PKM2 methylation by CARM1 activates aerobic glycolysis to promote tumorigenesis

Responsive plasmonic hybrid nanorods enables metabolism reprogramming via cuproptosis-photothermal combined cancer therapy

Abnormal tumor metabolism leads to tumor growth, metastasis, and recurrence, reprogramming tumor metabolism and activating potent anti-tumor immune response have been demonstrated to have good therapeutic effects on tumor elimination. Copper-based nanomaterials involved in cuproptosis show great prospects in these two aspects, but their efficiency is restricted by Cu homeostasis and the toxicity of the chelator. Here, the pH-responsive AuNRs@Cu2O core-shell plasmonic hybrid nanorods (ACNRs) have been successfully fabricated to realize microenvironment-controlled release at the tumor site for the combined therapy of cuproptosis and photothermal treatment. The AuNRs core exhibited excellent NIR-II photothermal property, which boost the intracellular concentration of copper to trigger severe cuproptosis and induce immunogenic cell death of tumor cells. In vivo studies demonstrated the ACNR exhibited efficient tumor therapy for primary, metastatic, and recurrent tumors. ACNRs-induced cuproptosis and PTT were capable of reprogramming energy metabolism, leading to a decreased production of lactic acid. This potential of metabolic reprogramming assisted in reshaping the immunosuppressive tumor microenvironment to facilitate the infiltration of immune cells and boost the immune responses triggered by PTT. The therapeutic mechanism was further verified by metabolomics analysis, which indicated that ACNRs + PTT treatment led to the inhibition of the Pentose Phosphate Pathway and Glycolysis pathways in tumor cells. The suppression of glycolytic reduced ATP synthesis, thereby hindering energy-dependent copper efflux, which in turn promoted cuproptosis. Taken together, this study offers promising insights for cuproptosis-based cancer treatment and sheds new light on nanomedicine-mediated metabolic modulation for future tumor therapy.

CARM1-induced lncRNA NEAT1 synchronously activates MYCN and GalNAcT-I to accelerate the progression of neuroblastoma

PURPOSE

Long non-coding RNAs (lncRNAs) play important roles in progression of neuroblastoma (NB). LncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been shown to affect the development of multiple tumors. However, the effect of NEAT1 on NB remain unclear. In this study, the new mechanisms whereby how NEAT1 influences tumor progression in NB was investigated.

METHODS

RT-qPCR, western blot, bioinformatics, cell growth, Transwell, and flow cytometric analyses were performed to determine how NEAT1 synchronously regulates the miR-873-5p/MYCN proto-oncogene(MYCN) and miR-873-5p/polypeptide N-acetylgalactosaminyltransferase 1(GalNAcT-I) axes to accelerate the progression of NB. NB-bearing animal models were established to evaluate the function of NEAT1 in NB. The relationships between transcription factor coactivatorassociated arginine methyltransferase 1 (CARM1) and NEAT1, NEAT1 and miR-873-5p, miR-873-5p and GalNacT-I or MYCN, were verified using luciferase reporter gene assay, respectively.

RESULTS

Our study revealed elevated levels of NEAT1 expression in NB cells and tissues which was associated with an advanced pathological stage and poor prognostic outcomes. According to in vitro gain- and loss- of function experiments, NEAT1 enhances progression of NB. NEAT1 silencing was found to inhibit NB proliferation in vivo. Mechanistically, to achieve upstream regulation, epigenetic downregulation of NEAT1 was achieved via the inhibition of CARM1. NEAT1 was found to positively regulate MYCN and GalNAcT-I levels as a competitive sponge of miR-873-5p.

CONCLUSION

Activity of the lncRNA NEAT1 can be triggered via CARM1, which synchronously promotes NB development via the miR-873-5p/MYCN and miR-873-5p/GalNAcT-I axes. These findings shed light on the novel molecular mechanisms underlying NB progression.

METTL1 mediates PKM m7G modification to regulate CD155 expression and promote immune evasion in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is characterized by poor responsiveness to immune evasion and immunotherapy. RNA 7-methylguanine (m7G) modification plays a key role in tumorigenesis. However, the mechanisms by which m7G-modified RNA metabolism affects tumor progression are not fully understood, nor is the contribution of m7G-modified RNA to the CRC immune microenvironment.

METHODS

The expression levels of Methyltransferase-like 1 (METTL1) and m7G in human tissues were determined. In this study, the effect of METTL1 on RNA m7G levels was evaluated, the effect of METTL1 on PKM mRNA modification was confirmed, the expression level of the PKM2 protein was detected, and the mechanism involved RT‒qPCR, Western blot, RNA stability analysis and RIP analysis. Lactate and H3K9 lactylation (H3K9la) induced by METTL1/PKM2 were analyzed via the extracellular acidification rate (ECAR) and lactic acid assays. Cut&Run was used to detect METTL1/PKM2-induced CD155 (PVR) transcription. In addition, METTL1 knockout mice were studied in vivo with CD155 blockers.

RESULTS

We demonstrated that m7G RNA METTL1 enhances PKM2 expression by acting on PKM mRNA, leading to tumor progression and increased glycolysis. Specifically, METTL1 mediates m7G methylation of PKM mRNA and enhances the expression of its encoded PKM2, which in turn enhances glycolysis, promotes H3K9la, and activates METTL1 transcription, creating a positive feedback loop. Moreover, increased PKM2 dimer expression and nuclear translocation activated CD155 expression and induced CRC immune evasion.

CONCLUSIONS

Our findings reveal a general mechanism by which METTL1/PKM2/H3K9la signaling regulates RNA metabolism and highlight METTL1 targeting as a potential strategy for CRC immunotherapy.

TIPE drives a cancer stem-like phenotype by promoting glycolysis via PKM2/HIF-1α axis in melanoma

TIPE (TNFAIP8) has been identified as an oncogene and participates in tumor biology. However, how its role in the metabolism of tumor cells during melanoma development remains unclear. Here, we demonstrated that TIPE promoted glycolysis by interacting with pyruvate kinase M2 (PKM2) in melanoma. We found that TIPE-induced PKM2 dimerization, thereby facilitating its translocation from the cytoplasm to the nucleus. TIPE-mediated PKM2 dimerization consequently promoted HIF-1α activation and glycolysis, which contributed to melanoma progression and increased its stemness features. Notably, TIPE specifically phosphorylated PKM2 at Ser 37 in an extracellular signal-regulated kinase (ERK)-dependent manner. Consistently, the expression of TIPE was positively correlated with the levels of PKM2 Ser37 phosphorylation and cancer stem cell (CSC) markers in melanoma tissues from clinical samples and tumor bearing mice. In summary, our findings indicate that the TIPE/PKM2/HIF-1α signaling pathway plays a pivotal role in promoting CSC properties by facilitating the glycolysis, which would provide a promising therapeutic target for melanoma intervention.

CARM1-mediated OGT arginine methylation promotes non-small cell lung cancer glycolysis by stabilizing OGT

O-GlcNAcylation catalyzed by O-GlcNAc transferase (OGT) plays an important role in the regulation of tumor glycolysis. However, the mechanism underlying OGT regulation remains largely unknown. Here, we showed that coactivator associated arginine methyltransferase 1 (CARM1) sensed changes of extracellular glucose levels in non-small cell lung cancer (NSCLC) cells. Increased glucose upregulated CARM1 and OGT. CARM1 methylated OGT at arginine 348, promoting its stability through binding of the deubiquitinase USP9X. The arginine methylation of OGT increased global O-GlcNAcylation levels, thereby promoting glycolysis in NSCLC cells. OGT arginine methylation also upregulated c-Myc expression and promoted the proliferation of NSCLC cells in vitro and in vivo. Consistently, OGT expression was positively correlated with CARM1 in human NSCLC samples. The present findings shed light on the mechanism underlying the stabilization of OGT by arginine methylation in response to changes of glucose concentration. The study also clarified the role of the CARM1-USP9X-OGT axis in glycolysis in NSCLC, providing a potential new target or therapeutic strategy in NSCLC.

Sanguinarine suppresses oral squamous cell carcinoma progression by targeting the PKM2/TFEB aix to inhibit autophagic flux

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies. However, there is no effective treatment for OSCC.

PURPOSE

This study aimed to identify a natural compound with significant efficacy against OSCC and elucidate its primary mechanism of action.

METHODS

An FDA-approved drug library and an MCE autophagy-related molecular compound library were screened through high-throughput screening to identify an effective natural compound against OSCC. The IC50 value of sanguinarine (Sang) in OSCC cells was determined using a CCK8 assay. Immunoblotting and immunofluorescence staining were used to assess the effect of Sang on autophagic flux in OSCC cells. Changes in the acidic lysosomal environment were evaluated using RFP-GFP-LC3B and LysoSensor Green DND-189. Furthermore, limited proteolysis-coupled mass spectrometry (LiP-MS) and virtual screening techniques were utilized to identify direct binding targets of Sang, which were subsequently validated by surface plasmon resonance (SPR) and microscale thermophoresis (MST). Molecular docking combined with molecular dynamics analysis identified the binding site between the target protein and Sang. In vitro and in vivo investigations with mutant plasmids confirmed this finding.

