Zinc oxide nanoparticles (ZnO-NPs) are used immensely in technology and medicine, but very less is known about toxicity mechanism to human epidermal cells. The objective of this study was to evaluate possible anticancer properties of ZnO-NPs on human epidermoid carcinoma cells using MTT assay, measurement of reactive oxygen species, DNA fragmentation, and nuclear condensation. ZnO-NPs were synthesized by sol-gel method using zinc acetate dihydrate, ethylene glycol, and 2-propyl alcohol. Numerous characterization techniques such as UV-visible spectroscopy, X-ray powder diffraction, transmission electron microscopy, and dynamic light scattering spectroscopy were used to confirm synthesis, purity, optical, and surface characteristics, size, shape, and distribution of ZnO-NPs. Our finding showed that ZnO-NPs considerably decreased cell viability of human epidermoid carcinoma A431 cells with a parallel increase in nuclear condensation and DNA fragmentation in a dose dependent manner. Moreover, real time PCR expression study showed that treatment of human epidermoid carcinoma cells with ZnO-NPs trigger increased expression of tumor suppressor gene p53, bax, and caspase-3 while downregulate antiapoptotic gene bcl-2. Thus ZnO-NPs induce apoptosis in A431 cells through DNA degradation and generation of reactive oxygen species via p53, bax/bcl-2, and caspase pathways.

中文翻译：

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氧化锌纳米颗粒通过活性氧和 DNA 降解诱导人表皮样癌细胞凋亡。

氧化锌纳米粒子 (ZnO-NPs) 在技术和医学中得到了广泛的应用，但对人类表皮细胞的毒性机制知之甚少。本研究的目的是使用 MTT 测定、活性氧的测量、DNA 断裂和核凝聚来评估 ZnO-NPs 对人表皮样癌细胞的可能抗癌特性。ZnO-NPs 是通过溶胶-凝胶法使用醋酸锌二水合物、乙二醇和 2-丙醇合成的。多种表征技术，如紫外-可见光谱、X 射线粉末衍射、透射电子显微镜和动态光散射光谱，用于确认 ZnO-NPs 的合成、纯度、光学和表面特征、尺寸、形状和分布。我们的发现表明，ZnO-NPs 显着降低了人表皮样癌 A431 细胞的细胞活力，并以剂量​​依赖性方式平行增加核浓缩和 DNA 断裂。此外，实时 PCR 表达研究表明，用 ZnO-NPs 处理人表皮样癌细胞会引发肿瘤抑制基因 p53、bax 和 caspase-3 的表达增加，同时下调抗凋亡基因 bcl-2。因此，ZnO-NPs 通过 DNA 降解和通过 p53、bax/bcl-2 和 caspase 途径产生活性氧来诱导 A431 细胞凋亡。实时 PCR 表达研究表明，用 ZnO-NPs 处理人表皮样癌细胞会引发肿瘤抑制基因 p53、bax 和 caspase-3 的表达增加，同时下调抗凋亡基因 bcl-2。因此，ZnO-NPs 通过 DNA 降解和通过 p53、bax/bcl-2 和 caspase 途径产生活性氧来诱导 A431 细胞凋亡。实时 PCR 表达研究表明，用 ZnO-NPs 处理人表皮样癌细胞引发肿瘤抑制基因 p53、bax 和 caspase-3 的表达增加，同时下调抗凋亡基因 bcl-2。因此，ZnO-NPs 通过 DNA 降解和通过 p53、bax/bcl-2 和 caspase 途径产生活性氧来诱导 A431 细胞凋亡。