Lactic acid in tumor invasion

Research progress on the regulatory role of lactate and lactylation in tumor microenvironment

The tumor microenvironment (TME) arises from the dynamic interactions between tumor cells and the surrounding medium, including a variety of cell types and extracellular components, which have an important impact on the genesis and development of tumors. A key player in TME is lactate, a metabolic byproduct of glycolysis, which serves as a significant energy source. Lactate has direct implications on the survival and differentiation of immune cells, the metabolic reprogramming and progression of tumor cells. Moreover, lactylation, a unique post-translational modification, exerts a regulatory effect on TME by affecting gene transcription via adding lactate groups to both histone and non-histone proteins. This review systematically and comprehensively synthesizes emerging evidence on how the lactate-lactylation axis drives immune evasion, therapy resistance, and TME remodeling, highlighting the therapeutic targets related to lactate and lactylation that dismantle this metabolic-epigenetic crosstalk.

Multifaceted roles of lactate dehydrogenase in liver cancer (Review)

Hepatocellular carcinoma (HCC) has high morbidity and mortality rates, and metabolic reprogramming of HCC cells supports the proliferation and development of tumor cells. Lactate dehydrogenase (LDH), a key metabolic enzyme, can maintain the rapid proliferative demand of tumor cells by promoting glycolysis and lactate production in HCC cells. In addition, LDH regulates redox homeostasis and influences lipid synthesis and signaling pathways, further promoting tumor invasion and metastasis. In the tumor microenvironment, LDH affects the function of immune cells and stromal cells by regulating the lactate concentration in and promoting the immune escape and angiogenesis of tumor cells. Since elevated levels of LDH are closely associated with tumor load, invasiveness and poor prognosis, LDH also has promising applications in the early diagnosis, treatment and prognostic assessment of HCC. The present study reviewed the roles of LDH in the occurrence, development, diagnosis, prognosis and treatment of HCC and explored its value as an important biomarker and potential therapeutic target, with the aim of providing a comprehensive reference for HCC‑related research and clinical practice.

Stibene glucoside prevents PM2.5 caused pulmonary fibrosis by Pseudo hypoxia, autophagy and NF-κB signal pathways

Although the association between PM2.5 exposure and pulmonary fibrosis is well-documented, the underlying molecular mechanisms remain poorly understood, and effective preventive strategies against PM2.5-induced pulmonary toxicity are yet to be established‌. This study investigated the role of reactive oxygen species (ROS)-mediated pseudo-hypoxia signaling and NF-κB pathway activation in PM2.5-triggered epithelial-mesenchymal transition (EMT) and fibrosis, alongside the therapeutic potential of the antioxidant compound stilbene glucoside (TSG). ‌In vivo‌, C57BL/6 mice exposed to PM2.5 for two months developed pulmonary fibrosis, with transcriptomic analysis revealing significant alterations in pathways associated with carbohydrate metabolism, cancer signaling, and immune-related diseases‌. Concurrently, upregulated expression of EMT markers (fibronectin, vimentin), glycolysis-related genes (PKM, LDHA), and inflammatory cytokines (TGF-beta) was observed in lung tissues‌. ‌In vitro‌, PM2.5 induced EMT in BEAS-2B cells via ROS-driven mitochondrial membrane potential collapse, mitophagy, HIF-1α activation, and NF-κB-mediated inflammation, which collectively promoted a metabolic shift toward glycolysis‌. Notably, TSG treatment attenuated PM2.5-induced pulmonary fibrosis by suppressing ROS accumulation, pseudo-hypoxia signaling, and NF-κB pathway activation. These effects correlated with restored mitochondrial function and normalized glucose metabolism in cellular models‌. ‌We come to the conclusion that PM2.5 exacerbates pulmonary fibrosis through ROS/HIF-1α and NF-κB axis-driven EMT and metabolic reprogramming. TSG, as a multifunctional antioxidant, represents a promising prophylactic agent against PM2.5-associated pulmonary damage‌.

Lactic acid metabolism: gynecological cancer's Achilles' heel

Lactic acid is significantly expressed in many cancers, including gynecological cancer, and has become a key regulator of the proliferation, development, metastasis and invasion of these cancers. In clinical and experimental studies, the level of lactic acid in gynecological cancer is closely related to metastasis and invasion, tumor recurrence and poor prognosis. Lactic acid can regulate the internal metabolic pathway of gynecological cancer cells and drive the autonomous role of non-cancer cells in gynecological cancer. In addition to being used as a source of energy metabolism by gynecological cancer cells, lactic acid can also be transported from cancer cells to neighboring cancer cells, stroma and vascular endothelial cells (ECs) to further guide metabolic reprogramming. Lactic acid is also involved in promoting inflammation and angiogenesis in gynecologic tumors. Therefore, we reviewed the mechanisms and recent advances in the production and transport of lactic acid in gynecological cancer. These advances and evidence suggest that targeted lactic acid metabolism is a promising cancer treatment.

Lactate-triggered histone lactylation contributes to podocyte epithelial-mesenchymal transition in diabetic nephropathy in mice

Diabetic nephropathy (DN) closely relates to morphological and functional changes of podocytes, and anaerobic glycolysis represents the predominant energy source of podocytes. However, it is unknown whether lactate accumulation in chronic high glucose causes epithelial-mesenchymal transition (EMT) of podocytes through lactate-derived histone lysine lactylation (HKla). Lactate levels increased in high glucose-stimulated mouse podocyte cell line MPC and blood and the kidney of diabetic mice. High glucose or exogenous lactate decreased nephrin levels while increased collagen IV and HKla levels in MPC, but co-treatment with oxamate or dichloroacetate reduced lactate levels and alleviated the decreases in nephrin and zonula occludens- 1 levels and the increases in collagen IV and α-smooth muscle actin as well as HKla levels in high glucose-cultured MPC. However, co-treatment with rotenone diversely affected these indices. Eleven intersection genes were screened in lactate raising and lowering interventions in podocytes using RNA sequencing and four genes were validated by qPCR. Furthermore, lactate-lowering treatments attenuated renal functions, EMT, and histone lactylation in the kidney of diabetic mice. Additionally, the increased lactate might result from the upregulated monocarboxylate transporter 2 in the mitochondria and the decreased pyruvate dehydrogenase activity. Together, we reveal the role of histone lactylation in driving the EMT phenotype of podocytes in chronic high glucose state, subsequently promoting the pathological process of DN. Our study provides a reference for the study of the relationship between lactate-induced histone lactylation modification and diabetic complications.