RESULTS

Screening led to the identification of the naturally occurring autophagy modulator Sang as a potent inhibitor of OSCC progression. Moreover, Sang impaired lysosomal function through reducing lysosomal-associated membrane proteins, inhibiting lysosomal proteolysis, and altering the lysosomal pH. These effects contributed to defects in autophagic clearance and subsequently suppressed OSCC progression. Notably, Sang bound the phenylalanine 26 (F26) residue in pyruvate kinase M2 (PKM2) and inhibited PKM2 enzymatic activity, subsequently suppressing transcription factor EB (TFEB) expression to inhibit lysosomal function and blocking autophagic flux in OSCC cells.

CONCLUSION

Our results demonstrate for the first time that Sang can suppress the PKM2/TFEB axis, and influence lysosomal function, thereby blocking autophagy and inhibiting the progression of OSCC, making it a promising therapeutic option for the treatment of OSCC.

A Peptide-Copper Self-Assembled Nanoparticle for Enhanced Cuproptosis by Metabolic Reprogramming in Tumor Cells

Cuproptosis is a type of metabolic cell death and exhibits great potential for cancer treatment. However, currently, most cuproptosis-based therapies are primarily effective in tumor cells reliant on mitochondrial respiration, limiting their broader application. The Warburg effect highlights that many tumors predominantly rely on glycolysis to meet their rapid metabolic demands, but glycolysis-dependent cells are less sensitive to copper ions than their mitochondrial-respiration-dependent counterparts, making it difficult to induce cuproptosis in these cells. Herein, we designed a copper-loaded peptide-based nanoparticle (MHRC@Cu) to enhance cuproptosis by metabolic reprogramming in a wider range of glycolysis-dependent tumor cells. Specifically, triggered by the acidic environment and laser irradiation, MHRC@Cu effectively released Cu2+ inside the cells. Then the peptide-conjugated probe (MHRC) reprogrammed glycolysis-dependent tumor cells, making them more dependent on mitochondrial respiration and increasing their sensitivity to copper ions. Additionally, the H2O2 generated by the photodynamic effect underwent Fenton reaction with Cu2+ in situ, producing highly toxic ·OH, which depleted GSH and disrupted copper efflux protein, thereby exacerbating copper deposition in cells. Through these synergistic mechanisms, MHRC@Cu significantly enhanced cuproptosis in glycolysis-dependent tumor cells, achieving up to 96% inhibition of tumor growth. This copper-loaded peptide-based nanoparticle offers a versatile and potent strategy for enhancing cuproptosis and may inspire the development of advanced self-assembled nanotherapeutic platforms.

Palmitic Acid Accelerates Endothelial Cell Injury and Cardiovascular Dysfunction via Palmitoylation of PKM2

High serum level of palmitic acid(PA) is implicated in pathogenesis of cardiovascular diseases. PA serves as the substrate for protein palmitoylation. However, it is still unknown whether palmitoylation is involved in PA-induced cardiovascular dysfunction. Here, in clinical cohort studies of 1040 patients with coronary heart disease, high level of PA is associated with risk of major adverse cardiovascular events (MACE) and death. In ApoE-/-mice, 10 mg/kg-1 PA treatment induces blood pressure elevation, cardiac contractile dysfunction, endothelial dysfunction and atherosclerotic plaqueformation. In endothelial cells, inhibition of palmitoylation bypalmitoyl-transferase inhibitor 2-BP eliminates PA-induced endothelial injury, whereas promotion of palmitoylation by depalmitoylase inhibitor ML349 exacerbates the harmful effect of PA. Palmitoyl-proteomics analysis identifies pyruvate kinase isozyme type M2 (PKM2) as the palmitoylated protein responsible for PA-induced endothelial injury, and Cys31 as the predominant palmitoylated site. PKM2-C31S mutants (cysteine replaced by serine) prevents PA-induced endothelial injury. Endothelial-specific AAV-C31S PKM2endo ameliorates cardiovascular dysfunction caused by PA in ApoE-/- mice. Mechanistically, PKM2-C31 palmitoylation impairs PKM2 tetramerization to inhibit its pyruvate kinase activity and endothelial glycolysis. Finally, zDHHC13 is identified as the palmitoyl acyltransferase of PKM2. In conclusion, these findings suggest that PKM2-C31 palmitoylation contributes to PA-induced endothelial injury and cardiovascular dysfunction.

RPF2 and CARM1 cooperate to enhance colorectal cancer metastasis via the AKT/GSK-3β signaling pathway

RPF2 plays a crucial role in promoting epithelial-mesenchymal transition (EMT) and regulating metastasis in colorectal cancer (CRC). By analyzing data from the TCGA and GEO databases, we observed significantly elevated RPF2 expression in CRC, which correlated with EMT markers. Further investigations using stable RPF2 overexpression and knockdown cell lines demonstrated that RPF2 facilitates EMT activation through the AKT/GSK-3β signaling pathway. Notably, CARM1 was identified as a key downstream effector of RPF2. Selective inhibition of CARM1 effectively suppressed the activation of the AKT/GSK-3β pathway and EMT induced by RPF2 overexpression. Both in vitro and in vivo experiments confirmed that RPF2 expression levels positively correlate with the metastatic potential of CRC cells. Moreover, treatment with a CARM1 inhibitor significantly reduced the invasive and migratory capabilities of RPF2-overexpressing cells. These findings suggest that RPF2 drives CRC metastasis by modulating EMT via the AKT/GSK-3β pathway, with CARM1 serving as a critical mediator, offering potential therapeutic targets for CRC.

Dihydroartemisinin enhances the anti-tumour effect of photodynamic therapy by targeting PKM2-mediated glycolysis in oesophageal cancer cell

Photodynamic therapy (PDT) has been demonstrated to provide immediate relief of oesophageal cancer patients' re-obstruction and extend their lifespan. However, tumour regrowth may occur after PDT due to enhanced aerobic glycolysis. Previous research has confirmed the inhibitory effect of Dihydroartemisinin (DHA) on aerobic glycolysis. Therefore, the current study intends to investigate the function and molecular mechanism of DHA targeting tumour cell aerobic glycolysis in synergia PDT. The combined treatment significantly suppressed glycolysis in vitro and in vivo compared to either monotherapy. Exploration of the mechanism through corresponding experiments revealed that pyruvate kinase M2 (PKM2) was downregulated in treated cells, whereas overexpression of PKM2 nullified the inhibitory effects of DHA and PDT. This study proposes a novel therapeutic strategy for oesophageal cancer through DHA-synergized PDT treatment, targeting inhibit PKM2 to reduce tumour cell proliferation and metastasis.

Arginine methylation-dependent TRIM47 stability mediated by CARM1 promotes the metastasis of hepatocellular carcinoma

The tripartite motif (TRIM) protein family has been shown to play important roles in the occurrence and development of various tumors. However, the biological functions of TRIM47 and its regulatory mechanism in hepatocellular carcinoma (HCC) remain unexplored. Here, we showed that TRIM47 was upregulated in HCC tissues compared with adjacent normal tissues, especially at advanced stages, and associated with poor prognosis in HCC patients. Functional studies demonstrated that TRIM47 enhanced the migration and invasion ability of HCC cells in vitro and in vivo. Mechanistically, TRIM47 promotes HCC metastasis through interacting with SNAI1 and inhibiting its degradation by proteasome. Moreover, TRIM47 was di-methylated by CARM1 at its arginine 210 (R210) and arginine 582 (R582), which protected TRIM47 from the ubiquitination and degradation mediated by E3 ubiquitin ligase complex CRL4CRBN. Collectively, our study reveals a pro-metastasis role of TRIM47 in HCC, unveils a unique mechanism controlling TRIM47 stability by CARM1 mediated arginine methylation, and highlights the role of the CARM1-CRL4CRBN-TRIM47-SNAI1 axis in HCC metastasis. This work may provide potential therapeutic targets for metastatic HCC treatment.

Replenishment of TCA cycle intermediates and long-noncoding RNAs regulation in breast cancer

The tricarboxylic acid (TCA) cycle is an essential interface that coordinates cellular metabolism and is as a primary route determining the fate of a variety of fuel sources, including glucose, fatty acid and glutamate. The crosstalk of nutrients replenished TCA cycle regulates breast cancer (BC) progression by changing substrate levels-induced epigenetic alterations, especially the methylation, acetylation, succinylation and lactylation. Long non-coding RNAs (lncRNA) have dual roles in inhibiting or promoting energy reprogramming, and so altering the metabolic flux of fuel sources to the TCA cycle, which may regulate epigenetic modifications at the cellular level of BC. This narrative review discussed the central role of the TCA cycle in interconnecting numerous fuels and the induced epigenetic modifications, and the underlying regulatory mechanisms of lncRNAs in BC.

