Neurotensin signaling activates microRNAs-21 and -155 and Akt, promotes tumor growth in mice, and is increased in human colon tumors

Exosomes Derived from hucMSCs Primed with IFN-γ Suppress the NF-κB Signal Pathway in LPS-Induced ALI by Modulating the miR-199b-5p/AFTPH Axis

Exosomes (exos) are primarily responsible for the process of mesenchymal stem cells (MSCs) treatment for acute lung injury (ALI), but the mechanism remains unclear, particularly in altered microenvironment. Therefore, this study aimed to investigate the potential mechanism of exos derived from human umbilical cord mesenchymal stem cells (hucMSCs) primed with interferon-gamma (IFN-γ) on ALI and to propose a promising and cell-free strategy. This study extracted exos from hucMSCs supernatant primed and unprimed with IFN-γ marked with IFN-γ-exos and CON-exos, which were identified and traced. IFN-γ-exos administration to ALI models suppressed the NF-κB signaling pathway compared to CON-exos, which were quantified through western blot and immunohistochemical staining. Reverse transcription-quantitative polymerase chain reaction validated miR-199b-5p expression in the IFN-γ-exos and CON-exos treatment groups. Data analysis, a dual-luciferase reporter assay, and cell transfection were conducted to investigate the target binding between miR-199b-5p and Aftiphilin (AFTPH), with AFTPH expression analyzed via cell immunofluorescence and western blot. Co-immunoprecipitation was conducted for the interaction between AFTPH and NF-κB p65. The result revealed that miR-199b-5p was down-regulated in the IFN-γ-exos treatment group, which had a target binding site with AFTPH, and an interaction with NF-κB p65. Consequently, IFN-γ-exos inhibited the NF-κB signaling pathway in ALI in vitro and in vivo through the miR-199b-5p/AFTPH axis. Our results demonstrated new directions of novel and targeted treatment for ALI.

Unlocking the Potential of Extracellular Vesicles as the Next Generation Therapy: Challenges and Opportunities

BACKGROUND

Mesenchymal stem cells (MSCs) have undergone extensive investigation for their potential therapeutic applications, primarily attributed to their paracrine activity. Recently, researchers have been exploring the therapeutic potential of extracellular vesicles (EVs) released by MSCs.

METHODS

MEDLINE/PubMed and Google scholar databases were used for the selection of literature. The keywords used were mesenchymal stem cells, extracellular vesicles, clinical application of EVs and challenges EVs production.

RESULTS

These EVs have demonstrated robust capabilities in transporting intracellular cargo, playing a critical role in facilitating cell-to-cell communication by carrying functional molecules, including proteins, RNA species, DNAs, and lipids. Utilizing EVs as an alternative to stem cells offers several benefits, such as improved safety, reduced immunogenicity, and the ability to traverse biological barriers. Consequently, EVs have emerged as an increasingly attractive option for clinical use.

CONCLUSION

From this perspective, this review delves into the advantages and challenges associated with employing MSC-EVs in clinical settings, with a specific focus on their potential in treating conditions like lung diseases, cancer, and autoimmune disorders.

microRNAs, oxidative stress, and genotoxicity as the main inducers in the pathobiology of cancer development

Cancer is one of the most serious leading causes of death in the world. Many eclectic factors are involved in cancer progression including genetic and epigenetic alongside environmental ones. In this account, the performance and fluctuations of microRNAs are significant in cancer diagnosis and treatment, particularly as diagnostic biomarkers in oncology. So, microRNAs manage and control the gene expression after transcription by mRNA degradation, or also they can inhibit their translation. Conspicuously, these molecular structures take part in controlling the cellular, physiological and pathological functions, which many of them can accomplish as tumor inhibitors or oncogenes. Relatively, Oxidative stress is defined as the inequality between the creation of reactive oxygen species (ROS) and the body's ability to detoxify the reactive mediators or repair the resulting injury. ROS and microRNAs have been recognized as main cancer promoters and possible treatment targets. Importantly, genotoxicity has been established as the primary reason for many diseases as well as several malignancies. The procedures have no obvious link with mutagenicity and influence the organization, accuracy of the information, or fragmentation of DNA. Conclusively, mutations in these patterns can lead to carcinogenesis. In this review article, we report the impressive and practical roles of microRNAs, oxidative stress, and genotoxicity in the pathobiology of cancer development in conjunction with their importance as reliable cancer biomarkers and their association with circulating miRNA, exosomes and exosomal miRNAs, RNA remodeling, DNA methylation, and other molecular elements in oncology.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

Can Dietary Actives Affect miRNAs and Alter the Course or Prevent Colorectal Cancer?

Colorectal cancer is a diet-related cancer. There is much research into the effects of nutrients on the prevention, modulation, and treatment of colorectal cancer. Researchers are trying to find a correlation between epidemiological observations indicating certain dietary components as the originator in the process of developing colorectal cancer, such as a diet rich in saturated animal fats, and dietary components that could eliminate the impact of harmful elements of the daily nutritional routine, i.e., substances such as polyunsaturated fatty acids, curcumin, or resveratrol. Nevertheless, it is very important to understand the mechanisms underlying how food works on cancer cells. In this case, microRNA (miRNA) seems to be a very significant research target. MiRNAs participate in many biological processes connected to carcinogenesis, progression, and metastasis. However, this is a field with development prospects ahead. In this paper, we review the most significant and well-studied food ingredients and their effects on various miRNAs involved in colorectal cancer.

Role of MicroRNAs in Regulation of Cellular Response to Hypoxia

Hypoxia causes changes in transcription of the genes that contribute to adaptation of the cells to low levels of oxygen. The main mechanism regulating cellular response to hypoxia is activation of hypoxia-inducible transcription factors (HIF), which include several isoforms and control expression of more than a thousand genes. HIF activity is regulated at various levels, including by small non-coding RNA molecules called microRNAs (miRNAs). miRNAs regulate cellular response to hypoxia by influencing activation of HIF, its degradation, and translation of HIF-dependent proteins. At the same time, HIFs also affect miRNAs biogenesis. Data on the relationship of a particular HIF isoform with miRNAs are contradictory, since studies have been performed using different cell lines, various types of experimental animals and clinical material, as well as at different oxygen concentrations and durations of hypoxic exposure. In addition, HIF expression may be affected by the initial resistance of organisms to lack of oxygen, which has not been taken into account in the studies. This review analyzes the data on the effect of hypoxia on biogenesis and functioning of miRNAs, as well as on the effect of miRNAs on mRNAs of the genes involved in adaptation to oxygen deficiency. Understanding the mechanisms of relationship between HIF, hypoxia, and miRNA is necessary to develop new approaches to personalized therapy for diseases accompanied by oxygen deficiency.

HypoxaMIRs: Key Regulators of Hallmarks of Colorectal Cancer

Hypoxia in cancer is a thoroughly studied phenomenon, and the logical cause of the reduction in oxygen tension is tumor growth itself. While sustained hypoxia leads to death by necrosis in cells, there is an exquisitely regulated mechanism that rescues hypoxic cells from their fatal fate. The accumulation in the cytoplasm of the transcription factor HIF-1α, which, under normoxic conditions, is marked for degradation by a group of oxygen-sensing proteins known as prolyl hydroxylases (PHDs) in association with the von Hippel-Lindau anti-oncogene (VHL) is critical for the cell, as it regulates different mechanisms through the genes it induces. A group of microRNAs whose expression is regulated by HIF, collectively called hypoxaMIRs, have been recognized. In this review, we deal with the hypoxaMIRs that have been shown to be expressed in colorectal cancer. Subsequently, using data mining, we analyze a panel of hypoxaMIRs expressed in both normal and tumor tissues obtained from TCGA. Finally, we assess the impact of these hypoxaMIRs on cancer hallmarks through their target genes.

