Liver cancer has consistently high incidence and mortality rates among malignant tumors. PCSK9, a target for hypercholesterolemia therapy, has recently been identified as an inhibitor of anti-tumor immunity, and targeting PCSK9 effectively inhibits tumor progression. However, small molecule inhibitors are lacking due to its flat protein structure.

PCSK9 transcription inhibitor screening was conducted using a PCSK9 promoter-driven td-Tomato plasmid. Quantitative real-time PCR and immunoblotting were employed to assess the effect of L-methionine on PCSK9 expression in HCC cell lines. Co-culture experiments were performed to evaluate the impact of L-methionine on CD8+ T cell-mediated killing of liver cancer cells. RNA sequencing, CUT&Tag, gene editing, and luciferase reporter assays were utilized to identify the transcription factor regulating PCSK9. Additionally, liver cancer xenograft and spontaneous liver cancer mouse models were used to evaluate the anti-cancer efficacy of L-methionine.

Our study identified L-methionine, an essential amino acid, as a transcriptional inhibitor of PCSK9. The optimal dose of L-methionine to inhibit PCSK9 expression and enhance CD8+ T cell-mediated killing of liver cancer cells in vitro is 50 μM. Furthermore, intraperitoneal injection of 5 mg/kg/day of L-methionine significantly inhibited tumor growth in both liver cancer xenograft and spontaneous liver cancer mouse models. Mechanistically, we identified NR1I2 as a key transcription factor for PCSK9 and their crucial binding site was TGCACCCTGACAC. L-methionine inhibits PCSK9 transcription by downregulating NR1I2.

This work demonstrates that L-methionine promotes CD8+ T cell-mediated killing of hepatocellular carcinoma by inhibiting NR1I2/PCSK9 signaling. Our study introduces a novel and convenient approach to inhibit PCSK9 and provides a theoretical basis for the rational supplementation of L-methionine in liver cancer patients.

The reliance on high levels of methionine by tumor cells provides an attractive target for cancer treatment. However, systemic methionine blockade may raise concerns about potential side effects given the broad and essential functions of methionine in cellular metabolism. Here, a combined drug delivery platform for multilayered constraint of methionine within tumor lesions is developed. Small molecule inhibitors PF9366 and adenosine dialdehyde are encapsulated by tumor cell-targeting nanoparticles (NPs) to achieve a cascaded blockage of intracellular methionine metabolism. These NPs are further co-loaded with the extracellular methionine uptake inhibitor JPH203 into a type of reactive oxygen species-sensitive hydrogel, assembling the multiplex methionine modulating hydrogel (3 M Gel). In murine models of triple-negative breast cancer (TNBC), hepatocellular carcinoma, and colorectal cancer, the in situ formed 3 M Gel exhibits superior efficacy in restricting S-adenosyl methionine generation and histone methylation, stimulating immunogenic cell death in tumor cells, thereby eliciting potent innate and adaptive immune responses to restrain tumor progression. Moreover, remodeling of the tumor microenvironment by 3 M Gel overcomes immune checkpoint blockade resistance in TNBC. This study presents a localized triple regulation strategy and paves a new path for amino acid starvation-based cancer therapy.

Unraveling the intricate mechanisms underlying methionine metabolism reprogramming and its extracellular release during apoptosis requires robust and sensitive quantification of key intermediates in both intracellular and extracellular compartments. Here, we developed a highly sensitive and precise stable isotope-dilution UHPLC-MS/MS method for simultaneous quantification of five critical intermediates in methionine cycle and methionine salvage pathway: l-methionine (Met), S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), l-homocysteine (Hcy), and 5'-methylthioadenosine (5'-MTA). Through optimizing mobile phase additives and implementing an effective dilution strategy, this method minimizes matrix effects. The recovery rates of the five compounds exceeds 71.6 % in cell cytosol and cell medium samples, under a wide concentration range. The validated method presents good precision and linearity, with limits of detection (LODs) ranging from 1.9 fmol/10⁵ cells (SAH) to 555.4 fmol/10⁵ cells (Hcy) in cytosolic fractions, and from 0.7 fmol/10⁵ cells (SAH) to 52.1 fmol/10⁵ cells (Met) in culture media. Application of this validated method to UV-induced apoptosis in human promyelocytic leukemia HL60 cells revealed significant dynamic alterations in both intracellular and extracellular release of methionine pathway intermediates during apoptotic progression. The quantification method provides a robust tool for investigating the regulation and functions of methionine metabolism across basic research and clinical applications.

Lung adenocarcinoma (LUAD) remains a leading cause of cancer mortality due to resistance, metastasis, and recurrence. Unlike conventional cytotoxic therapies, Xingxiao Pills (XXP), a classic traditional Chinese medicine formula, offers a complementary approach to treating LUAD, while its non-cytotoxic anti-cancer mechanisms remain unclear.

To investigate the effect and mechanism of XXP on LUAD progression and stemness via lipid metabolism regulation.

UHPLC-MS/MS was used to analyze the chemical constituents of XXP. The effects of XXP on LUAD cell proliferation, migration, invasion, and stemness were evaluated using CCK-8, Transwell, and tumor sphere assays. A LUAD xenograft model confirmed XXP's anti-tumor effects. Transcriptomics, metabolomics, ELISA, qRT-PCR, and Western blot were used to investigate the underlying mechanisms. Kaplan-Meier (KM) survival analysis and stemness index scores were performed for LUAD patients based on the TCGA dataset. Statistical analyses were performed using Student's t-test, ANOVA, and KM survival analysis (p< 0.05 considered significant).