Tetrameric, active PKM2 inhibits IP3 receptors, potentially requiring GRP75 as an additional interaction partner

Pyruvate kinase M2 (PKM2) is a key glycolytic enzyme interacting with the inositol 1,4,5-trisphosphate receptor (IP3R). This interaction suppresses IP3R-mediated cytosolic [Ca2+] rises. As PKM2 exists in monomeric, dimeric and tetrameric forms displaying different properties including catalytic activity, we investigated the molecular determinants of PKM2 enabling its interaction with IP3Rs. Treatment of HeLa cells with TEPP-46, a compound stabilizing the tetrameric form of PKM2, increased both its catalytic activity and the suppression of IP3R-mediated Ca2+ signals. Consistently, in PKM2 knock-out HeLa cells, PKM2C424L, a tetrameric, highly active PKM2 mutant, but not inactive PKM2K270M or the less active PKM2K305Q, suppressed IP3R-mediated Ca2+ release. Surprisingly, however, in vitro assays did not reveal a direct interaction between purified PKM2 and either the purified Fragment 5 of IP3R1 (a.a. 1932-2216) or the therein located D5SD peptide (a.a. 2078-2098 of IP3R1), the presumed interaction sites of PKM2 on the IP3R. Moreover, on-nucleus patch clamp of heterologously expressed IP3R1 in DT40 cells devoid of endogenous IP3Rs did not reveal any functional effect of purified wild-type PKM2, mutant PKM2 or PKM1 proteins. These results indicate that an additional factor mediates the regulation of the IP3R by PKM2 in cellulo. Immunoprecipitation of GRP75 using HeLa cell lysates co-precipitated IP3R1, IP3R3 and PKM2. Moreover, the D5SD peptide not only disrupted PKM2:IP3R, but also PKM2:GRP75 and GRP75:IP3R interactions. Our data therefore support a model in which catalytically active, tetrameric PKM2 suppresses Ca2+ signaling via the IP3R through a multiprotein complex involving GRP75.

The emerging role of CARM1 in cancer

Coactivator-associated arginine methyltransferase 1 (CARM1), pivotal for catalyzing arginine methylation of histone and non-histone proteins, plays a crucial role in developing various cancers. CARM1 was initially recognized as a transcriptional coregulator by orchestrating chromatin remodeling, transcription regulation, mRNA splicing and stability. This diverse functionality contributes to the recruitment of transcription factors that foster malignancies. Going beyond its established involvement in transcriptional control, CARM1-mediated methylation influences a spectrum of biological processes, including the cell cycle, metabolism, autophagy, redox homeostasis, and inflammation. By manipulating these physiological functions, CARM1 becomes essential in critical processes such as tumorigenesis, metastasis, and therapeutic resistance. Consequently, it emerges as a viable target for therapeutic intervention and a possible biomarker for medication response in specific cancer types. This review provides a comprehensive exploration of the various physiological functions of CARM1 in the context of cancer. Furthermore, we discuss potential CARM1-targeting pharmaceutical interventions for cancer therapy.

Blocking CXCR4-CARM1-YAP axis overcomes osteosarcoma doxorubicin resistance by suppressing aerobic glycolysis

Osteosarcoma, recognized for its aggressiveness and resistance to chemotherapy, notably doxorubicin, poses significant treatment challenges. This comprehensive study investigated the CXCR4-CARM1-YAP signaling axis and its pivotal function in controlling aerobic glycolysis, which plays a crucial role in doxorubicin resistance. Detailed analysis of Dox-resistant 143b/MG63-DoxR cells has uncovered the overexpression of CXCR4. Utilizing a combination of molecular biology techniques including gene silencing, aerobic glycolysis assays such as Seahorse experiments, RNA sequencing, and immunofluorescence staining. The study provides insight into the mechanistic pathways involved. Results demonstrated that disrupting CXCR4 expression sensitizes cells to doxorubicin-induced apoptosis and alters glycolytic activity. Further RNA sequencing revealed that CARM1 modulated this effect through its influence on glycolysis, with immunofluorescence of clinical samples confirming the overexpression of CXCR4 and CARM1 in drug-resistant tumors. Chromatin immunoprecipitation studies further highlighted the role of CARM1, showing it to be regulated by methylation at the H3R17 site, which in turn affected YAP expression. Crucially, in vivo experiments illustrated that CARM1 overexpression could counteract the tumor growth suppression that resulted from CXCR4 inhibition. These insights revealed the intricate mechanisms at play in osteosarcoma resistance to doxorubicin and pointed toward potential new therapeutic strategies that could target this metabolic and signaling network to overcome drug resistance and improve patient outcomes.

CARM1 phosphorylation at S595 by p38γ MAPK drives ROS-mediated cellular senescence

CARM1 is predominantly localized in the nucleus and plays a pivotal role in maintaining mitochondrial homeostasis by regulating gene expression. It suppresses mitochondrial biogenesis by downregulating PGC-1α and TFAM expression, while promoting mitochondrial fission through increased DNM1L expression. Under oxidative stress, CARM1 translocates to the cytoplasm, where it directly methylates DRP1 and accelerates mitochondrial fission, enhancing reactive oxygen species (ROS) production. Cytoplasmic localization of CARM1 is facilitated by its phosphorylation at S595 by ROS-activated p38γ MAPK, creating a positive feedback loop. Consequently, cytoplasmic CARM1 contributes to cellular senescence by altering mitochondrial dynamics and increasing ROS levels. This observation was supported by the increased cytoplasmic CARM1 levels and disrupted mitochondrial dynamics in the transformed 10T1/2 cells. Moreover, CARM1 inhibitors not only inhibit the proliferation of cancer cells but also induce apoptotic death in senescent cells. These findings highlight the potential of CARM1 inhibitors, particularly those targeting cytoplasmic functions, as novel strategies for eliminating cancer and senescent cells.

Epigenetic reader ZMYND11 noncanonical function restricts HNRNPA1-mediated stress granule formation and oncogenic activity

Epigenetic readers frequently affect gene regulation, correlate with disease prognosis, and hold significant potential as therapeutic targets for cancer. Zinc finger MYND-type containing 11 (ZMYND11) is notably recognized for reading the epigenetic marker H3.3K36me3; however, its broader functions and mechanisms of action in cancer remain underexplored. Here, we report that ZMYND11 downregulation is prevalent across various cancers and profoundly correlates with poorer outcomes in prostate cancer patients. Depletion of ZMYND11 promotes tumor cell growth, migration, and invasion in vitro, as well as tumor formation and metastasis in vivo. Mechanistically, we discover that ZMYND11 exhibits tumor suppressive roles by recognizing arginine-194-methylated HNRNPA1 dependent on its MYND domain, thereby retaining HNRNPA1 in the nucleus and preventing the formation of stress granules in the cytoplasm. Furthermore, ZMYND11 counteracts the HNRNPA1-driven increase in the PKM2/PKM1 ratio, thus mitigating the aggressive tumor phenotype promoted by PKM2. Remarkably, ZMYND11 recognition of HNRNPA1 can be disrupted by pharmaceutical inhibition of the arginine methyltransferase PRMT5. Tumors with low ZMYND11 expression show sensitivity to PRMT5 inhibitors. Taken together, our findings uncover a previously unexplored noncanonical role of ZMYND11 as a nonhistone methylation reader and underscore the critical importance of arginine methylation in the ZMYND11-HNRNPA1 interaction for restraining tumor progression, thereby proposing novel therapeutic targets and potential biomarkers for cancer treatment.

The NRF2-CARM1 axis links glucose sensing to transcriptional and epigenetic regulation of the pentose phosphate pathway in gastric cancer

Cancer cells autonomously alter metabolic pathways in response to dynamic nutrient conditions in the microenvironment to maintain cell survival and proliferation. A better understanding of these adaptive alterations may reveal the vulnerabilities of cancer cells. Here, we demonstrate that coactivator-associated arginine methyltransferase 1 (CARM1) is frequently overexpressed in gastric cancer and predicts poor prognosis of patients with this cancer. Gastric cancer cells sense a reduced extracellular glucose content, leading to activation of nuclear factor erythroid 2-related factor 2 (NRF2). Subsequently, NRF2 mediates the classic antioxidant pathway to eliminate the accumulation of reactive oxygen species induced by low glucose. We found that NRF2 binds to the CARM1 promoter, upregulating its expression and triggering CARM1-mediated hypermethylation of histone H3 methylated at R arginine 17 (H3R17me2) in the glucose-6-phosphate dehydrogenase gene body. The upregulation of this dehydrogenase, driven by the H3R17me2 modification, redirects glucose carbon flux toward the pentose phosphate pathway. This redirection contributes to nucleotide synthesis (yielding nucleotide precursors, such as ribose-5-phosphate) and redox homeostasis and ultimately facilitates cancer cell survival and growth. NRF2 or CARM1 knockdown results in decreased H3R17me2a accompanied by the reduction of glucose-6-phosphate dehydrogenase under low glucose conditions. Collectively, this study reveals a significant role of CARM1 in regulating the tumor metabolic switch and identifies CARM1 as a potential therapeutic target for gastric cancer treatment.

Hydrogen sulfide coordinates glucose metabolism switch through destabilizing tetrameric pyruvate kinase M2

Most cancer cells reprogram their glucose metabolic pathway from oxidative phosphorylation to aerobic glycolysis for energy production. By reducing enzyme activity of pyruvate kinase M2 (PKM2), cancer cells attain a greater fraction of glycolytic metabolites for macromolecule synthesis needed for rapid proliferation. Here we demonstrate that hydrogen sulfide (H2S) destabilizes the PKM2 tetramer into monomer/dimer through sulfhydration at cysteines, notably at C326, leading to reduced PKM2 enzyme activity and increased PKM2-mediated transcriptional activation. Blocking PKM2 sulfhydration at C326 through amino acid mutation stabilizes the PKM2 tetramer and crystal structure further revealing the tetramer organization of PKM2-C326S. The PKM2-C326S mutant in cancer cells rewires glucose metabolism to mitochondrial respiration, significantly inhibiting tumor growth. In this work, we demonstrate that PKM2 sulfhydration by H2S inactivates PKM2 activity to promote tumorigenesis and inhibiting this process could be a potential therapeutic approach for targeting cancer metabolism.

