Emergence of MicroRNAs as Key Players in Cancer Cell Metabolism

A Multi-Omics Approach Reveals Enrichment in Metabolites Involved in the Regulation of the Glutathione Pathway in LIN28B-Dependent Cancer Cells

The RNA-binding protein LIN28B, identified as an independent risk factor in high-risk neuroblastoma patients, is implicated in adverse treatment outcomes linked to metastasis and chemoresistance. Despite its clinical significance, the impact of LIN28B on neuroblastoma cell metabolism remains unexplored. This study employs a multi-omics approach, integrating transcriptome and metabolome data, to elucidate the global metabolic program associated with varying LIN28B expression levels over time. Our findings reveal that escalating LIN28B expression induces a significant metabolic rewiring in neuroblastoma cells. Specifically, LIN28B prompts a time-dependent increase in the release rate of metabolites related to the glutathione and aminoacyl-tRNA biosynthetic pathways, concomitant with a reduction in glucose uptake. These results underscore the pivotal role of LIN28B in governing neuroblastoma cell metabolism and suggest a potential disruption in the redox balance of LIN28B-bearing cells. This study offers valuable insights into the molecular mechanisms underlying LIN28B-associated adverse outcomes in neuroblastoma, paving the way for targeted therapeutic interventions.

IRF2BP2 drives lymphatic metastasis in OSCC cells by elevating mitochondrial fission-dependent fatty acid oxidation

Lymph node metastasis (LNM) is a major determinant for the poor outcome of oral squamous cell carcinoma (OSCC). Interferon regulatory factor 2 binding protein 2 (IRF2BP2) has been reported to modulate the development and progression of several types of cancers, while its role in OSCC with LNM has not been reported yet. The expression of IRF2BP2 and its association with LNM were evaluated by immunohistochemistry and qualitative reverse transcription polymerase chain reaction in clinically collected OSCC tissues. Then, loss-of-function and rescue assays were conducted to identify the role of IRF2BP2-mediated fatty acid oxidation (FAO) in the invasion, lymphoinvasion, and epithelial-mesenchymal transition (EMT) in OSCC cells. Importantly, confocal microscope, transmission electron microscope, immunofluorescence, and Western blot were applied to identify the involvement of mitochondrial fission in IRF2BP2-regulated FAO. Lastly, the in vivo models were established to evaluate the role of IRF2BP2 in OSCC. IRF2BP2 overexpression has been associated with LNM in OSCC, whose knockdown inhibited invasion, lymphoinvasion, and EMT of OSCC cells, as well as retarded FAO rate with CPT1A downregulation. And CPT1A overexpression rescued invasion, lymphoinvasion, and induced EMT in IRF2BP2-silenced OSCC cells. Mechanically, IRF2BP2 accelerated mitochondrial fission by contributing to Drp1 S616 phosphorylation and mitochondrial localization, resulting in the upregulation of CPT1A. In addition, IRF2BP2 knockdown significantly inhibited tumor growth and LNM in vivo. The highly expressed IRF2BP2 may induce the phosphorylation and mitochondrial translocation of Drp1 to activate mitochondrial fission, which upregulated CPT1A expression and FAO rate, resulting in LNM in OSCC. This highlighted a potential therapeutic vulnerability for the treatment of LNM+ OSCC via targeting IRF2BP2-FAO.

miRNA-Based Technologies in Cancer Therapy

The discovery of therapeutic miRNAs is one of the most exciting challenges for pharmaceutical companies. Since the first miRNA was discovered in 1993, our knowledge of miRNA biology has grown considerably. Many studies have demonstrated that miRNA expression is dysregulated in many diseases, making them appealing tools for novel therapeutic approaches. This review aims to discuss miRNA biogenesis and function, as well as highlight strategies for delivering miRNA agents, presenting viral, non-viral, and exosomic delivery as therapeutic approaches for different cancer types. We also consider the therapeutic role of microRNA-mediated drug repurposing in cancer therapy.

miR-128-3p inhibits intramuscular adipocytes differentiation in chickens by downregulating FDPS

BACKGROUND

Intramuscular fat (IMF) content is the major indicator for evaluating chicken meat quality due to its positive correlation with tenderness, juiciness, and flavor. An increasing number of studies are focusing on the functions of microRNAs (miRNAs) in intramuscular adipocyte differentiation. However, little is known about the association of miR-128-3p with intramuscular adipocyte differentiation. Our previous RNA-seq results indicated that miR-128-3p was differentially expressed at different periods in chicken intramuscular adipocytes, revealing a possible association with intramuscular adipogenesis. The purpose of this research was to investigate the biological functions and regulatory mechanism of miR-128-3p in chicken intramuscular adipogenesis.

RESULTS

The results of a series of assays confirmed that miR-128-3p could promote the proliferation and inhibit the differentiation of intramuscular adipocytes. A total of 223 and 1,050 differentially expressed genes (DEGs) were identified in the mimic treatment group and inhibitor treatment group, respectively, compared with the control group. Functional enrichment analysis revealed that the DEGs were involved in lipid metabolism-related pathways, such as the MAPK and TGF-β signaling pathways. Furthermore, target gene prediction analysis showed that miR-128-3p can target many of the DEGs, such as FDPS, GGT5, TMEM37, and ASL2. The luciferase assay results showed that miR-128-3p targeted the 3' UTR of FDPS. The results of subsequent functional assays demonstrated that miR-128-3p acted as an inhibitor of intramuscular adipocyte differentiation by targeting FDPS.

CONCLUSION

miR-128-3p inhibits chicken intramuscular adipocyte differentiation by downregulating FDPS. Our findings provide a theoretical basis for the study of lipid metabolism and reveal a potential target for molecular breeding to improve meat quality.

Post-Transcriptional and Epigenetic Regulation of Estrogen Signaling

Post-translational and epigenetic regulation are important mechanisms controlling functions of genes and proteins. Although the "classic" estrogen receptors (ERs) have been acknowledged to function in mediating estrogen effects via transcriptional mechanisms, estrogenic agents modulate the turnover of several proteins via post-transcriptional and post-translational pathways including epigenetics. For instance, the metabolic and angiogenic action of G-protein coupled estrogen receptor (GPER) in vascular endothelial cells has been recently elucidated. By interacting with GPER, 17β-estradiol and the GPER agonist G1 enhance endothelial stability of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) and capillary tube formation by increasing ubiquitin-specific peptidase 19 levels, thereby reducing PFKFB3 ubiquitination and proteasomal degradation. In addition to ligands, the functional expression and trafficking of ERs can be modulated by post-translational modification, including palmitoylation. MicroRNAs (miRNAs), the most abundant form of endogenous small RNAs in humans, regulate multiple target genes and are at the center of the multi-target regulatory network. This review also discusses the emerging evidence of how miRNAs affect glycolytic metabolism in cancer, as well as their regulation by estrogens. Restoring dysregulated miRNA expression represents a promising strategy to counteract the progression of cancer and other disease conditions. Accordingly, estrogen post-transcriptional regulatory and epigenetic mechanisms represent novel targets for pharmacological and nonpharmacological intervention for the treatment and prevention of hormone-sensitive noncommunicable diseases, including estrogen-sensitive cancers of the reproductive system in women. SIGNIFICANCE STATEMENT: The effects of estrogen are mediated by several mechanisms that are not limited to the transcriptional regulation of target genes. Slowing down the turnover of master regulators of metabolism by estrogens allows cells to rapidly adapt to environmental cues. Identification of estrogen-targeted microRNAs may lead to the development of novel RNA therapeutics that disrupt pathological angiogenesis in estrogen-dependent cancers.

