miR-4458 suppresses glycolysis and lactate production by directly targeting hexokinase2 in colon cancer cells

miR-373-3p promotes aerobic glycolysis in colon cancer cells by targeting MFN2

MicroRNAs (miRNAs) are implicated in the development of cancers and may serve as potential targets for therapy. However, the functions and underlying mechanisms of miRNAs in cancers are not well understood. This work aims to study the role of miR-373-3p in colon cancer cells. We find that the expression of miR-373-3p mimics promotes and the miR-373-3p inhibitor suppresses aerobic glycolysis and proliferation of colon cancer cells. Mechanistically, miR-373-3p inhibits the expression of MFN2, a gene that is known to suppress glycolysis, which leads to the activation of glycolysis and eventually the proliferation of cells. In a nude mouse tumor model, the expression of miR-373-3p in colon cancer cells promotes tumor growth by enhancing lactate formation, which is inhibited by the co-expression of MFN2 in the cells. Administration of the miR-373-3p antagomir blunts in vivo tumor growth by decreasing lactate production. In addition, in human colon cancers, the expression levels of miR-373-3p are increased, while those of MFN2 mRNA are decreased, and the increase of miR-373-3p is associated with the decrease of MFN2 mRNA. Our results reveal a previously unknown function and underlying mechanism of miR-373-3p in the regulation of glycolysis and proliferation in cancer cells and underscore the potential of targeting miR-373-3p for colon cancer treatment.

Utilizing machine learning to identify nifuroxazide as an inhibitor of ubiquitin-specific protease 21 in a drug repositioning strategy

Ubiquitin-specific protease (USP), an enzyme catalyzing protein deubiquitination, is involved in biological processes related to metabolic disorders and cancer proliferation. We focused on constructing predictive models tailored to unveil compounds boasting USP21 inhibitory attributes. Six models, Extra Trees Classifier, Random Forest Classifier, LightGBM Classifier, XGBoost Classifier, Bagging Classifier, and a convolutional neural network harnessed from empirical data were selected for the screening process. These models guided our selection of 26 compounds from the FDA-approved drug library for further evaluation. Notably, nifuroxazide emerged as the most potent inhibitor, with a half-maximal inhibitory concentration of 14.9 ± 1.63 μM. The stability of protein-ligand complexes was confirmed using molecular modeling. Furthermore, nifuroxazide treatment of HepG2 cells not only inhibited USP21 and its established substrate ACLY but also elevated p-AMPKα, a downstream functional target of USP21. Intriguingly, we unveiled the previously unknown capacity of nifuroxazide to increase the levels of miR-4458, which was identified as downregulating USP21. This discovery was substantiated by manipulating miR-4458 levels in HepG2 cells, resulting in corresponding changes in USP21 protein levels in line with its predicted interaction with ACLY. Lastly, we confirmed the in vivo efficacy of nifuroxazide in inhibiting USP21 in mice livers, observing concurrent alterations in ACLY and p-AMPKα levels. Collectively, our study establishes nifuroxazide as a promising USP21 inhibitor with potential implications for addressing metabolic disorders and cancer proliferation. This multidimensional investigation sheds light on the intricate regulatory mechanisms involving USP21 and its downstream effects, paving the way for further exploration and therapeutic development.

Current Advances on Nanomaterials Interfering with Lactate Metabolism for Tumor Therapy

Increasing numbers of studies have shown that tumor cells prefer fermentative glycolysis over oxidative phosphorylation to provide a vast amount of energy for fast proliferation even under oxygen-sufficient conditions. This metabolic alteration not only favors tumor cell progression and metastasis but also increases lactate accumulation in solid tumors. In addition to serving as a byproduct of glycolytic tumor cells, lactate also plays a central role in the construction of acidic and immunosuppressive tumor microenvironment, resulting in therapeutic tolerance. Recently, targeted drug delivery and inherent therapeutic properties of nanomaterials have attracted great attention, and research on modulating lactate metabolism based on nanomaterials to enhance antitumor therapy has exploded. In this review, the advanced tumor therapy strategies based on nanomaterials that interfere with lactate metabolism are discussed, including inhibiting lactate anabolism, promoting lactate catabolism, and disrupting the "lactate shuttle". Furthermore, recent advances in combining lactate metabolism modulation with other therapies, including chemotherapy, immunotherapy, photothermal therapy, and reactive oxygen species-related therapies, etc., which have achieved cooperatively enhanced therapeutic outcomes, are summarized. Finally, foreseeable challenges and prospective developments are also reviewed for the future development of this field.

Recent advances microRNAs and metabolic reprogramming in colorectal cancer research

Colorectal cancer (CRC) is a cancer with the highest incidence and mortality. Alteration of gene expression is the main pathophysiological mechanism of CRC, which results in disturbed signaling pathways and cellular metabolic processes. MicroRNAs are involved in almost all pathophysiological processes and are correlative with colorectal cancer metabolism, proliferation, and chemotherapy resistance. Metabolic reprogramming, an important feature of cancer, is strongly correlative with the development and prognosis of cancers, including colorectal cancer. MicroRNAs can target enzymes involved in metabolic processes, thus playing a regulatory role in tumor metabolism. The disorder of the signaling pathway is another characteristic of tumor, which induces the occurrence and proliferation of tumors, and is closely correlative with the prognosis and chemotherapy resistance of tumor patients. MicroRNAs can target the components of the signaling pathways to regulate their transduction. Understanding the function of microRNAs in the occurrence and proliferation of CRC provides novel insights into the optimal treatment strategies, prognosis, and development of diagnosis in CRC. This article reviews the relationship between CRC and microRNA expression and hopes to provide new options for the diagnosis and treatment of CRC.

Aiding Cancer's "Sweet Tooth": Role of Hexokinases in Metabolic Reprogramming

Hexokinases (HKs) convert hexose sugars to hexose-6-phosphate, thus trapping them inside cells to meet the synthetic and energetic demands. HKs participate in various standard and altered physiological processes, including cancer, primarily through the reprogramming of cellular metabolism. Four canonical HKs have been identified with different expression patterns across tissues. HKs 1-3 play a role in glucose utilization, whereas HK 4 (glucokinase, GCK) also acts as a glucose sensor. Recently, a novel fifth HK, hexokinase domain containing 1 (HKDC1), has been identified, which plays a role in whole-body glucose utilization and insulin sensitivity. Beyond the metabolic functions, HKDC1 is differentially expressed in many forms of human cancer. This review focuses on the role of HKs, particularly HKDC1, in metabolic reprogramming and cancer progression.

MiR-4458-loaded gelatin nanospheres target COL11A1 for DDR2/SRC signaling pathway inactivation to suppress the progression of estrogen receptor-positive breast cancer

RNA interference is a promising way to treat cancer and the construction of a stable drug delivery system is critically important for its application. Gelatin nanospheres (GNs) comprise a biodegradable drug vehicle with excellent biocompatibility, but there are limited studies on its delivery and role in the stabilization of miRNA and siRNA. Breast cancer is the most diagnosed type of female cancer worldwide. Abnormal miRNA expression is closely related to the occurrence and progression of estrogen receptor-positive (ER+) breast cancer. In this study, miR-4458 was upregulated in ER+ breast cancer and could inhibit MCF-7 cell viability, colony formation, migration, and invasion. Collagen type XI alpha 1 (COL11A1) was identified as a directly interacting protein of miR-4458 and an important component of the extracellular matrix. High COL11A1 expression was positively correlated with poor prognosis, lower overall survival, disease-free survival, and a late tumor-node-metastasis stage. COL11A1 knockdown could inhibit MCF-7 cell migration and invasion. GNs were used to load a miR-4458 mimic or COL11A1 siRNA (si-COL11A1) to achieve sustained and controlled release in xenograft nude mice. Their tumor volume was decreased, tumor cell apoptosis was promoted, and hepatic metastasis was significantly inhibited. Moreover, the DDR2/SRC signaling pathway was inactivated after transfection with the miR-4458 mimic and si-COL11A1. In conclusion, GNs can be potentially used to deliver siRNA or miRNA, and miR-4458 and COL11A1 can be possible targets for ER+ breast cancer treatment.