The characteristics and functional significance of disulfidptosis-related genes in head and neck squamous cell carcinoma

Disulfidptosis is a newfound programmed cell death (PCD) mode characterized by disulfide stress. Nevertheless, the characteristics and functional significance of disulfidptosis-related genes in head and neck squamous cell carcinoma (HNSCC) are still largely unknown. In this study, several computer-aided bioinformatic analyses were performed. The Nonnegative Matrix Factorization (NMF) method classified The Cancer Genome Atlas (TCGA) patients into two clusters according to the expression of disulfidptosis-related genes. The relative compositions of cells in the tumor microenvironment (TME), mutant landscape, lasso regression analysis, and predicted clinical outcome were performed by analyzing bulk RNA-sequencing data. Besides, single-cell sequencing data (scRNA) was analyzed by Seurat, CopyKAT, and monocle2 to reveal the expression characteristics of disulfidptosis-related genes. Moreover, the spatial distribution characteristics of each cell subgroup in the section and the functional significance of cancer-associated fibroblasts (CAFs) were elucidated by STUtility, SpaCET, and SPATA2. Here, two clusters with different expression characteristics of disulfidptosis-related genes were identified. Cluster 1 (C1) patients had a worse prognosis and a higher proportion of stromal cells but lower effector T cell infiltration than cluster 2 (C2). A novel prognostic model was established and verified in our patient cohort. Additionally, diploid and inflammatory CAFs (iCAFs) showed higher disulfidptosis-related gene expression levels. Furthermore, the CCNC and CHMP1B expressions significantly changed following CAFs differentiation. Disulfidptosis-related genes exhibited extensive and differential spatial expression on tissue sections. Collectively, our study may contribute to revealing the function of disulfidptosis, and improve the expansion of knowledge of crosstalk between cancer cells and CAFs.

SULT2B1: a novel therapeutic target in colorectal cancer via modulation of AKT/PKM2-mediated glycolysis and proliferation

BACKGROUND

Sulfotransferase family 2B member 1 (SULT2B1) is involved in regulating cell proliferation, migration and metabolism. However, there is still dispute regarding whether SULT2B1 acts as an oncogene or a suppressor, and the intrinsic mechanisms in modulating tumor progression need to be further elucidated.

METHODS

This work aims to reveal the relationship among SULT2B1, AKT, PKM2 signaling and glycolytic pathways, and provided a theoretical basis for SULT2B1 as a potential therapeutic target for CRC.Bioinformatics methods, immunohistochemistry (IHC) and immunoblotting assays were performed to analyze the correlation between SULT2B1 and colorectal cancer (CRC). The effect of SULT2B1 on cell proliferation and migration were investigated by several phenotypic experiments in vitro and animal studies. The SULT2B1 interacting proteins were determined by immunofluorescence, immunoprecipitation and GST-pull down assays. Immunoblotting and mCherry-GFP-LC3 assays were performed to analysis autophagy. Chromatin immunoprecipitation (CHIP) assay was utilized to detect the effect of SULT2B1 in regulating transcription. Small molecule agonist/antagonist was used to modify protein activity and therefore analyze the mutual relationships.

RESULTS

SULT2B1 is a predictive biomarker that is abnormally overexpressed in CRC tissues. Overexpression of SULT2B1 promoted cell proliferation and migration, while its knockout suppressed these processes. Furthermore, SULT2B1 could directly interact with the oncogene AKT and thereby enhance the activity of AKT-mTORC1 signaling. Furthermore, PKM2 was found to bind with SULT2B1, and regulated by SULT2B1 at both transcription and degradation levels. Moreover, blocking glycolysis attenuated the promoting effect of OE-SULT2B1.

CONCLUSION

SULT2B1 acts as an oncogene in CRC via modulating the AKT/PKM2 axis, therefore making it a promising diagnostic and therapeutic target for CRC.

Coating Dormant Collagenase-Producing Bacteria with Metal-Anesthetic Networks for Precision Tumor Therapy

Tumor malignancy highly depends on the stiffness of tumor matrix, which mainly consists of collagen. Despite the destruction of tumor matrix is conducive to tumor therapy, it causes the risk of tumor metastasis. Here, metal-anesthetic network-coated dormant collagenase-producing Clostridium is constructed to simultaneously destruct tumor matrix and inhibit tumor metastasis. By metal-phenolic complexation and π-π stacking interactions, a Fe3+-propofol network is formed on bacterial surface. Coated dormant Clostridium can selectively germinate and rapidly proliferate in tumor sites due to the ability of carried Fe3+ ions to promote bacterial multiplication. Intratumoral colonization of Clostridium produces sufficient collagenases to degrade tumor collagen mesh and the loaded propofol restrains tumor metastasis by inhibiting tumor cell migration and invasion. Meanwhile, the delivered Fe3+ ions are reduced to the Fe2+ form by intracellular glutathione, thereby inducing potent Fenton reaction to trigger lipid peroxidation and ultimate ferroptosis of tumor cells. In addition to a satisfactory safety, a single intratumoral injection of coated dormant Clostridium not only effectively retards the growth of established large primary tumors, but also significantly suppresses distal lung metastasis in two different orthotopic tumor models. This work proposes a strategy to develop advanced therapeutics for malignant tumor treatment and metastasis prevention.

Shenqifuzheng injection inhibits lactic acid-induced cisplatin resistance in NSCLC by affecting FBXO22/p53 axis through FOXO3

BACKGROUND

Non-small cell lung cancer (NSCLC) accounts for 80% of lung cancers. Cisplatin (DDP)-based combination chemotherapy is the main treatment of NSCLC. Due to resistance to DDP, 5-year overall survival rate of NSCLC patients is very low. Shenqifuzheng injection (SQFZ) is essential for lung cancer progression. However, whether SQFZ plays a role in DDP resistance in NSCLC and its molecular mechanism remains unclear.