Small RNA-seq and hormones in the testes of dwarf hamsters (Cricetulus barabensis) reveal the potential pathways in photoperiod regulated reproduction

Photoperiod regulates the functions and development of gonadal organs of seasonally breeding animals, resulting in breeding peaks in specific seasons. miRNA plays an important role in the regulation of testicular physiological functions. However, the relationship between photoperiods and miRNA levels in testes has yet to be conclusively determined. We investigated testicular miRNA of striped dwarf hamster (Cricetulus barabensis) responses to different photoperiods (long daylength [LD], moderate daylength [MD], and short daylength [SD]) and the potential pathways involved in photoperiod regulated reproduction. Testicular weights and reproductive hormone levels were measured in each of photoperiod treatments after 30 days. The concentrations of testosterone (T) and dihydrogen testosterone (DHT) in testes and Gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) in serum were higher in MD than in the other two groups. Testicular weights were heaviest in MD. Small RNA-seq was performed for the testes of hamsters in three groups. A total of 769 miRNAs were identified, of which 83 were differentially expressed between LD, MD, and SD. GO and KEGG analysis of target genes revealed that some miRNAs influence testicular activities by regulating the pathways related to cell apoptosis and metabolism. Gene expression pattern analysis showed that the MAPK signaling pathway may be the core pathway for photoperiodic regulation of reproduction. These results suggest that moderate daylength is more suitable for hamster reproduction while long daylength and short daylength may regulate reproduction through different molecular pathways.

miR-141-3p Promotes the Cisplatin Sensitivity of Osteosarcoma Cell through Targeting the Glutaminase [GLS]-Mediated Glutamine Metabolism

AIMS

This study aimed to evaluate the roles and molecular targets of miRNA-141-3p in the cisplatin sensitivity of osteosarcoma.

BACKGROUND

Osteosarcoma is one of the most common-type bone tumors, occurring mainly in children and adolescents. Cancer cells display dysregulated cellular metabolism, such as the abnormally elevated glutamine metabolism.

OBJECTIVE

Non-coding RNA miRNA-141-3p has been reported to act as a tumor suppressor in osteosarcoma. Currently, the precise molecular mechanisms for the miR- 141-3p-mediated chemosensitivity through regulating glutamine metabolism remain unclear.

METHODS

We collected thirty paired OS tumors and their adjacent normal tissues. The osteosarcoma cell lines [Saos-2] and normal osteoblast cells, hFOB1.19, were used for in vitro experiments. RT-qPCR and Western blot were applied for gene expression detections. Targets of miR-141-3p were predicted from starBase. The MTT and flow cytometric assays were performed to determine cell growth and apoptosis rates. The cellular glutamine metabolism was monitored by glutamine uptake assay and the glutaminase [GLS] activity assay.

RESULTS

We reported that miR-141-3p were significantly downregulated in osteosarcoma tissues and cells. Overexpression of miR-141-3p suppressed OS cell growth and sensitized OS cells to cisplatin. In addition, glutamine metabolism was significantly increased in osteosarcoma. We characterized that GLS played oncogenic roles in osteosarcoma and validated GLS was a direct target of miR-141-3p in OS cells. Rescue experiments consistently demonstrated that miR-141-3p-promoted cisplatin sensitivity was achieved by targeting GLS directly.

CONCLUSION

Overall, our findings revealed new molecular mechanisms of the miR-141- 3p-modulated cisplatin sensitization through targeting the GLS-glutamine metabolism pathway. This study will contribute to developing new therapeutic approaches for the treatments of chemoresistant osteosarcoma.

Antileukemic Activity of hsa-miR-203a-5p by Limiting Glutathione Metabolism in Imatinib-Resistant K562 Cells

Imatinib has been the first and most successful tyrosine kinase inhibitor (TKI) for chronic myeloid leukemia (CML), but many patients develop resistance to it after a satisfactory response. Glutathione (GSH) metabolism is thought to be one of the factors causing the emergence of imatinib resistance. Since hsa-miR-203a-5p was found to downregulate Bcr-Abl1 oncogene and also a link between this oncogene and GSH metabolism is reported, the present study aimed to investigate whether hsa-miR-203a-5p could overcome imatinib resistance by targeting GSH metabolism in imatinib-resistant CML cells. After the development of imatinib-resistant K562 (IR-K562) cells by gradually exposing K562 (C) cells to increasing doses of imatinib, resistant cells were transfected with hsa-miR-203a-5p (R+203). Thereafter, cell lysates from various K562 cell sets (imatinib-sensitive, imatinib-resistant, and miR-transfected imatinib-resistant K562 cells) were used for GC-MS-based metabolic profiling. L-alanine, 5-oxoproline (also known as pyroglutamic acid), L-glutamic acid, glycine, and phosphoric acid (Pi)-five metabolites from our data, matched with the enumerated 28 metabolites of the MetaboAnalyst 5.0 for the GSH metabolism. All of these metabolites were present in higher concentrations in IR-K562 cells, but intriguingly, they were all reduced in R+203 and equated to imatinib-sensitive K562 cells (C). Concludingly, the identified metabolites associated with GSH metabolism could be used as diagnostic markers.

FBP1 /miR-24-1/enhancer axis activation blocks renal cell carcinoma progression via Warburg effect

Warburg effect is a pivotal hallmark of cancers and appears prevalently in renal cell carcinoma (RCC). FBP1 plays a negative role in Warburg effect as a rate-limiting enzyme in gluconeogenesis, yet its mechanism in RCC remains to be further characterized. Herein, we revealed that FBP1 was downregulated in RCC tissue samples and was related to the poor survival rate of RCC. Strikingly, miR-24-1 whose DNA locus is overlapped with enhancer region chr9:95084940-95087024 was closely linked with the depletion of FBP1 in RCC. Of note, miRNAs like miR-24-1 whose DNA loci are enriched with H3K27ac and H3K4me1 modifications are belonging to nuclear activating miRNAs (NamiRNAs), which surprisingly upregulate target genes in RCC through enhancer beyond the conventional role of repressing target gene expression. Moreover, miR-24-1 reactivated the expression of FBP1 to suppress Warburg effect in RCC cells, and subsequently inhibited proliferation and metastasis of RCC cells. In mechanism, the activating role of miR-24-1 was dependent on enhancer integrity by dual luciferase reporter assay and CRISPR/Cas9 system. Ultimately, animal assay in vivo validated the suppressive function of FBP1 on 786-O and ACHN cells. Collectively, the current study highlighted that activation of FBP1 by enhancer-overlapped miR-24-1 is capable of contributing to Warburg effect repression through which RCC progression is robustly blocked, providing an alternative mechanism for RCC development and as well implying a potential clue for RCC treatment strategy.

Perspectives of using microRNA-loaded nanocarriers for epigenetic reprogramming of drug resistant colorectal cancers

Epigenetic regulation by microRNAs (miRs) demonstrated a promising therapeutic potential of these molecules to regulate genetic activity in different cancers, including colorectal cancers (CRCs). The RNA-based therapy does not change genetic codes in tumor cells but can silence oncogenes and/or reactivate inhibited tumor suppressor genes. In many cancers, specific miRs were shown to promote or stop tumor progression. Among confirmed and powerful epigenetic regulators of colon carcinogenesis and development of resistance are onco-miRs, which include let-7, miR-21, miR-22, miR-23a, miR-27a, miR-34, miR-92, miR-96, miR-125b, miR-135b, miR-182, miR-200c, miR-203, miR-221, miR-421, miR-451, and others. Moreover, various tumor-suppressor miRs (miR-15b-5b, miR-18a, miR-20b, miR-22, miR-96, miR-139-5p, miR-145, miR-149, miR-197, miR-199b, miR-203, miR-214, miR-218, miR-320, miR-375-3p, miR-409-3p, miR-450b-5p, miR-494, miR-577, miR-874, and others) were found silenced in drug-resistant CRCs. Re-expression of tumor suppressor miR is complicated by the chemical nature of miRs that are not long-lasting compounds and require protection from the enzymatic degradation. Several recent studies explored application of miRs using nanocarrier complexes. This study critically describes the most successfully tested nanoparticle complexes used for intracellular delivery of nuclear acids and miRs, including micelles, liposomes, inorganic and polymeric NPs, dendrimers, and aptamers. Nanocarriers shield incorporated miRs and improve the agent stability in circulation. Attachment of antibodies and/or specific peptide or ligands facilitates cell-targeted miR delivery. Addressing in vivo challenges, a broad spectrum of non-toxic materials has been tested and indicated reliable advantages of lipid-based (lipoplexes) and polymer-based liposomes. Recent cutting-edge developments indicated that lipid-based complexes with multiple cargo, including several miRs, are the most effective approach to eradicate drug-resistant tumors. Focusing on CRC-specific miRs, this review provides a guidance and insights towards the most promising direction to achieve dramatic reduction in tumor growth and metastasis using miR-nanocarrier complexes.

