Cell Death & Disease最新文献

Acute erythroleukemia (AEL) is a rare and highly aggressive subtype of acute myeloid leukemia (AML) that is often accompanied by splenomegaly in some patients. Using the Friend murine leukemia virus clone 57 (F-MuLV clone 57) mouse model, we observed lactate accumulation in the spleens of mice with late-stage disease. Proteomic profiling indicated dysregulation of the glycolysis/gluconeogenesis pathway and aberrant activity of its key enzymes. In vitro, lactate alone directly induced macrophage polarization to the pro-inflammatory M1 phenotype. This lactate-rich milieu reprograms macrophage function, favoring M1 polarization. A self-reinforcing cycle thus emerges in the AEL splenic microenvironment: lactate drives M1 polarization, and these M1 macrophages subsequently elevate their glycolytic activity, amplifying local lactate production that further promotes M1 polarization. In vivo, pharmacological inhibition of lactate production with Oxamate disrupted this cycle, reversed pathogenic M1 polarization, ameliorated splenomegaly, and extended survival. These results identify lactate as a key immunomodulatory factor in the splenic microenvironment that accelerates AEL progression. Targeting this lactate-driven metabolic-immune axis represents a novel adjunctive strategy for mitigating splenomegaly and disease progression in AEL.

Mitochondrial dysfunction-driven senescence is a central mechanism in the development of osteoarthritis (OA). Leucine-rich repeat kinase 2 (LRRK2), a multifunctional kinase implicated in maintaining mitochondrial homeostasis, has been examined in several inflammatory conditions. However, its role in regulating cellular senescence and its pathogenic contribution to OA remain insufficiently understood. To clarify the mechanism by which LRRK2 contributes to OA, RNA-seq and bioinformatics analysis were performed, followed by in vivo validation using a destabilization of medial meniscus (DMM) rat model in which LRRK2 was overexpressed via recombinant adeno-associated virus (rAAV). Complementary in vitro experiments were carried out to assess the impact of LRRK2 on mitochondrial dysfunction and senescence in chondrocytes. Our posttranscriptional analyses identified regulated factor influencing OA-related gene expression and revealed a strong association between LRRK2 and senescence-related regulatory genes in OA. rAAV-mediated LRRK2 overexpression accelerated chondrocyte senescence and worsened cartilage degeneration in DMM-induced OA. LRRK2 promoted HMGB1 upregulation by modulating GTPase activity, aggravating chondrocyte senescence. LRRK2 activated the cGAS-STING signaling pathway, increasing HMGB1 expression, exacerbating cellular senescence, and intensifying mitochondrial dysfunction. Treatment with the STING inhibitor H-151 partially mitigated the LRRK2-induced enhancement of chondrocyte senescence and mitochondrial impairment. This study demonstrates that LRRK2 drives chondrocyte senescence in OA by activating the cGAS-STING-HMGB1 axis, highlighting LRRK2 as a potential therapeutic target for OA.

Glioblastoma (GBM), the most common malignant brain tumor in adults, remains a highly lethal and incurable cancer, with a 5-year survival rate below 10%. Standard-of-care involves surgical resection followed by concurrent temozolomide chemotherapy and radiation treatment. While these interventions can effectively shrink tumors, they fail to eradicate all malignant cells. Small populations of GBM cells invariably survive and seed recurrent disease, leading to near-universal relapse and the formation of fatal recurrent tumors, typically within 1-2 years of treatment. Here, we investigated the metabolic features that define these surviving cell populations using ten patient-derived GBM models and matched orthotopic xenograft models exposed to a clinically relevant chemoradiotherapy regimen. By sampling living cells at defined treatment intervals and integrating ¹³C-glucose tracing, quantitative untargeted metabolomics, and nCounter metabolic gene expression profiling, we reconstructed the temporal evolution of glucose metabolism from therapy-naïve to post-treatment states. Across all models, GBM cells that evaded therapy-induced death exhibited a conserved and coordinated reorganization of glycolytic flux. These cells showed enhanced glucose uptake and elevated abundance of upper glycolytic enzymes such as HK1, while lower glycolytic enzymes, including ALDOA, GAPDH, ENO1, and LDHA, were suppressed, resulting in reduced lactate output. This bifurcation of glycolytic metabolism redirected carbon flux toward the pentose phosphate pathway and nucleotide biosynthesis, as well as mitochondrial metabolism, supported by the increased abundance of tricarboxylic acid cycle enzymes. Notably, these adaptations were conserved in recurrent patient-derived orthotopic xenograft tumors in vivo. Together, these findings reveal a fundamental and conserved metabolic state that defines GBM cells surviving chemoradiotherapy. This study deciphers a core metabolic architecture that enables tumor cell survival, persistence, and recurrence following therapy by shifting glycolytic flux away from lactate production to balance biosynthetic demands with mitochondrial metabolism.