XXP inhibits LUAD progression in mouse and cell models by targeting lipid metabolism reprogramming. It suppresses FA synthesis, elongation, oxidation, and glycerophospholipid (GPL) metabolism while upregulating arachidonic acid (AA) metabolism. Mechanistic studies revealed that XXP attenuates tumor stemness by inhibiting PLA2G4A (cPLA2), lowering AA release, and disrupting SMO/GLI1/SOX2 signaling, an effect also observed with the cPLA2 inhibitor AACOCF3. KM analysis showed that higher PLA2G4A expression correlated with a worse 5-year prognosis in LUAD (p = 0.0047). The low GPL/high AA group (consistent with XXP's metabolic pattern) had better survival (p = 0.0028) and a lower stemness index (p< 0.0001) than the high GPL/low AA unrelated group.

Xingxiao Pill modulates GPL and AA metabolism and downregulates the PLA2G4A (cPLA2)-AA/SMO/GLI1/SOX2 axis. Through this mechanism, XXP effectively inhibits tumor growth and stemness by targeting lipid metabolism.

Methionine adenosyltransferase 2 A (MAT2A) has been found to mediate osteosarcoma (OS) progression. Therefore, more roles and mechanisms of MAT2A in the development of OS deserve further exploration. The mRNA and protein levels of MAT2A and RNA binding motif protein 15 (RBM15) were tested by quantitative real-time PCR and western blot (WB). Cell proliferation and metastasis were examined using EdU assay and transwell assay. The protein levels of metastasis-related markers and ferroptosis-related marker were measured by WB. Cell ferroptosis was assessed via testing GSH, ROS, and Fe2+ levels. Mice xenograft model was constructed to explore the roles of MAT2A and RBM15 in vivo. RBM15 and MAT2A interaction was assessed by MeRIP assay and dual-luciferase reporter assay. High expression of MAT2A was observed in OS tumor tissues and cells. MAT2A knockdown reduced OS cell proliferation, migration, invasion and enhanced ferroptosis. Silencing of MAT2A inhibited OS tumor growth in vivo. RBM15 was upregulated in OS tumor tissues and cells, which could promote MAT2A expression by N6-methyladenosine (m6A) modification. Downregulation of RBM15 repressed OS cell behaviors and tumorigenesis by decreasing MAT2A expression. In conclusion, MAT2A, regulated by RBM15-mediated m6A modification, accelerated OS malignant progression by increasing cell proliferation, metastasis and decreasing ferroptosis.

Elevated levels of homocysteine (Hcy) are associated with various health outcomes. We aimed to systematically assess the credibility and certainty of evidence of associations of Hcy and Hcy-lowering therapies with various health outcomes. We retrieved observational meta-analyses examining the associations between Hcy and health outcomes, interventional meta-analyses investigating health outcomes related to Hcy-lowering treatments, and Mendelian randomization (MR) studies exploring the causal associations of Hcy with health outcomes to perform an umbrella review. A total of 135 observational meta-analyses, 106 MR studies, and 26 interventional meta-analyses were included. Among observational studies, 10 associations of diseases/outcomes were classified as highly suggestive; only 1 outcome (digestive tract cancer) was supported by convincing evidence (class I; odd ratio = 1.27, 95% confidence interval = 1.16, 1.40; P = 6.79 × 10-7; I2 = 0, 95% prediction interval excluding null, >1000 cases; P > 0.1 for tests of both small-study effects and excess significance bias). In MR studies, 5 outcomes associated with Hcy presented robust evidence (P < 0.01, power >80%). Among 25 outcomes explored by both observational meta-analyses and MR studies, 7 had consistent results, indicating that elevated Hcy is causally associated with an increased risk of these outcomes. The 3 types of studies collectively suggested that the association of stroke with Hcy was supported by observational studies, causally by MR studies, and further validated by intervention meta-analyses showing that Hcy-lowering with folic acid significantly reduced risk of stroke. For dementia and colorectal cancer, Hcy was significantly associated in meta-analyses of observational studies and folic acid decreased disease risks in interventional meta-analyses. The current umbrella review indicates that convincing evidence for a definitive role of Hcy exposure solely exists in the context of digestive tract cancer excluding bias; however, Hcy may not be causal for this disease. All the 3 types of studies collectively support that Hcy is a key causal risk factor, and Hcy-lowering (specifically with folic acid) may serve as an effective intervention for stroke. This trial was registered at PROSPERO as CRD42024541335.

Clear cell renal cell carcinoma (ccRCC) is the most common type of RCC. Even though the targeted drugs for the treatment of ccRCC have a certain therapeutic effect, due to the problem of drug resistance, the search for new targets for targeted therapy of ccRCC remains urgent. GAMT is an enzyme involved in creatine metabolism. However, the precise biological roles and molecular mechanisms of GAMT in ccRCC are not fully understood.

Here, we found that GAMT was upregulated in ccRCC cells and tissues and associated with poor prognosis. Further, GAMT has pro-oncogenic abilities in promoting ccRCC development and progression. Intriguingly, GAMT exerted biological functions independent of its role in catalyzing creatine synthesis. Mechanistically, GAMT overexpression contributes to the development and progression of ccRCC by inhibiting tumor suppressor p53. Finally, we identified fisetin as a novel GAMT inhibitor and validated its role in suppressing ccRCC progression and sensitizing ccRCC cells to targeted drug axitinib via in vivo and in vitro assays.

