Metabolic reprogramming of cancer-associated fibroblasts and its effect on cancer cell reprogramming

The landscape of circRNAs in gliomas temozolomide resistance: Insights into molecular pathways

As the deadliest type of primary brain tumor, gliomas represent a significant worldwide health concern. Circular RNA (circRNA), a unique non-coding RNA molecule, seems to be one of the most alluring target molecules involved in the pathophysiology of many kinds of cancers. CircRNAs have been identified as prospective targets and biomarkers for the diagnosis and treatment of numerous disorders, particularly malignancies. Recent research has established a clinical link between temozolomide (TMZ) resistance and certain circRNA dysregulations in glioma tumors. CircRNAs may play a therapeutic role in controlling or overcoming TMZ resistance in gliomas and may provide guidance for a novel kind of individualized glioma therapy. To address the biological characteristics of circRNAs and their potential to induce resistance to TMZ, this review has highlighted and summarized the possible roles that circRNAs may play in molecular pathways of drug resistance, including the Ras/Raf/ERK PI3K/Akt signaling pathway and metabolic processes in gliomas.

Metabolic reprogramming and renal fibrosis: what role might Chinese medicine play?

Metabolic reprogramming is a pivotal biological process in which cellular metabolic patterns change to meet the energy demands of increased cell growth and proliferation. In this review, we explore metabolic reprogramming and its impact on fibrotic diseases, providing a detailed overview of the key processes involved in the metabolic reprogramming of renal fibrosis, including fatty acid decomposition and synthesis, glycolysis, and amino acid catabolism. In addition, we report that Chinese medicine ameliorates renal inflammation, oxidative stress, and apoptosis in chronic kidney disease by regulating metabolic processes, thereby inhibiting renal fibrosis. Furthermore, we reveal that multiple targets and signaling pathways contribute to the metabolic regulatory effects of Chinese medicine. In summary, this review aims to elucidate the mechanisms by which Chinese medicine inhibits renal fibrosis through the remodeling of renal cell metabolic processes, with the goal of discovering new therapeutic drugs for treating renal fibrosis.

2D co-culture model reveals a biophysical interplay between activated fibroblasts and cancer cells

The tumor microenvironment (TME) comprises diverse cell types within an altered extracellular matrix (ECM) and plays a pivotal role in metastasis through intricate cell-cell and cell-ECM interactions. Fibroblasts, as key constituents of the TME, contribute significantly to cancer metastasis through their involvement in matrix deposition and remodeling mechanisms, modulated by their quiescent or activated states. Despite their recognized importance, the precise role of fibroblasts in cancer cell invasion remains incompletely understood. In this study, we investigated the impact of fibroblast activity on cancer cell progression using a 2D co-culture model. Michigan Cancer Foundation-7 (MCF7) breast cancer cells were co-cultured with normal human lung fibroblasts (NHLF), both with and without transforming growth factor β (TGFβ) treatment. Traction force microscopy (TFM) was employed to quantify traction and velocity forces associated with cellular migration. We observed that TGFβ-activated fibroblasts form a distinctive ring around cancer cells in co-culture, with increased traction and tension at the cell island boundary. This force distribution is associated with the localization of force-related proteins at these boundary regions, including vinculin and E-cadherin. Metabolic profiling revealed a strong OXPHOS signal specific to the activated fibroblasts, in contrast to normal fibroblasts, which primarily display migratory behavior and a more heterogeneous pattern of forces and metabolic activity in co-culture. Our findings offer valuable insights into the mechanical forces and metabolic dynamics governing cellular migration in the tumor microenvironment, where our co-culture model could complement in vivo studies and enable researchers to explore specific microenvironmental cues for a deeper understanding of TME mechanisms. STATEMENT OF SIGNIFICANCE: Cancer models mimicking the dynamics of tumor microenvironment (TME) are an ideal tool to study cancer mechanisms and treatment. However, the full understanding of how cancer cells interact with their surroundings and other cells is still unknown. To tackle this, we developed a simple yet effective 2D co-culture model that allows us to control the arrangement of cell cultures precisely and use various imaging techniques to study interactions between cancer cells and fibroblasts. Here we could measure cell movements, force distribution, metabolic activity, and protein localization and interplay those factors in vitro. Our model helps us observe the underlying mechanisms between cancer cells and fibroblasts, contributing to our understanding of the dynamics in the TME.

Metabolic Reprogramming in Cancer: Implications for Immunosuppressive Microenvironment

Cancer is a complex and heterogeneous disease characterised by uncontrolled cell growth and proliferation. One hallmark of cancer cells is their ability to undergo metabolic reprogramming, which allows them to sustain their rapid growth and survival. This metabolic reprogramming creates an immunosuppressive microenvironment that facilitates tumour progression and evasion of the immune system. In this article, we review the mechanisms underlying metabolic reprogramming in cancer cells and discuss how these metabolic alterations contribute to the establishment of an immunosuppressive microenvironment. We also explore potential therapeutic strategies targeting metabolic vulnerabilities in cancer cells to enhance immune-mediated anti-tumour responses. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02044861, NCT03163667, NCT04265534, NCT02071927, NCT02903914, NCT03314935, NCT03361228, NCT03048500, NCT03311308, NCT03800602, NCT04414540, NCT02771626, NCT03994744, NCT03229278, NCT04899921.

SUMOylation regulates the aggressiveness of breast cancer-associated fibroblasts

BACKGROUND

Cancer-associated fibroblasts (CAFs) are the most abundant stromal cellular component in the tumor microenvironment (TME). CAFs contribute to tumorigenesis and have been proposed as targets for anticancer therapies. Similarly, dysregulation of SUMO machinery components can disrupt the balance of SUMOylation, contributing to tumorigenesis and drug resistance in various cancers, including breast cancer. We explored the role of SUMOylation in breast CAFs and evaluated its potential as a therapeutic strategy in breast cancer.

METHODS

We used pharmacological and genetic approaches to analyse the functional crosstalk between breast tumor cells and CAFs. We treated breast CAFs with the SUMO1 inhibitor ginkgolic acid (GA) at two different concentrations and conditioned media was used to analyse the proliferation, migration, and invasion of breast cancer cells from different molecular subtypes. Additionally, we performed quantitative proteomics (SILAC) to study the differential signalling pathways expressed in CAFs treated with low or high concentrations of GA. We confirmed these results both in vitro and in vivo. Moreover, we used samples from metastatic breast cancer patients to evaluate the use of GA as a therapeutic strategy.

RESULTS

Inhibition of SUMOylation with ginkgolic acid (GA) induces death in breast cancer cells but does not affect the viability of CAFs, indicating that CAFs are resistant to this therapy. While CAF viability is unaffected, CAF-conditioned media (CM) is altered by GA, impacting tumor cell behaviour in different ways depending on the overall degree to which SUMO1-SUMOylated proteins are dysregulated. Breast cancer cell lines exhibited a concentration-dependent response to conditioned media (CM) from CAFs. At a low concentration of GA (10 µM), there was an increase in proliferation, migration and invasion of breast cancer cells. However, at a higher concentration of GA (30 µM), these processes were inhibited. Similarly, analysis of tumor development revealed that at 10 µM of GA, the tumors were heavier and there was a greater degree of metastasis compared to the tumors treated with the higher concentration of GA (30 µM). Moreover, some of these effects could be explained by an alteration in the activity of the GTPase Rac1 and the activation of the AKT signalling pathway. The results obtained using SILAC suggest that different concentrations of GA affected cellular processes differentially, possibly influencing the secretome of CAFs. Treatment of metastatic breast cancer with GA demonstrated the use of SUMOylation inhibition as an alternative therapeutic strategy.

CONCLUSION

The study highlights the importance of SUMOylation in the tumor microenvironment, specifically in cancer-associated fibroblasts (CAFs). Targeting SUMOylation in CAFs affects their signalling pathways and secretome in a concentration-dependent manner, regulating the protumorigenic properties of CAFs.

Integration of ubiquitination-related genes in predictive signatures for prognosis and immunotherapy response in sarcoma

Background

Ubiquitination is one of the most prevalent and complex post-translational modifications of proteins in eukaryotes, playing a critical role in regulating various physiological and pathological processes. Targeting ubiquitination pathways, either through inhibition or activation, holds promise as a novel therapeutic approach for cancer treatment. However, the expression patterns, prognostic significance, and underlying mechanisms of ubiquitination-related genes (URGs) in sarcoma (SARC) remain unclear.

