bims-mibica Biomed News
on Mitochondrial bioenergetics in cancer
Issue of 2025–06–08
twenty-two papers selected by
Kelsey Fisher-Wellman, Wake Forest University



  1. bioRxiv. 2025 May 22. pii: 2025.05.17.654633. [Epub ahead of print]
      TP53 mutations confer treatment resistance across multiple cancers. Mechanisms of therapy resistance, beyond affecting transactivation of BCL-2 family genes, remain a mystery. Here, we report that TP53 mutated AML, triple negative breast cancer, and colorectal cancer escape therapy-induced apoptosis due to inability to activate caspase-3/7, despite having normal mitochondrial outer membrane permeabilization (MOMP) induction. To identify post-MOMP determinants of therapy resistance in TP53 mutated AML, we applied a multiomics approach - whole-genome CRISPR screen, bulk/single-cell RNAseq, and high-throughput drug screen. BIRC5 , encoding survivin, was selectively upregulated in paired hematopoietic stem/multipotent progenitor cells from TP53 mutant AML patients, with further enrichment after venetoclax-azacitidine (VenAza) relapse. Critically, BIRC5 was also upregulated in 17 of 26 TP53 mutant TCGA cancers. Genetic ablation of BIRC5 resensitized TP53 mutated AML to standard therapy by restoring caspase activation, validating therapeutic relevance. Importantly, targeting IAPs and survivin using clinically relevant inhibitors overcame VenAza resistance of TP53 mutant tumors in vivo , achieving sustained AML suppression. Combination with survivin inhibitors also overcame chemotherapy resistance in TP53 deficient solid cancers. Together, we discovered that wild-type TP53 is required in post-MOMP signaling and that BIRC5 dependency is an effective therapeutic target for poor prognosis, TP53 mutated cancers.
    DOI:  https://doi.org/10.1101/2025.05.17.654633
  2. bioRxiv. 2025 May 24. pii: 2025.05.20.655224. [Epub ahead of print]
      Acute myeloid leukemia (AML) is an aggressive hematological malignancy that has poor prognosis and high relapse rates with cytotoxic chemotherapeutics. Previously, we identified modulators of mitochondrial function, PS127-family compounds, that were cytotoxic to AML and were characterized by two predicted functions: apoptotic agonism and thioredoxin/glutathione reductase inhibition (T/GRi). Here, we uncovered a third critical predicted function: autophagic induction. A cheminformatics screening of ∼4.2 million compounds for molecules with high probability of these three functions yielded 93 hits, 81 of which were closely related to PS127-family molecules. In silico hits selected for validation selectively killed AML cells, activated apoptosis, required functional autophagy, and interfered with glutathione metabolism, confirming predicted functions. This increased pools of cytosolic and mitochondrial ROS and decreased oxygen consumption and ATP synthesis. Differential scanning fluorimetry implicated glutathione reductase as a direct target of these molecules. Structurally-unrelated compounds from different clusters caused the same phenotype, validating our structure-blind screening approach. Furthermore, strong synergy between these compounds and the AML treatment midostaurin underscores their therapeutic potential.
    DOI:  https://doi.org/10.1101/2025.05.20.655224
  3. bioRxiv. 2025 May 14. pii: 2025.05.13.651470. [Epub ahead of print]
      Serine metabolism is of growing biologic and therapeutic interest in cancer. Upregulation of the serine synthesis pathway (SSP) can fuel tumor growth, and cancers with this phenotype are often sensitive to SSP inhibitors. In parallel, dietary restriction of serine and glycine (SG) can suppress some cancers, but the determinants of sensitivity to this approach are poorly understood. This is especially true in acute myeloid leukemia (AML), where serine metabolism has been less explored. We report that a subset of human AML cell lines and primary samples are completely dependent on external serine, known as serine auxotrophy. These leukemias consistently suppressed the SSP enzyme PSAT1, failed to synthesize serine, responded to SG restriction in vivo , and were rescued by restoring PSAT1. We also found that AML with an SF3B1 K700E mutation showed additional dependence on the SSP enzyme PHGDH, that SG restriction synergized with venetoclax in serine auxotrophic AML, and that MECOM rearrangement was strongly associated with PSAT1 suppression and serine auxotrophy. These findings define a metabolically distinct AML subtype and nominate it for targeting by SG restriction.