This study reveals that GAMT has pro-oncogenic abilities in promoting ccRCC development and progression. GAMT exerted its non-enzymatic functions possibly by regulating the expression of p53. Fisetin, the novel GAMT inhibitor identified herein, may serve as a new antitumor drug for ccRCC treatment.

Given the resistance to conventional treatments and limitations of immune checkpoint blockade therapy in hepatocellular carcinoma (HCC), it is imperative to explore novel prognostic models and biomarkers. The dependence of cancer cell on exogenous methionine, known as Hoffman effect, is a hallmark of HCC, with numerous studies reporting a strong correlation between methionine metabolism and tumor development. Betaine-homocysteine S-methyltransferase (BHMT), a critical component of methionine metabolism pathway, has polymorphisms linking to poor prognosis in multiple cancers. Nevertheless, there is little literature regarding the relationship between methionine metabolism and incidence, mortality of HCC, as well as the function of BHMT in HCC progression. In this study, by analyzing multiple datasets, we constructed a methionine metabolism-related prognostic model and thoroughly investigated the influence of BHMT on the prognosis of HCC. Bioinformatics analysis revealed a marked decrease in BHMT expression in HCC, which was linked to adverse clinical outcomes. CIBERSORT results suggest that BHMT promotes infiltration of M1 macrophages. Our results suggest its potential as an ideal prognostic biomarker for anti PD-L1 immunotherapy. In summary, this study innovatively provides first methionine metabolism-related prognostic model and unveils the tumor suppressive function of BHMT in HCC, providing potential mechanism by which BHMT exert its function.

Chemotherapeutic drug resistance remains a major barrier to effective cancer treatment. Drug resistance could be driven in part by adaptive redox remodeling of cancer cells. Paradoxically, drug-resistant malignancies exhibit elevated reactive oxygen species (ROS), as well as amplified antioxidant defenses, which enable cancer cell survival under therapeutic stress. Central to this adaptation is glutathione (GSH), the predominant cellular antioxidant, whose synthesis relies on sulfur-containing amino acids (SAAs) - methionine and cysteine. This review delineates the metabolic interplay between methionine and cysteine in the transsulfuration pathway, highlighting their roles as precursors in GSH biosynthesis. We systematically summarize the key enzymes that drive GSH production and their contributions to resistance against platinum-based drugs and other chemotherapeutics. In addition to GSH synthesis, we summarize the roles of GSH antioxidant systems, including glutathione peroxidases (GPXs), peroxiredoxins (PRDXs), and thioredoxins (TRXs), which are critical in chemotherapeutic drug resistance through ROS scavenging. Recent advances reveal that targeting these enzymes, by pharmacologically inhibiting transsulfuration enzymes or disrupting GSH-dependent antioxidant cascades, can sensitize resistant cancer cells to ROS-mediated therapies. These findings not only clarify the mechanistic links between SAA metabolism and redox adaptation but also provide practical approaches to overcome chemotherapeutic drug resistance. By analyzing metabolic and redox vulnerabilities, this review highlights the therapeutic potential to restore chemosensitivity, offering new options in precision oncology medicine.

The connection between amino acid metabolism and pyroptosis remains elusive. Herein, we screen the effect of individual amino acid on pyroptosis and identify that methionine inhibits GSDME-mediated pyroptosis. Mechanistic analyses unveil that MYO6, a unique actin-based motor protein, bridges the GSDME N-terminus (GSDME-NT) and the endocytic adaptor AP2, mediating endolysosomal degradation of GSDME-NT. This degradation is increased by the methionine-derived metabolite spermidine noncanonically by direct binding to MYO6, which enhances MYO6 selectivity for GSDME-NT. Moreover, combination targeted therapies using dietary or pharmacological inhibition in methionine-to-spermidine metabolism in the tumor promotes pyroptosis and anti-tumor immunity, leading to a stronger tumor-suppressive effect in in vivo models. Clinically, higher levels of tumor spermidine and expression of methionine-to-spermidine metabolism-related gene signature predict poorer survival. Conclusively, our research identifies an unrecognized mechanism of pyroptotic resistance mediated by methionine-spermidine metabolic axis, providing a fresh angle for cancer treatment.

Many cancer cells depend on exogenous methionine for proliferation, whereas non-tumorigenic cells can divide in media supplemented with the metabolic precursor homocysteine. This phenomenon is known as methionine dependence of cancer or methionine addiction. The underlying mechanisms driving this cancer-specific metabolic addiction are poorly understood. Here we find that methionine dependence is associated with severe dysregulation of pre-mRNA splicing.

We used triple-negative breast cancer cells and their methionine-independent derivatives R8 to compare RNA expression profiles in methionine and homocysteine growth media. The data set was also analyzed for alternative splicing.

When tumorigenic cells were cultured in homocysteine medium, cancer cells failed to efficiently methylate the spliceosomal snRNP component SmD1, which resulted in reduced binding to the Survival-of-Motor-Neuron protein SMN leading to aberrant splicing. These effects were specific for cancer cells as neither Sm protein methylation nor splicing fidelity was affected when non-tumorigenic cells were cultured in homocysteine medium. Sm protein methylation is catalyzed by Protein Arginine Methyl Transferase 5 (Prmt5). Reducing methionine concentrations in the culture medium sensitized cancer cells to Prmt5 inhibition supporting a mechanistic link between methionine dependence of cancer and splicing.

Our results link nutritional demands to splicing changes and thereby provide a link between the cancer-specific metabolic phenomenon, described as methionine addiction over 40 years ago, with a defined cellular pathway that contributes to cancer cell proliferation.