Emerging role of non-coding RNAs in glucose metabolic reprogramming and chemoresistance in colorectal cancer

Metabolic reprogramming plays a critical role in colorectal cancer (CRC). It contributes to CRC by shaping metabolic phenotypes and causing uncontrolled proliferation of CRC cells. Glucose metabolic reprogramming is common in carcinogenesis and cancer progression. Growing evidence has implicated the modifying effects of non-coding RNAs (ncRNAs) in glucose metabolic reprogramming and chemoresistance in CRC. In this review, we have summarized currently published studies investigating the role of ncRNAs in glucose metabolic alterations and chemoresistance in CRC. Elucidating the interplay between ncRNAs and glucose metabolic reprogramming provides insight into exploring novel biomarkers for the diagnosis and prognosis prediction of CRC.

MicroRNA-4458 Regulates PD-L1 Expression to Enhance Anti-tumor Immunity in NSCLC via Targeting STAT3

MicroRNA-4458 (miR-4458) has been reported to be associated with several cancers including non-small-cell lung cancer (NSCLC), while its role in tumor immunity remains unclear. The purpose of the current research was to explore the anti-tumor immunity of miR-4458 in NSCLC. The results showed that the expression level of miR-4458 decreased and STAT3 increased in NSCLC tissues and cells. For in vitro experiments, miR-4458 mimics suppressed cell proliferation and decreased the expression level of PD-L1. Moreover, STAT3 was confirmed as a target gene of miR-4458. Upregulation of STAT3 level ameliorated the inhibitive effects of miR-4458 on cells proliferation and PD-L1 expression in cells. For in vivo studies, overexpression of miR-4458 hindered tumor growth, decreased the proportion of PD-1⁺ T cells, the expression of PD-L1 and IL-10, upregulated the proportion of CD4⁺ T, CD8⁺ T cells as well as the expression of IFN-γ and IL-2, which were all reversed by overexpression of STAT3, and the effects of STAT3 were counteracted after knockdown of PD-L1. MiR-4458 overexpression enhanced anti-tumor immunity via targeting STAT3 to block the PD-L1/PD-1 pathway.

MicroRNA and cyclooxygenase-2 in breast cancer

Cancer remains a major public health problem worldwide and the latest statistics show that breast cancer (BC) is among the most frequent in women. MicroRNAs (miRNAs; miRs) and cyclooxygenase-2 (COX-2) are new diagnostic and therapeutic biomarkers for monitoring BC. COX-2 is a prominent tumor-associated inflammatory factor highly expressed in human tumor cells, including BC. Expression of COX-2 contributes to tumor growth, metastasis and recurrence. MiRs are a group of short (~22 nucleotides), noncoding regulatory RNAs that downregulate gene expression post-transcriptionally and play vital roles in regulating cancer development and progression. Interestingly, there are a group of miRNAs differentially expressed in breast tumor tissue. Understanding the pathway linking miRNAs to COX-2 can provide novel insight for suppressing COX-2 expression via gene silencing thereby leading to the development of selective miRNA inhibitors. Further research can also reveal key intermediate players and their potential as therapeutic targets. Given the association between different miRNAs and COX-2 expression in BC, this review presents a comprehensive overview of the current literature concerning how miRNAs and COX-2 signaling interact in BC progression.

The effects and mechanisms of isoliquiritigenin loaded nanoliposomes regulated AMPK/mTOR mediated glycolysis in colorectal cancer

In this study, isoliquiritigenin (ISL) incorporated nanoliposomes were prepared and their effects on colorectal cancer (CRC) cell lines were investigated. Herein, we sought to explore the anti-cancer mechanisms of ISL loaded nanoliposomes (ISL-NLs) on AMP-activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathways mediated glycolysis. Also, the key targets such as caveolin 1 (CAV1), glucose transporters and Akt/mTOR that promote glycolysis, and are activated via the induction of α-enolase (ENO1), fructose bisphosphate aldolase A (ALDOA) and monocarboxylate transporter 4 (MCT4) expressions were also investigated. It was shown that ISL-NLs significantly suppressed the proliferation and glucose uptake of CRC cell by potentially regulating the glycolysis and lactate targets as well as pathways that formed the basis of the anti-CRC effects of ISL-NLs. The mechanism underlying this effect was further validated via the regulation of some key targets such as ENO1, ALDOA, lactate dehydrogenase A (LDHA) and MCT4 in glycolysis coupled with cellular myelocytomatosis oncogene (c-myc), hypoxia-inducible factor 1-alpha (HIF-1α) in protein kinase B/mTOR (Akt/mTOR) pathways. Moreover, the AMPK proteins were identified to be up-regulated while the lactic acid production was suppressed by ISL-NLs in the CRC cells, indicating that ISL-NLs had an inhibitory effect on AMPK mediated glycolysis and lactate production. Altogether, these results have provided insights into the mechanism underlying the key role that liposomal ISL played in the multiple inhibition of AMPK and Akt/mTOR mediated glycolysis and lactate generation, which may be regulated as the alternative metabolic pathways of CRC as well as serve as adjuvant therapy for the disease.

Circ_0001667 knockdown blocks cancer progression and attenuates adriamycin resistance by depleting NCOA3 via releasing miR-4458 in breast cancer

Accumulating evidence suggests that developmental chemoresistance in cancers is closely associated with the dysregulation of circular RNA transcriptions. The objective of this study is to disclose the role of circ_0001667 and provide a potential functional mechanism in breast cancer. Quantitative real-time PCR was applied for the analysis of circ_0001667, microRNA-4458 (miR-4458) and nuclear receptor coactivator 3 (NCOA3) expression. In adriamycin (ADM)-resistant cell lines, we investigated cell proliferation using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and colony formation assay. Cell migration and cell invasion were determined by transwell assay. The protein levels of multi-drug resistance-1, matrix metalloproteinases-9, cleaved-caspase3, cleaved-caspase9 and NCOA3 were detected by western blot. ADM resistance was ascertained by IC50 value using MTT assay. Cell apoptosis was checked by flow cytometry assay. The putative relationship between miR-4458 and circ_0001667 and NCOA3 was validated by pull-down assay, dual-luciferase reporter assay or RNA Immunoprecipitation assay. Circ_0001667 knockdown inhibited MCF-7/ADM and MDA-MB-231/ADM cell proliferation, migration, invasion and ADM resistance. MiR-4458 was a target of circ_0001667, and its expression was decreased in ADM-resistant tumor tissues and cells. MiR-4458 inhibition reversed the effects of circ_0001667 knockdown. In depth, NCOA3 was a target of circ_0001667, and circ_0001667 knockdown weakened NCOA3 expression by releasing miR-4458. MCF-7/ADM and MDA-MB-231/ADM cell proliferation, migration, invasion, and ADM resistance inhibited by miR-4458 restoration were recovered by NCOA3 overexpression. Circ_0001667 knockdown also repressed tumor growth and ADM resistance in vivo. Circ_0001667 knockdown blocks cancer progression and attenuates ADM resistance by depleting NCOA3 via releasing miR-4458 in breast cancer.

Circular RNA circ_0000337 contributes to osteosarcoma via the miR-4458/BACH1 pathway

BACKGROUND

As the most prevalent primary bone malignancy in children and adolescents, osteosarcoma (OS) has attracted increasing attention. The role of circRNAs in OS has been elucidated in some reports, but many circRNAs remain unexplored. Circ_0000337 has only been revealed as an oncogenic circRNA in esophageal squamous cell carcinoma. Yet whether circ_0000337 exerts any specific function in OS has not been unmasked.