    DOI:  https://doi.org/10.1101/2025.05.13.651470
  4. bioRxiv. 2025 May 24. pii: 2025.05.21.655274. [Epub ahead of print]
      Metabolic reprogramming is a hallmark of cancer, enabling tumor cells to meet their increased biosynthetic and energetic demands. While cells possess the capacity for de novo serine biosynthesis, most transformed cancer cells heavily depend on exogenous serine uptake to sustain their growth, yet the regulatory mechanisms driving this metabolic dependency remain poorly understood. Here, we uncover a novel mechanism by which Polo-like kinase 1 (PLK1), often overexpressed in prostate cancer, orchestrates a metabolic shift in serine and lipid metabolism through the phosphorylation of phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme of the serine synthesis pathway (SSP). We demonstrate that PLK1 phosphorylates PHGDH at three specific sites (S512, S513, S517), leading to a marked reduction in its protein level and enzymatic activity. This downregulation of SSP forces cancer cells to increase their reliance on exogenous serine uptake via the ASCT2 transporter, which, in turn, fuels the biosynthesis of lipids, including sphingolipids essential for tumor growth and survival. Targeting the SSP, serine uptake, or downstream lipid biosynthetic pathways may offer promising therapeutic avenues in PLK1-high advanced cancers.
    DOI:  https://doi.org/10.1101/2025.05.21.655274
  5. Sci Rep. 2025 Jun 03. 15(1): 19431
      Acute myeloid leukemia (AML) is the most prevalent type of leukemia in adults. Its heterogeneity, both between patients and within the same patient, is often a factor contributing to poor treatment outcomes. Despite advancements in AML biology and medicine in general, the standard AML treatment, the combination of cytarabine and daunorubicin, has remained the same for decades. Combination drug therapies are proven effective in achieving targeted efficacy while minimizing drug dosage and unintended side effects, a common problem for older AML patients. However, a systematic survey of the synergistic potential of drug-drug interactions in the context of AML pathology is lacking. Here, we examine the interactions between 15 commonly used cancer drugs across distinct AML cell lines and demonstrate that synergistic and antagonistic drug-drug interactions are widespread but not conserved across these cell lines. Notably, enasidenib and venetoclax, recently approved anticancer agents, exhibited the highest counts of synergistic interactions and the fewest antagonistic ones. In contrast, 6-Thioguanine, a purine analog, was involved in the highest number of antagonistic interactions. The interactions we report here cannot be attributed solely to the inherent natures of these three drugs, as each drug we examined was involved in several synergistic or antagonistic interactions in the cell lines we tested. Importantly, these drug-drug interactions are not conserved across cell lines, suggesting that the success of combination therapies might vary significantly depending on AML genotypes. For instance, we found that a single mutation in the TF1 cell line could dramatically alter drug-drug interactions, even turning synergistic interactions into antagonistic ones. Our findings provide a preclinical survey of drug-drug interactions, revealing the complexity of the problem.
    DOI:  https://doi.org/10.1038/s41598-025-03242-x
  6. bioRxiv. 2025 May 27. pii: 2025.05.13.653903. [Epub ahead of print]
      Human mitochondrial genome encodes essential genes for the oxidative phosphorylation (OXPHOS) complexes. These genes must be transcribed and translated in coordination with nuclear-encoded OXPHOS components to ensure correct stoichiometry during OXPHOS complex assembly in the mitochondria. While much is known about nuclear gene regulation during metabolic stresses like glucose deprivation, little is known about the accompanying transcriptional response in mitochondria. Using microscopy, roadblocking qPCR, and transcriptomics, we studied mitochondrial transcription in cells subjected to glucose deprivation, which is known to cause nuclear transcription downregulation and to activate the integrated stress response (ISR). We found that glucose deprivation stabilizes mitochondrial RNAs and slows mitochondrial transcription, effects that are quickly reversed with glucose reintroduction. Although transcriptomics revealed strong upregulation of the ISR, mitochondrial RNA stabilization was not upregulated by pharmacological activation of the ISR, but was promoted by inhibition of glycolysis, unveiling a direct connection between metabolism and regulation of mitochondrial gene expression.
