Metabolic Reprogramming in Tumor Endothelial Cells

Magnetically Integrated Tumor-Vascular Interface System to Mimic Pro-angiogenic Endothelial Dysregulations for On-Chip Drug Testing

The tumor-vascular interface is a critical component of the tumor microenvironment that regulates all of the dynamic interactions between a growing tumor and the endothelial lining of the surrounding vasculature. In this paper, we report the design and development of a custom-engineered tumor-vascular interface system for investigating the early stage tumor-mediated pro-angiogenic dysfunctional behavior of the endothelium. Using representative endothelial cells and triple negative breast cancer cell lines, we established a biomimetic interface between a three-dimensional tumor tissue across a mature, functional endothelial barrier using a magnetically hybrid-integrated tumor-vascular interface system, wherein vasculature-like features containing a monolayer of endothelial cell culture on porous microfluidic channel surfaces were magnetically attached to tumor spheroids generated on a composite polymer-hydrogel microwell plate and embedded in a collagen matrix. Tumor-mediated endothelial microdynamics were characterized by their hallmark behavior such as loss of endothelial adherens junctions, increased cell density, proliferation, and changes in cell spreading and corroborated with endothelial YAP/TAZ nuclear translocation. We further confirm the feasibility of drug-mediated reversal of this pro-angiogenic endothelial organization through two different signaling mechanisms, namely, inhibition of the vascular endothelial growth factor pathway and the Notch signaling pathway, thereby demonstrating the utility of the tumor-vascular interface platform for rapid, early stage prediction of antiangiogenic drug efficacy. Overall, our work emphasizes the importance of our strategic engineering approach for identifying some unique, physiologically relevant aspects of the tumor-vascular interface, which are otherwise difficult to implement using standard in vitro approaches.

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.

Targeted anti-angiogenesis therapy for advanced osteosarcoma

To date, despite extensive research, the prognosis of advanced osteosarcoma has not improved significantly. Thus, patients experience a reduced survival rate, suggesting that a reevaluation of current treatment strategies is required. Recently, in addition to routine surgery, chemotherapy and radiotherapy, researchers have explored more effective and safer treatments, including targeted therapy, immunotherapy, anti-angiogenesis therapy, metabolic targets therapy, and nanomedicine therapy. The tumorigenesis and development of osteosarcoma is closely related to angiogenesis. Thus, anti-angiogenesis therapy is crucial to treat osteosarcoma; however, recent clinical trials found that it has insufficient efficacy. To solve this problem, the causes of treatment failure and improve treatment strategies should be investigated. This review focuses on summarizing the pathophysiological mechanisms of angiogenesis in osteosarcoma and recent advances in anti-angiogenesis treatment of osteosarcoma. We also discuss some clinical studies, with the aim of providing new ideas to improve treatment strategies for osteosarcoma and the prognosis of patients.

Survival strategies: How tumor hypoxia microenvironment orchestrates angiogenesis

During tumor development, the tumor itself must continuously generate new blood vessels to meet their growth needs while also allowing for tumor invasion and metastasis. One of the most common features of tumors is hypoxia, which drives the process of tumor angiogenesis by regulating the tumor microenvironment, thus adversely affecting the prognosis of patients. In addition, to overcome unsuitable environments for growth, such as hypoxia, nutrient deficiency, hyperacidity, and immunosuppression, the tumor microenvironment (TME) coordinates angiogenesis in several ways to restore the supply of oxygen and nutrients and to remove metabolic wastes. A growing body of research suggests that tumor angiogenesis and hypoxia interact through a complex interplay of crosstalk, which is inextricably linked to the TME. Here, we review the TME's positive contribution to angiogenesis from an angiogenesis-centric perspective while considering the objective impact of hypoxic phenotypes and the status and limitations of current angiogenic therapies.