METHODS

Levels of FOXO3, FBXO22 and p53 in NSCLC tissues and cells were assessed by RT-qPCR and Western blot. Cell proliferation and apoptosis were analyzed utilizing CCK-8, Colony formation and Flow cytometry assays. Lactate (LA) levels were tested via ELISA. ChIP and Dual luciferase reporter assays validated regulatory relationship between FOXO3 and FBXO22. Immunoprecipitation assay evaluated p53 ubiquitination levels. The subcutaneous tumor model of nude mice was constructed. TUNEL staining detected apoptosis in tissues, and IHC assessed expression of Ki67, FOXO3, FBXO22 and p53.

RESULTS

FOXO3 was decreased, whereas LA and FBXO22 were increased in NSCLC patients. LA led to a higher DDP resistance in A549/DDP cells, while SQFZ reversed this effect by upregulating FOXO3. Furthermore, FBXO22 was a downstream effecter of FOXO3 and FBXO22 affected p53 ubiquitination to reverse the inhibitory effect of SQFZ. We next found SQFZ inhibited LA-induced DDP resistance in NSCLC via FOXO3/FBXO22/p53 axis. Finally, SQFZ regulated LA-mediated DDP resistance in NSCLC nude mice.

CONCLUSION

SQFZ influences LA-induced DDP resistance in NSCLC via FOXO3/FBXO22/p53 pathway, providing a promising agent for NSCLC treatment.

TGF-β2 enhances glycolysis in chondrocytes via TβRI/p-Smad3 signaling pathway

Chondrocytes rely heavily on glycolysis to maintain the metabolic homeostasis and cartilage matrix turnover. Glycolysis in chondrocytes is remodeled by diverse biochemical and biomechanical factors due to the sporty joint microenvironment. Transforming growth factor-β2 (TGF-β2), one of the most abundant TGF-β superfamily members in chondrocytes, has increasingly attracted attention in cartilage physiology and pathology. Although previous studies have emphasized the importance of TGF-β superfamily members on cell metabolism, whether and how TGF-β2 modulates glycolysis in chondrocytes remains elusive. In the current study, we investigated the effects of TGF-β2 on glycolysis in chondrocytes and explored the underlying biomechanisms. The results showed that TGF-β2 could enhance glycolysis in chondrocytes by increasing glucose consumption, up-regulating liver-type ATP-dependent 6-phosphofructokinase (Pfkl) expression, and boosting lactate production. The TGF-β2 signal entered chondrocytes via TGF-β receptor type I (TβRI), and activated p-Smad3 signaling to regulate the glycolytic pathway. Subsequent experiments employing specific inhibitors of TβRI and p-Smad3 further substantiated the role of TGF-β2 in enhancement of glycolysis via TβRI/p-Smad3 axis in chondrocytes. The results provide new understanding of the metabolic homeostasis in chondrocytes induced by TGF-β superfamily and might shed light on the prevention and treatment of related osteoarticular diseases.

Factors Determining Epithelial-Mesenchymal Transition in Cancer Progression

Epithelial-mesenchymal transition (EMT) is a process in which an epithelial cell undergoes multiple modifications, acquiring both morphological and functional characteristics of a mesenchymal cell. This dynamic process is initiated by various inducing signals that activate numerous signaling pathways, leading to the stimulation of transcription factors. EMT plays a significant role in cancer progression, such as metastasis and tumor heterogeneity, as well as in drug resistance. In this article, we studied molecular mechanisms, epigenetic regulation, and cellular plasticity of EMT, as well as microenvironmental factors influencing this process. We included both in vivo and in vitro models in EMT investigation and clinical implications of EMT, such as the use of EMT in curing oncological patients and targeting its use in therapies. Additionally, this review concludes with future directions and challenges in the wide field of EMT.

Cuproptosis-related gene DLAT is a biomarker of the prognosis and immune microenvironment of gastric cancer and affects the invasion and migration of cells

OBJECTIVE

Cuproptosis is a novel cell death dependent on mitochondrial respiration and regulated by copper. This study aimed to investigate the cuproptosis-related gene DLAT potential value in gastric cancer (GC).

METHODS

Bioinformatics was used to analyze DLAT expression. DLAT expression in GC cell lines was detected using qRT-PCR. Cell proliferation ability was assessed using CCK8 and cell cycle assay. Cell migration and invasion were assessed using wound healing and transwell assay. A prognostic assessment was performed through survival and Cox regression analysis. DLAT protein expression was analyzed through HPA immunohistochemistry. Biological functions and processes were analyzed through GO and KEGG enrichment analysis and PPI. Correlation with immune cell infiltration and immune checkpoint genes was analyzed for DLAT.

RESULTS

DLAT expression was upregulated in GC tissues and cells and correlated with shorter survival for patients. Age, gender, histological typing, lymph node metastasis, and distant metastasis were identified as independent prognostic factors affecting OS in GC. DLAT protein was upregulated in GC. The biological functions and pathways enriched in DLAT were mainly linked to mitochondrial respiration and the TCA cycle. The expression of DLAT was found to be positively correlated with the infiltration of Th and Th2 immune cells and only positively correlated with the expression of the BTN2A1 immune checkpoint gene.

CONCLUSION

DLAT has the potential to serve as a prognostic assessment factor in GC. The expression of DLAT was correlated with immune infiltration and tumor immune escape, providing a new target for immunotherapy of GC.

