Integrated Metabolic Profiling and Transcriptional Analysis Reveals Therapeutic Modalities for Targeting Rapidly Proliferating Breast Cancers

GAMT facilitates tumor progression via inhibiting p53 in clear cell renal cell carcinoma

BACKGROUND

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.

RESULTS

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.

CONCLUSIONS

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.

Lipid metabolic reprograming: the unsung hero in breast cancer progression and tumor microenvironment

Aberrant lipid metabolism is a well-recognized hallmark of cancer. Notably, breast cancer (BC) arises from a lipid-rich microenvironment and depends significantly on lipid metabolic reprogramming to fulfill its developmental requirements. In this review, we revisit the pivotal role of lipid metabolism in BC, underscoring its impact on the progression and tumor microenvironment. Firstly, we delineate the overall landscape of lipid metabolism in BC, highlighting its roles in tumor progression and patient prognosis. Given that lipids can also act as signaling molecules, we next describe the lipid signaling exchanges between BC cells and other cellular components in the tumor microenvironment. Additionally, we summarize the therapeutic potential of targeting lipid metabolism from the aspects of lipid metabolism processes, lipid-related transcription factors and immunotherapy in BC. Finally, we discuss the possibilities and problems associated with clinical applications of lipid‑targeted therapy in BC, and propose new research directions with advances in spatiotemporal multi-omics.

Altered Arginine Metabolism Affects Proliferation and Radiosensitivity of Keloids

Keloid is characterised by the reprogramming of cellular metabolism, wherein keloid cells adapt their metabolic pathways to meet the demands for energy and biosynthetic precursors. Investigating the intricate relationship between cellular metabolism and the biological behaviour of keloid holds the potential to yield novel therapeutic strategies for keloid. To elucidate the molecular alterations and potential underlying regulatory mechanisms in keloids, we created comprehensive metabolic profiling at the pathway level by analysing metabolomic, transcriptomic and single-cell RNA-sequencing data from keloids and adjacent skin. Viability assay and clonogenic assay were performed to validate the function of the metabolic pathway(s) in primary keloid fibroblast cells. Integrated analysis revealed an upregulation of arginine and proline metabolism in keloids. According to single-cell RNA-seq data, elevated expression of genes related to arginine and proline metabolism, such as P4HA3, P4HA2, P4HA1, PYCR1, OAT and ASS1, was predominately highly expressed in fibroblast-2. Fibroblast-2 displayed more obvious phenotypes of mesenchymal fibroblast. Critical genes from integrated analysis including P4HA3, P4HA2, P4HA1, PYCR1 and AZIN2, and metabolites including fumaric acid and 2-oxo-5-amino-pentanoic acid showed prognostic relevance with disease-free survival of keloid. Additionally, an In vitro study showed that arginine deprivation therapy (ADT) inhibited and radiosensitised the proliferation of keloid-derived fibroblasts. In conclusion, our thorough multiomics study deepens our understanding of the link between arginine and proline metabolism and keloid proliferation and radiosensitivity. Elevated activity of arginine and proline metabolism in mesenchymal fibroblasts may be a potential therapeutic pathway for keloid.

BBOX1 restrains TBK1-mTORC1 oncogenic signaling in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC), a metabolic disease originating from renal proximal convoluted tubule (PCT) epithelial cells, remains incompletely understood in terms of its initiating signaling events. Here, we identify γ-butyrobetaine hydroxylase 1 (BBOX1), a key enzyme in carnitine synthesis predominantly expressed in PCT cells, as a tumor suppressor in ccRCC. BBOX1 expression is lost during ccRCC malignant transformation, and its restoration reduces cell viability in physiological medium and inhibits xenograft tumor growth. Transcriptomic analyses reveal that BBOX1 suppresses critical metabolic pathways including mTORC1 signaling and glycolysis in ccRCC. Further, we identify TANK-binding kinase 1 (TBK1) as an essential mediator of mTORC1 and glycolysis activation and as a target of BBOX1-mediated tumor suppression. Mechanistically, BBOX1 disrupts TBK1 activation by preventing its interaction with the upstream activator doublecortin-like kinase 2 (DCLK2). This BBOX1-DCLK2-TBK1 axis unveils an important mechanism in ccRCC metabolic dysregulation and highlights potential therapeutic strategies.

