miR-6869-5p Inhibits Glioma Cell Proliferation and Invasion via Targeting PGK1

Transcriptional regulation and post-translational modifications in the glycolytic pathway for targeted cancer therapy

Cancer cells largely rely on aerobic glycolysis or the Warburg effect to generate essential biomolecules and energy for their rapid growth. The key modulators in glycolysis including glucose transporters and enzymes, e.g. hexokinase 2, enolase 1, pyruvate kinase M2, lactate dehydrogenase A, play indispensable roles in glucose uptake, glucose consumption, ATP generation, lactate production, etc. Transcriptional regulation and post-translational modifications (PTMs) of these critical modulators are important for signal transduction and metabolic reprogramming in the glycolytic pathway, which can provide energy advantages to cancer cell growth. In this review we recapitulate the recent advances in research on glycolytic modulators of cancer cells and analyze the strategies targeting these vital modulators including small-molecule inhibitors and microRNAs (miRNAs) for targeted cancer therapy. We focus on the regulation of the glycolytic pathway at the transcription level (e.g., hypoxia-inducible factor 1, c-MYC, p53, sine oculis homeobox homolog 1, N6-methyladenosine modification) and PTMs (including phosphorylation, methylation, acetylation, ubiquitination, etc.) of the key regulators in these processes. This review will provide a comprehensive understanding of the regulation of the key modulators in the glycolytic pathway and might shed light on the targeted cancer therapy at different molecular levels.

Circulating B Cell-Derived Small RNA Delivered by Extracellular Vesicles: A Dialogue Mechanism for Long-Range Targeted Renal Mitochondrial Injury in Obesity

The intricate processes that govern the interactions between peripatetic immune cells and distal renal injury in obesity are not fully understood. Employing transcriptomic analysis of circulating extracellular vesicles (EVs), a marked amplification of small RNA (miR-3960) is discerned within CD3-CD19+ B cells. This RNA is found to be preferentially augmented in kidney tissues, contrasting with its subdued expression in other organs. By synthesizing dual-luciferase reporter assay with co-immunoprecipitation analysis, it is pinpointed that miR-3960 specifically targets the nuclear gene TRMT5, a pivotal actor in the methylation of mitochondrial tRNA. This liaison instigates aberrations in the post-transcriptional modifications of mitochondrial tRNA, engendering deficiencies within the electron respiratory chain, primarily attributable to the diminution of the mitochondrial bioenergetic compound (NDUFA7) complex I. Such perturbations lead to a compromised mitochondrial respiratory capacity in renal tubular cells, thereby exacerbating tubular injury. In contrast, EV blockade or miR-3960 depletion markedly alleviates renal tubular injury in obesity. This investigation unveils a hitherto unexplored pathway by which obesity-induced circulating immune cells remotely manipulate mitochondrial metabolism in target organs. The strategic targeting of obese EVs or infiltrative immune cells and their specifically secreted RNAs emerges as a promising therapeutic avenue to forestall obesity-related renal afflictions.

Circ_0027446 promotes malignant development of glioblastoma by interacting with miR-346 to up-regulate PGK1

Circular RNAs (circRNAs) can play essential roles in tumor development, including glioblastoma (GBM). The current study was performed to explore the function and mechanism of circ_0027446 in GBM progression. Circ_0027446, microRNA-346 (miR-346) and Phosphoglycerate kinase 1 (PGK1) levels were detected using reverse transcription-quantitative polymerase chain reaction assay. Cell behaviors were examined using Cell Counting Kit-8 assay, colony formation assay, EdU assay, flow cytometry, and transwell assay. Glycolytic metabolism was analyzed by commercial kits. The protein level was determined via western blot. The target interaction was analyzed by dual-luciferase reporter assay. Circ_0027446 function in vivo was explored by tumor xenograft assay. Circ_0027446 expression was significantly up-regulated in GBM samples and cells. Circ_0027446 down-regulation suppressed proliferation, invasion, glycolytic metabolism and enhanced apoptosis of GBM cells. MiR-346 was a target of circ_0027446, and circ_0027446 promoted GBM progression by sponging miR-346. PGK1 acted as a target gene of miR-346, and circ_0027446 interacted with miR-346 to regulate PGK1 expression. Overexpression of miR-346 inhibited malignant behaviors of GBM cells through down-regulating PGK1. Circ_0027446 contributed to tumor growth in vivo via miR-346/PGK1 axis. The current evidences demonstrated that circ_0027446 facilitated malignant progression of GBM through binding to miR-346 to up-regulate PGK1.

Phosphoglycerate-kinase-1 Is a Potential Prognostic Biomarker in HNSCC and Correlates With Immune Cell Infiltration

BACKGROUND/AIM

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cancer worldwide, with a high recurrence rate and a low cure rate. Phosphoglycerate kinase 1 (PGK1), an essential enzyme in the aerobic glycolysis pathway, is a prognostic marker for a variety of cancers. However, it remains unclear whether a PGK1-based immune signature can be used as a prognostic biomarker in HNSCC patients.

