Expression of hypoxia-inducible factor 1α, glucose transporter 1, and hexokinase 2 in primary central nervous system lymphoma and the correlation with the biological behaviors

The regulatory roles and clinical significance of glycolysis in tumor

Metabolic reprogramming has been demonstrated to have a significant impact on the biological behaviors of tumor cells, among which glycolysis is an important form. Recent research has revealed that the heightened glycolysis levels, the abnormal expression of glycolytic enzymes, and the accumulation of glycolytic products could regulate the growth, proliferation, invasion, and metastasis of tumor cells and provide a favorable microenvironment for tumor development and progression. Based on the distinctive glycolytic characteristics of tumor cells, novel imaging tests have been developed to evaluate tumor proliferation and metastasis. In addition, glycolytic enzymes have been found to serve as promising biomarkers in tumor, which could provide assistance in the early diagnosis and prognostic assessment of tumor patients. Numerous glycolytic enzymes have been identified as potential therapeutic targets for tumor treatment, and various small molecule inhibitors targeting glycolytic enzymes have been developed to inhibit tumor development and some of them are already applied in the clinic. In this review, we systematically summarized recent advances of the regulatory roles of glycolysis in tumor progression and highlighted the potential clinical significance of glycolytic enzymes and products as novel biomarkers and therapeutic targets in tumor 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.

ROS signaling in innate immunity via oxidative protein modifications

The innate immune response represents the first-line of defense against invading pathogens. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been implicated in various aspects of innate immune function, which involves respiratory bursts and inflammasome activation. These reactive species widely distributed within the cellular environment are short-lived intermediates that play a vital role in cellular signaling and proliferation and are likely to depend on their subcellular site of formation. NADPH oxidase complex of phagocytes is known to generate superoxide anion radical (O2 •-) that functions as a precursor for antimicrobial hydrogen peroxide (H2O2) production, and H2O2 is utilized by myeloperoxidase (MPO) to generate hypochlorous acid (HOCl) that mediates pathogen killing. H2O2 modulates the expression of redox-responsive transcriptional factors, namely NF-kB, NRF2, and HIF-1, thereby mediating redox-based epigenetic modification. Survival and function of immune cells are under redox control and depend on intracellular and extracellular levels of ROS/RNS. The current review focuses on redox factors involved in the activation of immune response and the role of ROS in oxidative modification of proteins in macrophage polarization and neutrophil function.

Fibroblast Activation Protein and Glycolysis in Lymphoma Diagnosis: Comparison of 68Ga-FAPI PET/CT and 18F-FDG PET/CT

Our objective was to compare the diagnostic performance of 68Ga-labeled fibroblast activation protein (FAP) inhibitor (FAPI) and 18F-labeled FDG PET/CT in diagnosing lymphomas and to characterize the influence of FAP and glycolytic markers on tracer uptake by involved lesions. Methods: Participants with different lymphoma subtypes who were prospectively recruited from May 2020 to December 2021 underwent 68Ga-FAPI and 18F-FDG PET/CT. Immunohistochemistry was performed to evaluate FAP, hexokinase 2, and glucose transporter 1 (GLUT1) expression, and the paired-samples t test and Wilcoxon signed-rank test were used to compare parameters. The correlation between the immunochemistry results and tracer uptake was determined by the Spearman rank correlation coefficient. Results: In total, 186 participants (median age, 52 y [interquartile range, 41-64 y]; 95 women) were included. Dual-tracer imaging produced 3 types of imaging profiles. 18F-FDG PET possessed a higher staging accuracy (98.4%) than 68Ga-FAPI PET (86.0%). In 5,980 lymphoma lesions, 18F-FDG PET/CT detected more nodal (4,624 vs. 2,196) and extranodal (1,304 vs. 845) lesions than 68Ga-FAPI PET/CT. Additionally, 52 68Ga-FAPI-positive/18F-FDG-negative lesions and 2,939 68Ga-FAPI-negative/18F-FDG-positive lesions were observed. In many lymphoma subtypes, semiquantitative evaluation revealed no significant differences in SUVmax or target-to-liver ratios between 68Ga-FAPI and 18F-FDG PET/CT (P > 0.05). Interestingly, GLUT1 and hexokinase 2 were overexpressed both in lymphoma cells and in the tumor microenvironment, whereas FAP was expressed only in stromal cells. FAP and GLUT1 expression correlated positively with 68Ga-FAPI SUVmax (r = 0.622, P = 0.001) and 18F-FDG SUVmax (r = 0.835, P < 0.001), respectively. Conclusion: 68Ga-FAPI PET/CT was inferior to 18F-FDG PET/CT in diagnosing lymphomas with low FAP expression. However, the former may supplement the latter and help reveal the molecular profile of lymphomas.