A Tutorial Review of Labeling Methods in Mass Spectrometry-Based Quantitative Proteomics

Recent advancements in mass spectrometry (MS) have revolutionized quantitative proteomics, with multiplex isotope labeling emerging as a key strategy for enhancing accuracy, precision, and throughput. This tutorial review offers a comprehensive overview of multiplex isotope labeling techniques, including precursor-based, mass defect-based, reporter ion-based, and hybrid labeling methods. It details their fundamental principles, advantages, and inherent limitations along with strategies to mitigate the limitation of ratio-distortion. This review will also cover the applications and latest progress in these labeling techniques across various domains, including cancer biomarker discovery, neuroproteomics, post-translational modification analysis, cross-linking MS, and single-cell proteomics. This Review aims to provide guidance for researchers on selecting appropriate methods for their specific goals while also highlighting the potential future directions in this rapidly evolving field.

PRMT5-mediated FUBP1 methylation accelerates prostate cancer progression

Strategies beyond hormone-related therapy need to be developed to improve prostate cancer mortality. Here, we show that FUBP1 and its methylation were essential for prostate cancer progression, and a competitive peptide interfering with FUBP1 methylation suppressed the development of prostate cancer. FUBP1 accelerated prostate cancer development in various preclinical models. PRMT5-mediated FUBP1 methylation, regulated by BRD4, was crucial for its oncogenic effect and correlated with earlier biochemical recurrence in our patient cohort. Suppressed prostate cancer progression was observed in various genetic mouse models expressing the FUBP1 mutant deficient in PRMT5-mediated methylation. A competitive peptide, which was delivered through nanocomplexes, disrupted the interaction of FUBP1 with PRMT5, blocked FUBP1 methylation, and inhibited prostate cancer development in various preclinical models. Overall, our findings suggest that targeting FUBP1 methylation provides a potential therapeutic strategy for prostate cancer management.

Transcriptional regulation and post-translational modifications in the glycolytic pathway for targeted cancer therapy

Cancer cells largely rely on aerobic glycolysis or the Warburg effect to generate essential biomolecules and energy for their rapid growth. The key modulators in glycolysis including glucose transporters and enzymes, e.g. hexokinase 2, enolase 1, pyruvate kinase M2, lactate dehydrogenase A, play indispensable roles in glucose uptake, glucose consumption, ATP generation, lactate production, etc. Transcriptional regulation and post-translational modifications (PTMs) of these critical modulators are important for signal transduction and metabolic reprogramming in the glycolytic pathway, which can provide energy advantages to cancer cell growth. In this review we recapitulate the recent advances in research on glycolytic modulators of cancer cells and analyze the strategies targeting these vital modulators including small-molecule inhibitors and microRNAs (miRNAs) for targeted cancer therapy. We focus on the regulation of the glycolytic pathway at the transcription level (e.g., hypoxia-inducible factor 1, c-MYC, p53, sine oculis homeobox homolog 1, N6-methyladenosine modification) and PTMs (including phosphorylation, methylation, acetylation, ubiquitination, etc.) of the key regulators in these processes. This review will provide a comprehensive understanding of the regulation of the key modulators in the glycolytic pathway and might shed light on the targeted cancer therapy at different molecular levels.

Involvement of tumor immune microenvironment metabolic reprogramming in colorectal cancer progression, immune escape, and response to immunotherapy

Metabolic reprogramming is a k`ey hallmark of tumors, developed in response to hypoxia and nutrient deficiency during tumor progression. In both cancer and immune cells, there is a metabolic shift from oxidative phosphorylation (OXPHOS) to aerobic glycolysis, also known as the Warburg effect, which then leads to lactate acidification, increased lipid synthesis, and glutaminolysis. This reprogramming facilitates tumor immune evasion and, within the tumor microenvironment (TME), cancer and immune cells collaborate to create a suppressive tumor immune microenvironment (TIME). The growing interest in the metabolic reprogramming of the TME, particularly its significance in colorectal cancer (CRC)-one of the most prevalent cancers-has prompted us to explore this topic. CRC exhibits abnormal glycolysis, glutaminolysis, and increased lipid synthesis. Acidosis in CRC cells hampers the activity of anti-tumor immune cells and inhibits the phagocytosis of tumor-associated macrophages (TAMs), while nutrient deficiency promotes the development of regulatory T cells (Tregs) and M2-like macrophages. In CRC cells, activation of G-protein coupled receptor 81 (GPR81) signaling leads to overexpression of programmed death-ligand 1 (PD-L1) and reduces the antigen presentation capability of dendritic cells. Moreover, the genetic and epigenetic cell phenotype, along with the microbiota, significantly influence CRC metabolic reprogramming. Activating RAS mutations and overexpression of epidermal growth factor receptor (EGFR) occur in approximately 50% and 80% of patients, respectively, stimulating glycolysis and increasing levels of hypoxia-inducible factor 1 alpha (HIF-1α) and MYC proteins. Certain bacteria produce short-chain fatty acids (SCFAs), which activate CD8+ cells and genes involved in antigen processing and presentation, while other mechanisms support pro-tumor activities. The use of immune checkpoint inhibitors (ICIs) in selected CRC patients has shown promise, and the combination of these with drugs that inhibit aerobic glycolysis is currently being intensively researched to enhance the efficacy of immunotherapy.

CARM1 hypermethylates the NuRD chromatin remodeling complex to promote cell cycle gene expression and breast cancer development

Protein arginine methyltransferase CARM1 has been shown to methylate a large number of non-histone proteins, and play important roles in gene transcriptional activation, cell cycle progress, and tumorigenesis. However, the critical substrates through which CARM1 exerts its functions remain to be fully characterized. Here, we reported that CARM1 directly interacts with the GATAD2A/2B subunit in the nucleosome remodeling and deacetylase (NuRD) complex, expanding the activities of NuRD to include protein arginine methylation. CARM1 and NuRD bind and activate a large cohort of genes with implications in cell cycle control to facilitate the G1 to S phase transition. This gene activation process requires CARM1 to hypermethylate GATAD2A/2B at a cluster of arginines, which is critical for the recruitment of the NuRD complex. The clinical significance of this gene activation mechanism is underscored by the high expression of CARM1 and NuRD in breast cancers, and the fact that knockdown CARM1 and NuRD inhibits cancer cell growth in vitro and tumorigenesis in vivo. Targeting CARM1-mediated GATAD2A/2B methylation with CARM1 specific inhibitors potently inhibit breast cancer cell growth in vitro and tumorigenesis in vivo. These findings reveal a gene activation program that requires arginine methylation established by CARM1 on a key chromatin remodeler, and targeting such methylation might represent a promising therapeutic avenue in the clinic.

Pyruvate Kinase M2: A Potential Regulator of Cardiac Injury Through Glycolytic and Non-glycolytic Pathways

ABSTRACT

Adult animals are unable to regenerate heart cells due to postnatal cardiomyocyte cycle arrest, leading to higher mortality rates in cardiomyopathy. However, reprogramming of energy metabolism in cardiomyocytes provides a new perspective on the contribution of glycolysis to repair, regeneration, and fibrosis after cardiac injury. Pyruvate kinase (PK) is a key enzyme in the glycolysis process. This review focuses on the glycolysis function of PKM2, although PKM1 and PKM2 both play significant roles in the process after cardiac injury. PKM2 exists in both low-activity dimer and high-activity tetramer forms. PKM2 dimers promote aerobic glycolysis but have low catalytic activity, leading to the accumulation of glycolytic intermediates. These intermediates enter the pentose phosphate pathway to promote cardiomyocyte proliferation and heart regeneration. Additionally, they activate adenosine triphosphate (ATP)-sensitive K + (K ATP ) channels, protecting the heart against ischemic damage. PKM2 tetramers function similar to PKM1 in glycolysis, promoting pyruvate oxidation and subsequently ATP generation to protect the heart from ischemic damage. They also activate KDM5 through the accumulation of αKG, thereby promoting cardiomyocyte proliferation and cardiac regeneration. Apart from glycolysis, PKM2 interacts with transcription factors like Jmjd4, RAC1, β-catenin, and hypoxia-inducible factor (HIF)-1α, playing various roles in homeostasis maintenance, remodeling, survival regulation, and neovascularization promotion. However, PKM2 has also been implicated in promoting cardiac fibrosis through mechanisms like sirtuin (SIRT) 3 deletion, TG2 expression enhancement, and activation of transforming growth factor-β1 (TGF-β1)/Smad2/3 and Jak2/Stat3 signals. Overall, PKM2 shows promising potential as a therapeutic target for promoting cardiomyocyte proliferation and cardiac regeneration and addressing cardiac fibrosis after injury.

