Department of Medical Biotechnology, School of Medicine, Flinders University, Adelaide, SA, 5001, Australia.
Toxicol Mech Methods. 2007;17(4):223-32. doi: 10.1080/15376510600943775.
ABSTRACT Respirable quartz is a potential human lung carcinogen. The mechanisms involved in this carcinogenesis, however, remain unclear, especially for the ultrafine particles (diameter <100 nm). The aim of the present study was to investigate the effects caused by ultrafine quartz (UF-quartz) in a human cell culture model. Genotoxicity and cytotoxicity induced by UF-quartz were investigated through the cytokinesis block micronucleus assay (CBMN), the Comet assay, the HPRT assay, the population growth assay, and the 3-(4, 5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. WIL2-NS cells were incubated for 10h with 0, 60, and 120 mug/mL UF-quartz. Significant decreases in percent of cell survival in the MTT assay were seen at higher doses, for example, 83%, and 64% relative survival at 60 mug/mL and 120 mug/mL, respectively. Only slight population regrowth was observed, with the population sizes recovering slightly by day 4 after quartz particles were removed. A significant increase in the frequency of micronucleated binucleated cells (MNed BNCs) was seen with 120 mug/mL quartz, from approximately 5 in 1000 BNCs in controls to 12 in 1000 BNCs. A significant reduction in the nuclear division index was observed by the CBMN assay, indicating inhibition of cell division by high-dose UF-quartz. A dose-dependent increase in induced HPRT-gene locus mutant frequency with increasing dose of UF-quartz was observed by the HPRT assay. No significant difference was found in DNA strand breakage as detected by the Comet assay. Collective findings suggest that UF-quartz can cause cytotoxicity and genotoxicity to human lymphoblasts in this model system.
摘要 可吸入石英是一种潜在的人类肺部致癌物。然而，这种致癌作用的机制仍不清楚，尤其是对于超细颗粒（直径 <100nm）。本研究的目的是在人细胞培养模型中研究超细石英（UF-石英）引起的影响。通过细胞有丝分裂阻断微核试验（CBMN）、彗星试验、HPRT 试验、群体生长试验和 3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐（MTT）试验研究 UF-石英引起的遗传毒性和细胞毒性。将 WIL2-NS 细胞与 0、60 和 120μg/mLUF-石英孵育 10h。MTT 试验中，较高剂量（例如 60μg/mL 和 120μg/mL 时的 83%和 64%相对存活率）可见细胞存活率百分比显著下降。观察到轻微的群体再生，在去除石英颗粒后第 4 天，群体大小略有恢复。彗星试验显示，120μg/mL 石英组双核微核细胞（MNedBNC）的频率显著增加，从对照中每 1000 个 BNC 中的约 5 个增加到每 1000 个 BNC 中的 12 个。CBMN 试验观察到核分裂指数显著降低，表明高剂量 UF-石英抑制细胞分裂。HPRT 试验观察到随着 UF-石英剂量的增加，诱导的 HPRT 基因座突变频率呈剂量依赖性增加。彗星试验未发现 DNA 链断裂有显著差异。研究结果表明，在该模型系统中 UF-石英可引起人淋巴母细胞的细胞毒性和遗传毒性。