Metabolic Profiling of Breast Cancer Cell Lines: Unique and Shared Metabolites

Breast Cancer (BrCa) exhibits a high phenotypic heterogeneity, leading to the emergence of aggressive clones and the development of drug resistance. Considering the BrCa heterogeneity and that metabolic reprogramming is a cancer hallmark, we selected seven BrCa cell lines with diverse subtypes to provide their comprehensive metabolome characterization: five lines commonly used (SK-Br-3, T-47D, MCF-7, MDA-MB-436, and MDA-MB-231), and two patient-derived xenografts (Hbcx39 and Hbcx9). We characterized their endometabolomes using 1H-NMR spectroscopy. We found distinct metabolite profiles, with certain metabolites being common but differentially accumulated across the selected BrCa cell lines. High levels of glycine, lactate, glutamate, and formate, metabolites known to promote invasion and metastasis, were detected in all BrCa cells. In our experiment setting were identified unique metabolites to specific cell lines: xanthine and 2-oxoglutarate in SK-Br-3, 2-oxobutyrate in T-47D, cystathionine and glucose-1-phosphate in MCF-7, NAD+ in MDA-MB-436, isocitrate in MDA-MB-231, and NADP+ in Hbcx9. The unique and enriched metabolites enabled us to identify the metabolic pathways modulated in a cell-line-specific manner, which may represent potential candidate targets for therapeutic intervention. We believe this study may contribute to the functional characterization of BrCa cells and assist in selecting appropriate cell lines for drug-response studies.

Patient-Derived Xenografts of Breast Cancer

Patient-derived xenografts (PDX) of breast cancer, obtained from the engraftment of tumour samples into immunodeficient mice, are the most effective preclinical models for studying the biology of human breast cancer and for the evaluation of new anti-cancer treatments. Notably, breast cancer PDX preserve the phenotypic and molecular characteristics of the donor tumours and reproduce the diversity of breast cancer. This preservation of breast cancer biology involves a number of different aspects, including tumour architecture and morphology, patterns of genomic alterations and gene expression, mutational status, and intra-tumour heterogeneity. For these reasons, these models have a strong predictive value in the translation of cancer therapeutics into clinical settings and can be considered as powerful and clinically relevant research tools for the identification of new treatments, mechanisms of drug resistance, and predictive biomarkers. PDX models have also been successfully used to analyse breast cancer metastasis and persister cancer cells surviving chemotherapy. Limitations of breast cancer PDX include the lack of a human immune system and the low take rate, especially for estrogen receptor (ER) and HER2-positive subtypes.

Metabolomic and transcriptomic insights into the mechanisms of renal ischemia-reperfusion injury progression

Renal ischemia-reperfusion injury (IRI) is an important cause of acute kidney injury (AKI). However, the pathophysiological changes and mechanisms during IRI-AKI progression remain unclear. This study aims toinvestigate the potential mechanisms in the progression of IRI-AKI by integrating metabolomics and transcriptomics data, providing a reference for the subsequent identification of biomarkers and therapeutic targets. IRI-AKI rat models with 30 min of ischemia and 24-72 h of reperfusion surgery simulating the progression of AKI were established. Compared to the control group underwent sham surgery (NC group), most of the differentially expressed metabolites (DEMs) in IRI-AKI 24 h and IRI-AKI 72 h decreased, mainly including amino acids, organic acids, and carnitines. Additionally, we found that DEMs were mainly enriched in amino acid-related pathways, among which valine, leucine, and isoleucine biosynthesis were dramatically altered in all comparisons. Transcriptomics revealed that differentially expressed genes (DEGs) were primarily involved in amino acid, lipid, and fatty acid metabolism. By integrating metabolomics and transcriptomics, we found valine, leucine, and isoleucine biosynthesis play key roles in IRI-AKI development. Our findings concluded that valine, leucine, and isoleucine pathways are hubs that potentially connect transcriptomes to metabolomes, providing new insights regarding the pathogenesis of IRI-AKI and its potential biomarkers and therapeutic strategies.

Single-cell transcriptional atlas of human breast cancers and model systems

BACKGROUND

Breast cancer's complex transcriptional landscape requires an improved understanding of cellular diversity to identify effective treatments. The study of genetic variations among breast cancer subtypes at single-cell resolution has potential to deepen our insights into cancer progression.

METHODS

In this study, we amalgamate single-cell RNA sequencing data from patient tumours and matched lymph metastasis, reduction mammoplasties, breast cancer patient-derived xenografts (PDXs), PDX-derived organoids (PDXOs), and cell lines resulting in a diverse dataset of 117 samples with 506 719 total cells. These samples encompass hormone receptor positive (HR+), human epidermal growth factor receptor 2 positive (HER2+), and triple-negative breast cancer (TNBC) subtypes, including isogenic model pairs. Herein, we delineated similarities and distinctions across models and patient samples and explore therapeutic drug efficacy based on subtype proportions.