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.

MicroRNAs Are Key Molecules Involved in the Gene Regulation Network of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common types of cancer and one of the leading causes of mortality worldwide. MicroRNAs (miRNAs) play central roles in normal cell maintenance, development, and other physiological processes. Growing evidence has illustrated that dysregulated miRNAs can participate in the initiation, progression, metastasis, and therapeutic resistance that confer miRNAs to serve as clinical biomarkers and therapeutic targets for CRC. Through binding to the 3′-untranslated region (3′-UTR) of target genes, miRNAs can lead to target mRNA degradation or inhibition at a post-transcriptional level. During the last decade, studies have found numerous miRNAs and their potential targets, but the complex network of miRNA/Targets in CRC remains unclear. In this review, we sought to summarize the complicated roles of the miRNA-target regulation network (Wnt, TGF-β, PI3K-AKT, MAPK, and EMT related pathways) in CRC with up-to-date, high-quality published data. In particular, we aimed to discuss the downstream miRNAs of specific pathways. We hope these data can be a potent supplement for the canonical miRNA-target regulation network.

Intelligent Gold Nanoparticles with Oncogenic MicroRNA-Dependent Activities to Manipulate Tumorigenic Environments for Synergistic Tumor Therapy

Tumorigenic environments, especially aberrantly overexpressed oncogenic microRNAs, play a critical role in various activities of tumor progression. However, developing strategies to effectively utilize and manipulate these oncogenic microRNAs for tumor therapy is still a challenge. To address this challenge, spherical nucleic acids (SNAs) consisting of gold nanoparticles in the core and antisense oligonucleotides as the shell are fabricated. Hybridized to the oligonucleotide shell is a DNA sequence to which doxorubicin is conjugated (DNA-DOX). The oligonucleotides shell is designed to capture overexpressed miR-21/miR-155 and inhibit the expression of these oncogenic miRNAs in tumor cells after tumor accumulation to manipulate genetic environment for accurate gene therapy. This process further induces the aggregation of these SNAs, which not only generates photothermal agents to achieve on-demand photothermal therapy in situ, but also enlarges the size of SNAs to enhance the retention time in the tumor for sustained therapy. The capture of the relevant miRNAs simultaneously triggers the intracellular release of the DNA-DOX from the SNAs to deliver tumor-specific chemotherapy. Both in vivo and in vitro results indicate that this combination strategy has excellent tumor inhibition properties with high survival rate of tumor-bearing mice, and can thus be a promising candidate for effective tumor treatment.

Role of microRNAs in response to cadmium chloride in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal and aggressive malignancies with a 5-year survival rate less than 9%. Early detection is particularly difficult due to the lack of symptoms even in advanced stages. microRNAs (miRs/miRNAs) are small (~ 18-24 nucleotides), endogenous, non-coding RNAs, which are involved in the pathogenesis of several malignancies including PDAC. Alterations of miR expressions can lead to apoptosis, angiogenesis, and metastasis. The role of environmental pollutants such as cadmium (Cd) in PDAC has been suggested but not fully understood. This study underlines the role of miRs (miR-221, miR-155, miR-126) in response to cadmium chloride (CdCl2) in vitro. Lethal concentration (LC50) values for CdCl2 resulted in a toxicity series of AsPC-1 > HPNE > BxPC-3 > Panc-1 = Panc-10.5. Following the treatment with CdCl2, miR-221 and miR-155 were significantly overexpressed, whereas miR-126 was downregulated. An increase in epithelial-mesenchymal transition (EMT) via the dysregulation of mesenchymal markers such as Wnt-11, E-cadherin, Snail, and Zeb1 was also observed. Hence, this study has provided evidence to suggest that the environmental pollutant Cd can have a significant role in the development of PDAC, suggesting a significant correlation between miRs and Cd exposure during PDAC progression. Further studies are needed to investigate the precise role of miRs in PDAC progression as well as the role of Cd and other environmental pollutants.

The miR-345-3p/PPP2CA signaling axis promotes proliferation and invasion of breast cancer cells

Breast cancer is the most common malignancy among women worldwide. Functional studies have demonstrated that miRNA dysregulation in many cases of cancer, in which miRNAs acting as either oncogenes or tumor suppressor. Here we report that miR-345-3p is generally upregulated in breast cancer tissues and breast cancer cell lines. Overexpression and inhibition of miR-345-3p revealed its capacity in regulating proliferation and invasion of breast cancer cells. Further research identified protein phosphatase 2 catalytic subunit alpha (PPP2CA), a suppressor of AKT phosphorylation, as a candidate target of miR-345-3p. In vitro, miR-345-3p mimics promoted AKT phosphorylation by targeting its negative regulator, PPP2CA. Blocking miR-345-3p relieves its inhibition of PPP2CA, which attenuated PI3K-AKT signaling pathway. In vivo, inhibiting miR-345-3p with miR-345-3p-inhibition lentivirus suppressed tumor growth and invasiveness in mice. Together, the miR-345-3p/PPP2CA signaling axis exhibits tumor promoting functions by regulating proliferation and invasion of breast cancer cells. These data provide a clue to novel therapeutic approaches for breast cancer.

The molecular mechanism of chronic stress affecting the occurrence and development of breast cancer and potential drug therapy

According to the 2020 data released by the International Agency for Research on Cancer, breast cancer has surpassed lung cancer as the world's most newly diagnosed first-time cancer. Compared with patients with other types of cancer, those with breast cancer experience greater mental stress and more severe psychological impacts because of the life-threatening diagnosis, physical changes, treatment side effects, and family and social life dysfunctions. These usually manifest as anxiety, depression, nervousness, and insomnia, all of which elicit stress responses. Particularly under chronic stress, the continuous release of neurotransmitters from the neuroendocrine system can have a highly profound impact on the occurrence and prognosis of breast cancer. However, because of the complex mechanisms underlying chronic stress and the variability in individual tolerance, evidence of the role of chronic stress in the occurrence and evolution of breast cancer remains unclear. This article reviewed previous research on the correlation between chronic stress and the occurrence and development of breast cancer, particularly the molecular mechanism through which chronic stress promotes breast cancer via neurotransmitters secreted by the nervous system. We also review the progress in the development of potential drugs or blockers for the treatment of breast cancer by targeting the neuroendocrine system.

The Neurotensinergic System: A Target for Cancer Treatment

BACKGROUND

The scientific interest regarding the involvement of peptides in cancer has increased in the last years. In tumor cells the overexpression of peptides and their receptors is known and new therapeutic targets for the treatment of cancer have been suggested. The overexpression of the neurotensinergic system has been associated with poor prognosis, tumor size, higher tumor aggressiveness, increased relapse risk and worse sensitivity to chemotherapy agents.

