MicroRNA-155-3p promotes hepatocellular carcinoma formation by suppressing FBXW7 expression

Molecular insights and clinical implications for the tumor suppressor role of SCFFBXW7 E3 ubiquitin ligase

FBXW7 is one of the most well-characterized F-box proteins, serving as substrate receptor subunit of SKP1-CUL1-F-box (SCF) E3 ligase complexes. SCFFBXW7 is responsible for the degradation of various oncogenic proteins such as cyclin E, c-MYC, c-JUN, NOTCH, and MCL1. Therefore, FBXW7 functions largely as a major tumor suppressor. In keeping with this notion, FBXW7 gene mutations or downregulations have been found and reported in many types of malignant tumors, such as endometrial, colorectal, lung, and breast cancers, which facilitate the proliferation, invasion, migration, and drug resistance of cancer cells. Therefore, it is critical to review newly identified FBXW7 regulation and tumor suppressor function under physiological and pathological conditions to develop effective strategies for the treatment of FBXW7-altered cancers. Since a growing body of evidence has revealed the tumor-suppressive activity and role of FBXW7, here, we updated FBXW7 upstream and downstream signaling including FBXW7 ubiquitin substrates, the multi-level FBXW7 regulatory mechanisms, and dysregulation of FBXW7 in cancer, and discussed promising cancer therapies targeting FBXW7 regulators and downstream effectors, to provide a comprehensive picture of FBXW7 and facilitate the study in this field.

Milk thistle nano-micelle formulation promotes cell cycle arrest and apoptosis in hepatocellular carcinoma cells through modulating miR-155-3p /SOCS2 /PHLDA1 signaling axis

BACKGROUND

Hepatocellular Carcinoma (HCC) is a prevalent form of liver cancer that causes significant mortality in numerous individuals worldwide. This study compared the effects of milk thistle (MT) and nano-milk thistle (N-MT) on the expression of the genes that participate in apoptosis and cell cycle pathways in Huh-7 and HepG2 cells.

METHODS

IC50 values of MT and N-MT were determined using the MTT assay. Huh-7 and HepG2 cell lines (containing mutant and wild-type TP53 gene, respectively) were incubated with MT and N-MT for 24h and 48h and the impact of MT and N-MT on the proliferation of these cell lines was evaluated through a comparative analysis. Cell cycle and apoptosis were assessed by flow cytometry after 24h and 48h treatment in the cell lines mentioned. Real-time PCR was used to analyze miR-155-3p, PHLDA1, SOCS2, TP53, P21, BAX, and BCL-2 expression in the cell lines that were being treated.

RESULTS

N-MT reduces cancer cell growth in a time and concentration-dependent manner, which is more toxic compared to MT. Huh-7 was observed to have IC50 values of 2.35 and 1.7 μg/ml at 24h and 48h, and HepG2 was observed to have IC50 values of 3.4 and 2.6 μg/ml at 24 and 48h, respectively. N-MT arrested Huh-7 and HepG2 cells in the Sub-G1 phase and induced apoptosis. N-MT led to a marked reduction in the expression of miR-155-3p and BCL-2 after 24h and 48h treatments. Conversely, PHLDA1, SOCS2, BAX, and P21 were upregulated in the treated cells compared to untreated cells, which suggests that milk thistle has the potential to regulate these genes. N-MT reduced the expression of TP53 in Huh-7 cells after mentioned time points, while there was a significant increase in the expression of the TP53 gene in HepG2 cells. No gene expression changes were observed in MT-treated cells after 24h and 48h.

CONCLUSION

N-MT can regulate cancer cell death by arresting cell cycle and inducing apoptosis. This occurs through the alteration of apoptotic genes expression. A reduction in the expression of miR-155-3p and increase in the expression of SOCS2 and PHLDA1 after N-MT treatment showed the correlation between miR-155-3p and PHLDA1/SOCS2 found in bioinformatics analysis. While N-MT increased TP53 expression in HepG2, reduced it in Huh-7. The findings indicate that N-MT can function intelligently in cancer cells and can be a helpful complement to cancer treatment.

EBV and 1q Gains Affect Gene and miRNA Expression in Burkitt Lymphoma

Abnormalities of the long arm of chromosome 1 (1q) represent the most frequent secondary chromosomal aberrations in Burkitt lymphoma (BL) and are observed almost exclusively in EBV-negative BL cell lines (BL-CLs). To verify chromosomal abnormalities, we cytogenetically investigated EBV-negative BL patient material, and to elucidate the 1q gain impact on gene expression, we performed qPCR with six 1q-resident genes and analyzed miRNA expression in BL-CLs. We observed 1q aberrations in the form of duplications, inverted duplications, isodicentric chromosome idic(1)(q10), and the accumulation of 1q12 breakpoints, and we assigned 1q21.2-q32 as a commonly gained region in EBV-negative BL patients. We detected MCL1, ARNT, MLLT11, PDBXIP1, and FCRL5, and 64 miRNAs, showing EBV- and 1q-gain-dependent dysregulation in BL-CLs. We observed MCL1, MLLT11, PDBXIP1, and 1q-resident miRNAs, hsa-miR-9, hsa-miR-9*, hsa-miR-92b, hsa-miR-181a, and hsa-miR-181b, showing copy-number-dependent upregulation in BL-CLs with 1q gains. MLLT11, hsa-miR-181a, hsa-miR-181b, and hsa-miR-183 showed exclusive 1q-gains-dependent and FCRL5, hsa-miR-21, hsa-miR-155, hsa-miR-155*, hsa-miR-221, and hsa-miR-222 showed exclusive EBV-dependent upregulation. We confirmed previous data, e.g., regarding the EBV dependence of hsa-miR-17-92 cluster members, and obtained detailed information considering 1q gains in EBV-negative and EBV-positive BL-CLs. Altogether, our data provide evidence for a non-random involvement of 1q gains in BL and contribute to enlightening and understanding the EBV-negative and EBV-positive BL pathogenesis.

FBXW7 attenuates tumor drug resistance and enhances the efficacy of immunotherapy

FBXW7 (F-box and WD repeat domain containing 7) is a critical subunit of the Skp1-Cullin1-F-box protein (SCF), acting as an E3 ubiquitin ligase by ubiquitinating targeted protein. Through degradation of its substrates, FBXW7 plays a pivotal role in drug resistance in tumor cells and shows the potential to rescue the sensitivity of cancer cells to drug treatment. This explains why patients with higher FBXW7 levels exhibit higher survival times and more favorable prognosis. Furthermore, FBXW7 has been demonstrated to enhance the efficacy of immunotherapy by targeting the degradation of specific proteins, as compared to the inactivated form of FBXW7. Additionally, other F-box proteins have also shown the ability to conquer drug resistance in certain cancers. Overall, this review aims to explore the function of FBXW7 and its specific effects on drug resistance in cancer cells.

Influence of the Mediterranean Diet on Healthy Aging

The life expectancy of the global population has increased. Aging is a natural physiological process that poses major challenges in an increasingly long-lived and frail population. Several molecular mechanisms are involved in aging. Likewise, the gut microbiota, which is influenced by environmental factors such as diet, plays a crucial role in the modulation of these mechanisms. The Mediterranean diet, as well as the components present in it, offer some proof of this. Achieving healthy aging should be focused on the promotion of healthy lifestyle habits that reduce the development of pathologies that are associated with aging, in order to increase the quality of life of the aging population. In this review we analyze the influence of the Mediterranean diet on the molecular pathways and the microbiota associated with more favorable aging patterns, as well as its possible role as an anti-aging treatment.

Trading places: Peptide and small molecule alternatives to oligonucleotide-based modulation of microRNA expression

It is well established that microRNA (miRNA) dysregulation is involved in the development and progression of various diseases, especially cancer. Emerging evidence suggests that small molecule and peptide agents can interfere with miRNA disease pathways. Despite this, very little is known about structural features that drive drug-miRNA interactions and subsequent inhibition. In this review, we highlight the advances made in the development of small molecule and peptide inhibitors of miRNA processing. Specifically, we attempt to draw attention to peptide features that may be critical for interaction with the miRNA secondary structure to regulate miRNA expression. We hope that this review will help to establish peptides as exciting miRNA expression modulators and will contribute towards the development of the first miRNA-targeting peptide therapy.