Correlation between stage of prostate cancer and tyrosine and tryptophan in urine samples measured electrochemically

Prostate cancer (PCa) is the second most common cancer in men and one of the leading causes of cancer-related deaths. Early detection is the key to successful treatment and provides the greatest chance to cure the patient. Currently, early detection involves screening for prostate-specific antigen levels in blood, which is not a tumor-specific biomarker. There is a critical need to develop clinically useful methods for screening for more reliable biomarkers. Here, we introduce an electrochemical biosensor that measures the concentrations of the amino acids tyrosine and tryptophan, and propose it as a possible diagnostic and prognostic tool for PCa. The limits of detection of tyrosine and tryptophan using the electrochemical sensors were 1.15 and 1.13 μmol/L in 1:10 urine: PBS, respectively. This study is the first to present electrochemical measurements of tyrosine and tryptophan directly in patient urine samples. We demonstrated an inverse correlation between the measured electrochemical signals and the severity of PCa. The most notable observation was a significant difference between controls and metastatic PCa patients (P ≤ 0.001). This observation was further validated using Liquid-Chromatography-Mass Spectrometry. Our data provides the basis for further research with electrochemical measurements of tyrosine and tryptophan as potential biomarkers for PCa.

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.

Bioenergetic and Metabolic Adaptation in Tumor Progression and Metastasis

The ability of cancer cells to adjust their metabolism in response to environmental changes is a well-recognized hallmark of cancer. Diverse cancer and non-cancer cells within tumors compete for metabolic resources. Metabolic demands change frequently during tumor initiation, progression and metastasis, challenging our quest to better understand tumor biology and develop novel therapeutics. Vascularization, physical constraints, immune responses and genetic instability promote tumor evolution resulting in immune evasion, opportunities to breach basement membrane barriers and spread through the circulation and lymphatics. In addition, the unfolded protein response linked to the ubiquitin proteasome system is a key player in addressing stoichiometric imbalances between nuclear and mitochondrially-encoded protein subunits of respiratory complexes, and nuclear-encoded mitochondrial ribosomal protein subunits. While progressive genetic changes, some of which affect metabolic adaptability, contribute to tumorigenesis and metastasis through clonal expansion, epigenetic changes are also important and more dynamic in nature. Understanding the role of stromal and immune cells in the tumor microenvironment in remodeling cancer cell energy metabolism has become an increasingly important area of research. In this perspective, we discuss the adaptations made by cancer cells to balance mitochondrial and glycolytic energy metabolism. We discuss how hypoxia and nutrient limitations affect reductive and oxidative stress through changes in mitochondrial electron transport activity. We propose that integrated responses to cellular stress in cancer cells are central to metabolic flexibility in general and bioenergetic adaptability in particular and are paramount in tumor progression and metastasis.

Targeting of PFKFB3 with miR-206 but not mir-26b inhibits ovarian cancer cell proliferation and migration involving FAK downregulation

Few studies explored the role of microRNAs (miRNAs) in the post-transcriptional regulation of glycolytic proteins and downstream effectors in ovarian cancer cells. We recently showed that the functional activation of the cytoskeletal regulator FAK in endothelial cells is fostered by the glycolytic enhancer 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3). We tested the hypothesis that miR-206 and mir-26b, emerging onco-suppressors targeting PFKFB3 in estrogen-dependent tumors, would regulate proliferation and migration of serous epithelial ovarian cancer (EOC) cells via common glycolytic proteins, i.e., GLUT1 and PFKFB3, and downstream FAK. PFKFB3 was overexpressed in SKOV3, and its pharmacological inhibition with 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO) significantly reduced cell proliferation and motility. Both miR-206 and miR-26b directly targeted PFKFB3 as evaluated by a luciferase reporter assay. However, endogenous levels of miR-26b were higher than those of miR-206, which was barely detectable in SKOV3 as well as OVCAR5 and CAOV3 cells. Accordingly, only the anti-miR-26b inhibitor concentration-dependently increased PFKFB3 levels. While miR-206 overexpression impaired proliferation and migration by downregulating PFKFB3 levels, the decreased PFKFB3 protein levels related to miR-26 overexpression had no functional consequences in all EOC cell lines. Finally, consistent with the migration outcome, exogenous miR-206 and miR-26b induced opposite effects on the levels of total FAK and of its phosphorylated form at Tyr576/577. 3PO did not prevent miR-26b-induced SKOV3 migration. Overall, these results support the inverse relation between endogenous miRNA levels and their tumor-suppressive effects and suggest that restoring miR-206 expression represents a potential dual anti-PFKFB3/FAK strategy to control ovarian cancer progression.

Therapeutic Metabolic Reprograming Using microRNAs: From Cancer to HIV Infection

MicroRNAs (miRNAs) are crucial regulators of cellular processes, including metabolism. Attempts to use miRNAs as therapeutic agents are being explored in several areas, including the control of cancer progression. Recent evidence suggests fine tuning miRNA activity to reprogram tumor cell metabolism has enormous potential as an alternative treatment option. Indeed, cancer growth is known to be linked to profound metabolic changes. Likewise, the emerging field of immunometabolism is leading to a refined understanding of how immune cell proliferation and function is governed by glucose homeostasis. Different immune cell types are now known to have unique metabolic signatures that switch in response to a changing environment. T-cell subsets exhibit distinct metabolic profiles which underlie their alternative differentiation and phenotypic functions. Recent evidence shows that the susceptibility of CD4⁺ T-cells to HIV infection is intimately linked to their metabolic activity, with many of the metabolic features of HIV-1-infected cells resembling those found in tumor cells. In this review, we discuss the use of miRNA modulation to achieve metabolic reprogramming for cancer therapy and explore the idea that the same approach may serve as an effective mechanism to restrict HIV replication and eliminate infected cells.

Analysis of serum microRNA in exosomal vehicles of papillary thyroid cancer

PURPOSE

In this study, we investigated the profile of microRNAs (miRNAs) contained in exosomes secreted in the serum of patients with papillary thyroid cancer (PTC).

METHODS

Exosome were isolated by adding ExoQuick Exosome Precipitation Solution. Dynamic light scattering (DLS) and western blotting analysis were used to ensure the quality of exosomes. The expression levels of miRNAs were investigated using custom-designed TaqMan Advanced miRNA Array Cards in the screening cohort and using specific TaqMan Advanced MicroRNA Assays in the validation cohort.

RESULTS

We identified miR24-3p, miR146a-5p, miR181a-5p and miR382-5p with different expression levels in two different series of 56 and 58 PTC patients as compared with healthy controls. Significant differences in the expression of three PTC exosomal miRNAs, depending on the presence of lymph node metastasis, were detected in only one PTC series. When comparing the expression levels of some PTC-specific exosomal miRNAs with those of the same miRNAs circulating free of any encapsulation, we found a significant correlation for only miR24-3p, suggesting that only select miRNAs are secreted in exosomes.

CONCLUSIONS

Our findings demonstrate that four miRNAs are differently secreted in the exosomes of PTC patients, whereas no conclusive results were found to characterize PTCs with lymph node metastasis, suggesting caution in the use of circulating exosomal miRNA expression levels as lymph node metastasis biomarkers. Further investigation into the mechanisms governing miRNA secretion in tumor cells are required.

MicroRNAs and Metabolism: Revisiting the Warburg Effect with Emphasis on Epigenetic Background and Clinical Applications

Since the well-known hallmarks of cancer were described by Hanahan and Weinberg, fundamental advances of molecular genomic technologies resulted in the discovery of novel puzzle pieces in the multistep pathogenesis of cancer. MicroRNAs are involved in the altered epigenetic pattern and metabolic phenotype of malignantly transformed cells. They contribute to the initiation, progression and metastasis-formation of cancers, also interacting with oncogenes, tumor-suppressor genes and epigenetic modifiers. Metabolic reprogramming of cancer cells results from the dysregulation of a complex network, in which microRNAs are located at central hubs. MicroRNAs regulate the expression of several metabolic enzymes, including tumor-specific isoforms. Therefore, they have a direct impact on the levels of metabolites, also influencing epigenetic pattern due to the metabolite cofactors of chromatin modifiers. Targets of microRNAs include numerous epigenetic enzymes, such as sirtuins, which are key regulators of cellular metabolic homeostasis. A better understanding of reversible epigenetic and metabolic alterations opened up new horizons in the personalized treatment of cancer. MicroRNA expression levels can be utilized in differential diagnosis, prognosis stratification and prediction of chemoresistance. The therapeutic modulation of microRNA levels is an area of particular interest that provides a promising tool for restoring altered metabolism of cancer cells.