Higher and richer nutrient requirements are typical features that distinguish tumor cells from AU: cells, ensuring adequate substrates and energy sources for tumor cell proliferation and migration. Therefore, nutrient deprivation strategies based on targeted technologies can induce impaired cell viability in tumor cells, which are more sensitive than normal cells. In this review, nutrients that are required by tumor cells and related metabolic pathways are introduced, and anti-tumor strategies developed to target nutrient deprivation are described. In addition to tumor cells, the nutritional and metabolic characteristics of other cells in the tumor microenvironment (including macrophages, neutrophils, natural killer cells, T cells, and cancer-associated fibroblasts) and related new anti-tumor strategies are also summarized. In conclusion, recent advances in anti-tumor strategies targeting nutrient blockade are reviewed, and the challenges and prospects of these anti-tumor strategies are discussed, which are of theoretical significance for optimizing the clinical application of tumor nutrition deprivation strategies.

We previously developed Salmonella typhimurium A1-R, which selectively targets and kills tumors. In the present study, we established recombinant methioninase (rMETase)-producing Salmonella typhimurium A1-R (A1-R-rMETase), by transfer of the Pseudomonas putida methioninase gene, to target methionine addiction of syngeneic-cancer mouse models.

A plasmid containing the Pseudomonas putida methioninase gene was extracted from METase-producing recombinant E. coli and inserted into Salmonella typhimurium A1-R using electroporation. Lewis Lung Carcinoma (LLC) cells (106) were injected subcutaneously in male C57BL/6 mice aged 4-6 weeks. We determined that 108 Salmonella typhimurium A1-R-rMETase administered iv was a safe dosage in C57BL/6 mice and was used for efficacy studies on LLC tumors in C57BL/6 mice. Tumor size was measured with calipers three times per week for 3 weeks. On day 22, tumor methionine levels were measured using HPLC in the control mice injected with phosphate-buffered saline (PBS) and the mice injected with Salmonella typhimurium A1-R-rMETase.

The mean LLC tumor size of each group on day 22 was as follows: PBS control: 741.5 mm3; mice injected with Salmonella typhimurium A1-R: 566.3 mm3 (p=0.370); and mice injected with Salmonella typhimurium A1-R-rMETase: 198.8 mm3 (p=0.0003 vs control and p=0.0117 vs. Salmonella A1-R). The mice injected with Salmonella typhimurium A1-R-rMETase showed a significantly lower mean tumor methionine level than mice injected with PBS (5.9 nM/mg protein vs 11.1 nM/mg protein, p=0.0095). Salmonella typhimurium A1-R-rMETase grew continuously in the tumors but not in the liver or spleen.

Tumor-targeting Salmonella typhimurium A1-R engineered to express the Pseudomonas putida methioninase gene, inhibited LLC tumor growth in a syngeneic mouse model and reduced the methionine level in the tumor. Salmonella typhimurium A1-R-rMETase combines the tumor targeting and killing capability of Salmonella typhimurium A1-R plus rMETase which targets the methionine addiction of cancer.

Endometrial receptivity and maternal-fetal immune tolerance are two crucial processes for a successful pregnancy. However, the molecular mechanisms of nutrition involved are largely unexplored. Here, we showed that maternal methionine supply significantly improved pregnancy outcomes, which was closely related to interleukin-5 (IL-5) concentration. Mechanistically, methionine induced embryonic IL-5 secretion, which enhanced the conversion of CD4+ T cells to IL-5+ Th2 cells in the uterus, thereby improving maternal-fetal immune tolerance. Meanwhile, methionine-mediated IL-5 secretion activated the nuclear factor κB (NF-κB) pathway and enhanced integrin αvβ3 expression in endometrial cells, which improved endometrial receptivity. Further, methionine strongly influenced the DNA methylation and transcription levels of the transcription factor eomesodermin (Eomes), which bound directly to the IL-5 promoter region and inhibited IL-5 transcription. Methionine modulated IL-5 transcription, maternal-fetal immune tolerance, and endometrial receptivity via its effects on Eomes. This study reveals the crucial functions of methionine and IL-5 and offers a potential nutritional strategy for successful pregnancy.

The incidence of gastric cancer remains high and poses a serious threat to human health. Recent comprehensive investigations into amino acid metabolism and immune system components within the tumor microenvironment have elucidated the functional interactions between tumor cells, immune cells, and amino acid metabolism. This study reviews the characteristics of amino acid metabolism in gastric cancer, with a particular focus on the metabolism of methionine, cysteine, glutamic acid, serine, taurine, and other amino acids. It discusses the relationship between these metabolic processes, tumor development, and the body's anti-tumor immunity, and analyzes the importance of targeting amino acid metabolism in gastric cancer for chemotherapy and immunotherapy.

Clear-cell renal cell carcinoma (ccRCC) is the most common subtype of kidney malignancy. ccRCC is considered a major health concern worldwide because its numbers of incidences and deaths continue to rise and are predicted to continue rising in the foreseeable future. Therefore new strategy for early diagnosis and therapeutics for this disease is urgently needed. The discovery of cancer stem cells (CSCs) offers hope for early cancer detection and treatment. However, there has been no definitive identification of these cancer progenitors for ccRCC. A majority of ccRCC is characterized by the loss of the von Hippel-Lindau (VHL) tumor suppressor gene function. Recent advances in genome analyses of ccRCC indicate that in ccRCC, tumor-initiating cells (TICs) and metastasis-initiating cells (MICs) are two distinct groups of progenitors. MICs result from various genetic changes during subclonal evolution, while TICs reside in the stem of the ccRCC phylogenetic tree of clonal development. TICs likely originate from kidney tubule progenitor cells bearing VHL gene inactivation, including chromatin 3p loss. Recent studies also point to the importance of microenvironment reconstituted by the VHL-deficient kidney tubule cells in promoting ccRCC initiation and progression. These understandings should help define the progenitors of ccRCC and facilitate early detection and treatment of this disease.