SARS-CoV-2 RNAs are processed into 22-nt vsRNAs in Vero cells

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the global pandemic, resulting in great fatalities around the world. Although the antiviral roles of RNA interference (RNAi) have been well studied in plants, nematodes and insects, the antiviral roles of RNAi in mammalians are still debating as RNAi effect is suspected to be suppressed by interferon (IFN) signaling pathways in most cell types. To determine the role of RNAi in mammalian resistance to SARS-CoV-2, we studied the profiling of host small RNAs and SARS-CoV-2 virus-derived small RNAs (vsRNAs) in the early infection stages of Vero cells, an IFN-deficient cell line. We found that host microRNAs (miRNAs) were dysregulated upon SARS-CoV-2 infection, resulting in downregulation of microRNAs playing antiviral functions and upregulation of microRNAs facilitating viral proliferations. Moreover, vsRNA peaked at 22 nt at negative strand but not the positive strand of SARS-CoV-2 and formed successive Dicer-spliced pattern at both strands. Similar characteristics of vsRNAs were observed in IFN-deficient cell lines infected with Sindbis and Zika viruses. Together, these findings indicate that host cell may deploy RNAi pathway to combat SARS-CoV-2 infection in IFN-deficient cells, informing the alternative antiviral strategies to be developed for patients or tissues with IFN deficiency.

The Key Role of microRNAs in Initiation and Progression of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the main type of primary liver malignancy and the fourth leading cause of cancer-related death worldwide. MicroRNAs (miRNAs), a type of non-coding RNA that regulates gene expression mainly on post-transcriptional level has a confirmed and important role in numerous biological process. By regulating specific target genes, miRNA can act as oncogene or tumor suppressor. Recent evidence has indicated that the deregulation of miR-NAs is closely associated with the clinical pathological features of HCC. However, the precise regulatory mechanism of each miRNA and its targets in HCC has yet to be illuminated. This study demonstrates that both oncogenic and tumor suppressive miRNAs are crucial in the formation and development of HCC. miRNAs influence biological behavior including proliferation, invasion, metastasis and apoptosis by targeting critical genes. Here, we summarize current knowledge about the expression profile and function of miRNAs in HCC and discuss the potential for miRNA-based therapy for HCC.

miR-155-3p: processing by-product or rising star in immunity and cancer?

MicroRNAs (miRNAs) are key players in gene regulation that target specific mRNAs for degradation or translational repression. Each miRNA is synthesized as a miRNA duplex comprising two strands (5p and 3p). However, only one of the two strands becomes active and is selectively incorporated into the RNA-induced silencing complex in a process known as miRNA strand selection. Recently, significant progress has been made in understanding the factors and processes involved in strand selection. Here, we explore the selection and functionality of the miRNA star strand (either 5p or 3p), which is generally present in the cell at low levels compared to its partner strand and, historically, has been thought to possess no biological activity. We also highlight the concepts of miRNA arm switching and miRNA isomerism. Finally, we offer insights into the impact of aberrant strand selection on immunity and cancer. Leading us through this journey is miR-155, a well-established regulator of immunity and cancer, and the increasing evidence that its 3p strand plays a role in these arenas. Interestingly, the miR-155-5p/-3p ratio appears to vary dependent on the timing of the immune response, and the 3p strand seems to play a regulatory role upon its partner 5p strand.

Clinical significance of FBXW7 loss of function in human cancers

FBXW7 (F-Box and WD Repeat Domain Containing 7) (also referred to as FBW7 or hCDC4) is a component of the Skp1-Cdc53 / Cullin-F-box-protein complex (SCF/β-TrCP). As a member of the F-box protein family, FBXW7 serves a role in phosphorylation-dependent ubiquitination and proteasome degradation of oncoproteins that play critical role(s) in oncogenesis. FBXW7 affects many regulatory functions involved in cell survival, cell proliferation, tumor invasion, DNA damage repair, genomic instability and telomere biology. This thorough review of current literature details how FBXW7 expression and functions are regulated through multiple mechanisms and how that ultimately drives tumorigenesis in a wide array of cell types. The clinical significance of FBXW7 is highlighted by the fact that FBXW7 is frequently inactivated in human lung, colon, and hematopoietic cancers. The loss of FBXW7 can serve as an independent prognostic marker and is significantly correlated with the resistance of tumor cells to chemotherapeutic agents and poorer disease outcomes. Recent evidence shows that genetic mutation of FBXW7 differentially affects the degradation of specific cellular targets resulting in a distinct and specific pattern of activation/inactivation of cell signaling pathways. The clinical significance of FBXW7 mutations in the context of tumor development, progression, and resistance to therapies as well as opportunities for targeted therapies is discussed.

Potential plasma biomarkers: miRNA-29c, miRNA-21, and miRNA-155 in clinical progression of Hepatocellular Carcinoma patients

This study evaluated differences in the clinical appearance of patients with hepatocellular carcinoma (HCC) based on plasma level and regulation of microRNAs (miRNA-29c, miRNA-21, and miRNA-155). The observational-analytical study with a cross-sectional design was conducted on 36 HCC patients and 36 healthy controls. The blood samples were collected from 2 Province Hospitals (Dr. Sardjito Hospital and Prof. Dr. Margono Soekarjo Hospital) for HCC and the Blood Bank Donor of the Indonesian Red Cross for 36 healthy controls. These blood samples were treated as follows: plasma isolation, RNA isolation, cDNA synthesis, quantification by qRT-PCR using a sequence-specific forward primer, and normalization of miRNA using housekeeping-stably miRNA-16. There were only 27 HCC patients with complete clinical variables (neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), platelet count, albumin, C-reactive protein (CRP), and cholinesterase (ChE)) that were able to analyses for regulation miRNAs based on its fold change expression miRNA target. All 27 HCC subjects were follow-up until 3-years of monitoring for their overall survival. The miRNA plasma expression was analyzed by Bio-Rad CFX 96 Manager software to determine the cycle of quantification, followed by the calculation of expression levels using Livak’s methods. Data were analyzed using STATA 11.0, with a significant value of p<0.05. The miRNAs expression of HCC subjects were lower than that healthy control subjects in miRNA-29c (down-regulation 1.83-fold), higher than that healthy control subjects in miRNA 21 and miRNA-155 (up-regulation, 1.74-fold; 1.55-fold) respectively. NLR, CRP, ChE, and platelet count showed a significant difference in miRNA-29c regulation, though neutrophil count showed a significant difference in miRNA-21 and miRNA-155 regulation (p<0.05). Conclusion: Plasma biomarkers: miRNA-21 and miRNA-155 might be potential biomarkers as onco-miR in HCC subjects, while miRNA-29c might act as a tumor suppressor. Significant evidence was identified with clinical progression based on the regulation of miRNAs, which was consistent with miRNA -29c.

microRNA-155-3p delivered by M2 macrophages-derived exosomes enhances the progression of medulloblastoma through regulation of WDR82

Objective

Exosomes, membranous nanovesicles, naturally bringing proteins, mRNAs, and microRNAs (miRNAs), play crucial roles in tumor pathogenesis. This study was to investigate the role of miR-155-3p from M2 macrophages-derived exosomes (M2-Exo) in promoting medulloblastoma (MB) progression by mediating WD repeat domain 82 (WDR82).

Methods

miR-155-3p expression was detected by RT-qPCR. The relationship of miR-155-3p with clinicopathological features of MB patients was analyzed. M2-Exo were isolated and identified by TEM, NTA and Western blot. CCK-8 assay, colony formation assay, flow cytometry, wound healing assay, and Transwell assay were performed to explore the role of miR-155-3p-enriched M2-Exo on the progression of MB cells. Luciferase assay were used to identify the relationship between miR-155-3p and WDR82. The effect of miR-155-3p-enriched M2-Exo on tumorigenesis of MB was confirmed by the xenograft nude mice model.