OBJECTIVE

The aim of this review is to update the findings regarding the involvement of the neurotensinergic system in cancer to suggest anticancer therapeutic strategies targeting this system. The neurotensin (NT) precursor, NT and its receptors (NTR) and the involvement of the neurotensinergic system in lung, breast, prostate, gastric, colon, liver and pancreatic cancers, glioblastoma, neuroendocrine tumors and B-cell leukemia will be mentioned and discussed as well as the signaling pathways mediated by NT. Some research lines to be developed in the future will be suggested such as: molecules regulating the expression of the NT precursor, influence of the diet in the development of tumors, molecules and signaling pathways activated by NT and antitumor therapeutic strategies targeting the neurotensinergic system.

CONCLUSION

NT, via the NTR, exerts oncogenic (tumor cell proliferation, invasion, migration, angiogenesis) and antiapoptotic effects, whereas NTR antagonists inhibit these effects. NTR expression can be used as a diagnostic tool/therapeutic target and the administration of NTR antagonists as antitumor drugs could be a therapeutic strategy to treat tumors overexpressing NTR.

The Role of microRNAs in Development of Colitis-Associated Colorectal Cancer

Colorectal cancer (CRC) is the third most deadly cancer worldwide, and inflammatory bowel disease (IBD) is one of the critical factors in CRC carcinogenesis. IBD is responsible for an unphysiological and sustained chronic inflammation environment favoring the transformation. MicroRNAs (miRNAs) belong to a class of highly conserved short single-stranded segments (18-25 nucleotides) non-coding RNA and have been extensively discussed in both CRC and IBD. However, the role of miRNAs in the development of colitis-associated CRC (CAC) is less clear. The aim of this review is to summarize the major upregulated (miR-18a, miR-19a, miR-21, miR-31, miR-155 and miR-214) and downregulated (miR-124, miR-193a-3p and miR-139-5p) miRNAs in CAC, and their roles in genes' expression modulation in chronic colonic-inflammation-induced carcinogenesis, including programmed cell-death pathways. These miRNAs dysregulation could be applied for early CAC diagnosis, to predict therapy efficacy and for precision treatment.

Dissecting miRNA signature in colorectal cancer progression and metastasis

Colorectal cancer (CRC) is the third most common cancer and leading cause of cancer related deaths worldwide. Despite recent advancements in surgical and molecular targeted therapies that improved the therapeutic efficacy in CRC, the 5 years survival rate of CRC patients still remains frustratingly poor. Accumulated evidences indicate that microRNAs (miRNAs) play a crucial role in the progression and metastasis of CRC. Dysregulated miRNAs are closely associated with cancerous phenotypes (e.g. enhanced proliferative and invasive ability, evasion of apoptosis, cell cycle aberration, and promotion of angiogenesis) by regulating their target genes. In this review, we provide an updated overview of tumor suppressive and oncogenic miRNAs, circulatory miRNAs, and the possible causes of dysregulated miRNAs in CRC. In addition, we discuss the important functions of miRNAs in drug resistance of CRC.

Expression profiles and prognostic significance of AFTPH in different tumors

Aftiphilin (AFTPH) plays an important role in regulating intracellular trafficking, exocytosis, and the pro‐inflammatory response. However, the potential prognostic role of AFTPH in cancers remains unclear. Here, we examined the expression profiles and prognostic significance of AFTPH in breast invasive carcinoma (BRCA), diffuse large B‐cell lymphoma (DLBC), lung squamous cell carcinoma (LUSC), and pancreatic adenocarcinoma (PADD) using the GEPIA and UALCAN databases. AFTPH expression was observed to be higher in cancer tissues than in normal tissues, but expression did not differ significantly between tumor stages for the four cancer types. AFTPH expression in cancer cell lines was investigated using the CCLE database; AFTPH was found to be highly expressed in four cancer cell lines. The relationship between AFTPH expression and patient prognosis was analyzed using GEPIA, LinkedOmics, and Kaplan–Meier plotter databases. Low expression of AFTPH was associated with improved prognosis for BRCA, DLBC, LUSC, and PAAD. Genetic alterations of AFTPH in cancers were explored using the cBioPortal website, revealing that gene copy number gains and amplification are common in BRCA, DLBC, LUSC, and PAAD. Related genes and markers associated with AFTPH were discovered using the LinkedOmics database. Furthermore, transfection of cells with AFTPH siRNA demonstrated that AFTPH exerts positive effects on cell proliferation in BRCA, LUSC, and PAAD cells. In conclusion, AFTPH may be a potential therapeutic target and prognostic biomarker for BRCA, DLBC, LUSC, and/or PAAD.

MicroRNA-674-5p induced by HIF-1α targets XBP-1 in intestinal epithelial cell injury during endotoxemia

Intestinal mucosal integrity dysfunction during endotoxemia can contribute to translocation of intestinal bacteria and a persistent systemic inflammatory response, which both fuel the pathophysiological development of sepsis or endotoxemia. The pathogenesis of intestinal damage induced by endotoxemia remains poorly understood. Here, we identified the microRNA (miR)-674-5p/X-box binding protein 1 (XBP-1) axis as a critical regulator and therapeutic target in preventing intestinal crypt cell proliferation during endotoxemia. MiR-674-5p was markedly increased in intestinal epithelial cells (IECs) during endotoxemia and its induction depended on hypoxia-inducible factor-1α (HIF-1α). Intriguingly, gene expression microanalysis revealed that expression of XBP-1 was down-regulated in IECs with over-expression of miR-674-5p. miR-674-5p was found to directly target XBP-1 protein expression. Upon in vitro, anti-miR-674-5p enhanced sXBP-1 expression and facilitated intestinal crypt cell proliferation. Blockade of miR-674-5p promoted XBP-1 activity, attenuated intestinal inflammation, and expedited intestinal regeneration, resulting in protection against endotoxemia-induced intestinal injury in mice. More importantly, the survival in endotoxemia mice was significantly improved by inhibiting intestinal miR-674-5p. Collectively, these data indicate that control of a novel miR-674-5p/XBP-1 signaling axis may mitigate endotoxemia -induced intestinal injury.

Absence of neurotensin attenuates intestinal dysbiosis and inflammation by maintaining Mmp7/α-defensin axis in diet-induced obese mice

We previously reported that high levels of plasma neurotensin (NT), a gut hormone released from enteroendocrine cells of the small bowel, contribute to obesity and comorbid conditions. Gut microbiota has been implicated in the obesity development. Paneth cells are critical in maintaining gut microbiota composition and homeostasis by releasing antimicrobial proteins including α-defensins. The purpose of our current study was to determine the possible role of NT in gut microbiota composition and α-defensin gene expression associated with obesity. Here we show that the ratio of Firmicutes/Bacteroidetes (F/B ratio) and intestinal proinflammatory cytokines is significantly increased in NT+/+ mice fed with a high-fat diet (HFD) which were improved in NT-deficient mice. HFD disrupted the intestinal Mmp7/α-defensin axis, which was completely prevented in NT-/- mice. In addition, NT treatment inhibited DEFA5 expression and concurrent NF-κB activity, which was blocked by a pan PKC inhibitor (Gö6983) or an inhibitor for atypical PKCs (CRT0066854). More importantly, the shRNA-mediated knockdown of atypical PKCτ reversed NT-attenuated DEFA5 expression and increased NF-κB activity. NT contributes to the HFD-induced disruption of gut microbiota composition and α-defensin expression. PKCτ/λ plays a central role in NT-mediated α-defensin gene expression which might be mediated through the inhibition of NF-κB signaling pathways in Paneth cells.