Methods

We analyzed URG expression patterns and prognostic implications in TCGA-SARC using public databases, identifying DEGs related to ubiquitination among SARC molecular subtypes. Functional enrichment analysis elucidated their biological significance. Prognostic signatures were developed using LASSO-Cox regression, and a predictive nomogram was constructed. External validation was performed using GEO datasets and clinical tissue samples. The association between URG risk scores and various clinical parameters, immune response, drug sensitivity, and RNA modification regulators was investigated. Integration of data from multiple sources and RT-qPCR confirmed upregulated expression of prognostic URGs in SARC. Single-cell RNA sequencing data analyzed URG distribution across immune cell types. Prediction analysis identified potential target genes of microRNAs and long non-coding RNAs.

Results

We identified five valuable genes (CALR, CASP3, BCL10, PSMD7, PSMD10) and constructed a prognostic model, simultaneously identifying two URG-related subtypes in SARC. The UEGs between subtypes in SARC are mainly enriched in pathways such as Cell cycle, focal adhesion, and ECM-receptor interaction. Analysis of URG risk scores reveals that patients with a low-risk score have better prognoses compared to those with high-risk scores. There is a significant correlation between DRG riskscore and clinical features, immune therapy response, drug sensitivity, and genes related to pan-RNA epigenetic modifications. High-risk SARC patients were identified as potential beneficiaries of immune checkpoint inhibitor therapy. We established regulatory axes in SARC, including CALR/hsa-miR-29c-3p/LINC00943, CASP3/hsa-miR-143-3p/LINC00944, and MIR503HG. RT-qPCR data further confirmed the upregulation of prognostic URGs in SARC. Finally, we validated the prognostic model's excellent predictive performance in predicting outcomes for SARC patients.

Conclusion

We discovered a significant correlation between aberrant expression of URGs and prognosis in SARC patients, identifying a prognostic model related to ubiquitination. This model provides a basis for individualized treatment and immunotherapy decisions for SARC patients.

Tumor hypoxia unveiled: insights into microenvironment, detection tools and emerging therapies

Hypoxia is one of the defining characteristics of the tumor microenvironment (TME) in solid cancers. It has a major impact on the growth and spread of malignant cells as well as their resistance to common treatments like radiation and chemotherapy. Here, we explore the complex functions of hypoxia in the TME and investigate its effects on angiogenesis, immunological evasion, and cancer cell metabolism. For prognostic and therapeutic reasons, hypoxia identification is critical, and recent developments in imaging and molecular methods have enhanced our capacity to precisely locate underoxygenated areas inside tumors. Furthermore, targeted therapies that take advantage of hypoxia provide a potential new direction in the treatment of cancer. Therapeutic approaches that specifically target hypoxic conditions in tumors without causing adverse effects are being led by hypoxia-targeted nanocarriers and hypoxia-activated prodrugs (HAPs). This review provides an extensive overview of this dynamic and clinically significant area of oncology research by synthesizing current knowledge about the mechanisms of hypoxia in cancer, highlighting state-of-the-art detection methodologies, and assessing the potential and efficacy of hypoxia-targeted therapies.

6-Phosphogluconate dehydrogenase promotes glycolysis and fatty acid synthesis by inhibiting the AMPK pathway in lung adenocarcinoma cells

Abnormal metabolism has emerged as a prominent hallmark of cancer and plays a pivotal role in carcinogenesis and progression of lung adenocarcinoma (LUAD). In this study, single-cell sequencing revealed that the metabolic enzyme 6-phosphogluconate dehydrogenase (PGD), which is a critical regulator of the pentose phosphate pathway (PPP), is significantly upregulated in the malignant epithelial cell subpopulation during malignant progression. However, the precise functional significance of PGD in LUAD and its underlying mechanisms remain elusive. Through the integration of TCGA database analysis and LUAD tissue microarray data, it was found that PGD expression was significantly upregulated in LUAD and closely correlated with a poor prognosis in LUAD patients. Moreover, in vitro and in vivo analyses demonstrated that PGD knockout and inhibition of its activity mitigated the proliferation, migration, and invasion of LUAD cells. Mechanistically, immunoprecipitation-mass spectrometry (IP-MS) revealed for the first time that IQGAP1 is a robust novel interacting protein of PGD. PGD decreased p-AMPK levels by competitively interacting with the IQ domain of the known AMPKα binding partner IQGAP1, which promoted glycolysis and fatty acid synthesis in LUAD cells. Furthermore, we demonstrated that the combination of Physcion (a PGD-specific inhibitor) and metformin (an AMPK agonist) could inhibit tumor growth more effectively both in vivo and in vitro. Collectively, these findings suggest that PGD is a potential prognostic biomarker and therapeutic target for LUAD.

Dissecting the roles of exosomal cancer-associated fibroblasts-derived non-coding RNAs in tumor progression: A complete guide

Cancer-associated fibroblasts are the most important cellular component of the tumor microenvironment, controlling cancer progression and therapeutic response. These cells in the tumor microenvironment regulate tumor progression and development as oncogenic or tumor suppressor agents. However, the mechanisms by which CAFs communicate with cancer cells remain to investigate. Here, we review evidence that extracellular vesicles, particularly exosomes, serve as vehicles for the intercellular transfer of bioactive cargos, notably microRNAs and long non-coding RNAs, from CAFs to cancer cells. We try to highlight molecular pathways of non-coding RNAs and the interaction among these molecules. Together, these findings elucidate a critical exosome-based communication axis by which CAFs create mostly a supportive pro-tumorigenic microenvironment and highlight therapeutic opportunities for disrupting this intercellular crosstalk.

EBF1-COX4I2 signaling axis promotes a myofibroblast-like phenotype in cancer-associated fibroblasts (CAFs) and is associated with an immunosuppressive microenvironment

Immunotherapy has limited response rates in colorectal cancer (CRC) due to an immunosuppressive tumor microenvironment (TME). Combining transcriptome sequencing, clinical specimens, and functional experiments, we identified a unique group of CAF subpopulations (COX4I2 + ) with inhibited mitochondrial respiration and enhanced glycolysis. Through bioinformatics predictions and luciferase reporter assays, we determined that EBF1 can upstreamly regulate COX4I2 transcription. COX4I2 + CAFs functionally and phenotypically resemble myofibroblasts, are important for the formation of the fibrotic TME, and are capable of activating the M2 phenotype of macrophages. In vitro experiments demonstrated that COX4I2 + CAFs promote immunosuppressive TME by blocking CD8 + T cell infiltration and inducing CD8 + T cell dysfunction. Using multiple independent cohorts, we also found a strong correlation between the immunotherapy response rate of CRC patients and COX4I2 expression in their tumors. Our results identify a CAF subpopulation characterized by activation of the EBF1-COX4I2 axis, and this group of CAFs can be targeted to improve cancer immunotherapy outcomes.

The MCIB Model: A Novel Theory for Describing the Spatial Heterogeneity of the Tumor Microenvironment

The tumor microenvironment (TME) can be regarded as a complex and dynamic microecosystem generated by the interactions of tumor cells, interstitial cells, the extracellular matrix, and their products and plays an important role in the occurrence, progression and metastasis of tumors. In a previous study, we constructed an IEO model (prI-, prE-, and pOst-metastatic niche) according to the chronological sequence of TME development. In this paper, to fill the theoretical gap in spatial heterogeneity in the TME, we defined an MCIB model (Metabolic, Circulatory, Immune, and microBial microenvironment). The MCIB model divides the TME into four subtypes that interact with each other in terms of mechanism, corresponding to the four major links of metabolic reprogramming, vascular remodeling, immune response, and microbial action, providing a new way to assess the TME. The combination of the MCIB model and IEO model comprehensively depicts the spatiotemporal evolution of the TME and can provide a theoretical basis for the combination of clinical targeted therapy, immunotherapy, and other comprehensive treatment modalities for tumors according to the combination and crosstalk of different subtypes in the MCIB model and provide a powerful research paradigm for tumor drug-resistance mechanisms and tumor biological behavior.