    DOI:  https://doi.org/10.1101/2025.05.13.653903
  7. Proteomics. 2025 Jun 01. e13969
      Isolated complex I deficiency (ICD) is commonly associated with mitochondrial diseases and closely mimics subacute necrotising encephalomyelopathy. This disorder is characterised by metabolic perturbations that affect energy metabolism pathways, including fatty acid metabolism. Here, we examined the tissue-specific changes in fatty acid metabolism in the Ndufs4 KO mice by employing mass-spectrometry-based proteomics as a hypothesis-generating approach. We investigated proteomic changes in six tissues, including brain regions (brainstem, cerebellum, olfactory bulb), heart, kidney and liver, focusing on proteins involved in fatty acid metabolism. Although it is expected that most tissues, except for the brain, will utilise fatty acids as alternative energy sources when oxidative phosphorylation (OXPHOS) is deficient, our data revealed a more complex response. In the liver, fatty acid consumption (oxidation) was favoured as expected, but in the heart, fatty acid synthesis was favoured. In the kidney, proteins involved in almost all fatty acid metabolic processes (oxidation and synthesis) were downregulated. Our data demonstrate that metabolic adaptations in fatty acid metabolism to ICD were tissue-specific and often in opposing directions. Understanding the differential adaptations across tissues could inform future treatment targets for mitochondrial disorders.
    Keywords:  NDUFS4 knock out; complex I deficiency; fatty acid metabolism; proteomics
    DOI:  https://doi.org/10.1002/pmic.13969
  8. Biomaterials. 2025 May 26. pii: S0142-9612(25)00356-4. [Epub ahead of print]323 123437
      Metabolic reprogramming characterized by mitochondrial dysfunction and increased glycolysis is associated with aggressive tumor biology and poor therapeutic response. The interplays among NADPH oxidase (NOX)-mediated reactive oxygen species, regulation of glycolysis and oxidative phosphorylation (OXPHOS) in cancer cells suggest an opportunity to develop a new cancer therapy. We found that treatment with a hyaluronic acid nanoparticle encapsulated with GKT831 (HANP/GKT831), a NOX1/4 inhibitor, markedly inhibited the proliferation and invasion of cancer cells. Treated tumor cells had reduced levels of mitochondrial ROS, glycolysis, and OXPHOS. The combination of HANP/GKT831 with radiation reduced colony formation and invasion of tumor cells. The combination therapy markedly inhibited the levels of molecules in glycolysis, OXPHOS, and DNA repairing pathways in tumor cells. Systemic administrations of HANP/GKT831 combined with radiotherapy significantly inhibited tumor growth by 84.7 % in a mouse colorectal tumor model. Tumors treated with HANP/GKT831 and radiation had increased DNA damage and apoptotic cell death. Furthermore, the combined therapy increased intratumoral infiltration of activated cytotoxic T cells and M1 macrophages but reduced the levels of immunosuppressive fibroblasts and M2 macrophages. Our results support HANP/GKT831 as a cancer nanotherapeutic agent that induces redox and bioenergy stresses in cancer cells for enhanced therapeutic response to radiotherapy.
    Keywords:  Colorectal cancer; Glycolysis; Hyaluronic acid nanoparticle; Mitochondrial oxidative phosphorylation; NADPH oxidase inhibitor; Radiotherapy; Tumor metabolism
    DOI:  https://doi.org/10.1016/j.biomaterials.2025.123437
  9. bioRxiv. 2025 May 19. pii: 2025.05.16.654477. [Epub ahead of print]
      Lysosomal damage is an endogenous danger signal to the cell, but its significance for innate immunity and how specific signaling pathways are engaged by this stressor remain unclear. Here, we uncover an immune-inducible pathway that connects lysosomal damage to mitochondrial DNA (mtDNA) efflux and type I IFN production. Lysosomal damage elicits mitochondrial outer membrane permeabilization (MOMP) via BAK/BAX macropores; however, the inner mitochondrial membrane (IMM) prevents wholesale mtDNA release in resting cells. Priming with type II IFN (IFN-γ) induced the antibacterial effector apolipoprotein L-3 (APOL3), which upon transient lysosomal damage, targets mitochondria undergoing MOMP and selectively permeabilizes the IMM to enhance mtDNA release and activate cGAS/STING signaling. Biochemical and cellular reconstitution revealed that analogous to its bactericidal detergent-like mechanism, APOL3 solubilizes cardiolipin to permeabilize the IMM. Our findings illustrate how cells use an antibacterial protein to expedite the breakdown of endosymbiosis and facilitate a heightened response to injury and infection.