Immunometabolism in cancer: basic mechanisms and new targeting strategy

Maturing immunometabolic research empowers immune regulation novel approaches. Progressive metabolic adaptation of tumor cells permits a thriving tumor microenvironment (TME) in which immune cells always lose the initial killing capacity, which remains an unsolved dilemma even with the development of immune checkpoint therapies. In recent years, many studies on tumor immunometabolism have been reported. The development of immunometabolism may facilitate anti-tumor immunotherapy from the recurrent crosstalk between metabolism and immunity. Here, we discuss clinical studies of the core signaling pathways of immunometabolism and their inhibitors or agonists, as well as the specific functions of these pathways in regulating immunity and metabolism, and discuss some of the identified immunometabolic checkpoints. Understanding the comprehensive advances in immunometabolism helps to revise the status quo of cancer treatment. An overview of the new landscape of immunometabolism. The PI3K pathway promotes anabolism and inhibits catabolism. The LKB1 pathway inhibits anabolism and promotes catabolism. Overactivation of PI3K/AKT/mTOR pathway and IDO, IL4I1, ACAT, Sirt2, and MTHFD2 promote immunosuppression of TME formation, as evidenced by increased Treg and decreased T-cell proliferation. The LKBI-AMPK pathway promotes the differentiation of naive T cells to effector T cells and memory T cells and promotes anti-tumor immunity in DCs.

A bibliometric analysis of the research landscape on vascular normalization in cancer

Tumor vascular normalization profoundly affects the advancement of cancer therapy. Currently, with the rapid increase in research on tumor vascular normalization, few analytical and descriptive studies have investigated the trends in its development, key research power, present research hotspots, and future outlooks. In this study, articles and reviews published between January 1, 2003, and October 29, 2022 were retrieved from Web of Science database. Subsequently, published research trends, countries/regions, institutions, authors, journals, references, and keywords were analyzed based on traditional bibliometric laws (such as Price's exponential growth, Bradford's, Lotka's, and Zipf's). Our results showed that the last two decades have seen an increase in tumor vascular normalization research. USA emerged as the preeminent contributor to the field, boasting the highest H-index and accruing the greatest quantity of publications and citations. Among institutions, Massachusetts General Hospital and Harvard University made significant contributions, and Professor RK Jain was identified as a key leader in this field. Out of 583 academic journals, Cancer Research and Clinical Cancer Research published the most articles on vascular normalization. The research focal points in the field primarily include immunotherapy, tumor microenvironments, nanomedicine, and emerging frontier themes such as metabolism and mechanomedicine. Concurrently, the challenges of vascular normalization in cancer are discussed as well. In conclusion, the study presented a thorough analysis of the literature covering the past 20 years on vascular normalization in cancer, highlighting leading countries, institutions, authors, journals, and the emerging research focal points in this field. Future studies will advance the ongoing efforts in the field of tumor vascular normalization, aiming to enhance our ability to effectively manage and treat cancer.

Aberrant tumor vasculature. Facts and pitfalls

Endothelial cells form a single cell layer lining the inner walls of blood vessels and play critical roles in organ homeostasis and disease progression. Specifically, tumor endothelial cells are heterogenous, and highly permeable, because of specific interactions with the tumor tissue environment and through soluble factors and cell-cell interactions. This review article aims to analyze different aspects of endothelial cell heterogeneity in tumor vasculature, with particular emphasis on vascular normalization, vascular permeability, metabolism, endothelial-to-mesenchymal transition, resistance to therapy, and the interplay between endothelial cells and the immune system.

Sensitive simultaneous measurements of oxygenation and extracellular pH by EPR using a stable monophosphonated trityl radical and lithium phthalocyanine

The monitoring of acidosis and hypoxia is crucial because both factors promote cancer progression and impact the efficacy of anti-cancer treatments. A phosphonated tetrathiatriarylmethyl (pTAM) has been previously described to monitor both parameters simultaneously, but the sensitivity to tackle subtle changes in oxygenation was limited. Here, we describe an innovative approach combining the pTAM radical and lithium phthalocyanine (LiPc) crystals to provide sensitive simultaneous measurements of extracellular pH (pHe) and pO2. Both parameters can be measured simultaneously as both EPR spectra do not overlap, with a gain in sensitivity to pO2 variations by a factor of 10. This procedure was applied to characterize the impact of carbogen breathing in a breast cancer 4T1 model as a proof-of-concept. No significant change in pHe and pO2 was observed using pTAM alone, while LiPc detected a significant increase in tumor oxygenation. Interestingly, we observed that pTAM systematically overestimated the pO2 compared to LiPc. In addition, we analyzed the impact of an inhibitor (UK-5099) of the mitochondrial pyruvate carrier (MPC) on the tumor microenvironment. In vitro, the exposure of 4T1 cells to UK-5099 for 24 h induced a decrease in pHe and oxygen consumption rate (OCR). In vivo, a significant decrease in tumor pHe was observed in UK-5099-treated mice, while there was no change for mice treated with the vehicle. Despite the change observed in OCR, no significant change in tumor oxygenation was observed after the UK-5099 treatment. This approach is promising for assessing in vivo the effect of treatments targeting tumor metabolism.