The Neuropeptide System and Colorectal Cancer Liver Metastases: Mechanisms and Management

Colorectal cancer (CRC), classified as the third most prevalent cancer worldwide, remains to be a clinical and research challenge. It is estimated that ~50% of CRC patients die from distant metastases, with treatment of this complication still posing significant difficulties. While liver metastasis (LM) cascade is known in the literature, its mechanisms are still unclear and remain studied in different research models. A connection is suggested between nervous system dysfunctions and a range of Neurotransmitters (Nts) (including Neuropeptides, NPs), Neurotrophins (Ntt) and their receptors (Rs) in CRC liver metastasis development. Studies on the role of NP/NP-Rs in the progression and metastasis of CRC, show the complexity of brain–tumor interactions, caused by their different forms of release to the extracellular environment (endocrine, autocrine, paracrine and neurocrine). Many stages of LM are connected to the activity of pro-inflammatory, e.g., Corticotropin-releasing Hormone Receptor 1 (CRHR1), Neuropeptide Y (NPY) and Neurotensin (NT), anti-inflammatory, e.g., Calcitonin Gene-related Peptide (CGRP), CRHR2 and Vasoactive Intestinal Polypeptide (VIP) or dual role neuropeptides, e.g., Substance P (SP). The regulation of the local immunological profile (e.g., CRH/CRHRs), dysfunctions of enteroprotective role of NPs on epithelial cells (e.g., NT/NT-R), as well as structural-functional changes in enteric nervous system innervation of the tumor are also important. More research is needed to understand the exact mechanisms of communication between the neurons and tumor cells. The knowledge on the mechanisms regulating tumor growth and different stages of metastasis, as well as effects of the action of a numerous group of Nts/NPs/Ntt as growth factors, have implications for future therapeutic strategies. To obtain the best treatment outcomes, it is important to use signaling pathways common for many NPs, as well to develop a range of broad-spectrum antagonists. This review aims to summarize the current knowledge on the importance of neuroactive molecules in the promotion of the invasion-metastasis cascade in CRC, as well as the improvements of clinical management of CRC liver metastasis.

The Neuropeptide System and Colorectal Cancer Liver Metastases: Mechanisms and Management

Colorectal cancer (CRC), classified as the third most prevalent cancer worldwide, remains to be a clinical and research challenge. It is estimated that ~50% of CRC patients die from distant metastases, with treatment of this complication still posing significant difficulties. While liver metastasis (LM) cascade is known in the literature, its mechanisms are still unclear and remain studied in different research models. A connection is suggested between nervous system dysfunctions and a range of Neurotransmitters (Nts) (including Neuropeptides, NPs), Neurotrophins (Ntt) and their receptors (Rs) in CRC liver metastasis development. Studies on the role of NP/NP-Rs in the progression and metastasis of CRC, show the complexity of brain–tumor interactions, caused by their different forms of release to the extracellular environment (endocrine, autocrine, paracrine and neurocrine). Many stages of LM are connected to the activity of pro-inflammatory, e.g., Corticotropin-releasing Hormone Receptor 1 (CRHR1), Neuropeptide Y (NPY) and Neurotensin (NT), anti-inflammatory, e.g., Calcitonin Gene-related Peptide (CGRP), CRHR2 and Vasoactive Intestinal Polypeptide (VIP) or dual role neuropeptides, e.g., Substance P (SP). The regulation of the local immunological profile (e.g., CRH/CRHRs), dysfunctions of enteroprotective role of NPs on epithelial cells (e.g., NT/NT-R), as well as structural-functional changes in enteric nervous system innervation of the tumor are also important. More research is needed to understand the exact mechanisms of communication between the neurons and tumor cells. The knowledge on the mechanisms regulating tumor growth and different stages of metastasis, as well as effects of the action of a numerous group of Nts/NPs/Ntt as growth factors, have implications for future therapeutic strategies. To obtain the best treatment outcomes, it is important to use signaling pathways common for many NPs, as well to develop a range of broad-spectrum antagonists. This review aims to summarize the current knowledge on the importance of neuroactive molecules in the promotion of the invasion-metastasis cascade in CRC, as well as the improvements of clinical management of CRC liver metastasis.

Crosstalk of MicroRNAs and Oxidative Stress in the Pathogenesis of Cancer

Oxidative stress refers to an imbalance between reactive oxygen species (ROS) generation and body's capability to detoxify the reactive mediators or to fix the relating damage. MicroRNAs are considered to be important mediators that play essential roles in the regulation of diverse aspects of carcinogenesis. Growing studies have demonstrated that the ROS can regulate microRNA biogenesis and expression mainly through modulating biogenesis course, transcription factors, and epigenetic changes. On the other hand, microRNAs may in turn modulate the redox signaling pathways, altering their integrity, stability, and functionality, thus contributing to the pathogenesis of multiple diseases. Both ROS and microRNAs have been identified to be important regulators and potential therapeutic targets in cancers. However, the information about the interplay between oxidative stress and microRNA regulation is still limited. The present review is aimed at summarizing the current understanding of molecular crosstalk between microRNAs and the generation of ROS in the pathogenesis of cancer.

High miR-31-5p expression promotes colon adenocarcinoma progression by targeting TNS1

Overexpression of the miR-31-5p contributes to tumorigenesis and metastasis in diverse neoplasms. In this study, we evaluated expression of miR-31-5p in patients with colon adenocarcinoma (COAD). We found that miR-31-5p was overexpressed in four cohorts (GSE30454, GSE41655, GSE18392, GSE108153) of COAD patients. Importantly, a LinkedOmics analysis revealed that high miR-31-5p expression was associated with poor overall survival of COAD patients. At total of 133 putative target genes of miR-31-5p were identified from TargetScan, miRDB, and TargetMiner. After integrating the target genes with 1,556 deregulated genes in COAD, 8 were acquired that may be targeted by miR-31-5p and contribute to COAD progression. Among these, tensin 1 (TNS1) showed the greatest prognostic ability in COAD and was strongly correlated with M2 macrophages, regulatory T cells, and other immune cells. These findings indicate that, in COAD, miR-31-5p is a potential prognostic factor that affects immune infiltration by targeting TNS1.

Inhibitory Effect of Corilagin on miR-21-Regulated Hepatic Fibrosis Signaling Pathway

Corilagin is a polyphenol that can be extracted from many medicinal plants and shows multiple pharmacological effects. We aimed to investigate the role of corilagin on miR-21-regulated hepatic fibrosis, especially miR-21-regulated TGF-β1/Smad signaling pathway, in hepatic stellate LX2 cell line and Sprague-Dawley rats. The mRNA or protein levels of miR-21, Smad7, connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinase-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), collagen type I alpha 1 (COL1A1), Smad2, Smad3, Smad2/3, p-Smad2, p-Smad3, p-Smad2/3, and transforming growth factor-β1 (TGF-β1) in LX2 cells and liver tissues were determined. Furthermore, gain-of and loss-of function of miR-21 in miR-21-regulated TGF-β1/Smad signaling pathway were analyzed in LX2 cells. Liver tissues and serum were collected for pathological analysis, immunohistochemical staining, and enzyme-linked immunosorbent assay (ELISA). Corilagin treatment reduced mRNA or protein levels of miR-21, CTGF, α-SMA, TIMP-1, TGF-β1, COL1A1, p-Smad2, p-Smad3, and p-Smad2/3 both in vitro and in vivo. While corilagin increased mRNA and protein levels of Smad7 and MMP-9. After gain-of and loss-of function of miR-21, the downstream effectors of miR-21-regulated TGF-β1/Smad signaling pathway in LX2 cells changed accordingly, and the changes were inhibited by corilagin. Simultaneously, administration of corilagin not only ameliorated pathological manifestation of liver fibrosis but also reduced levels of α-SMA and COL1A1 in liver tissues and TGF-β1, ALT levels in serum. Corilagin is able to potentially prevent liver fibrosis by blocking the miR-21-regulated TGF-β1/Smad signaling pathway in LX2 cells and CCl₄-induced liver fibrosis rats, which may provide a novel therapeutic strategy for liver fibrosis.

