Project description:Cuproptosis, a recently defined copper-dependent cell death, remains largely unexplored in tumor therapies, particularly in breast cancer. Our study demonstrates that triple-negative breast cancer (TNBC) bears a relative elevated copper levels and exhibit resistance to cuproptosis. Mechanistically, cooper activates AKT1 signaling pathway, which inhibits cuproptosis by directly phosphorylating ferredoxin-1 (FDX1), a key regulator involved in cuproptosis. AKT1-mediated FDX1 phosphorylation abrogates FDX1-induced cuproptosis and aerobic respiration, accompanied by promoting glycolysis. Consequently, combination of AKT1 inhibitors MK2206 and the copper ionophore elesclomol (ES) synergistically inhibits TNBC tumorigenesis both in vitro and in vivo. In summary, our findings uncover a critical mechanism underlying TNBC resistance to cuproptosis and propose a potential therapeutic approach for TNBC.
Project description:As the primary route for copper elimination, cholestasis raises questions about the role of copper in cholestatic liver injury and its specific molecular mechanisms. Our findings reveal that cholestasis-induced copper overload drives liver injury via taurocholic acid (TCA) -exacerbated and FDX1-mediated cuproptosis.
Project description:Alternative polyadenylation (APA) serves as a critical mechanism for shaping transcriptome diversity and modulating cancer therapeutic resistance. While lactate is a well-established metabolic signal in cancer progression, its role in APA regulation remains unclear. Here, we demonstrate that L-lactate-induced lactylation of NUDT21 drives transcriptomic reprogramming through APA modulation. NUDT21 lactylation enhances its interaction with CPSF6, facilitating CFIm complex formation and inducing 3′ untranslated region (UTR) lengthening of FDX1. Extension of the FDX1 3′ UTR attenuates its protein output, thereby conferring resistance to cuproptosis in esophageal squamous cell carcinoma (ESCC). Furthermore, we identify AARS1 as the lactylation “writer” catalyzing NUDT21 K23 lactylation, and HDAC2 as its enzymatic “eraser”. Clinically, elevated LDHA and NUDT21 levels correlate with reduced FDX1 expression and worse prognosis in ESCC patients. Notably, combined targeting of the lactate-NUDT21-FDX1-cuproptosis axis with the clinical LDHA inhibitor stiripentol and the copper ionophore elesclomol synergistically suppressed tumor growth. Collectively, our work identifies lactylated NUDT21 as a critical factor linking cellular metabolism to APA and proposes a promising therapeutic strategy for ESCC treatment.
Project description:Cuproptosis, a copper-dependent cell death process induced by excessive copper, represents an emerging therapeutic strategy in oncology. However, tumor specific molecular pathways regulating this process remain poorly defined. Here, we demonstrate that copper levels are elevated in lung adenocarcinoma (LUAD), and LUAD cell lines exhibit increased resistance to cuproptosis. Mechanistically,elevated copper stress promotes expression of the desuccinylase SIRT5 while reducing global succinylation in LUAD cells. Furthermore, we found that SIRT5 is a critical mediator of cuproptosis through the desuccinylation modification on Ferredoxin1(FDX1) protein at Lys84. This modification triggers TRIM8-mediated ubiquitination, leading to FDX1 proteasomal degradation and enhanced cuproptosis resistance. These results reveal the important role of SIRT5 in LUAD cuproptosis resistance. Notably, combining the SIRT5 inhibitor MC3482 with the cuproptosis inducer Elesclomol-Cu synergistically suppresses tumor growth in vitro and in
Project description:Single nucleotide polymorphisms in the FTO gene encoding a m6A demthylase are associated with obesity and cancer development. However, the functional role of FTO in the developemnt of progression of hepatocellular carcinoma (HCC) as a proteotypic obesity-associated cancer remains unclear. Here, we have generated mice with hepatic FTO deficiency (FTOL-KO) and subjected them to DEN induced HCC-development. FTOL-KO mice exhibit increased HCC burden. While control mice exhibit a dynamic regulation of FTO upon induction of liver damage, this response is abrogated in mice lacking FTO. Proteomic analyses revealed that liver damage-induced increases in FTO expression promotes m6A-demethylation of CUL4A reducing its protein expression. Functionally, knockdown of CUL4A restores the increased hepatocyte proliferation observed upon loss of FTO. Collectively, our study reveals a protective role for FTO-dependent dynamic m6A mRNA demethylation of CUL4A in the initiation of HCC development.