METHODS

RT-qPCR was used for measurement of circ_0000337, miR-4458 and BACH1 mRNA levels. Western blot was conducted to detect BACH1 protein. CCK-8 assay, Casepase-3 activity assay and transwell assay were utilized to assess changes on cellular processes. Cytoplasmic/nuclear fractionation assay was conducted for circ_0000337 localization in OS cells. Luciferase reporter assay and RIP assay were performed to validate the interaction between miR-4458 and circ_0000337 or BACH1.

RESULTS

Circ_0000337 expression was upregulated in OS cell lines and it silence hindered OS cell proliferation and migration. MiR-4458 was downregulated in OS cells and miR-4458 upregulation suppressed OS cell growth and migration. Importantly, circ_0000337 sponged miR-4458 to elevate BACH1 expression, thus facilitating OS development.

CONCLUSIONS

This research for the first time documented that circ_0000337 promoted OS progression via sponging miR-4458 and thus elevating BACH1 expression, offering rational therapeutic target for OS.

Radix Tetrastigma Hemsleyani Flavone Inhibits the Occurrence and Development of Ovarian Cancer Cells by Regulating miRNA-4458 Expression

Ovarian cancer (OC) has been identified to have the highest mortality rate among gynecological tumors. Most patients are diagnosed at an advanced stage because of its asymptomatic nature and a lack of effective early diagnostic methods. Advanced-stage cancer cells are prone to metastasis which reduces the efficacy of standard therapies. Thus, we evaluated the effect of different concentrations of radix tetrastigma hemsleyani flavone (RTHF) on SKOV3 OC cells. Our findings indicated a significant inhibition in cell proliferation, migration, and invasion. RTHF treatment resulted in a significant increase in p21 protein expression, whereas the expression of cyclin D1, MMP-2, and MMP-9 has reportedly decreased. In addition, the expression of miRNA-4458 expression increased significantly in a dose-dependent manner. Co-transfection of miRNA-4458 mimics into SKOV3 cells revealed that overexpressed miRNA-4458 can increase SKOV3 cell proliferation and p21 protein expression. Reduced cell migration and invasion were also observed along with decreased expression of cyclin D1, MMP-2, and MMP-9. Furthermore, inhibition of miRNA-4458 expression reversed the RTHF effect on SKOV3 cell proliferation, migration, invasion, and cyclin D1, MMP-2, and MMP-9 expression. These results indicate that RTHF reduces the proliferation, migration, and invasion of OC cells, and the underlying mechanism is associated with the upregulation of miRNA-4458 expression. These findings provide a new treatment strategy for advanced OC.

Emerging roles of non-coding RNAs in the metabolic reprogramming of tumor-associated macrophages

Macrophages are the most common immune cells in the tumor microenvironment, and tumor-associated macrophages play an important role in cancer development. Metabolic reprogramming is important for the functional plasticity of macrophages. Studies investigating the relevance of non-coding RNAs (ncRNAs) in human cancer found that ncRNAs can regulate the metabolism of cancer cells and tumor-associated macrophages. NcRNAs include short ncRNAs, long ncRNAs (lncRNAs), and circular RNAs (circRNAs). The most common short ncRNAs are microRNAs, which regulate glucose, lipid, and amino acid metabolism in macrophages by acting on metabolism-related pathways and targeting metabolism-related enzymes and proteins, and are therefore involved in cancer progression. The role of lncRNAs and circRNAs in the metabolism of tumor-associated macrophages remains unclear. LncRNAs affect the glucose metabolism of macrophages, whereas their role in lipid and amino acid metabolism is not clear. CircRNAs regulate amino acid metabolism in macrophages. The roles of ncRNAs in energy metabolism and the underlying mechanisms need to be investigated further. Here, we summarize recent findings on the involvement of ncRNAs in metabolic reprogramming in tumor-associated macrophages, which affect the tumor microenvironment and play important roles in the development of cancer. Improving our understanding of the effects of ncRNAs on metabolic reprogramming of tumor-associated macrophages may facilitate the development of effective clinical therapies.

Aberrant lactate dehydrogenase A signaling contributes metabolic signatures in pancreatic cancer

Background

Pancreatic cancer (PC) has the lowest 5-year survival rate; therefore, new early screening methods and therapeutic targets are still urgently required. Emerging technologies such as metabolomic-based liquid biopsy may contribute to the field. We found aberrant lactate dehydrogenase A (LDHA) signaling to be an unfavorable biomarker for PC.

Methods

A total of 9 genes of the glycolysis pathway were detected by enrichment analysis in the PC Gene Expression Omnibus (GEO) dataset. The relationship between LDHA/pyruvate kinase (PKM)/fructose biphosphate aldolase A (ALDOA)/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and patient survival was analyzed by Kaplan-Meier plotting analysis of The Cancer Genome Atlas (TCGA). The detection of changing metabolites in the serum of PC patients was performed using a nuclear magnetic resonance (NMR) spectrometer.

Results

We found LDHA was an independent predictor of overall survival (OS) in PC patients (P<0.001). Consistent with genetic aberrance of LDHA, we identified significant alterations in patients’ glycolysis-related metabolites, including upregulation of lactic acid and downregulation of pyruvic acid. A 0.956 area under the curve (AUC) was achieved using the combinative metabolites score of lactic acid, pyruvic acid, citric acid, and glucose to distinguish PC from healthy controls.

Conclusions

Aberrant LDHA signaling is an unfavorable biomarker for PC and consequential metabolic changes constitute potential diagnostic signatures of PCs.

The pivotal role of MicroRNAs in glucose metabolism in cancer

Cancer cells are able to undergo aerobic glycolysis and metabolize glucose to lactate instead of oxidative phosphorylation, which is known as Warburg effect. Accumulating evidence has revealed that microRNAs regulate cancer cell metabolism, which manifest a higher rate of glucose metabolism. Various signaling pathways along with glycolytic enzymes are responsible for the emergence of glycolytic dependence. MicroRNAs are a class of non-coding RNAs that are not translated into proteins but regulate target gene expression or in other words function pre-translationally and post-transcriptionally. MicroRNAs have been shown to be involved in various biological processes, including glucose metabolism via targeting major transcription factors, enzymes, oncogenes or tumor suppressors alongside the oncogenic signaling pathways. In this review, we describe the regulatory role of microRNAs of cancer cell glucose metabolism, including in the glucose uptake, glycolysis, tricarboxylic acid cycle and several signaling pathways and further suggest that microRNA-based therapeutics can be used to inhibit the process of glucose metabolism reprogramming in cancer cells and thus suppressing cancer progression.

CircRNA_104889 promotes lung adenocarcinoma cell invasion via sponging miR4458

Background

Lung adenocarcinoma is metastatic cancer with a high mortality rate. Circular RNAs (circRNAs) are a type of noncoding RNA and play a vital role in cancer progression. However, the expression and function of circRNAs in lung adenocarcinoma are still mostly unknown.

Methods

In this study, we screened the differential expression of circRNAs in human bronchial epithelial cells (HBE) and A549 human lung adenocarcinoma cell line (A549) by human circRNA microarray and RT-qPCR. The role of overexpressed circRNA_104889 in A549 cell proliferation, apoptosis, migration, and invasion was studied extensively. Intracellular localization of circRNA_104889 was visualized by FISH assay. MiRNA sponging, ERK1/2 signaling, and caspase-3 expression were analyzed in siRNA-mediated circRNA_104889 knockdowned A549 cells.