MicroRNAs that regulate PTEN as potential biomarkers in colorectal cancer: a systematic review

PURPOSE

MicroRNAs (miRNAs) participate in a variety of biological processes, including tumorigenesis, progression, invasion, and drug resistance to multiple cancers. Phosphatase and tensin homolog (PTEN) is a cancer suppressor gene that has been certified to be regulated by miRNAs in various tumors, including colorectal cancer (CRC). In this review, we screened articles focusing on low PTEN expression in CRC, observed the expression of related miRNAs, analyzed their correlation and relationship with clinicopathological features, and discussed the possibility of these miRNAs as prognostic molecules.

METHODS

We conducted a systematic search for articles published in the Web of Science, PubMed and EBSCO databases between January 1, 2002, and July 18, 2019. We identified these studies by using combinations of the following index entries and key words: 'colorectal tumor OR colorectal neoplasm OR colorectal carcinoma OR colorectal cancer OR CRC', 'protein tyrosine phosphatase OR PTEN', and 'microRNA OR MiRNA OR miRNA OR MicroRNA'. Moreover, we evaluated the underlying association between alterations in PTEN and CRC prognosis.

RESULTS

PTEN expression was obviously lower in CRC tissues than in normal mucosa. However, PTEN expression did not differ significantly between adenoma and normal tissues. PTEN tends to be negatively associated with tumor size and metastasis. MiR-21, miR-200a, miR-543, miR-32, miR-92a, miR-26a, miR-106a and miR-181a were correlated with the downregulation of PTEN. MiR-26a, miR-106a and miR-181a were obviously higher in CRC tissues than in normal tissues, while PTEN was downregulated in CRC tissues. Additionally, miRNAs were mainly positively correlated with distant metastasis, followed by TNM stage. The relationship between miRNAs and tumor differentiation is controversial. However, there were no significant differences between miRNAs and either sex or age.

CONCLUSIONS

The loss of PTEN may be a diagnostic factor for CRC patients. The above-mentioned miRNAs may function as oncogenes in CRC and represent potential targets for CRC therapy. However, further prospective clinical studies are necessary.

MiR-155-5p promotes oral cancer progression by targeting chromatin remodeling gene ARID2

BACKGROUND

Dysregulation of miRNAs is associated with aberrant migration and invasion by suppressing relevant target genes in multiple cancers, including oral squamous cell carcinoma (OSCC). Accumulating evidence suggests that microRNA-155-5p is involved in carcinogenesis and tumor progression. However, the exact function and molecular mechanism of miR-155-5p in OSCC remain unclear. This study aimed to investigate the function of miR-155-5p and the molecular mechanisms underlying the influencing progression of OSCC.

METHODS

The miR-155-5p expression level in the OSCC tissues and oral cancer cell lines were determined by the qRT-PCR. Gain-of-function and knockdown approach were used to examine the effect of miR-155-5p on cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of OSCC. The luciferase reporter assay was applied to confirm the AT-rich interactive domain 2 (ARID2) as a potential target of miR-155-5p, and the rescue experiment was employed to verify the roles of the miRNA-155-5p-ARID2 axis in OSCC progression. Immunohistochemical staining was used to detect ARID2 expression in another cohort sample tissues from OSCC patients.

RESULTS

MiR-155-5p was significantly upregulated in OSCC tissues and cell lines. The miR-155-5p expression level was positively correlated with tumor size, TNM stage, histological grade and lymph node metastasis of OSCC patients. Functional assays demonstrated that miR-155-5p enhanced OSCC cell proliferation, migration and invasion. Mechanistically, ARID2 was identified as a direct target and functional effector of miR-155-5p in OSCC. Furthermore, ARID2 overexpression could rescue the aberrant biological function by overexpressed miR-155-5p in OSCC cells. Notably, we showed that ARID2 could be used as an independent prognosis factor in OSCC.

CONCLUSIONS

Our results suggest that miR-155-5p facilitates tumor progression of OSCC by targeting ARID2, and miR-155-5p-ARID2 axis may be a potential therapeutic target of OSCC.

Changes in plasma levels of cholecystokinin, neurotensin, VIP and PYY in gastric and colorectal cancer - Preliminary results

Physiological roles of enterohormones such as secretion, absorption and digestion were supported by clinical data. Overexpression of cholecystokinin (CCK), neurotensin (NT) and vasoactive intestinal peptide (VIP) receptors occur in gastrointestinal (GI) malignancies. The aim of the paper was to compare plasma levels of CCK, peptide YY (PYY), VIP and NT in patients with gastrointestinal malignancies and healthy controls. The study included 80 patients (37 men and 43 women) with GI malignancies (20 with gastric and 60 with colorectal cancers). Median age of the patients was 62.9 years (range: 40-85 years). Control group was comprised of 30 healthy persons with median age 59.8 years (range: 40-82 years). Fasting plasma concentrations of CKK, PYY, NT, and VIP were determined at rest, using ELISA kits for automated systems. Comparative analysis of enterohormone levels in patients with various types of gastrointestinal malignancies demonstrated presence of some cancer-specific alterations. Patients with gastric cancers presented with lower plasma concentrations of CCK than healthy controls and individuals from colorectal cancers (p = 0.02). The highest plasma concentrations of neurotensin was found in colorectal cancer patients in comparison to gastric (p = 0.02). The plasma levels of VIP observed in gastric cancer group were lower than in colorectal cancer patients (p = 0.01). Patients with GI malignancies may present with tumor-specific alterations in plasma enterohormone levels.

MiR-21 in Substance P-induced exosomes promotes cell proliferation and migration in human colonic epithelial cells

Exosomes are cellular vesicles involved in intercellular communication via their specialized molecular cargo, such as miRNAs. Substance P (SP), a neuropeptide/hormone, and its high-affinity receptor, NK-1R, are highly expressed during colonic inflammation. Our previous studies show that SP/NK-1R signaling stimulates differential miRNA expression and promotes colonic epithelial cell proliferation. In this study, we examined whether SP/NK-1R signaling regulates exosome biogenesis and exosome-miRNA cargo sorting. Moreover, we examined the role of SP/NK-1R signaling in exosome-regulated cell proliferation and migration. Exosomes produced by human colonic NCM460 epithelial cells overexpressing NK-1R (NCM460-NK1R) were isolated from culture media. Exosome abundance and uptake were assessed by Western blot analysis (abundance) and Exo-Green fluorescence microscopy (abundance and uptake). Cargo-miRNA levels were assessed by RT-PCR. Cell proliferation and migration were assessed using xCELLigence technology. Colonic epithelial exosomes were isolated from mice pretreated with SP for 3 days. Cell proliferation in vivo was assessed by Ki-67 staining. SP/NK-1R signaling in human colonic epithelial cells (in vitro) and mouse colons (in vivo) increased 1) exosome production, 2) the level of fluorescence in NCM460s treated with Exo-Green-labeled exosomes, and 3) the level of miR-21 in exosome cargo. Moreover, our results showed that SP/NK-1R-induced cell proliferation and migration are at least in part dependent on intercellular communication via exosomal miR-21 in vitro and in vivo. Our results demonstrate that SP/NK-1R signaling regulates exosome biogenesis and induces its miR-21 cargo sorting. Moreover, exosomal miR-21 promotes proliferation and migration of target cells.NEW & NOTEWORTHY Substance P signaling regulates exosome production in human colonic epithelial cells and colonic crypts in wild-type mice. MiR-21 is selectively sorted into exosomes induced by Substance P stimulation and promotes cell proliferation and migration in human colonocytes and mouse colonic crypts.