Colorectal cancer (CRC) is one of the most frequently diagnosed malignant tumors. However, clear evidence explaining the regulatory mechanisms of programmed death ligand 1 (PD-L1) in CRC has been limited. To illustrate the function of YTH N⁶-methyladenosine (m⁶A) RNA binding protein F2 (YTHDF2), we conducted a comprehensive evaluation of expression profiling datasets from online databases and clinical samples. We used a subcutaneous immunodeficient mouse model to investigate the impact of YTHDF2 on CRC. Western blots, flow cytometry, PD-1/PD-L1 binding assay, and cell killing assay were used to assess the relationship between YTHDF2 and PD-L1. We used RNA sequencing, along with methylated RNA immunoprecipitation (MeRIP) and RNA binding protein immunoprecipitation (RIP) sequencing to analyze mRNA expression, m⁶A methylation levels, and YTHDF2 target transcripts. The m⁶A methylation locations of mRNAs were verified using sequence-based RNA adenosine methylation site predictor (SRAMP), MeRIP-qRT-PCR, RIP-qRT-PCR, and a dual-luciferase reporter system. YTHDF2 was upregulated in CRC tissues, and patients with higher YTHDF2 expression had a worse prognosis. The in vivo model showed that YTHDF2 promoted CRC growth, whereas in vitro experiments showed that inhibiting YTHDF2 expression did not affect cell proliferation, migration, or invasion. Mechanistically, interference with YTHDF2 reduced PD-L1 expression and the binding ability between PD-1 and PD-L1. The use of RNA-seq, MeRIP-seq, RIP-seq, and bioinformatics tools confirmed that the speckle type BTB/POZ protein (SPOP) mRNA was a YTHDF2 target and validated its m⁶A methylation sites. After YTHDF2 knockdown, SPOP mRNA stability increased, causing an increase in SPOP expression and a decrease in PD-L1 expression. This study demonstrated that YTHDF2 might upregulate PD-L1 expression by destabilizing m⁶A-containing SPOP mRNA and promote CRC development. The biological effect of the YTHDF2-SPOP-PD-L1 axis presented a promising target for CRC treatment and provided an approach to enhance the efficacy of anti-PD-1/PD-L1 therapy.

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its inflammatory sequel, metabolic dysfunction-associated steatohepatitis (MASH), pose escalating global health burdens, underscoring the urgent need to elucidate their molecular mechanisms and identify novel therapeutic targets. T-cell intracellular antigen 1 (TIA1), an RNA-binding protein and core organizer of stress granules (SGs), regulates post-transcriptional gene expression during cellular stress. However, its functional role in MASLD pathogenesis remains poorly understood. Hepatocyte-specific TIA1-knockout (TIA1-HKO) and wild-type control mice were subjected to three distinct diet-induced MASLD models. Parallel gain- and loss-of-function studies were conducted in PA-treated AML12 hepatocytes. RNA immunoprecipitation sequencing (RIP-seq), RIP-qPCR, fluorescence in situ hybridization (FISH), dual-luciferase reporter assays, and mRNA stability measurements were employed to map TIA1-sterol regulatory element binding transcription factor 1 (Srebf1) mRNA interactions and quantify translational repression. Pharmacological and genetic rescue experiments confirmed mechanistic findings. Integrated transcriptomic analysis of clinical specimens and murine models revealed significant TIA1 upregulation during MASLD progression. Hepatocyte-specific TIA1 deletion exacerbated dietary-induced steatosis, inflammation, and fibrosis. In vitro, TIA1 was essential for SGs assembly and maintenance of lipid homeostasis under lipotoxic stress. Mechanistically, TIA1 directly binds the 3' UTR of Srebf1 mRNA, sequestering it within SGs and repressing the translation of sterol regulatory element binding protein 1 (SREBP1)-a master transcriptional regulator of lipogenesis. Inhibition of SREBP1 activity rescued the metabolic perturbations induced by TIA1 ablation. This study identifies TIA1 as a crucial hepatoprotective factor that attenuates MASLD progression by orchestrating SGs-dependent translational control of Srebf1 mRNA. Impairment of the TIA1-SGs-SREBP1 axis accelerates steatohepatitis, highlighting its potential as a therapeutic target for metabolic liver diseases.TIA1 Constrains MASH Progression by Assembling Stress Granules to Suppress SREBP1-Driven Lipogenesis. This study delineates a hepatoprotective pathway centered on the RNA-binding protein TIA1. In response to metabolic stress. TIA1 nucleates SGs assembly and sequesters Srebf1 mRNA, leading to translational repression of the master lipogenic transcription factor SREBP1 and its downstream lipogenic program, thereby mitigating steatosis and subsequent inflammatory and fibrotic response.