Metabolic and Immunological Implications of MME+CAF-Mediated Hypoxia Signaling in Pancreatic Cancer Progression: Therapeutic Insights and Translational Opportunities

Pancreatic cancer is a devastating malignancy with a high mortality rate, poor prognosis, and limited treatment options. The tumor microenvironment (TME) plays a crucial role in tumor progression and therapy resistance. Multiple subpopulations of cancer-associated fibroblasts (CAFs) within the TME can switch between different states, exhibiting both antitumorigenic and protumorigenic functions in pancreatic cancer. It seems that targeting fibroblast-related proteins and other stromal components is an appealing approach to combat pancreatic cancer. This study employed single-cell transcriptome sequencing to identify MME (Membrane Metalloendopeptidase)-expressing CAFs in pancreatic cancer. Systematic screening was conducted based on tumor differentiation, lymph node metastasis, and T-stage parameters to identify and confirm the existence of a subpopulation of fibroblasts termed MME+CAFs. Subsequent analyses included temporal studies, exploration of intercellular communication patterns focusing on the hypoxia signaling pathway, and investigation of MME+CAF functions in the pancreatic cancer microenvironment. The pathway enrichment analysis and clinical relevance revealed a strong association between high MME expression and glycolysis, hypoxia markers, and pro-cancer inflammatory pathways. The role of MME+CAFs was validated through in vivo and in vitro experiments, including high-throughput drug screening to evaluate potential targeted therapeutic strategies. Single-cell transcriptome sequencing revealed tumor-associated fibroblasts with high MME expression, termed MME+CAF, exhibiting a unique end-stage differentiation function in the TME. MME+CAF involvement in the hypoxia signaling pathway suggested the potential effects on pancreatic cancer progression through intercellular communication. High MME expression was associated with increased glycolysis, hypoxia markers (VEGF), and pro-cancer inflammatory pathways in pancreatic cancer patients, correlating with lower survival rates, advanced disease stage, and higher oncogene mutation rates. Animal experiments confirmed that elevated MME expression in CAFs increases tumor burden, promotes an immunosuppressive microenvironment, and enhances resistance to chemotherapy and immunotherapy. The developed MME+CAF inhibitor IOX2 (a specific prolyl hydroxylase-2 (PHD2) inhibitor), combined with AG (Paclitaxel + Gemcitabine) and anti-PD1 therapy, demonstrated promising antitumor effects, offering a translational strategy for targeting MME in CAFs of pancreatic cancer. The study findings highlighted the significant role of MME+CAF in pancreatic cancer progression by shaping the TME and influencing key pathways. Targeting MME presented a promising strategy to combat the disease, with potential implications for therapeutic interventions aimed at disrupting MME+CAF functions and enhancing the efficacy of pancreatic cancer treatments.

Pre-metastatic niche: formation, characteristics and therapeutic implication

Distant metastasis is a primary cause of mortality and contributes to poor surgical outcomes in cancer patients. Before the development of organ-specific metastasis, the formation of a pre-metastatic niche is pivotal in promoting the spread of cancer cells. This review delves into the intricate landscape of the pre-metastatic niche, focusing on the roles of tumor-derived secreted factors, extracellular vesicles, and circulating tumor cells in shaping the metastatic niche. The discussion encompasses cellular elements such as macrophages, neutrophils, bone marrow-derived suppressive cells, and T/B cells, in addition to molecular factors like secreted substances from tumors and extracellular vesicles, within the framework of pre-metastatic niche formation. Insights into the temporal mechanisms of pre-metastatic niche formation such as epithelial-mesenchymal transition, immunosuppression, extracellular matrix remodeling, metabolic reprogramming, vascular permeability and angiogenesis are provided. Furthermore, the landscape of pre-metastatic niche in different metastatic organs like lymph nodes, lungs, liver, brain, and bones is elucidated. Therapeutic approaches targeting the cellular and molecular components of pre-metastatic niche, as well as interventions targeting signaling pathways such as the TGF-β, VEGF, and MET pathways, are highlighted. This review aims to enhance our understanding of pre-metastatic niche dynamics and provide insights for developing effective therapeutic strategies to combat tumor metastasis.

A cancer-associated fibroblasts related risk score (CAFscore) helps to guide prognosis and personal treatment for Glioblastoma

BACKGROUND

Recent studies have identified the presence of cancer-associated fibroblasts (CAFs) within glioblastoma (GBM), yet their biological roles and underlying mechanisms remain poorly understood. This study aimed to construct a CAF-related prognostic model to guide patient prognosis and treatment strategies.

METHOD

We employed various bioinformatics methods, including enrichment analysis, Weighted Gene Co-expression Network Analysis (WGCNA), Lasso regression analysis, and machine learning techniques such as XGBoost and Random Forest, to develop a novel risk index termed CAFscore. Patients were stratified into high and low CAFscore groups for subsequent survival analysis. The area under the curve (AUC) and concordance index (C-index) for CAFscore were calculated and compared against other clinical characteristics and existing prognostic models. Drug sensitivity assessments were conducted using the Oncopredict package. Functional validation of key genes was performed through scratch and invasion assays in GBM cells.

RESULTS

Our analyses revealed four core CAF-related genes, leading to the establishment of CAFscore. Notably, patients in the high CAFscore group exhibited significantly reduced survival and exhibited enrichment in epithelial-mesenchymal transition (EMT) and inflammation response pathways. Furthermore, CAFscore showed a significant negative correlation with the sensitivity to irinotecan and its analogs, while demonstrating a positive correlation with sensitivity to 505,124 (a TGFβRI inhibitor). LRP10 emerged as a central gene within the CAFscore, displaying markedly elevated expression in GBM and a strong association with CAF infiltration. Silencing LRP10 significantly inhibited the invasive capabilities of GBM cells.

CONCLUSION

This study presented the first CAF related prognostic model (CAFscore) in GBM, and demonstrated that the model could effectively guide patient prognosis and potentially inform personalized treatment strategies. The core gene of CAFscore, LRP10, was significantly overexpressed in GBM and might play a pivotal role in regulating CAF infiltration as well as tumor invasion and metastasis, highlighting LRP10 as a promising therapeutic target for GBM management.

The multifaceted role of the stroma in the healthy prostate and prostate cancer

Prostate cancer (PC) is an age-related disease and represents, after lung cancer, the second cause of cancer death in males worldwide. Mortality is due to the metastatic disease, which mainly involves the bones, lungs, and liver. In the last 20 years, the incidence of metastatic PC has increased in Western Countries, and a further increase is expected in the near future, due to the population ageing. Current treatment options, including state of the art cancer immunotherapy, need to be more effective to achieve long-term disease control. The most significant anatomical barrier to overcome to improve the effectiveness of current and newly designed drug strategies consists of the prostatic stroma, in particular the fibroblasts and the extracellular matrix, which are the most abundant components of both the normal and tumor prostatic microenvironment. By weaving a complex communication network with the glandular epithelium, the immune cells, the microbiota, the endothelium, and the nerves, in the healthy prostatic microenvironment, the fibroblasts and the extracellular matrix support organ development and homeostasis. However, during inflammation, ageing and prostate tumorigenesis, they undergo dramatic phenotypic and genotypic changes, which impact on tumor growth and progression and on the development of therapy resistance. Here, we focus on the characteristics and functions of the prostate associated fibroblasts and of the extracellular matrix in health and cancer. We emphasize their roles in shaping tumor behavior and the feasibility of manipulating and/or targeting these stromal components to overcome the limitations of current treatments and to improve precision medicine's chances of success.

Malic enzymes in cancer: Regulatory mechanisms, functions, and therapeutic implications

Malic enzymes (MEs) are metabolic enzymes that catalyze the oxidation of malate to pyruvate and NAD(P)H. While researchers have well established the physiological metabolic roles of MEs in organisms, recent research has revealed a link between MEs and carcinogenesis. This review collates evidence of the molecular mechanisms by which MEs promote cancer occurrence, including transcriptional regulation, post-transcriptional regulation, post-translational protein modifications, and protein-protein interactions. Additionally, we highlight the roles of MEs in reprogramming energy metabolism, suppressing senescence, and modulating the tumor immune microenvironment. We also discuss the involvement of these enzymes in mediating tumor resistance and how the development of novel small-molecule inhibitors targeting MEs might be a good therapeutic approach. Insights through this review are expected to provide a comprehensive understanding of the intricate relationship between MEs and cancer, while facilitating future research on the potential therapeutic applications of targeting MEs in cancer management.

Unlocking the potential: Targeting metabolic pathways in the tumor microenvironment for Cancer therapy

Cancer incidence and mortality are increasing and impacting global life expectancy. Metabolic reprogramming in the tumor microenvironment (TME) is intimately related to tumorigenesis, progression, metastasis and drug resistance. Tumor cells drive metabolic reprogramming of other cells in the TME through metabolic induction of cytokines and metabolites, and metabolic substrate competition. Consequently, this boosts tumor cell growth by providing metabolic support and facilitating immunosuppression and angiogenesis. The metabolic interplay in the TME presents potential therapeutic targets. Here, we focus on the metabolic reprogramming of four principal cell subsets in the TME: CAFs, TAMs, TILs and TECs, and their interaction with tumor cells. We also summarize medications and therapies targeting these cells' metabolic pathways, particularly in the context of immune checkpoint blockade therapy.