Regulatory mechanisms of microRNAs in colorectal cancer and colorectal cancer stem cells

Colorectal cancer (CRC) is one of the most lethal and hard-to-treat cancers in the world, which in its advanced stages, surgery and chemotherapy are the main common treatment approaches. The microRNAs (miRNAs), as novel markers for CRC detection, promote their regulatory effects via the 3'-untranslated binding region (3'-UTR) of target messenger RNA in posttranscriptional regulation of genes and also play a pivotal role in modulating resistance to chemotherapeutic agents. These small noncoding RNAs have also a critical role in CRC stem cells (CRCSCs) regulation, comprising self-renewal, differentiation, and tumorigenesis. Cancer stem cells (CSCs) are distinctive cell types inside a tumor tissue that are believed to derive from normal somatic stem cells. The CSCs have self-renewal abilities, angiogenesis, as well as specific surface markers expression characteristics. Furthermore, they are frequently criticized for tumor maintenance, treatment resistance, tumor development, and distant metastasis. In this review, we discuss the current understandings of CRCSCs and their environment with a focus on the role of miRNAs on the regulation of CSCs and their targeting application in CRC treatment.

Phytochemical Modulation of MiRNAs in Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of death in the United States. Chemotherapy and radiotherapy are some of the most commonly used treatments, but are often associated with severe side effects, and are not entirely curative. It is therefore important to consider other preventative treatment options. Phytochemicals are naturally occurring bioactive compounds which have been shown to play a role in cancer prevention and treatment, especially in regards to a person’s lifestyle and diet. Recent evidence has shown that phytochemicals may exert their chemopreventative effects by targeting micro RNAs (miRNAs), which regulate the downstream expression of tumor suppressors and oncogenes. MiRNAs are small, endogenous, noncoding RNAs that regulate several biological processes through post-translational regulation. The dysregulation of miRNA expression has been shown to be associated with colorectal cancer. In this review, we will summarize and discuss several phytochemicals, which have been shown to exert chemopreventative effects in colorectal cancer by the modulation of miRNA expression.

The emerging role of lncRNAs in inflammatory bowel disease

Dysregulation of long noncoding RNA (lncRNA) expression is linked to the development of various diseases. Recently, an emerging body of evidence has indicated that lncRNAs play important roles in the pathogenesis of inflammatory bowel diseases (IBDs), including Crohn’s disease (CD) and ulcerative Colitis (UC). In IBD, lncRNAs have been shown to be involved in diverse processes, including the regulation of intestinal epithelial cell apoptosis, association with lipid metabolism, and cell–cell interactions, thereby enhancing inflammation and the functional regulation of regulatory T cells. In this review, we aim to summarize the current knowledge regarding the role of lncRNAs in IBD and highlight potential avenues for future investigation. We also collate potentially immune-relevant, IBD-associated lncRNAs identified through a built-by association analysis with respect to their neighboring protein-coding genes within IBD-susceptible loci. We further underscore their importance by highlighting their enrichment for various aspects of immune system regulation, including antigen processing/presentation, immune cell proliferation and differentiation, and chronic inflammatory responses. Finally, we summarize the potential of lncRNAs as diagnostic biomarkers in IBD.

Studying long noncoding RNAs (lncRNAs) may improve diagnosis and treatment of inflammatory bowel disease (IBD). These RNAs are found between genes in DNA regions previously thought to be “junk,” and have recently been shown to be important in development of various diseases. IBD, which includes both Crohn’s disease and ulcerative colitis, damages the digestive tract lining, causing pain and chronic diarrhea. A better understanding of IBD’s complex causes is needed to identify more effective treatments. Flemming Pociot at the Steno Diabetes Center in Gentofte, Denmark, and co-workers reviewed recent research linking lncRNAs and IBD. They discuss how lncRNAs’ roles in immunity and inflammation influence IBD development, describing how particular lncRNAs are related to IBD. Promising avenues for further research are highlighted, including the use of lncRNAs as biomarkers of IBD, which can be difficult to diagnose.

Validation of Neurotensin Receptor 1 as a Therapeutic Target for Gastric Cancer

Gastric cancer is the fifth most common type of malignancy worldwide, and the survival rate of patients with advanced-stage gastric cancer is low, even after receiving chemotherapy. Here, we validated neurotensin receptor 1 (NTSR1) as a potential therapeutic target in gastric cancer. We compared NTSR1 expression levels in sixty different gastric cancer-tissue samples and cells, as well as in other cancer cells (lung, breast, pancreatic, and colon), by assessing NTSR1 expression via semi-quantitative real-time reverse transcription polymerase chain reaction, immunocytochemistry and western blot. Following neurotensin (NT) treatment, we analyzed the expression and activity of matrix metalloproteinase-9 (MMP-9) and further determined the effects on cell migration and invasion via wound-healing and transwell assays. Our results revealed that NTSR1 mRNA levels were higher in gastric cancer tissues than non-cancerous tissues. Both of NTSR1 mRNA levels and expression were higher in gastric cancer cell lines relative to levels observed in other cancer-cell lines. Moreover, NT treatment induced MMP-9 expression and activity in all cancer cell lines, which was significantly decreased following treatment with the NTSR1 antagonist SR48692 or small-interfering RNA targeting NTSR1. Furthermore, NT-mediated metastases was confirmed by observing epithelial-mesenchymal transition markers SNAIL and E-cadherin in gastric cancer cells. NT-mediated invasion and migration of gastric cancer cells were reduced by NTSR1 depletion through the Erk signaling. These findings strongly suggested that NTR1 constitutes a potential therapeutic target for the inhibition of gastric cancer invasion and metastasis.

Oncogenic role of neurotensin and neurotensin receptors in various cancers

Neurotensin (NTS) has long been recognized as a neurotransmitter or neuromodulator in the central nervous system and as an endocrine agent in the periphery via actions mediated through neurotensin receptors (NTSRs). Many studies support a role for NTS in the endocrine, autocrine and paracrine growth stimulation of cancer, with oncogenic actions described for NTS in different types of cancers and cancer cell lines at each step of cancer progression, ranging from tumour growth and survival to metastatic spread. The mechanisms underlying the effects of the NTS/NTSR system in cell proliferation, migration and invasion, as well as the anti-apoptotic effects of this system, have been elucidated in different types of cancers, and include mitogen-activated protein kinases, phosphatidylinositol 3-kinase and RhoGTPases. The present mini review summarizes recent findings relating to the oncogenic function of the NTS/NTSR system.