Research progresses on mitochondrial-targeted biomaterials for bone defect repair

In recent years, the regulation of the cell microenvironment has opened up new avenues for bone defect repair. Researchers have developed novel biomaterials to influence the behavior of osteoblasts and immune cells by regulating the microenvironment, aiming to achieve efficient bone repair. Mitochondria, as crucial organelles involved in energy conversion, biosynthesis and signal transduction, play a vital role in maintaining bone integrity. Dysfunction of mitochondria can have detrimental effects on the transformation of the immune microenvironment and the differentiation of stem cells, thereby hindering bone tissue regeneration. Consequently, targeted therapy strategies focusing on mitochondria have emerged. This approach offers a wide range of applications and reliable therapeutic effects, thereby providing a new treatment option for complex and refractory bone defect diseases. In recent studies, more biomaterials have been used to restore mitochondrial function and promote positive cell differentiation. The main directions are mitochondrial energy metabolism, mitochondrial biogenesis and mitochondrial quality control. In this review, we investigated the biomaterials used for mitochondria-targeted treatment of bone defect repair in recent years from the perspective of progress and strategies. We also summarized the micro-molecular mechanisms affected by them. Through discussions on energy metabolism, oxidative stress regulation and autophagy regulation, we emphasized the opportunities and challenges faced by mitochondria-targeted biomaterials, providing vital clues for developing a new generation of bone repair materials.

Protein Arginine Methyltransferase CARM1 in Human Breast Cancer

Coactivator-associated arginine methyltransferase 1 (CARM1) is a protein arginine methyltransferase that deposits asymmetrical dimethylation marks on both histone and nonhistone substrates. The regulatory role of CARM1 in transcription was first identified in estrogen receptor positive (ER+) breast cancer. Since then, the mechanism of CARM1 in activating ER-target genes has been further interrogated. CARM1 is expressed at the highest level in ER negative (ER-) breast cancer and higher expression correlates with poor prognosis, suggesting an oncogenic role of CARM1. Indeed, in ER- breast cancer, CARM1 can promote proliferation and metastasis at least partly through methylation of proteins and activation of oncogenes. In this review, we summarize the mechanisms of transcriptional activation by CARM1 in breast cancer. The methyltransferase activity of CARM1 is important for many of its functions; here, we also highlight the nonenzymatic roles of CARM1. We also cover the biological processes regulated by CARM1 that are often deregulated in cancer and the ways to harness CARM1 in cancer treatment.

ROS-mediated cytoplasmic localization of CARM1 induces mitochondrial fission through DRP1 methylation

The dynamic regulation of mitochondria through fission and fusion is essential for maintaining cellular homeostasis. In this study, we discovered a role of coactivator-associated arginine methyltransferase 1 (CARM1) in mitochondrial dynamics. CARM1 methylates specific residues (R403 and R634) on dynamin-related protein 1 (DRP1). Methylated DRP1 interacts with mitochondrial fission factor (Mff) and forms self-assembly on the outer mitochondrial membrane, thereby triggering fission, reducing oxygen consumption, and increasing reactive oxygen species (ROS) production. This sets in motion a feedback loop that facilitates the translocation of CARM1 from the nucleus to the cytoplasm, enhancing DRP1 methylation and ROS production through mitochondrial fragmentation. Consequently, ROS reinforces the CARM1-DRP1-ROS axis, resulting in cellular senescence. Depletion of CARM1 or DRP1 impedes cellular senescence by reducing ROS accumulation. The uncovering of the above-described mechanism fills a missing piece in the vicious cycle of ROS-induced senescence and contributes to a better understanding of the aging process.

Lactic acid: a narrative review of a promoter of the liver cancer microenvironment

Background and Objective

Lactic acid is a metabolite of glycolysis produced in the body, and its production is thought to be a mechanism by which cancer cells evade immune surveillance. Immune evasion and metabolic changes are well established as basic hallmarks of cancer. Although lactate has long been considered a waste product, it is now generally recognized to be a versatile small-molecule chemical that plays an important part in the tumor microenvironment (TME), with increased lactate production linked to the development of human malignancies. Metabolism in liver cancer is redirected toward glycolysis, which enhances the production of metabolic compounds used by tumor cells to produce proteins, lipids, and nucleotides, enabling them to maintain high proliferation rates and to establish the TME. Dysregulation of metabolic activity in liver cancer may impair antitumor responses owing to the immunosuppressive activity of the lactate produced by anaerobic glycolytic rates in tumor cells. This review primarily explores the link connection between lactic acid and the TME; evaluates the role of lactic acid in the occurrence, metastasis, prognosis, and treatment of liver cancer. Additionally, it investigates the associated pathways as potential targets for liver cancer treatment.

Methods

Literature searches were conducted in PubMed, Web of Science, and Google Scholar, with the publication date of the most recent article included being January 2024. After eliminating duplicate articles and less relevant articles through titles and abstracts, we selected 113 articles for this review. We categorized references into two categories. One is to classify the content into lactate-related, liver cancer-related and tumor metabolism-related. The other is to classify the article types, which are divided into reviews, research articles and clinical trials. Additionally, we consulted the reference lists of the relevant articles to ensure coverage was comprehensive and unbiased.

Key Content and Findings

The connection between lactic acid and the TME has recently become an area of intense research interest, and many related articles have been published in this field. The main finding of this review is to summarize the proven link between lactate and the TME and its possible impact on the TME of liver cancer. And analyzed the potential of lactate in liver cancer treatment and prognosis prediction.

Conclusions

Lactate may be key to developing novel approaches in the future treatment of liver cancer. Related research on the combination of classic therapies and molecular targeted drugs may provide innovative medicines that more selectively regulate immune cell activity.

The multifaceted roles of small extracellular vesicles in metabolic reprogramming in the tumor microenvironments

The link between metabolism and tumor progression has been extensively researched for a long time. With the increasing number of studies uncovering the multiple functions of metabolic reprogramming in tumor microenvironments, the regulatory network seems to become even more intricate at the same time. Small extracellular vesicles (sEV), as crucial mediators facilitating intercellular communications, exhibit significant involvement in regulating metabolic reprogramming within the complicated network of tumor microenvironments. sEV derived from tumor cells and those released by other cell populations such as tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) can mutually influence each other, giving rise to diverse complex feedback loops. This review includes multiple studies conducted in recent years to summarize the functions of sEV in altering metabolism in various cell types within tumor microenvironments. Additionally, it aims to highlight potential therapeutic targets based on the commonly observed mechanisms identified in different studies.

A CARM1 Inhibitor Potently Suppresses Breast Cancer Both In Vitro and In Vivo

CARM1, belonging to the protein arginine methyltransferase (PRMT) family, is intricately associated with the progression of cancer and is viewed as a promising target for both cancer diagnosis and therapy. However, the number of specific and potent CARM1 inhibitors is limited. We herein discovered a CARM1 inhibitor, iCARM1, that showed better specificity and activity toward CARM1 compared to the known CARM1 inhibitors, EZM2302 and TP-064. Similar to CARM1 knockdown, iCARM1 suppressed the expression of oncogenic estrogen/ERα-target genes, whereas activated type I interferon (IFN) and IFN-induced genes (ISGs) in breast cancer cells. Consequently, iCARM1 potently suppressed breast cancer cell growth both in vitro and in vivo. The combination of iCARM1 with either endocrine therapy drugs or etoposide demonstrated synergistic effects in inhibiting the growth of breast tumors. In summary, targeting CARM1 by iCARM1 effectively suppresses breast tumor growth, offering a promising therapeutic approach for managing breast cancers in clinical settings.

ESM1 enhances fatty acid synthesis and vascular mimicry in ovarian cancer by utilizing the PKM2-dependent warburg effect within the hypoxic tumor microenvironment

BACKGROUND

The hypoxic tumor microenvironment is a key factor that promotes metabolic reprogramming and vascular mimicry (VM) in ovarian cancer (OC) patients. ESM1, a secreted protein, plays an important role in promoting proliferation and angiogenesis in OC. However, the role of ESM1 in metabolic reprogramming and VM in the hypoxic microenvironment in OC patients has not been determined.

METHODS

Liquid chromatography coupled with tandem MS was used to analyze CAOV3 and OV90 cells. Interactions between ESM1, PKM2, UBA2, and SUMO1 were detected by GST pull-down, Co-IP, and molecular docking. The effects of the ESM1-PKM2 axis on cell glucose metabolism were analyzed based on an ECAR experiment. The biological effects of the signaling axis on OC cells were detected by tubule formation, transwell assay, RT‒PCR, Western blot, immunofluorescence, and in vivo xenograft tumor experiments.

RESULTS

Our findings demonstrated that hypoxia induces the upregulation of ESM1 expression through the transcription of HIF-1α. ESM1 serves as a crucial mediator of the interaction between PKM2 and UBA2, facilitating the SUMOylation of PKM2 and the subsequent formation of PKM2 dimers. This process promotes the Warburg effect and facilitates the nuclear translocation of PKM2, ultimately leading to the phosphorylation of STAT3. These molecular events contribute to the promotion of ovarian cancer glycolysis and vasculogenic mimicry. Furthermore, our study revealed that Shikonin effectively inhibits the molecular interaction between ESM1 and PKM2, consequently preventing the formation of PKM2 dimers and thereby inhibiting ovarian cancer glycolysis, fatty acid synthesis and vasculogenic mimicry.