Results

miR-155-3p was up-regulated in MB tissues of patients and MB cell lines. High miR-155-3p expression was correlated with the pathological type and molecular subtype classification of MB patients. WDR82 was a direct target of miR-155-3p. miR-155-3p was packaged into M2-Exo. miR-155-3p-enriched M2-Exo promoted the progression of Daoy cells. miR-155-3p-enriched M2-Exo promoted in vivo tumorigenesis.

Conclusion

The study highlights that miR-155-3p-loaded M2-Exo enhances the growth of MB cells via down-regulating WDR82, which might provide a deep insight into MB mechanism.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03156-y.

NAFLD and Vitamin D: Evidence for Intersection of MicroRNA Regulated Pathways

Non-alcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease, worldwide. The molecular pathogenesis of NAFLD is complex, involving numerous signalling molecules including microRNAs (miRNAs). Dysregulation of miRNA expression is associated with hepatic inflammation, fibrosis and hepatocellular carcinoma. Although miRNAs are also critical to the cellular response to vitamin D, mediating regulation of the vitamin D receptor (VDR) and vitamin D’s anticancer effects, a role for vitamin D regulated miRNAs in NAFLD pathogenesis has been relatively unexplored. Therefore, this review aimed to critically assess the evidence for a potential subset of miRNAs that are both dysregulated in NAFLD and modulated by vitamin D. Comprehensive review of 89 human studies identified 25 miRNAs found dysregulated in more than one NAFLD study. In contrast, only 17 studies, including a protocol for a trial in NAFLD, had examined miRNAs in relation to vitamin D status, response to supplementation, or vitamin D in the context of the liver. This paper summarises these data and reviews the biological roles of six miRNAs (miR-21, miR-30, miR-34, miR-122, miR-146, miR-200) found dysregulated in multiple independent NAFLD studies. While modulation of miRNAs by vitamin D has been understudied, integrating the data suggests seven vitamin D modulated miRNAs (miR-27, miR-125, miR-155, miR-192, miR-223, miR-375, miR-378) potentially relevant to NAFLD pathogenesis. Our summary tables provide a significant resource to underpin future hypothesis-driven research, and we conclude that the measurement of serum and hepatic miRNAs in response to vitamin D supplementation in larger trials is warranted.

Implications of FBXW7 in Neurodevelopment and Neurodegeneration: Molecular Mechanisms and Therapeutic Potential

The ubiquitin-proteasome system (UPS) mediated protein degradation is crucial to maintain quantitive and functional homeostasis of diverse proteins. Balanced cellular protein homeostasis controlled by UPS is fundamental to normal neurological functions while impairment of UPS can also lead to some neurodevelopmental and neurodegenerative disorders. Functioning as the substrate recognition component of the SCF-type E3 ubiquitin ligase, FBXW7 is essential to multiple aspects of cellular processes via targeting a wide range of substrates for proteasome-mediated degradation. Accumulated evidence shows that FBXW7 is fundamental to neurological functions and especially implicated in neurodevelopment and the nosogenesis of neurodegeneration. In this review, we describe general features of FBXW7 gene and proteins, and mainly present recent findings that highlight the vital roles and molecular mechanisms of FBXW7 in neurodevelopment such as neurogenesis, myelination and cerebral vasculogenesis and in the pathogenesis of some typical neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. Additionally, we also provide a prospect on focusing FBXW7 as a potential therapeutic target to rescue neurodevelopmental and neurodegenerative impairment.

Mediterranean diet and the hallmarks of ageing

Ageing is a multifactorial process associated with reduced function and increased risk of morbidity and mortality. Recently, nine cellular and molecular hallmarks of ageing have been identified, which characterise the ageing process, and collectively, may be key determinants of the ageing trajectory. These include genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion and altered intercellular communication. Healthier dietary patterns reduce the risk of age-related diseases and increase longevity and may influence positively one or more of these hallmarks. The Mediterranean dietary pattern (MedDiet) is a plant-based eating pattern that was typical of countries such as Greece, Spain, and Italy pre-globalisation of the food system and which is associated with better health during ageing. Here we review the potential effects of a MedDiet on each of the nine hallmarks of ageing, and provide evidence that the MedDiet as a whole, or individual elements of this dietary pattern, may influence each hallmark positively-effects which may contribute to the beneficial effects of this dietary pattern on age-related disease risk and longevity. We also highlight potential avenues for future research.

Pasteurized non-fermented cow's milk but not fermented milk is a promoter of mTORC1-driven aging and increased mortality

Recent epidemiological studies in Sweden, a country with traditionally high milk consumption, revealed that the intake of non-fermented pasteurized milk increased all-cause mortality in a dose-dependent manner. In contrast, the majority of epidemiological and clinical studies report beneficial health effects of fermented milk products, especially of yogurt. It is the intention of this review to delineate potential molecular aging mechanisms related to the intake of non-fermented milk versus yogurt on the basis of mechanistic target of rapamycin complex 1 (mTORC1) signaling. Non-fermented pasteurized milk via its high bioavailability of insulinotropic branched-chain amino acids (BCAAs), abundance of lactose (glucosyl-galactose) and bioactive exosomal microRNAs (miRs) enhances mTORC1 signaling, which shortens lifespan and increases all-cause mortality. In contrast, fermentation-associated lactic acid bacteria metabolize BCAAs and degrade galactose and milk exosomes including their mTORC1-activating microRNAs. The Industrial Revolution, with the introduction of pasteurization and refrigeration of milk, restricted the action of beneficial milk-fermenting bacteria, which degrade milk's BCAAs, galactose and bioactive miRs that synergistically activate mTORC1. This unrecognized behavior change in humans after the Neolithic revolution increased aging-related over-activation of mTORC1 signaling in humans, who persistently consume large quantities of non-fermented pasteurized cow's milk, a potential risk factor for aging and all-cause mortality.

Up-regulation of miR-155 potentiates CD34+ CML stem/progenitor cells to escape from the growth-inhibitory effects of TGF-ß1 and BMP signaling

microRNAs (miRNAs or miRs) play key roles in different stages of chronic myeloid leukemia (CML) pathogenesis. The present study aimed to demonstrate whether miR-155 enables CD34⁺ CML cells to escape from the growth-inhibitory effects of TGF-β1 and bone morphogenetic protein (BMP) signaling. Among differentially expressed miRNAs in CD34⁺ CML cells, miR-155 was highly up-regulated. QRT-PCR revealed an inverse correlation between miR-155 and two key members of the TGF-β pathway-TGF-βR2 and SMAD5. Results showed that SMAD5 is not only up-regulated through BMPs treatment, but recombinant TGF-β1 can also induce SMAD5 in CML cells. We also demonstrated that TGF-β1-mediated phosphorylation of SMAD1/5 was abolished by pre-treatment with the blocking TGF-βR2 antibody, suggesting a possible involvement of TGF-βR2. Additionally, overexpression of miR-155 significantly promoted the proliferation rate of CD34⁺ CML cells. Results showed that siRNA-mediated knockdown of SMAD5 had a promoting effect on CD34⁺ CML cell proliferation, suggesting that SMAD5 knock-down recapitulates the proliferative effects of miR-155. Importantly, TGF-β1 and BMP2/4 treatment had inhibitory effects on cell proliferation; however, miR-155 overexpression enabled CD34⁺ CML cells to evade the anti-proliferative effects of TGF-β1 and BMPs. Consistently, down-regulation of miR-155 augmented the promoting effects of TGF-β1 and BMP signaling on inducing apoptosis in CD34⁺ CML stem cells. Our findings demonstrated that targeting of SMAD5 and TGF-βR2 links miR-155 to TGF-β signaling in CML. Overexpression of miR-155 enables CD34⁺ CML cells to evade growth-inhibitory effects of the TGF-β1 and BMP signaling, providing new perspectives for miR-155 as a therapeutic target for CML.