Results

CircRNA microarray showed overexpression of circRNA_104889 (> 13-fold) in A459 cells compared to HBE. This finding was further corroborated by the RT-qPCR result. CircRNA_104889 was mainly localized in the cytoplasm of A549 cells. The knockdown of circRNA_104889 in A549 cells by si-RNA mediated RNA interference did not affect cell proliferation and apoptosis but significantly inhibited cell migration and invasion in vitro. Furthermore, knockdown of circRNA_104889 led to an increase of miR4458 expression. Overexpression of miR4458 inhibited A549 cell migration. Both the knockdown of circRNA_104889 and overexpression of miR4458 inhibited the caspase-3 expression and ERK1/2 phosphorylation in A549 cells.

Conclusions

CircRNA_104889 promotes lung adenocarcinoma cell migration and invasion by sponging miR4458 and targeting ERK1/2 signaling and caspase-3 expression.

Circular RNA PRMT5 confers cisplatin-resistance via miR-4458/REV3L axis in non-small-cell lung cancer

Multifactor and multistep processes were elucidated to participate in the progression of non-small-cell lung cancer (NSCLC). Circular RNA 0031250 (circ-PRMT5) was a vital factor in NSCLC. However, the role of circ-PRMT5 in cisplatin (DDP)-resistance needed to be further highlighted. Expression profiles of circ-PRMT5, microRNA (miR)-4458, and EV3-like DNA-directed polymerase ζ catalytic subunit (REV3L) were detected using quantitative real-time polymerase chain reaction. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, and transwell assays were performed to determine the half-maximal inhibitory concentration of DDP, cell viability, apoptosis, and invasion in vitro. Besides, the protein levels of REV3L and indicated proteins were examined by adopting western blot. Dual-luciferase reporter assay was performed to analyze the interaction between miR-4458 and circ-PRMT5 or REV3L. The functional role of circ-PRMT5 was explored using a xenograft tumor model. Levels of circ-PRMT5 and REV3L were markedly increased, while miR-4458 was downregulated in resistant tissues and cells. Knockdown of circ-PRMT5 enhanced cell apoptosis, DDP-sensitivity, and declined metastasis in NSCLC with DDP resistance. Besides, miR-4458 inhibition or REV3L upregulation could revert circ-PRMT5 absence-mediated effect on DDP-sensitivity in vitro. Mechanically, circ-PRMT5 was a sponge of miR-4458 to regulate REV3L. Importantly, circ-PRMT5 silencing could interact with DDP treatment expedite the decrease of tumor growth in vivo. Circ-PRMT5 promoted DDP resistance via REV3L by sponging miR-4458 in NSCLC, thus providing a novel therapeutic strategy for patients with NSCLC.

Helicobacter pylori CagA Protein Attenuates 5-Fu Sensitivity of Gastric Cancer Cells Through Upregulating Cellular Glucose Metabolism

Introduction

Gastric cancer (GC) is one of the most malignancies leading to human mortality due to its development, progress, metastasis and poor prognosis, despite the development of remarkable chemotherapy and surgery. The 5-fluorouracil (5-Fu) is an effective anti-gastric cancer agent. However, a fraction of GC patients acquire 5-Fu chemoresistance.

Methods

In this study, the CagA protein was detected from CagA-positive gastric cancer patients by qRT-PCR and immunohistochemistry. The 5-Fu resistant gastric cancer cell line was generated from MKN45-CagA cells which was transfected with CagA overexpression vector. Cellular glucose metabolism was determined by measurements of glucose uptake, lactate product and glycolysis enzymes.

Results

We report that the Helicobacter pylori (H. pylori)-secreted Cytotoxin-associated gene A (CagA) oncoprotein is positively correlated with 5-Fu resistance of gastric cancer. From totally 72 CagA-positive gastric cancer patients, CagA high-expressed patients showed more resistance to 5-Fu than CagA low-expressed patients. Moreover, statistical analysis revealed that CagA mRNA and protein expressions were significantly upregulated in 5-Fu resistant gastric cancer patients. We observed that CagA protein is upregulated in 5-Fu resistant gastric cancer cells compared with sensitive cells. Interestingly, cellular glucose metabolism was upregulated; the glucose uptake and lactate production were significantly higher in 5-Fu resistant gastric cancer cells. The Akt phosphorylation and expressions of glycolysis key enzymes, Hexokinase 2 and LDHA, were significantly upregulated in 5-Fu resistant gastric cancer cells. On the other way, inhibition of glycolysis or Akt pathway effectively overcame 5-Fu resistance from both in vitro and in vivo models. Finally, we report that the combination of Akt or glycolysis inhibitor with 5-Fu could synergistically enhance the cytotoxicity of 5-Fu to CagA-overexpressed gastric cancer cells.

Discussion

In summary, our study demonstrated a CagA-Akt-glycolysis-5-Fu resistance axis, contributing to the development of new therapeutic agents against chemoresistant human gastric cancer.

Noncoding RNAs: the shot callers in tumor immune escape

Immunotherapy, designed to exploit the functions of the host immune system against tumors, has shown considerable potential against several malignancies. However, the utility of immunotherapy is heavily limited due to the low response rate and various side effects in the clinical setting. Immune escape of tumor cells may be a critical reason for such low response rates. Noncoding RNAs (ncRNAs) have been identified as key regulatory factors in tumors and the immune system. Consequently, ncRNAs show promise as targets to improve the efficacy of immunotherapy in tumors. However, the relationship between ncRNAs and tumor immune escape (TIE) has not yet been comprehensively summarized. In this review, we provide a detailed account of the current knowledge on ncRNAs associated with TIE and their potential roles in tumor growth and survival mechanisms. This review bridges the gap between ncRNAs and TIE and broadens our understanding of their relationship, providing new insights and strategies to improve immunotherapy response rates by specifically targeting the ncRNAs involved in TIE.

miR-4458 inhibits the epithelial-mesenchymal transition of hepatocellular carcinoma cells by suppressing the TGF-β signaling pathway via targeting TGFBR1

Hepatocellular carcinoma (HCC) is one of the most lethal cancers in the world. MicroRNAs play a pivotal role in the progression of various cancers. To date, very little attention has been paid to miR-4458. Therefore, the aim of our study was to explore the function and underlying molecular mechanism of miR-4458 in HCC. We found that the expression of miR-4458 was reduced in HCC tissues and cell lines. Forced overexpression of miR-4458 inhibited the migration, invasion, and epithelial-mesenchymal transition (EMT) of HCC cells, while downregulation of miR-4458 promoted the aggressive phenotype. Furthermore, transforming growth factor beta receptor 1 (TGFBR1), the modulator of the TGF-β signaling pathway, was verified to be a novel target gene of miR-4458 by dual-luciferase reporter gene assay. Upregulated miR-4458 dramatically abolished TGFBR1 and p-Smad2/3 expression, thus blocking the TGF-β signaling pathway. Moreover, restoration of TGFBR1 partially rescued the miR-4458-mediated suppressive effect on the migration, invasion, and EMT and reactivated the TGF-β signaling pathway in HCC cells. In summary, our findings first demonstrated a mechanism of miR-4458 in HCC cell migration, invasion, and EMT by regulating the TGF-β signaling pathway via directly targeting TGFBR1.

Effect of glycolysis inhibition by miR-448 on glioma radiosensitivity

OBJECTIVE

Although glucose metabolism reengineering is a typical feature of various tumors, including glioma, key regulators of glycolytic reprogramming are still poorly understood. The authors sought to investigate whether glycolysis inhibition by microRNA (miR)-448 increases radiosensitivity in glioma cells.

