Imidazole ketone erastin  别名：Ferroptosis inducer IKE; PUN-30119

Imidazole ketone erastin (IKE) 是一个ferroptosis铁死亡的诱导剂，它也是一种有效的，选择性的，代谢稳定的system xc–抑制剂。在弥漫性大 B 细胞淋巴瘤 (DLBCL) 异种移植模型中，IKE 通过抑制系统 xc- 发挥抗肿瘤作用，导致谷胱甘肽耗竭、脂质过氧化和铁死亡生物标志物的诱导。

Mouse model of inflammatory arthritis

Male DBA/1 mice aged 8–10 weeks were maintained in a specific pathogen-free (SPF) mouse facility (room temperature, 20–22 °C; room humidity, 40–60%) with free access to food and water under a 12 h light/dark cycle. Experimental and control mice were co-housed in individual cages (maximum n = 5 per cage) during the experiment ensuring identical environmental conditions. CIA was established by injecting DBA/1 mice with chicken type II collagen emulsified in complete Freund’s adjuvant (CFA), followed by boosting 21 days later with type II collagen emulsified in incomplete Freund’s adjuvant (IFA) (Chondrex). The development of arthritis was monitored and the arthritis score was evaluated every 2 days. The level of inflammation for each paw was graded from 0 to 4 by the following scale: 0 = absence of inflammation, 1 = paw with detectable swelling in a single digit, 2 = paw with swelling in more than one digit, 3 = paw with swelling of all digits and instep, and 4 = severe swelling of the paw and ankle. The arthritic scores of four paws were summed. For CIA model, vehicle, IKE, liproxstatin-1, and/or etanercept were introduced into CIA mice via peritoneal injection at the moment of inflammation onset (defined as day 0). Vehicle for IKE and liproxstatin-1: 5% DMSO, 40% PEG300, 5% Tween80, 50% ddH2O. DBA/1 mice were monitored every 2 days for signs of arthritis based on paw swelling and arthritis scores. At the end of the study, blood samples were collected from mice under deep anesthesia, and then all the mice were euthanized by an intraperitoneal injection of pentobarbital.

In-vivo tumor models

For cell line-derived xenograft (CDX) assays, 6-week-old male BALB/c-nude mice were randomly assigned into groups (5 mice per group) to receive respective treatments. To observer the in vivo effect of ERO1α and SLC7A11, 4 × 10⁶ corresponding cell lines in 0.2 ml PBS were subcutaneously inoculated into the axilla of mice to establish tumor models. On day 9 after inoculation with shERO1α1 LIU-LSC-1 cells, the mice were treated with Lip-1 (10 mg/kg, once every other day, a total of 10 injections) to assess the impact of ferroptosis inhibition on the tumoral growth of ERO1α-knockdown cells. To evaluate the therapeutic efficacy of IKE in CDX models, the mice were treated with IKE (30 mg/kg, once every other day) or vehicle for a total of 10 injections on day 17 after inoculation with sgERO1α NTC/T1 null cells and the control cells.

The LSCC PDX models were established following protocols as described previously. When the passage 3 xenografts reached a mean volume of 100 mm3, the mice were randomly divided into 4 groups (n = 5 per group), and treated with ERO1α siRNA (100 μg, three times per week) or siNC, together with IKE (40 mg/kg, once every other day) or vehicle.

Lip-1 and IKE were dissolved in vehicle (10% DMSO, 40% PEG300, 5% Tween 80, and 45% saline) and intraperitoneal injection. The chemically modified ERO1α siRNAs were intratumorally injected. Tumor size was measured every 3 days with a digital caliper, and volume was calculated using the standard formula: volume (mm³) = 0.5 × (length × width²). Body weights were also monitored. At the endpoint indicated in the corresponding figures, animals were sacrificed, and the subcutaneous tumor masses were taken out for subsequent studies.