Targeted delivery of anti-miR-155 by functionalized mesoporous silica nanoparticles for colorectal cancer therapy

INTRODUCTION

MicroRNA-155 (miR-155) is an oncogenic microRNA, which is upregulated in many human cancers including colorectal cancer (CRC). Overexpression of miR-155 has been found to regulate several cancer-related pathways, and therefore, targeting miR-155 may be an effective strategy for cancer therapy. However, effective and safe delivery of anti-miR-155 to tumors remains challenging for the clinical applications of anti-miR-155-based therapeutics.

METHODS

In this study, we explored the expression of miR-155 and the transcription factor nuclear factor kappa B (NF-κB) in CRC tissues and cell lines, and the possible relationship between miR-155 and NF-κB. We further report on anti-miR-155-loaded mesoporous silica nanoparticles (MSNs) modified with polymerized dopamine (PDA) and AS1411 aptamer (MSNs-anti-miR-155@PDA-Apt) for the targeted treatment of CRC.

RESULTS

Results showed that miR-155 is overexpressed in CRC tissues and cell lines, and there is a positive feedback loop between NF-κB and miR-155. Compared to the control groups, MSNs-anti-miR-155@PDA-Apt could efficiently downregulate miR-155 expression in SW480 cells and achieve significantly high targeting efficiency and enhanced therapeutic effects in both in vivo and in vitro experiments. Furthermore, inhibition of miR-155 by MSNs-anti-miR-155@PDA-Apt can enhance the sensitivity of SW480 to 5-fluorouracil chemotherapy.

CONCLUSION

Thus, our results suggested that MSNs-anti-miR-155@PDA-Apt is a promising nanoformulation for CRC treatment.

Concentration of circulating miRNA-containing particles in serum enhances miRNA detection and reflects CRC tissue-related deregulations

The emerging potential of miRNAs as biomarkers for cancer detection demands parallel evaluation of strategies for reliable identification of disease-related signatures from easily accessible and pertinent body compartments. Here, we addressed whether efficient concentration of circulating miRNA-carrying particles is a rationale for miRNA biomarker discovery. We systematically compared miRNA signatures in 93 RNA preparations from three serum entities (whole serum, particle-concentrated, and particle-depleted fractions) and corresponding tissue samples from patients with colorectal cancer (CRC) as a model disease. Significant differences between whole sera and particle-concentrated serum fractions of CRC patients emerged for 45 of 742 tested miRNAs. Twenty-eight of these 45 miRNAs were differentially expressed between particle-concentrated serum fractions of metastatic CRC- and healthy individuals. Over half of these candidates (15 of 28) showed deregulations only in concentrated serum fractions, but not in whole sera, compared to the respective controls.Our results also provided evidence of a consistent downregulation of miR-486 and miR-92a, and further showed a possible "strand-specific" deregulation of extracellular miRNAs in CRC. More importantly, most of the identified miRNAs in the enriched sera reflected the patterns of the corresponding tumor tissues and showed links to cancer-related inflammation. Further investigation of seven serum pools revealed a subset of potential extracellular miRNA candidates to be implicated in both neoplastic and inflammatory bowel disease.Our findings demonstrate that enrichment and sensitive detection of miRNA carriers is a promising approach to detect CRC-related pathological changes in liquid biopsies, and has potential for clinical diagnostics.

New extracellular factors in glioblastoma multiforme development: neurotensin, growth differentiation factor-15, sphingosine-1-phosphate and cytomegalovirus infection

Recent years have seen considerable progress in understanding the biochemistry of cancer. For example, more significance is now assigned to the tumor microenvironment, especially with regard to intercellular signaling in the tumor niche which depends on many factors secreted by tumor cells. In addition, great progress has been made in understanding the influence of factors such as neurotensin, growth differentiation factor-15 (GDF-15), sphingosine-1-phosphate (S1P), and infection with cytomegalovirus (CMV) on the 'hallmarks of cancer' in glioblastoma multiforme. Therefore, in the present work we describe the influence of these factors on the proliferation and apoptosis of neoplastic cells, cancer stem cells, angiogenesis, migration and invasion, and cancer immune evasion in a glioblastoma multiforme tumor. In particular, we discuss the effect of neurotensin, GDF-15, S1P (including the drug FTY720), and infection with CMV on tumor-associated macrophages (TAM), microglial cells, neutrophil and regulatory T cells (T_reg), on the tumor microenvironment. In order to better understand the role of the aforementioned factors in tumoral processes, we outline the latest models of intratumoral heterogeneity in glioblastoma multiforme. Based on the most recent reports, we discuss the problems of multi-drug therapy in treating glioblastoma multiforme.

Computational identification of microRNAs and their targets in liver cirrhosis

Previous studies have revealed that the deregulation of circulating miRNAs is associated with liver cirrhosis. The present study aimed to identify reliable candidate biomarkers to improve the early detection of liver cirrhosis. An integrated analysis of expression profiles of microRNAs (miRNAs/miRs) and mRNAs in liver cirrhosis tissues from the GEO database was performed. Next, the regulatory targets of the differentially expressed miRNAs in liver cirrhosis tissues were predicted. In addition, a regulatory network of miRNA-target genes was constructed. A total of 4 eligible mRNA expression profiling studies and 2 miRNA expression profiling studies met the inclusion criteria, and were thus included. A total of 48 differentially expressed miRNAs and 1,773 differentially expressed genes were identified in liver cirrhosis tissues compared with normal tissues. There were 240 miRNA-target pairs whose expression was negatively correlated. In the miRNA-target regulatory network, overexpression of miR-21 and miR-199a-3p was suggested to be closely associated with the progression of liver cirrhosis. In addition, functional enrichment analysis of the target genes indicated that cell cycle was the most significantly enriched pathway, and the dysregulation of leukemia inhibitory factor, cancerous inhibitor of protein phosphatase 2A and retinoblastoma-associated protein 1 clearly suggested their importance in the development of liver cirrhosis. We hypothesized that miR-21 and miR-199a-3p may be promising non-invasive diagnostic biomarkers for the early diagnosis of liver cirrhosis. The miRNA-target regulatory network may provide additional insight into the current data regarding the role of miRNAs in liver cirrhosis.

MicroRNAs in the etiology of colorectal cancer: pathways and clinical implications

MicroRNAs (miRNAs) are small single-stranded RNAs that repress mRNA translation and trigger mRNA degradation. Of the ∼1900 miRNA-encoding genes present in the human genome, ∼250 miRNAs are reported to have changes in abundance or altered functions in colorectal cancer. Thousands of studies have documented aberrant miRNA levels in colorectal cancer, with some miRNAs reported to actively regulate tumorigenesis. A recurrent phenomenon with miRNAs is their frequent participation in feedback loops, which probably serve to reinforce or magnify biological outcomes to manifest a particular cellular phenotype. Here, we review the roles of oncogenic miRNAs (oncomiRs), tumor suppressive miRNAs (anti-oncomiRs) and miRNA regulators in colorectal cancer. Given their stability in patient-derived samples and ease of detection with standard and novel techniques, we also discuss the potential use of miRNAs as biomarkers in the diagnosis of colorectal cancer and as prognostic indicators of this disease. MiRNAs also represent attractive candidates for targeted therapies because their function can be manipulated through the use of synthetic antagonists and miRNA mimics.

