Abstract:
Citrinin (CIT), a polyketide mycotoxin produced by Penicillium, Aspergillus, and Monascus species, is a contaminant that has been found in various food commodities and was also detected in house dust. Several studies showed that CIT can impair the kidney, liver, heart, immune, and reproductive systems in animals by mechanisms so far not completely elucidated. In this study, we investigated the CIT mode of action on two human tumor cell lines, HepG2 (hepatocellular carcinoma) and A549 (lung adenocarcinoma). Cytotoxic concentrations were determined using an MTT proliferation assay. The genotoxic effect of sub-IC50 concentrations was investigated using the alkaline comet assay and the impact on the cell cycle using flow cytometry. Additionally, the CIT effect on the total amount and phosphorylation of two cell-cycle-checkpoint proteins, the serine/threonine kinase Chk2 and Fanconi anemia (FA) group D2 (FANCD2), was determined by the cell-based ELISA. The data were analyzed using GraphPad Prism statistical software. The CIT IC50 for HepG2 was 107.3 µM, and for A549, it was >250 µM. The results showed that sensitivity to CIT is cell-type dependent and that CIT in sub-IC50 and near IC50 induces significant DNA damage and cell-cycle arrest in the G2/M phase, which is related to the increase in total and phosphorylated Chk2 and FANCD2 checkpoint proteins in HepG2 and A549 cells.
摘要:
柑橘素(CIT),一种由青霉菌产生的聚酮霉菌毒素,曲霉菌,和红曲霉物种,是一种在各种食品中发现的污染物,也在房屋灰尘中检测到。几项研究表明CIT可以损害肾脏,肝脏,心,免疫,和动物生殖系统的机制到目前为止还没有完全阐明。在这项研究中,我们研究了CIT对两种人类肿瘤细胞系的作用模式,HepG2(肝细胞癌)和A549(肺腺癌)。使用MTT增殖测定法测定细胞毒性浓度。使用碱性彗星测定法研究亚IC50浓度的遗传毒性作用,并使用流式细胞术研究对细胞周期的影响。此外,CIT对两种细胞周期检查点蛋白的总量和磷酸化的影响,丝氨酸/苏氨酸激酶Chk2和范可尼贫血(FA)组D2(FANCD2),通过基于细胞的ELISA测定。使用GraphPadPrism统计软件分析数据。HepG2的CITIC50为107.3µM,对于A549,它>250µM。结果表明,对CIT的敏感性是细胞类型依赖性的,在亚IC50和接近IC50的CIT在G2/M期诱导显著的DNA损伤和细胞周期停滞,这与HepG2和A549细胞中总的和磷酸化的Chk2和FANCD2检查点蛋白的增加有关。