Mito-Specific Nutri-Hijacker Synergizing Mitochondrial Metabolism and Glycolysis Intervention for Enhanced Antitumor Bioenergetic Therapy

Metabolic rewiring, a dynamic metabolic phenotype switch, confers that tumors exist and proliferate after fitness (or preadaptation) in harsh environmental conditions. Glycolysis deprivation was considered to be a tumor's metabolic Achilles heel. However, metabolic configuration can flexibly retune the mitochondrial metabolic ability when glycolysis is scared, potentially resulting in more aggressive clones. To address the challenge of mitochondrial reprogramming, an antiglycolytic nanoparticle (GRPP NP) containing a novel mitochondrial-targeted reactive oxygen species (ROS) generator (diIR780) was prepared to hijack glucose and regulate mitochondria, thus completely eliminating tumorigenic energy sources. In this process, GRPP NPs@diIR780 can catalyze endogenous glucose, leading to significantly suppressed glycolysis. Moreover, diIR780 can be released and selectively accumulated around mitochondria to generate toxic ROS. These combined effects, in turn, can hamper mitochondrial metabolism pathways, which are crucial for driving tumor progression. This synchronous intervention strategy enables utter devastation of metabolic rewiring, providing a promising regiment to eradicate tumor lesions without recurrence.

Functionalized liposomes: an enticing nanocarrier for management of glioma

Glioma is one of the most severe central nervous systems (CNS)-specific tumors, with rapidly growing malignant glial cells accounting for roughly half of all brain tumors and having a poor survival rate ranging from 12 to 15 months. Despite being the most often used technique for glioma therapy, conventional chemotherapy suffers from low permeability of the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) to anticancer drugs. When it comes to nanocarriers, liposomes are thought of as one of the most promising nanocarrier systems for glioma treatment. However, owing to BBB tight junctions, non-targeted liposomes, which passively accumulate in most cancer cells primarily via the increased permeability and retention effect (EPR), would not be suitable for glioma treatment. The surface modification of liposomes with various active targeting ligands has shown encouraging outcomes in the recent times by allowing various chemotherapy drugs to pass across the BBB and BBTB and enter glioma cells. This review article introduces by briefly outlining the landscape of glioma, its classification, and some of the pathogenic causes. Further, it discusses major barriers for delivering drugs to glioma such as the BBB, BBTB, and tumor microenvironment. It further discusses modified liposomes such as long-acting circulating liposomes, actively targeted liposomes, stimuli responsive liposomes. Finally, it highlighted the limitations of liposomes in the treatment of glioma and the various actively targeted liposomes undergoing clinical trials for the treatment of glioma.

Fusobacterium periodonticum BCT protein targeting glucose metabolism to promote the epithelial-mesenchymal transition of esophageal cancer cells by lactic acid

BACKGROUND

The cancer microbiota was considered the main risk factor for cancer progression. We had proved that Fusobacterium periodonticum (F.p) was higher abundance in Esophageal cancer(EC)tissues. Bioinformation analysis found that BCT was a key virulence protein of F.p. However, little is known about the role and mechanism of BCT in EC. This study aimed to recognize the key virulence protein of F.p and explore the mechanism of BCT in promoting EC.

METHODS

We constructed a eukaryotic expression vector and purified the recombinant protein BCT. CCK8 used to analyzed the activity of EC after treated by different concentration of BCT. UPLC-MS/MS and ELISA used to detect the metabonomics and metabolites. The ability of migration and invasion was completed by transwell assay. RT-QPCR, WB used to analyze the expression of relevant genes.

RESULTS

Our data showed that BCT was higher expression in EC tumor tissues (p < 0.05) and BCT in 20 µg/mL promoted the survival, invasion and migration of EC cells (EC109) (p < 0.05). Meanwhile, UPLC-MS/MS results suggested that BCT resulted in an augmentation of hypotaurine metabolism, arachidonic acid metabolism, glycolysis/gluconeogenesis, tryptophan metabolism, citrate cycle activity in EC109. The metabolic changes resulted in decreasing in glucose and pyruvate levels but increase in lactate dehydrogenase (LDH) activity and lactic acid (LA) as well as the expression of glucose transporter 1, Hexokinase 2, LDH which regulated the glycolysis were all changed (p < 0.05). The BCT treatment upregulated the expression of TLR4, Akt, HIF-1α (p < 0.05) which regulated the production of LA. Furthermore, LA stimulation promoted the expression of GPR81, Wnt, and β-catenin (p < 0.05), thereby inducing EMT and metastasis in EC109 cells.

CONCLUSION

Altogether, these findings identified that impact of BCT in regulation of glycolysis in EC109 and its involves the TLR4/Akt/HIF-1α pathway. Meanwhile, glycolysis increasing the release of LA and promote the EMT of EC109 by GPR81/Wnt/β-catenin signaling pathway. In summary, our findings underscore the potential of targeting BCT as an innovative strategy to mitigate the development of EC.

SLC2A3 promotes tumor progression through lactic acid-promoted TGF-β signaling pathway in oral squamous cell carcinoma

BACKGROUNDS

Oral squamous cell carcinoma is a malignant tumor of the head and neck, and its molecular mechanism remains to be explored.

METHODS

By analyzing the OSCC data from the TCGA database, we found that SLC2A3 is highly expressed in OSCC patients. The expression level of SLC2A3 was verified by RT-PCR and western blotting in OSCC cell lines. The function of SLC2A3 in OSCC cell lines and Lactic acid in SLC2A3-knockdown OSCC cells were detected by colony formation, CCK8, transwell, and wound healing assays. The effect of SLC2A3 on tumor growth and metastasis was tested in vivo. GSEA and Western blot were used to analyze and validate tumor phenotypes and signaling pathway molecules.

RESULTS

We analyzed OSCC datasets in the TCGA database and found that SLC2A3 had abnormally high expression and was associated with poor prognosis. We also found that oral squamous cell carcinoma cells had increased proliferation, migration, invasion, EMT phenotype, and glycolysis due to SLC2A3 overexpression. Conversely, SLC2A3 knockdown had the opposite effect. Our in vivo experiments confirmed that SLC2A3 overexpression promoted tumor growth and metastasis while knockdown inhibited it. We also observed that high SLC2A3 expression led to EMT and the activation of the TGF-β signaling pathway, while knockdown inhibited it. Interestingly, exogenous lactic acid restored the EMT, proliferation, migration, and invasion abilities of oral cancer cells inhibited by knocking down SLC2A3.

CONCLUSIONS

Our study reveals that SLC2A3 expression was up-regulated in OSCC. SLC2A3 activates the TGF-β signaling pathway through lactic acid generated from glycolysis, thus regulating the biological behavior of OSCC.