Summary: This Review provides an overview of some important microRNAs and their roles in colorectal cancer.

Role of G protein-coupled receptors-microRNA interactions in gastrointestinal pathophysiology

G protein-coupled receptors (GPCRs) make up the largest transmembrane receptor superfamily in the human genome and are expressed in nearly all gastrointestinal cell types. Coupling of GPCRs and their respective ligands activates various phosphotransferases in the cytoplasm, and, thus, activation of GPCR signaling in intestine regulates many cellular and physiological processes. Studies in microRNAs (miRNAs) demonstrate that they represent critical epigenetic regulators of different pathophysiological responses in different organs and cell types in humans and animals. Here, we reviewed recent research on GPCR-miRNA interactions related to gastrointestinal pathophysiology, such as inflammatory bowel diseases, irritable bowel syndrome, and gastrointestinal cancers. Given that the presence of different types of cells in the gastrointestinal tract suggests the importance of cell-cell interactions in maintaining gastrointestinal homeostasis, we also discuss how GPCR-miRNA interactions regulate gene expression at the cellular level and subsequently modulate gastrointestinal pathophysiology through molecular regulatory circuits and cell-cell interactions. These studies helped identify novel molecular pathways leading to the discovery of potential biomarkers for gastrointestinal diseases.

The role of enteric neurons in the development and progression of colorectal cancer

The enteric nervous system (ENS) is the intrinsic neural network of the gastrointestinal tract, which is essential for regulating gut functions and intestinal homeostasis. The importance of the ENS is underscored by the existence of severe gastrointestinal diseases, such as Hirschsprung's disease and intestinal pseudo-obstruction, which arise when the ENS fails to develop normally or becomes dysregulated. Moreover, it is known that enteric neurons are involved in intestinal inflammation. However, the role of the ENS in colorectal cancer (CRC) carcinogenesis remains poorly understood, even though processes like perineural invasion and neoneurogenesis are important factors in CRC. Here we summarize how enteric neurons are affected during CRC and discuss the influence of enteric neurons, either direct or indirect, on the development and/or progression of CRC. Finally, we illustrate how the ENS could be targeted as a potential anti-cancer therapy, establishing the ENS as an integral part of the tumor microenvironment.

Inhibition of neurotensin receptor 1 induces intrinsic apoptosis via let-7a-3p/Bcl-w axis in glioblastoma

Backgroud:

Glioblastoma is a kind of highly malignant and aggressive tumours in the central nervous system. Previously, we found that neurotensin (NTS) and its high-affinity receptor 1 (NTSR1) had essential roles in cell proliferation and invasiveness of glioblastoma. Unexpectedly, cell death also appeared by inhibition of NTSR1 except for cell cycle arrest. However, the mechanisms were remained to be further explored.

Methods:

Cells treated with SR48692, a selective antagonist of NTSR1, or NTSR1 shRNA were stained with Annexin V-FITC/PI and the apoptosis was assessed by flow cytometry. Cytochrome c release was detected by using immunofluorescence. Mitochondrial membrane potential (MMP, ΔΨm) loss was stained by JC-1 and detected by immunofluorescence or flow cytometry. Apoptosis antibody array and microRNA microarray were performed to seek the potential regulators of NTSR1 inhibition-induced apoptosis. Interaction between let-7a-3p and Bcl-w 3′UTR was evaluated by using luciferase assay.

Results:

SR48692 induced massive apoptosis, which was related to mitochondrial cytochrome c release and MMP loss. Knockdown of NTSR1 induced slight apoptosis and significant MMP loss. In addition, NTSR1 inhibition sensitised glioblastoma cells to actinomycin D or doxorubicin-induced apoptosis. Consistently, NTSR1 inhibition-induced mitochondrial apoptosis was accompanied by downregulation of Bcl-w and Bcl-2. Restoration of Bcl-w partly rescued NTSR1 deficiency-induced apoptosis. In addition, NTSR1 deficiency promoted higher let-7a-3p expression and inhibition let-7a-3p partly rescued NTSR1 inhibition-induced apoptosis. In addition, let-7a-3p inhibition promoted 3′UTR activities of Bcl-w and the expression of c-Myc and LIN28, which were the upstream of let-7a-3p, decreased after NTSR1 inhibition.

Conclusions:

NTSR1 had an important role in protecting glioblastoma from intrinsic apoptosis via c-Myc/LIN28/let-7a-3p/Bcl-w axis.

Long-term Inflammation Transforms Intestinal Epithelial Cells of Colonic Organoids

BACKGROUND AND AIMS

Patients with ulcerative colitis [UC] are at an increased risk of developing colitis-associated cancer [CAC], suggesting that continuous inflammation in the colon promotes the transformation of colonic epithelial cells. However, the mechanisms underlying cell transformation in UC remain unknown. We therefore aimed to investigate the effect of long-term inflammation on intestinal epithelial cells [IECs] using organoid culture.

METHODS

IECs were isolated from mouse colon, and were cultured according to a method for a three-dimensional [3D] organoid culture. To mimic chronic inflammation, a mixture of cytokines and bacterial components were added to the medium for over a year. Cell signal intensity was assessed by 3D immunofluorescence. Cell transformation was assessed by microarray with gene set enrichment analysis.

RESULTS

Stimulation with cytokines resulted in a significant induction of target genes for the nuclear factor [NF]-κB pathway in colonic organoids. Following 60 weeks of continuous stimulation, cell differentiation was suppressed. Continuous stimulation also resulted in significant amplification of NF-κB signalling. Amplified NF-κB signalling by long-term stimulation remained in colonic organoids even 11 weeks after the removal of all cytokines. Some genes were specifically upregulated only in colonic organoids after the removal all cytokines following long-term stimulation.

CONCLUSIONS

Colonic organoids stimulated with cytokines for a prolonged period were established as in vitro model to assess long-term epithelial responses to inflammatory cytokines. Chronic inflammation led to sustained NF-κB signalling activation in colonic organoids, resulting in cell transformation that might be related to the carcinogenesis of CAC in UC.

A Review of the Role of Neurotensin and Its Receptors in Colorectal Cancer

Neurotensin (NTS) is a physiologically occurring hormone which affects the function of the gastrointestinal (GI) tract. In recent years, NTS, acting through its cellular receptors (NTSR), has been implicated in the carcinogenesis of several cancers. In colorectal cancer (CRC), a significant body of evidence, from in vitro and in vivo studies, is available which elucidates the molecular biology of NTS/NTSR signalling and the resultant growth of CRC cells. There is growing clinical data from human studies which corroborate the role NTS/NTSR plays in the development of human CRC. Furthermore, blockade and modulation of the NTS/NTSR signalling pathways appears to reduce CRC growth in cell cultures and animal studies. Lastly, NTS/NTSR also shows potential of being utilised as a diagnostic biomarker for cancers as well as targets for functional imaging. We summarise the existing evidence and understanding of the role of NTS and its receptors in CRC.

Role of cancer-related inflammation in colon cancer

Chronic inflammation is one of the important mechanisms for the development of colon cancer, and the role of cancer-related inflammation (CRI) in tumor development is a hot research topic in recent years. Therefore, it is very important to clarify the effect and regulation of CRI in colon cancer. Accumulating evidence indicates that transcription factors, cytokines, chemokines, cyclooxygenase-2 and microRNAs play key roles in CRI. This review focuses on the research progress about these molecules in colon cancer.