METHODS

The authors used glioma tissue samples from glioma patients, cells from glioblastoma (GBM) cell lines and normal human astrocyte cells, and subcutaneous tumor-bearing U87 cells in mice to examine the effects of signaling regulation by miR-448 in the response of glioma tissues and cells to radiation treatment. Techniques used for investigation included bioinformatics analyses, biochemical assays, luciferase reporter assays, and establishment of subcutaneous tumors in a mouse model. Glucose consumption, LDH activity, and cellular ATP were measured to determine the ability of glioma cells to perform glycolysis. Expression of HIF-1α was measured as a potential target gene of miR-448 in glycolysis.

RESULTS

miR-448 was detected and determined to be significantly downregulated in both glioma tissues from glioma patients and GBM cell lines. Furthermore, miR-448 acted as a tumor-inhibiting factor and suppressed glycolysis in glioma by negatively regulating the activity of HIF-1α signaling and then interfering with its downstream regulators relative to glycolysis, HK1, HK2, and LDHA. Interestingly, overexpression of miR-448 increased the x-radiation sensitivity of glioma cells. Finally, in in vivo experiments, subcutaneous tumor-bearing U87 cells in a mouse model verified that high expression of miR-448 also enhanced glioma radiosensitivity via inhibiting glycolytic factors.

CONCLUSIONS

miR-448 can promote radiosensitivity by inhibiting HIF-1α signaling and then negatively controlling the glycolysis process in glioma. A newly identified miR-448-HIF-1α axis acts as a potentially valuable therapeutic target that may be useful in overcoming radioresistance in glioma treatment.

MiR-4458/human antigen R (HuR) modulates PBX3 mRNA stability in melanoma tumorigenesis

Melanoma, a malignancy of the melanocyte, is characterized as the most fatal skin cancer with an increasing incidence. Of note, in spite of great attempts made for better treatment, the therapeutic outcome is barely satisfactory. Abnormal expression of microRNAs (miRNAs) acting as oncogenes or tumor suppressor genes, is frequently implicated in multiple human cancers, including melanoma. Here, we found that miRNA-4458, a reportedly tumor-suppressive miRNA in several cancers, was downregulated in melanoma cells. Besides, our findings indicated that microRNA-4458 (miR-4458) hindered cell proliferation and migration, yet induced apoptosis in melanoma. Mechanical interaction of miR-4458 and PBX3 mRNA, thereby inhibiting PBX3 expression in melanoma cells, was also presented in this work. Human antigen R (HuR) was reported to be greatly upregulated in diverse cancers and HuR-dependent stabilization of target gene contributed a lot to tumor progression. In this study, it revealed the stabilization of PBX3 mRNA by HuR, thereby boosting PBX3 expression. Lastly, we concluded that miR-4458 and HuR modulated the expression of PBX3 in a competitive manner in melanoma tumorigenesis, which might yield a novel insight into the molecular pathogenesis of melanoma.

Regulatory Role of Hexokinase 2 in Modulating Head and Neck Tumorigenesis

To support great demand of cell growth, cancer cells preferentially obtain energy and biomacromolecules by glycolysis over mitochondrial oxidative phosphorylation (OxPhos). Among all glycolytic enzymes, hexokinase (HK), a rate-limiting enzyme at the first step of glycolysis to catalyze cellular glucose into glucose-6-phosphate, is herein emphasized. Four HK isoforms, HK1-HK4, were discovered in nature. It was shown that HK2 expression is enriched in many tumor cells and correlated with poorer survival rates in most neoplastic cells. HK2-mediated regulations for cell malignancy and mechanistic cues in regulating head and neck tumorigenesis, however, are not fully elucidated. Cellular malignancy index, such as cell growth, cellular motility, and treatment sensitivity, and molecular alterations were determined in HK2-deficient head and neck squamous cell carcinoma (HNSCC) cells. By using various cancer databases, HK2, but not HK1, positively correlates with HNSCC progression in a stage-dependent manner. A high HK2 expression was detected in head and neck cancerous tissues compared with their normal counterparts, both in mouse and human subjects. Loss of HK2 in HNSCC cells resulted in reduced cell (in vitro) and tumor (in vivo) growth, as well as decreased epithelial-mesenchymal transition–mediated cell movement; in contrast, HK2-deficient HNSCC cells exhibited greater sensitivity to chemotherapeutic drugs cisplatin and 5-fluorouracil but are more resistant to photodynamic therapy, indicating that HK2 expression could selectively define treatment sensitivity in HNSCC cells. At the molecular level, it was found that HK2 alteration drove metabolic reprogramming toward OxPhos and modulated oncogenic Akt and mutant TP53-mediated signals in HNSCC cells. In summary, the present study showed that HK2 suppression could lessen HNSCC oncogenicity and modulate therapeutic sensitivity, thereby being an ideal therapeutic target for HNSCCs.

miR-4458 directly targets IGF1R to inhibit cell proliferation and promote apoptosis in hemangioma

Hemangiomas (HAs) are benign neoplasms of the vasculature. MicroRNA-4458 (miR-4458) has been reported to function as a tumor suppressor in multiple malignancies, but its biological function in HAs remains unknown. In the present study, the potential role of miR-4458 in HA-derived endothelial cells (HDECs) was investigated. Firstly, reverse-transcription-quantitative PCR analysis was used to confirm the expression of miR-4458 in HDECs following transfection with miR-4458 mimics or inhibitor. Subsequently, MTT and EdU assays were performed and subsequently determined that miR-4458 overexpression significantly inhibited proliferation, and knockdown promoted cell proliferation in HDECs. Flow cytometry analysis revealed that miR-4458 overexpression induced cell cycle arrest, whereas knockdown reversed G0/G1 phase arrest and apoptosis. Furthermore, insulin-like growth factor 1 receptor (IGF1R) was identified as a target of miR-4458. IGF1R knockdown enhanced the effects of miR-4458 on cell proliferation, cell cycle G0/G1 phase arrest and apoptosis in HDECs. Taken together, the results revealed that miR-4458 targeting of IGF1R may serve as a novel therapeutic strategy for treating patients with HAs.

Unlocking the Potential of HK2 in Cancer Metabolism and Therapeutics

Glycolysis is a tightly regulated process in which several enzymes, such as Hexokinases (HKs), play crucial roles. Cancer cells are characterized by specific expression levels of several isoenzymes in different metabolic pathways and these features offer possibilities for therapeutic interventions. Overexpression of HKs (mostly of the HK2 isoform) have been consistently reported in numerous types of cancer. Moreover, deletion of HK2 has been shown to decrease cancer cell proliferation without explicit side effects in animal models, which suggests that targeting HK2 is a viable strategy for cancer therapy. HK2 inhibition causes a substantial decrease of glycolysis that affects multiple pathways of central metabolism and also destabilizes the mitochondrial outer membrane, ultimately enhancing cell death. Although glycolysis inhibition has met limited success, partly due to low selectivity for specific isoforms and excessive side effects of the reported HK inhibitors, there is ample ground for progress. The current review is focused on HK2 inhibition, envisaging the development of potent and selective anticancer agents. The information on function, expression, and activity of HKs is presented, along with their structures, known inhibitors, and reported effects of HK2 ablation/inhibition. The structural features of the different isozymes are discussed, aiming to stimulate a more rational approach to the design of selective HK2 inhibitors with appropriate drug-like properties. Particular attention is dedicated to a structural and sequence comparison of the structurally similar HK1 and HK2 isoforms, aiming to unveil differences that could be explored therapeutically. Finally, several additional catalytic- and non-catalytic roles on different pathways and diseases, recently attributed to HK2, are reviewed and their implications briefly discussed.

