Department of Hematology, Yixing People's Hospital, Yixing City, Jiangsu Province, China.
Immun Inflamm Dis. 2021 Sep;9(3):827-839. doi: 10.1002/iid3.437. Epub 2021 May 6.
Acute lymphoblastic leukemia (ALL) is a usual hematological tumor, which was featured by malignant proliferation of lymphoid progenitor cells. Many important factors participate into the regulation of ALL, including proteins. PAQR3 (also named RKTG) has been proved to take part in many human cancers by acting as a tumor suppressor. PAQR3 has bee n shown to repress human leukemia cells proliferation and induce cell apoptosis, but its role and relevant regulatory mechanism on cell proliferation and ferroptosis in ALL needs more exploration.
The genes expression was detected through quantitative reverse transcription polymerase chain reaction (mRNA) or western blot (protein). The cell proliferation was assessed through Cell Counting Kit-8 and 5-ethynyl-2-deoxyuridine assays. The levels of MDA, DCF, and intracellular free Fe in ALL cells were tested through the commercial kits. The cell apoptosis was determined through flow cytometry analysis. The binding ability of PAQR3 and nuclear factor erythroid 2-related factor 2 (Nrf2) was verified through pull down assay.
PAQR3 expression was firstly assessed in ALL patients and cell lines, and discovered to be downregulated. It was verified that PAQR3 suppressed ALL cells proliferation. Further experiments proved that PAQR3 aggravates ferroptosis in ALL. In addition, AQR3 bound with Nrf2, and modulated its expression through ubiquitination in ALL. Finally, through rescue assays, it was demonstrated that Nrf2 overexpression reversed the effects of PAQR3 on cell proliferation and ferroptosis.
Findings from our work uncovered that PAQR3 inhibited proliferation and aggravated ferroptosis in ALL through modulation Nrf2 stability. This study suggested that PAQR3 may serve as an effective biological marker for ALL treatment.
急性淋巴细胞白血病（ALL）是一种常见的血液系统肿瘤，其特征是淋巴母细胞前体细胞的恶性增殖。许多重要的因素参与 ALL 的调控，包括蛋白质。PAQR3（也称为 RKTG）已被证明通过作为肿瘤抑制因子参与许多人类癌症。PAQR3 已被证明抑制人白血病细胞增殖并诱导细胞凋亡，但它在 ALL 中对细胞增殖和铁死亡的作用及其相关调节机制仍需要更多的探索。
通过定量逆转录聚合酶链反应（mRNA）或 Western blot（蛋白质）检测基因表达。通过细胞计数试剂盒-8 和 5-乙炔基-2-脱氧尿苷测定评估细胞增殖。通过商业试剂盒测试 ALL 细胞中 MDA、DCF 和细胞内游离 Fe 的水平。通过流式细胞术分析测定细胞凋亡。通过下拉实验验证 PAQR3 和核因子红细胞 2 相关因子 2（Nrf2）的结合能力。
首先在 ALL 患者和细胞系中评估了 PAQR3 的表达，发现其表达下调。证实 PAQR3 抑制 ALL 细胞增殖。进一步的实验证明，PAQR3 加重 ALL 中的铁死亡。此外，AQR3 与 Nrf2 结合，并通过泛素化调节其在 ALL 中的表达。最后，通过挽救实验证明，Nrf2 的过表达逆转了 PAQR3 对细胞增殖和铁死亡的影响。
我们的工作发现，PAQR3 通过调节 Nrf2 的稳定性抑制 ALL 中的增殖并加重铁死亡。这项研究表明，PAQR3 可能可作为 ALL 治疗的有效生物学标志物。