MATERIALS AND METHODS

We explored the potential oncogenic mechanisms of PGK1 by multiple bioinformatics analyses combined with multiple databases, including the correlation between PGK1 and prognosis, and the infiltration of immune cells in HNSCC. Functional enrichment analyses were further performed to investigate the potential role of PGK1 in HNSCC.

RESULTS

The expression of PGK1 was significantly higher in HNSCC tissues compared to normal tissues. High expression of PGK1 was associated with poor prognosis in HNSCC, and multivariate cox regression analysis showed that PGK1 could be an independent prognostic factor in HNSCC. Pathway analysis revealed that PGK1 may regulate the pathogenesis of HNSCC through the immune signaling pathway. Moreover, PGK1 expression significantly correlated with the infiltration level of 16 types of immune cells.

CONCLUSION

The current study reports that PGK1 expression was increased in HNSCC and that high PGK1 expression was closely associated with poor prognosis and immune cell infiltration, which could serve as a promising independent prognostic biomarker and potential immunotherapeutic target for HNSCC.

Regulation of phosphoglycerate kinase 1 and its critical role in cancer

Cells that undergo normal differentiation mainly rely on mitochondrial oxidative phosphorylation to provide energy, but most tumour cells rely on aerobic glycolysis. This phenomenon is called the "Warburg effect". Phosphoglycerate kinase 1 (PGK1) is a key enzyme in aerobic glycolysis. PGK1 is involved in glucose metabolism as well as a variety of biological activities, including angiogenesis, EMT, mediated autophagy initiation, mitochondrial metabolism, DNA replication and repair, and other processes related to tumorigenesis and development. Recently, an increasing number of studies have proven that PGK1 plays an important role in cancer. In this manuscript, we discussed the effects of the structure, function, molecular mechanisms underlying PGK1 regulation on the initiation and progression of cancer. Additionally, PGK1 is associated with chemotherapy resistance and prognosis in tumour patients. This review presents an overview of the different roles played by PGK1 during tumorigenesis, which will help in the design of experimental studies involving PGK1 and enhance the potential for the use of PGK1 as a therapeutic target in cancer. Video Abstract.

Circular RNA circHMCU promotes breast tumorigenesis through miR-4458/PGK1 regulatory cascade

BACKGROUND

Circular RNAs (circRNAs) are abnormally expressed in breast cancer (BC). However, the biological function and mechanism of circHMCU still need to be further explored.

METHODS

The expression levels of circHMCU, miR-4458 and phosphoglycerate kinase 1 (PGK1) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. The glucose uptake, lactate production and ATP level were assayed by related commercial kits. Cell Counting Kit-8 (CCK8), 5'-ethynyl-2'-deoxyuridine (EdU) and flow cytometry assays were used to test cell proliferation and apoptosis, respectively. The migratory and invasive abilities were detected by transwell and wound-healing assays. The relationships among circHMCU, miR-4458 and PGK1 were verified by dual-luciferase reporter assay. The function of circHMCU in tumor growth was evaluated by animal studies.

RESULTS

CircHMCU was upregulated in BC tissues and cell lines, whereas miR-4458 was downregulated. For biological experiments, circHMCU knockdown inhibited cell proliferation, migration, glycolysis, while promoted cell apoptosis. CircHMCU bound miR-4458, and miR-4458 targeted PGK1. MiR-4458 inhibition reversed circHMCM knockdown-mediated effects on BC cell malignant behaviors. MiR-4458 overexpression suppressed cell glycolysis, proliferation, and metastasis and promoted apoptosis in BC cells through PGK1 upregulation. Additionally, circHMCU suppressed tumor growth in vivo.

CONCLUSION

CircHMCU acted as an oncogenic factor by regulating the miR-4458/PGK1 axis in BC.

Silencing of lncRNA CHRM3-AS2 Expression Exerts Anti-Tumour Effects Against Glioma via Targeting microRNA-370-5p/KLF4

Objectives

Long non-coding RNAs (lncRNAs) are key regulators involved in the progression of glioma, and many functional lncRNAs are yet to be identified. This study aimed to explore the function of CHRM3-AS2, a rarely reported lncRNA, in glioma, as well as the underlying mechanisms involving miR-370-5p/KLF4.

Methods

Differentially expressed RNAs (DERs) were screened from two gene expression profiles of glioblastoma (GBM). Fluorescence in situ hybridisation was performed to determine the subcellular localisation of CHRM3-AS2. Cell viability, colony formation, apoptosis, migration, and invasion were evaluated using cell counting kit-8, colony counts, flow cytometry, wound healing, and Transwell assays, respectively. mRNA and protein expression of specific genes were measured using quantitative real-time polymerase chain reaction and western blotting, respectively. Dual luciferase reporter gene, RNA immunoprecipitation, and RNA pull-down assays were performed to identify the target relationships. A mouse xenograft model was established for in vivo validation.