Hypoxia boosts aerobic glycolysis of carcinoma：a complex process for tumor development

Hypoxia, a common feature in malignant tumors, is mainly caused by insufficient oxygen supply. Hypoxia is closely related to cancer development, affecting cancer invasion and metastasis, energy metabolism and other pathological processes, and is not conducive to cancer treatment and prognosis. Tumor cells exacerbate metabolic abnormalities to adapt to the hypoxic microenvironment, especially to enhance aerobic glycolysis. Glycolysis leads to an acidic microenvironment in cancer tissues, enhancing cancer metastasis, deterioration and drug resistance. Therefore, hypoxia is a therapeutic target that cannot be ignored in cancer treatment. The adaptation of tumor cells to hypoxia is mainly regulated by hypoxia inducible factors (HIFs), and the stability of HIFs is improved under hypoxic conditions. HIFs can promote the glycolysis of tumors by regulating glycolytic enzymes, transporters, and participates in regulating the TCA (tricarboxylic acid) cycle. In addition, HIFs indirectly affect glycolysis through its interaction with non-coding RNAs. Therefore, targeting hypoxia and HIFs are important tumor therapies.

Potential Alternatives to Conventional Cancer Therapeutic Approaches: The Way Forward

onventional cancer therapeutic approaches broadly include chemotherapy, radiation therapy and surgery. These established approaches have evolved over several decades of clinical experience. For a complex disease like cancer, satisfactory treatment remains an enigma for the simple fact that the causal factors for cancer are extremely diverse. In order to overcome existing therapeutic limitations, consistent scientific endeavors have evolved several potential therapeutic approaches, majority of which focuses essentially on targeted drug delivery, minimal concomitant ramification, and selective high cytotoxicity. The current review focuses on highlighting some of these potential alternatives that are currently in various stages of in vitro, in vivo, and clinical trials. These include physical, chemical and biological entities that are avidly being explored for therapeutic alternatives. Some of these entities include suicide gene, micro RNA, modulatory peptides, ultrasonic waves, free radicals, nanoparticles, phytochemicals, and gene knockout, and stem cells. Each of these techniques may be exploited exclusively and in combination with conventional therapeutic approaches thereby enhancing the therapeutic efficacy of the treatment. The review intends to briefly discuss the mechanism of action, pros, and cons of potential alternatives to conventional therapeutic approaches.

Allele-Specific MicroRNA-Mediated Regulation of a Glycolysis Gatekeeper PDK1 in Cancer Metabolism

BACKGROUND

Emerging evidence has revealed that genetic variations in microRNA (miRNA) binding sites called miRSNPs can alter miRNA binding in an allele-specific manner and impart prostate cancer (PCa) risk. Two miRSNPs, rs1530865 (G > C) and rs2357637 (C > A), in the 3' untranslated region of pyruvate dehydrogenase kinase 1 (PDK1) have been previously reported to be associated with PCa risk. However, these results have not been functionally validated.

METHODS

In silico analysis was used to predict miRNA-PDK1 interactions and was tested using PDK1 knockdown, miRNA overexpression and reporter gene assay.

RESULTS

PDK1 expression was found to be upregulated in PCa metastasis. Further, our results show that PDK1 suppression reduced the migration, invasion, and glycolysis of PCa cells. Computational predictions showed that miR-3916, miR-3125 and miR-3928 had a higher binding affinity for the C allele than the G allele for the rs1530865 miRSNP which was validated by reporter gene assays. Similarly, miR-2116 and miR-889 had a higher affinity for the A than C allele of the rs2357637 miRSNP. Overexpression of miR-3916 and miR-3125 decreased PDK1 protein levels in cells expressing the rs1530865 SNP C allele, and miR-2116 reduced in cells with the rs2357637 SNP A allele.

CONCLUSIONS

The present study is the first to report the regulation of the PDK1 gene by miRNAs in an allele-dependent manner and highlights the role of PDK1 in metabolic adaption associated with PCa progression.

The expression of miR-513c and miR-3163 was downregulated in tumor tissues compared with normal adjacent tissue of patients with breast cancer

Background

Breast cancer (BC) is the most invasive cancer with different subtypes that its metabolism is unique compared with normal cells. Glutamine is considered critical nutrition that many cancer cells, particularly BC cells, are dependent on it for growth and proliferation. Therefore, targeting glutamine metabolism, especially enzymes that are related to this pathway, can be beneficial to design anti-cancer agents. Recent evidence has shown that microRNAs (miRNAs), with a short length and single-strand properties, play a prominent role in regulating the genes related to glutamine metabolism, which may control the development of cancer.

Methods

In silico analysis confirmed that miR-513c and miR-3163 might be involved in glutamine metabolism. The expression level of these two miRNAs was evaluated in eighty BC tissues and normal adjacent tissues. Furthermore, GSE38167, GSE38867, GSE42128, GSE45666, and GSE53179 were employed from gene expression omnibus (GEO). The Limma package was utilized to identify differentially expressed miRNAs (DEMs) of mentioned datasets to evaluate miR-513c and miR-3163 expression. Further, in silico analysis was utilized to predict the potential biological processes and molecular pathways of miR-513c and miR-3163, based on their target genes.

Results

In silico studies revealed top categories of biological processes and cellular pathways that might play a critical role in metabolism reprogramming and cancer development and were target genes for miR-513c and miR-3163. The current study showed that miR-513c (p value = 0.02062 and FC =  − 2.3801) and miR-3163 (p value = 0.02034 and FC =  − 2.3792) were downregulated in tumor tissues compared to normal adjacent tissues. The analysis of GEO microarray datasets showed that miR-513c was downregulated in GSE38167, GSE38867, GSE42128, GSE45666 and GSE53179, whereas there was a significant downregulation of miR-3163 in only two studies, including GSE38867 and GSE42128 that they were in accordance with our experimental results. Furthermore, the subgroup analysis did not show any substantial relationship between expression levels of these two miRNAs and factors such as age, family history of cancer, and abortion history.

Conclusion

MiR-513c and miR-3163 were downregulated in BC tissues, which might serve as tumor suppressors. They are suggested as potential therapeutic targets for patients with BC.

Application and Evaluation of [99mTc]-Labeled Peptide Nucleic Acid Targeting MicroRNA-155 in Breast Cancer Imaging

It has been reported that dysregulation of microRNA-155 expression and function is associated with tumorigenesis, growth, tumor subtypes, invasion, and poor survival rates. Peptide nucleic acid (PNA), an artificially synthesized nucleic acid mimic, has been applied for molecular diagnosis. In this study, a PNA sequence that undergoes complementary binding to miR-155 was labeled with ^99mTc to evaluate whether the tracer could visualize the expression of miR-155 in breast cancer. Both antisense PNA (anti-PNA, fully complementary bound to human mature miR-155, referred to as “anti-PNA-155”) and mismatched PNA (referred to as “mis-PNA”) single strands containing 23-mer were synthesized. The relative expression of miR-155 in MCF-7 cells and tumors was higher than that in MDA-MB-231 cells and tumors. Single-photon emission computed tomography (SPECT) scan showed that radioactivity mainly accumulated in kidney. MCF-7 tumors, but not MDA-MB-231 tumors, were clearly visualized after [^99mTc]anti-PNA-155 injection. MCF-7 tumors were less visible when coinjected with 100-fold excess of anti-PNA-155 or injected with [^99mTc]mis-PNA, which suggested specific binding. Biodistribution study results were consistent with SPECT imaging. We successfully demonstrated that [^99mTc]anti-PNA-155 could visualize miR-155 expression in vivo, suggesting it may be a promising probe applied in breast cancer.

Role of the miR-133a-5p/FBXO6 axis in the regulation of intervertebral disc degeneration

OBJECTIVE

Low back pain is a leading cause of disabilities worldwide, and intervertebral disc degeneration (IVDD)-related disorders have been recognised as one of the main contributors. Nevertheless, the underlying mechanism has not yet been fully understood. The aim of this study was to investigate the role of the miR-133a-5p/FBXO6 axis in the regulation of IVDD.