RESULTS

PDX models more closely resemble patient samples in terms of tumour heterogeneity and cell cycle characteristics when compared with TNBC cell lines. Acquired drug resistance was associated with an increase in basal-like cell proportions within TNBC PDX tumours as defined with SCSubtype and TNBCtype cell typing predictors. All patient samples contained a mixture of subtypes; compared to primary tumours HR+ lymph node metastases had lower proportions of HER2-Enriched cells. PDXOs exhibited differences in metabolic-related transcripts compared to PDX tumours. Correlative analyses of cytotoxic drugs on PDX cells identified therapeutic efficacy was based on subtype proportion.

CONCLUSIONS

We present a substantial multimodel dataset, a dynamic approach to cell-wise sample annotation, and a comprehensive interrogation of models within systems of human breast cancer. This analysis and reference will facilitate informed decision-making in preclinical research and therapeutic development through its elucidation of model limitations, subtype-specific insights and novel targetable pathways.

KEY POINTS

Patient-derived xenografts models more closely resemble patient samples in tumour heterogeneity and cell cycle characteristics when compared with cell lines. 3D organoid models exhibit differences in metabolic profiles compared to their in vivo counterparts. A valuable multimodel reference dataset that can be useful in elucidating model differences and novel targetable pathways.

MYC Induces Oncogenic Stress through RNA Decay and Ribonucleotide Catabolism in Breast Cancer

Upregulation of MYC is a hallmark of cancer, wherein MYC drives oncogenic gene expression and elevates total RNA synthesis across cancer cell transcriptomes. Although this transcriptional anabolism fuels cancer growth and survival, the consequences and metabolic stresses induced by excess cellular RNA are poorly understood. Herein, we discover that RNA degradation and downstream ribonucleotide catabolism is a novel mechanism of MYC-induced cancer cell death. Combining genetics and metabolomics, we find that MYC increases RNA decay through the cytoplasmic exosome, resulting in the accumulation of cytotoxic RNA catabolites and reactive oxygen species. Notably, tumor-derived exosome mutations abrogate MYC-induced cell death, suggesting excess RNA decay may be toxic to human cancers. In agreement, purine salvage acts as a compensatory pathway that mitigates MYC-induced ribonucleotide catabolism, and inhibitors of purine salvage impair MYC+ tumor progression. Together, these data suggest that MYC-induced RNA decay is an oncogenic stress that can be exploited therapeutically. Significance: MYC is the most common oncogenic driver of poor-prognosis cancers but has been recalcitrant to therapeutic inhibition. We discovered a new vulnerability in MYC+ cancer where MYC induces cell death through excess RNA decay. Therapeutics that exacerbate downstream ribonucleotide catabolism provide a therapeutically tractable approach to TNBC (Triple-negative Breast Cancer) and other MYC-driven cancers.

Investigating the therapeutic potential of hesperidin targeting CRISP2 in intervertebral disc degeneration and cancer risk mitigation

Background

Intervertebral disc degeneration (IDD) can lead to disc herniation and spinal instability, sometimes requiring surgical intervention. Currently, estrogen has a potential protective effect on IDD, and estrogen is associated with an increased risk of some cancers, such as breast and endometrial cancer. Therefore, it is important to identify natural compounds that estrogen analogues treat IDD while reducing the risk of tumor development.

Objective

This study aims to explore a natural metabolic treatment strategy by targeting CRISP2 with the natural compound Hesperidin to mimic the protective effects of estrogen on IDD and reduce the risk of tumor development.

Methods

Microarray data from healthy volunteers and IDD patients were extracted from the Gene Expression Omnibus (GEO) database, and RNA sequencing and clinical data from various cancer types were analyzed. Differentially expressed genes (DEGs) were identified using the Bioconductor Limma package, followed by principal component analysis, volcano plot, and heatmap visualization. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, CIBERSORT and ssGSEA immune cell infiltration assessments, survival analysis, metabolite enrichment analysis, and molecular docking were performed. Hesperidin's interaction with CRISP2 was further validated through molecular docking and experimental studies.

Results

Hesperidin significantly reduced the expression of CRISP2, iNOS, and COX2 in IDD models, decreased reactive oxygen species (ROS) and apoptosis, and diminished inflammatory markers. CIBERSORT and ssGSEA analyses revealed a correlation between CRISP2 and immune cell infiltration. Survival analysis demonstrated that CRISP2 expression levels were associated with patient survival across various cancer types. Hesperidin was found to mimic estrogen's effects on IDD and reduce tumor progression. Cell culture and experimental validation confirmed Hesperidin's protective effects on nucleus pulposus cells (NPCs).