S-adenosylmethionine (SAMe) is a key methyl donor that plays a critical role in a variety of cellular processes, such as DNA, RNA and protein methylation, essential for maintaining genomic stability, regulating gene expression and maintaining cellular homeostasis. The involvement of SAMe in cancer pathogenesis is multifaceted, as through its multiple cellular functions, it can influence tumor initiation, progression and therapeutic resistance. In addition, the connection of SAMe with polyamine synthesis and oxidative stress management further underscores its importance in cancer biology. Recent studies have highlighted the potential of SAMe as a biomarker for cancer diagnosis and prognosis. Furthermore, the therapeutic implications of SAMe are promising, with evidence suggesting that SAMe supplementation or modulation could improve the efficacy of existing cancer treatments by restoring proper methylation patterns and mitigating oxidative damage and protect against damage induced by chemotherapeutic drugs. Moreover, targeting methionine cycle enzymes to both regulate SAMe availability and SAMe-independent regulatory effects, particularly in methionine-dependent cancers such as colorectal and lung cancer, presents a promising therapeutic approach. Additionally, exploring epitranscriptomic regulations, such as m6A modifications, and their interaction with non-coding RNAs could enhance our understanding of tumor progression and resistance mechanisms. Precision medicine approaches integrating patient subtyping and combination therapies with chemotherapeutics, such as decitabine or doxorubicin, together with SAMe, can enhance chemosensitivity and modulate epigenomics, showing promising results that may improve treatment outcomes. This review comprehensively examines the various roles of SAMe in cancer pathogenesis, its potential as a diagnostic and prognostic marker, and its emerging therapeutic applications. While SAMe modulation holds significant promise, challenges such as bioavailability, patient stratification and context-dependent effects must be addressed before clinical implementation. In addition, better validation of the obtained results into specific cancer animal models would also help to bridge the gap between research and clinical practice.

Chemotherapy resistance in osteosarcoma results in a very poor patient prognosis, with the 5-year survival rate of approximately 20%, which not improved for over three decades; thus, the development of novel therapeutic strategies is required. Methionine addiction is a fundamental and general hallmark of cancer, termed the Hoffman effect. Cancer cells need larger amounts of exogenous methionine in order to grow compared to normal cells, despite their ability to synthesize normal or greater amounts of methionine from homocysteine, due to increased transmethylation reactions in cancer cells. Methionine restriction therapy, including recombinant methioninase (rMETase), arrests cancer cells in the late-S/G2 phase of the cell cycle by targeting methionine addiction. First-line chemotherapy for osteosarcoma, including methotrexate (MTX), doxorubicin (DOX), and cisplatinum (CDDP), targets cells in the S/G2-phase, where cancer cells are also inhibited by methionine restriction, resulting in the synergy of methionine restriction to overcome drug resistance. In the present review, we describe the synergistic efficacy of conventional chemotherapy and methionine restriction therapy, including rMETase, in overcoming the drug resistance of osteosarcoma. The clinical potential of this new paradigm to overcome the drug resistance of osteosarcoma is discussed.

Parkinson's disease (PD) is an incurable, progressive and common movement disorder that is increasing in incidence globally because of population aging. We hypothesized that the landscape of rare, protein-altering variants could provide further insights into disease pathogenesis. Here we performed whole-exome sequencing followed by gene-based tests on 4,298 PD cases and 5,512 controls of Asian ancestry. We showed that GBA1 and SMPD1 were significantly associated with PD risk, with replication in a further 5,585 PD cases and 5,642 controls. We further refined variant classification using in vitro assays and showed that SMPD1 variants with reduced enzymatic activity display the strongest association (<44% activity, odds ratio (OR) = 2.24, P = 1.25 × 10-15) with PD risk. Moreover, 80.5% of SMPD1 carriers harbored the Asian-specific p.Pro332Arg variant (OR = 2.16; P = 4.47 × 10-8). Our findings highlight the utility of performing exome sequencing in diverse ancestry groups to identify rare protein-altering variants in genes previously unassociated with disease.

Pancreatic cancer is a highly aggressive neoplasm characterized by poor diagnosis. Amino acids play a prominent role in the occurrence and progression of pancreatic cancer as essential building blocks for protein synthesis and key regulators of cellular metabolism. Understanding the interplay between pancreatic cancer and amino acid metabolism offers potential avenues for improving patient clinical outcomes.

A comprehensive analysis integrating 10 machine learning algorithms was executed to pinpoint amino acid metabolic signature. The signature was validated across both internal and external cohorts. Subsequent GSEA was employed to unveil the enriched gene sets and signaling pathways within high- and low-risk subgroups. TMB and drug sensitivity analyses were carried out via Maftools and oncoPredict R packages. CIBERSORT and ssGSEA were harnessed to delve into the immune landscape disparities. Single-cell transcriptomics, qPCR, and Immunohistochemistry were performed to corroborate the expression levels and prognostic significance of this signature.

