NBS-242激活半胱天冬酶-3，其激活反映在原半胱天冬酶-3的切割上。为了测试β-连环蛋白切割的功能后果，我们测定了Wnt反应基因细胞周期蛋白D1的表达。NBS-242以浓度依赖性方式降低细胞周期蛋白D1水平。
这些发现证实了NBS-242对A-431人表皮样癌细胞具有强大的抑制作用。NBS-242调节在决定细胞质量方面很重要的参数。