Hypoxic glioma-derived exosomes promote M2-like macrophage polarization by enhancing autophagy induction

Exosomes participate in intercellular communication and glioma microenvironment modulation, but the exact mechanisms by which glioma-derived exosomes (GDEs) promote the generation of the immunosuppressive microenvironment are still unclear. Here, we investigated the effects of GDEs on autophagy, the polarization of tumor-associated macrophages (TAMs), and glioma progression. Compared with normoxic glioma-derived exosomes (N-GDEs), hypoxic glioma-derived exosomes (H-GDEs) markedly facilitated autophagy and M2-like macrophage polarization, which subsequently promoted glioma proliferation and migration in vitro and in vivo. Western blot and qRT-PCR analyses indicated that interleukin 6 (IL-6) and miR-155-3p were highly expressed in H-GDEs. Further experiments showed that IL-6 and miR-155-3p induced M2-like macrophage polarization via the IL-6-pSTAT3-miR-155-3p-autophagy-pSTAT3 positive feedback loop, which promotes glioma progression. Our study clarifies a mechanism by which hypoxia and glioma influence autophagy and M2-like macrophage polarization via exosomes, which could advance the formation of the immunosuppressive microenvironment. Our findings suggest that IL-6 and miR-155-3p may be novel biomarkers for diagnosing glioma and that treatments targeting autophagy and the STAT3 pathway may contribute to antitumor immunotherapy.

Dairy consumption and hepatocellular carcinoma risk

This review provides epidemiological and translational evidence for milk and dairy intake as critical risk factors in the pathogenesis of hepatocellular carcinoma (HCC). Large epidemiological studies in the United States and Europe identified total dairy, milk and butter intake with the exception of yogurt as independent risk factors of HCC. Enhanced activity of mechanistic target of rapamycin complex 1 (mTORC1) is a hallmark of HCC promoted by hepatitis B virus (HBV) and hepatitis C virus (HCV). mTORC1 is also activated by milk protein-induced synthesis of hepatic insulin-like growth factor 1 (IGF-1) and branched-chain amino acids (BCAAs), abundant constituents of milk proteins. Over the last decades, annual milk protein-derived BCAA intake increased 3 to 5 times in Western countries. In synergy with HBV- and HCV-induced secretion of hepatocyte-derived exosomes enriched in microRNA-21 (miR-21) and miR-155, exosomes of pasteurized milk as well deliver these oncogenic miRs to the human liver. Thus, milk exosomes operate in a comparable fashion to HBV- or HCV- induced exosomes. Milk-derived miRs synergistically enhance IGF-1-AKT-mTORC1 signaling and promote mTORC1-dependent translation, a meaningful mechanism during the postnatal growth phase, but a long-term adverse effect promoting the development of HCC. Both, dietary BCAA abundance combined with oncogenic milk exosome exposure persistently overstimulate hepatic mTORC1. Chronic alcohol consumption as well as type 2 diabetes mellitus (T2DM), two HCC-related conditions, increase BCAA plasma levels. In HCC, mTORC1 is further hyperactivated due to RAB1 mutations as well as impaired hepatic BCAA catabolism, a metabolic hallmark of T2DM. The potential HCC-preventive effect of yogurt may be caused by lactobacilli-mediated degradation of BCAAs, inhibition of branched-chain α-ketoacid dehydrogenase kinase via production of intestinal medium-chain fatty acids as well as degradation of milk exosomes including their oncogenic miRs. A restriction of total animal protein intake realized by a vegetable-based diet is recommended for the prevention of HCC.

Lifetime Impact of Cow's Milk on Overactivation of mTORC1: From Fetal to Childhood Overgrowth, Acne, Diabetes, Cancers, and Neurodegeneration

The consumption of cow's milk is a part of the basic nutritional habits of Western industrialized countries. Recent epidemiological studies associate the intake of cow's milk with an increased risk of diseases, which are associated with overactivated mechanistic target of rapamycin complex 1 (mTORC1) signaling. This review presents current epidemiological and translational evidence linking milk consumption to the regulation of mTORC1, the master-switch for eukaryotic cell growth. Epidemiological studies confirm a correlation between cow's milk consumption and birthweight, body mass index, onset of menarche, linear growth during childhood, acne vulgaris, type 2 diabetes mellitus, prostate cancer, breast cancer, hepatocellular carcinoma, diffuse large B-cell lymphoma, neurodegenerative diseases, and all-cause mortality. Thus, long-term persistent consumption of cow's milk increases the risk of mTORC1-driven diseases of civilization. Milk is a highly conserved, lactation genome-controlled signaling system that functions as a maternal-neonatal relay for optimized species-specific activation of mTORC1, the nexus for regulation of eukaryotic cell growth, and control of autophagy. A deeper understanding of milk´s impact on mTORC1 signaling is of critical importance for the prevention of common diseases of civilization.

Exosomal microRNA-155 as a biomarker for hepatic fibrosis diagnosis and progression

Background

Pathological examination of liver biopsies remains the gold standard for evaluating the stage of hepatic fibrosis, which are a number of disadvantages associated with biopsy. The aim of the present study was to investigate the potential of exosomal microRNA (miR)-155 as a non-invasive biomarker for the diagnosis and progression of hepatic fibrosis.

Methods

Exosomal miR-155 quantity was analyzed by sampling serum exosomes of patients with hepatic fibrosis and a hepatic fibrosis rat model. A total of 94 patients were divided into three groups based on Child-Pugh rating. Additionally, 30 patients with primary liver fibrosis who underwent liver transplantation were divided into the low miR-155 expression group and the high expression group; 56 rats were divided into 7 groups (n=8, 0, 2, 4, 6, 8, 10, and 12 weeks). Rats in every group were intravenously injected with CCl4 (3% vol/vol in olive oil; 0.3 mL/100 g body weight) twice weekly to produce different degrees of liver necrosis and liver fibrosis.

Results

Exosomal miR-155 was found to be closely associated with the progression of cirrhosis and clinical prognostic indicators of cirrhosis. Exosomal miR-155 gradually increased with the severity of hepatic necrosis and fibrosis.

Conclusions

The findings of the present study indicate that exosomal miR-155 can act as a non-invasive biomarker for the diagnosis and progression of hepatic fibrosis.

In situ self-assembly of Au-antimiR-155 nanocomplexes mediates TLR3-dependent apoptosis in hepatocellular carcinoma cells

MicroRNA 155 (miRNA-155) is frequently dysregulated in hepatocellular carcinoma (HCC) and other cancer types. Toll-like receptor 3 (TLR3), a putative miR-155 target, plays a key role in liver pathophysiology, and its downregulation in HCC cells is associated with apoptosis evasion and poor outcomes. Herein, we examined the ability of in situ self-assembled Au-antimiR-155 nanocomplexes (Au-antimiRNA NCs) to activate TLR3 signaling in HCC cells. Gene expression analysis confirmed an inverse relationship between miR-155 and TLR3 expression in HCC samples, and marked upregulation of miR-155 was observed in HCC cells but not in normal L02 hepatocytes. RNA immunoprecipitation confirmed physical interaction between miR-155 and TLR3, while negative regulation of TLR3 expression by miR-155 was demonstrated by luciferase reporter assays. Au-antimiR-155 NCs were self-assembled within HepG2 HCC cells, but not within control L02 cells. They efficiently silenced miR-155, thereby inhibiting proliferation and migration and inducing apoptosis in HepG2 cells. Molecular analyses suggested these effects are secondary to TLR3 signaling mediating NF-κB transcription, caspase-8 activation, and interleukin-1β (IL-1β) release. Our results provide a basis for future studies examining the in vivo applicability of this novel Au-antimiRNA NCs delivery system to halt HCC progression by activating pro-apoptotic TLR3 signaling.

ARID2 Chromatin Remodeler in Hepatocellular Carcinoma

Chromatin remodelers are found highly mutated in cancer including hepatocellular carcinoma. These mutations frequently occur in ARID (AT-rich Interactive Domain) genes, encoding subunits of the ATP-dependent SWI/SNF remodelers. The increasingly prevalent complexity that surrounds the functions and specificities of the highly modular BAF (BG1/BRM-associated factors) and PBAF (polybromo-associated BAF) complexes, including ARID1A/B or ARID2, is baffling. The involvement of the SWI/SNF complexes in diverse tissues and processes, and especially in the regulation of gene expression, multiplies the specific outcomes of specific gene alterations. A better understanding of the molecular consequences of specific mutations impairing chromatin remodelers is needed. In this review, we summarize what we know about the tumor-modulating properties of ARID2 in hepatocellular carcinoma.