Steady Laminar Flow Decreases Endothelial Glycolytic Flux While Enhancing Proteoglycan Synthesis and Antioxidant Pathways

Endothelial cells in steady laminar flow assume a healthy, quiescent phenotype, while endothelial cells in oscillating disturbed flow become dysfunctional. Since endothelial dysfunction leads to atherosclerosis and cardiovascular disease, it is important to understand the mechanisms by which endothelial cells change their function in varied flow environments. Endothelial metabolism has recently been proven a powerful tool to regulate vascular function. Endothelial cells generate most of their energy from glycolysis, and steady laminar flow may reduce endothelial glycolytic flux. We hypothesized that steady laminar but not oscillating disturbed flow would reduce glycolytic flux and alter glycolytic side branch pathways. In this study, we exposed human umbilical vein endothelial cells to static culture, steady laminar flow (20 dynes/cm2 shear stress), or oscillating disturbed flow (4 ± 6 dynes/cm2 shear stress) for 24 h using a cone-and-plate device. We then measured glucose and lactate uptake and secretion, respectively, and glycolytic metabolites. Finally, we explored changes in the expression and protein levels of endothelial glycolytic enzymes. Our data show that endothelial cells in steady laminar flow had decreased glucose uptake and 13C labeling of glycolytic metabolites while cells in oscillating disturbed flow did not. Steady laminar flow did not significantly change glycolytic enzyme gene or protein expression, suggesting that glycolysis may be altered through enzyme activity. Flow also modulated glycolytic side branch pathways involved in proteoglycan and glycosaminoglycan synthesis, as well as oxidative stress. These flow-induced changes in endothelial glucose metabolism may impact the atheroprone endothelial phenotype in oscillating disturbed flow.

Molecular and metabolic orchestration of the lymphatic vasculature in physiology and pathology

Lymphangiogenesis refers to the generation of new lymphatic vessels from pre-existing ones. During development and particular adult states, lymphatic endothelial cells (LEC) undergo reprogramming of their transcriptomic and signaling networks to support the high demands imposed by cell proliferation and migration. Although there has been substantial progress in identifying growth factors and signaling pathways controlling lymphangiogenesis in the last decades, insights into the role of metabolism in lymphatic cell functions are just emerging. Despite numerous similarities between the main metabolic pathways existing in LECs, blood ECs (BEC) and other cell types, accumulating evidence has revealed that LECs acquire a unique metabolic signature during lymphangiogenesis, and their metabolic engine is intertwined with molecular regulatory networks, resulting in a tightly regulated and interconnected process. Considering the implication of lymphatic dysfunction in cancer and lymphedema, alongside other pathologies, recent findings hold promising opportunities to develop novel therapeutic approaches. In this review, we provide an overview of the status of knowledge in the molecular and metabolic network regulating the lymphatic vasculature in health and disease.

Tumor endothelial cell autophagy is a key vascular-immune checkpoint in melanoma

Tumor endothelial cells (TECs) actively repress inflammatory responses and maintain an immune-excluded tumor phenotype. However, the molecular mechanisms that sustain TEC-mediated immunosuppression remain largely elusive. Here, we show that autophagy ablation in TECs boosts antitumor immunity by supporting infiltration and effector function of T-cells, thereby restricting melanoma growth. In melanoma-bearing mice, loss of TEC autophagy leads to the transcriptional expression of an immunostimulatory/inflammatory TEC phenotype driven by heightened NF-kB and STING signaling. In line, single-cell transcriptomic datasets from melanoma patients disclose an enriched InflammatoryHigh /AutophagyLow TEC phenotype in correlation with clinical responses to immunotherapy, and responders exhibit an increased presence of inflamed vessels interfacing with infiltrating CD8+ T-cells. Mechanistically, STING-dependent immunity in TECs is not critical for the immunomodulatory effects of autophagy ablation, since NF-kB-driven inflammation remains functional in STING/ATG5 double knockout TECs. Hence, our study identifies autophagy as a principal tumor vascular anti-inflammatory mechanism dampening melanoma antitumor immunity.

