背景:尽管传统上认为ATP结合盒亚家族C成员2(ABCC2)是一种与预后较差相关的多药耐药相关蛋白,我们以前的研究和其他几项研究表明,在胃癌(GC)中情况恰恰相反。我们的目标是探索这一发现的潜在机制。
方法:我们的研究利用全外显子组测序(WES),RNA测序,和液滴数字PCR(ddPCR)分析80例胃癌样本,以及对1044例人GC组织样品的综合免疫组织化学(IHC)分析。通过利用CRISPRCas9对ABCC2-24C>T(rs717620)点突变的细胞系进行遗传修饰,并进行双荧光素酶报告基因测定,我们发现转录因子SOX9和ETS1是ABCC2表达的负调节因子.海马测定和质谱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功能增益和丧失实验以验证ABCC2生物学功能。
结果:ABCC2高表达与较好的预后相关,rs717620可以通过破坏ETS1和SOX9的结合来影响ABCC2的表达。GC细胞系中的功能增益和丧失实验表明,氨基酸剥夺可减少增殖,迁移,ABCC2-highGC细胞的耐药性。ABCC2导致细胞内氨基酸库减少和细胞能量代谢破坏。这种现象取决于ABCC2介导的GSH挤压,导致氧化还原状态的改变,从而增加细胞对铁凋亡的敏感性。此外,患者来源的类器官和患者来源的肿瘤样细胞簇用于观察ABCC2对治疗效果的影响.在ABCC2高表达的异种移植模型中,我们观察到,减少氨基酸摄入与GPX4失活导致肿瘤明显消退.
结论:我们的研究结果表明,ABCC2通过介导GC中的GSH流出在氨基酸代谢和铁凋亡中具有重要作用。这一发现强调了结合多个铁死亡靶标作为具有高ABCC2表达的GC的有希望的治疗策略的潜力。
结论:ABCC2在通过增强谷胱甘肽外排诱导胃癌代谢易损性和铁凋亡中起关键作用。ABCC224C>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。
BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
CONCLUSIONS: 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.