Immunotherapy and the ovarian cancer microenvironment: Exploring potential strategies for enhanced treatment efficacy

Despite progress in cancer immunotherapy, ovarian cancer (OC) prognosis continues to be disappointing. Recent studies have shed light on how not just tumour cells, but also the complex tumour microenvironment, contribute to this unfavourable outcome of OC immunotherapy. The complexities of the immune microenvironment categorize OC as a 'cold tumour'. Nonetheless, understanding the precise mechanisms through which the microenvironment influences the effectiveness of OC immunotherapy remains an ongoing scientific endeavour. This review primarily aims to dissect the inherent characteristics and behaviours of diverse cells within the immune microenvironment, along with an exploration into its reprogramming and metabolic changes. It is expected that these insights will elucidate the operational dynamics of the immune microenvironment in OC and lay a theoretical groundwork for improving the efficacy of immunotherapy in OC management.

The heterogeneity of cellular metabolism in the tumour microenvironment of hepatocellular carcinoma with portal vein tumour thrombus

Given the growing interest in the metabolic heterogeneity of hepatocellular carcinoma (HCC) and portal vein tumour thrombus (PVTT). This study comprehensively analysed the metabolic heterogeneity of HCC, PVTT, and normal liver samples using multi-omics combinations. A single-cell RNA sequencing dataset encompassing six major cell types was obtained for integrated analysis. The optimal subtypes were identified using cluster stratification and validated using spatial transcriptomics and fluorescent multiplex immunohistochemistry. Then, a combined index based meta-cluster was calculated to verify its prognostic significance using multi-omics data from public cohorts. Our study first depicted the metabolic heterogeneity landscape of non-malignant cells in HCC and PVTT at multiomics levels. The optimal subtypes interpret the metabolic characteristics of PVTT formation and development. The combined index provided effective predictions of prognosis and immunotherapy responses. Patients with a higher combined index had a relatively poor prognosis (p <0.001). We also found metabolism of polyamines was a key metabolic pathway involved in conversion of metabolic heterogeneity in HCC and PVTT, and identified ODC1 was significantly higher expressed in PVTT compared to normal tissue (p =0.03). Our findings revealed both consistency and heterogeneity in the metabolism of non-malignant cells in HCC and PVTT. The risk stratification based on cancer-associated fibroblasts and myeloid cells conduce to predict prognosis and guide treatment. This offers new directions for understanding disease development and immunotherapy responses.

The molecular conversations of sarcomas: exosomal non-coding RNAs in tumor's biology and their translational prospects

Exosomes mediate cell-to-cell crosstalk involving a variety of biomolecules through an intricate signaling network. In recent years, the pivotal role of exosomes and their non-coding RNAs cargo in the development and progression of several cancer types clearly emerged. In particular, tumor bulk and its microenvironment co-evolve through cellular communications where these nanosized extracellular vesicles are among the most relevant actors. Knowledge about the cellular, and molecular mechanisms involved in these communications will pave the way for novel exosome-based delivery of therapeutic RNAs as well as innovative prognostic/diagnostic tools. Despite the valuable therapeutic potential and clinical relevance of exosomes, their role on sarcoma has been vaguely reported because the rarity and high heterogeneity of this type of cancer. Here, we dissected the scientific literature to unravel the multifaceted role of exosomal non-coding RNAs as mediator of cell-to-cell communications in the sarcoma subtypes.

Lipid metabolism associated crosstalk: the bidirectional interaction between cancer cells and immune/stromal cells within the tumor microenvironment for prognostic insight

Cancer is closely related to lipid metabolism, with the tumor microenvironment (TME) containing numerous lipid metabolic interactions. Cancer cells can bidirectionally interact with immune and stromal cells, the major components of the TME. This interaction is primarily mediated by fatty acids (FAs), cholesterol, and phospholipids. These interactions can lead to various physiological changes, including immune suppression, cancer cell proliferation, dissemination, and anti-apoptotic effects on cancer cells. The physiological modulation resulting from this lipid metabolism-associated crosstalk between cancer cells and immune/stromal cells provides valuable insights into cancer prognosis. A comprehensive literature review was conducted to examine the function of the bidirectional lipid metabolism interactions between cancer cells and immune/stromal cells within the TME, particularly how these interactions influence cancer prognosis. A novel autophagy-extracellular vesicle (EV) pathway has been proposed as a mediator of lipid metabolism interactions between cancer cells and immune cells/stromal cells, impacting cancer prognosis. As a result, different forms of lipid metabolism interactions have been described as being linked to cancer prognosis, including those mediated by the autophagy-EV pathway. In conclusion, understanding the bidirectional lipid metabolism interactions between cancer cells and stromal/immune cells in the TME can help develop more advanced prognostic approaches for cancer patients.

Cancer-associated fibroblasts mediate resistance to anti-EGFR therapies in cancer

Over the last decade, epidermal growth factor receptor (EGFR)-targeted therapies have transformed the treatment landscape for patients with advanced solid tumors. Despite these advances, resistance to anti-EGFR therapies is still a significant clinical challenge. While cell-autonomous mechanisms of resistance are well-documented, they do not fully elucidate the complexity of drug resistance. Cancer-associated fibroblasts (CAFs), key mediators within the tumor microenvironment (TME), have emerged as pivotal players in cancer progression and chemoresistance. Recent evidence implicates CAFs in resistance to anti-EGFR therapies, suggesting they may undermine treatment efficacy. This review synthesizes current data, highlighting the critical role of CAFs in resistance pathogenesis and summarizing recent therapeutic strategies targeting CAFs. We underscore the challenges and advocate for the exploration of CAFs as a potential dual-targeted approach.

Endogenous activation of peroxisome proliferator-activated receptor-α in proximal tubule cells in counteracting phosphate toxicity

Increased dietary phosphate consumption intensifies renal phosphate burden. Several mechanisms for phosphate-induced renal tubulointerstitial fibrosis have been reported. Considering the dual nature of phosphate as both a potential renal toxin and an essential nutrient for the body, kidneys may possess inherent protective mechanisms against phosphate overload, rather than succumbing solely to injury. However, there is limited understanding of such mechanisms. To identify these mechanisms, we conducted single-cell RNA sequencing (scRNA-seq) analysis of the kidneys of control and dietary phosphate-loaded (Phos) mice at a time point when the Phos group had not yet developed tubulointerstitial fibrosis. scRNA-seq analysis identified the highest number of differentially expressed genes in the clusters belonging to proximal tubular epithelial cells (PTECs). Based on these differentially expressed genes, in silico analyses suggested that the Phos group activated peroxisome proliferator-activated receptor-α (PPAR-α) and fatty acid β-oxidation (FAO) in the PTECs. This activation was further substantiated through various experiments, including the use of an FAO activity visualization probe. Compared with wild-type mice, Ppara knockout mice exhibited exacerbated tubulointerstitial fibrosis in response to phosphate overload. Experiments conducted with cultured PTECs demonstrated that activation of the PPAR-α/FAO pathway leads to improved cellular viability under high-phosphate conditions. The Phos group mice showed a decreased serum concentration of free fatty acids, which are endogenous PPAR-α agonists. Instead, experiments using cultured PTECs revealed that phosphate directly activates the PPAR-α/FAO pathway. These findings indicate that noncanonical metabolic reprogramming via endogenous activation of the PPAR-α/FAO pathway in PTECs is essential to counteract phosphate toxicity.NEW & NOTEWORTHY This study revealed the activation of peroxisome proliferator-activated receptor-α and fatty acid β-oxidation in proximal tubular epithelial cells as an endogenous mechanism to protect the kidney from phosphate toxicity. These findings highlight noncanonical metabolic reprogramming as a potential target for suppressing phosphate toxicity in the kidneys.