NRF1-enhanced miR-4458 alleviates cardiac hypertrophy through releasing TTP-inhibited TFAM

Growing evidence suggests the crucial role of microRNAs (miRNAs) in regulating basic cell functions, and therefore participating in the pathologic development of diverse human diseases, including cardiac hypertrophy. Herein, we explained that miR-4458 was distinctly stimulated in Ang II-stimulated hypertrophic H9c2 cells. Intriguingly, miR-4458 inhibition led to exacerbated hypertrophic phenotypes in Ang II-treated H9c2 cells. In addition, the compensatory upregulation of miR-4458 in Ang II-treated H9c2 cells was ascribed to its transcriptional enhancement by NRF1, a transcription factor previously identified to be activated in early cardiac hypertrophy. Moreover, we discovered that miR-4458 served as a negative modulator in cardiac hypertrophy by prompting TFAM, a well-recognized myocardial protective protein. TTP, a RBP that always leads to degradation of recognized mRNAs, was predicted to interact with both miR-4458 and TFAM mRNA. Importantly, we verified that miR-4458 facilitated TFAM expression in cardiomyocytes by directly targeting TTP and releasing TTP-destabilized TFAM mRNA. On the whole, these findings demonstrated that NRF1-induced miR-4458 boosted TFAM via targeting TTP to dampen the exacerbation of cardiac hypertrophy, which indicates miR-4458 as a promising biomarker for the cardiac hypertrophy treatment.

The enhancement of glycolysis regulates pancreatic cancer metastasis

Pancreatic ductal adenocarcinoma is prone to distant metastasis and is expected to become the second leading cause of cancer-related death. In an extremely nutrient-deficient and hypoxic environment resulting from uncontrolled growth, vascular disturbances and desmoplastic reactions, pancreatic cancer cells utilize "metabolic reprogramming" to satisfy their energy demand and support malignant behaviors such as metastasis. Notably, pancreatic cancer cells show extensive enhancement of glycolysis, including glycolytic enzyme overexpression and increased lactate production, and this is caused by mitochondrial dysfunction, cancer driver genes, specific transcription factors, a hypoxic tumor microenvironment and stromal cells, such as cancer-associated fibroblasts and tumor-associated macrophages. The metabolic switch from oxidative phosphorylation to glycolysis in pancreatic cancer cells regulates the invasion-metastasis cascade by promoting epithelial-mesenchymal transition, tumor angiogenesis and the metastatic colonization of distant organs. In addition to aerobic glycolysis, oxidative phosphorylation also plays a critical role in pancreatic cancer metastasis in ways that remain unclear. In this review, we expound on the intracellular and extracellular causes of the enhancement of glycolysis in pancreatic cancer and the strong association between glycolysis and cancer metastasis, which we expect will yield new therapeutic approaches targeting cancer metabolism.

MiR-4458 inhibits breast cancer cell growth, migration, and invasiveness by targeting CPSF4

Numerous studies have reported that CPSF4 is over-expressed in a large percentage of human lung cancers, and CPSF4 has been identified as a potential oncogene of human lung tumor. Downregulation of CPSF4 inhibits the proliferation and promotes the apoptosis of lung adenocarcinoma cells. A previous study by our group also found overexpression of CPSF4 in breast cancer (BC), and was closely associated with a poor prognosis for the patient. This study investigates microRNAs (miRNAs) that target CPSF4 to modulate BC cell proliferation. We found that miR-4458 was noticeably reduced in BC tissues and cells. Using a miR-4458 mimic, we found that cell proliferation, migration, and invasiveness were suppressed by miR-4458 overexpression, and were enhanced by reducing the expression of miR-4458. Moreover, the results from bioinformatics analyses suggest a putative target site in the CPSF4 3'-UTR. Furthermore, using luciferase reporter assays and Western blotting, we verified that miR-4458 directly targets the 3'-UTR of CPSF4 and downregulates COX-2 and h-TERT, which are downstream target genes of CPSF4. Additionally, PI3K/AKT and ERK were shown to be inhibited by miR-4458 overexpression in BC cells. Moreover, miR-4458 suppresses BC cell growth in vivo. Consequently, these results suggest that the miR-4458-CPSF4-COX-2-hTERT axis might serve as a potential target for the treatment of BC patients.

Potential regulation by miRNAs on glucose metabolism in liver of common carp (Cyprinus carpio) at different temperatures

Water temperature can affect the metabolism of fish. Common carp (Cyprinus carpio) is a representative eurythermic fish that can survive at a wide range of ambient temperatures, allowing it to live in an extensive geographical range. The goal of this work was to study the glucose metabolism of common carp at different temperatures and determine the miRNAs involved in the regulation of glucose metabolism. We determined the indicators related to glucose metabolism after long-term temperature stress and constructed nine small RNA libraries of livers under different temperature stress (5 °C, 17 °C, and 30 °C, with three biological replicates for each temperature), and subjected these samples to high-throughput sequencing. A positive relationship was observed between weight gain rate (WGR) and temperature increase after 18 days of temperature stress. However, the glucose level in the plasma maintained a gentle decrease. Unexpectedly, liver lactic acid levels were elevated in HTG (high temperature group) and LTG (low temperature group). Six down-regulated miRNAs (miR-122, miR-30b, miR-15b-5p, miR-20a-5p, miR-1, and miR-7b) were identified as involved in the regulation of glycolysis. Twelve genes were predicted as targets of these miRNAs, and these genes are in pathways related to pyruvate metabolism, glycolysis/gluconeogenesis, and the citrate cycle (TCA cycle). The results allowed prediction of a potential regulatory network of miRNAs involved in the regulation of glycolysis. The target genes of six down-regulated miRNAs were up-regulated under temperature stress, including Aldolase C, fructose-bisphosphate, b (ALDOCB), multiple inositol-polyphosphate phosphatase 1 (MINPP1), phosphoenolpyruvate carboxykinase 1 (PCK1), pyruvate dehydrogenase E1 alpha 1 (PDHA1), aldehyde dehydrogenase 9 family member A1a (ALDH9A1A), Acetyl-coenzyme A synthetase (ACSS), lactate dehydrogenase b (LDH-b), and glyoxylate reductase/hydroxypyruvate reductase (GRHPR). Other key genes of glycolysis, glucose transporter 1 (GLUT-1), pyruvate kinase PKM (PKM), and mitochondrial pyruvate carrier (MPC) were significantly up-regulated in LTG and HTG. Overall, the results suggest that miRNAs maintain their energy requirements by regulating glycolysis and play an important role in the molecular response to cold and heat stress of common carp. These data provide the foundation for further studies of the role of miRNAs in environmental adaptation in fish.

LncRNA KCNQ1OT1 acting as a ceRNA for miR-4458 enhances osteosarcoma progression by regulating CCND2 expression

Osteosarcoma is prevalent worldwide and characterized as a challenging health burden. It has been increasingly indicated that long non-coding RNAs (lncRNAs) are significant in pathological processes of numerous cancers, exerting oncogenic or tumor-suppressive function. However, the participation of KCNQ1OT1 in osteosarcoma has not been elaborated. In this study, we focus on interrogating the function of KCNQ1OT1 and its underlying mechanism in osteosarcoma. Our work demonstrated the upregulation of KCNQ1OT1 in osteosarcoma through qRT-PCR. Besides, loss of function assay (CCK-8, transwell migration) indicated KCNQ1OT1 promoted cell proliferation, migration in osteosarcoma. Mechanically, KCNQ1OT1 acting as sponge for miR-4458 antagonized its tumor-suppressive impact on CCND2 expression. The anti-apoptotic nature of KCNQ1OT1 was also unveiled via caspase-3 activity assay. Overexpressed KCNQ1OT1 acted as competing endogenous RNA (ceRNA) for miR-4458 and subsequently reinforced target gene CCND2. Collectively, the results of rescue experiments suggested that the oncogenic role of KCNQ1OT1 was performed through sponging miR-4458 and upregulating CCND2 during osteosarcoma development, providing a novel perspective of intervention in osteosarcoma management.