Tumor-suppressor miRNA-27b-5p regulates the growth and metastatic behaviors of ovarian carcinoma cells by targeting CXCL1

Background

MicroRNAs (miRNAs) play crucial functions in the progression of ovarian cancer. MicroRNA-27b-5p (miR-27b-5p) has been identified as a cancer-associated miRNA. Nevertheless, the expression profile of miR-27b-5p and its functions in ovarian cancer are unexplored.

Methods

qRT-PCR and western blot analysis were used to detect the levels of miR-27b-5p and C-X-C motif chemokine ligand 1 (CXCL1). The impact of miR-27b-5p on ovarian cancer cells proliferation, migration and invasion in vitro were investigated using Cell Counting Kit-8 (CCK8), wound healing and Transwell, respectively. The expression of matrix metalloprotein-2/9 (MMP-2/9) were measured using immunofluorescence staining. Bioinformatics and luciferase reporter analysis were used to predict the target of miR-27b-5p. The growth of ovarian cancer cells in vivo was evaluated using transplanted tumor model.

Results

Here, we demonstrated that miR-27b-5p was downregulated in ovarian carcinoma cells and clinical specimens. Higher expression of miR-27b-5p was associated with an unfavorable overall survival in patients with ovarian cancer. Upregulation of miR-27b-5p decreased the viability, migration ability and invasion capacity of SKOV3 and OVCAR3 cell. MiR-27b-5p also inhibited the growth of SKOV3 cell in nude mice. Additionally, we verified that CXCL1 was a target of miR-27b-5p in ovarian carcinoma cells. Restoring the expression of CXCL1 abolished the inhibitory impacts of miR-27b-5p in ovarian cancer carcinoma cells.

Conclusion

This research revealed that miR-27b-5p restrained the progression of ovarian carcinoma possibly via targeting CXCL1.

Long non-coding RNA SATB2-AS1 inhibits microRNA-155-3p to suppress breast cancer cell growth by promoting breast cancer metastasis suppressor 1-like

Background

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) play vital roles in human cancers. Nevertheless, the effects of lncRNAs and miRNAs on breast cancer (BC) remain to be further investigated. This study was designed to testify the roles of lncRNA antisense transcript of SATB2 protein (SATB2-AS1) and microRNA-155-3p (miR-155-3p) in BC progression.

Methods

Levels of SATB2-AS1, miR-155-3p and breast cancer metastasis suppressor 1-like (BRMS1L) in BC were determined. The prognostic role of SATB2-AS1 in BC patients was assessed. The screened cells were respectively introduced with altered SATB2-AS1 or miR-155-3p to figure out their roles in malignant phenotypes of BC cells. The effect of varied SATB2-AS1 and miR-155-3p on BC cells in vivo was observed. Dual luciferase reporter gene assay and RNA-pull down assay were implemented to detect the targeting relationship of SATB2-AS1, miR-155-3p, and BRMS1L.

Results

SATB2-AS1 and BRMS1L were decreased while miR-155-3p was increased in BC cells and tissues. Patients with lower SATB2-AS1 expression had poor prognosis. Elevated SATB2-AS1 and inhibited miR-155-3p were able to restrain malignant behaviors of BC cells in vitro, as well as decelerate tumor growth in vivo. Oppositely, inhibited SATB2-AS1 and amplified miR-155-3p had converse effects on BC cell growth. MiR-155-3p mimic abrogated the impact of overexpressed SATB2-AS1. SATB2-AS1 could sponge miR-155-3p, and BRMS1L was the target gene of miR-155-3p.

Conclusion

Elevated SATB2-AS1 and inhibited miR-155-3p could suppress the malignant phenotypes of BC cells, thereby restricting the development of BC.

Function and regulation of F-box/WD repeat-containing protein 7

The ubiquitin-proteasome system is an important post-translational modification system involved in numerous biological processes, such as cell cycle regulation, gene transcription, signal transduction, apoptosis, differentiation and development. F-box/WD repeat-containing protein 7 (FBXW7) is one of the most studied F-box (FBX) proteins, serving as substrate recognition component of S phase kinase-associated protein 1-Cullin 1-FBX protein complexes. As a tumor suppressor, FBXW7 recognizes numerous proto-oncoproteins and promotes their ubiquitination and subsequent proteasomal degradation. FBXW7 is regulated at different levels, leading to tunable and specific control of the activity and abundance of its substrates. Therefore, genetic mutations or decreases in its expression serve an important biological role in tumor development. In-depth studies and identification of additional substrates targeted by FBXW7 have suggested a signaling network regulated by FBXW7, including its tumor-inhibitory role. The present review focused on the role of FBXW7 in tumor suppression and its application in cancer therapy.

MiR-155 and MiR-665 Role as Potential Non-invasive Biomarkers for Hepatocellular Carcinoma in Egyptian Patients with Chronic Hepatitis C Virus Infection

Background and Objectives

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer associated death globally. Serum micro RNAs are full of potential as noninvasive biomarkers. Here, we aim to assess the performance of serum MicroRNA-155 and MicroRNA-665 as diagnostic biomarker for HCC comparing to AFP.

Methods

Serum samples were collected from 200 subjects (40 healthy control, 80 chronic hepatitis C patients with cirrhosis and without HCC (LC) and 80 HCC patients currently infected by hepatitis C infection and didn’t start the treatment). The HCC patients didn’t include alcoholic liver disease, nonalcoholic fatty liver disease nor autoimmune liver disease. MicroRNA-155 and MicroRNA-665 expression were measured by real-time quantitative PCR (RT-qPCR), while AFP level was assessed by ELISA method.

Results

Both miR-155 and miR-665 were significantly elevated in HCC group as compared to both control and LC groups. The comparison between LC and HCC patients revealed that the serum level of miR-155 was a significant increase in HCC patients compared to LC patients; however, the serum level of miR-665 didn’t show any significant difference between the same two groups. MiR-665 expression level showed a direct correlation with tumor size in HCC patients.

Conclusions

Using measurement against AFP level in serum, miR-665 is considered a promising serum biomarker for the diagnosis of HCC patients among the LC patients without HCC. MiR-155 didn’t provide a better performance than serum AFP as a diagnostic biomarker among the same group. MiR-665 may serve as a good indicator for HCC prognosis.

MiR-27a-3p Regulated the Aggressive Phenotypes of Cervical Cancer by Targeting FBXW7

Background

Abnormally expressed microRNAs (miRNAs) contribute greatly to the initiation and development of human cancers, including cervical cancer, by regulating the target mRNAs. MiR-27a-3p was up-regulated and acted as an oncogene in multiple cancers. However, the function of miR-27a-3p in cervical cancer has not been fully understood.

Methods

The expression of miR-27a-3p in cervical cancer tissues and cell lines was detected by RT-pPCR. MTT assay, colony formation assay and flow cytometry analysis were performed to determine the effects of miR-27a-3p on the growth of cervical cancer cells. The targets of miR-27a-3p were predicted using the miRDB database. Luciferase reporter assay was utilized to confirm the binding between miR-27a-3p and the 3ʹ-untranslated region (UTR) of targets. The expression of target proteins was determined by RT-qPCR and Western blot.

Results

Our results found that miR-27a-3p was overexpressed in cervical cancer tissues and cell lines. Down-regulation of miR-27a-3p significantly inhibited the proliferation, colony formation and promoted apoptosis of cervical cancer cells. Overexpression of miR-27a-3p enhanced the cell proliferation. miR-27a-3p was found to bind the 3ʹ-UTR of F-box and WD repeat domain containing 7 (FBXW7) and resulted in the down-regulation of FBXW7. The up-regulated level of miR-27a-3p was inversely correlated with that of FBXW7 in cervical cancer tissues. Additionally, reintroducing of FBXW7 significantly attenuated the promoting effect of miR-27a-3p on the proliferation of cervical cancer cells.