The cell stress and immunity cycle in cancer: Toward next generation of cancer immunotherapy

The cellular stress and immunity cycle is a cornerstone of organismal homeostasis. Stress activates intracellular and intercellular communications within a tissue or organ to initiate adaptive responses aiming to resolve the origin of this stress. If such local measures are unable to ameliorate this stress, then intercellular communications expand toward immune activation with the aim of recruiting immune cells to effectively resolve the situation while executing tissue repair to ameliorate any damage and facilitate homeostasis. This cellular stress-immunity cycle is severely dysregulated in diseased contexts like cancer. On one hand, cancer cells dysregulate the normal cellular stress responses to reorient them toward upholding growth at all costs, even at the expense of organismal integrity and homeostasis. On the other hand, the tumors severely dysregulate or inhibit various components of organismal immunity, for example, by facilitating immunosuppressive tumor landscape, lowering antigenicity, and increasing T-cell dysfunction. In this review we aim to comprehensively discuss the basis behind tumoral dysregulation of cellular stress-immunity cycle. We also offer insights into current understanding of the regulators and deregulators of this cycle and how they can be targeted for conceptualizing successful cancer immunotherapy regimen.

Effect of different hypoxic and hypobaric interventions on blood gas and erythrocyte-related indicators in rats

OBJECTIVES

To explore the effects of hypoxic and hypobaric conditions on blood gas and erythrocyte-related indicators in rats.

METHODS

SD male rats were exposed to low-pressure hypoxic conditions simulating an altitude of 6500 m in a small or a large experimental cabin. Abdominal aortic blood samples were collected and blood gas indicators, red blood cells (RBCs) count, and hemoglobin (Hb) content were measured. The effects of exposure to different hypoxia times, different hypoxia modes, normal oxygen recovery after hypoxia, and re-hypoxia after hypoxia preconditioning on blood gas indicators, RBCs count and Hb content were investigated.

RESULTS

The effect of blood gas indicators was correlated with the length of exposure time of hypoxia and the reoxygenation after leaving the cabin. Hypoxia caused acid-base imbalance and its severity was associated with the duration of hypoxia; hypoxia also led to an increase in RBCs count and Hb content, and the increase was also related to the time exposed to hypoxia. The effects of reoxygenation on acid-base imbalance in rats caged in a small animal cabin were more severe that those in a large experimental cabin. Acetazolamide alleviated the effects of reoxygenation after leaving the cabin. Different hypoxia modes and administration of acetazolamide had little effect on RBCs count and Hb content. Normal oxygen recovery can alleviate the reoxygenation and acid-base imbalance of hypoxic rats after leaving the cabin and improve the increase in red blood cell and hemoglobin content caused by hypoxia. The improvement of hypoxia preconditioning on post hypoxia reoxygenation is not significant, but it can alleviate the acid-base imbalance caused by hypoxia in rats and to some extent improve the increase in red blood cell and hemoglobin content caused by hypoxia.

CONCLUSIONS

Due to excessive ventilation and elevated RBCs count and Hb content after hypoxia reoxygenation, oxygen partial pressure and other oxygenation indicators in hypoxic rats are prone to become abnormal, while blood gas acid-base balance indicators are relatively stable, which are more suitable for evaluating the degree of hypoxia injury and related pharmacological effects in rats.

Targeting the hedgehog pathway in MET mutation cancers and its effects on cells associated with cancer development

The mutation of MET plays a crucial role in the initiation of cancer, while the Hedgehog (Hh) pathway also plays a significant role in cell differentiation and the maintenance of tumor stem cells. Conventional chemotherapy drugs are primarily designed to target the majority of cell populations within tumors rather than tumor stem cells. Consequently, after a brief period of remission, tumors often relapse. Moreover, the exclusive targeting of tumor stemness cell disregards the potential for other tumor cells to regain stemness and acquire drug resistance. As a result, current drugs that solely target the HGF/c-MET axis and the Hh pathway demonstrate only moderate efficacy in specific types of cancer. Mounting evidence indicates that these two pathways not only play important roles in cancer but also exert significant influence on the development of resistance to single-target therapies through the secretion of their own ligands. In this comprehensive review, we analyze and compare the potential impact of the Hh pathway on the tumor microenvironment (TME) in HGF/c-MET-driven tumor models, as well as the interplay between different cell types. Additionally, we further substantiate the potential and necessity of dual-pathway combination therapy as a critical target in MET addicted cancer treatment. Video Abstract.

Histone lactylation regulates cancer progression by reshaping the tumor microenvironment

As a major product of glycolysis and a vital signaling molecule, many studies have reported the key role of lactate in tumor progression and cell fate determination. Lactylation is a newly discovered post-translational modification induced by lactate. On the one hand, lactylation introduced a new era of lactate metabolism in the tumor microenvironment (TME), and on the other hand, it provided a key breakthrough point for elucidation of the interaction between tumor metabolic reprogramming and epigenetic modification. Studies have shown that the lactylation of tumor cells, tumor stem cells and tumor-infiltrating immune cells in TME can participate in the development of cancer through downstream transcriptional regulation, and is a potential and promising tumor treatment target. This review summarized the discovery and effects of lactylation, as well as recent research on histone lactylation regulating cancer progression through reshaping TME. We also focused on new strategies to enhance anti-tumor effects via targeting lactylation. Finally, we discussed the limitations of existing studies and proposed new perspectives for future research in order to further explore lactylation targets. It may provide a new way and direction to improve tumor prognosis.

The potential role of reprogrammed glucose metabolism: an emerging actionable codependent target in thyroid cancer

Although the incidence of thyroid cancer is increasing year by year, most patients, especially those with differentiated thyroid cancer, can usually be cured with surgery, radioactive iodine, and thyroid-stimulating hormone suppression. However, treatment options for patients with poorly differentiated thyroid cancers or radioiodine-refractory thyroid cancer have historically been limited. Altered energy metabolism is one of the hallmarks of cancer and a well-documented feature in thyroid cancer. In a hypoxic environment with extreme nutrient deficiencies resulting from uncontrolled growth, thyroid cancer cells utilize "metabolic reprogramming" to satisfy their energy demand and support malignant behaviors such as metastasis. This review summarizes past and recent advances in our understanding of the reprogramming of glucose metabolism in thyroid cancer cells, which we expect will yield new therapeutic approaches for patients with special pathological types of thyroid cancer by targeting reprogrammed glucose metabolism.