A four gene based amino acid metabolic signature with superior prognostic capabilities was identified by the combination of 10 machine learning methods. It showed that the novel prognostic model could effectively distinguish patients into high- and low-risk groups in both internal and external cohorts. Notably, the risk score from this novel signature showed significant correlations with TMB, drug resistance, as well as a heightened likelihood of immune evasion and suboptimal responses to immunotherapeutic interventions.

Our findings suggested that amino acid metabolism-related signature was closely related to the development, prognosis and immune microenvironment of pancreatic cancer.

Yes-associated protein (YAP) activation confers resistance to chemotherapy and targeted therapy. Methionine participates in cellular processes by converting to methyl donor for the methylation of DNA, RNA and protein. However, it remains unclear whether methionine affects drug resistance by influencing YAP activity. In this study, we report that methionine deprivation remarkably suppresses the transcriptional activity of YAP-TEAD in cancer cells. Methionine promotes PRMT1-catalyzed asymmetric dimethylation at R124 of YAP (YAP R124me2a). Mimicking of YAP methylation abolishes the reduction effect of methionine-restricted diet on YAP-induced drug resistance. YAP activates the transcription of SLC43A2, the methionine transporter, to increase methionine uptake in cancer cells. Knockdown of SLC43A2 decreases the level of YAP R124me2a. BCH, the inhibitor of SLC43A2, sensitizes tumors to anticancer drugs. Thus, our results unravel the positive feedback between YAP R124 methylation and SLC43A2 that contributes to anticancer drug resistance. Disrupting this positive feedback could be a potential strategy for cancer therapy.

As an essential branched amino acid, valine is pivotal for protein synthesis, neurological behaviour, haematopoiesis and leukaemia progression1-3. However, the mechanism by which cellular valine abundancy is sensed for subsequent cellular functions remains undefined. Here we identify that human histone deacetylase 6 (HDAC6) serves as a valine sensor by directly binding valine through a primate-specific SE14 repeat domain. The nucleus and cytoplasm shuttling of human, but not mouse, HDAC6 is tightly controlled by the intracellular levels of valine. Valine deprivation leads to HDAC6 retention in the nucleus and induces DNA damage. Mechanistically, nuclear-localized HDAC6 binds and deacetylates ten-eleven translocation 2 (TET2) to initiate active DNA demethylation, which promotes DNA damage through thymine DNA glycosylase-driven excision. Dietary valine restriction inhibits tumour growth in xenograft and patient-derived xenograft models, and enhances the therapeutic efficacy of PARP inhibitors. Collectively, our study identifies human HDAC6 as a valine sensor that mediates active DNA demethylation and DNA damage in response to valine deprivation, and highlights the potential of dietary valine restriction for cancer treatment.

Metastatic prostate cancer is a recalcitrant disease. Our laboratory has previously treated prostate-cancer patients with methionine restriction effected by a low methionine diet and oral recombinant methioninase (o-rMETase), both alone and in combination with other agents. The present case is a 66-year-old patient who had a radical prostatectomy in 2019 with a Gleason score 3+3 and 3+4. The patient subsequently was treated with immunotherapy in 2021 and salvage proton-beam therapy in 2022, and subsequently treated only with o-rMETase and a low-methionine diet. The aim of the present study was to determine the long-term efficacy of methionine restriction on the patient's prostate cancer.

Starting in September 2022, the patient started methionine restriction with a low methionine-diet and o-rMETase, twice a day, after meals, at 250 units/dose. Since the start of methionine restriction, the patients' prostate-specific antigen (PSA) has remained stable, under 2 ng/ml. Positron emission tomography/computed tomography (PET/CT) and prostate specific membrane antigen (PSMA)-PET imaging indicated in September 2023 a right pelvic-side-wall metastatic lymph node that was stable when the PSMA-PET scan was repeated in March 2024, with the standardized uptake value (SUV) decreasing from 19.39 to 14.98. A very small possible metastatic external-iliac lymph node was detected in March 2024. Thus, the lymph-node metastases were stable and did not increase.

During the time the patient was on methionine restriction alone, effected by a low-methionine diet and o-rMETase, the metastatic prostate cancer did not progress. Further clinical studies of methionine restriction and metastatic prostate cancer are needed, including randomized clinical trials.

For second-line chemotherapy of soft-tissue sarcoma, gemcitabine is administered in combination with docetaxel. However, more effective treatments are required for advanced soft-tissue sarcoma, where the efficacy is limited. The purpose of the present study was to compare the efficacy of rMETase and gemcitabine against HT1080 human fibrosarcoma cells and Hs27 normal fibroblasts, as well as to identify and effectively treat HT1080 cells that are resistant to gemcitabine associated with elevated c-MYC.

Cell viability was measured with the WST-8 reagent. Four groups of in vitro tests were conducted involving HT1080 and Hs27 cells: gemcitabine alone, rMETase alone, and a combination of gemcitabine plus rMETase. Gemcitabine resistant cells (GR-HT1080) were established by culturing HT-1080 cells in increasing concentrations of gemcitabine, ranging from 0.016 nM to 16 nM over five months. Western immunoblotting was performed to measure c-MYC levels in HT1080 and GR-HT1080 cells.