Elaboration and validation of a prognostic signature associated with disulfidoptosis in lung adenocarcinoma, consolidated with integration of single-cell RNA sequencing and bulk RNA sequencing techniques

Background

Lung adenocarcinoma (LUAD), the predominant subtype of non-small cell lung cancer (NSCLC), remains a pervasive global public health concern. Disulfidoptosis, a nascent form of regulated cell death (RCD), presents an emerging field of inquiry. Currently, investigations into disulfidoptosis are in their initial stages. Our undertaking sought to integrate single-cell RNA sequencing (scRNA-seq) in conjunction with traditional bulk RNA sequencing (bulk RNA-seq) methodologies, with the objective of delineating genes associated with disulfidoptosis and subsequently prognosticating the clinical outcomes of LUAD patients.

Methods

Initially, we conducted an in-depth examination of the cellular composition disparities existing between LUAD and normal samples using scRNA-seq data sourced from GSE149655. Simultaneously, we scrutinized the expression patterns of disulfidoptosis-associated gene sets across diverse cell types. Subsequently, leveraging the bulk RNA-seq data, we formulated disulfidoptosis-related prognostic risk signatures (DRPS) employing LASSO-Cox regression. This was accomplished by focusing on genes implicated in disulfidoptosis that exhibited differential expression within endothelial cells (ECs). Sequentially, the robustness and precision of the DRPS model were rigorously verified through both internal and external validation datasets. In parallel, we executed single-cell trajectory analysis to delve into the differentiation dynamics of ECs. Concluding our study, we undertook a comprehensive investigation encompassing various facets. These included comparative assessments of enrichment pathways, clinicopathological parameters, immune cell abundance, immune response-associated genes, impacts of immunotherapy, and drug predictions among distinct risk cohorts.

Results

The scrutiny of scRNA-seq data underscored discernible disparities in cellular composition between LUAD and normal samples. Furthermore, disulfidoptosis-associated genes exhibited marked discrepancies within endothelial cells (ECs). Consequently, we formulated the Disulfidoptosis-Related Prognostic Signature (DRPS) to facilitate prognostic prediction. The prognostic nomogram based on the risk score effectively demonstrated DRPS's robust capacity to prognosticate survival outcomes. This assertion was corroborated by rigorous assessments utilizing both internal and external validation sets, thus affirming the commendable predictive accuracy and enduring stability of DRPS. Functional enrichment analysis shed light on the significant correlation of DRPS with pathways intrinsic to the cell cycle. Subsequent analysis unveiled correlations between DRPS and gene mutations characteristic of LUAD, as well as indications of an immunosuppressive status. Through drug prediction, we explored potential therapeutic agents for low-risk patients. Concluding our investigation, qRT-PCR experiments confirmed the heightened expression levels of EPHX1, LDHA, SHC1, MYO6, and TLE1 in lung cancer cell lines.

Endothelial VEGFR2-PLCγ signaling regulates vascular permeability and antitumor immunity through eNOS/Src

Endothelial phospholipase Cγ (PLCγ) is essential for vascular development; however, its role in healthy, mature, or pathological vessels is unexplored. Here, we show that PLCγ was prominently expressed in vessels of several human cancer forms, notably in renal cell carcinoma (RCC). High PLCγ expression in clear cell RCC correlated with angiogenic activity and poor prognosis, while low expression correlated with immune cell activation. PLCγ was induced downstream of vascular endothelial growth factor receptor 2 (VEGFR2) phosphosite Y1173 (pY1173). Heterozygous Vegfr2Y1173F/+ mice or mice lacking endothelial PLCγ (Plcg1iECKO) exhibited a stabilized endothelial barrier and diminished vascular leakage. Barrier stabilization was accompanied by decreased expression of immunosuppressive cytokines, reduced infiltration of B cells, helper T cells and regulatory T cells, and improved response to chemo- and immunotherapy. Mechanistically, pY1173/PLCγ signaling induced Ca2+/protein kinase C-dependent activation of endothelial nitric oxide synthase (eNOS), required for tyrosine nitration and activation of Src. Src-induced phosphorylation of VE-cadherin at Y685 was accompanied by disintegration of endothelial junctions. This pY1173/PLCγ/eNOS/Src pathway was detected in both healthy and tumor vessels in Vegfr2Y1173F/+ mice, which displayed decreased activation of PLCγ and eNOS and suppressed vascular leakage. Thus, we believe that we have identified a clinically relevant endothelial PLCγ pathway downstream of VEGFR2 pY1173, which destabilizes the endothelial barrier and results in loss of antitumor immunity.