The role of cancer-associated fibroblasts in the invasion and metastasis of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer and has ranked the third leading cause in cancerassociated death globally. Metastasis is the leading cause of death in colorectal cancer patients. The role of tumor microenvironment (TME) in colorectal cancer metastasis has received increasing attention. As the most abundant cell type in the TME of solid tumors, cancer-associated fibroblasts (CAFs) have been demonstrated to have multiple functions in advancing tumor growth and metastasis. They can remodel the extracellular matrix (ECM) architecture, promote epithelial-mesenchymal transition (EMT), and interact with cancer cells or other stromal cells by secreting growth factors, cytokines, chemokines, and exosomes, facilitating tumor cell invasion into TME and contributing to distant metastasis. This article aims to analyze the sources and heterogeneity of CAFs in CRC, as well as their role in invasion and metastasis, in order to provide new insights into the metastasis mechanism of CRC and its clinical applications.

Advances in targeting cancer-associated fibroblasts through single-cell spatial transcriptomic sequencing

Cancer-associated fibroblasts (CAFs) are the major components of the tumor microenvironment and are related to tumor proliferation, metastasis, relapse, and drug resistance. With the development of sequencing technologies, single-cell RNA sequencing has become a popular method for identifying CAFs in the tumor microenvironment. Whereas the drawbacks of CAFs, such as the lack of a spatial landscape, still exist, recent research has utilized spatial transcriptomics combined with single-cell RNA sequencing to address this issue. These multiomics analyses can resolve the single-cell resolution problem in spatial transcriptomics. In this review, we summarized the recent literature regarding the targeting of CAFs to address drug resistance, angiogenesis, metabolic reprogramming and metastasis in tumor tissue.

Roles of Lysine Methylation in Glucose and Lipid Metabolism: Functions, Regulatory Mechanisms, and Therapeutic Implications

Glucose and lipid metabolism are essential energy sources for the body. Dysregulation in these metabolic pathways is a significant risk factor for numerous acute and chronic diseases, including type 2 diabetes (T2DM), Alzheimer's disease (AD), obesity, and cancer. Post-translational modifications (PTMs), which regulate protein structure, localization, function, and activity, play a crucial role in managing cellular glucose and lipid metabolism. Among these PTMs, lysine methylation stands out as a key dynamic modification vital for the epigenetic regulation of gene transcription. Emerging evidence indicates that lysine methylation significantly impacts glucose and lipid metabolism by modifying key enzymes and proteins. This review summarizes the current understanding of lysine methylation's role and regulatory mechanisms in glucose and lipid metabolism. We highlight the involvement of methyltransferases (KMTs) and demethylases (KDMs) in generating abnormal methylation signals affecting these metabolic pathways. Additionally, we discuss the chemical biology and pharmacology of KMT and KDM inhibitors and targeted protein degraders, emphasizing their clinical implications for diseases such as diabetes, obesity, neurodegenerative disorders, and cancers. This review suggests that targeting lysine methylation in glucose and lipid metabolism could be an ideal therapeutic strategy for treating these diseases.

Single-cell RNA sequencing in ovarian cancer: revealing new perspectives in the tumor microenvironment

Single-cell sequencing technology has emerged as a pivotal tool for unraveling the complexities of the ovarian tumor microenvironment (TME), which is characterized by its cellular heterogeneity and intricate cell-to-cell interactions. Ovarian cancer (OC), known for its high lethality among gynecologic malignancies, presents significant challenges in treatment and diagnosis, partly due to the complexity of its TME. The application of single-cell sequencing in ovarian cancer research has enabled the detailed characterization of gene expression profiles at the single-cell level, shedding light on the diverse cell populations within the TME, including cancer cells, stromal cells, and immune cells. This high-resolution mapping has been instrumental in understanding the roles of these cells in tumor progression, invasion, metastasis, and drug resistance. By providing insight into the signaling pathways and cell-to-cell communication mechanisms, single-cell sequencing facilitates the identification of novel therapeutic targets and the development of personalized medicine approaches. This review summarizes the advancement and application of single-cell sequencing in studying the stromal components and the broader TME in OC, highlighting its implications for improving diagnosis, treatment strategies, and understanding of the disease's underlying biology.

CCL2 and Lactate from Chemotherapeutics-Treated Fibroblasts Drive Malignant Traits by Metabolic Rewiring in Low-Migrating Breast Cancer Cell Lines

While cytostatic chemotherapy targeting DNA is known to induce genotoxicity, leading to cell cycle arrest and cytokine secretion, the impact of these drugs on fibroblast-epithelial cancer cell communication and metabolism remains understudied. Our research focused on human breast fibroblast RMF-621 exposed to nonlethal concentrations of cisplatin and doxorubicin, revealing reduced proliferation, diminished basal and maximal mitochondrial respirations, heightened mitochondrial ROS and lactate production, and elevated MCT4 protein levels. Interestingly, RMF-621 cells enhanced glucose uptake, promoting lactate export. Breast cancer cells MCF-7 exposed to conditioned media (CM) from drug-treated stromal RMF-621 cells increased MCT1 protein levels, lactate-driven mitochondrial respiration, and a significantly high mitochondrial spare capacity for lactate. These changes occurred alongside altered mitochondrial respiration, mitochondrial membrane potential, and superoxide levels. Furthermore, CM with doxorubicin and cisplatin increased migratory capacity in MCF-7 cells, which was inhibited by MCT1 (BAY-8002), glutamate dehydrogenase (EGCG), mitochondrial pyruvate carrier (UK5099), and complex I (rotenone) inhibitors. A similar behavior was observed in T47-D and ZR-75-1 breast cancer cells. This suggests that CM induces metabolic rewiring involving elevated lactate uptake to sustain mitochondrial bioenergetics during migration. Treatment with the mitochondrial-targeting antioxidant mitoTEMPO in RMF-621 and the addition of an anti-CCL2 antibody in the CM prevented the promigratory MCF-7 phenotype. Similar effects were observed in THP1 monocyte cells, where CM increased monocyte recruitment. We propose that nonlethal concentrations of DNA-damaging drugs induce changes in the cellular environment favoring a promalignant state dependent on mitochondrial bioenergetics.

Hydrogen Therapy Reverses Cancer-Associated Fibroblasts Phenotypes and Remodels Stromal Microenvironment to Stimulate Systematic Anti-Tumor Immunity

Tumor microenvironment (TME) plays an important role in the tumor progression. Among TME components, cancer-associated fibroblasts (CAFs) show multiple tumor-promoting effects and can induce tumor immune evasion and drug-resistance. Regulating CAFs can be a potential strategy to augment systemic anti-tumor immunity. Here, the study observes that hydrogen treatment can alleviate intracellular reactive oxygen species of CAFs and reshape CAFs' tumor-promoting and immune-suppressive phenotypes. Accordingly, a controllable and TME-responsive hydrogen therapy based on a CaCO3 nanoparticles-coated magnesium system (Mg-CaCO3) is developed. The hydrogen therapy by Mg-CaCO3 can not only directly kill tumor cells, but also inhibit pro-tumor and immune suppressive factors in CAFs, and thus augment immune activities of CD4+ T cells. As implanted in situ, Mg-CaCO3 can significantly suppress tumor growth, turn the "cold" primary tumor into "hot", and stimulate systematic anti-tumor immunity, which is confirmed by the bilateral tumor transplantation models of "cold tumor" (4T1 cells) and "hot tumor" (MC38 cells). This hydrogen therapy system reverses immune suppressive phenotypes of CAFs, thus providing a systematic anti-tumor immune stimulating strategy by remodeling tumor stromal microenvironment.

FTO elicits tumor neovascularization in cancer-associated fibroblasts through eliminating m6A modifications of multiple pro-angiogenic factors

Cancer-associated fibroblasts (CAFs) exhibit notable versatility, plasticity, and robustness, actively participating in cancer progression through intricate interactions within the tumor microenvironment (TME). N6-methyladenosine (m6A) modification is the most prevalent modification in eukaryotic mRNA, playing essential roles in mRNA metabolism and various biological processes. Howbeit, the precise involvement of m6A in CAF activation remains enigmatic. In this study, we revealed that the m6A demethylase FTO supports CAF-mediated angiogenesis through activation of EGR1 and VEGFA in conjunctival melanoma (CoM). First, single-cell transcriptome analysis revealed that FTO was specifically upregulated in the CAF population, thereby contributing to the hypo-m6A status in the TME of CoM. Moreover, CAFs of CoM displayed extensive proangiogenic potential, which was largely compromised by FTO inhibition, both in vitro and in vivo. By employing multi-omics analysis, we showed that FTO effectively eliminates the m6A modifications of VEGFA and EGR1. This process subsequently disrupts the YTHDF2-dependent mRNA decay pathway, resulting in increased mRNA stability and upregulated expression of these molecules. Collectively, our findings initially indicate that the upregulation of FTO plays a pivotal role in tumor development by promoting CAF-mediated angiogenesis. Therapeutically, targeting FTO may show promise as a potential antiangiogenic strategy to optimize cancer treatment.