Glycolysis-cholesterol metabolic axis in immuno-oncology microenvironment: emerging role in immune cells and immunosuppressive signaling

Cell proliferation and function require nutrients, energy, and biosynthesis activity to duplicate repertoires for each daughter. It is therefore not surprising that tumor microenvironment (TME) metabolic reprogramming primarily orchestrates the interaction between tumor and immune cells. Tumor metabolic reprogramming affords bioenergetic, signaling intermediates, and biosynthesis requirements for both malignant and immune cells. Different immune cell subsets are recruited into the TME, and these manifestations have distinct effects on tumor progression and therapeutic outcomes, especially the mutual contribution of glycolysis and cholesterol metabolism. In particularly, glycolysis-cholesterol metabolic axis interconnection plays a critical role in the TME modulation, and their changes in tumor metabolism appear to be a double-edged sword in regulating various immune cell responses and immunotherapy efficacy. Hence, we discussed the signature manifestation of the glycolysis-cholesterol metabolic axis and its pivotal role in tumor immune regulation. We also highlight how hypothetical combinations of immunotherapy and glycolysis/cholesterol-related metabolic interventions unleash the potential of anti-tumor immunotherapies, as well as developing more effective personalized treatment strategies.

Ultrahigh-performance liquid chromatography-high-resolution mass spectrometry-based plasma metabolomics study of thymoma and thymic hyperplasia

RATIONALE

Thymoma is a rare malignant tumor but it is the most common primary tumor of the anterior mediastinum. The current imaging methods for thymoma screening suffer from false positive rate problems, and thymoma pathogenesis remains elusive. Study of thymoma metabolic characteristics could provide clues for improving the diagnosis and understanding the pathogenesis of thymoma.

METHODS

Metabolic profiling of plasma from thymoma and thymic hyperplasia patients was performed using ultrahigh-performance liquid chromatography combined with high-resolution mass spectrometry in both positive and negative ionization modes. After pre- and post-processing, the dataset was divided into three age groups and statistical analysis was performed to select differential metabolites of thymoma. For feature identification, experimental tandem mass spectra were matched to those of databases and available chemical standards, and also manually annotated with plausible chemical structures to ensure high identification confidence.

RESULTS

A total of 47 differential metabolites were identified in thymoma. Significantly higher levels of histidine, sphinganine 1-phosphate, lactic acid dimer, phenylacetylglutamine, LPC (18:3) and LPC (16:1), and significantly lower levels of phenylalanine, indole-3-propionic acid (IPA), hippuric acid and mesobilirubinogen were associated with thymoma. Tryptophan level in thymoma-associated myasthenia gravis (TAMG) was significantly lower than that of the MG(-) group. IPA and hippuric acid abundances exhibited increasing trends from indolent to aggressive thymoma.

CONCLUSIONS

Our study revealed aberrant aromatic amino acid metabolism and fatty acid oxidation might be associated with thymoma. The identified unique metabolic characteristics of thymoma may provide valuable information for study of the molecular mechanism of thymoma pathogenesis, and improvement of diagnosis and discovery of new therapeutic strategies for thymoma.

Novel Gene Signatures Promote Epithelial-Mesenchymal Transition (EMT) in Glucose Deprivation-Based Microenvironment to Predict Recurrence-Free Survival in Hepatocellular Carcinoma

Background

Current research studies have suggested that glucose deprivation (GD)-based tumor microenvironment (TME) can promote epithelial-mesenchymal transition (EMT) of tumor cells, leading to tumor invasion and metastasis. However, no one has yet studied detailedly the synthetic studies that include GD features in TME with EMT status. In our research, we comprehensively developed and validated a robust signature regarding GD and EMT status to provide prognostic value for patients with liver cancer.

Methods

GD and EMT status were estimated with transcriptomic profiles based on WGCNA and t-SNE algorithms. Two cohorts of training (TCGA_LIHC) and validation (GSE76427) datasets were analyzed with the Cox regression and logistic regression analyses. We identified a 2-mRNA signature to establish a GD-EMT-based gene risk model for the prediction of HCC relapse.

Results

Patients with significant GD-EMT status were divided into two subgroups: GD^low/EMT^low and GD^high/EMT^high, with the latter having significantly worse recurrence-free survival (P < 0.01). We employed the least absolute shrinkage and selection operator (LASSO) technique as a method for HNF4A and SLC2A4 filtering and constructing a risk score for risk stratification. In the multivariate analysis, this risk score predicted recurrence-free survival (RFS) in both the discovery and validation cohorts and remained valid in patients stratified by TNM stage and age at diagnosis. The nomogram that combines risk score and TNM stage as well as age produces improved performance and net benefits in the analysis of calibration and decision curves in training and validation groups.

Conclusions

The GD-EMT-based signature predictive model may provide a prognosis classifier for HCC patients with a high risk of postoperative recurrence to decrease the relapse rate.

Lactate: a pearl dropped in the ocean-an overlooked signal molecule in physiology and pathology

Lactate, once recognized as a wasty product from anaerobic glycolysis, is proved to be a pivotal signal molecule. Lactate accumulation occurs in diverse physiological and pathological settings due to the imbalance between lactate production and clearance. Under the condition with drastic changes in local microenvironment, such as tumorigenesis, inflammation, and microbial infection, the glycolysis turns to be active in surrounding cells leading to increased lactate release. Meanwhile, lactate can be utilized by these cells as an energy substrate and acts as a signal molecule to regulate cell functions through receptor-dependent or independent pathways. In this review, we tended to tease out the contribution of lactate in tumor progression and immunomodulation. And we also discussed the accessory role of lactate, beyond as the energy source only, in the growth of invading pathogens.