Results

CHRM3-AS2 was screened as a prognosis-associated DER in GBM. CHRM3-AS2 expression was up-regulated in glioma cells, and CHRM3-AS2 was localised in the cytoplasm. Silencing of CHRM3-AS2 expression inhibited cell viability, colony formation, migration, and invasion and promoted apoptosis of U251 and SHG-44 cells. In addition, CHRM3-AS2 targeted miR-370-5p/KLF4 in glioma cells. The anti-tumour effect of CHRM3-AS2 silencing was weakened by miR-370-5p silencing or KLF4 overexpression. In vivo, silencing of CHRM3-AS2 expression inhibited tumour growth and Ki67 expression in mice. Overexpression of KLF4 also weakened the anti-tumour effect of CHRM3-AS2 silencing in mice.

Conclusions

Silencing of CHRM3-AS2 expression inhibited the malignant progression of glioma by regulating miR-370-5p/KLF4 expression.

The Value of miR-296 and miR-517c in Evaluating the Prognosis of Patients with Glioma after Radiotherapy and Chemotherapy

Objective

To explore the value of miR-296 and miR-517c in evaluating the prognosis of patients with glioma after radiotherapy and chemotherapy.

Methods

732 patients with glioma were selected from January 2012 to January 2018. According to the effect of postoperative chemotherapy, the patients were divided into two groups: the effective group and the ineffective group. The serum miR-296, miR-517c, and clinicopathological parameters of the two groups before chemotherapy were compared. The factors affecting the sensitivity of radiotherapy and chemotherapy and the predictive efficacy of miR-296 and miR-517c on the prognosis of patients were analyzed.

Results

The expression level of miR-296 in glioma tissue was significantly correlated with tumor pathological grade and depth of invasion (P < 0.05), and the expression level of miR-296 in glioma tissue was significantly correlated with tumor pathological grade (P < 0.05). Logistic regression analysis showed that tumor size, WHO grade, and serum miR-296 and miR-517c levels were all factors affecting chemosensitivity (P < 0.05). The sensitivity, specificity, accuracy, and AUC of serum miR-296 prediction were 76.95%, 89.64%, 85.35%, and 0.891, respectively. The sensitivity, specificity, accuracy, and AUC of serum miR-517c prediction were 72.81%, 86.50%, 82.19%, and 0.739, respectively.

Conclusion

miR-296 and miR-517c are closely related to the chemosensitivity and prognosis of glioma patients. High levels of miR-296 and miR-517c can enhance chemosensitivity and serve as reliable indexes to predict the prognosis of patients with glioma.

miR-6869-5p Transported by Plasma Extracellular Vesicles Mediates Renal Tubule Injury and Renin-Angiotensin System Activation in Obesity

Obesity increases the risk of other diseases, including kidney disease. Local renal tubular renin-angiotensin system (RAS) activation may play a role in obesity-associated kidney disease. Extracellular vehicles (EVs) transmit necessary information in obesity and cause remote organ damage, but the mechanism is unclear. The aim of the study was to investigate whether the plasma EVs cargo miR-6869-5p causes RAS activation and renal tubular damage. We isolated plasma EVs from obese and lean subjects and analyzed differentially-expressed miRNAs using RNA-seq. Then, EVs were co-cultured with human proximal renal tubular epithelial cells (PTECs) in vitro. Immunohistochemical pathology was used to assess the degree of RAS activation and tubule injury in vivo. The tubule damage-associated protein and RAS activation components were detected by Western blot. Obesity led to renal tubule injury and RAS activation in humans and mice. Obese-EVs induce RAS activation and renal tubular injury in PTECs. Importantly, miR-6869-5p-treated PTECs caused RAS activation and renal tubular injury, similar to Obese-EVs. Inhibiting miR-6869-5p decreased RAS activation and renal tubular damage. Our findings indicate that plasma Obese-EVs induce renal tubule injury and RAS activation via miR-6869-5p transport. Thus, miR-6869-5p in plasma Obese-EVs could be a therapeutic target for local RAS activation in obesity-associated kidney disease.

MicroRNA-16-1-3p Represses Breast Tumor Growth and Metastasis by Inhibiting PGK1-Mediated Warburg Effect

The Warburg effect (aerobic glycolysis) is a hallmark of cancer and is becoming a promising target for diagnosis and therapy. Phosphoglycerate kinase 1 (PGK1) is the first adenosine triphosphate (ATP)-generating glycolytic enzyme in the aerobic glycolysis pathway and plays an important role in cancer development and progression. However, how microRNAs (miRNAs) regulate PGK1-mediated aerobic glycolysis remains unknown. Here, we show that miR-16-1-3p inhibits PGK1 expression by directly targeting its 3′-untranslated region. Through inhibition of PGK1, miR-16-1-3p suppressed aerobic glycolysis by decreasing glucose uptake, lactate and ATP production, and extracellular acidification rate, and increasing oxygen consumption rate in breast cancer cells. Aerobic glycolysis regulated by the miR-16-1-3p/PGK1 axis is critical for modulating breast cancer cell proliferation, migration, invasion and metastasis in vitro and in vivo. In breast cancer patients, miR-16-1-3p expression is negatively correlated with PGK1 expression and breast cancer lung metastasis. Our findings provide clues regarding the role of miR-16-1-3p as a tumor suppressor in breast cancer through PGK1 suppression. Targeting PGK1 through miR-16-1-3p could be a promising strategy for breast cancer therapy.