CONCLUSION

Our findings demonstrated that hypoxia increases ESM1 expression through the transcriptional regulation of HIF-1α to induce dimerization via PKM2 SUMOylation, which promotes the OC Warburg effect and VM.

Research Progress on CARM1 and its Relationship with Colorectal Cancer

Coactivator-associated arginine methyltransferase 1 (CARM1) is significant as a key member of the PRMT family, crucial for regulating arginine methylation, and its association with colorectal cancer underscores its potential as a therapeutic target. Consequently, CARM1 inhibitors have emerged as potential therapeutic agents in cancer treatment and valuable chemical tools for cancer research. Despite steady progress in CARM1 inhibitor research, challenges persist in discovering effective, isoform-selective, cell-permeable, and in vivo-active CARM1 inhibitors for colorectal cancer. This review summarizes the research progress on CARM1 and its relationship with colorectal cancer, aiming to provide a theoretical basis for the radiotherapy of colorectal cancer.

NEAT1 repression by MED12 creates chemosensitivity in p53 wild-type breast cancer cells

Breast cancer is often treated with chemotherapy. However, the development of chemoresistance results in treatment failure. Long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been shown to contribute to chemoresistance in breast cancer cells. In studying the transcriptional regulation of NEAT1 using multi-omics approaches, we showed that NEAT1 is up-regulated by 5-fluorouracil in breast cancer cells with wild-type cellular tumor antigen p53 but not in mutant-p53-expressing breast cancer cells. The regulation of NEAT1 involves mediator complex subunit 12 (MED12)-mediated repression of histone acetylation marks at the promoter region of NEAT1. Knockdown of MED12 but not coactivator-associated arginine methyltransferase 1 (CARM1) induced histone acetylation at the NEAT1 promoter, leading to elevated NEAT1 mRNAs, resulting in a chemoresistant phenotype. The MED12-dependent regulation of NEAT1 differs between wild-type and mutant p53-expressing cells. MED12 depletion led to increased expression of NEAT1 in a wild-type p53 cell line, but decreased expression in a mutant p53 cell line. Chemoresistance caused by MED12 depletion can be partially rescued by NEAT1 knockdown in p53 wild-type cells. Collectively, our study reveals a novel mechanism of chemoresistance dependent on MED12 transcriptional regulation of NEAT1 in p53 wild-type breast cancer cells.

Exploring the diverse role of pyruvate kinase M2 in cancer: Navigating beyond glycolysis and the Warburg effect

Pyruvate Kinase M2, a key enzyme in glycolysis, has garnered significant attention in cancer research due to its pivotal role in the metabolic reprogramming of cancer cells. Originally identified for its association with the Warburg effect, PKM2 has emerged as a multifaceted player in cancer biology. The functioning of PKM2 is intricately regulated at multiple levels, including controlling the gene expression via various transcription factors and non-coding RNAs, as well as adding post-translational modifications that confer distinct functions to the protein. Here, we explore the diverse functions of PKM2, encompassing newly emerging roles in non-glycolytic metabolic regulation, immunomodulation, inflammation, DNA repair and mRNA processing, beyond its canonical role in glycolysis. The ever-expanding list of its functions has recently grown to include roles in subcellular compartments such as the mitochondria and extracellular milieu as well, all of which make PKM2 an attractive drug target in the pursuit of therapeutics for cancer.

The role of PKM2 in cancer progression and its structural and biological basis

Pyruvate kinase M2 (PKM2), a subtype of pyruvate kinase (PK), has been shown to play an important role in the development of cancer. It regulates the last step of glycolytic pathway. PKM2 has both pyruvate kinase and protein kinase activity, and the conversion of these two functions of PKM2 depends on the mutual change of dimer and tetramer. The dimerization of PKM2 can promote the proliferation and growth of tumor cells, so inhibiting the dimerization of PKM2 is essential to curing cancer. The aggregation of PKM2 is regulated by both endogenous and exogenous cofactors as well as post-translational modification (PTM). Although there are many studies on the different aggregation of PKM2 in the process of tumor development, there are few summaries in recent years. In this review, we first introduce the role of PKM2 in various biological processes of tumor growth. Then, we summarize the aggregation regulation mechanism of PKM2 by various endogenous cofactors such as Fructose-1, 6-diphosphate (FBP), various amino acids, and post-translational modification (PTMs). Finally, the related inhibitors and agonists of PKM2 are summarized to provide reference for regulating PKM2 aggregation in the treatment of cancer in the future.

PRMT6 deficiency or inhibition alleviates neuropathic pain by decreasing glycolysis and inflammation in microglia

Microglia induced chronic inflammation is the critical pathology of Neuropathic pain (NP). Metabolic reprogramming of macrophage has been intensively reported in various chronic inflammation diseases. However, the metabolic reprogramming of microglia in chronic pain remains to be elusive. Here, we reported that immuno-metabolic markers (HIF-1α, PKM2, GLUT1 and lactate) were related with increased expression of PRMT6 in the ipsilateral spinal cord dorsal horn of the chronic construction injury (CCI) mice. PRMT6 deficiency or prophylactic and therapeutic intrathecal administration of PRMT6 inhibitor (EPZ020411) ameliorated CCI-induced NP, inflammation and glycolysis in the ipsilateral spinal cord dorsal horn. PRMT6 knockout or knockdown inhibited LPS-induced inflammation, proliferation and glycolysis in microglia cells. While PRMT6 overexpression exacerbated LPS-induced inflammation, proliferation and glycolysis in BV2 cells. Recent research revealed that PRMT6 could interact with and methylate HIF-1α, which increased HIF-1α protein stability. In sum, increased expression of PRMT6 exacerbates NP progress by increasing glycolysis and neuroinflammation through interacting with and stabilizing HIF-1α in a methyltransferase manner, which outlines novel pathological mechanism and drug target for NP.

Pharmacoinformatics approach for the screening of Kovidra (Bauhinia variegata) phytoconstituents against tumor suppressor protein in triple negative breast cancer

Globally, 2.3 million women were diagnosed with breast cancer, with 6,85000 mortalities in year 2021; making it the world's most prevalent cancer. This growing global burden necessitates a new treatment option, and plant-based medicines offers a promising alternative to conventional cancer treatment. In this work, screening of phytoconstituents of an indigenous therapeutic plant, Bauhinia variegata carried out for potential regulator of tumor suppressor protein p53. Here, an in-silico analysis was employed to develop more effective, pharmaceutically potent small drug-like compounds that target tumor suppressor protein p53. The methanol and aqueous powdered extracts of Bauhinia variegata were prepared and phytochemically evaluated along with antioxidant property evaluation. The LC50 of methanol (325.33 µg/ml) and aqueous extract (361.15 µg/ml) showed their cytotoxic characteristics. Further, GCMS analysis of both the extracts reveals total 57 secondary metabolites. Among these, four lead compounds; compound 1, compound 2, compound 3 and compound 4 were found to have the highest binding ability (-8.15 to -5.40 kcal/mol) with p53. MD simulation and binding free energy validates these findings with highest binding free energy (-67.09 ± 4.87 kcal/mol) towards p53 by the lead phytocompound 2. Selected compounds exhibit excellent pharmacokinetic features and drug-like characteristics. The acute toxicity (LD50) values of the lead phytocompounds ranges from 670 mg/kg to 3100 mg/kg, with toxicity classes of IV and V. As a result, these druggable phytochemicals could serve as potential lead applicants for triple negative breast cancer treatment. However, more in vitro and in vivo research is planned to produce future breast cancer medicine. HIGHLIGHTSScreening of phytoconstituents of an indigenous therapeutic plant, Bauhinia variegata, for potential regulator of tumor suppressor protein p53.The LC50 of methanol (325.33µg/ml) and aqueous extract (361.15µg/ml) showed their cytotoxic characteristics.GCMS analysis of both the extracts reveals total 57 secondary metabolites. Among these, four lead compounds were found to have the highest binding affinity (-8.153 to -5.401 kcal/mol) with tumor suppressor protein p53.MD simulation along with the Prime MM/GBSA binding free energy validates this discovery with highest binding free energy (-67.09 ± 4.87 kcal/mol) towards p53 by the lead compound 2.The acute toxicity (LD50) values of the lead phytocompounds ranges from 670 mg/kg to 3100 mg/kg, with toxicity classes of IV and V.As a result, these druggable phytochemicals could serve as potential lead applicants for triple negative breast cancer treatment.Communicated by Ramaswamy H. Sarma.

