Microbes have long been used for the synthesis of a variety of nanoparticles. Hepatocellular carcinoma (HCC) is the primary liver cancer and it is the second leading cause of cancer‐related mortality worldwide. In this study, we have synthesized Enterococcus mediated gold nanoparticles (AuNPs) and investigated their cytotoxic potential against human hepatocellular cancer cell line (HepG2). AuNPs were synthesized using Enterococcus sp. RMAA. HepG2 cells were treated with different concentrations of AuNPs for 24 hours and cytotoxicity was analyzed by MTT ((4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay. AuNPs induced reactive oxygen species expression was analyzed by 2′,7′‐dichlorodihydrofluorescein diacetate staining. Morphological changes related to apoptosis was analyzed by annexin V/propidium iodide staining. Protein expression of proliferating cell nuclear antigen (PCNA) was done by western blotting analysis. Bacterial‐mediated AuNPs caused significant cytotoxicity in HepG2 cells. AuNPs treatment also caused the significant expression of ROS and morphological damage related to apoptosis. AuNPs treatments were responsible for the dislocation of cytochrome c from mitochondria to cytosol. The protein expression of PCNA was significantly decreased upon AuNPs treatment. These findings suggest that Enterococcus‐mediated AuNPs can inhibit the proliferation of HepG2 cells via intracellular ROS mediated apoptosis, decreased PCNA expressions, and it may have the potential to treat HCC.

中文翻译：

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环保合成的金纳米颗粒通过 HepG2 细胞凋亡诱导细胞毒性

微生物长期以来被用于合成各种纳米颗粒。肝细胞癌（HCC）是原发性肝癌，是全球癌症相关死亡的第二大原因。在这项研究中，我们合成了肠球菌介导的金纳米颗粒（AuNP），并研究了它们对人肝细胞癌细胞系（HepG2）的细胞毒性潜力。AuNPs 使用肠球菌 sp. 合成。RMAA。HepG2细胞用不同浓度的AuNP处理24小时，并通过MTT（（4,5-二甲基噻唑-2-基）-2,5-二苯基溴化四唑）测定分析细胞毒性。通过 2',7'-二氯二氢荧光素二乙酸盐染色分析 AuNPs 诱导的活性氧表达。通过膜联蛋白V/碘化丙啶染色分析与细胞凋亡相关的形态学变化。通过蛋白质印迹分析进行增殖细胞核抗原（PCNA）的蛋白质表达。细菌介导的 AuNPs 在 HepG2 细胞中引起显着的细胞毒性。AuNPs 处理还引起 ROS 的显着表达和与细胞凋亡相关的形态损伤。AuNPs 处理导致细胞色素 c 从线粒体错位到细胞质。AuNPs 处理后 PCNA 蛋白表达显着降低。这些发现表明，肠球菌介导的AuNPs可以通过细胞内ROS介导的细胞凋亡、降低PCNA表达来抑制HepG2细胞的增殖，并且可能具有治疗HCC的潜力。