    DOI:  https://doi.org/10.1101/2025.05.16.654477
  10. Cell Death Discov. 2025 Jun 03. 11(1): 263
      BH3-only proteins are a subgroup of the pro-apoptotic Bcl-2 family proteins. They initiate apoptosis by interacting with the multidomain pro- and anti-apoptotic Bcl-2 family proteins. SYNE2 encodes multiple nesprin-2 (Nes2) isoforms of which the most abundant and the largest is the nuclear envelope protein nesprin-2 giant (Nes2G). Nes2G is a component of the nuclear envelope Linker of Nucleoskeleton and Cytoskeleton (LINC) complex that connects the nucleus and the cytoskeleton. Previously, we showed that Nes2 has pro-apoptotic activity. We now show that Nes2G can bind multidomain pro-apoptotic and anti-apoptotic Bcl-2 family proteins and contains two BH3-like motifs near its N- and C-termini. Molecular modeling predicts that these BH3-like motifs have amphipathic α-helix structures and can dock onto the canonical groove of Bax and anti-apoptotic proteins as well as the trigger site of Bax. A chimeric tBid with its BH3 domain replaced with the C-terminal Nes2 BH3-like domain binds to Bax in cells. Furthermore, Nes2 BH3-like motif-containing fragments from the N- and the C-termini bind both pro-apoptotic and anti-apoptotic Bcl-2 proteins and promote cytochrome c release (indicative of apoptosis). Our results suggest that Nes2 acts as a BH3-only protein that regulates apoptosis by binding to the multidomain Bcl-2 family proteins.
    DOI:  https://doi.org/10.1038/s41420-025-02534-5
  11. Oncogene. 2025 Jun 04.
      Sideroflexin 1 (SFXN1), a newly identified mitochondrial serine transporter, exhibits great potential to modulate mitochondrial function and promote tumor development. However, its role in bladder cancer (BLCA) remains unclear. Our study revealed that SFXN1 was enriched in clinical BLCA tissues, and high SFXN1 expression in BLCA was positively associated with the progression and poor prognosis. Further, SFXN1 deficiency remarkably suppressed the proliferation and metastasis of BLCA cells in vitro and in vivo, indicating an oncogenic role of SFXN1 in BLCA. Additionally, our results demonstrated that SFXN1 promotes metastasis through its unknown function of restraining PINK1 (PTEN-induced kinase 1)-dependent mitophagy rather than its classical role as a mitochondrial serine transporter to mediate one-carbon metabolism. Mechanistically, SFXN1 acted as a bridge to promote PINK1 degradation by interacting with PARL (presenilin-associated rhomboid-like protein) and MPP-β (mitochondrial processing peptidase-β), leading to mitophagy arrest. Notably, when mitophagy was restrained by highly-expressed SFXN1, mitochondrial reactive oxygen species were considerably enriched, thus activating TGF-β (transforming growth factor-β)-mediated epithelial-mesenchymal transition and promoting metastasis of BLCA cells. This study highlights SFXN1 as a novel promising therapeutic target for BLCA and identifies a new mitophagic modulator to improve our understanding of an association between mitophagy and BLCA progression. Schematic diagram of the proposed mechanism by which SFXN1 promotes bladder cancer metastasis by restraining PINK1-dependent mitophagy. SFXN1 is upregulated in BLCA tissues, and promotes BLCA metastasis through its unrevealed function of restraining PINK1-dependent mitophagy rather than its classical role as a mitochondrial serine transporter to promote cell proliferation. Specifically, SFXN1 acted as an essential bridging factor to promote PINK1 degradation by interacting with PARL and MPP-β on the IMM, leading to mitophagy arrest and mtROS accumulation, thus activated TGF-β-mediated EMT and promoted BLCA metastasis (This figure was created by Figdraw).
    DOI:  https://doi.org/10.1038/s41388-025-03460-7
  12. Clin Transl Med. 2025 May;15(5): e70362
       BACKGROUND: Despite rapid advances in HCC therapy, surgical resection is still the most effective treatment. However, postoperative relapse develops in a large population and the mechanism remains to be explored.
