Department of Gastrointestinal Cancer Translational Research, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital & Institute, Beijing, P.R. China.
Department of Gastrointestinal Cancer Center, Ward I, Peking University Cancer Hospital & Institute, Beijing, P.R. China.
Clin Transl Med. 2024 Aug;14(8):e1754. doi: 10.1002/ctm2.1754.
Although it is traditionally believed that ATP binding cassette subfamily C member 2 (ABCC2) is a multidrug resistance-associated protein correlated with a worse prognosis, our previous and several other studies demonstrated the contrary to be true in gastric cancer (GC). We aim to explore the underlying mechanism of this discovery.
Our study utilized whole-exome sequencing (WES), RNA sequencing, and droplet digital PCR (ddPCR) analysis of 80 gastric cancer samples, along with comprehensive immunohistochemical (IHC) analysis of 1044 human GC tissue samples.By utilizing CRISPRCas9 to genetically modify cell lines with the ABCC2-24C > T (rs717620) point mutation and conducting dual-luciferase reporter assays, we identified that transcription factors SOX9 and ETS1 serve as negative regulators of ABCC2 expression. Seahorse assay and mass spectrometry were used to discover altered metabolic patterns. Gain and loss-of-function experiments in GC cell lines and preclinical models were carried out to validate ABCC2 biological function.
ABCC2 high expression correlated with better prognosis, and rs717620 can influence ABCC2 expression by disrupting the binding of ETS1 and SOX9. Gain and loss-of-function experiments in GC cell lines demonstrated amino acid deprivation reduces proliferation, migration, and drug resistance in ABCC2-high GC cells. ABCC2 leads to reduced intracellular amino acid pools and disruption of cellular energy metabolism. This phenomenon depended on ABCC2-mediated GSH extrusion, resulting in alterations in redox status, thereby increasing the cell's susceptibility to ferroptosis. Furthermore, patient-derived organoids and patient-derived tumor-like cell clusters were used to observe impact of ABCC2 on therapeutic effect. In the xenograft model with high ABCC2 expression, we observed that constricting amino acid intake in conjunction with GPX4 inactivation resulted in notable tumor regression.
Our findings demonstrate a significant role of ABCC2 in amino acid metabolism and ferroptosis by mediating GSH efflux in GC. This discovery underlines the potential of combining multiple ferroptosis targets as a promising therapeutic strategy for GC with high ABCC2 expression.
ABCC2 plays a crucial role in inducing metabolic vulnerability and ferroptosis in gastric cancer through enhanced glutathione efflux. The ABCC2 24C > T polymorphism is a key factor influencing its expression. These results highlight the potential of ABCC2 as a predictive biomarker and therapeutic target in gastric cancer.
尽管传统观点认为 ATP 结合盒亚家族 C 成员 2（ABCC2）是一种与预后不良相关的多药耐药相关蛋白，但我们之前和其他几项研究表明，在胃癌（GC）中情况恰恰相反。我们旨在探讨这一发现的潜在机制。
我们的研究利用全外显子组测序（WES）、RNA 测序和 80 个胃癌样本的液滴数字 PCR（ddPCR）分析，以及对 1044 个人 GC 组织样本的全面免疫组织化学（IHC）分析。通过利用 CRISPRCas9 对 ABCC2-24C>T（rs717620）点突变的细胞系进行基因修饰，并进行双荧光素酶报告基因检测，我们确定转录因子 SOX9 和 ETS1 是 ABCC2 表达的负调节因子。 Seahorse 测定和质谱分析用于发现改变的代谢模式。在 GC 细胞系和临床前模型中进行的增益和失活功能实验用于验证 ABCC2 的生物学功能。
ABCC2 高表达与预后较好相关，rs717620 可通过破坏 ETS1 和 SOX9 的结合来影响 ABCC2 的表达。GC 细胞系中的增益和失活功能实验表明，氨基酸剥夺会降低 ABCC2 高 GC 细胞的增殖、迁移和耐药性。ABCC2 导致细胞内氨基酸池减少，并破坏细胞能量代谢。这种现象取决于 ABCC2 介导的 GSH 外排，导致氧化还原状态改变，从而增加细胞对铁死亡的敏感性。此外，使用患者来源的类器官和患者来源的肿瘤样细胞簇来观察 ABCC2 对治疗效果的影响。在高 ABCC2 表达的异种移植模型中，我们观察到限制氨基酸摄入并同时抑制 GPX4 可导致明显的肿瘤消退。
我们的研究结果表明，ABCC2 通过介导 GSH 外排在 GC 中在氨基酸代谢和铁死亡中发挥重要作用。这项发现强调了联合多个铁死亡靶点作为具有高 ABCC2 表达的 GC 的有前途的治疗策略的潜力。
ABCC2 通过增强谷胱甘肽外排在胃癌中诱导代谢脆弱性和铁死亡，在胃癌中发挥关键作用。ABCC2 24C>T 多态性是影响其表达的关键因素。这些结果突出了 ABCC2 作为胃癌预测生物标志物和治疗靶点的潜力。