Conclusion

These results indicated the growth-promoting function of miR-27a-3p in cervical cancer via targeting FBXW7. Our finding suggested the potential application of miR-27a-3p/FBXW7 axis in the diagnosis and treatment of cervical cancer.

Recent insight into the role of FBXW7 as a tumor suppressor

FBXW7 (also known as Fbw7, Sel10, hCDC4, or hAgo) is a tumor suppressor and the most frequently mutated member of the F-box protein family in human cancers. FBXW7 functions as the substrate recognition component of an SCF-type E3 ubiquitin ligase. It specifically controls the proteasome-mediated degradation of many oncoproteins such as c-MYC, NOTCH, KLF5, cyclin E, c-JUN, and MCL1. In this review, we summarize the molecular and biological features of FBXW7 and its substrates as well as the impact of mutations of FBXW7 on cancer development. We also address the clinical potential of anticancer therapy targeting FBXW7.

LncRNA PCAT1 promotes metastasis of endometrial carcinoma through epigenetical downregulation of E-cadherin associated with methyltransferase EZH2

More than 140 thousands of women suffer from endometrial carcinoma in the worldwide, and over 40 thousand of the patients die before and after in surgery and chemoradiotherapy because of its metastasis. However, its molecular mechanism is much less known compared to other cancers. In this study, we demonstrated that long non-coding RNA PCAT1 is dramatically increased in the tissues and plasma from endometrial carcinoma (EC) (n = 100, all p < 0.001) controlled by its paracancerous tissue, and cell lines including RL-952, HEC-1-B, KLE, Ishikawa, and AN3CA compared to the cells from normal endometrium (all p < 0.001). When lncRNA PCAT1 was knocked-down, the KLE and AN3CA cells exhibited slow capability on proliferation and colony formation in vitro. With the silence of lncRNA PCAT1, the cells were markedly inhibited on migration and invasion in vitro (all p < 0.001), which were confirmed on the EC patient subjects. When expressions of lncRNA PCAT1 were interfered in the cells, expressions of E-cadherin but not N-cadherin and Vimentin were significantly promoted with a strong up-regulation accompanied by nearly completed recoveries on migration and invasion (all p < 0.001). In order to analyze the association of lncRNA PCAT1 and E-cadherin, we silenced the expressions of both genes and unveiled that EC migration and invasion were significantly congested (all p < 0.001). Importantly, we found that the E-cadherin down-regulation caused by lncRNA PCAT1 associates with histone methyltransferase EZH2. When over-expression of EZH2 was applied in the PCAT1 silenced cells, the expression of E-cadherin experienced significant decrease in the cell lines. Reversely, when expression of EZH2 was annulled in the PCAT1 silenced cells, the expression of E-cadherin was significantly boosted in the cells (all p < 0.001). Furthermore, the interaction of lncRNA PCAT1 and EZH2 were approved with immunoprecipitation. Our data demonstrated that the methyltransferase EZH2 related up-regulation of lncRNA PCAT1 along with down-regulation of E-cadherin could be essential in oncogenesis of endometrial carcinoma in both EC cells and patient subjects. These compact data suggest that combination of lncRNA PCAT1, EZH2 and E-cadherin could provide valued information for efficient EC diagnostics, which would propose a potential target for EC treatment with EZH2i on methyltransferation.

Targeting SCF E3 Ligases for Cancer Therapies

SKP1-cullin-1-F-box-protein (SCF) E3 ubiquitin ligase complex is responsible for the degradation of proteins in a strictly regulated manner, through which it exerts pivotal roles in regulating various key cellular processes including cell cycle and division, apoptosis, and differentiation. The substrate specificity of the SCF complex largely depends on the distinct F-box proteins, which function in either tumor promotion or suppression or in a context-dependent manner. Among the 69 F-box proteins identified in human genome, FBW7, SKP2, and β-TRCP have been extensively investigated among various types of cancer in respective of their roles in cancer development, progression, and metastasis. Moreover, several specific inhibitors have been developed to target those E3 ligases, and their efficiency in tumors has been determined. In this review, we provide a summary of the roles of SCF E3 ligases in cancer development, as well as the potential application of miRNA or specific inhibitors for cancer therapy.

Knockdown of miR-106a suppresses migration and invasion and enhances radiosensitivity of hepatocellular carcinoma cells by upregulating FBXW7

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. microRNAs (miRNAs) have been reported to play essential roles in HCC progression and radiosensitivity. However, the effect of miR-106a on HCC progression and radiosensitivity as well as its mechanism remain largely unknown. The expressions of miR-106a and F-box and WD repeat domain containing 7 (FBXW7) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot, respectively. Cell migration and invasion were analyzed by trans-well assay. The radiosensitivity was investigated by colony formation and western blot. The interaction between miR-106a and FBXW7 was explored by luciferase activity and RNA immunoprecipitation (RIP) analyses. Then miR-106a expression was elevated in HCC tissues and cells and associated with tumor stage as well as overall survival. Knockdown of miR-106a impeded cell migration and invasion but contributed to irradiation-induced inhibition of survival and increase of phosphorylation of histone in Serine 139 (γ-H2AX) protein in HCC cells. Moreover, FBXW7 was indicated as a target of miR-106a and negatively correlated with miR-106a. Besides, interference of FBXW7 reversed the regulatory effect of miR-106a abrogation on migration, invasion and radiosensitivity in HCC cells. The results showed down-regulation of miR-106a suppressed migration and invasion and increased radiosensitivity of HCC cells by targeting FBXW7, providing a novel avenue for HCC treatment.

Repression of lncRNA NEAT1 enhances the antitumor activity of CD8+T cells against hepatocellular carcinoma via regulating miR-155/Tim-3

BACKGROUND

Immunotherapy is a promising method for the treatment of hepatocellular carcinoma (HCC), in which CD8⁺T cells play a key role. The influence of long noncoding RNA (lncRNA) nuclear-enriched autosomal transcript 1(NEAT1) on the antitumor activity of CD8⁺T cells was clarified in this study.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from HCC patients, and the expressions of NEAT1 and Tim-3 were determined by qRT-PCR and western blot, respectively. CD8⁺T cell apoptosis and cell percentage were analyzed via flow cytometry. The cytolysis activity of CD8⁺T cells against HCC cells was examined. RNA immunoprecipitation (RIP) and RNA pull-down assay were performed to explore the interaction between NEAT1 and miR-155.

RESULTS

NEAT1 and Tim-3 were up-regulated in the PBMCs of patients with HCC (n = 20) compared with healthy subjects (n = 20). Down-regulation of NEAT1 restrained CD8⁺T cell apoptosis and enhanced the cytolysis activity, while interference of miR-155 showed the opposite effects by up-regulating Tim-3. Binding and interaction between NEAT1 and miR-155 were validated in CD8⁺T cells. Down-regulation of NEAT1 restrained CD8⁺T cell apoptosis and enhanced the cytolysis activity through the miR-155/Tim-3 pathway. Repression of NEAT1 suppressed tumor growth in HCC mice.

CONCLUSION

Via modulating the miR-155/Tim-3 pathway, repression of NEAT1 restrained CD8⁺T cell apoptosis and enhanced the cytolysis activity against HCC, implying an effective target for improving the outcome of immunotherapy.

