Nandhini Joseph T, Ezhilarasan Devaraj, Rajeshkumar Shanmugam
Department of Pharmacology, Saveetha Dental College, Chennai, India.
Biomedical Research Unit and Laboratory Animal Centre, Saveetha Dental College (SDC), Chennai, India.
Environ Toxicol. 2021 Jan;36(1):24-32. doi: 10.1002/tox.23007. Epub 2020 Aug 14.
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.
长期以来，微生物一直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主要原因。在本研究中，我们合成了肠球菌介导的金纳米颗粒（AuNPs），并研究了它们对人肝癌细胞系（HepG2）的细胞毒性潜力。使用肠球菌属RMAA合成AuNPs。用不同浓度的AuNPs处理HepG2细胞24小时，并通过MTT（（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐）试验分析细胞毒性。通过2',7'-二氯二氢荧光素二乙酸酯染色分析AuNPs诱导的活性氧物种表达。通过膜联蛋白V/碘化丙啶染色分析与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细胞中引起显著的细胞毒性。AuNPs处理还导致ROS的显著表达和与凋亡相关的形态学损伤。AuNPs处理导致细胞色素c从线粒体移位到细胞质。AuNPs处理后PCNA的蛋白质表达显著降低。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。