Expression and Clinical Significance of HKII and HIF-1α in Grade Groups of Prostate Cancer

Prostate cancer (PCA) is the second leading cause of cancer-related mortality in men. The glycolytic enzymes hexokinase II (HKII) and the major regulator hypoxia-inducible factor-1α (HIF-1α) are PCA-specific biomarkers. Some studies have shown that HKII and HIF-1α are highly expressive in PCA and are associated with the growth and metastasis of treatment. Whether HKII and HIF-1α regulate the different differentiation of PCA remains largely unknown. Therefore, the study aims to explore the value of HKII and HIF-1α in different grade groups of PCA. Our data indicated that compared with normal prostate tissues, the level of mRNA and protein of HKII and HIF-1α in PCA increased significantly, besides the results showed the high expression of HKII and HIF-1α had a tendency to promote the progression and differentiation of PCA. The study also found that HKII expression was positively correlated with the expression of HIF-1α. HKII and HIF-1α were related to the degree of differentiation PCA, especially in high-grade PCA. Furthermore, the high expression of HKII was significantly associated with Gleason score and histological differentiation in clinicopathological characteristics of patients with PCA. These results were further used to confirm that the expression of HKII and HIF-1α was associated with the progression and differentiation of PCA. These experiments indicated that HKII and HIF-1α might be novel biomarkers of PCA with potential clinical application value, provide a new potential target for PCA treatment, and are expected to be used for individualized treatment in patients with PCA.

Network pharmacology combined with metabolomics to study the mechanism of Shenyan Kangfu Tablets in the treatment of diabetic nephropathy

ETHNOPHARMACOLOGICAL RELEVANCE

Shenyan Kangfu Tablets (SYKFT) is a traditional prescription evolved from Shenqi Pills. It has been included in the Synopsis of the Golden Chamber for more than 2000 years. SYKFT was listed as a national Chinese medicine protected class by the China Food and Drug Administration. Diabetic nephropathy (DN) is one of the serious microvascular diseases caused by diabetes and is also one of the important factors leading to the death of patients. The pathogenesis of DN is diverse and complex, and there is no particularly effective drug treatment. There is clinical evidence that SYKFT has a good therapeutic effect on DN with no obvious adverse effects, but the mechanism of treatment is not clear.

AIM OF THE STUDY

In this study, network pharmacology was combined with metabolomics technology to explore the mechanism of SYKFT in the treatment of DN.

MATERIALS AND METHODS

First, the research team conducted a qualitative study of the chemical components contained in SYKFT, and carried out network pharmacology to search for potential targets based on the characterized chemical components. Second, we analysed the metabolic profile of db/db mouse urine based on UHPLC-QTOF-MS technology, and biomarkers were identified by multivariate statistical analysis. Then, we performed further pathway enrichment analysis. Finally, the results of metabolomics and network pharmacology were conjointly analysed.