Gemcitabine had an IC50 of 12.8 nM against HT1080 cells, 30.8 nM against GR-HT1080 cells, and 4.48 nM against Hs27 cells. The rMETase IC50 value for HT1080 was 0.75 U/ml. The IC50 value of rMETase for GR-HT1080 cells was 0.85 U/ml. The IC50 value for rMETase on Hs27 cells was 0.93 U/ml. Gemcitabine and rMETase demonstrated synergy in killing fibrosarcoma cells, but no synergy was observed on normal fibroblasts. The c-MYC level that was more than 5.1 times higher in GR-HT1080 cells compared to HT-1080 cells. Both the parental HT1080 cells and the GR-HT1080 cells had a similar high sensitivity to rMETase alone.

rMETase may be used as a future clinical strategy to overcome gemcitabine resistance in sarcoma.

Chronic lymphocytic leukemia (CLL) is currently incurable. CLL is characterized by disordered DNA methylation. The aim of the present study was to target methylation with methionine restriction in a patient with progressive CLL.

Methionine restriction for the patient was achieved with a low-methionine vegan diet and oral recombinant methioninase (o-rMETase). The patient also received rituximab, once per week for four weeks, and acalabrutinib 100 mg, twice daily (bid) continuously. The patient's white blood cell count decreased by 95% from peak levels and extensive lymphadenopathy disappeared during combination treatment with o-rMETase, rituximab, and acalabrutinib.

The combination of methionine restriction and first-line chemotherapy resulted in an apparent complete response (CR) in a CLL patient, a rare event. The duration of the CR will be monitored, and additional CLL patients will be treated similarly in the future.

Ifosfamide is used clinically with doxorubicin as first-line chemotherapy for soft-tissue sarcoma. However, ifosfamide efficacy for soft-tissue sarcoma is limited due to frequent occurence of ifosfamide resistance and thus more effective therapy is needed. The present study aimed to determine the synergy of recombinant methioninase (rMETase) plus ifosfamide against HT1080 human fibrosarcoma cells in vitro. Additionally, the present study also investigated the efficacy of a methionine-restricted diet combined with ifosfamide in nude-mouse models of ifosfamide-resistant HT1080 (IR-HT1080).

Cell viability for HT1080 human fibrosarcoma cells was determined in four groups in vitro: No treatment control; ifosfamide alone; rMETase alone; and a combination of ifosfamide plus rMETase. HT1080 tumors were established in nude mice subcutaneously. The HT1080 tumor models were treated by administering ifosfamide by intraperitoneal injection twice a week, for a total of 11 doses. Surviving tumors were considered ifosfamide resistant (IR-HT1080). Four groups of IR-HT1080 nude-mouse models were subsequently established: Group 1 was a no-treatment control, Group 2 received ifosfamide, Group 3 was given a methionine-restricted diet (MR), and Group 4 received ifosfamide plus MR. Additionally, two groups of nude mice with parental HT1080 subcutaneous tumors were included: Group 5 was a no-treatment control, and Group 6 received ifosfamide for comparison.

The 50% inhibitory concentration (IC50) for ifosfamide against HT1080 cells was 0.38 mM. The IC50 for rMETase was 0.75 U/ml for HT1080 cells (data from [4]). The combination of rMETase (0.75 U/ml) plus ifosfamide (0.38 mM) was synergistic against HT1080 fibrosarcoma cells in vitro. The combination of ifosfamide plus MR eradicated the IR-HT1080 tumors in nude-mouse models, while each treatment alone achieved limited tumor inhibition.

The present results suggest the combination of MR and ifosfamide has promising potential for overcoming ifosfamide resistance in future clinical applications.

The effect of the serine/glycine-free diet (-SG diet) on colorectal cancer (CRC) remains unclear; meanwhile, programmed death-1 (PD-1) inhibitors are less effective for most CRC patients. Here, we demonstrate that the -SG diet inhibits CRC growth and promotes the accumulation of cytotoxic T cells to enhance antitumor immunity. Additionally, we also identified the lactylation of programmed death-ligand 1 (PD-L1) in tumor cells as a mechanism of immune evasion during cytotoxic T cell-mediated antitumor responses, and blocking the PD-1/PD-L1 signaling pathway is able to rejuvenate the function of CD8+ T cells recruited by the -SG diet, indicating the potential of combining the -SG diet with immunotherapy. We conducted a single-arm, phase I study (ChiCTR2300067929). The primary outcome suggests that the -SG diet is feasible and safe for regulating systemic immunity. Secondary outcomes include patient tolerability and potential antitumor effects. Collectively, our findings highlight the promising therapeutic potential of the -SG diet for treating solid tumors.

Radiofrequency ablation (RFA), a critical therapy for hepatocellular carcinoma (HCC), carries a significant risk of recurrence and metastasis, particularly owing to mechanisms involving immune evasion and antigen downregulation via epigenetic modifications. This study introduces a "nano-epidrug" named MFMP. MFMP, which is composed of hollow mesoporous manganese dioxide (MnO2) nanoparticles, FIDAS-5 as an MAT2A inhibitor, macrophage membrane, and anti-PD-L1 (aPD-L1), targets HCC cells. By selectively binding to these cells, MFMP initially reverses immune suppression via PD-L1 inhibition. After endocytosis, MFMP disassembles in the tumor microenvironment, releasing FIDAS-5 and Mn2+. FIDAS-5 prevents cGAS methylation, whereas Mn2+ aids STING pathway restoration. In addition, FIDAS-5 reduces m6A RNA modification, suppressing EGFR expression. These changes enhance HCC antigenicity to promote cytotoxic T cell recognition and cytotoxic killing. Furthermore, MFMP mediates immunogenic cell death in HCC by synergizing with RFA through cGAS DNA demethylation, EGFR mRNA demethylation, and TBK1 protein phosphorylation, thereby inhibiting recurrence and metastasis and enhancing immune memory. Thus, MFMP is a potential adjunctive therapy requiring clinical validation.