Derivatives Incorporating Acridine, Pyrrole, and Thiazolidine Rings as Promising Antitumor Agents

Derivatives combining acridine, pyrrole, and thiazolidine rings have emerged as promising candidates in the field of antitumor drug discovery. This paper aims to highlight the importance of these three structural motifs in developing potent and selective anticancer agents. The integration of these rings within a single molecule offers the potential for synergistic effects, targeting multiple pathways involved in tumor growth and progression. Spiro derivatives were efficiently synthesized in a two-step process starting from isothiocyanates and 2-cyanoacetohydrazide. The thiourea side chain in spiro derivatives was utilized as a key component for the construction of the thiazolidine-4-one ring through regioselective reactions with bifunctional reagents, namely methyl-bromoacetate, dietyl-acetylenedicarboxylate, ethyl-2-bromopropionate, and ethyl-2-bromovalerate. These reactions resulted in the formation of a single regioisomeric product for each derivative. Advanced spectroscopic techniques, including 1D and 2D NMR, FT-IR, HRMS, and single-crystal analysis, were employed to meticulously characterize the chemical structures of the synthesized derivatives. Furthermore, the influence of these derivatives on the metabolic activity of various cancer cell lines was assessed, with IC50 values determined via MTT assays. Notably, derivatives containing ester functional groups exhibited exceptional activity against all tested cancer cell lines, boasting IC50 values below 10 μM. Particularly striking were the spiro derivatives with methoxy groups at position 3 and nitro groups at position 4 of the phenyl ring. These compounds displayed remarkable selectivity and exhibited heightened activity against HCT-116 and Jurkat cell lines. Additionally, 4-oxo-1,3-thiazolidin-2-ylidene derivatives demonstrated a significant activity against MCF-7 and HCT-116 cancer cell lines.

Stromal cells in the tumor microenvironment: accomplices of tumor progression?

The tumor microenvironment (TME) is made up of cells and extracellular matrix (non-cellular component), and cellular components include cancer cells and non-malignant cells such as immune cells and stromal cells. These three types of cells establish complex signals in the body and further influence tumor genesis, development, metastasis and participate in resistance to anti-tumor therapy. It has attracted scholars to study immune cells in TME due to the significant efficacy of immune checkpoint inhibitors (ICI) and chimeric antigen receptor T (CAR-T) in solid tumors and hematologic tumors. After more than 10 years of efforts, the role of immune cells in TME and the strategy of treating tumors based on immune cells have developed rapidly. Moreover, ICI have been recommended by guidelines as first- or second-line treatment strategies in a variety of tumors. At the same time, stromal cells is another major class of cellular components in TME, which also play a very important role in tumor metabolism, growth, metastasis, immune evasion and treatment resistance. Stromal cells can be recruited from neighboring non-cancerous host stromal cells and can also be formed by transdifferentiation from stromal cells to stromal cells or from tumor cells to stromal cells. Moreover, they participate in tumor genesis, development and drug resistance by secreting various factors and exosomes, participating in tumor angiogenesis and tumor metabolism, regulating the immune response in TME and extracellular matrix. However, with the deepening understanding of stromal cells, people found that stromal cells not only have the effect of promoting tumor but also can inhibit tumor in some cases. In this review, we will introduce the origin of stromal cells in TME as well as the role and specific mechanism of stromal cells in tumorigenesis and tumor development and strategies for treatment of tumors based on stromal cells. We will focus on tumor-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), tumor-associated adipocytes (CAAs), tumor endothelial cells (TECs) and pericytes (PCs) in stromal cells.