RESULTS

Seventy-five chemical components of SYKFT were identified. According to the TCMSP database, the corresponding targets of the qualitatively identified components were searched, and a total of 36 potentially active components and 160 targets related to DN were obtained. A total of 38 biomarkers were found in metabolomics based on UHPLC-QTOF-MS technology. Biosynthesis of unsaturated fatty acids and starch and sucrose metabolism are the most related pathways, the former of which has been rarely reported concerning DN. Finally, the results of the joint analysis show that two targets, hexokinase 2 (HK2) and maltase glucoamylase (MGAM), are the overlapping targets. It means they are not only the related targets of pathways involved in potential biomarkers in metabolomics but also the intersection targets of diseases and drugs identified by network pharmacology.

CONCLUSIONS

The study reveals that the potential mechanism of SYKFT is most related to insulin resistance (IR) in the treatment of DN. It also proves that network pharmacology combined with metabolomics to find the mechanisms by which herbs treat complex diseases is a feasible tool.

α-Lipoic Acid Maintains Brain Glucose Metabolism via BDNF/TrkB/HIF-1α Signaling Pathway in P301S Mice

The microtubule-associated protein tau is closely correlated with hypometabolism in Alzheimer’s disease (AD). α-lipoic acid (LA), which is a naturally occurring cofactor in mitochondrial, has been shown to have properties that can inhibit the tau pathology and neuronal damage in our previous research. However, if LA affects glucose metabolism when it reverses tau pathology remains unclear, especially concerning the potential mechanism. Therefore, we make a further study using the P301S mouse model (a tauopathy and AD mouse model which overexpressing fibrillary tau) to gain a clear idea of the aforementioned problems. Here, we found chronic LA administration significantly increased glucose availability by elevating glucose transporter 3 (GLUT3), GLUT4, vascular endothelial growth factor (VEGF) protein and mRNA level, and heme oxygenase-1 (HO-1) protein level in P301S mouse brains. Meanwhile, we found that LA also promoted glycolysis by directly upregulating hexokinase (HK) activity, indirectly by increasing proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and DNA repair enzymes (OGG1/2 and MTH1). Further, we found the underlying mechanism of restored glucose metabolism might involve in the activation of brain-derived neurotrophic factor (BDNF)/tyrosine Kinase receptor B (TrkB)/hypoxia-inducible factor-1α (HIF-1α) signaling pathway by LA treatment.

Expression of hypoxia-inducible factor 1α, glucose transporter 1, and hexokinase 2 in primary central nervous system lymphoma and the correlation with the biological behaviors

BACKGROUND

It has been indicated that abnormal glucose metabolism mediated by hypoxia-inducible factor 1α (HIF-1α) played an essential role in the development of solid tumor. However, there were rare studies about the role of them in primary central nervous system lymphoma (PCNSL).

OBJECTIVE

To investigate the protein levels of HIF-1α, glucose transporter 1 (GLUT1), and hexokinase 2 (HK2) in PCNSL and whether their levels are associated with prognostic factors.

METHODS

Expression of HIF-1α, GLUT1, and HK2 in 39 tumor tissues was evaluated by immunohistochemical stainning. The correlation of the expression of HIF-1α with the protein level of GLUT1 and HK2 was investigated. In addition, the association between these protein expression levels and clinical parameters and prognosis was analyzed.

RESULTS

In the tumor specimens of PCNSL, positive stainings of HIF-1α, GLUT1, and HK2 were in 23 patients (58.97%), 25 patients (64.1%), and 26 patients (66.67%), respectively, which were associated with the expression level of lactic dehydrogenase (LDH), but not with age, gender, number of lesion, ECOG score, or deep structure. The expression of HIF-1α was positively correlated with the expression of GLUT1 (p < .01, r = .749) and HK2 (p < .01, r = .787). Univariate analysis showed that upregulated GLUT1 was unfavorable predictors of progression-free survival (PFS) in PCNSL. The results of Cox proportional hazards model showed GLUT1 was significantly associated with shorter PFS (hazard ration: 5.65; 95% confidence interval: 1.23-25.84; p = .026).

CONCLUSIONS

This study indicated that there was a hypoxic microenvironment and HIF-1α was involved in the regulation of glycolysis pathway in PCNSL. GLUT1 might be a potential marker for shorter PFS in PCNSL.