N-glycosylation can have a profound effect on the quality of mAb therapeutics. In biomanufacturing, one of the ways to influence N-glycosylation patterns is by altering the media used to grow mAb cell expression systems. Here, we explore the potential of machine learning (ML) to forecast the abundances of N-glycan types based on variables related to the growth media. The ML models exploit a dataset consisting of detailed glycomic characterisation of Anti-HER fed-batch bioreactor cell cultures measured daily under 12 different culture conditions, such as changes in levels of dissolved oxygen, pH, temperature, and the use of two different commercially available media. By performing spent media quantitation and subsequent calculation of pseudo cell consumption rates (termed media markers) as inputs to the ML model, we were able to demonstrate a small subset of media markers (18 selected out of 167 mass spectrometry peaks) in a Chinese Hamster Ovary (CHO) cell cultures are important to model N-glycan relative abundances (Regression - correlations between 0.80-0.92; Classification - AUC between 75.0-97.2). The performances suggest the ML models can infer N-glycan critical quality attributes from extracellular media as a proxy. Given its accuracy, we envisage its potential applications in biomaufactucuring, especially in areas of process development, downstream and upstream bioprocessing.

Glioblastoma (GBM) is uniformly lethal due to profound treatment resistance. Altered cellular metabolism is a key mediator of GBM treatment resistance. Uptake of the essential sulfur-containing amino acid methionine is drastically elevated in GBMs compared to normal cells, however, it is not known how this methionine is utilized or whether it relates to GBM treatment resistance. Here, we find that radiation acutely increases the levels of methionine-related metabolites in a variety of treatment-resistant GBM models. Stable isotope tracing studies further revealed that radiation acutely activates methionine to S-adenosyl methionine (SAM) conversion through an active signaling event mediated by the kinases of the DNA damage response. In vivo tumor SAM synthesis increases after radiation, while normal brain SAM production remains unchanged, indicating a tumor- specific metabolic alteration to radiation. Pharmacological and dietary strategies to block methionine to SAM conversion slowed DNA damage response and increased cell death following radiation in vitro. Mechanistically, these effects are due to depletion of DNA repair proteins and are reversed by SAM supplementation. These effects are selective to GBMs lacking the methionine salvage enzyme methylthioadenosine phosphorylase. Pharmacological inhibition of SAM synthesis hindered tumor growth in flank and orthotopic in vivo GBM models when combined with radiation. By contrast, methionine depletion does not reduce tumor SAM levels and fails to radiosensitize intracranial models, indicating depleting SAM, as opposed to simply lowering methionine, is critical for hindering tumor growth in intracranial models of GBM. These results highlight a new signaling link between DNA damage and SAM synthesis and define the metabolic fates of methionine in GBM in vivo . Inhibiting radiation-induced SAM synthesis slows DNA repair and augments radiation efficacy in GBM. Using MAT2A inhibitors to deplete SAM may selectively overcome treatment resistance in GBMs with defective methionine salvage while sparing normal brain.

Metabolic and transcriptional reprogramming are crucial hallmarks of carcinogenesis that present exploitable vulnerabilities for the development of targeted anticancer therapies. Through controlling the balance of the cellular methionine (MET) metabolite pool, MET adenosyl transferase 2 alpha (MAT2A) regulates crucial steps during metabolism and the epigenetic control of transcription. The aberrant function of MAT2A has been shown to drive malignant transformation through metabolic addiction, transcriptional rewiring, and immune modulation of the tumor microenvironment (TME). Moreover, MAT2A sustains the survival of 5'-methylthioadenosine phosphorylase (MTAP)-deficient tumors, conferring synthetic lethality to cancers with MTAP loss, a genetic alteration that occurs in ∼15% of all cancers. Thus, the pharmacological inhibition of MAT2A is emerging as a desirable therapeutic strategy to combat tumor growth. Here, we review the latest insights into MAT2A biology, focusing on its roles in both metabolic addiction and gene expression modulation in the TME, outline the current landscape of MAT2A inhibitors, and highlight the most recent clinical developments and opportunities for MAT2A inhibition as a novel anti-tumor therapy.

Endometrial cancer (EC) is one of the most common gynecologic malignancies, which lacking effective drugs for intractable conditions or patients unsuitable for surgeries. Recently, the patient-derived organoids (PDOs) are found feasible for cancer research and drug discoveries. Here, we have successfully established a panel of PDOs from EC and conducted drug repurposing screening and mechanism analysis for cancer treatment. We confirmed that the regulatory β subunit of methionine adenosyltransferase (MAT2B) is highly correlated with malignant progression in endometrial cancer. Through drug screening on PDOs, we identify JX24120, chlorpromazine derivative, as a specific inhibitor for MAT2B, which directly binds to MAT2B (Kd = 4.724 μM) and inhibits the viability of EC PDOs and canonical cell lines. Correspondingly, gene editing assessment demonstrates that JX24120 suppresses tumor growth depending on the presence of MAT2B in vivo and in vitro. Mechanistically, JX24120 induces inhibition of S-adenosylmethionine (SAMe) synthesis, leading to suppressed mTORC1 signaling, abnormal energy metabolism and protein synthesis, and eventually apoptosis. Taken together, our study offers a novel approach for drug discovery and efficacy assessment by using the PDOs models. These findings suggest that JX24120 may be a potent MAT2B inhibitor and will hopefully serve as a prospective compound for endometrial cancer therapy.