The role of vascular endothelial cells in tumor metastasis

Vascular endothelial cells (VECs) are an integral component of the inner lining of blood vessels, and their functions are essential for the proper functioning of the vascular system. The tight junctions formed by VECs act as a significant barrier to the intravasation and extravasation of tumor cells (TCs). In addition to that, the proliferation, activation, and migration of VECs play a vital role in the growth of new blood vessels, a process known as tumor angiogenesis, which is closely related to the malignant progression of tumors. However, during tumor progression, VECs undergo endothelial-to-mesenchymal transition (EndMT), which further promotes tumor progression. Furthermore, VECs act as the first line of defense against effector immune cells and help prevent immune cells from infiltrating into tumor tissues. VECs also secrete various cytokines that can contribute to regulating the stemness of tumor stem cells. Thus, it has been increasingly recognized that dysfunction of VECs is one of the key driving forces behind tumor metastasis, and therapeutic strategies targeting VECs have the potential to be an effective means of antitumor therapy. This review aims to present a comprehensive overview of the role and mechanisms of VECs in regulating tumor progression and metastasis, providing insights into the possibilities for the development of novel antitumor therapies that target VECs.

Targeting monocarboxylate transporters (MCTs) in cancer: How close are we to the clinics?

As a result of metabolic reprogramming, cancer cells display high rates of glycolysis, causing an excess production of lactate along with an increase in extracellular acidity. Proton-linked monocarboxylate transporters (MCTs) are crucial in the maintenance of this metabolic phenotype, by mediating the proton-coupled lactate flux across cell membranes, also contributing to cancer cell pH regulation. Among the proteins codified by the SLC16 gene family, MCT1 and MCT4 isoforms are the most explored in cancers, being overexpressed in many cancer types, from solid tumours to haematological malignancies. Similarly to what occurs in particular physiological settings, MCT1 and MCT4 are able to mediate lactate shuttles among cancer cells, and also between cancer and stromal cells in the tumour microenvironment. This form of metabolic cooperation is responsible for important cancer aggressiveness features, such as cell proliferation, survival, angiogenesis, migration, invasion, metastasis, immune tolerance and therapy resistance. The growing understanding of MCT functions and regulation is offering a new path to the design of novel inhibitors that can be foreseen in clinical practices. This review provides an overview of the role of MCT isoforms in cancer and summarizes the recent advances in their pharmacological targeting, highlighting the potential of new potent and selective MCT1 and/or MCT4 inhibitors in cancer therapeutics, and anticipating its inclusion in clinical practice.

Extracellular Lactic Acidosis of the Tumor Microenvironment Drives Adipocyte-to-Myofibroblast Transition Fueling the Generation of Cancer-Associated Fibroblasts

Lactic acidosis characterizes the tumor microenvironment (TME) and is involved in the mechanisms leading to cancer progression and dissemination through the reprogramming of tumor and local host cells (e.g., endothelial cells, fibroblasts, and immune cells). Adipose tissue also represents a crucial component of the TME which is receiving increasing attention due to its pro-tumoral activity, however, to date, it is not known whether it could be affected by the acidic TME. Now, emerging evidence from chronic inflammatory and fibrotic diseases underlines that adipocytes may give rise to pathogenic myofibroblast-like cells through the adipocyte-to-myofibroblast transition (AMT). Thus, our study aimed to investigate whether extracellular acidosis could affect the AMT process, sustaining the acquisition by adipocytes of a cancer-associated fibroblast (CAF)-like phenotype with a pro-tumoral activity. To this purpose, human subcutaneous adipose-derived stem cells committed to adipocytes (acADSCs) were cultured under basal (pH 7.4) or lactic acidic (pH 6.7, 10 mM lactate) conditions, and AMT was evaluated with quantitative PCR, immunoblotting, and immunofluorescence analyses. We observed that lactic acidosis significantly impaired the expression of adipocytic markers while inducing myofibroblastic, pro-fibrotic, and pro-inflammatory phenotypes in acADSCs, which are characteristic of AMT reprogramming. Interestingly, the conditioned medium of lactic acidosis-exposed acADSC cultures was able to induce myofibroblastic activation in normal fibroblasts and sustain the proliferation, migration, invasion, and therapy resistance of breast cancer cells in vitro. This study reveals a previously unrecognized relationship between lactic acidosis and the generation of a new CAF-like cell subpopulation from adipocytic precursor cells sustaining tumor malignancy.