Micromanaging aerobic respiration and glycolysis in cancer cells

BACKGROUND

Cancer cells possess a common metabolic phenotype, rewiring their metabolic pathways from mitochondrial oxidative phosphorylation to aerobic glycolysis and anabolic circuits, to support the energetic and biosynthetic requirements of continuous proliferation and migration. While, over the past decade, molecular and cellular studies have clearly highlighted the association of oncogenes and tumor suppressors with cancer-associated glycolysis, more recent attention has focused on the role of microRNAs (miRNAs) in mediating this metabolic shift. Accumulating studies have connected aberrant expression of miRNAs with direct and indirect regulation of aerobic glycolysis and associated pathways.

SCOPE OF REVIEW

This review discusses the underlying mechanisms of metabolic reprogramming in cancer cells and provides arguments that the earlier paradigm of cancer glycolysis needs to be updated to a broader concept, which involves interconnecting biological pathways that include miRNA-mediated regulation of metabolism. For these reasons and in light of recent knowledge, we illustrate the relationships between metabolic pathways in cancer cells. We further summarize our current understanding of the interplay between miRNAs and these metabolic pathways. This review aims to highlight important metabolism-associated molecular components in the hunt for selective preventive and therapeutic treatments.

MAJOR CONCLUSIONS

Metabolism in cancer cells is influenced by driver mutations but is also regulated by posttranscriptional gene silencing. Understanding the nuanced regulation of gene expression in these cells and distinguishing rapid cellular responses from chronic adaptive mechanisms provides a basis for rational drug design and novel therapeutic strategies.

Tristetraprolin-mediated hexokinase 2 expression regulation contributes to glycolysis in cancer cells

Hexokinase 2 (HK2) catalyzes the first step of glycolysis and is up-regulated in cancer cells. The mechanism has not been fully elucidated. Tristetraprolin (TTP) is an AU-rich element (ARE)-binding protein that inhibits the expression of ARE-containing genes by enhancing mRNA degradation. TTP expression is down-regulated in cancer cells. We demonstrated that TTP is critical for down-regulation of HK2 expression in cancer cells. HK2 mRNA contains an ARE within its 3'-UTR. TTP binds to HK2 3'-UTR and enhances degradation of HK2 mRNA. TTP overexpression decreased HK2 expression and suppressed the glycolytic capacity of cancer cells, measured as glucose uptake and production of glucose-6-phosphate, pyruvate, and lactate. TTP overexpression reduced both the extracellular acidification rate (ECAR) and the oxygen consumption rate (OCR) of cancer cells. Ectopic expression of HK2 in cancer cells attenuated the reduction in glycolytic capacity, ECAR, and OCR from TTP. Taken together, these findings suggest that TTP acts as a negative regulator of HK2 expression and glucose metabolism in cancer cells.

MicroRNA-4458 suppresses migration and epithelial-mesenchymal transition via targeting HMGA1 in non-small-cell lung cancer cells

Purpose

Increasing studies have shown that microRNA-4458 (miR-4458) is associated with human cancer progression. However, the molecular mechanism of miR-4458 in non-small-cell lung cancer (NSCLC) remains largely unknown. This study aims to reveal the biological function of miR-4458 in NSCLC.

Materials and methods

The expression of miR-4458 in NSCLC cells was evaluated by qRT-PCR. Cell proliferation and migration assay were carried out in vitro after transfection. A luciferase reporter and Western blot assay were performed to identify the functional target of miR-4458.

Results

The study indicated that miR-4458 was markedly downregulated in NSCLC cells. Overexpression of miR-4458 strongly reduced the proliferation and migration in NSCLC cell lines. In addition, miR-4458 inhibited the progression of migration and epithelial–mesenchymal transition (EMT) through the PI3K/AKT pathway. Luciferase report assay demonstrated that HMGA1 was a target gene for miR-4458.

Conclusion

The results indicate that miR-4458 participated in the process of migration and EMT via directly targeting HMGA1 and miR-4458 might be a potential novel therapeutic target in NSCLC.

Up-regulated miR-29c inhibits cell proliferation and glycolysis by inhibiting SLC2A3 expression in prostate cancer

Prostate cancer (PCa) is the most commonly cancer in male worldwide. However, the molecular mechanisms underlying the progression of PCa remain unclear. MiR-29c was reported to be down-regulated in several kinds of tumors. Here, we for the first time demonstrated miR-29c was down-regulated in PCa samples. SLC2A3, a regulator of glycolysis, was validated as a direct target of miR-29c. Moreover, functional studies showed miR-29c could inhibit cell growth, induce apoptosis and deceased the rate of glucose metabolism. Accordingly, we identified miR-29c acted as a tumor-suppressor and was down-regulated in PCa. We thought this study will provide useful information to explore the potential candidate biomarkers for diagnosis and prognosis targets of PCa.

Effect of ganoderic acid D on colon cancer Warburg effect: Role of SIRT3/cyclophilin D

Ganoderic acid D (GAD) is a highly oxygenated tetracyclic triterpenoid. This study aims to assess the effects of GAD on the energy metabolism of colon cancer through the regulation of SIRT3 expression and whether this effect is related to acetylated cyclophilin D. The results demonstrated that GAD inhibits the energy reprogramming of colon cancer cells including glucose uptake, lactate production, pyruvate and acetyl-coenzyme production in colon cancer cells. Meanwhile, GAD upregulated the protein expression of SIRT3. Furthermore, the interruption of SIRT3 expression significantly reversed all the effects of SIRT3 on the energy reprogramming of colon cancer. In addition, GAD induced the deacetylated cyclophilin D (CypD) by SIRT3, whereas SIRT3-shRNA inhibited its combining effect on CypD. The energy reprogramming effects of GAD on colon cancer seem to be mediated by SIRT3 upregulation via acetylated CypD inhibition.

MicroRNA-4458 suppresses the proliferation of human lung cancer cells in vitro by directly targeting Lin28B

Previous studies have shown that the expression of microRNA-4458 (miR-4458) is dysregulated in hepatocellular carcinoma and colon cancer. In this study, we investigated the direct target of miR-4458 and its biological functions in human lung cancer cells. By using the database TargetScan, we identified Lin28B, an oncogene, as a direct target gene of miR-4458. In dual-luciferase reporter assay, we found that miR-4458 mimics dose-dependently inhibited the luciferase activity of the wild-type 3'UTR of Lin28B in human lung cancer A549 and NCI-H1299 cell lines without affecting its mutant forms, whereas anti-miR-4458, an inhibitor of miR-4458, dose-dependently promoted the luciferase activity of the wild-type 3'UTR of Lin28B in A549 and NCI-H1299 cell lines without affecting its mutant forms. Overexpression of miR-4458 significantly decreased the protein levels of Lin28B in the cells, and inhibited the cell growth and colony formation. Conversely, knockdown of miR-4458 with anti-miR-4458 significantly increased the protein levels of Lin28B, and promoted the cell proliferation, which could be reverted by knockdown of Lin28B expression. In addition, we detected the expression of Lin28B using RT-PCR in 40 human lung cancer tissues and matched peritumoral tissues, and found that Lin28B was overexpressed in lung cancer tissues and negatively correlated with miR-4458 expression (r=-0.694, P<0.05). We conclude that miR-4458 is a tumor suppressor, and Lin28B is the direct target of miR-4458. These results suggest the modulation of miR-4458/Lin28B expression offers a potential therapeutic strategy for lung cancer.

MicroRNAs and altered metabolism of clear cell renal cell carcinoma: Potential role as aerobic glycolysis biomarkers

BACKGROUND

Warburg Effect is a metabolic switch that occurs in most of cancer cells but its advantages are not fully understood. This switch is known to happen in renal cell carcinoma (RCC), which is the most common solid cancer of the adult kidney. RCC carcinogenesis is related to pVHL loss and Hypoxia Inducible Factor (HIF) activation, ultimately leading to the activation of several genes related to glycolysis. MicroRNAs (miRNAs) regulate gene expression at a post-transcriptional level and are also deregulated in several cancers, including RCC.