METHODS

RT-qPCR, WB and IHC were performed to assess the expression of FBXO6 in human IVD tissues. Nucleus pulposus (NP) cells were treated with IL-1β to induce IVDD cellular model. Silence of FBXO6 was achieved using specific siRNAs. CCK-8 assay, flow cytometry, TUNEL assay, RT-qPCR and WB were used to evaluate the role and mechanism of FBXO6 in the process of IVDD. Online tools, GSE datasets and RT-qPCR were used to search the candidate miRNAs targeting FBXO6. The direct binding sites between FBXO6 and miR-133a-5p were further verified by a dual luciferase assay. RT-qPCR, WB and rescue experiments were conducted to identify the regulatory function of miR-133a-5p on the expression of aggrecan, collagen Ⅱ, MMP3, ADAMTS5, IL-6 and COX2. In addition, the role of the NF-κB pathway in regulating miR-133a-5p was studied using lentiviral shRNA, WB and RT-qPCR.

RESULTS

Results showed that FBXO6 mainly expressed in the NP tissue of IVD and the expression of FBXO6 decreased with the process of IVDD as well as under IL-1β stimulation. The silence of FBXO6 led to the decreased expression of aggrecan and collagen Ⅱ and the increased expression of MMP3, ADAMTS5, IL-6 and COX2, which further induced the degeneration of NP cells. The bioinformatic analysis showed that miR-133a-5p was the candidate miRNA targeting FBXO6. miR-133a-5p was upregulated in IVDD tissues and significantly inhibited the expression of FBXO6. The inhibition of miR-133a-5p ameliorated the acceleration of IVDD induced by the silence of FBXO6 in vitro. Moreover, it was demonstrated that IL-1β regulated the expression of the miR-133a-5p/FBXO6 axis via the NF-κB pathway in NP cells.

CONCLUSION

miR-133a-5p was upregulated by IL-1β to aggravate intervertebral disc degeneration via sponging FBXO6. Inhibiting miR-133a-5p expression or rescuing FBXO6 expression may be promising strategies for the treatment of IVDD.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

This study suggests that the miR-133a-5p/FBXO6 axis could regulate NP cells proliferation, apoptosis, synthesis and degradation of extracellular matrix, which provides a promising therapeutic target and strategy for the treatment of IVDD.

Downregulation of circular RNA circDOCK7 identified from diabetic rats after sleeve gastrectomy contributes to hepatocyte apoptosis through regulating miR-139-3p and MCM3

Sleeve gastrectomy (SG) is the most widely used bariatric procedures globally, which could improve glucose and lipid metabolism dramatically. Circular RNAs (circRNAs) are being increasingly implicated in numerous pathophysiological processes. However, for diabetes mellitus (DM), the expression and function of circRNAs remain largely undetermined, in particular, whether circRNAs mediate the amelioration of DM observed after SG. Using a diabetic rat model, we subjected liver tissue from SG and sham-operated rats to RNA sequencing. Amongst the 103 differentially regulated circRNAs identified in diabetic rats after SG, we focused on circDOCK7, a highly expressed circRNA derived from the back-splicing of the DOCK7 gene. Silencing of circDOCK7 significantly inhibited cellular proliferation and induction of apoptosis in insulin-resistant rat hepatocytes. Further analysis indicated circDOCK7 harbored binding sites for miR-139-3p and regulated the expression of minichromosome maintenance 3 (MCM3) through sequestration of miR-139-3p. Our findings therefore demonstrate a novel regulatory pathway involving circDOCK7 that regulates cellular proliferation and apoptosis through increasing the expression of MCM3. Overall, our study establishes a list of specific circRNAs expressed in diabetic rat liver after SG including circDOCK7 which serve as potential biomarkers and treatment targets for DM patients.

Metabolic Reprogramming in Cancer: Role of HPV 16 Variants

Metabolic reprogramming is considered one of the hallmarks in cancer and is characterized by increased glycolysis and lactate production, even in the presence of oxygen, which leads the cancer cells to a process called “aerobic glycolysis” or “Warburg effect”. The E6 and E7 oncoproteins of human papillomavirus 16 (HPV 16) favor the Warburg effect through their interaction with a molecule that regulates cellular metabolism, such as p53, retinoblastoma protein (pRb), c-Myc, and hypoxia inducible factor 1α (HIF-1α). Besides, the impact of the E6 and E7 variants of HPV 16 on metabolic reprogramming through proteins such as HIF-1α may be related to their oncogenicity by favoring cellular metabolism modifications to satisfy the energy demands necessary for viral persistence and cancer development. This review will discuss the role of HPV 16 E6 and E7 variants in metabolic reprogramming and their contribution to developing and preserving the malignant phenotype of cancers associated with HPV 16 infection.

Silencing of Long Non-Coding RNA FGD5-AS1 Inhibits the Progression of Non-Small Cell Lung Cancer by Regulating the miR-493-5p/DDX5 Axis

Background:

Long non-coding RNA FGD5 antisense RNA 1 (FGD5-AS1), identified to be a carcinogenic lncRNA, exhibits a regulatory role in some malignancies including non-small cell lung cancer (NSCLC). The aim of the present research is to decipher the function and underlying mechanism of FGD5-AS1 in progression of NSCLC.

Methods:

Expression of FGD5-AS1, miR-493-5p and DEAD-box protein 5 (DDX5) in NSCLC tissues and cells was quantified utilizing qRT-PCR. Cell proliferation was assessed by CCK-8 method. Scratch healing test and Transwell assay were used for assaying cell migration and invasion. Expressions of DDX5 and epithelial-mesenchymal transition (EMT)-related proteins were examined by Western blot. Additionally, targeting relationships between FGD5-AS1 and miR-493-5p, miR-493-5p and DDX5 were verified by dual-luciferase reporter gene assay.

Results:

Expression of FGD5-AS1 in NSCLC tissues and cell lines was up-regulated. Expression of FGD5-AS1 was in association with enlarged tumor size and lymph node metastasis of the patients. Knockdown of FGD5-AS1 led to the inhibition of proliferation, migration, invasion and EMT of NSCLC cells. FGD5-AS1 directly targeted miR-493-5p, while DDX5 was the target of miR-493-5p in NSCLC cells. Additionally, FGD5-AS1 could positively regulate the expression of DDX5 via suppressing miR-493-5p.

Conclusion:

FGD5-AS1 facilitates the proliferation, migration, invasion and EMT of NSCLC cells by sponging miR-493-5p and up-regulating DDX5.

Hepatitis B virus P protein initiates glycolytic bypass in HBV-related hepatocellular carcinoma via a FOXO3/miRNA-30b-5p/MINPP1 axis

Background

Hepatitis B virus (HBV) infection is a crucial risk factor for hepatocellular carcinoma (HCC). However, its underlying mechanism remains understudied.

Methods

Microarray analysis was conducted to compare the genes and miRNAs in liver tissue from HBV-positive and HBV-negative HCC patients. Biological functions of these biomarkers in HBV-related HCC were validated via in vitro and in vivo experiments. Furthermore, we investigated the effect of HBV on the proliferation and migration of tumor cells in HBV-positive HCC tissue. Bioinformatics analysis was then performed to validate the clinical value of the biomarkers in a large HCC cohort.

Results

We found that a gene, MINPP1 from the glycolytic bypass metabolic pathway, has an important biological function in the development of HBV-positive HCC. MINPP1 is down-regulated in HBV-positive HCC and could inhibit the proliferation and migration of the tumor cells. Meanwhile, miRNA-30b-5p was found to be a stimulator for the proliferation of tumor cell through glycolytic bypass in HBV-positive HCC. More importantly, miRNA-30b-5p could significantly downregulate MINPP1 expression. Metabolic experiments showed that the miRNA-30b-5p/MINPP1 axis is able to accelerate the conversion of glucose to lactate and 2,3-bisphosphoglycerate (2,3-BPG). In the HBV-negative HCC cells, miRNA-30b-5p/MINPP1 could not regulate the glycolytic bypass to promote the tumorigenesis. However, once HBV was introduced into these cells, miRNA-30b-5p/MINPP1 significantly enhanced the proliferation, migration of tumor cells, and promoted the glycolytic bypass. We further revealed that HBV infection promoted the expression of miRNA-30b-5p through the interaction of HBV protein P (HBp) with FOXO3. Bioinformatics analysis on a large cohort dataset showed that high expression of MINPP1 was associated with favorable survival of HBV-positive HCC patients, which could lead to a slower progress of this disease.