Unraveling the intricacies of cancer-associated fibroblasts: a comprehensive review on metabolic reprogramming and tumor microenvironment crosstalk

Cancer-associated fibroblasts (CAFs) are crucial component of tumor microenvironment (TME) which undergo significant phenotypic changes and metabolic reprogramming, profoundly impacting tumor growth. This review delves into CAF plasticity, diverse origins, and the molecular mechanisms driving their continuous activation. Emphasis is placed on the intricate bidirectional crosstalk between CAFs and tumor cells, promoting cancer cell survival, proliferation, invasion, and immune evasion. Metabolic reprogramming, a cancer hallmark, extends beyond cancer cells to CAFs, contributing to the complex metabolic interplay within the TME. The 'reverse Warburg effect' in CAFs mirrors the Warburg effect, involving the export of high-energy substrates to fuel cancer cells, supporting their rapid proliferation. Molecular regulations by key players like p53, Myc, and K-RAS orchestrate this metabolic adaptation. Understanding the metabolic symbiosis between CAFs and tumor cells opens avenues for targeted therapeutic strategies to disrupt this dynamic crosstalk. Unraveling CAF-mediated metabolic reprogramming provides valuable insights for developing novel anticancer therapies. This comprehensive review consolidates current knowledge, shedding light on CAFs' multifaceted roles in the TME and offering potential targets for future therapies.

Cancer-associated fibroblasts: heterogeneity and their role in the tumor immune response

In recent decades, many reports have been published on the composition and function of the tumor microenvironment (TME), among which cancer-associated fibroblasts (CAFs) have received much attention. CAFs have different degrees of heterogeneity in terms of their origin, phenotype, and function and can be divided into different subpopulations. These subgroups may play different roles in the occurrence and development of tumors. In addition, CAFs are closely associated with tumor immunity and have been found to regulate immune cell activity and to suppress the tumor immune response. In this review, we systematize the heterogeneity and characteristics of CAFs, discuss how specific CAF subgroups contribute to cancer progression by inducing an immunosuppressive microenvironment, and finally, we examine the future clinical applications of CAF subgroups.

miR-200-mediated inactivation of cancer-associated fibroblasts via targeting of NRP2-VEGFR signaling attenuates lung cancer invasion and metastasis

Cancer-associated fibroblasts (CAFs) play a substantial role in promoting cancer cell motility, drug resistance, angiogenesis, and metastasis; therefore, extensive research has been conducted to determine their mode of activation. We aimed to identify whether miRNA-200 (miR-200), a widely recognized suppressor of epithelial-mesenchymal transition, prevents CAFs from promoting cancer progression. Overexpression of miR-200 prevented CAFs from promoting lung cancer cell migration, invasion, tumorigenicity, and metastasis. Additionally, miR-200 suppressed the ability of CAFs to recruit and polarize macrophages toward the M2 phenotype, as well as the migration and tube formation of vascular endothelial cells. NRP2, a co-receptor of vascular endothelial growth factor receptor (VEGFR), was confirmed to be a target of miR-200, which mediates the functional activity of miR-200 in CAFs. NRP2-VEGFR signaling facilitates the secretion of VEGF-D and pleiotrophin from CAFs, leading to the activation of cancer cell migration and invasion. These findings suggest that miR-200 remodels CAFs to impede cancer progression and metastasis and that miR-200 and NRP2 are potential therapeutic targets in the treatment of lung cancer.

Metabolic Reprogramming in Thyroid Cancer

Thyroid cancer is a common endocrine malignancy with increasing incidence globally. Although most cases can be treated effectively, some cases are more aggressive and have a higher risk of mortality. Inhibiting RET and BRAF kinases has emerged as a potential therapeutic strategy for the treatment of thyroid cancer, particularly in cases of advanced or aggressive disease. However, the development of resistance mechanisms may limit the efficacy of these kinase inhibitors. Therefore, developing precise strategies to target thyroid cancer cell metabolism and overcome resistance is a critical area of research for advancing thyroid cancer treatment. In the field of cancer therapeutics, researchers have explored combinatorial strategies involving dual metabolic inhibition and metabolic inhibitors in combination with targeted therapy, chemotherapy, and immunotherapy to overcome the challenge of metabolic plasticity. This review highlights the need for new therapeutic approaches for thyroid cancer and discusses promising metabolic inhibitors targeting thyroid cancer. It also discusses the challenges posed by metabolic plasticity in the development of effective strategies for targeting cancer cell metabolism and explores the potential advantages of combined metabolic targeting.

Dendritic Polymer-Based Nanomedicines Remodel the Tumor Stroma: Improve Drug Penetration and Enhance Antitumor Immune Response

The dense extracellular matrix (ECM) in solid tumors, contributed by cancer-associated fibroblasts (CAFs), hinders penetration of drugs and diminishes their therapeutic outcomes. A sequential treatment strategy of remodeling the ECM via a CAF modifier (dasatinib, DAS) is proposed to promote penetration of an immunogenic cell death (ICD) inducer (epirubicin, Epi) via apoptotic vesicles, ultimately enhancing the treatment efficacy against breast cancer. Dendritic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA)-based nanomedicines (poly[OEGMA-Dendron(G2)-Gly-Phe-Leu-Gly-DAS] (P-DAS) and poly[OEGMA-Dendron(G2)-hydrazone-Epi] (P-Epi)) are developed for sequential delivery of DAS and Epi, respectively. P-DAS reprograms CAFs to reduce collagen by downregulating collagen anabolism and energy metabolism, thereby reducing the ECM deposition. The regulated ECM can enhance tumor penetration of P-Epi to strengthen its ICD effect, leading to an amplified antitumor immune response. In breast cancer-bearing mice, this approach alleviates the ECM barrier, resulting in reduced tumor burden and increased cytotoxic T lymphocyte infiltration, and more encouragingly, synergizes effectively with anti-programmed cell death 1 (PD-1) therapy, significantly inhibiting tumor growth and preventing lung metastasis. Furthermore, systemic toxicity is barely detectable after sequential treatment with P-DAS and P-Epi. This approach opens a new avenue for treating desmoplastic tumors by metabolically targeting CAFs to overcome the ECM barrier.

Metabolic heterogeneity in tumor microenvironment - A novel landmark for immunotherapy

The surrounding non-cancer cells and tumor cells that make up the tumor microenvironment (TME) have various metabolic rhythms. TME metabolic heterogeneity is influenced by the intricate network of metabolic control within and between cells. DNA, protein, transport, and microbial levels are important regulators of TME metabolic homeostasis. The effectiveness of immunotherapy is also closely correlated with alterations in TME metabolism. The response of a tumor patient to immunotherapy is influenced by a variety of variables, including intracellular metabolic reprogramming, metabolic interaction between cells, ecological changes within and between tumors, and general dietary preferences. Although immunotherapy and targeted therapy have made great strides, their use in the accurate identification and treatment of tumors still has several limitations. The function of TME metabolic heterogeneity in tumor immunotherapy is summarized in this article. It focuses on how metabolic heterogeneity develops and is regulated as a tumor progresses, the precise molecular mechanisms and potential clinical significance of imbalances in intracellular metabolic homeostasis and intercellular metabolic coupling and interaction, as well as the benefits and drawbacks of targeted metabolism used in conjunction with immunotherapy. This offers insightful knowledge and important implications for individualized tumor patient diagnosis and treatment plans in the future.

Time-dependent proteomics and drug response in expanding cancer cells

Cancer cell line is commonly used for discovery and development of anti-cancer drugs. It is generally considered that drug response remains constant for a certain cell line due to the identity of genetics thus protein patterns. Here, we demonstrated that cancer cells continued dividing even after reaching confluence, in that the proteomics was changed continuously and dramatically with strong relevance to cell division, cell adhesion and cell metabolism, indicating time-dependent intrinsically reprogramming of cells during expansion. Of note, the inhibition effect of most anti-cancer drugs was strikingly attenuated in culture cells along with cell expansion, with the strongest change at the third day when cells were still expanding. Profiling of an FDA-approved drug library revealed that attenuation of response with cell expansion is common for most drugs, an exception was TAK165 that was a selective inhibitor of mitochondrial respiratory chain complex I. Finally, we screened a panel of natural products and identified four pentacyclic triterpenes as selective inhibitors of cancer cells under prolonged growth. Taken together, our findings underscore that caution should be taken in evaluation of anti-cancer drugs using culture cells, and provide agents selectively targeting overgrowth cancer cells.