Although glioblastoma (GBM) harbors multiple genetic abnormalities leading to cell cycle deregulation, a functional mitotic checkpoint is essential to prevent mitotic catastrophe and tumor cell death. Here, we identify the RNA-binding protein HNRNPH1 as a key post-transcriptional modulator of G2/M checkpoint-associated genes in GBM. HNRNPH1 is overexpressed in malignant cells, especially in the neural- and oligodendrocyte-progenitor-like state, and its expression levels are higher in non-hypoxic regions of the tumor. Knocking out HNRNPH1 causes aberrant splicing and downregulation of several genes involved in cell division. These molecular alterations are associated with G2/M cell cycle arrest, reduced cell proliferation, abnormal cell morphology, and increased nuclear fragmentation. Silencing HNRNPH1 in vivo inhibits the tumor growth of patient-derived GBM cell-originated intracranial xenografts and has significant survival benefits. Together, our results show the critical importance of HNRNPH1 in cell cycle progression and tumor growth, potentially impacting the development of novel strategies to treat GBM.

Monocyte-derived macrophages are usually recruited and play pivotal roles in establishing an immunosuppressive tumor microenvironment, and the interplay between tumor cells and tumor-associated macrophages (TAMs) is crucial for tumor development. However, the detailed mechanisms remain largely unelucidated in certain aggressive human cancers, such as melanoma. Here, through miRNA sequencing analysis, we found the microRNA miR-708-5p was highly enriched in melanoma exosomes, which was dependent on SFRS1. Treatment by melanoma exosomes facilitated M2 polarization of macrophages, while the polarized macrophages in turn promoted melanoma progression and metastasis both in vitro and in vivo. Mechanistically, miR-708-5p directly targets FOXN3, a member of the fork head/winged helix transcription factor family, and subsequently activates the PI3K/AKT/mTOR pathway in macrophages. Conversely, re-expression of FOXN3 in macrophages stably expressing miR-708-5p could reverse the impact on macrophages. In addition, downregulation of FOXN3 by miR-708-5p in macrophages reduced their phagocytic capacity and increased the secretion of IL-10 and TGF-β. Interestingly, we found that cellular retention of miR-708-5p could inhibit the proliferation and promote the apoptosis of melanoma cells, suggesting the necessity for secretion of this microRNA. In summary, our findings provide novel insights into the mechanism of melanoma-derived miR-708-5p in facilitating the formation of an immunosuppressive tumor microenvironment and indicate the potential of miR-708-5p and FOXN3 as therapeutic targets for the treatment of melanoma.