SCOPE OF REVIEW

This review focuses in the miRNAs that direct target enzymes involved in glycolysis and that are deregulated in several cancers. It also reviews the possible application of miRNAs in the improvement of clinical patients' management.

MAJOR CONCLUSIONS

Several miRNAs that direct target enzymes involved in glycolysis are downregulated in cancer, strongly influencing the Warburg Effect. Due to this strong influence, FDG-PET can possibly benefit from measurement of these miRNAs. Restoring their levels can also bring an improvement to the current therapies.

GENERAL SIGNIFICANCE

Despite being known for almost a hundred years, the Warburg Effect is not fully understood. MiRNAs are now known to be intrinsically connected with this effect and present an opportunity to understand it. They also open a new door to improve current diagnosis and prognosis tests as well as to complement current therapies. This is urgent for cancers like RCC, mostly due to the lack of an efficient screening test for early relapse detection and follow-up and the development of resistance to current therapies.

MiR-1 suppresses tumor cell proliferation in colorectal cancer by inhibition of Smad3-mediated tumor glycolysis

Aberrant expression of microRNA (miR)-1 has been observed in many human malignancies. However, the function and underlying mechanism of miR-1 remains elusive. To address the specific role of miR-1 in tumor glycolysis using the gain- or loss-of-function studies. Metabolic studies combined with gene expression analysis were performed in vitro and in vivo. We demonstrated aberrant expression of miR-1 in aerobic glycolysis, the Warburg effect, in cancer cells. MiR-1 suppressed aerobic glycolysis and tumor cell proliferation via inactivation of Smad3 and targeting HIF-1α, leading to reduce HK2 and MCT4 expression, which illustrated a novel pathway to mediate aerobic glycolysis in cancer cells. Overexpression of miR-1 mimics significantly decreased tumor glycolysis, including lactate production and glucose uptake, and cell proliferation, and these effects were reversed by ectopic expression of Smad3. Importantly, endogenous Smad3 regulated and interacted with HIF-1α, resulting in increasing activity of Smad3, and this interaction was dramatically abolished by addition of miR-1. We further demonstrated that Smad3 was central to the effects of miR-1 in colorectal cancer cells, establishing a previously unappreciated mechanism by which the miR-1/Smad3/HIF-1α axis facilitates the Warburg effect to promote cancer progression in vitro and in vivo. The results indicate that miR-1 may have an essential role as a tumor suppressor, suggesting its potential role in molecular therapy of patients with advanced colorectal cancer.

MicroRNA-98 Suppress Warburg Effect by Targeting HK2 in Colon Cancer Cells

BACKGROUND

Warburg effect is a hallmark of cancer cells. Accumulating evidence suggests that microRNAs (miRs) could regulate such metabolic reprograming. Aberrant expression of miR-98 has been observed in many types of cancers. However, its functions and significance in colon cancer remain largely elusive.

AIMS

To investigate miR-98 expression and the biological functions in colon cancer progression.

METHODS

miR-98 expression levels were determined by quantitative RT-PCR in 215 cases of colon cancer samples. miR-98 mimic or inhibitor was used to test the biological functions in SW480 and HCT116 cells, followed by cell proliferation assay, lactate production, glucose uptake, and cellular ATP levels assay and extracellular acidification rates measurement. Western blot and luciferase assay were used to identify the target of miR-98.

RESULTS

miR-98 was significantly down-regulated in colon cancer tissues compared to adjacent colon tissues and acted as a suppressor for Warburg effect in cancer cells. miR-98 inhibited glycolysis by directly targeting hexokinase 2, or HK2, illustrating a novel pathway to mediate Warburg effect of cancer cells. In vitro experiments further indicated that HK2 was involved in miR-98-mediated suppression of glucose uptake, lactate production, and cell proliferation. In addition, we detected HK2 expression in colon cancer tissues and found that the expressions of miR-98 and HK2 were negatively correlated.

CONCLUSION

miR-98 acts as tumor suppressor gene and inhibits Warburg effect in colon cancer cells, which provided potential targets for clinical treatments.

Metabolic reprogramming and AMPKα1 pathway activation by caulerpin in colorectal cancer cells

Caulerpin, a secondary metabolite from the marine invasive green algae Caulerpa cylindracea is known to induce mitochondrial dysfunctions. In this study, the anticancer property of caulerpin was assessed in a panel of colorectal cancer cell lines. We demonstrated that caulerpin inhibited oxidative phosphorylation (OXPHOS) and facilitated an early intervention of the mitochondrial function, via inhibiting mitochondrial complex I, accompanied by the dissipation of mitochondrial membrane potential and a surge of reactive oxygen species (ROS) generation. Moreover, in response to the increment in AMP/ATP ratio, the energy sensor AMP-activated protein kinase (AMPK) was activated by caulerpin treatment in a calcium/calmodulin-dependent protein kinase 2 (CaMKK2)‑dependent manner. Distinguished effect on glycolysis was observed at different time-points after caulerpin treatment. Glycolysis was enhanced after a short time treatment with caulerpin, associated with upregulation of glucose transporter 1 (GLUT1), hexokinase II (HKII) and 6-phosphofructo-2-kinase (PFKFB3) protein expressions. However, long-term activation of AMPK by caulerpin damaged the glycolysis and glucose metabolism in colorectal cells, finally causing cell death. The persistent effect of caulerpin was mediated by AMPKα1, rather than AMPKα2, to abolish cell viability through hindering mTORC1-4E-BP1 axis. Moreover, caulerpin synergized with the glycolytic inhibitor 3BP in inhibiting cellular proliferation both in vitro and in vivo. Our findings on the previously uncharacterized anticancer effects of caulerpin may provide potential therapeutic approaches targeting the colorectal carcinoma metabolism.

Sexual Dimorphism and Aging in the Human Hyppocampus: Identification, Validation, and Impact of Differentially Expressed Genes by Factorial Microarray and Network Analysis

Motivation: In the brain of elderly-healthy individuals, the effects of sexual dimorphism and those due to normal aging appear overlapped. Discrimination of these two dimensions would powerfully contribute to a better understanding of the etiology of some neurodegenerative diseases, such as “sporadic” Alzheimer.

Methods: Following a system biology approach, top-down and bottom-up strategies were combined. First, public transcriptome data corresponding to the transition from adulthood to the aging stage in normal, human hippocampus were analyzed through an optimized microarray post-processing (Q-GDEMAR method) together with a proper experimental design (full factorial analysis). Second, the identified genes were placed in context by building compatible networks. The subsequent ontology analyses carried out on these networks clarify the main functionalities involved.

Results: Noticeably we could identify large sets of genes according to three groups: those that exclusively depend on the sex, those that exclusively depend on the age, and those that depend on the particular combinations of sex and age (interaction). The genes identified were validated against three independent sources (a proteomic study of aging, a senescence database, and a mitochondrial genetic database). We arrived to several new inferences about the biological functions compromised during aging in two ways: by taking into account the sex-independent effects of aging, and considering the interaction between age and sex where pertinent. In particular, we discuss the impact of our findings on the functions of mitochondria, autophagy, mitophagia, and microRNAs.

Conclusions: The evidence obtained herein supports the occurrence of significant neurobiological differences in the hippocampus, not only between adult and elderly individuals, but between old-healthy women and old-healthy men. Hence, to obtain realistic results in further analysis of the transition from the normal aging to incipient Alzheimer, the features derived from the sexual dimorphism in hippocampus should be explicitly considered.