The PI3K/Akt Pathway and Glucose Metabolism: A Dangerous Liaison in Cancer

Aberrant activation of the PI3K/Akt pathway commonly occurs in cancers and correlates with multiple aspects of malignant progression. In particular, recent evidence suggests that the PI3K/Akt signaling plays a fundamental role in promoting the so-called aerobic glycolysis or Warburg effect, by phosphorylating different nutrient transporters and metabolic enzymes, such as GLUT1, HK2, PFKB3/4 and PKM2, and by regulating various molecular networks and proteins, including mTORC1, GSK3, FOXO transcription factors, MYC and HIF-1α. This leads to a profound reprogramming of cancer metabolism, also impacting on pentose phosphate pathway, mitochondrial oxidative phosphorylation, de novo lipid synthesis and redox homeostasis and thereby allowing the fulfillment of both the catabolic and anabolic demands of tumor cells. The present review discusses the interactions between the PI3K/Akt cascade and its metabolic targets, focusing on their possible therapeutic implications.

Proteomics of tumor and serum samples from isocitrate dehydrogenase-wildtype glioblastoma patients: is the detoxification of reactive oxygen species associated with shorter survival?

Proteomics has been little used for the identification of novel prognostic and/or therapeutic markers in isocitrate dehydrogenase (IDH)-wildtype glioblastoma (GB). In this study, we analyzed 50 tumor and 30 serum samples from short- and long-term survivors of IDH-wildtype GB (STS and LTS, respectively) by data-independent acquisition mass spectrometry (DIA-MS)-based proteomics, with the aim of identifying such markers. DIA-MS identified 5422 and 826 normalized proteins in tumor and serum samples, respectively, with only three tumor proteins and 26 serum proteins displaying significant differential expression between the STS and LTS groups. These dysregulated proteins were principally associated with the detoxification of reactive oxygen species (ROS). In particular, GB patients in the STS group had high serum levels of malate dehydrogenase 1 (MDH1) and ribonuclease inhibitor 1 (RNH1) and low tumor levels of fatty acid-binding protein 7 (FABP7), which may have enabled them to maintain low ROS levels, counteracting the effects of the first-line treatment with radiotherapy plus concomitant and adjuvant temozolomide. A blood score built on the levels of MDH1 and RNH1 expression was found to be an independent prognostic factor for survival based on the serum proteome data for a cohort of 96 IDH-wildtype GB patients. This study highlights the utility of circulating MDH1 and RNH1 biomarkers for determining the prognosis of patients with IDH-wildtype GB. Furthermore, the pathways driven by these biomarkers, and the tumor FABP7 pathway, may constitute promising therapeutic targets for blocking ROS detoxification to overcome resistance to chemoradiotherapy in potential GB STS.

Ovarian Cancer Cell-Conditioning Medium Induces Cancer-Associated Fibroblast Phenoconversion through Glucose-Dependent Inhibition of Autophagy

One aspect of ovarian tumorigenesis which is still poorly understood is the tumor-stroma interaction, which plays a major role in chemoresistance and tumor progression. Cancer-associated fibroblasts (CAFs), the most abundant stromal cell type in the tumor microenvironment, influence tumor growth, metabolism, metastasis, and response to therapy, making them attractive targets for anti-cancer treatment. Unraveling the mechanisms involved in CAFs activation and maintenance is therefore crucial for the improvement of therapy efficacy. Here, we report that CAFs phenoconversion relies on the glucose-dependent inhibition of autophagy. We show that ovarian cancer cell-conditioning medium induces a metabolic reprogramming towards the CAF-phenotype that requires the autophagy-dependent glycolytic shift. In fact, 2-deoxy-D-glucose (2DG) strongly hampers such phenoconversion and, most importantly, induces the phenoreversion of CAFs into quiescent fibroblasts. Moreover, pharmacological inhibition (by proline) or autophagy gene knockdown (by siBECN1 or siATG7) promotes, while autophagy induction (by either 2DG or rapamycin) counteracts, the metabolic rewiring induced by the ovarian cancer cell secretome. Notably, the nutraceutical resveratrol (RV), known to inhibit glucose metabolism and to induce autophagy, promotes the phenoreversion of CAFs into normal fibroblasts even in the presence of ovarian cancer cell-conditioning medium. Overall, our data support the view of testing autophagy inducers for targeting the tumor-promoting stroma as an adjuvant strategy to improve therapy success rates, especially for tumors with a highly desmoplastic stroma, like ovarian cancer.

Sphingolipids in prostate cancer prognosis: integrating single-cell and bulk sequencing

BACKGROUND

Stratifying patient risk and exploring the tumor microenvironment are critical endeavors in prostate cancer research, essential for advancing our understanding and management of this disease.

METHODS

Single-cell sequencing data for prostate cancer were sourced from the pradcellatlas website, while bulk transcriptome data were obtained from the TCGA database. Dimensionality reduction cluster analysis was employed to investigate heterogeneity in single-cell sequencing data. Gene set enrichment analysis, utilizing GO and KEGG pathways, was conducted to explore functional aspects. Weighted gene coexpression network analysis (WGCNA) identified key gene modules. Prognostic models were developed using Cox regression and LASSO regression techniques, implemented in R software. Validation of key gene expression levels was performed via PCR assays.

RESULTS

Through integrative analysis of single-cell and bulk transcriptome data, key genes implicated in prostate cancer pathogenesis were identified. A prognostic model focused on sphingolipid metabolism (SRSR) was constructed, comprising five genes: "FUS," "MARK3," "CHTOP," "ILF3," and "ARIH2." This model effectively stratified patients into high-risk and low-risk groups, with the high-risk cohort exhibiting significantly poorer prognoses. Furthermore, distinct differences in the immune microenvironment were observed between these groups. Validation of key gene expression, exemplified by ILF3, was confirmed through PCR analysis.

CONCLUSION

This study contributes to our understanding of the role of sphingolipid metabolism in prostate cancer diagnosis and treatment. The identified prognostic model holds promise for improving risk stratification and patient outcomes in clinical settings.

PRMT5 activates lipid metabolic reprogramming via MYC contributing to the growth and survival of mantle cell lymphoma

Mantle cell lymphoma (MCL) is an incurable and aggressive subtype of non-Hodgkin B-cell lymphoma. Increased lipid uptake, storage, and lipogenesis occur in a variety of cancers and contribute to rapid tumor growth. However, no data has been explored for the roles of lipid metabolism reprogramming in MCL. Here, we identified aberrant lipid metabolism reprogramming and PRMT5 as a key regulator of cholesterol and fatty acid metabolism reprogramming in MCL patients. High PRMT5 expression predicts adverse outcome prognosis in 105 patients with MCL and GEO database (GSE93291). PRMT5 deficiency resulted in proliferation defects and cell death by CRISPR/Cas9 editing. Moreover, PRMT5 inhibitors including SH3765 and EPZ015666 worked through blocking SREBP1/2 and FASN expression in MCL. Furthermore, PRMT5 was significantly associated with MYC expression in 105 MCL samples and the GEO database (GSE93291). CRISPR MYC knockout indicated PRMT5 can promote MCL outgrowth by inducing SREBP1/2 and FASN expression through the MYC pathway.

Cellular Trojan Horse initiates bimetallic Fe-Cu MOF-mediated synergistic cuproptosis and ferroptosis against malignancies

Disruptions in metal balance can trigger a synergistic interplay of cuproptosis and ferroptosis, offering promising solutions to enduring challenges in oncology. Here, we have engineered a Cellular Trojan Horse, named MetaCell, which uses live neutrophils to stably internalize thermosensitive liposomal bimetallic Fe-Cu MOFs (Lip@Fe-Cu-MOFs). MetaCell can instigate cuproptosis and ferroptosis, thereby enhancing treatment efficacy. Mirroring the characteristics of neutrophils, MetaCell can evade the immune system and not only infiltrate tumors but also respond to inflammation by releasing therapeutic components, thereby surmounting traditional treatment barriers. Notably, Lip@Fe-Cu-MOFs demonstrate notable photothermal effects, inciting a targeted release of Fe-Cu-MOFs within cancer cells and amplifying the synergistic action of cuproptosis and ferroptosis. MetaCell has demonstrated promising treatment outcomes in tumor-bearing mice, effectively eliminating solid tumors and forestalling recurrence, leading to extended survival. This research provides great insights into the complex interplay between copper and iron homeostasis in malignancies, potentially paving the way for innovative approaches in cancer treatment.