Malic enzyme 2 (ME2), a pivotal enzyme related to the tricarboxylic acid (TCA) cycle, has been implicated in multiple cancers due to its overexpression and metabolic role in regulating the NADP⁺/NADPH balance. Malic enzyme 2 has been reported to regulate mitochondrial biogenesis and fusion; however, whether malic enzyme 2 participates in mitophagy regulation has remained unclear. Here, we reported that malic enzyme 2 depletion enhances PINK1-Parkin-mediated mitophagy. Mechanistically, ME2 competes with the E3 ubiquitin ligase TRIM25, disrupting its binding with ATPase family AAA domain-containing protein 3 A (ATAD3A), a mitochondrial protein crucial for the degradation of PINK1. Loss of malic enzyme 2 strengthens the TRIM25-ATAD3A interaction, resulting in ATAD3A ubiquitination and proteasomal degradation. The consequent PINK1 accumulation drives mitophagy activation. Hyperactivated mitophagy caused by malic enzyme 2 knockdown disrupts mitochondrial homeostasis, which suppresses the proliferative capacity of hepatoma cells. Moreover, pharmacological inhibition of mitophagy partially rescued the suppressed cell proliferation in the malic enzyme 2-knockdown cells. Our findings reveal a previously unrecognized role of malic enzyme 2 in mitochondrial quality control and highlight the ME2-ATAD3A-PINK1 axis as a potential regulatory node for mitophagy modulation.

The ability of cancer cells to promote cellular proliferation by preferentially using glycolysis as primary source of energy has long been considered a hallmark of tumour metabolism. However, emerging evidence suggests a more complex situation with many tumours exhibiting a pronounced dependence on mitochondrial respiration through oxidative phosphorylation (OXPHOS) for their development and maintenance. In line with this, numerous studies have reported an upregulation of mitochondrial genes and OXPHOS components across multiple cancer types. Glioblastoma (GBM) is the most frequent and malignant brain tumour in adults, characterised by rapid proliferation, resistance to therapy and ability to recur. In addition to a profound genetic and molecular heterogeneity, GBM also exhibits strong metabolic heterogeneity with different grades of dependence on mitochondrial activity. Notably, the transcription factor Nuclear Respiratory Factor 1 (NRF-1), a key regulator of OXPHOS gene expression and mitochondrial functions, has recently been linked to GBM progression and poor prognosis. Che-1/Apoptosis Antagonising Transcription Factor (AATF) is a transcriptional regulator with a crucial role in several cancer types, where it contributes to tumorigenesis by promoting cell cycle arrest and apoptosis, as well as resistance to therapy. Here, we show that AATF expression correlates with clinical outcome in GBM patients. Moreover, we demonstrate that its depletion leads to cell cycle arrest, impaired mitochondrial respiration and disrupted mitochondrial architecture in GBM cells. Additionally, AATF-depleted cells exhibit a reduced ability to form colonies in vitro and tumour in vivo. At the molecular level, we provide evidence that AATF interacts with NRF-1 and is essential for NRF-1-mediated transcription of the OXPHOS genes by affecting RNA polymerase II recruitment and chromatin structure. Overall, our findings highlight a previously unrecognised role of AATF in GBM proliferation and mitochondrial metabolism supporting its potential as a target for therapeutic intervention.

The Aurora-A kinase and its major regulator TPX2 act as key players during mitosis. Both are overexpressed in tumors, and the Aurora-A/TPX2 complex has been proposed as a potential oncogenic holoenzyme. Evidence of Aurora-A non-mitotic roles in cancer, some of which depend on its nuclear accumulation in interphase and are independent from the kinase activity, is emerging. Indeed, many Aurora-A ATP-competitive inhibitors have shown limited efficacy in clinical trials so far, highlighting the need for novel strategies to inhibit Aurora-A. Interestingly, our recent results suggest an involvement of TPX2 also in the non-mitotic protumorigenic roles of Aurora-A, which makes the Aurora-A/TPX2 complex a promising target. We previously described Aurora-A/TPX2 protein-protein interaction inhibitors. Here, starting from in silico analyses, we identified a new compound, i.e., ATC12, which we validated in vitro as a molecule able to bind Aurora-A and to compete with TPX2. We investigated the effects of ATC12 in 2D cultures and 3D mammospheres of breast cancer cell lines, as well as in patient-derived organoids, and observed an impairment of Aurora-A/TPX2 interaction and a decrease in cell viability and proliferation. Altogether, our observations support the targeting of the Aurora-A/TPX2 complex as a promising strategy for the development of novel anti-cancer therapeutics.