Project description:Cuproptosis is characterized by the aggregation of lipoylated components of the tricarboxylic acid cycle and subsequent loss of iron-sulfur cluster proteins as a unique copper-dependent form of regulated cell death. Dysregulation of copper homeostasis and resulting cuproptosis induction is an emerging area of interest for cancer therapy. However, mechanisms of cancer cell evasion of cuproptosis are not well understood. Here, we found that the cuproptosis process is accompanied by activation of the Wnt/β-catenin pathway. Mechanistically, copper binds to PDK1 and promotes its interaction with AKT, resulting in activation of the Wnt/β-catenin pathway and cancer stem cell (CSC) properties. Notably, aberrant activation of Wnt/β-catenin signaling conferred resistance of CSCs to cuproptosis. Further studies showed that the β-catenin/TCF4 transcriptional complex directly binds to the promoter region of ATP7B, a protein responsible for the efflux of copper ions from the cell, inducing its expression and reducing intracellular copper accumulation, thereby inhibiting cuproptosis. Knockdown of TCF4 or pharmacological blockade of the Wnt/β-catenin pathway increased the sensitivity of CSCs to elesclomol-Cu-induced cuproptosis. These findings reveal a link between copper homeostasis regulated by the Wnt/β-catenin pathway and cuproptosis sensitivity, and may provide a precision medicine strategy for cancer treatment by selectively inducing cuproptosis
Project description:Cuproptosis is characterized by the aggregation of lipoylated components of the tricarboxylic acid cycle and subsequent loss of iron-sulfur cluster proteins as a unique copper-dependent form of regulated cell death. Dysregulation of copper homeostasis and resulting cuproptosis induction is an emerging area of interest for cancer therapy. However, mechanisms of cancer cell evasion of cuproptosis are not well understood. Here, we found that the cuproptosis process is accompanied by activation of the Wnt/β-catenin pathway. Mechanistically, copper binds to PDK1 and promotes its interaction with AKT, resulting in activation of the Wnt/β-catenin pathway and cancer stem cell (CSC) properties. Notably, aberrant activation of Wnt/β-catenin signaling conferred resistance of CSCs to cuproptosis. Further studies showed that the β-catenin/TCF4 transcriptional complex directly binds to the promoter region of ATP7B, a protein responsible for the efflux of copper ions from the cell, inducing its expression and reducing intracellular copper accumulation, thereby inhibiting cuproptosis. Knockdown of TCF4 or pharmacological blockade of the Wnt/β-catenin pathway increased the sensitivity of CSCs to elesclomol-Cu-induced cuproptosis. These findings reveal a link between copper homeostasis regulated by the Wnt/β-catenin pathway and cuproptosis sensitivity, and may provide a precision medicine strategy for cancer treatment by selectively inducing cuproptosis
Project description:Cuproptosis is characterized by copper ion-induced polymerization of lipoylated proteins. Whether other proteins involved in cuprotosis also undergo polymerization in the presence of copper ions remains to be determined. In this study, we utilized three experimental approaches to identify novel copper-induced polymerized proteins associated with cuprotosis. In the first two approaches, melanoma A375 cells were treated with copper ionophores—either elesclomol (ES) or disulfiram (DSF) in combination with copper—prior to cell lysis. In the third approach, cell lysates were directly incubated with copper ions in vitro. The resulting lysates were then subjected to non-reducing gel electrophoresis to detect proteins that undergo copper-induced polymerization. We expect to identify new target proteins of copper ions and new participating and executing proteins of copper death through this method.
Project description:Fat mass and obesity-associated protein (FTO) can remove both the N6-methyladenosine (m6A) and N6, 2′-O-dimethyladenosine (m6Am) methylation marks that function in multiple aspects of posttranscriptional regulation. Here, we demonstrate that Zbtb48, a C2H2-zinc finger protein that functions in telomere maintenance, associates with FTO and binds both mRNA and the telomere-associated regulatory RNA TERRA to regulate the functional interactions of FTO with target transcripts. Specifically, depletion of Zbtb48 affects targeting of FTO to sites of m6A/m6Am modification, changes cellular m6A/m6Am levels and, consequently, alters decay rates of target RNAs. Zbtb48 ablation also accelerates growth of HCT-116 colorectal cancer cells and modulates FTO-dependent regulation of Metastasis-associated protein 1 (MTA1) transcripts by controlling the binding to MTA1 mRNA of the m6A reader IGF2BP2. Our findings thus uncover a previously unknown mechanism of posttranscriptional regulation in which Zbtb48 co-ordinates RNA-binding of the m6A/m6Am demethylase FTO to control expression of its target RNAs.
Project description:Fat mass and obesity-associated protein (FTO) can remove both the N6-methyladenosine (m6A) and N6, 2′-O-dimethyladenosine (m6Am) methylation marks that function in multiple aspects of posttranscriptional regulation. Here, we demonstrate that Zbtb48, a C2H2-zinc finger protein that functions in telomere maintenance, associates with FTO and binds both mRNA and the telomere-associated regulatory RNA TERRA to regulate the functional interactions of FTO with target transcripts. Specifically, depletion of Zbtb48 affects targeting of FTO to sites of m6A/m6Am modification, changes cellular m6A/m6Am levels and, consequently, alters decay rates of target RNAs. Zbtb48 ablation also accelerates growth of HCT-116 colorectal cancer cells and modulates FTO-dependent regulation of Metastasis-associated protein 1 (MTA1) transcripts by controlling the binding to MTA1 mRNA of the m6A reader IGF2BP2. Our findings thus uncover a previously unknown mechanism of posttranscriptional regulation in which Zbtb48 co-ordinates RNA-binding of the m6A/m6Am demethylase FTO to control expression of its target RNAs.