    METHODS: HCC resection samples were retrospectively collected from 12 nonrelapsed and 15 relapsed HCC patients for RNA sequencing. Liver-specific solute carrier family 39 member 1 (SLC39A1) knockout mice were generated by crossing Alb-Cre mice and SLC39A1flox/flox mice. Liver samples were examined for inflammation, fibrosis, proliferation, and apoptosis. Mitochondrial mass, autophagy, ROS, and mitochondrial membrane potential (MMP), were detected. Co-immunoprecipitation and molecular docking were used to identify protein interactions.
    RESULTS: SLC39A1 is highly expressed in relapsed HCC patients and negatively correlated with overall survival. Knockdown of SLC39A1 inhibited cell proliferation by arresting the cell cycle and promoted cell apoptosis, accompanied by suppressing autophagic flux. Mechanistically, SLC39A1 interacts with a member of the dynamin superfamily of GTPases dynamin-related protein 1 (DRP1), followed by facilitating mitochondrial fission and MMP reduction. Inhibition of DRP1 abolished SLC39A1-induced mitochondrial division and MMP depolarization, while overexpression of DRP1 reversed mitochondrial fusion and MMP hyperpolarization in SLC39A1 silenced cells, accompanied by recuperative cell proliferative ability. SLC39A1flox/flox,Alb-Cre mice displayed fewer tumour numbers and less liver damage compared with SLC39A1flox/flox mice. A specific peptide targeting SLC39A1 to disturb the combination of full-length SLC39A1 and DRP1 efficiently suppressed HCC progression.
    CONCLUSIONS: Our findings reveal a key role of SLC39A1-DRP1 interaction in HCC progression by disturbing mitochondrial quality control and providing a competitive peptide as a potential anti-tumour therapy.
    KEY POINTS: SLC39A1 correlates with HCC recurrence and HCC mortality. Interaction of SLC39A1 and DRP1 facilitates HCC by regulating mitochondrial quality control. Specific peptide targeting SLC39A1 efficiently prevents HCC progression.
    Keywords:  HCC relapse; cancer therapy; hepatocellular carcinoma; mitochondrial quality control
    DOI:  https://doi.org/10.1002/ctm2.70362
  13. Sci Adv. 2025 Jun 06. 11(23): eadt3552
      Clear cell renal cell carcinoma (ccRCC), the most common subtype of kidney cancer, exhibits notable metabolic reprogramming. We previously reported elevated HDAC7, a class II histone deacetylase, in ccRCC. Here, we demonstrate that HDAC7 promotes aggressive phenotypes and in vivo tumor progression in RCC. HDAC7 suppresses the expression of genes mediating branched-chain amino acid (BCAA) catabolism. Notably, lower expression of BCAA catabolism genes is strongly associated with worsened survival in ccRCC. Suppression of BCAA catabolism promotes expression of SNAIL1, a central mediator of aggressive phenotypes including migration and invasion. HDAC7-mediated suppression of the BCAA catabolic program promotes SNAI1 messenger RNA transcription via NOTCH signaling activation. Collectively, our findings provide innovative insights into the role of metabolic remodeling in ccRCC tumor progression.
    DOI:  https://doi.org/10.1126/sciadv.adt3552
  14. Nat Commun. 2025 May 31. 16(1): 5059
      Metabolic reactions play important roles in organisms such as providing energy, transmitting signals, and synthesizing biomacromolecules. Charting unknown metabolic reactions in cells is hindered by limited technologies, restricting the holistic understanding of cellular metabolism. Using mass spectrometry-resolved stable-isotope tracing metabolomics, we develop an isotopologue similarity networking strategy, namely IsoNet, to effectively deduce previously unknown metabolic reactions. The strategy uncovers ~300 previously unknown metabolic reactions in living cells and mice. Specifically, we elaborately chart the metabolic reaction network related to glutathione, unveiling three previously unreported reactions nestled within glutathione metabolism. Among these, a transsulfuration reaction, synthesizing γ-glutamyl-seryl-glycine directly from glutathione, underscores the role of glutathione as a sulfur donor. Functional metabolomics studies systematically characterize biochemical effects of previously unknown reactions in glutathione metabolism, showcasing their diverse functions in regulating cellular metabolism. Overall, these newly uncovered metabolic reactions fill gaps in the metabolic network maps, facilitating exploration of uncharted territories in cellular biochemistry.
