MicroRNA-155 deletion promotes tumorigenesis in the azoxymethane-dextran sulfate sodium model of colon cancer

Dysregulated microRNAs participate in the crosstalk between colorectal cancer and atrial fibrillation

Colorectal cancer and atrial fibrillation share several common risk factors, and the incidence of the two diseases also exhibits a certain correlation. The above facts suggest a potential interaction mechanism between them, which has obtained increasing attention in the scientific community but remains to be further explored. Participating in diverse physiological and pathological processes, miRNAs exert important roles in both occurrence and growth of colorectal cancer and atrial fibrillation. To fill the gap in the understanding of the potential linkage between two diseases, the present study collected dysregulated miRNAs of colorectal cancer and atrial fibrillation from previous studies and then selected the miRNAs with the same change trends in both diseases. Finally, we reviewed the potential crosstalk of two diseases focusing on the roles of 6 dysregulated miRNAs, including 3 co-downregulated miRNAs (hsa-mir-126, hsa-mir-133a and hsa-mir-150) and 3 co-upregulated miRNAs (hsa-mir-106a, hsa-mir-155 and hsa-mir-21). The molecular mechanisms mediated by these miRNAs in colorectal cancer and atrial fibrillation were reviewed, and the possible crosstalk between the two diseases was discussed from the perspective of miRNAs. This study also provides potential common targets for preventive and curative measures against both colorectal cancer and atrial fibrillation.

Acute Administration of Ojeok-san Ameliorates Pain-like Behaviors in Pre-Clinical Models of Inflammatory Bowel Diseases

(1) Background: Gastrointestinal pain and fatigue are the most reported concerns of patients with inflammatory bowel disease (IBD). Commonly prescribed drugs focus on decreasing excessive inflammation. However, up to 20% of IBD patients in an "inactive" state experience abdominal pain. The medicinal herb Ojeok-san (OJS) has shown promise in the amelioration of visceral pain. However, no research on OJS has been conducted in preclinical models of IBD. The mechanism by which OJS promotes analgesia is still elusive, and it is unclear if OJS possesses addictive properties. (2) Aims: In this study, we examined the potential of OJS to promote analgesic effects and rewarding behavior. Additionally, we investigated if tumor necrosis factor alpha (TNFα) from macrophages is a primary culprit of IBD-induced nociception. (3) Methods: Multiple animal models of IBD were used to determine if OJS can reduce visceral nociception. TNFα-macrophage deficient mice were used to investigate the mechanism of action by which OJS reduces nociceptive behavior. Mechanical sensitivity and operant conditioning tests were used to determine the analgesic and rewarding effects of OJS. Body weight, colon length/weight, blood in stool, colonic inflammation, and complete blood count were assessed to determine disease progression. (4) Results: OJS reduced the evoked mechanical nociception in the dextran sulphate sodium model of colitis and IL-10 knockout (KO) mice and delayed aversion to colorectal distension in C57BL/6 mice. No rewarding behavior was observed in OJS-treated IL-10 KO and mdr1a KO mice. The analgesic effects of OJS are independent of macrophage TNFα levels and IBD progression. (5) Conclusions: OJS ameliorated elicited mechanical and visceral nociception without producing rewarding effects. The analgesic effects of OJS are not mediated by macrophage TNFα.

miR155 deficiency reduces breast tumor burden in the MMTV-PyMT mouse model

miRNA155 (miR155) has emerged as an important regulator of breast cancer (BrCa) development. Studies have consistently noted an increase in miR155 levels in serum and/or tissues in patients with BrCa. However, what is less clear is whether this increase in miR155 is a reflection of oncogenic or tumor suppressive properties. To study the effects of miR155 in a transgenic model of BrCA, we developed an MMTV-PyMT mouse deficient in miR155 (miR155-/- PyMT). miR155-/- mice (n = 11) exhibited reduced tumor number and volume palpations at ∼14-18 wk of age compared with miR155 sufficient littermates (n = 12). At 19 wk, mammary glands were excised from tumors for RT-PCR, and tumors were counted, measured, and weighed. miR155-/- PyMT mice exhibited reduced tumor volume, number, and weight, which was confirmed by histopathological analysis. There was an increase in apoptosis with miR155 deficiency and a decrease in proliferation. As expected, miR155 deficiency resulted in upregulated gene expression of suppressor of cytokine signaling 1 (Socs1)-its direct target. There was a reduction in gene expression of macrophage markers (CD68, