The emerging roles of microRNAs in cancer metabolism

Unlocking melanoma Suppression: Insights from Plasma-Induced potent miRNAs through PI3K-AKT-ZEB1 axis

INTRODUCTION

Melanoma is a rare but highly malignant form of skin cancer. Although recent targeted and immune-based therapies have improved survival rates by 10-15%, effective melanoma treatment remains challenging. Therefore, novel, combinatorial therapy options such as non-thermal atmospheric pressure plasma (NTP) are being investigated to inhibit and prevent chemoresistance. Although several studies have reported the apoptotic and inhibitory effects of reactive oxygen species produced by NTP in the context of melanoma, the intricate molecular network that determines the role of microRNAs (miRNAs) in regulating NTP-mediated cell death remains unexplored.

OBJECTIVES

This study aimed to explore the molecular mechanisms and miRNA networks regulated by NTP-induced oxidative stress in melanoma cells.

METHODS

Melanoma cells were exposed to NTP and then subjected to high-throughput miRNA sequencing to identify NTP-regulated miRNAs. Various biological processes and underlying molecular mechanisms were assessed using Alamar Blue, propidium iodide (PI) uptake, cell migration, and clonogenic assays followed by qRT-PCR and flow cytometry.

RESULTS

NTP exposure for 3 min was sufficient to modulate the expression of several miRNAs, inhibiting cell growth. Persistent NTP exposure for 5 min increased differential miRNA regulation, PI uptake, and the expression of genes involved in cell cycle arrest and death. qPCR confirmed that miR-200b-3p and miR-215-5p upregulation contributed to decreased cell viability and migration. Mechanistically, inhibiting miR-200b-3p and miR-215-5p in SK-2 cells enhancedZEB1, PI3K, and AKT expression, increasing cell proliferation and viability.

CONCLUSION

This study demonstrated that NTP exposure for 5 min results in the differential regulation of miRNAs related to the PI3K-AKT-ZEB1 axis and cell cycle dysregulation to facilitate melanoma suppression.

Analysis of the Inhibitory Effect of hsa-miR-145-5p and hsa-miR-203a-5p on Imatinib-Resistant K562 Cells by GC/MS Metabolomics Method

Imatinib (IM) resistance is considered to be a significant challenge in the management of chronic myeloid leukemia (CML). Previous studies have reported that hsa-miR-145-5p and hsa-miR-203a-5p can overcome IM resistance and hsa-miR-203a-5p can alter glutathione metabolism in IM-resistant cells. The purpose of this study was to examine whether hsa-miR-145-5p or hsa-miR-203a-5p counters IM resistance by targeting the overall metabolic profile of IM-resistant K562 cells. The metablic profiling of cell lysates obtained from IM-sensitive, IM-resistant, and miR-transfected IM-resistant K562 cells was carried out using the GC-MS technique. Overall, 75 major metabolites were detected, of which 32 were present in all samples. The pathway analysis of MetaboAnalyst 5.0 revealed that the majorly enriched pathways included glucose metabolism, fatty acid biosynthesis, lipogenesis, and nucleotide metabolism. Eleven of identified metabolites, l-glutamine, l-glutamic acid, l-lactic acid, phosphoric acid, 9,12-octadecadienoic acid, 9-octadecenoic acid, myristic acid, palmitic acid, cholesterol, and β-alanine, appeared in enriched pathways. IM-resistant cells had comparatively higher concentrations of all of these metabolites. Notably, the introduction of hsa-miR-145-5p or hsa-miR-203a-5p into resistant cells resulted in a decrease in levels of these metabolites. The efficacy of miR-203a-5p was particularly remarkable in comparison with miR-145-5p, as evidenced by partial least-squares-discriminant analysis (PLS-DA), which showed a high level of similarity in metabolic profile between IM-sensitive K562 cells and IM-resistant cells transfected with hsa-miR-203a-5p. The results indicate that GC-MS-based metabolic profiling has the potential to distinguish between drug-resistant and -sensitive cells. This approach can also be used to routinely monitor therapeutic response in drug-resistant patients, thus, enabling personalized therapy.

Naringenin in combination with quercetin/fisetin shows synergistic anti-proliferative and migration reduction effects in breast cancer cell lines

INTRODUCTION & AIM

Breast cancer is one of the most common cancers with a high mortality rate among women worldwide. Quercetin/fisetin and naringenin, three well-known flavonoids, have been used to fight against various cancers. The aim of the present study was to investigate the possible synergism of quercetin/fisetin with naringenin on MCF7 and MDA-MB-231 breast cancer cell lines.

METHODS

In this study, cultured MCF7 and MDA-MB-231 cells were treated with different concentrations of quercetin/fisetin individually and in combination with naringenin. MTT assay and scratch assay was employed to determine cell viability and migration respectively. Real-time PCR was used to study the expression level of apoptosis genes and miR-1275 (tumor suppressor miRNA) and mir-27a-3p (oncogenic miRNA).

RESULTS

A synergism effect of quercetin/fisetin and naringenin (CI < 1) was observed for both cell lines. Combination therapies were significantly more effective in cell growth reduction, migration suppression and apoptosis induction than single therapies. Gene expression analysis revealed the upregulation of miR-1275 and downregulation miR-27a-3p.

CONCLUSION

Our results indicate that quercetin/fisetin enhances the anti-proliferative and anti-migratory activities in combination with naringenin in MCF7 and MDA-MB-231 human breast cancer cell lines. Therefore, the combination of Que/Fis and Nar can be proposed as a promising therapeutic strategy for further investigations.

MicroRNA‑153 may act as a potential biomarker and prognostic indicator of patients with gastric cancer

MicroRNA (miR/miRNA)-153, as a novel tumor-related miRNA, has been found to be aberrantly expressed in different types of cancer; however, to the best of our knowledge, the role of miR-153 in gastric cancer (GC) remains unclear. The present study demonstrated that miR-153 expression was markedly decreased in GC, including GC cell lines and culture medium, GC tissues, and serum samples, based on reverse transcription-quantitative PCR, and this was further confirmed by fluorescence in situ hybridization. Transfection with miR-153 mimics inhibited proliferation and migration, and promoted apoptosis in GC cells. The serum expression levels of miR-153 were decreased in 59 patients with GC compared with those of 9 healthy controls, and more decreased in advanced GC compared with early-stage GC, suggesting that miR-153 was associated with tumor progression. Furthermore, serum miR-153 was expressed at significantly lower levels in patients with GC with larger tumor size (≥4 cm; P=0.013), poor differentiation and signet histology (P=0.013), lymph node metastasis (P=0.025) and advanced tumor stage (TNM stage III and IV; P=0.048) compared with patients with a smaller tumor size (<4 cm), well and moderate differentiation, no lymph node metastasis, and TNM stage I and II, respectively. In conclusion, the present study revealed that low miR-153 expression was associated with poor prognosis in GC and miR-153 may potentially act as a tumor biomarker and therapeutic target in GC.

Decoding the regulatory roles of non-coding RNAs in cellular metabolism and disease

Non-coding RNAs, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), are being studied extensively in a variety of fields. Their roles in metabolism have received increasing attention in recent years but are not yet clear. The regulation of glucose, fatty acid, and amino acid metabolism is an imperative physiological process that occurs in living organisms and takes part in cancer and cardiovascular diseases. Here, we summarize the important roles played by non-coding RNAs in glucose metabolism, fatty acid metabolism, and amino acid metabolism, as well as the mechanisms involved. We also summarize the therapeutic advances for non-coding RNAs in diseases such as obesity, cardiovascular disease, and some metabolic diseases. Overall, non-coding RNAs are indispensable factors in metabolism and have a significant role in the three major metabolisms, which may be exploited as therapeutic targets in the future.

Sirtuin1-p53: a potential axis for cancer therapy

Sirtuin1 (SIRT1) is a conserved nicotinamide adenine dinucleotide (NAD⁺)-dependent histone deacetylase that plays key roles in a range of cellular events, including the maintenance of genome stability, gene regulation, cell proliferation, and apoptosis. P53 is one of the most studied tumor suppressors and the first identified non-histone target of SIRT1. SIRT1 deacetylates p53 in a NAD⁺-dependent manner and inhibits its transcriptional activity, thus exerting action on a series of pathways related to tissue homeostasis and various pathological states. The SIRT1-p53 axis is thought to play a central role in tumorigenesis. Although SIRT1 was initially identified as a tumor promoter, evidence now indicates that SIRT1 may also act as a tumor suppressor. This seemingly contradictory evidence indicates that the functionality of SIRT1 may be dictated by different cell types and intracellular localization patterns. In this review, we summarize recent evidence relating to the interactions between SIRT1 and p53 and discuss the relative roles of these two molecules with regards to cancer-associated cellular events. We also provide an overview of current knowledge of SIRT1-p53 signaling in tumorigenesis. Given the vital role of the SIRT1-p53 pathway, targeting this axis may provide promising strategies for the treatment of cancer.

MiR-495-3p regulates cell migration and invasion in papillary thyroid carcinoma

Background

Papillary thyroid carcinoma (PTC) is the most prevalent histotype of thyroid cancer and the presence of BRAFV600E mutation in these tumors is related to the malignancy and prognosis of the disease. In recent years attention has been focused on the role of microRNAs in the biology of PTC cells, especially in their role in the modulation of pathways related to tumorigenesis. DLK1-DIO3-derived miRNAs have been shown to play important roles in tumor context and are globally downregulated in PTC.

Methods

Based on a previous in silico target prediction and gene enrichment analysis, we identified miR-495-3p as the candidate with the highest tumor suppressor potential role in PTC among DLK1-DIO3-derived miRNAs. We used bioinformatics and an in vitro model of miR-495-3p overexpression to further understand the influence of this molecule on the tumorigenic processes of PTC.

Results

Overexpression of miR-495-3p impaired cell migration and invasion of PTC cells harboring the BRAFV600E mutation and affected the expression of targets predicted in the bioinformatic analysis, such as TGFB2, EREG and CCND1.

Conclusion

Overall, our results indicate that the loss of miR-495-3p expression during PTC development might play an important role in its progression.

Thioredoxin System and miR-21, miR-23a/b and let-7a as Potential Biomarkers for Brain Tumor Progression: Preliminary Case Data

BACKGROUND

The thioredoxin system and microRNAs (miRNAs) are potential targets for both cancer progression and treatment. However, the role of miRNAs and their relation with the expression profile of thioredoxin system in brain tumor progression remains unclear.

METHODS

In this study, we aimed to determine the expression profiles of redox components Trx-1, TrxR-1 and PRDX-1, and oncogenic miR-21, miR-23a/b and let-7a and oncosuppressor miR-125 in different brain tumor tissues and their association with increasing tumor grade. We studied Trx-1, TrxR-1, and PRDX-1 messenger RNA expression levels by quantitative real-time polymerase chain reaction and protein levels by Western blot and miR-23a, miR-23b, miR-125a, miR-21, and let-7a miRNA expression levels by quantitative real-time polymerase chain reaction in 16 glioma, 15 meningioma, 5 metastatic, and 2 benign tumor samples. We also examined Trx-1, TrxR-1, and PRDX-1 protein levels in serum samples of 36 patients with brain tumor and 37 healthy volunteers by enzyme-linked immunosorbent assay.

RESULTS

We found that Trx-1, TrxR-1, and PRDX-1 presented high messenger RNA expression but low protein expression in low-grade brain tumor tissues, whereas they showed higher protein expression in sera of patients with low-grade brain tumors. miR-23b, miR-21, miR-23a, and let-7a were highly expressed in low-grade brain tumor tissues and positively correlated with the increase in thioredoxin system activity.

CONCLUSIONS

Our findings showed that Trx-1, TrxR-1, miR-21, miR-23a/b, and let-7a might be used for brain tumor diagnosis in the clinic. Further prospective studies including molecular pathway analyses are required to validate the miRNA/Trx system regulatory axis in brain tumor progression.

Crosstalk between metabolic reprogramming and epigenetics in cancer: updates on mechanisms and therapeutic opportunities

Reversible, spatial, and temporal regulation of metabolic reprogramming and epigenetic homeostasis are prominent hallmarks of carcinogenesis. Cancer cells reprogram their metabolism to meet the high bioenergetic and biosynthetic demands for vigorous proliferation. Epigenetic dysregulation is a common feature of human cancers, which contributes to tumorigenesis and maintenance of the malignant phenotypes by regulating gene expression. The epigenome is sensitive to metabolic changes. Metabolism produces various metabolites that are substrates, cofactors, or inhibitors of epigenetic enzymes. Alterations in metabolic pathways and fluctuations in intermediate metabolites convey information regarding the intracellular metabolic status into the nucleus by modulating the activity of epigenetic enzymes and thus remodeling the epigenetic landscape, inducing transcriptional responses to heterogeneous metabolic requirements. Cancer metabolism is regulated by epigenetic machinery at both transcriptional and post‐transcriptional levels. Epigenetic modifiers, chromatin remodelers and non‐coding RNAs are integral contributors to the regulatory networks involved in cancer metabolism, facilitating malignant transformation. However, the significance of the close connection between metabolism and epigenetics in the context of cancer has not been fully deciphered. Thus, it will be constructive to summarize and update the emerging new evidence supporting this bidirectional crosstalk and deeply assess how the crosstalk between metabolic reprogramming and epigenetic abnormalities could be exploited to optimize treatment paradigms and establish new therapeutic options. In this review, we summarize the central mechanisms by which epigenetics and metabolism reciprocally modulate each other in cancer and elaborate upon and update the major contributions of the interplays between epigenetic aberrations and metabolic rewiring to cancer initiation and development. Finally, we highlight the potential therapeutic opportunities for hematological malignancies and solid tumors by targeting this epigenetic‐metabolic circuit. In summary, we endeavored to depict the current understanding of the coordination between these fundamental abnormalities more comprehensively and provide new perspectives for utilizing metabolic and epigenetic targets for cancer treatment.

Fructose-1,6-Bisphosphatase 2 Inhibits Oral Squamous Cell Carcinoma Tumorigenesis and Glucose Metabolism via Downregulation of c-Myc

Background

Fructose-1,6-bisphosphatase 2 (FBP2), known as a rate-limiting enzyme in gluconeogenesis, is a tumor suppressor downregulated in various cancers. However, the role of FBP2 in oral squamous cell carcinoma (OSCC) remains largely unclear.

Methods

The level of FBP2 in OSCC tissues and matched adjacent normal tissues was determined by western blot and RT-qPCR assays. In addition, analysis of FBP2 function in OSCC cells was assessed using both gain-of-function and loss-of-function studies.

Results

In this study, we found that the expression of FBP2 was remarkably downregulated in OSCC tissues and OSCC cells. Overexpression of FBP2 suppressed the viability, proliferation, migration, and glycolysis of OSCC cells, whereas FBP2 knockdown exhibited the opposite results. Moreover, downregulation of FBP2 promoted the growth and glycolysis of OSCC cells in nude mice in a xenograft model. Specifically, FBP2 colocalizes with the c-Myc transcription factor in the nucleus. Significantly, inhibitory effects of FBP2 overexpression on the viability, proliferation, migration, and glycolysis of OSCC cells were reversed by c-Myc overexpression.

Conclusion

Collectively, FBP2 could suppress the proliferation, migration and glycolysis in OSCC cells through downregulation of c-Myc. Our study revealed a FBP2-c-Myc signaling axis that regulates OSCC glycolysis and may provide a potential intervention strategy for OSCC treatment.

The role and mechanism of noncoding RNAs in regulation of metabolic reprogramming in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Metabolic reprogramming is considered to be an important hallmark of cancer. Emerging studies have demonstrated that noncoding RNAs (ncRNAs) are closely associated with metabolic reprogramming of HCC. NcRNAs can directly regulate the expressions or functions of metabolic enzymes or indirectly regulate the metabolism of HCC cells through some vital signaling pathways. Until now, the mechanisms of HCC development and progression remain largely unclear, and understanding the regulatory mechanism of ncRNAs on metabolic reprogramming of HCC may provide an important basis for breakthrough progress in the treatment of HCC. In this review, we summarize the ncRNAs involved in regulating metabolic reprogramming of HCC. Specifically, the regulatory roles of ncRNAs in glucose, lipid and amino acid metabolism are elaborated. In addition, we discuss the molecular mechanism of ncRNAs in regulation of metabolic reprogramming and possible therapeutic strategies that target the metabolism of cancer cells by modulating the expressions of specific ncRNAs.

Non-Canonical Splicing and Its Implications in Brain Physiology and Cancer

The advance of experimental and computational techniques has allowed us to highlight the existence of numerous different mechanisms of RNA maturation, which have been so far unknown. Besides canonical splicing, consisting of the removal of introns from pre-mRNA molecules, non-canonical splicing events may occur to further increase the regulatory and coding potential of the human genome. Among these, splicing of microexons, recursive splicing and biogenesis of circular and chimeric RNAs through back-splicing and trans-splicing processes, respectively, all contribute to expanding the repertoire of RNA transcripts with newly acquired regulatory functions. Interestingly, these non-canonical splicing events seem to occur more frequently in the central nervous system, affecting neuronal development and differentiation programs with important implications on brain physiology. Coherently, dysregulation of non-canonical RNA processing events is associated with brain disorders, including brain tumours. Herein, we summarize the current knowledge on molecular and regulatory mechanisms underlying canonical and non-canonical splicing events with particular emphasis on cis-acting elements and trans-acting factors that all together orchestrate splicing catalysis reactions and decisions. Lastly, we review the impact of non-canonical splicing on brain physiology and pathology and how unconventional splicing mechanisms may be targeted or exploited for novel therapeutic strategies in cancer.

Integrated multi-omics analysis reveals miR-20a as a regulator for metabolic colorectal cancer

Single-driver molecular events specific to the metabolic colorectal cancer (CRC) have not been clearly elucidated. Herein, we identified 12 functional miRNAs linked to activated metabolism by integrating multi-omics features in metabolic CRC. These miRNAs exhibited significantly enriched CRC driver miRNAs, significant impacts on CRC cell growth and significantly correlated metabolites. Importantly, miR-20a is minimally expressed in normal colorectal tissues but highly expressed in metabolic CRC, suggesting the potential therapeutic target. Bioinformatics analyses further revealed miR-20a as the most powerful determinant that regulates a cascade of dysregulated events, including Wnt signaling pathway, core enzymes involved in FA metabolism program and triacylglycerol abundances. In vitro assays demonstrated that elevated miR-20a up-regulated FA synthesis enzymes via Wnt/β-catenin signaling, and finally promoted proliferative and migration of metabolic CRC cells. Overall, our study revealed that miR-20a promoted progression of metabolic CRC by regulating FA metabolism and served as a potential target for preventing tumor metastasis.

Reprogramming Carbohydrate Metabolism in Cancer and Its Role in Regulating the Tumor Microenvironment

Altered metabolism has become an emerging feature of cancer cells impacting their proliferation and metastatic potential in myriad ways. Proliferating heterogeneous tumor cells are surrounded by other resident or infiltrating cells, along with extracellular matrix proteins, and other secretory factors constituting the tumor microenvironment. The diverse cell types of the tumor microenvironment exhibit different molecular signatures that are regulated at their genetic and epigenetic levels. The cancer cells elicit intricate crosstalks with these supporting cells, exchanging essential metabolites which support their anabolic processes and can promote their survival, proliferation, EMT, angiogenesis, metastasis and even therapeutic resistance. In this context, carbohydrate metabolism ensures constant energy supply being a central axis from which other metabolic and biosynthetic pathways including amino acid and lipid metabolism and pentose phosphate pathway are diverged. In contrast to normal cells, increased glycolytic flux is a distinguishing feature of the highly proliferative cancer cells, which supports them to adapt to a hypoxic environment and also protects them from oxidative stress. Such rewired metabolic properties are often a result of epigenetic alterations in the cancer cells, which are mediated by several factors including, DNA, histone and non-histone protein modifications and non-coding RNAs. Conversely, epigenetic landscapes of the cancer cells are also dictated by their diverse metabolomes. Altogether, this metabolic and epigenetic interplay has immense potential for the development of efficient anti-cancer therapeutic strategies. In this book chapter we emphasize upon the significance of reprogrammed carbohydrate metabolism in regulating the tumor microenvironment and cancer progression, with an aim to explore the different metabolic and epigenetic targets for better cancer treatment.

The miR-27a/FOXJ3 Axis Dysregulates Mitochondrial Homeostasis in Colorectal Cancer Cells

Simple Summary

Cellular and mitochondrial metabolism can be dysregulated during tumorigenesis. miR-27a plays a central role in redirecting cell metabolism in colorectal cancer. In this study, we searched for new miR-27a targets that could influence mitochondria and identified FOXJ3 a master regulator of mitochondrial biogenesis. We validated FOXJ3 as an miR-27a target in an in vitro cell model system that was genetically modified for miR-27a expression and showed that the miR-27a/FOXJ3 axis down-modulates mitochondrial biogenesis and regulates other members of the pathway. The miR-27a/FOXJ3 axis also influences mitochondrial dynamics, superoxide production, respiration capacity, and membrane potential. A mouse xenograft model confirmed that miR-27a downregulates FOXJ3 in vivo and a survey of the TCGA-COADREAD dataset supported the inverse relationship of FOXJ3 with miR-27a and the impact on mitochondrial biogenesis. The miR-27a/FOXJ3 axis is a major actor in regulating mitochondrial homeostasis, and its discovery may contribute to therapeutic strategies aimed at restraining tumor growth by targeting mitochondrial activities.

Abstract

miR-27a plays a driver role in rewiring tumor cell metabolism. We searched for new miR-27a targets that could affect mitochondria and identified FOXJ3, an apical factor of mitochondrial biogenesis. We analyzed FOXJ3 levels in an in vitro cell model system that was genetically modified for miR-27a expression and validated it as an miR-27a target. We showed that the miR-27a/FOXJ3 axis down-modulates mitochondrial biogenesis and other key members of the pathway, implying multiple levels of control. As assessed by specific markers, the miR-27a/FOXJ3 axis also dysregulates mitochondrial dynamics, resulting in fewer, short, and punctate organelles. Consistently, in high miR-27a-/low FOXJ3-expressing cells, mitochondria are functionally characterized by lower superoxide production, respiration capacity, and membrane potential, as evaluated by OCR assays and confocal microscopy. The analysis of a mouse xenograft model confirmed FOXJ3 as a target and suggested that the miR-27a/FOXJ3 axis affects mitochondrial abundance in vivo. A survey of the TCGA-COADREAD dataset supported the inverse relationship of FOXJ3 with miR-27a and reinforced cellular component organization or biogenesis as the most affected pathway. The miR-27a/FOXJ3 axis acts as a central hub in regulating mitochondrial homeostasis. Its discovery paves the way for new therapeutic strategies aimed at restraining tumor growth by targeting mitochondrial activities.

The Plasma Levels of hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-320c in Patients with Asthma, COPD and Asthma-COPD Overlap Syndrome (ACOS)

BACKGROUND

Bronchial Asthma (BA) and Chronic Obstructive Pulmonary Disease (COPD) are chronic airway inflammation diseases. In recent years, patients with signs of both BA and COPD have been assigned to a separate group as Asthma-COPD Overlap Syndrome (ACOS). Free-circulating plasma microRNAs are considered as potential biomarkers of pulmonary diseases, including BA, COPD and ACOS.

OBJECTIVE

This study aimed to investigate the expression level of free-circulating plasma microRNAs hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-320c in patients with BA, COPD and ACOS for the detection and validation of new microRNAs as biomarkers for chronic lung diseases.

METHODS

The relative expression levels of 720 microRNAs were evaluated by Real Time-Polymerase Chain Reaction (RT-PCR) in patients with COPD and BA. Three upregulated microRNAs (hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-320c) were selected for further study. The obtained data was analyzed using the microRNA PCR Array Data Analysis tool. The sensitivity and specificity were estimated using the area under the Receiver Operating Characteristics curve (ROC).

RESULTS

The expression level of free-circulating hsa-miR-19b-3p was decreased in the blood plasma of patients with BA and ACOS, and increased in patients with COPD. hsa-miR-125b-5p was downregulated in the blood plasma of patients with COPD, and upregulated in patients with BA and ACOS. hsa-miR-320c was downregulated in the blood plasma of patients with BA, and upregulated in patients with COPD and ACOS. The ROC curves of patients with BA for hsa-miR-19b-3p, patients with ACOS for hsa-miR-125b-5p and patients with COPD for hsa-miR-320c revealed the probability of them as valuable biomarkers with AUCs of 0.824, 0.825, and 0.855, respectively.

CONCLUSION

Our study revealed three promising biomarkers for the diagnosis of COPD, BA and ACOS.

MicroRNAs Regulate Metabolic Phenotypes During Multicellular Tumor Spheroids Progression

During tumor progression, cancer cells rewire their metabolism to face their bioenergetic demands. In recent years, microRNAs (miRNAs) have emerged as regulatory elements that inhibit the translation and stability of crucial mRNAs, some of them causing direct metabolic alterations in cancer. In this study, we investigated the relationship between miRNAs and their targets mRNAs that control metabolism, and how this fine-tuned regulation is diversified depending on the tumor stage. To do so, we implemented a paired analysis of RNA-seq and small RNA-seq in a breast cancer cell line (MCF7). The cell line was cultured in multicellular tumor spheroid (MCTS) and monoculture conditions. For MCTS, we selected two-time points during their development to recapitulate a proliferative and quiescent stage and contrast their miRNA and mRNA expression patterns associated with metabolism. As a result, we identified a set of new direct putative regulatory interactions between miRNAs and metabolic mRNAs representative for proliferative and quiescent stages. Notably, our study allows us to suggest that miR-3143 regulates the carbon metabolism by targeting hexokinase-2. Also, we found that the overexpression of several miRNAs could directly overturn the expression of mRNAs that control glycerophospholipid and N-Glycan metabolism. While this set of miRNAs downregulates their expression in the quiescent stage, the same set is upregulated in proliferative stages. This last finding suggests an additional metabolic switch of the above mentioned metabolic pathways between the quiescent and proliferative stages. Our results contribute to a better understanding of how miRNAs modulate the metabolic landscape in breast cancer MCTS, which eventually will help to design new strategies to mitigate cancer phenotype.

MicroRNA-Mediated Metabolic Shaping of the Tumor Microenvironment

The metabolism of cancer cells is generally very different from what is found in normal counterparts. However, in a tumor mass, the continuous crosstalk and competition for nutrients and oxygen among different cells lead to metabolic alterations, not only in cancer cells, but also in the different stromal and immune cells of the tumor microenvironment (TME), which are highly relevant for tumor progression. MicroRNAs (miRs) are small non-coding RNAs that silence their mRNA targets post-transcriptionally and are involved in numerous physiological cell functions as well as in the adaptation to stress situations. Importantly, miRs can also be released via extracellular vesicles (EVs) and, consequently, take part in the bidirectional communication between tumor and surrounding cells under stress conditions. Certain miRs are abundantly expressed in stromal and immune cells where they can regulate various metabolic pathways by directly suppressing enzymes or transporters as well as by controlling important regulators (such as transcription factors) of metabolic processes. In this review, we discuss how miRs can induce metabolic reprogramming in stromal (fibroblasts and adipocytes) and immune (macrophages and T cells) cells and, in turn, how the biology of the different cells present in the TME is able to change. Finally, we debate the rebound of miR-dependent metabolic alterations on tumor progression and their implications for cancer management.

ZHX2 inhibits SREBP1c-mediated de novo lipogenesis in hepatocellular carcinoma via miR-24-3p

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Lipogenesis has been considered as a critical player in HCC initiation and progression. However, the underlying mechanism is still not fully understood. Here, we identified zinc fingers and homeoboxes 2 (ZHX2), an HCC-associated tumor suppressor, as an important repressor of de novo lipogenesis. Ectopic expression of ZHX2 significantly inhibited de novo lipogenesis in HCC cells and decreased expression of FASN, ACL, ACC1, and SCD1. In accordance with this, ZHX2 was negatively associated with SREBP1c, the master regulator of de novo lipogenesis, in HCC cell lines and human specimens. Results from silencing and overexpression demonstrated that ZHX2 inhibited de novo lipogenesis and consequent HCC progression via repression of SREBP1c. Furthermore, treatment with the SREBP1c inhibitor fatostatin dampened the spontaneous formation of tumors in liver-specific Zhx2 knockout mice. Mechanistically, ZHX2 increased expression of miR-24-3p transcriptionally, which targeted SREBP1c and led to its degradation. In conclusion, our data suggest a novel mechanism through which ZHX2 suppresses HCC progression, which may provide a new strategy for the treatment of HCC. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Metabolic Escape Routes of Cancer Stem Cells and Therapeutic Opportunities

Although improvement in early diagnosis and treatment ameliorated life expectancy of cancer patients, metastatic disease still lacks effective therapeutic approaches. Resistance to anticancer therapies stems from the refractoriness of a subpopulation of cancer cells-termed cancer stem cells (CSCs)-which is endowed with tumor initiation and metastasis formation potential. CSCs are heterogeneous and diverge by phenotypic, functional and metabolic perspectives. Intrinsic as well as extrinsic stimuli dictated by the tumor microenvironment (TME)have critical roles in determining cell metabolic reprogramming from glycolytic toward an oxidative phenotype and vice versa, allowing cancer cells to thrive in adverse milieus. Crosstalk between cancer cells and the surrounding microenvironment occurs through the interchange of metabolites, miRNAs and exosomes that drive cancer cells metabolic adaptation. Herein, we identify the metabolic nodes of CSCs and discuss the latest advances in targeting metabolic demands of both CSCs and stromal cells with the scope of improving current therapies and preventing cancer progression.

miR-27a is a master regulator of metabolic reprogramming and chemoresistance in colorectal cancer

BACKGROUND

Metabolic reprogramming towards aerobic glycolysis in cancer supports unrestricted cell proliferation, survival and chemoresistance. The molecular bases of these processes are still undefined. Recent reports suggest crucial roles for microRNAs. Here, we provide new evidence of the implication of miR-27a in modulating colorectal cancer (CRC) metabolism and chemoresistance.

METHODS

A survey of miR-27a expression profile in TCGA-COAD dataset revealed that miR-27a-overexpressing CRCs are enriched in gene signatures of mitochondrial dysfunction, deregulated oxidative phosphorylation, mTOR activation and reduced chemosensitivity. The same pathways were analysed in cell lines in which we modified miR-27a levels. The response to chemotherapy was investigated in an independent cohort and cell lines.

RESULTS

miR-27a upregulation in vitro associated with impaired oxidative phosphorylation, overall mitochondrial activities and slight influence on glycolysis. miR-27a hampered AMPK, enhanced mTOR signalling and acted in concert with oncogenes and tumour cell metabolic regulators to force an aerobic glycolytic metabolism supporting biomass production, unrestricted growth and chemoresistance. This latter association was confirmed in our cohort of patients and cell lines.

CONCLUSIONS

We disclose an unprecedented role for miR-27a as a master regulator of cancer metabolism reprogramming that impinges on CRC response to chemotherapy, underscoring its theragnostic properties.

The Emerging Roles of miR-125b in Cancers

MicroRNAs (miRNAs) are endogenous, noncoding, single-stranded RNA molecules of 22 nucleotides in length. MiRNAs have both tumor-suppressive properties and oncogenic properties that can control critical processes in tumors. Mature miR-125b originates from miR-125b-1 and miR-125b-2 and leads to the degradation of target mRNAs or the inhibition of translation through binding to the 3′ untranslated regions (3′-UTR) of target mRNAs. Importantly, miR-125b is involved in regulating NF-κB, p53, PI3K/Akt/mTOR, ErbB2, Wnt, and another signaling pathways, thereby controlling cell proliferation, differentiation, metabolism, apoptosis, drug resistance and tumor immunity. This review aims to summarize the recent literature on the role of miR-125b in the regulation of tumorigenesis and to explore its potential clinical application in the diagnosis, prognosis and clinical treatment of tumors.

miRNAs as Influencers of Cell-Cell Communication in Tumor Microenvironment

microRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the posttranscriptional level, inducing the degradation of the target mRNA or translational repression. MiRNAs are involved in the control of a multiplicity of biological processes, and their absence or altered expression has been associated with a variety of human diseases, including cancer. Recently, extracellular miRNAs (ECmiRNAs) have been described as mediators of intercellular communication in multiple contexts, including tumor microenvironment. Cancer cells cooperate with stromal cells and elements of the extracellular matrix (ECM) to establish a comfortable niche to grow, to evade the immune system, and to expand. Within the tumor microenvironment, cells release ECmiRNAs and other factors in order to influence and hijack the physiological processes of surrounding cells, fostering tumor progression. Here, we discuss the role of miRNAs in the pathogenesis of multicomplex diseases, such as Alzheimer’s disease, obesity, and cancer, focusing on the contribution of both intracellular miRNAs, and of released ECmiRNAs in the establishment and development of cancer niche. We also review growing evidence suggesting the use of miRNAs as novel targets or potential tools for therapeutic applications.

Serum exosomal miR-122 as a potential diagnostic and prognostic biomarker of colorectal cancer with liver metastasis

Background: Liver is the most common site for metastatic spread of CRC at the time of diagnosis which leads to high mortality. This study aimed to identify novel circulating exosomal miRNAs as biomarkers of colorectal cancer (CRC) with liver metastasis (LM).

Materials and methods: Candidate miRNAs were selected through integrated analysis of Gene Expression Omnibus (GEO) database as well as clinical samples. Exosomes isolated from serum and cultured media were identified by using transmission electron microscopy (TEM) and western blot. The expression levels and diagnostic value of candidate miRNAs were further tested and validated through qRT-PCR and receiver operating characteristic curve (ROC) analysis. The association of candidate miRNA expressions with patients' prognosis was analyzed with logistic regression and Cox proportional hazards regression models.

Results: After integrated analysis of three GEO datasets and clinical samples, miR-122 was discovered to be remarkably overexpressed in tissues of CRC patients. Then we revealed that elevated serum miR-122 was tumor-derived by being packaged into exosomes. The expressions of serum exosomal miR-122 were significantly upregulated in CRC patients, especially in those with LM. Serum exosomal miR-122 expressions could differentiate CRC patients with LM from healthy controls and patients without LM with area under the ROC curve (AUC) of 0.89 and 0.81. Uni- and multivariate logistic regression showed that serum exosomal miR-122 was an independent prognostic indicator of CRC patients.

Conclusions: Serum exosomal miR-122 was a novel potential diagnostic and prognostic biomarker in CRC patients with LM.

The molecular mechanisms of LncRNA-correlated PKM2 in cancer metabolism

Reprogrammed metabolism is an important hallmark of cancer cells. Pyruvate kinase (PK) is one of the major rate-limiting enzymes in glucose metabolism. The M2 isoform of PK (PKM2), is considered to be an important marker of metabolic reprogramming and one of the key enzymes. Recently, through the continuous development of genome-wide analysis and functional studies, accumulating evidence has demonstrated that long non-coding RNAs (LncRNAs) play vital regulatory roles in cancer progression by acting as either potential oncogenes or tumor suppressors. Furthermore, several studies have shown that up-regulation of PKM2 in cancer tissues is associated with LncRNAs expression and patient survival. Thus, scientists have begun to unveil the mechanism of LncRNA-associated PKM2 in cancer metabolic progression. Based on these novel findings, in this mini-review, we summarize the detailed molecular mechanisms of LncRNA related to PKM2 in cancer metabolism. We expect that this work will promote a better understanding of the molecular mechanisms of PKM2, and provide a profound potential for targeting PKM2 to treat tumors.

Epigenetics of Bladder Cancer: Where Biomarkers and Therapeutic Targets Meet

Bladder cancer (BC) is the most common neoplasia of the urothelial tract. Due to its high incidence, prevalence, recurrence and mortality, it remains an unsolved clinical and social problem. The treatment of BC is challenging and, although immunotherapies have revealed potential benefit in a percentage of patients, it remains mostly an incurable disease at its advanced state. Epigenetic alterations, including aberrant DNA methylation, altered chromatin remodeling and deregulated expression of non-coding RNAs are common events in BC and can be driver events in BC pathogenesis. Accordingly, these epigenetic alterations are now being used as potential biomarkers for these disorders and are being envisioned as potential therapeutic targets for the future management of BC. In this review, we summarize the recent findings in these emerging and exciting new aspects paving the way for future clinical treatment of this disease.

miR-885-5p Negatively Regulates Warburg Effect by Silencing Hexokinase 2 in Liver Cancer

Growing tumor cells possess a distinct metabolic phenomenon that allows them to preferentially utilize glucose through aerobic glycolysis, which is referred to as the “Warburg effect.” Accumulating evidence suggests that microRNAs (miRNAs) could regulate such metabolic reprogramming. Our microarray analysis and quantitative real-time PCR validation revealed that miR-885-5p was strongly downregulated in hepatocellular carcinoma (HCC) tissues and cell lines. To investigate miR-885-5p’s biological functions in HCC progression, malignant phenotypes were analyzed in different types of hypoxic model and indicated that overexpression of miR-885-5p significantly inhibited HCC cell proliferation and migration and induced apoptosis in vitro and tumor growth in vivo. Subsequent investigations of whether miR-885-5p regulated the glycometabolic activity of cancer cells demonstrated that forced expression of miR-885-5p in SMMC-7721 cells significantly reduced glucose uptake and lactate production by repressing several key enzymes related to glycolysis. Particularly, miR-885-5p directly targets the 3′ UTR of hexokinase 2 (HK2), which is a key enzyme that catalyzes the irreversible first step of glycolysis and associates with poor patient outcomes. The miR-885-5p/HK2 axis strongly links aerobic glycolysis to carcinogenesis and may become a promising therapeutic target and prognostic predictor for HCC patients.

CircRNAs in cancer metabolism: a review

Altered energy metabolism is a hallmark of tumors aiming at supplying necessary nutrients for tumorigenesis and development. These redirected metabolic pathways associated with carbohydrate, lipid and amino acid are orchestrated not only by carcinogenic proteins but by non-coding RNAs. Among them, circular RNA (circRNA), as a kind of novel identified non-coding RNAs, has become the focus of attention. Through binding with corresponding microRNAs or directly contacting proteins, circRNA plays a primarily important role in regulating cellular metabolism. Herein, we analyze the emerging findings and select circRNAs contributing to mutant glycolysis, lipogenesis and lipolysis, glutam inolysis, and oxidative respiration to deepen the understanding about the cancer metabolic regulatory network. In addition, we also discuss the possibility of circRNAs exerting their functions via exosomes and cancer stem cells. Owing to their unique structures and wide impacts, circRNAs may help reap huge fruits in developing clinical treatments targeting cancer metabolism.

Molecular Characterization and Clinical Relevance of Metabolic Expression Subtypes in Human Cancers

Metabolic reprogramming provides critical information for clinical oncology. Using molecular data of 9,125 patient samples from The Cancer Genome Atlas, we identified tumor subtypes in 33 cancer types based on mRNA expression patterns of seven major metabolic processes and assessed their clinical relevance. Our metabolic expression subtypes correlated extensively with clinical outcome: subtypes with upregulated carbohydrate, nucleotide, and vitamin/cofactor metabolism most consistently correlated with worse prognosis, whereas subtypes with upregulated lipid metabolism showed the opposite. Metabolic subtypes correlated with diverse somatic drivers but exhibited effects convergent on cancer hallmark pathways and were modulated by highly recurrent master regulators across cancer types. As a proof-of-concept example, we demonstrated that knockdown of SNAI1 or RUNX1—master regulators of carbohydrate metabolic subtypes—modulates metabolic activity and drug sensitivity. Our study provides a system-level view of metabolic heterogeneity within and across cancer types and identifies pathway cross-talk, suggesting related prognostic, therapeutic, and predictive utility.

MicroRNA-195 as a prognostic factor for cancer survival outcome in China: a meta-analysis

Purpose

MicroRNA-195 is dysregulated in different kinds of cancers and plays a pivotal role in tumorigenesis. It may function as a prognostic biomarker for cancers. However, the results from articles were not consistent. This study was designed to validate the prognostic value of microRNA-195 in human tumors.

Methods

We conducted a detailed search on PubMed until December 31, 2018. The quality of these publications was assessed on the basis of a list of key reviews presented by PRISMA statement. The pooled hazard ratios (HR) and pooled odds ratios (OR) of each 95% confidence interval (95% CI) were calculated to assess the effect.

Results

This meta-analysis included 12 studies involving 940 cancer patients to assess the prognostic value of miR-195 in different solid tumors. The results showed that patients with high expression of miR-195 had favorable tumor-node-metastasis (late vs early: pooled OR =0.16, 95% CI: 0.11–0.22, P<0.001), lymph node metastasis (pooled OR =0.25, 95% CI: 0.18–0.35, P<0.001) and distant metastasis (pooled OR =0.26, 95% CI: 0.13–0.52, P<0.001). At the same time, high levels of miR-195 expression were closely correlated with better overall survival (pooled HR =0.46, 95% CI: 0.36–0.58, P<0.001).

Conclusion

Elevated microRNA-195 may serve as a potential biomarker to predict a favorable prognosis for various cancer types in China.

Hypoxia- and MicroRNA-Induced Metabolic Reprogramming of Tumor-Initiating Cells

Colorectal cancer (CRC), the second most common cause of cancer mortality in the Western world, is a highly heterogeneous disease that is driven by a rare subpopulation of tumorigenic cells, known as cancer stem cells (CSCs) or tumor-initiating cells (TICs). Over the past few years, a plethora of different approaches, aimed at identifying and eradicating these self-renewing TICs, have been described. A focus on the metabolic and bioenergetic differences between TICs and less aggressive differentiated cancer cells has thereby emerged as a promising strategy to specifically target the tumorigenic cell compartment. Extrinsic factors, such as nutrient availability or tumor hypoxia, are known to influence the metabolic state of TICs. In this review, we aim to summarize the current knowledge on environmental stress factors and how they affect the metabolism of TICs, with a special focus on microRNA (miRNA)- and hypoxia-induced effects on colon TICs.

Role of miRNAs in Melanoma Metastasis

Tumour metastasis is a multistep process. Melanoma is a highly aggressive cancer and metastasis accounts for the majority of patient deaths. microRNAs (miRNAs) are non-coding RNAs that affect the expression of their target genes. When aberrantly expressed they contribute to the development of melanoma. While miRNAs can act locally in the cell where they are synthesized, they can also influence the phenotype of neighboring melanoma cells or execute their function in the direct tumour microenvironment by modulating ECM (extracellular matrix) and the activity of fibroblasts, endothelial cells, and immune cells. miRNAs are involved in all stages of melanoma metastasis, including intravasation into the lumina of vessels, survival during circulation in cardiovascular or lymphatic systems, extravasation, and formation of the pre-metastatic niche in distant organs. miRNAs contribute to metabolic alterations that provide a selective advantage during melanoma progression. They play an important role in the development of drug resistance, including resistance to targeted therapies and immunotherapies. Distinct profiles of miRNA expression are detected at each step of melanoma development. Since miRNAs can be detected in liquid biopsies, they are considered biomarkers of early disease stages or response to treatment. This review summarizes recent findings regarding the role of miRNAs in melanoma metastasis.

miR-222/GAS5 is involved in DNA damage and cytotoxic effects induced by temozolomide in T98G cell line

Temozolomide (TMZ), a therapeutic DNA alkylator that can cause lethal DNA damage in cancer cells, is widely used for the standard chemotherapy against glioblastoma. However, long-term treatment with TMZ often causes drug resistance and poor prognosis, the mechanism of which remains largely unclear. This study aimed to investigate the possible role of miR-222/GAS5 axis on DNA damage and cytotoxic effects induced by TMZ in glioblastoma cells (T98G). Data suggest that the DNA comet tail length of T98G is positively correlated with the levels of miR-222 (R²  = 0.9808, P < 0.05), and negatively correlated with the levels of GAS5 (R²  = 0.8903, P < 0.05). The optical density value of T98G is negatively correlated with the levels of miR-222 (R²  = 0.7848, P < 0.05), and positively correlated with the levels of GAS5 (R²  = 0.6886, P < 0.05). Furthermore, comet tail length and optical density value are negatively and positively correlated with the levels of O-6-methylguanine-DNA methyltransferase, respectively (R²  = 0.8462, P < 0.05; R²  = 0.7018, P < 0.05). In conclusion, miR-222/GAS5 is involved in DNA damage and cytotoxic effects induced by TMZ, which means that miR-222/GAS5 may have great potential of being used as a biomarker for screening of chemotherapeutic alkylators.

The Emerging Roles of microRNAs in Stem Cell Aging

Aging is the continuous loss of tissue and organ function over time. MicroRNAs (miRNAs) are thought to play a vital role in this process. miRNAs are endogenous small noncoding RNAs that control the expression of target mRNA. They are involved in many biological processes such as developmental timing, differentiation, cell death, stem cell proliferation and differentiation, immune response, aging and cancer. Accumulating studies in recent years suggest that miRNAs play crucial roles in stem cell division and differentiation. In the present chapter, we present a brief overview of these studies and discuss their contributions toward our understanding of the importance of miRNAs in normal and aged stem cell function in various model systems.

Elevated MicroRNA-181a-5p Contributes to Trophoblast Dysfunction and Preeclampsia

OBJECTIVE

It has been demonstrated that preeclampsia is associated with alterations in placental microRNA expression. Previous reports have shown that hsa-miR-181a-5p is overexpressed in human preeclamptic placenta compared with normotensive placenta. The purpose of this study was to explore whether upregulated hsa-miR-181a-5p expression is involved in the ontogenesis of preeclampsia.

METHODS

Twenty preeclamptic placentas and 20 normotensive placentas were obtained from nulliparous women by cesarean section. Expression of hsa-miR-181a-5p in placenta tissues and human trophoblast cell lines was analyzed by reverse transcription polymerase chain reaction. The trophoblast cell lines (HTR-8/SVneo and JAR) were transfected with specific oligonucleotides to upregulate miR-181a-5p expression. The effect of miR-181a-5p expression on proliferation, cell cycle, apoptosis, and invasion in HTR-8/SVneo and JAR cells was then investigated.

RESULT

It was demonstrated that hsa-miR-181a-5p expression was upregulated in preeclamptic placentas and that it may trigger antiproliferation and inhibition of cell cycle progression, induce apoptosis, and suppress invasion in HTR-8/SVneo and JAR cells.

CONCLUSION

Anomalously upregulated hsa-miR-181a-5p expression could contribute to trophoblast dysfunction and may be a crucial factor in the pathogenesis of preeclampsia.

MicroRNA-195: a review of its role in cancers

MicroRNAs (miRNAs) are small and highly conserved noncoding RNAs that regulate gene expression at the posttranscriptional level by binding to the 3′-UTR of target mRNAs. Recently, increasing evidence has highlighted their profound roles in various pathological processes, including human cancers. Deregulated miRNAs function as either oncogenes or tumor suppressor genes in multiple cancer types. Among them, miR-195 has been reported to significantly impact oncogenicity in various neoplasms by binding to critical genes and signaling pathways, enhancing or inhibiting the progression of cancers. In this review, we focus on the expression of miR-195 in regulatory mechanisms and tumor biological processes and discuss the future potential therapeutic implications of diverse types of human malignancies.

Liquid Biopsy Biomarkers in Bladder Cancer: A Current Need for Patient Diagnosis and Monitoring

Bladder Cancer (BC) represents a clinical and social challenge due to its high incidence and recurrence rates, as well as the limited advances in effective disease management. Currently, a combination of cytology and cystoscopy is the routinely used methodology for diagnosis, prognosis and disease surveillance. However, both the poor sensitivity of cytology tests as well as the high invasiveness and big variation in tumour stage and grade interpretation using cystoscopy, emphasizes the urgent need for improvements in BC clinical guidance. Liquid biopsy represents a new non-invasive approach that has been extensively studied over the last decade and holds great promise. Even though its clinical use is still compromised, multiple studies have recently focused on the potential application of biomarkers in liquid biopsies for BC, including circulating tumour cells and DNA, RNAs, proteins and peptides, metabolites and extracellular vesicles. In this review, we summarize the present knowledge on the different types of biomarkers, their potential use in liquid biopsy and clinical applications in BC.

Long non-coding RNA CRYBG3 regulates glycolysis of lung cancer cells by interacting with lactate dehydrogenase A

Cancer cells usually utilize glucose as a carbon source for aerobic glycolysis, a phenomenon known as the Warburg effect. And a high rate of glycolysis has been observed in lung cancer cells. The growing evidence indicates that long non-coding RNAs (lncRNAs) are important players in lung cancer initiation and progression. However, the correlation between lncRNAs and glycolysis remains unclear. In this study, we recognized a lncRNA, LNC CRYBG3, which can interact with lactate dehydrogenase A (LDHA), a vital enzyme of glycolysis, is highly upregulated in both clinical lung cancer tissues and in vitro cultured lung cancer cell lines. A positive correlation between the expression level of LNC CRYBG3 and LDHA expression levels is observed. In another hand, LNC CRYBG3 is a regulator of glycolysis and its overexpression promoted the uptake of glucose and the production of lactate whereas the knockdown of LNC CRYBG3 led to opposite results and suppressed cell proliferation. These results indicated that LNC CRYBG3 might be a novel target for lung cancer treatment.

Emerging roles of microRNAs in the metabolic control of immune cells

Immunometabolism is an emerging field that focuses on the role of cellular metabolism in the regulation of immune cells. Recent studies have revealed an intensive link between the metabolic state and the functions of immune cells. MicroRNAs (miRNAs) are small non-coding, single-stranded RNAs generally consisting of 18-25 nucleotides that exert crucial roles in regulating gene expression at the posttranscriptional level. Although the role of miRNAs in immune regulation has long been recognized, their roles in immunometabolism have not yet been well established. Over the past decade, increasing studies have proven that miRNAs are intensively involved in the metabolic control of immune cells including macrophages, T cells, B cells and dendritic cells. In this review, we highlight recent emerging findings in the miRNA-mediated metabolic control of immune cells.

miR-570 Inhibits Proliferation, Angiogenesis, and Immune Escape of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one common malignancy. The authors previously demonstrated that miR-570 regulates the development of HCC. This study detected the effect of miR-570 on cell apoptosis, angiogenesis, T cell activation, and proliferation in a tumorigenicity assay in nude mice. miR-570 mimics and negative control (NC) were transfected into SMMC7721 cells, and then, the cells were subcutaneously injected in the right flank in nude mice. Six weeks later, the dissected tumors and peripheral blood were collected. Tumor weight and volume were measured, and expression of miR-570 and apoptosis-related gene Bax/Bcl-2 was detected by quantitative real-time polymerase chain reaction. Hematoxylin and eosin, immunohistochemistry of CD31 and vascular endothelial growth factor (VEGF), TUNEL assay, and flow cytometry detection of CD4 and CD8 in peripheral blood were performed. miR-570 mimics suppressed tumor growth compared with the NC, with decreases in tumor weight and tumor volume. Very few CD31 and VEGF were found in tumor sections in miR-570 mimics group. Bax level was significantly increased, while Bcl-2 level was significantly downregulated. Significant lower ratio of CD3⁺CD4⁺ T cells and higher ratio of CD8⁺IFN-γ⁺ T cells were found in peripheral blood and tumor tissues in miR-570 mimics than NC. Collectively, miR-570 plays an important role in the proliferation, angiogenesis, and immune escape of HCC, which might be potential diagnostic and predictive biomarkers.