Tyrosine phosphorylation of CARM1 promotes its enzymatic activity and alters its target specificity

An important epigenetic component of tyrosine kinase signaling is the phosphorylation of histones, and epigenetic readers, writers, and erasers. Phosphorylation of protein arginine methyltransferases (PRMTs), have been shown to enhance and impair their enzymatic activity. In this study, we show that the hyperactivation of Janus kinase 2 (JAK2) by the V617F mutation phosphorylates tyrosine residues (Y149 and Y334) in coactivator-associated arginine methyltransferase 1 (CARM1), an important target in hematologic malignancies, increasing its methyltransferase activity and altering its target specificity. While non-phosphorylatable CARM1 methylates some established substrates (e.g. BAF155 and PABP1), only phospho-CARM1 methylates the RUNX1 transcription factor, on R223 and R319. Furthermore, cells expressing non-phosphorylatable CARM1 have impaired cell-cycle progression and increased apoptosis, compared to cells expressing phosphorylatable, wild-type CARM1, with reduced expression of genes associated with G2/M cell cycle progression and anti-apoptosis. The presence of the JAK2-V617F mutant kinase renders acute myeloid leukemia (AML) cells less sensitive to CARM1 inhibition, and we show that the dual targeting of JAK2 and CARM1 is more effective than monotherapy in AML cells expressing phospho-CARM1. Thus, the phosphorylation of CARM1 by hyperactivated JAK2 regulates its methyltransferase activity, helps select its substrates, and is required for the maximal proliferation of malignant myeloid cells.

Pyruvate kinase M2 sustains cardiac mitochondrial integrity in septic cardiomyopathy by regulating PHB2-dependent mitochondrial biogenesis

Previous studies have highlighted the protective effects of pyruvate kinase M2 (PKM2) overexpression in septic cardiomyopathy. In our study, we utilized cardiomyocyte-specific PKM2 knockout mice to further investigate the role of PKM2 in attenuating LPS-induced myocardial dysfunction, focusing on mitochondrial biogenesis and prohibitin 2 (PHB2). Our findings confirmed that the deletion of PKM2 in cardiomyocytes significantly exacerbated LPS-induced myocardial dysfunction, as evidenced by impaired contractile function and relaxation. Additionally, the deletion of PKM2 intensified LPS-induced myocardial inflammation. At the molecular level, LPS triggered mitochondrial dysfunction, characterized by reduced ATP production, compromised mitochondrial respiratory complex I/III activities, and increased ROS production. Intriguingly, the absence of PKM2 further worsened LPS-induced mitochondrial damage. Our molecular investigations revealed that LPS disrupted mitochondrial biogenesis in cardiomyocytes, a disruption that was exacerbated by the absence of PKM2. Given that PHB2 is known as a downstream effector of PKM2, we employed PHB2 adenovirus to restore PHB2 levels. The overexpression of PHB2 normalized mitochondrial biogenesis, restored mitochondrial integrity, and promoted mitochondrial function. Overall, our results underscore the critical role of PKM2 in regulating the progression of septic cardiomyopathy. PKM2 deficiency impeded mitochondrial biogenesis, leading to compromised mitochondrial integrity, increased myocardial inflammation, and impaired cardiac function. The overexpression of PHB2 mitigated the deleterious effects of PKM2 deletion. This discovery offers a novel insight into the molecular mechanisms underlying septic cardiomyopathy and suggests potential therapeutic targets for intervention.

PRMT1 Sustains De Novo Fatty Acid Synthesis by Methylating PHGDH to Drive Chemoresistance in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) chemoresistance hampers the ability to effectively treat patients. Identification of mechanisms driving chemoresistance can lead to strategies to improve treatment. Here, we revealed that protein arginine methyltransferase-1 (PRMT1) simultaneously methylates D-3-phosphoglycerate dehydrogenase (PHGDH), a critical enzyme in serine synthesis, and the glycolytic enzymes PFKFB3 and PKM2 in TNBC cells. 13C metabolic flux analyses showed that PRMT1-dependent methylation of these three enzymes diverts glucose toward intermediates in the serine-synthesizing and serine/glycine cleavage pathways, thereby accelerating the production of methyl donors in TNBC cells. Mechanistically, PRMT1-dependent methylation of PHGDH at R54 or R20 activated its enzymatic activity by stabilizing 3-phosphoglycerate binding and suppressing polyubiquitination. PRMT1-mediated PHGDH methylation drove chemoresistance independently of glutathione synthesis. Rather, activation of the serine synthesis pathway supplied α-ketoglutarate and citrate to increase palmitate levels through activation of fatty acid synthase (FASN). Increased palmitate induced protein S-palmitoylation of PHGDH and FASN to further enhance fatty acid synthesis in a PRMT1-dependent manner. Loss of PRMT1 or pharmacologic inhibition of FASN or protein S-palmitoyltransferase reversed chemoresistance in TNBC. Furthermore, IHC coupled with imaging MS in clinical TNBC specimens substantiated that PRMT1-mediated methylation of PHGDH, PFKFB3, and PKM2 correlates with chemoresistance and that metabolites required for methylation and fatty acid synthesis are enriched in TNBC. Together, these results suggest that enhanced de novo fatty acid synthesis mediated by coordinated protein arginine methylation and protein S-palmitoylation is a therapeutic target for overcoming chemoresistance in TNBC.

SIGNIFICANCE

PRMT1 promotes chemoresistance in TNBC by methylating metabolic enzymes PFKFB3, PKM2, and PHGDH to augment de novo fatty acid synthesis, indicating that targeting this axis is a potential treatment strategy.

Exploring Epigenetic and Genetic Modulation in Animal Responses to Thermal Stress

There is increasing evidence indicating that global temperatures are rising significantly, a phenomenon commonly referred to as 'global warming', which in turn is believed to be causing drastic changes to the global climate. Global warming (GW) directly impacts animal health, reproduction, production, and welfare, presenting several challenges to livestock enterprises. Thermal stress (TS) is one of the key consequences of GW, and all animal species, including livestock, have diverse physiological, epigenetic and genetic mechanisms to respond to TS. As a result, TS can significantly affect an animals' health, immune responsiveness, metabolic pathways etc. which can also influence the productivity, performance, and welfare of animals. Moreover, prolonged exposure to TS can lead to transgenerational and intergenerational changes that are mediated by epigenetic changes. For example, in several animal species, the effects of TS are encoded epigenetically during the animals' growth or productive stage, and these epigenetic changes can be transmitted intergenerationally. Such epigenetic changes can affect animal productivity by changing the phenotype so that it aligns with its ancestors' environment, irrespective of its immediate environment. Furthermore, epigenetic and genetic changes can also help protect cells from the adverse effects of TS by modulating the transcriptional status of heat-responsive genes in animals. This review focuses on the genetic and epigenetic modulation and regulation that occurs in TS conditions via HSPs, histone alterations and DNA methylation.

Targeting the Warburg effect: A revisited perspective from molecular mechanisms to traditional and innovative therapeutic strategies in cancer

Cancer reprogramming is an important facilitator of cancer development and survival, with tumor cells exhibiting a preference for aerobic glycolysis beyond oxidative phosphorylation, even under sufficient oxygen supply condition. This metabolic alteration, known as the Warburg effect, serves as a significant indicator of malignant tumor transformation. The Warburg effect primarily impacts cancer occurrence by influencing the aerobic glycolysis pathway in cancer cells. Key enzymes involved in this process include glucose transporters (GLUTs), HKs, PFKs, LDHs, and PKM2. Moreover, the expression of transcriptional regulatory factors and proteins, such as FOXM1, p53, NF-κB, HIF1α, and c-Myc, can also influence cancer progression. Furthermore, lncRNAs, miRNAs, and circular RNAs play a vital role in directly regulating the Warburg effect. Additionally, gene mutations, tumor microenvironment remodeling, and immune system interactions are closely associated with the Warburg effect. Notably, the development of drugs targeting the Warburg effect has exhibited promising potential in tumor treatment. This comprehensive review presents novel directions and approaches for the early diagnosis and treatment of cancer patients by conducting in-depth research and summarizing the bright prospects of targeting the Warburg effect in cancer.

CIP2A induces PKM2 tetramer formation and oxidative phosphorylation in non-small cell lung cancer

Tumor cells are usually considered defective in mitochondrial respiration, but human non-small cell lung cancer (NSCLC) tumor tissues are shown to have enhanced glucose oxidation relative to adjacent benign lung. Here, we reported that oncoprotein cancerous inhibitor of protein phosphatase 2A (CIP2A) inhibited glycolysis and promoted oxidative metabolism in NSCLC cells. CIP2A bound to pyruvate kinase M2 (PKM2) and induced the formation of PKM2 tetramer, with serine 287 as a novel phosphorylation site essential for PKM2 dimer-tetramer switching. CIP2A redirected PKM2 to mitochondrion, leading to upregulation of Bcl2 via phosphorylating Bcl2 at threonine 69. Clinically, CIP2A level in tumor tissues was positively correlated with the level of phosphorylated PKM2 S287. CIP2A-targeting compounds synergized with glycolysis inhibitor in suppressing cell proliferation in vitro and in vivo. These results indicated that CIP2A facilitates oxidative phosphorylation by promoting tetrameric PKM2 formation, and targeting CIP2A and glycolysis exhibits therapeutic potentials in NSCLC.