The Application of Nanoparticles Targeting Cancer-Associated Fibroblasts

Cancer-associated fibroblasts (CAF) are the most abundant stromal cells in the tumor microenvironment (TME), especially in solid tumors. It has been confirmed that it can not only interact with tumor cells to promote cancer progression and metastasis, but also affect the infiltration and function of immune cells to induce chemotherapy and immunotherapy resistance. So, targeting CAF has been considered an important method in cancer treatment. The rapid development of nanotechnology provides a good perspective to improve the efficiency of targeting CAF. At present, more and more researches have focused on the application of nanoparticles (NPs) in targeting CAF. These studies explored the effects of different types of NPs on CAF and the multifunctional nanomedicines that can eliminate CAF are able to enhance the EPR effect which facilitate the anti-tumor effect of themselves. There also exist amounts of studies focusing on using NPs to inhibit the activation and function of CAF to improve the therapeutic efficacy. The application of NPs targeting CAF needs to be based on an understanding of CAF biology. Therefore, in this review, we first summarized the latest progress of CAF biology, then discussed the types of CAF-targeting NPs and the main strategies in the current. The aim is to elucidate the application of NPs in targeting CAF and provide new insights for engineering nanomedicine to enhance immune response in cancer treatment.

Targeting the lipid metabolic reprogramming of tumor-associated macrophages: A novel insight into cancer immunotherapy

BACKGROUND

Tumor-associated macrophages, as the major immunocytes in solid tumors, show divided loyalty and remarkable plasticity in tumorigenesis. Once the M2-to-M1 repolarization is achieved, they could be switched from the supporters for tumor development into the guardians for host immunity. Meanwhile, Lipid metabolic reprogramming is demonstrated to be one of the most important hallmarks of tumor-associated macrophages, which plays a decisive role in regulating their phenotypes and functions to promote tumorigenesis and immunotherapy resistance. Therefore, targeting the lipid metabolism of TAMs may provide a new direction for anti-tumor strategies.

CONCLUSION

In this review, we first summarized the origins, classifications and general lipid metabolic process of TAMs. Then we discussed the currently available drugs and interventions that target lipid metabolic disorders of TAMs, including those targeting lipid uptake, efflux, lipolysis, FAO and lipid peroxidation. Besides, based on the recent research status, we summarized the present challenges for this cancer immunotherapy, including the precise drug delivery system, the lipid metabolic heterogeneity, and the intricate lipid metabolic interactions in the TME, and we also proposed corresponding possible solutions. Collectively, we hope this review will give researchers a better understanding of the lipid metabolism of TAMs and lead to the development of corresponding anti-tumor therapies in the future.

The rising roles of exosomes in the tumor microenvironment reprogramming and cancer immunotherapy

Exosomes are indispensable for intercellular communications. Tumor microenvironment (TME) is the living environment of tumor cells, which is composed of various components, including immune cells. Based on TME, immunotherapy has been recently developed for eradicating cancer cells by reactivating antitumor effect of immune cells. The communications between tumor cells and TME are crucial for tumor development, metastasis, and drug resistance. Exosomes play an important role in mediating these communications and regulating the reprogramming of TME, which affects the sensitivity of immunotherapy. Therefore, it is imperative to investigate the role of exosomes in TME reprogramming and the impact of exosomes on immunotherapy. Here, we review the communication role of exosomes in regulating TME remodeling and the efficacy of immunotherapy, as well as summarize the underlying mechanisms. Furthermore, we also introduce the potential application of the artificially modified exosomes as the delivery systems of antitumor drugs. Further efforts in this field will provide new insights on the roles of exosomes in intercellular communications of TME and cancer progression, thus helping us to uncover effective strategies for cancer treatment.

Prostate fibroblasts and prostate cancer associated fibroblasts exhibit different metabolic, matrix degradation and PD-L1 expression responses to hypoxia

Fibroblasts are versatile cells that play a major role in wound healing by synthesizing and remodeling the extracellular matrix (ECM). In cancers, fibroblasts play an expanded role in tumor progression and dissemination, immunosuppression, and metabolic support of cancer cells. In prostate cancer (PCa), fibroblasts have been shown to induce growth and increase metastatic potential. To further understand differences in the functions of human PCa associated fibroblasts (PCAFs) compared to normal prostate fibroblasts (PFs), we investigated the metabolic profile and ECM degradation characteristics of PFs and PCAFs using a magnetic resonance imaging and spectroscopy compatible intact cell perfusion assay. To further understand how PFs and PCAFs respond to hypoxic tumor microenvironments that are often observed in PCa, we characterized the effects of hypoxia on PF and PCAF metabolism, invasion and PD-L1 expression. We found that under normoxia, PCAFs displayed decreased ECM degradation compared to PFs. Under hypoxia, ECM degradation by PFs increased, whereas PCAFs exhibited decreased ECM degradation. Under both normoxia and hypoxia, PCAFs and PFs showed significantly different metabolic profiles. PD-L1 expression was intrinsically higher in PCAFs compared to PFs. Under hypoxia, PD-L1 expression increased in PCAFs but not in PFs. Our data suggest that PCAFs may not directly induce ECM degradation to assist in tumor dissemination, but may instead create an immune suppressive tumor microenvironment that further increases under hypoxic conditions. Our data identify the intrinsic metabolic, ECM degradation and PD-L1 expression differences between PCAFs and PFs under normoxia and hypoxia that may provide novel targets in PCa treatment.

Metabolic engineering for optimized CAR-T cell therapy

The broad effectiveness of T cell-based therapy for treating solid tumour cancers remains limited. This is partly due to the growing appreciation that immune cells must inhabit and traverse a metabolically demanding tumour environment. Accordingly, recent efforts have centred on using genome-editing technologies to augment T cell-mediated cytotoxicity by manipulating specific metabolic genes. However, solid tumours exhibit numerous characteristics restricting immune cell-mediated cytotoxicity, implying a need for metabolic engineering at the pathway level rather than single gene targets. This emerging concept has yet to be put into clinical practice as many questions concerning the complex interplay between metabolic networks and T cell function remain unsolved. This Perspective will highlight key foundational studies that examine the relevant metabolic pathways required for effective T cell cytotoxicity and persistence in the human tumour microenvironment, feasible strategies for metabolic engineering to increase the efficiency of chimeric antigen receptor T cell-based approaches, and the challenges lying ahead for clinical implementation.

Intercellular crosstalk between cancer cells and cancer-associated fibroblasts via exosomes in gastrointestinal tumors

Gastrointestinal (GI) tumors are a significant global health threat, with high rates of morbidity and mortality. Exosomes contain various biologically active molecules like nucleic acids, proteins, and lipids and can serve as messengers for intercellular communication. They play critical roles in the exchange of information between tumor cells and the tumor microenvironment (TME). The TME consists of mesenchymal cells and components of the extracellular matrix (ECM), with fibroblasts being the most abundant cell type in the tumor mesenchyme. Cancer-associated fibroblasts (CAFs) are derived from normal fibroblasts and mesenchymal stem cells that are activated in the TME. CAFs can secrete exosomes to modulate cell proliferation, invasion, migration, drug resistance, and other biological processes in tumors. Additionally, tumor cells can manipulate the function and behavior of fibroblasts through direct cell-cell interactions. This review provides a summary of the intercellular crosstalk between GI tumor cells and CAFs through exosomes, along with potential underlying mechanisms.

Exosomes define a local and systemic communication network in healthy pancreas and pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC), a lethal disease, requires a grasp of its biology for effective therapies. Exosomes, implicated in cancer, are poorly understood in living systems. Here we use the genetically engineered mouse model (ExoBow) to map the spatiotemporal distribution of exosomes from healthy and PDAC pancreas in vivo to determine their biological significance. We show that, within the PDAC microenvironment, cancer cells establish preferential communication routes through exosomes with cancer associated fibroblasts and endothelial cells. The latter being a conserved event in the healthy pancreas. Inhibiting exosomes secretion in both scenarios enhances angiogenesis, underscoring their contribution to vascularization and to cancer. Inter-organ communication is significantly increased in PDAC with specific organs as most frequent targets of exosomes communication occurring in health with the thymus, bone-marrow, brain, and intestines, and in PDAC with the kidneys, lungs and thymus. In sum, we find that exosomes mediate an organized intra- and inter- pancreas communication network with modulatory effects in vivo.