Orthogonal Optimization, Characterization, and In Vitro Anticancer Activity Evaluation of a Hydrogen Peroxide-Responsive and Oxygen-Reserving Nanoemulsion for Hypoxic Tumor Photodynamic Therapy

Tumor hypoxia can seriously impede the effectiveness of photodynamic therapy (PDT). To address this issue, two approaches, termed in situ oxygen generation and oxygen delivery, were developed. The in situ oxygen generation method uses catalysts such as catalase to decompose excess H₂O₂ produced by tumors. It offers specificity for tumors, but its effectiveness is limited by the low H₂O₂ concentration often present in tumors. The oxygen delivery strategy relies on the high oxygen solubility of perfluorocarbon, etc., to transport oxygen. It is effective, but lacks tumor specificity. In an effort to integrate the merits of the two approaches, we designed a multifunctional nanoemulsion system named CCIPN and prepared it using a sonication-phase inversion composition-sonication method with orthogonal optimization. CCIPN included catalase, the methyl ester of 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO-Me), photosensitizer IR780, and perfluoropolyether. Perfluoropolyether may reserve the oxygen generated by catalase within the same nanoformulation for PDT. CCIPN contained spherical droplets below 100 nm and showed reasonable cytocompatibility. It presented a stronger ability to generate cytotoxic reactive oxygen species and consequently destroy tumor cells upon light irradiation, in comparison with its counterpart without catalase or perfluoropolyether. This study contributes to the design and preparation of oxygen-supplementing PDT nanomaterials.

The Role of Reprogrammed Glucose Metabolism in Cancer

Cancer cells reprogram their metabolism to meet biosynthetic needs and to adapt to various microenvironments. Accelerated glycolysis offers proliferative benefits for malignant cells by generating glycolytic products that move into branched pathways to synthesize proteins, fatty acids, nucleotides, and lipids. Notably, reprogrammed glucose metabolism and its associated events support the hallmark features of cancer such as sustained cell proliferation, hijacked apoptosis, invasion, metastasis, and angiogenesis. Overproduced enzymes involved in the committed steps of glycolysis (hexokinase, phosphofructokinase-1, and pyruvate kinase) are promising pharmacological targets for cancer therapeutics. In this review, we summarize the role of reprogrammed glucose metabolism in cancer cells and how it can be manipulated for anti-cancer strategies.

gC1qR: A New Target for Cancer Immunotherapy

Although breakthroughs in cancer treatment have been achieved, immunotherapy yields only modest benefits in most patients. There is still a gap in clarifying the immune evasiveness and immune-resistance mechanisms. Identifying other candidate targets for cancer immunotherapy is therefore a clear unmet clinical need. The complement system, a pillar of innate immunity, has recently entered the limelight due to its immunoregulatory functions in the tumor microenvironment (TME). In particular, gC1qR, a receptor for globular heads of C1q, serves as a promising new target and has attracted more attention. gC1qR, also named P32/C1qBP/HABP1, is a multifunctional protein that is overexpressed in various cancers and holds prognostic value. It regulates the tumorigenic, progression and metastatic properties of tumor cells through several downstream signaling pathways, including the Wnt/β-catenin, PKC-NF-κB and Akt/PKB pathways. A few preclinical experiments conducted through gC1qR interventions, such as monoclonal antibody, chimeric antigen receptor T-cell (CAR-T) therapy, and tumor vaccination, have shown encouraging results in anticancer activity. The efficacy may rely on the regulatory role on the TME, induction of tumor cells apoptosis and antiangiogenic activity. Nevertheless, the current understanding of the relationship between cancer immunotherapy and gC1qR remains elusive and often contradictory, posing both opportunities and challenges for therapeutic translation in the clinic. In this review, we focus on the current understanding of gC1qR function in cancer immunology and highlight the vital roles in regulating the TME. We also examines the rationale behind targeting gC1qR and discusses the potential for translating into clinical practice.

Transient Receptor Potential (TRP) Channels in Tumor Vascularization

Tumor diseases are unfortunately quick spreading, even though numerous studies are under way to improve early diagnosis and targeted treatments that take into account both the different characteristics associated with the various tumor types and the conditions of individual patients. In recent years, studies have focused on the role of ion channels in tumor development, as these proteins are involved in several cellular processes relevant to neoplastic transformation. Among all ion channels, many studies have focused on the superfamily of Transient Receptor Potential (TRP) channels, which are non-selective cation channels mediating extracellular Ca²⁺ influx. In this review, we examined the role of different endothelial TRP channel isoforms in tumor vessel formation, a process that is essential in tumor growth and metastasis.