    DOI:  https://doi.org/10.1038/s41467-025-60258-7
  15. Cancer Res. 2025 Jun 06.
      Normal tissues actively employ a phenomenon called cell competition to drive the elimination and replacement of less fit loser cells by fitter winner cells. This quality control mechanism promotes tissues health, by favouring the selective expansion of fitter cells. Indeed, through cell competition, many mutant cells are eliminated from tissues by fitter normal cells. However, some oncogenic mutations can turn cells into super-competitors that outcompete normal cells, promoting tumorigenic growth and metastasis. Several cellular stresses have been associated with the loser status such as oxidative stress, DNA damage responses, unfolded protein response and mitochondrial dysfunction. By affecting these pathways, metabolism and dietary choices can regulate cellular fitness and cell competition. However, how these pathways affect competitive interactions in vivo, during the early establishment of mutant clones, is relatively little understood. Recent work from Hemalatha and colleagues introduces real-time fluorescence ratio metric imaging of NAD(P)H and FAD, to investigate cellular redox status - live and over time, at single cell level - as cells compete in the mouse epidermis. Their work demonstrates that redox status changes dynamically during competition between cell carrying oncogenic mutations. It further shows that drugs that modulate mitochondrial metabolism and cellular redox are strong modulators of cell competition. The introduction of live redox imaging will prove a powerful tool to further dissect how metabolic states affect cell competition in normal physiology and in tumorigenesis.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-25-2374
  16. Genes Dis. 2025 Jul;12(4): 101452
      Despite numerous studies suggesting that RNA m6A transferase core complex including METTL3 and METTL14 play essential roles in both the initiation and maintenance of acute myeloid leukemia (AML), effective pharmacological targeting of these two proteins remains elusive. Here, we report the development and evaluation of a novel METTL3 degrader, ZW27941, designed to induce METTL3 degradation via the VHL-mediated proteasomal degradation pathway. ZW27941 exhibited potent and selective degradation of METTL3 and its binding partner METTL14, leading to significant anti-leukemic activity in AML cell lines. Furthermore, ZW27941 demonstrated synergistic or additive effects when combined with standard AML therapeutics, such as cytarabine and venetoclax. Our findings suggest that selective METTL3 degraders, exemplified by ZW27941, hold promise as a novel therapeutic approach for AML, particularly when used in combination with existing treatments to enhance efficacy and overcome resistance mechanisms.
    Keywords:  Acute myeloid leukemia; METTL3; PROTAC; Protein degradation; ZW27941
    DOI:  https://doi.org/10.1016/j.gendis.2024.101452
  17. bioRxiv. 2025 May 14. pii: 2025.05.13.653730. [Epub ahead of print]
      Quiescence (reversible cell-cycle arrest) and senescence (irreversible arrest) are challenging to distinguish due to a lack of specific biomarkers, yet both arise simultaneously after chemotherapy. While senescence suppresses tumors by limiting proliferation and recruiting the immune system, quiescent cancer cells evade future therapies and may resume proliferation. Here, we pair time-lapse imaging of cell-cycle dynamics with single-cell RNA-sequencing after etoposide treatment to differentiate these states, linking heterogeneous cell-cycle phenotypes to the transcriptomic landscape. We identify diverse senescent types (senotypes) and link them to two arrest pathways - a gradual path arising after a standard mitosis-to-G0 transition, and a rarer but direct path driven by a mitotic slip. Using pseudotime trajectory analysis, we find that senescent phenotypes begin to manifest early and gradually along the first trajectory, even in shallow quiescent cells. These data support a model wherein, following chemotherapy, quiescence and senescence exist on a continuum of cell-cycle withdrawal at a transcriptome-wide level.