Conclusion

Hesperidin, as a potential natural metabolic regulator, not only has therapeutic effects on IDD but may also synergize with estrogen therapy to promote spinal health without increasing cancer risk. This study presents a new clinical approach for IDD treatment and lays the foundation for further drug development and experimental research.

Patient-Derived-Xenografts in Mice: A Preclinical Platform for Cancer Research

The use of patient-derived xenografts (PDXs) has dramatically improved drug development programs. PDXs (1) reproduce the pathological features and the genomic profile of the parental tumors more precisely than other preclinical models, and (2) more faithfully predict therapy response. However, PDXs have limitations. These include the inability to completely capture tumor heterogeneity and the role of the immune system, the low engraftment efficiency of certain tumor types, and the consequences of the human-host interactions. Recently, the use of novel mouse strains and specialized engraftment techniques has enabled the generation of "humanized" PDXs, partially overcoming such limitations. Importantly, establishing, characterizing, and maintaining PDXs is costly and requires a significant regulatory, administrative, clinical, and laboratory infrastructure. In this review, we will retrace the historical milestones that led to the implementation of PDXs for cancer research, review the most recent innovations in the field, and discuss future avenues to tackle deficiencies that still exist.

Integrated Metabolomics and Transcriptomics Analysis of Anacardic Acid Inhibition of Breast Cancer Cell Viability

Anacardic acid (AnAc) inhibits the growth of estrogen receptor α (ERα)-positive MCF-7 breast cancer (BC) cells and MDA-MB-231 triple-negative BC (TNBC) cells, without affecting primary breast epithelial cells. RNA sequencing (seq) and network analysis of AnAc-treated MCF-7 and MDA-MB-231 cells suggested that AnAc inhibited lipid biosynthesis and increased endoplasmic reticulum stress. To investigate the impact of AnAc on cellular metabolism, a comprehensive untargeted metabolomics analysis was performed in five independent replicates of control versus AnAc-treated MCF-7 and MDA-MB-231 cells and additional TNBC cell lines: MDA-MB-468, BT-20, and HCC1806. An analysis of the global metabolome identified key metabolic differences between control and AnAc-treated within each BC cell line and between MCF-7 and the TNBC cell lines as well as metabolic diversity among the four TNBC cell lines, reflecting TNBC heterogeneity. AnAc-regulated metabolites were involved in alanine, aspartate, glutamate, and glutathione metabolism; the pentose phosphate pathway; and the citric acid cycle. Integration of the transcriptome and metabolome data for MCF-7 and MDA-MB-231 identified Signal transduction: mTORC1 downstream signaling in both cell lines and additional cell-specific pathways. Together, these data suggest that AnAc treatment differentially alters multiple pools of cellular building blocks, nutrients, and transcripts resulting in reduced BC cell viability.

Identifying prognostic markers in spatially heterogeneous breast cancer microenvironment

To gain deeper insights into the microenvironment of breast cancer, we utilized GeoMx Digital Spatial Profiling (DSP) technology to analyze transcripts from 107 regions of interest in 65 untreated breast cancer tissue samples. Our study revealed spatial heterogeneity in the expression of marker genes in tumor cell enriched, immune cell enriched, and normal epithelial areas. We evaluated a total of 55 prognostic markers in tumor cell enriched regions and 15 in immune cell enriched regions, identifying that tumor cell enriched regions had higher levels of follicular helper T cells, resting dendritic cells, and plasma cells than immune cell enriched regions, while the levels of resting CD4 memory in T cells and regulatory (Treg) T cells were lower. Additionally, we analyzed the heterogeneity of HLA gene families, immunological checkpoints, and metabolic genes in these areas. Through univariate Cox analysis, we identified 5 prognosis-related metabolic genes. Furthermore, we conducted immunostaining experiments, including EMILIN2, SURF4, and LYPLA1, to verify our findings. Our investigation into the spatial heterogeneity of the breast cancer tumor environment has led to the discovery of specific diagnostic and prognostic markers in breast cancer.