A Model of Basement Membrane-Associated Gene Signature Predicts Liver Hepatocellular Carcinoma Response to Immune Checkpoint Inhibitors

Liver hepatocellular carcinoma (LIHC) is a highly lethal malignant tumor originating from the digestive system, which is a serious threat to human health. In recent years, immunotherapy has shown significant therapeutic effects in the treatment of LIHC, but only for a minority of patients. The basement membrane (BM) plays an important role in the occurrence and development of tumors, including LIHC. Therefore, this study is aimed at establishing a risk score model based on basement membrane-related genes (BMRGs) to predict patient prognosis and response to immunotherapy. First, we defined three patterns of BMRG modification (C1, C2, and C3) by consensus clustering of BMRG sets and LIHC transcriptome data obtained from public databases. Survival analysis showed that patients in the C2 group had a better prognosis, and Gene Set Variation Analysis (GSVA) revealed that the statistically significant pathways were mainly enriched in the C2 group. Moreover, we performed Weighted Correlation Network Analysis (WGCNA) on the above three subgroups and obtained 179 intersecting genes. We further applied function enrichment analyses, and the results demonstrated that they were mainly enriched in metabolism-related pathways. Furthermore, we conducted the LASSO regression analysis and obtained 4 BMRGs (MPV17, GNB1, DHX34, and MAFG) that were significantly related to the prognosis of LIHC patients. We further constructed a prognostic risk score model based on the above genes, which was verified to have good predictive performance for LIHC prognosis. In addition, we analyzed the correlation between the risk score and the tumor immune microenvironment (TIM), and the results showed that the high-risk scoring group tended to be in an immunosuppressed status. Finally, we investigated the relationship between the risk score and LIHC immune function. The results demonstrated that the risk score was closely related to the expression levels of multiple immune checkpoints. Patients in the low-risk group had significantly higher IPS scores, and patients in the high-risk group had lower immune escape and TIDE score. In conclusion, we established a novel risk model based on BMRGs, which may serve as a biomarker for prognosis and immunotherapy in LIHC.

Acidic and hypoxic tumor microenvironment regulation by CaO2-loaded polydopamine nanoparticles

Hypoxia and high accumulation of lactic acid in the tumor microenvironment provide fertile soil for tumor development, maintenance and metastasis. Herein, we developed a calcium peroxide (CaO₂)-loaded nanostructure that can play a role of "one stone kill two birds", i.e., acidic and hypoxic tumor microenvironment can be simultaneously regulated by CaO₂ loaded nanostructure. Specifically, CaO₂-loaded mesoporous polydopamine nanoparticles modified with sodium hyaluronate (denoted as CaO₂@mPDA-SH) can gradually accumulate in a tumor site. CaO₂ exposed in acidic microenvironment can succeed in consuming the lactic acid with oxygen generation simultaneously, which could remodel the acid and hypoxia tumor microenvironment. More importantly, the relief of hypoxia could further reduce lactate production from the source by down-regulating the hypoxia inducible factor-1α (HIF-1α), which further down-regulated the glycolysis associated enzymes including glycolysis-related glucose transporter 1 (GLUT1) and lactate dehydrogenase A (LDHA). As a result, CaO₂@mPDA-SH alone without the employment of other therapeutics can dually regulate the tumor hypoxia and lactic acid metabolism, which efficiently represses tumor progression in promoting immune activation, antitumor metastasis, and anti-angiogenesis.

Cell-Matrix Interactions in Renal Fibrosis

Renal fibrosis is a hallmark of end-stage chronic kidney disease. It is characterized by increased accumulation of extracellular matrix (ECM), which disrupts cellular organization and function within the kidney. Here, we review the bi-directional interactions between cells and the ECM that drive renal fibrosis. We will discuss the cells involved in renal fibrosis, changes that occur in the ECM, the interactions between renal cells and the surrounding fibrotic microenvironment, and signal transduction pathways that are misregulated as fibrosis proceeds. Understanding the underlying mechanisms of cell-ECM crosstalk will identify novel targets to better identify and treat renal fibrosis and associated renal disease.

Glioma diagnosis and therapy: Current challenges and nanomaterial-based solutions

Glioma is often referred to as one of the most dreadful central nervous system (CNS)-specific tumors with rapidly-proliferating cancerous glial cells, accounting for nearly half of the brain tumors at an annual incidence rate of 30-80 per a million population. Although glioma treatment remains a significant challenge for researchers and clinicians, the rapid development of nanomedicine provides tremendous opportunities for long-term glioma therapy. However, several obstacles impede the development of novel therapeutics, such as the very tight blood-brain barrier (BBB), undesirable hypoxia, and complex tumor microenvironment (TME). Several efforts have been dedicated to exploring various nanoformulations for improving BBB permeation and precise tumor ablation to address these challenges. Initially, this article briefly introduces glioma classification and various pathogenic factors. Further, currently available therapeutic approaches are illustrated in detail, including traditional chemotherapy, radiotherapy, and surgical practices. Then, different innovative treatment strategies, such as tumor-treating fields, gene therapy, immunotherapy, and phototherapy, are emphasized. In conclusion, we summarize the article with interesting perspectives, providing suggestions for future glioma diagnosis and therapy improvement.

Lactate metabolism in human health and disease

The current understanding of lactate extends from its origins as a byproduct of glycolysis to its role in tumor metabolism, as identified by studies on the Warburg effect. The lactate shuttle hypothesis suggests that lactate plays an important role as a bridging signaling molecule that coordinates signaling among different cells, organs and tissues. Lactylation is a posttranslational modification initially reported by Professor Yingming Zhao’s research group in 2019. Subsequent studies confirmed that lactylation is a vital component of lactate function and is involved in tumor proliferation, neural excitation, inflammation and other biological processes. An indispensable substance for various physiological cellular functions, lactate plays a regulatory role in different aspects of energy metabolism and signal transduction. Therefore, a comprehensive review and summary of lactate is presented to clarify the role of lactate in disease and to provide a reference and direction for future research. This review offers a systematic overview of lactate homeostasis and its roles in physiological and pathological processes, as well as a comprehensive overview of the effects of lactylation in various diseases, particularly inflammation and cancer.