    DOI:  https://doi.org/10.1101/2025.05.13.653730
  18. J Biol Chem. 2025 Jun 03. pii: S0021-9258(25)02184-2. [Epub ahead of print] 110334
      Mitochondrial tRNA processing defects have been associated with some clinical presentations including deafness. Especially, a deafness-linked m.7516delA mutation impaired the 5' end processing of RNA precursors and mitochondrial translation. In this study, we investigated the mechanism by m.7516delA mutation induced-deficiencies mitigate organellular and cellular integrity. The m.7516delA mutation downregulated the expression of nucleus encoding subunits and upregulated assemble factors of complex IV and altered the assembly and activities of oxidative phosphorylation (OXPHOS) complexes. The impairment of OXPHOS alleviated mitochondrial quality control processes, including the imbalanced mitochondrial dynamics via increasing fission with abnormal mitochondrial morphology. The m.7516delA mutation upregulated both ubiquitin-dependent and independent mitophagy pathways, evidenced by increasing levels of Parkin, BNIP3, NIX and MFN2-ubiquitination and altering interaction between MFN2 and MUL1 or Parkin, to facilitate the degradation of severely damaged mitochondria. Strikingly, the m.7516delA mutation activated integrated stress response (ISR) pathway, evidenced by upregulation of GCN2, P-GCN2, p-eIF2α, CHOP, ATF4 and elevating the nucleus-location of ATF5 to minimizes the damages in defective mitochondria. Both activation of ISR and PINK1/Parkin mitophagy pathways ameliorate the cell homeostasis via elevating the autophagy process and upregulating apoptotic pathways. Our findings provide new insights into underlying aberrant RNA processing-induced dysfunctions reprogrammed organelles and cellular integrity.
    DOI:  https://doi.org/10.1016/j.jbc.2025.110334
  19. Cell Rep. 2025 May 30. pii: S2211-1247(25)00550-9. [Epub ahead of print]44(6): 115779
      Progression following androgen-deprivation therapy (ADT) and the development of castration resistance is the leading cause of death among prostate cancer patients. Since there is currently a lack of known driver alterations associated with ADT resistance in castration-sensitive prostate cancer (CSPC), we investigated the critical role of crosstalk between cell signaling networks in early castration resistance. Our preclinical experiments and analyses of RNA sequencing data from clinical trials revealed nearly universal upregulation of BCL2 after ADT in CSPC cells. Mechanistically, our findings highlight a non-canonical function of BCL2 in orchestrating reciprocal signaling between the androgen receptor (AR)-BCL2 and phosphatidylinositol 3-kinase (PI3K) pathways, particularly upon ADT, potentially driving CSPC transformation into lethal castration-resistant prostate cancer (CRPC). Critically, our results provide a scientific rational that BCL2 inhibition should be trialed in CSPC in combination with ADT to impede or delay ADT-induced CSPC-to-CRPC transformation but may be ineffective if tested in patients who already have CRPC.
    Keywords:  ADT; AR; BCL 2; CP: Cancer; Hedgehog; PI3 kinase signaling; cellular plasticity; combination therapy; prostate cancer; signaling; venetoclax
    DOI:  https://doi.org/10.1016/j.celrep.2025.115779
  20. Cell Death Dis. 2025 Jun 03. 16(1): 432
      Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma (RCC), with a rising incidence worldwide. However, the mechanisms by which ccRCC evades immune surveillance remain incompletely understood. Our findings indicate that fumarate hydratase (FH) expression is significantly downregulated in ccRCC, resulting in fumarate accumulation, which is correlated with a poor prognosis in ccRCC patients. RNA sequencing analysis suggests that dimethyl fumarate (DMF), an FDA-approved fumarate analogue, may impact tumor immunity. Our further investigation reveals that both DMF and the FH inhibitor (FHIN1) can promote immune evasion in ccRCC by upregulating PD-L1. Pre-treatment of tumor cells with DMF notably inhibits the cytotoxic effect of T cells. Mechanistically, fumarate induces PD-L1 expression through succination of HIF-1α at C800, facilitating its interaction with importin α3, p300, and PKM2, which promotes HIF-1α nuclear localization and transcriptional activity. Moreover, combining DMF with PD-L1 blockade therapy significantly enhances the efficacy of immunotherapy and prolongs the survival of tumor-bearing mice. Taken together, our study elucidates a mechanism by which FH downregulation promotes immune evasion through the fumarate-HIF-1α/p300/PKM2-PD-L1 axis, providing a novel target, drug, and strategy to improve immunotherapy for ccRCC.
    DOI:  https://doi.org/10.1038/s41419-025-07752-4