• Biomolecules & Therapeutics
• /
• 제30권2호
• /
• pp.184-190
• /
• 2022

Targeting the cystine/glutamate exchange transporter, system x_c^-, is a promising anticancer strategy that induces ferroptosis, which is a distinct form of cell death mediated by iron-dependent lipid peroxidation. The concentration of ⳑ-cystine in culture medium is higher than the physiological level. This study was aimed to evaluate the effects of ⳑ-cystine concentration on the efficacy of ferroptosis inducers in hepatocellular carcinoma cells. This study showed that treatment with sulfasalazine or erastin, a system x_c^- inhibitor, decreased the viability of Huh6 and Huh7 cells in a dose-dependent manner, and the degree of growth inhibition was greater in medium containing a physiological ⳑ-cystine concentration of 83 µM than in commercial medium with a concentration of 200 µM ⳑ-cystine. However, RSL3, a glutathione peroxidase 4 inhibitor, decreased cell viability to a similar extent in media containing both ⳑ-cystine concentrations. Sulfasalazine and erastin significantly increased the percentages of propidium iodide-positive cells in media with 83 µM ⳑ-cystine, but not in media with 200 µM ⳑ-cystine. Sulfasalazine- or erastin-induced accumulation of lipid peroxidation as monitored by C11-BODIPY probe was higher in media with 83 µM ⳑ-cystine than in media with 200 µM ⳑ-cystine. In contrast, the changes in the percentages of propidium iodide-positive cells and lipid peroxidation by RSL3 were similar in both media. These results showed that sulfasalazine and erastin, but not RSL3, were efficacious under conditions of physiological ⳑ-cystine concentration, suggesting that medium conditions would be crucial for the design of a bioassay for system x_c^- inhibitors.

• Applied Microscopy
• /
• 제38권1호
• /
• pp.29-34
• /
• 2008

본 연구자는 Zinc Selenium autometallography ($ZnSe^{AMG}$) (Danscher et al., 1997) 염색법을 중심으로 중추신경계통 내 zinc ($Zn^{2+}$)의 분포와 이들을 함유하고 있는 신경종말, 소위 ZEN(zinc-enriched) terminals의 미세구조에 관하여 보고한 바 있다. 이번 연구에서는 다른 몇 가지, 즉 Neo-Timm staining (Danscher, 1982), TSQ fluorescence staining (Frederickson et al.,1987), Zinc transporter-3 Immunohistochemistry ($ZnT3^{IHC}$) (Palmiter et at., 1997) 염색법으로 흰쥐 해마복합체에 분포하는 $Zn^{2+}$를 염색한 후 이들의 염색패턴에서 차이점을 밝히고자 하였다. $ZnSe^{AMG}$ 염색법은 $Zn^{2+}$에 대한 특이성은 다소 떨어지나 광학 및 전자현미경하에서 관찰이 가능하며, 반영구적인 표본으로 보관이 가능하다는 장점이 있었고, TSQ는 $Zn^{2+}$에 대한 특이성이 매우 높을 뿐 아니라 그 염색법이 매우 간단하다는 장점이 있는 반면 형광물질의 안정성과 표본보관이 용이하지 않다는 단점이 있다. 그 외 Neo-Timm 염색법은 TSQ형광염색법과 유사한 염색 패턴을 보였으며, $ZnT3^{IHC}$염색법은 오히려 $ZnSe^{AMG}$에 가까운 염색의 결과를 보였다. 본 연구의 결과는 중추신경계통 내 $Zn^{2+}$에 관한 형태학적 연구에서 기초자료로 활용될 수 있을 것이다.