Conclusion

Our study found that the HBp/FOXO3/miRNA-30b-5p/MINPP1 axis contributes to the development of HBV-positive HCC cells through the glycolytic bypass. We also presented miRNA-30b-5p/MINPP1 as a novel biomarker for HBV-positive HCC early diagnosis and a potential pharmaceutical target for antitumor therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-020-01803-8.

P53/miR-154 Pathway Regulates the Epithelial-Mesenchymal Transition in Glioblastoma Multiforme Cells by Targeting TCF12

PURPOSE

Glioblastoma multiforme (GBM) is an aggressive brain tumor with a rather short survival time. Mutation of p53 has been observed and reported to play critical roles in the progression of GBM. However, the pathological mechanisms are still unclear. This study was designed to identify the role of miR-154 in mediating the biological functions of p53 in glioblastoma multiforme.

METHODS

In the current study, the expression of miR-154 in GBM tissue samples and cell lines with wt-p53 or mutant p53 was evaluated. The functions of miR-154 in tumor migration, invasion and epithelial-mesenchymal transition were analyzed in vitro. A luciferase reporter assay was used to identify the target of miR-154.

RESULTS

We found that expression of miR-154 was much lower in patient tissues with mutant p53. Further study revealed that p53 was a transcription factor of miR-154 and that the R273H mutation led to its inactivation. In addition, overexpression of miR-154 remarkably suppressed cell migration, invasion and EMT in vitro and tumor growth in vivo. Moreover, TCF12 was proven to be a direct target of miR-154, and the tumor suppressive effect of miR-154 was reversed by TCF12.

CONCLUSION

Overall, miR-154, which was regulated by wt-p53, inhibited migration, invasion and EMT of GBM cells by targeting TCF12, indicating that miR-154 may act as a biomarker and that the p53/miR-154/TCF12 pathway could be a potential therapeutic target for GBM.

miR-429-3p/LPIN1 Axis Promotes Chicken Abdominal Fat Deposition via PPARγ Pathway

To explore the regulatory mechanism of abdominal fat deposition in broilers, 100-day-old Sanhuang chickens (n = 12) were divided into high-fat and low-fat groups, according to the abdominal fat ratio size. Total RNA isolated from the 12 abdominal fat tissues was used for miRNA and mRNA sequencing. Results of miRNA and mRNA sequencing revealed that miR-429-3p was highly expressed in high-fat chicken whereas LPIN1 expression was downregulated. Further, we determined that miR-429-3p promoted preadipocyte proliferation and differentiation, whereas LPIN1 exerted an opposite effect. Notably, we found that the miR-429-3p/LPIN1 axis facilitated PPARγ pathway activation, which is closely associated with the progression of adipogenesis. In conclusion, our results provide evidence that a novel miR-429-3p/LPIN1 axis is involved in the regulation of adipogenesis, which may have a guiding role in the improvement of breeding for abdominal fat traits in broiler chickens.

Establishing and validating a pathway prognostic signature in pancreatic cancer based on miRNA and mRNA sets using GSVA

Pancreatic cancer (PC) is a severe disease with the highest mortality rate among various cancers. It is urgent to find an effective and accurate way to predict the survival of PC patients. Gene set variation analysis (GSVA) was used to establish and validate a miRNA set-based pathway prognostic signature for PC (miPPSPC) and a mRNA set-based pathway prognostic signature for PC (mPPSPC) in independent datasets. An optimized miPPSPC was constructed by combining clinical parameters. The miPPSPC, optimized miPPSPC and mPPSPC were established and validated to predict the survival of PC patients and showed excellent predictive ability. Four metabolic pathways and one oxidative stress pathway were identified in the miPPSPC, whereas linoleic acid metabolism and the pentose phosphate pathway were identified in the mPPSPC. Key factors of the pentose phosphate pathway and linoleic acid metabolism, G6PD and CYP2C8/9/18/19, respectively, are related to the survival of PC patients according to our tissue microarray. Thus, the miPPSPC, optimized miPPSPC and mPPSPC can predict the survival of PC patients efficiently and precisely. The metabolic and oxidative stress pathways may participate in PC progression.

Exosomal miR-141 promotes tumor angiogenesis via KLF12 in small cell lung cancer

BACKGROUND

Angiogenesis, a basic requirement for tumor cell survival, is considered to be a malignant characteristic of small cell lung cancer (SCLC) and is closely related to the poor outcomes of SCLC patients. miR-141 has been found to play pro- and antiangiogenic roles in different cancers, but its role in SCLC angiogenesis has never been explored.

METHODS

Total RNA was isolated from plasm exosomes and serum of SCLC patients to examine the expression of miR-141 by qRT-PCR. Cell proliferation, invasion, migration, tube formation assay, aortic ring assay and mouse tumor model were used to investigate the effect of exosomal miR-141 in angiogenesis in vitro and in vivo. Dual-luciferase assay was conducted to explore the target gene of miR-141.

RESULTS

Circulating miR-141 was upregulated in samples from 122 SCLC patients compared with those from normal volunteers and that the increase in miR-141 was significantly associated with advanced TNM stages, implying the potential oncogenic role of miR-141 in SCLC malignancy. In vitro, miR-141 that was packaged into SCLC cell-secreted exosomes and delivered to human umbilical vein vascular endothelial cells (HUVECs) via exosomes facilitated HUVEC proliferation, invasion, migration and tube formation and promoted microvessel sprouting from mouse aortic rings. Matrigel plug assays demonstrated that SCLC cell-derived exosomal miR-141 induced neoangiogenesis in vivo. Furthermore, mouse subcutaneous tumor nodules that were developed from miR-141-overexpressing SCLC cells had a higher microvessel density (MVD) and grew faster than those developed from negative control cells. KLF12 was found to be the direct target gene of miR-141 and that the proangiogenic effect of miR-141 on HUVECs was abrogated by KLF12 overexpression.

CONCLUSIONS

Our results demonstrate the specific function of the exosomal miR-141/KLF12 pathway in SCLC angiogenesis for the first time and provide potential novel targets for antiangiogenic therapies for SCLC patients.

MiR-30b-5p inhibits proliferation and promotes apoptosis of medulloblastoma cells via targeting MYB proto-oncogene like 2 (MYBL2)

Medulloblastoma (MB) is the most common malignant brain tumors among children. MiR-30b-5p is a potential tumor suppressor in a variety of human cancers. However, its expression and function in MB remain poorly understood. This study aimed to investigate the expression, role and regulatory mechanism of miR-30b-5p in MB. The expression of miR-30b-5p in MB tissues and cell lines was detected by real-time PCR. The effects of miR-30b-5p on cell proliferation and apoptosis were monitored by CCK-8 (Cell Counting Kit-8) assay, colony formation assay and flow cytometry, respectively. Bioinformatics database TargetScan predicted the target genes of miR-30b-5p. The interaction between miR-30b-5p and MYB proto-oncogene Like 2 (MYBL2) was determined by luciferase reporter gene assay. We demonstrated that the expression of miR-30b-5p was significantly downregulated in MB. Upregulated miR-30b-5p could inhibit the proliferation and induce apoptosis of MB.

Moreover, overexpressed miR-30b-5p could increase the expression of BAX but decrease that of Bcl-2. Downregulated miR-30b-5p exerted the opposite effect. MYBL2 was proved to be the target gene of miR-30b-5p and was negatively regulated by miR-30b-5p. These results indicate that miR-30b-5p inhibits the progression of MB via targeting the expression of MYBL2.

Paeonol Inhibits Cell Proliferation, Migration and Invasion and Induces Apoptosis in Hepatocellular Carcinoma by Regulating miR-21-5p/KLF6 Axis

Background

Hepatocellular carcinoma (HCC) is one of the most common tumors with high mortality. MicroRNAs (miRNAs) were reported as crucial markers for the diagnosis of HCC. Paeonol exerted many pharmacological effects on tumor progression. This study aimed to elucidate the underlying molecular mechanism of paeonol in HCC progression.