Circulating exosomal microRNAs in acquired aplastic anemia and myelodysplastic syndromes

Exosomal microRNAs modulate cancer cell metabolism and the immune response. Specific exosomal microRNAs have been reported to be reliable biomarkers of several solid and hematologic malignancies. We examined the possible diagnostic and prognostic values of exosomal microRNAs in two human bone marrow failure diseases: aplastic anemia and myelodysplastic syndromes. After screening 372 microRNAs in a discovery set (n=42) of plasma exosome samples, we constructed a customized PCR plate, including 42 microRNAs, for validation in a larger cohort (n=99). We identified 25 differentially expressed exosomal microRNAs uniquely or frequently present in aplastic anemia and/or myelodysplastic syndromes. These microRNAs could be related to intracellular functions, such as metabolism, cell survival, and proliferation. Clinical parameters and progression-free survival were correlated to microRNA expression levels in aplastic anemia and myelodysplastic syndrome patients before and after six months of immunosuppressive therapy. One microRNA, mir-126-5p, was negatively correlated with a response to therapy in aplastic anemia: patients with higher relative expression of miR-126-5p at diagnosis had the shortest progression-free survival compared to those with lower or normal levels. Our findings suggest utility of exosomal microRNAs in the differential diagnosis of bone marrow failure syndromes. (Registered at clinicaltrials.gov identifiers: 00260689, 00604201, 00378534, 01623167, 00001620, 00001397, 00217594).

Shikonin, vitamin K3 and vitamin K5 inhibit multiple glycolytic enzymes in MCF-7 cells

Glycolysis is the most important source of energy for the production of anabolic building blocks in cancer cells. Therefore, glycolytic enzymes are regarded as potential targets for cancer treatment. Previously, naphthaquinones, including shikonin, vitamin K₃ and vitamin K₅, have been proven to decrease the rate of glycolysis in cancer cells, which is partly due to suppressed pyruvate kinase activity. In the present study, enzymatic assays were performed using MCF-7 cell lysate in order to screen the profile of glycolytic enzymes in cancer cells inhibited by shikonin, vitamin K₃ and vitamin K₅, in addition to pyruvate kinase. Results revealed that hexokinase, phosphofructokinase-1, fructose bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase and pyruvate kinase produced in the process of glycolysis were inhibited by shikonin, vitamin K₃ and vitamin K₅. The results indicated that shikonin, vitamin K₃ and vitamin K₅ are chemical inhibitors of glycolytic enzymes in cancer cells and have potential uses in translational medical applications.

Differential expression profiles of circulating microRNAs in newborns associated to maternal pregestational overweight and obesity

BACKGROUND

The perinatal environment has a role in the establishment of altered metabolic and inflammatory responses, and could be modulated by microRNAs regulating immune and metabolic processes.

OBJECTIVE

To analyze the expression profile of four circulating microRNAs and cytokine serum concentrations in neonates born to overweight and obese women.

METHODS

Pregnant women were included and grouped by pregestational body mass index (21 with normal weight, 10 overweight and 10 obese women). A peripheral blood sample was obtained from newborn infants and used to determine circulating miRNAs expression and cytokine serum concentrations.

RESULTS

There were significant differences in the expression of three microRNAs between newborns of pregestational obese women and newborns from pregestational normal weight women: miR-155 (p = 0.03), miR-181a (p = 0.02) and miR-221 (p = 0.04). A significant reduction in IL-1β (p = 0.005) expression was also found in newborns of overweight women; although this cytokine was also diminished in newborns of obese women, this was not statistically significant. An association between IL-1β concentrations and miR-146a and miR-221 expression was also observed.

CONCLUSIONS

Expression of miR-155, miR-181a and miR-221 differs in infants born to obese women compared with infants born to normal weight women. Changes in microRNA expression could participate in the epigenetic foetal programming of metabolic disorders in children born to obese women.

Therapeutic strategy with artificially-designed i-lncRNA targeting multiple oncogenic microRNAs exhibits effective antitumor activity in diffuse large B-cell lymphoma

In diffuse large B-cell lymphoma (DLBCL), many oncogenic microRNAs (OncomiRs) are highly expressed to promote disease development and progression by inhibiting the expression and function of certain tumor suppressor genes, and these OncomiRs comprise a promising new class of molecular targets for the treatment of DLBCL. However, most current therapeutic studies have focused on a single miRNA, with limited treatment outcomes. In this study, we generated tandem sequences of 10 copies of the complementary binding sequences to 13 OncomiRs and synthesized an interfering long non-coding RNA (i-lncRNA). The highly-expressed i-lncRNA in DLBCL cells would compete with the corresponding mRNAs of OncomiR target genes for binding OncomiRs, thereby effectively consuming a large amount of OncomiRs and protecting many tumor suppressor genes. The in vitro experiments confirmed that the i-lncRNA expression significantly inhibited cell proliferation, induced cell cycle arrest and apoptosis in DLBCL cell lines, mainly through upregulating the expression of PTEN, p27kip1, TIMP3, RECK and downregulating the expression of p38/MAPK, survivin, CDK4, c-myc. In the established SUDHL-4 xenografts in nude mice, the treatment strategy involving adenovirus-mediated i-lncRNA expression significantly inhibited the growth of DLBCL xenografts. Therefore, this treatment would specifically target the carcinogenic effects of many OncomiRs that are usually expressed in DLBCL and not in normal cells, such a strategy could improve anti-tumor efficacy and safety and may be a good prospect for clinical applications.

The biological roles and clinical implications of microRNAs in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) accounts for about 3% of tumors in adults as well as 85% of all primary renal carcinoma. And it is the third most predominant urological carcinoma, but it has the maximum mortality rate. Early diagnosis and proper follow-up of ccRCC patients may improve the prognosis of the illness. Thus, it is imperative to understand the new biomarkers of ccRCC and study new method for the modern therapy of this deadly disease. Furthermore, a large number of microRNAs (miRNAs), small non-coding RNAs, have been relevant to tumor type, stage, or survival and miRNAs might be progressed as the markers of diagnosis or prognosis in ccRCC. A growing body of data also advised the rationality of regarding miRNAs as therapeutic targets for ccRCC treatment. In this review, we tried to summarize biogenesis of miRNAs and their expression profiles, biological roles, and clinical implications in ccRCC.