Columbamine suppresses hepatocellular carcinoma cells through down-regulation of PI3K/AKT, p38 and ERK1/2 MAPK signaling pathways

Hepatocellular carcinoma (HCC) as primary liver cancer in adults is the most common cause led to internal cirrhosis responsible for patients' death, which resulted in nearly a million deaths worldwide on both males and females in the developing and developed countries. Unfortunately, up to date, there are no highly effective treatment of medicine on HCC as lack of comprehensive cellular and molecular mechanism. According to the sources of human ancient history of medicine, traditional medicine could provide unique treatment to discontinue the challenging HCC. In this study, we inspected the effect of Columbamine (Col; C20H21NO5), an alkaloid isolated from calumba, on HCC utilizing three HCC cell-lines i.e. SMMC7721, HepG2 and Hep3B. Our data collected from these cell-lines exhibit strong Col suppression on the cell growth accompanying the dosage-dependent suppression, and we further confirmed the suppression on the tumor-growth in animal model. Rational of the Col suppression presents cellular mechanism by limiting the proliferation and colony formation of the cells marked with decreased expression of PCNA. Meanwhile decreases of migration indicated with increasing expression of E-cadherin and decreasing expression of N-cadherin, and of invasion labelled with decreasing expressions of MMP2 and MMP9, are accompanying the Col suppression along with the Col promoted apoptosis of the tumor cells. This programmed cell death marketed with cleaved Caspase 3 plus PAPR proteins, up-regulation of BAD and down-regulation of BCL2 is linked the Col suppression to unique calcium-related pathways. Our results unveiled that the Columbamine suppression on HCC based on the traditional medicine are clearly associated with PI3K/AKT, p38 and ERK1/2 MAPKs signaling pathways and guide further research orientation for developing the Col medicine against hepatocellular carcinoma.

microRNAs: Key players in virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as one of the major health problems worldwide. Pathological analysis indicated that a variety of risk factors including genetical (i.e., alteration of tumor suppressors and oncogenes) and environmental factors (i.e., viruses) are involved in beginning and development of HCC. The understanding of these risk factors could guide scientists and clinicians to design effective therapeutic options in HCC treatment. Various viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) via targeting several cellular and molecular pathways involved in HCC pathogenesis. Among various cellular and molecular targets, microRNAs (miRNAs) have appeared as key players in HCC progression. miRNAs are short noncoding RNAs which could play important roles as oncogenes or tumor suppressors in several malignancies such as HCC. Deregulation of many miRNAs (i.e., miR-222, miR-25, miR-92a, miR-1, let-7f, and miR-21) could be associated with different stages of HCC. Besides miRNAs, exosomes are other particles which are involved in HCC pathogenesis via targeting different cargos, such as DNAs, RNAs, miRNAs, and proteins. In this review, we summarize the current knowledge of the role of miRNAs and exosomes as important players in HCC pathogenesis. Moreover, we highlighted HCV- and HBV-related miRNAs which led to HCC progression.

FBXW7: a critical tumor suppressor of human cancers

The ubiquitin-proteasome system (UPS) is involved in multiple aspects of cellular processes, such as cell cycle progression, cellular differentiation, and survival (Davis RJ et al., Cancer Cell 26:455-64, 2014; Skaar JR et al., Nat Rev Drug Discov 13:889-903, 2014; Nakayama KI and Nakayama K, Nat Rev Cancer 6:369-81, 2006). F-box and WD repeat domain containing 7 (FBXW7), also known as Sel10, hCDC4 or hAgo, is a member of the F-box protein family, which functions as the substrate recognition component of the SCF E3 ubiquitin ligase. FBXW7 is a critical tumor suppressor and one of the most commonly deregulated ubiquitin-proteasome system proteins in human cancer. FBXW7 controls proteasome-mediated degradation of oncoproteins such as cyclin E, c-Myc, Mcl-1, mTOR, Jun, Notch and AURKA. Consistent with the tumor suppressor role of FBXW7, it is located at chromosome 4q32, a genomic region deleted in more than 30% of all human cancers (Spruck CH et al., Cancer Res 62:4535-9, 2002). Genetic profiles of human cancers based on high-throughput sequencing have revealed that FBXW7 is frequently mutated in human cancers. In addition to genetic mutations, other mechanisms involving microRNA, long non-coding RNA, and specific oncogenic signaling pathways can inactivate FBXW7 functions in cancer cells. In the following sections, we will discuss the regulation of FBXW7, its role in oncogenesis, and the clinical implications and prognostic value of loss of function of FBXW7 in human cancers.

NT21MP negatively regulates paclitaxel-resistant cells by targeting miR‑155‑3p and miR‑155-5p via the CXCR4 pathway in breast cancer

Evidence has shown that microRNAs (miRNAs) are vital in cell growth, migration, and invasion by inhibiting their target genes. A previous study demonstrated that miRNA (miR)-155-3p and miR-155-5p exerted opposite effects on cell proliferation, apoptosis, migration and invasion in breast cancer cell lines. An miRNA microarray was used to show that miR-155-3p was downregulated whereas miR-155-5p was upregulated in paclitaxel-resistant (PR) cells compared with parental breast cancer cells. However, the role of miR-155 in breast cancer cell invasion and metastasis remains to be elucidated. A 21-residue peptide derived from the viral macrophage inflammatory protein II (NT21MP), competes with the ligand of CXC chemokine receptor 4 (CXCR4) and its ligand stromal cell-derived factor-1α, inducing cell apoptosis in breast cancer. The present study aimed to identify the underlying mechanism of action of miR-155-3p/5p and NT21MP in PR breast cancer cells. Quantitative polymerase chain reaction, western blotting, wound-healing, cell cycle and apoptosis assays, and Cell Counting kit-8 assay were used to achieve this goal. The combined overexpression of miR-155-3p with NT21MP decreased the migration and invasion ability and increased the number of apoptotic and arrested cells in the G0/G1 phase transition in vitro. The knockdown of miR-155-5p combined with NT21MP had a similar effect on PR breast cancer cells. Furthermore, the ectopic expression of their target gene myeloid differentiation primary response gene 88 (MYD88) or tumor protein 53-induced nuclear protein 1 (TP53INP1) combined with NT21MP enhanced the sensitivity of the breast cancer cells to paclitaxel. Taken together, these findings suggested that miR-155-3p/5p and their target genes MYD88 and TP53INP1 may serve as novel biomarkers for NT21MP therapy through the CXCR4 pathway for improving sensitivity to paclitaxel in breast cancer.

MiR-182 promotes cell proliferation by suppressing FBXW7 and FBXW11 in non-small cell lung cancer

OBJECTIVE

MicroRNAs have been found to be deregulated in lung cancers, which play crucial roles in tumorigenesis and progression. FBXW7 and FBXW11, two important F-box proteins of the ubiquitin-proteasome system (UPS), can target multiple substrates for degradation, in order to regulate cell proliferation and survival in cancers. In the present study, we aimed to explore the potential role and regulating mechanism of miR-182 in non-small cell lung cancer (NSCLC).

METHODS

MiRNA expression was evaluated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). FBXW7, FBXW11, c-Jun, c-Myc and cyclin D protein levels were detected by western blot. Cell growth was determined using cell counting kit (CCK)-8 reagent and colony formation experiment. Then, cell apoptosis and the cell cycle were analyzed on flow cytometry. The target binding activity of miR-182 with FBXW7 or FBXW11 was evaluated through the Dual-Luciferase Reporter Assay System.

RESULTS

It was confirmed that miR-182 was significantly upregulated in tumor tissues, compared with adjacent normal tissues, and this was inversely correlated to the protein levels of FBXW7 and FBXW11. The overexpression of miR-182 in NSCLC cells dramatically promoted cell growth, colony formation capacity and cell cycle progression, and inhibited apoptosis in NSCLC cells. In contrast, the downregulation of miR-182 significantly alleviated these properties in vitro. Furthermore, we demonstrated that miR-182 exerted an oncogenic role in NSCLC by directly targeting FBXW7 and FBXW11.

CONCLUSION

These results bring new insights into the oncogenic role of miR-182 in NSCLC, indicating that miR-182 might be a novel biomarker for the diagnosis and prognosis of NSCLC.

MicroRNA31-NDRG3 regulation axes are essential for hepatocellular carcinoma survival and drug resistance

BACKGROUNDS

Hepatocellular carcinoma (HCC) is an epithelial cancer that originates from hepatocytes and it is the most common primary malignant tumor of the liver. Till now the prognosis of HCC patients is generally poor. The molecular mechanism giving rise to HCC development and recurrence is still largely unknown. MicroRNA-31 (miR-31) is among the most commonly altered microRNAs in human cancers, and alternations of miR-31 expression were reported to play pivotal roles in tumorigenesis and tumor progression.

METHODS

In this work, the primary biological function of miR-31 in HCC tumorigenesis was investigated.