Poly(methacrylate citric acid) as a Dual Functional Carrier for Tumor Therapy

Owing to its pH-sensitive property and chelating Cu²⁺ effect, poly(methacrylate citric acid) (PCA) can be utilized as a dual functional nanocarrier to construct a nanodelivery system. Negatively charged carboxyl groups can interact with positively charged antineoplastic drugs through electrostatic interaction to form stable drug nanoparticles (NPs). Through drug experimental screening, doxorubicin (DOX) was selected as the model drug, PCA/DOX NPs with a diameter of 84 nm were prepared, and the drug-loading content was 68.3%. PCA/DOX NPs maintained good stability and a sustained release profile. Cell experiments presented that PCA/DOX NPs could inhibit effectively the growth of 4T1 cells; the IC₅₀ value was decreased by approximately 15-fold after incubation for 72 h. The cytotoxicity toward H9C2 was decreased significantly. Moreover, based on its ability to efficiently adsorb copper ions, PCA showed good vascular growth inhibition effect in vitro. Furthermore, animal experiments showed that PCA/DOX NPs presented stronger anticancer effects than DOX; the tumor inhibition rate was increased by 1.5-fold. Myocardial toxicity experiments also confirmed that PCA reduced the cardiotoxicity of DOX. In summary, PCA/DOX NPs show good antitumor efficacy and low toxicity, and have good potential for clinical application.

Bisphenols A and S Alter the Bioenergetics and Behaviours of Normal Urothelial and Bladder Cancer Cells

Bisphenol A (BPA) and bisphenol S (BPS) are used in the production of plastics. These endocrine disruptors can be released into the environment and food, resulting in the continuous exposure of humans to bisphenols (BPs). The bladder urothelium is chronically exposed to BPA and BPS due to their presence in human urine samples. BPA and BPS exposure has been linked to cancer progression, especially for hormone-dependent cancers. However, the bladder is not recognized as a hormone-dependent tissue. Still, the presence of hormone receptors on the urothelium and their role in bladder cancer initiation and progression suggest that BPs could impact bladder cancer development. The effects of chronic exposure to BPA and BPS for 72 h on the bioenergetics (glycolysis and mitochondrial respiration), proliferation and migration of normal urothelial cells and non-invasive and invasive bladder cancer cells were evaluated. The results demonstrate that chronic exposure to BPs decreased urothelial cells' energy metabolism and properties while increasing them for bladder cancer cells. These findings suggest that exposure to BPA and BPS could promote bladder cancer development with a potential clinical impact on bladder cancer progression. Further studies using 3D models would help to understand the clinical consequences of this exposure.

Essential role of aerobic glycolysis in epithelial-to-mesenchymal transition during carcinogenesis

Epithelial-to-mesenchymal transition (EMT) confers the most lethal characteristics to cancer cells i.e., metastasis and resistance to chemo-and-radio-therapy, and therefore exhibit an appealing target in the field of oncology. Research in the past decade has demonstrated the crucial role of aerobic glycolysis in EMT, which is generally credited as the glucose metabolism for the creation of biomass such as fatty acids, amino acids, and nucleotides thereby providing building blocks for limitless proliferation. In the present review, apart from discussing EMT's evident role in the metastatic process and cancer stemness, we also talked about the vital role of glycolytic enzymes viz. GLUTs, HKs, PGI, PFK-1, aldolase, enolase, PK, LDHA, etc. in the induction of the EMT process in cancerous cells.

Progress of Nanomaterials in Photodynamic Therapy Against Tumor

Photodynamic therapy (PDT) is an advanced therapeutic strategy with light-triggered, minimally invasive, high spatiotemporal selective and low systemic toxicity properties, which has been widely used in the clinical treatment of many solid tumors in recent years. Any strategies that improve the three elements of PDT (light, oxygen, and photosensitizers) can improve the efficacy of PDT. However, traditional PDT is confronted some challenges of poor solubility of photosensitizers and tumor suppressive microenvironment. To overcome the related obstacles of PDT, various strategies have been investigated in terms of improving photosensitizers (PSs) delivery, penetration of excitation light sources, and hypoxic tumor microenvironment. In addition, compared with a single treatment mode, the synergistic treatment of multiple treatment modalities such as photothermal therapy, chemotherapy, and radiation therapy can improve the efficacy of PDT. This review summarizes recent advances in nanomaterials, including metal nanoparticles, liposomes, hydrogels and polymers, to enhance the efficiency of PDT against malignant tumor.

Bisphenol A Alters the Energy Metabolism of Stromal Cells and Could Promote Bladder Cancer Progression

Simple Summary

Our research brings new insight on the potential impact of bisphenol A on bladder cancer progression. By evaluating the effects of bisphenol A on the stromal environment of bladder cancer, we aimed to demonstrate that this endocrine disruptor could promote bladder cancer invasion through alteration of the energy metabolism of stromal cells, specifically on bladder fibroblasts and cancer-associated fibroblasts. These findings could modify the understanding of bladder cancer since bladder tissue is not recognized as a hormone-sensitive tissue. Consequently, our study suggests that endocrine disruptors, such as bisphenol A, could impact bladder cancer progression.

Abstract

Bisphenol A (BPA) is an endocrine-disrupting molecule used in plastics. Through its release in food and the environment, BPA can be found in humans and is mostly excreted in urine. The bladder is therefore continuously exposed to this compound. BPA can bind to multiple cell receptors involved in proliferation, migration and invasion pathways, and exposure to BPA is associated with cancer progression. Considering the physiological concentrations of BPA in urine, we tested the effect of nanomolar concentrations of BPA on the metabolism of bladder fibroblasts and cancer-associated fibroblasts (CAFs). Our results show that BPA led to a decreased metabolism in fibroblasts, which could alter the extracellular matrix. Furthermore, CAF induction triggered a metabolic switch, similar to the Warburg effect described in cancer cells. Additionally, we demonstrated that nanomolar concentrations of BPA could exacerbate this metabolic switch observed in CAFs via an increased glycolytic metabolism, leading to greater acidification of the extracellular environment. These findings suggest that chronic exposure to BPA could promote cancer progression through an alteration of the metabolism of stromal cells.