A diagnostic model based on DNA methylation haplotype block characteristics for identifying papillary thyroid carcinoma from thyroid adenoma

Papillary thyroid carcinoma (PTC) is the most prevalent form of thyroid cancer. Methylation of some genes plays a crucial role in the tendency to malignancy as well as poor prognosis of thyroid cancer, suggesting that methylation features can serve as complementary markers for molecular diagnosis. In this study, we aimed to develop and validate a diagnostic model for PTC based on DNA methylation markers. A total of 142 thyroid nodule tissue samples containing 84 cases of PTC and 58 cases of thyroid adenoma (TA) were collected for reduced representation bisulfite sequencing (RRBS) and subsequent analysis. The diagnostic model was constructed by the logistic regression (LR) method followed by 5-cross validation and based on 94 tissue methylation haplotype block (MHB) markers. The model achieved an area under the receiver operating characteristic curve (AUROC) of 0.974 (95% CI, 0.964-0.981) on 108 training samples and 0.917 (95% CI, 0.864-0.973) on 27 independent testing samples. The diagnostic model scores showed significantly high in males (P = 0.0016), age ≤ 45 years (P = 0.026), high body mass index (BMI) (P = 0.040), lymph node metastasis (P = 0.00052) and larger nodules (P = 0.0017) in the PTC group, and the risk score of this diagnostic model showed significantly high in recurrent PTC group (P = 0.0005). These results suggest that the diagnostic model can be expected to be a powerful tool for PTC diagnosis and there are more potential clinical applications of methylation markers to be excavated.

PKM2 is a Novel Osteoporosis-Associated Protein in Chinese

                       Purpose:Osteoporosis is characterized by low bone mineral density (BMD) and high risk of osteoporotic fracture (OF). Peripheral blood monocytes (PBM) can differentiate into osteoclasts to resorb bone. This study was to identify PBM-expressed proteins significant for osteoporosis in Chinese Han elderly population (>65 years), and focused on two phenotypes of osteoporosis: low BMD and OF.

METHODS

Label-free quantitative proteomics was employed to profile PBM proteome and to identify differentially expressed proteins (DEPs) between OF (N=27) vs. non-fractured (NF, N=24) subjects and between low BMD (N=12) vs. high BMD (N=12) subjects in women. Western blotting (WB) was conducted to validate differential expression, and ELISA to evaluate translational value for secretory protein of interest.

RESULTS

We discovered 59 DEPs with fold change (FC)>1.3 (P<1×10-5), and validated the significant up-regulation of pyruvate kinase isozyme 2 (PKM2) with osteoporosis (P<0.001). PKM2 protein upregulation with OF was replicated with PBM in men (P=0.04). Plasma PKM2 protein level was significantly elevated with OF in an independent sample (N=100, FC=1.68, P=0.01). Pursuant functional assays showed that extracellular PKM2 protein supplement not only promoted monocyte trans-endothelial migration, growth, and osteoclast differentiation (marker gene expression), but also inhibited osteoblast growth, differentiation (ALP gene expression), and activity.

CONCLUSION

The above findings suggest that PKM2 protein is a novel osteoporosis-associated functional protein in Chinese Han elderly population. It may serve as a risk biomarker and drug target for osteoporosis.

Transcriptomics analysis reveals distinct mechanism of breast cancer stem cells regulation in mammospheres from MCF-7 and T47D cells

Luminal A breast cancer, constituting 70 % of breast cancer cases, presents a challenge due to the development of resistance and recurrence caused by breast cancer stem cells (BCSC). Luminal breast tumors are characterized by TP53 expression, a tumor suppressor gene involved in maintaining stem cell attributes in cancer. Although a previous study successfully developed mammospheres (MS) from MCF-7 (with wild-type TP53) and T47D (with mutant TP53) luminal breast cancer cells for BCSC enrichment, their transcriptomic profiles remain unclear. We aimed to elucidate the transcriptomic disparities between MS of MCF-7 and T47D cells using bioinformatics analyses of differentially expressed genes (DEGs), including the KEGG pathway, Gene Ontology (GO), drug-gene association, disease-gene association, Gene Set Enrichment Analysis (GSEA), DNA methylation analysis, correlation analysis of DEGs with immune cell infiltration, and association analysis of genes and small-molecule compounds via the Connectivity Map (CMap). Upregulated DEGs were enriched in metabolism-related KEGG pathways, whereas downregulated DEGs were enriched in the MAPK signaling pathway. Drug-gene association analysis revealed that both upregulated and downregulated DEGs were associated with fostamatinib. The KEGG pathway GSEA results indicated that the DEGs were enriched for oxidative phosphorylation, whereas the downregulated DEGs were negatively enriched for the p53 signaling pathway. Examination of DNA methylation revealed a noticeable disparity in the expression patterns of the PKM2, ERO1L, SLC6A6, EPAS1, APLP2, RPL10L, and NEDD4 genes when comparing cohorts with low- and high-risk breast cancer. Furthermore, a significant positive correlation was identified between SLC6A6 expression and macrophage presence, as well as MSN, and AKR1B1 expression and neutrophil and dentritic cell infiltration. CMap analysis unveiled SA-83851 as a potential candidate to counteract the effects of DEGs, specifically in cells harbouring mutant TP53. Further research, including in vitro and in vivo validations, is warranted to develop drugs targeting BCSCs.

Guanosine diphosphate-mannose suppresses homologous recombination repair and potentiates antitumor immunity in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with poor prognosis. TNBCs with high homologous recombination deficiency (HRD) scores benefit from DNA-damaging agents, including platinum drugs and poly(ADP-ribose) polymerase (PARP) inhibitors, whereas those with low HRD scores still lack therapeutic options. Therefore, we sought to exploit metabolic alterations to induce HRD and sensitize DNA-damaging agents in TNBCs with low HRD scores. We systematically analyzed TNBC metabolomics and identified a metabolite, guanosine diphosphate (GDP)-mannose (GDP-M), that impeded homologous recombination repair (HRR). Mechanistically, the low expression of the upstream enzyme GDP-mannose-pyrophosphorylase-A (GMPPA) led to the endogenous up-regulation of GDP-M in TNBC. The accumulation of GDP-M in tumor cells further reduced the interaction between breast cancer susceptibility gene 2 (BRCA2) and ubiquitin-specific peptidase 21 (USP21), which promoted the ubiquitin-mediated degradation of BRCA2 to inhibit HRR. Therapeutically, we illustrated that the supplementation of GDP-M sensitized DNA-damaging agents to impair tumor growth in both in vitro (cancer cell line and patient-derived organoid) and in vivo (xenograft in immunodeficient mouse) models. Moreover, the combination of GDP-M with DNA-damaging agents activated STING-dependent antitumor immunity in immunocompetent syngeneic mouse models. Therefore, GDP-M supplementation combined with PARP inhibition augmented the efficacy of anti-PD-1 antibodies. Together, these findings suggest that GDP-M is a crucial HRD-related metabolite and propose a promising therapeutic strategy for TNBCs with low HRD scores using the combination of GDP-M, PARP inhibitors, and anti-PD-1 immunotherapy.

GRK2 inhibits Flt-1+ macrophage infiltration and its proangiogenic properties in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease with a complex etiology. Monocyte-derived macrophages (MDMs) infiltration are associated with RA severity. We have reported the deletion of G-protein-coupled receptor kinase 2 (GRK2) reprograms macrophages toward an anti-inflammatory phenotype by recovering G-protein-coupled receptor signaling. However, as more GRK2-interacting proteins were discovered, the GRK2 interactome mechanisms in RA have been understudied. Thus, in the collagen-induced arthritis mouse model, we performed genetic GRK2 deletion using GRK2f/fLyz2-Cre+/- mice. Synovial inflammation and M1 polarization were improved in GRK2f/fLyz2-Cre+/- mice. Supporting experiments with RNA-seq and dual-luciferase reporter assays identified peroxisome proliferator-activated receptor γ (PPARγ) as a new GRK2-interacting protein. We further confirmed that fms-related tyrosine kinase 1 (Flt-1), which promoted macrophage migration to induce angiogenesis, was inhibited by GRK2-PPARγ signaling. Mechanistically, excess GRK2 membrane recruitment in CIA MDMs reduced the activation of PPARγ ligand-binding domain and enhanced Flt-1 transcription. Furthermore, the treatment of mice with GRK2 activity inhibitor resulted in significantly diminished CIA pathology, Flt-1+ macrophages induced-synovial inflammation, and angiogenesis. Altogether, we anticipate to facilitate the elucidation of previously unappreciated details of GRK2-specific intracellular signaling. Targeting GRK2 activity is a viable strategy to inhibit MDMs infiltration, affording a distinct way to control joint inflammation and angiogenesis of RA.

Tiam1 methylation by NSD2 promotes Rac1 signaling activation and colon cancer metastasis

Metastasis is a major cause of cancer therapy failure and mortality. However, targeting metastatic seeding and colonization remains a significant challenge. In this study, we identified NSD2, a histone methyltransferase responsible for dimethylating histone 3 at lysine 36, as being overexpressed in metastatic tumors. Our findings suggest that NSD2 overexpression enhances tumor metastasis both in vitro and in vivo. Further analysis revealed that NSD2 promotes tumor metastasis by activating Rac1 signaling. Mechanistically, NSD2 combines with and activates Tiam1 (T lymphoma invasion and metastasis 1) and promotes Rac1 signaling by methylating Tiam1 at K724. In vivo and in vitro studies revealed that Tiam1 K724 methylation could be a predictive factor for cancer prognosis and a potential target for metastasis inhibition. Furthermore, we have developed inhibitory peptide which was proved to inhibit tumor metastasis through blocking the interaction between NSD2 and Tiam1. Our results demonstrate that NSD2-methylated Tiam1 promotes Rac1 signaling and cancer metastasis. These results provide insights into the inhibition of tumor metastasis.