RESULTS

Our data showed that overexpression of miR-31 induced markedly inhibition of HCC cell proliferation, migration in vitro and inhibited xenograft tumor growth in vivo. One target gene of miR-31, NDRG3, was also demonstrated indispensable for HCC cell survival. Furthermore, miR-31 and NDRG3 were both essential for HCC cell drug resistance in adriamycin.

CONCLUSIONS

We conclude that miR-31 is a crucial regulator in hepatocellular carcinoma, miR-31 and its target gene NDRG3 may be potential therapeutic targets for HCC treatment in the future.

Prognostic value of microRNAs in hepatocellular carcinoma: a meta-analysis

Background

Numerous articles reported that dysregulated expression levels of miRNAs correlated with survival time of HCC patients. However, there has not been a comprehensive meta-analysis to evaluate the accurate prognostic value of miRNAs in HCC.

Design

Meta-analysis.

Materials and Methods

Studies, published in English, estimating expression levels of miRNAs with any survival curves in HCC were identified up until 15 April, 2017 by performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two independent authors. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

Results

54 relevant articles about 16 miRNAs, with 6464 patients, were ultimately included. HCC patients with high expression of tissue miR-9 (HR = 2.35, 95% CI = 1.46–3.76), miR-21 (HR = 1.76, 95% CI = 1.29–2.41), miR-34c (HR = 1.64, 95% CI = 1.05–2.57), miR-155 (HR = 2.84, 95% CI = 1.46–5.51), miR-221 (HR = 1.76, 95% CI = 1.02–3.04) or low expression of tissue miR-22 (HR = 2.29, 95% CI = 1.63–3.21), miR-29c (HR = 1.35, 95% CI = 1.10–1.65), miR-34a (HR = 1.84, 95% CI = 1.30–2.59), miR-199a (HR = 2.78, 95% CI = 1.89–4.08), miR-200a (HR = 2.64, 95% CI = 1.86–3.77), miR-203 (HR = 2.20, 95% CI = 1.61–3.00) have significantly poor OS (P < 0.05). Likewise, HCC patients with high expression of blood miR-21 (HR = 1.73, 95% CI = 1.07–2.80), miR-192 (HR = 2.42, 95% CI = 1.15–5.10), miR-224 (HR = 1.56, 95% CI = 1.14–2.12) or low expression of blood miR-148a (HR = 2.26, 95% CI = 1.11–4.59) have significantly short OS (P < 0.05).

Conclusions

In conclusion, tissue miR-9, miR-21, miR-22, miR-29c, miR-34a, miR-34c, miR-155, miR-199a, miR-200a, miR-203, miR-221 and blood miR-21, miR-148a, miR-192, miR-224 demonstrate significantly prognostic value. Among them, tissue miR-9, miR-22, miR-155, miR-199a, miR-200a, miR-203 and blood miR-148a, miR-192 are potential prognostic candidates for predicting OS in HCC.

WITHDRAWN: Epigenetics in Chronic Liver Disease

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The short and the long: non-coding RNAs and growth factors in cancer progression

A relatively well-understood multistep process enables mutation-bearing cells to form primary tumours, which later use the circulation system to colonize new locations and form metastases. However, in which way the emerging abundance of different non-coding RNAs supports tumour progression is poorly understood. Here, we review new lines of evidence linking long and short types of non-coding RNAs to signalling pathways activated in the course of cancer progression by growth factors and by the tumour micro-environment. Resolving the new dimension of non-coding RNAs in oncogenesis will probably translate to earlier detection of cancer and improved therapeutic strategies.

The overexpression of Rabl3 is associated with pathogenesis and clinicopathologic variables in hepatocellular carcinoma

Overexpression of Rabl3 is associated with some malignancies. However, their relationship with hepatocellular carcinoma remains unclear. In this study, the expression of Rabl3 in hepatocellular carcinoma cell lines, and four pairs of matched hepatocellular carcinoma tissues and their adjacent normal hepatic tissues were detected by quantitative reverse transcription polymerase chain reaction and western blot. In addition, the protein expression of Rabl3 was examined in 162 cases of hepatocellular carcinoma by immunohistochemistry. Rabl3 in hepatocellular carcinoma cell lines was elevated at both messenger RNA and protein levels, and the Rabl3 protein was significantly upregulated by upto 3.3-fold in hepatocellular carcinoma compared with the paired normal hepatic tissues. Immunohistochemical analysis revealed that overexpressions of Rabl3 were 80.2% in hepatocellular carcinoma. Rabl3 is expressed at significantly higher rates in hepatocellular carcinoma compared with adjacent normal hepatic tissue (p < 0.01). Statistical analysis suggested the upregulation of Rabl3 was significantly associated with lymph node metastasis, tumor thrombus of the portal vein, and advanced clinical stage (p < 0.05). Furthermore, we found that overexpression of Rabl3 in hepatocellular carcinoma cells could significantly enhance cell proliferation and growth ability. Conversely, silencing Rabl3 by small hairpin RNA interference caused an inhibition of cell proliferation and growth. Our studies suggest that the Rabl3 is a valuable marker of hepatocellular carcinoma progression and that the overexpression of Rabl3 plays an important role in the development and pathogenesis of hepatocellular carcinoma.

MiR-221 mediates the epithelial-mesenchymal transition of hepatocellular carcinoma by targeting AdipoR1

Recent studies have shown that miRNAs play vital roles in tumorigenesis. However, their effects on the epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) need to be better understood. Our present study demonstrates that miR-221, which is overexpressed in HCC tissues, promotes EMT in HCC cell lines by targeting a new gene, AdipoR1. First, overexpression of miR-221 was identified in 40 pairs of human HCC tumor and matched normal tissues. Moreover, we found that elevated miR-221 was strongly associated with worse clinicopathologic features in HCC patients. Next, the loss of miR-221 inhibited, but its restoration enhanced, the EMT process in HCC cell lines. Furthermore, bioinformatics software predicted that AdipoR1 would be a direct target of miR-221. We then observed negative regulation of miR-221 on AdipoR1 protein expression, and direct binding between them was further verified using dual-luciferase assays. In addition, knockdown of AdipoR1 resulted in promotion of the EMT in HCC cells, and AdipoR1 overexpression reversed the miR-221-induced EMT. Lastly, we found that the JAK/STAT3 pathway may be involved in the AdipoR1-mediated EMT process. In conclusion, miR-221 acts as a promoter of the EMT process in HCC cells by targeting AdipoR1, and this study highlights the potential effects of miR-221 on the prognosis and treatment of HCC.

New Insights into the Epigenetics of Hepatocellular Carcinoma

Hepatocellular Carcinoma (HCC) is one of the most predominant malignancies with high fatality rate. This deadly cancer is rising at an alarming rate because it is quite resistant to radio- and chemotherapy. Different epigenetic mechanisms such as histone modifications, DNA methylation, chromatin remodeling, and expression of noncoding RNAs drive the cell proliferation, invasion, metastasis, initiation, progression, and development of HCC. These epigenetic alterations because of potential reversibility open way towards the development of biomarkers and therapeutics. The contribution of these epigenetic changes to HCC development has not been thoroughly explored yet. Further research on HCC epigenetics is necessary to better understand novel molecular-targeted HCC treatment and prevention. This review highlights latest research progress and current updates regarding epigenetics of HCC, biomarker discovery, and future preventive and therapeutic strategies to combat the increasing risk of HCC.

Targeting MicroRNAs in Cancer Gene Therapy

MicroRNAs (miRNAs) are a kind of conserved small non-coding RNAs that participate in regulating gene expression by targeting multiple molecules. Early studies have shown that the expression of miRNAs changes significantly in different tumor tissues and cancer cell lines. It is well acknowledged that such variation is involved in almost all biological processes, including cell proliferation, mobility, survival and differentiation. Increasing experimental data indicate that miRNA dysregulation is a biomarker of several pathological conditions including cancer, and that miRNA can exert a causal role, as oncogenes or tumor suppressor genes, in different steps of the tumorigenic process. Anticancer therapies based on miRNAs are currently being developed with a goal to improve outcomes of cancer treatment. In our present study, we review the function of miRNAs in tumorigenesis and development, and discuss the latest clinical applications and strategies of therapy targeting miRNAs in cancer.