Methods

Cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. Cell apoptosis was examined by flow cytometry. The levels of Cyclin D1, cyclin-dependent kinase 4 (CDK4), B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) were detected by Western blot assay. Cell migration and invasion were assessed by transwell assay. The levels of matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9) were measured by Western blot. The expression of miR-21-5p and kruppel-like factor 6 (KLF6) was detected by quantitative real-time PCR (qRT-PCR) or Western blot assay, respectively. Dual-luciferase reporter assay was performed to analyze the interaction between miR-21-5p and KLF6. The enrichment of miR-21-5p was determined by RNA pull-down assay. Xenograft assay was conducted to analyze tumor growth in vivo.

Results

The results demonstrated that cell viability of Hep3B and Huh-7 cells was inhibited, while cell apoptosis was promoted after treatment with paeonol. Transwell assay indicated that cell migration and invasion were blocked in paeonol-treated cells. Moreover, miR-21-5p expression was markedly decreased in paeonol-treated cells and its knockdown suppressed cell viability, migration and invasion, but contributed to cell apoptosis. MiR-21-5p targeted KLF6 and its silencing prominently elevated KLF6 level. Furthermore, the restoration experiment determined that miR-21-5p and KLF6 were antagonisms on cell viability, apoptosis, migration and invasion. Also, paeonol abated the decrease in KLF6 level caused by miR-21-5p up-regulation. Besides, paeonol suppressed tumor growth in vivo.

Conclusion

Paeonol impeded cell viability, migration and invasion and triggered apoptosis by regulating miR-21-5p/KLF6 axis in HCC cells. Xenograft assay confirmed that paeonol inhibited tumor growth through miR-21-5p/KLF6 axis in HCC in vivo.

Over-expression of miR-223 induces M2 macrophage through glycolysis alteration and attenuates LPS-induced sepsis mouse model, the cell-based therapy in sepsis

The attenuation of hyper-inflammation in sepsis with the administration of anti-inflammatory macrophages is an interesting adjuvant therapy for sepsis. Because the induction of anti-inflammatory macrophages by microRNA (miR), a regulator of mRNA, has been mentioned, the exploration on miR-induced anti-inflammatory macrophages was performed. The over-expression of miR-223 and miR-146a in RAW264.7 induced M2 macrophage-polarization (anti-inflammatory macrophages) as evaluated by the enhanced expression of Arginase-1 and Fizz. However, miR-223 over-expressed cells demonstrated the more potent anti-inflammatory property against LPS stimulation as lesser iNOS expression, lower supernatant IL-6 and higher supernatant IL-10 compared with miR-146a over-expressed cells. Interestingly, LPS stimulation in miR-223 over-expressed cells, compared with LPS-stimulated control cells, demonstrated lower activity of glycolysis pathway and higher mitochondrial respiration, as evaluated by the extracellular flux analysis, and also down-regulated HIF-1α, an important enzyme of glycolysis pathway. In addition, the administration of miR-223 over-expressed macrophages with IL-4 pre-conditioning, but not IL-4 stimulated control cells, attenuated sepsis severity in LPS injected mice as evaluated by serum creatinine, liver enzymes, lung histology and serum cytokines. In conclusion, miR-223 interfered with the glycolysis pathway through the down-regulation of HIF-1α, resulting in the anti-inflammatory status. The over-expression of miR-223 in macrophages prevented the conversion into M1 macrophage polarization after LPS stimulation. The administration of miR-223 over-expressed macrophages, with IL-4 preconditioning, attenuated sepsis severity in LPS model. Hence, a proof of concept in the induction of anti-inflammatory macrophages through the cell-energy interference for sepsis treatment was proposed as a basis of cell-based therapy in sepsis.

MiR-384 inhibits proliferation and migration of trophoblast cells via targeting PTBP3

Preeclampsia (PE) is one type of hypertension during pregnancy that seriously threatens maternal and infant health. Trophoblast dysfunction, such as decreased proliferation and migration, is closely related to the occurrence and development of PE. MicroRNAs (miRNAs) have been proven to play an important role in many diseases, including PE. miR-384 was reported to play a regulatory role in promoting cell apoptosis and inhibiting proliferation, migration and invasion in a variety of tumors. Previously, we found that miR-384 is upregulated in the placenta and plasma in the context of PE. In this study, we elucidated the function of miR-384 in the trophoblast cell line HTR-8/SVneo and the trophoblastic tumor cell line JEG-3. Cell proliferation and migration were inhibited by miR-384 overexpression but promoted by miR-384 downregulation. Subsequently, polypyrimidine tract-binding protein 3(PTBP3) was found to be a direct target gene of miR-384. PTBP3 was downregulated in placental tissues from PE patients, and a negative correlation was found between PTBP3 and miR-384. Our results suggest that the miR-384/PTBP3 axis plays an important role in regulating trophoblast function during the progression of PE, and these data provide novel insight into the molecular pathogenesis of this disorder.

miR-4999-5p Predicts Colorectal Cancer Survival Outcome and Reprograms Glucose Metabolism by Targeting PRKAA2

Purpose

Colorectal cancer (CRC) is the third most common cancer, and the second leading cause of cancer death worldwide. Dysregulation of microRNAs has been shown to modulate glucose metabolic reprogramming in CRC. However, the functional role of miR-4999-5p in the CRC glucose metabolic shift has not been characterized.

Patients and Methods

The levels of miR-4999-5p and PRKAA2 were evaluated by RT-qPCR. Univariate and multivariate survival analyses were conducted to evaluate the prognostic value of miR-4999-5p. Cell proliferation was assessed using the CCK-8 and colony formation assays. Extracellular acidification rate, glucose uptake, cellular glucose-6-phosphate level, and lactate production were evaluated to assess the effects of miR-4999-5p on CRC glycolysis. Dual-luciferase reporter assay was conducted to investigate the direct interaction between miR-4999-5p and PRKAA2. Mouse xenograft models were established to assess the functions of miR-4999-5p in vivo.

Results

miR-4999-5p was highly expressed in CRC tissues and cell lines. In addition, miR-4999-5p was associated with tumor differentiation and TNM stage, and elevated expression of miR-4999-5p was an independent predictor of poorer overall survival. Furthermore, miR-4999-5p promoted cell proliferation and glycolysis in CRC. miR-4999-5p targeted PRKAA2 to exert its tumor-promoting functions, and PRKAA2 knockdown rescued decreased cell proliferation and glycolysis in miR-4999-5p-silenced CRC cells. In vivo experiments showed that miR-4999-5p promoted CRC growth.

Conclusion

miR-4999-5p facilitated cell growth and glucose metabolic reprogramming through direct targeting of PRKAA2. Our results showed that miR-4999-5p may be a novel prognostic marker and therapeutic target for CRC.

Effect of gga-miR-155 on cell proliferation, apoptosis and invasion of Marek's disease virus (MDV) transformed cell line MSB1 by targeting RORA

BACKGROUND

Marek's disease (MD) is caused by the oncogenic Marek's disease virus (MDV), and is a highly contagious avian infection with a complex underlying pathology that involves lymphoproliferative neoplasm formation. MicroRNAs (miRNAs) act as oncogenes or tumor suppressors in most cancers. The gga-miR-155 is downregulated in the MDV-infected chicken tissues or lymphocyte lines, although its exact role in tumorigenesis remains unclear. The aim of this study was to analyze the effects of gga-miR-155 on the proliferation, apoptosis and invasiveness of an MDV-transformed lymphocyte line MSB1 and elucidate the underlying mechanisms.

RESULTS

The expression level of gga-miR-155 was manipulated in MSB1 cells using specific mimics and inhibitors. While overexpression of gga-miR-155 increased proliferation, decreased the proportion of G1 phase cells relative to that in S and G2 phases, reduced apoptosis rates and increased invasiveness. However, its downregulation had the opposite effects. Furthermore, gga-miR-155 directly targeted the RORA gene and downregulated its expression in the MSB1 cells.

CONCLUSION

The gga-miR-155 promotes the proliferation and invasiveness of the MDV-transformed lymphocyte line MSB1 and inhibits apoptosis by targeting the RORA gene.