Emerging therapies in cancer metabolism

Metabolic reprogramming in cancer is not only a biological hallmark but also reveals treatment vulnerabilities. Numerous metabolic molecules have shown promise as treatment targets to impede tumor progression in preclinical studies, with some advancing to clinical trials. However, the intricacy and adaptability of metabolic networks hinder the effectiveness of metabolic therapies. This review summarizes the metabolic targets for cancer treatment and provides an overview of the current status of clinical trials targeting cancer metabolism. Additionally, we decipher crucial factors that limit the efficacy of metabolism-based therapies and propose future directions. With advances in integrating multi-omics, single-cell, and spatial technologies, as well as the ability to track metabolic adaptation more precisely and dynamically, clinicians can personalize metabolic therapies for improved cancer treatment.

Aberrant L-Fucose Accumulation and Increased Core Fucosylation Are Metabolic Liabilities in Mesenchymal Glioblastoma

Glioblastoma (GBM) is a common and deadly form of brain tumor in adults. Dysregulated metabolism in GBM offers an opportunity to deploy metabolic interventions as precise therapeutic strategies. To identify the molecular drivers and the modalities by which different molecular subgroups of GBM exploit metabolic rewiring to sustain tumor progression, we interrogated the transcriptome, the metabolome, and the glycoproteome of human subgroup-specific GBM sphere-forming cells (GSC). L-fucose abundance and core fucosylation activation were elevated in mesenchymal (MES) compared with proneural GSCs; this pattern was retained in subgroup-specific xenografts and in subgroup-affiliated human patient samples. Genetic and pharmacological inhibition of core fucosylation significantly reduced tumor growth in MES GBM preclinical models. Liquid chromatography-mass spectrometry (LC-MS)-based glycoproteomic screening indicated that most MES-restricted core-fucosylated proteins are involved in therapeutically relevant GBM pathological processes, such as extracellular matrix interaction, cell adhesion, and integrin-mediated signaling. Selective L-fucose accumulation in MES GBMs was observed using preclinical minimally invasive PET, implicating this metabolite as a potential subgroup-restricted biomarker.Overall, these findings indicate that L-fucose pathway activation in MES GBM is a subgroup-specific dependency that could provide diagnostic markers and actionable therapeutic targets.

SIGNIFICANCE

Metabolic characterization of subgroup-specific glioblastoma (GBM) sphere-forming cells identifies the L-fucose pathway as a vulnerability restricted to mesenchymal GBM, disclosing a potential precision medicine strategy for targeting cancer metabolism.

Ferroptosis heterogeneity in triple-negative breast cancer reveals an innovative immunotherapy combination strategy

Treatment of triple-negative breast cancer (TNBC) remains challenging. Deciphering the orchestration of metabolic pathways in regulating ferroptosis will provide new insights into TNBC therapeutic strategies. Here, we integrated the multiomics data of our large TNBC cohort (n = 465) to develop the ferroptosis atlas. We discovered that TNBCs had heterogeneous phenotypes in ferroptosis-related metabolites and metabolic pathways. The luminal androgen receptor (LAR) subtype of TNBC was characterized by the upregulation of oxidized phosphatidylethanolamines and glutathione metabolism (especially GPX4), which allowed the utilization of GPX4 inhibitors to induce ferroptosis. Furthermore, we verified that GPX4 inhibition not only induced tumor ferroptosis but also enhanced antitumor immunity. The combination of GPX4 inhibitors and anti-PD1 possessed greater therapeutic efficacy than monotherapy. Clinically, higher GPX4 expression correlated with lower cytolytic scores and worse prognosis in immunotherapy cohorts. Collectively, this study demonstrated the ferroptosis landscape of TNBC and revealed an innovative immunotherapy combination strategy for refractory LAR tumors.

Glutamine addiction promotes glucose oxidation in triple-negative breast cancer

Glutamine is a conditionally essential nutrient for many cancer cells, but it remains unclear how consuming glutamine in excess of growth requirements confers greater fitness to glutamine-addicted cancers. By contrasting two breast cancer subtypes with distinct glutamine dependencies, we show that glutamine-indispensable triple-negative breast cancer (TNBC) cells rely on a non-canonical glutamine-to-glutamate overflow, with glutamine carbon routed once through the TCA cycle. Importantly, this single-pass glutaminolysis increases TCA cycle fluxes and replenishes TCA cycle intermediates in TNBC cells, a process that achieves net oxidation of glucose but not glutamine. The coupling of glucose and glutamine catabolism appears hard-wired via a distinct TNBC gene expression profile biased to strip and then sequester glutamine nitrogen, but hampers the ability of TNBC cells to oxidise glucose when glutamine is limiting. Our results provide a new understanding of how metabolically rigid TNBC cells are sensitive to glutamine deprivation and a way to select vulnerable TNBC subtypes that may be responsive to metabolic-targeted therapies.