LncRNA NNT-AS1 promotes non-small cell lung cancer progression through regulating miR-22-3p/YAP1 axis

Background

Lung cancer is the leading cause of cancer‐related mortality worldwide. Studies have demonstrated that long noncoding RNA nicotinamide nucleotide transhydrogenase‐antisense RNA1 (NNT‐AS1) functioned as an oncogene in most malignancies, including non‐small cell lung cancer (NSCLC). This study aimed to investigate the underlying mechanisms of NNT‐AS1 in NSCLC progression.

Methods

The levels of NNT‐AS1, miR‐22‐3p and Yes‐associated protein (YAP1) were detected by qRT‐PCR in NSCLC tissues and cells. Kaplan‐Meier analysis was conducted to analyze the correlation between NNT‐AS1 expression and overall survival of NSCLC patients. Cell proliferation was evaluated by MTT assay. Cell migration and invasion were assessed using transwell assay. The protein levels of YAP1 and EMT‐related proteins were detected by western blot. The molecular mechanism was predicted by starBase2.0 and validated by dual‐luciferase reporter assay or RNA pull‐down assay. Xenograft analysis was carried out to analyze tumor growth in vivo.

Results

We found that the levels of NNT‐AS1 and YAP1 were enhanced, while miR‐22‐3p expression was decreased in NSCLC tissues and cells. High NNT‐AS1 expression was correlated with poor prognosis. NNT‐AS1 knockdown impeded proliferation, migration, invasion and EMT of NSCLC cells. NNT‐AS1 targeted miR‐22‐3p, and YAP1 was a target of miR‐22‐3p in NSCLC cells. Furthermore, NNT‐AS1 facilitated the progression of NSCLC by regulating miR‐22‐3p/YAP1 axis. NNT‐AS1 knockdown repressed tumor growth in vivo.

Conclusion

NNT‐AS1 facilitated proliferation, migration, invasion and EMT of NSCLC cells by sponging miR‐22‐3p and regulating YAP1 expression, which might provide a potential biomarker and therapeutic target for NSCLC.

Rescue of TCA Cycle Dysfunction for Cancer Therapy

Mitochondrion, a maternally hereditary, subcellular organelle, is the site of the tricarboxylic acid (TCA) cycle, electron transport chain (ETC), and oxidative phosphorylation (OXPHOS)—the basic processes of ATP production. Mitochondrial function plays a pivotal role in the development and pathology of different cancers. Disruption in its activity, like mutations in its TCA cycle enzymes, leads to physiological imbalances and metabolic shifts of the cell, which contributes to the progression of cancer. In this review, we explored the different significant mutations in the mitochondrial enzymes participating in the TCA cycle and the diseases, especially cancer types, that these malfunctions are closely associated with. In addition, this paper also discussed the different therapeutic approaches which are currently being developed to address these diseases caused by mitochondrial enzyme malfunction.

Technological Challenges and Future Issues for the Detection of Circulating MicroRNAs in Patients With Cancer

In the era of precision medicine, the success of clinical trials, notably for patients diagnosed with cancer, strongly relies on biomarkers with pristine clinical value but also on robust and versatile analytical technologies to ensure proper patients' stratification and treatment. In this review, we will first address whether plasmatic and salivary microRNAs can be considered as a reliable source of biomarkers for cancer diagnosis and prognosis. We will then discuss the pre-analytical steps preceding miRNA quantification (from isolation to purification), and how such process could be biased and time-consuming. Next, we will review the most recent tools derived from micro- and nano-technologies for microRNA detection available to date and how they may compete with current standards. This review will prioritize publications using relevant biological samples. The significance of various physical transduction schemes (mechanical, optical, electrical, etc.) for biological detection will be compared, and pros and cons of each method will be widely discussed. Finally, we will debate on how micro and nanotechnologies could widespread the use of biomarkers in modern medicine, to help manage patients with serious diseases such as cancer.

Dichloroacetate (DCA) and Cancer: An Overview towards Clinical Applications

An extensive body of literature describes anticancer property of dichloroacetate (DCA), but its effective clinical administration in cancer therapy is still limited to clinical trials. The occurrence of side effects such as neurotoxicity as well as the suspicion of DCA carcinogenicity still restricts the clinical use of DCA. However, in the last years, the number of reports supporting DCA employment against cancer increased also because of the great interest in targeting metabolism of tumour cells. Dissecting DCA mechanism of action helped to understand the bases of its selective efficacy against cancer cells. A successful coadministration of DCA with conventional chemotherapy, radiotherapy, other drugs, or natural compounds has been tested in several cancer models. New drug delivery systems and multiaction compounds containing DCA and other drugs seem to ameliorate bioavailability and appear more efficient thanks to a synergistic action of multiple agents. The spread of reports supporting the efficiency of DCA in cancer therapy has prompted additional studies that let to find other potential molecular targets of DCA. Interestingly, DCA could significantly affect cancer stem cell fraction and contribute to cancer eradication. Collectively, these findings provide a strong rationale towards novel clinical translational studies of DCA in cancer therapy.

MiR-32-5p aggravates intestinal epithelial cell injury in pediatric enteritis induced by Helicobacter pylori

BACKGROUND

Pediatric enteritis is one of the infectious diseases in the digestive system that causes a variety of digestive problems, including diarrhea, vomiting, and bellyache in children. Clinically, Helicobacter pylori (H. pylori) infection is one of the common factors to cause pediatric enteritis. It has been demonstrated that aberrant expression of microRNAs (miRNAs) is found in gastrointestinal diseases caused by H. pylori, and we discovered a significant increase of miR-32-5p in H. pylori-related pediatric enteritis. However, the exact role of miR-32-5p in it is still unknown.

AIM

To investigate the role of aberrant miR-32-5p in pediatric enteritis induced by H. pylori.

METHODS

MiR-32-5p expression was detected by quantitative real time-polymerase chain reaction. The biological role of miR-32-5p in H. pylori-treated intestinal epithelial cells was evaluated by Cell Counting Kit-8 assay and flow cytometry. The potential target of miR-32-5p was predicted with TargetScanHuman and verified by luciferase assay. The downstream mechanism of miR-32-5p was explored by using molecular biology methods.

RESULTS

We found that miR-32-5p was overexpressed in serum of H. pylori-induced pediatric enteritis. Further investigation revealed that H. pylori infection promoted the death of intestinal epithelial cells, and increased miR-32-5p expression. Moreover, miR-32-5p mimic further facilitated apoptosis and inflammatory cytokine secretion of intestinal epithelial cells. Further exploration revealed that SMAD family member 6 (SMAD6) was the direct target of miR-32-5p, and SMAD6 overexpression partially rescued cell damage induced by H. pylori. The following experiments showed that miR-32-5p/SMAD6 participated in the apoptosis of intestinal epithelial cells induced by transforming growth factor-β-activated kinase 1 (TAK1)-p38 activation under H. pylori infection.

CONCLUSION

Our work uncovered the crucial role of aberrant expression of miR-32-5p in H. pylori–related pediatric enteritis, and suggested that the TAK1-p38 pathway is involved in it.

STAT3 Regulates miR-384 Transcription During Th17 Polarization

MicroRNAs are powerful regulators of gene expression in physiological and pathological conditions. We previously showed that the dysregulation of miR-384 resulted in a T helper cell 17 (Th17) imbalance and contributed to the pathogenesis of experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. In this study, we evaluated the molecular mechanisms underlying the abnormal increase in miR-384. We did not detect typical CpG islands in the Mir384 promoter. Based on a bioinformatics analysis of the promoter, we identified three conserved transcription factor binding regions (R_I, R_II, and R_III), two of which (R_II and R_III) were cis-regulatory elements. Furthermore, we showed that signal transducer and activator of transcription 3 (STAT3) bound to specific sites in R_II and R_III based on chromatin immunoprecipitation, electrophoretic mobility shift assays, and site-specific mutagenesis. During Th17 polarization in vitro, STAT3 activation up-regulated miR-384, while a STAT3 phosphorylation inhibitor decreased miR-384 levels and reduced the percentage of IL-17⁺ cells, IL-17 secretion, and expression of the Th17 lineage marker Rorγt. Moreover, the simultaneous inhibition of STAT3 and miR-384 could further block Th17 polarization. These results indicate that STAT3, rather than DNA methylation, contributes to the regulation of miR-384 during Th17 polarization.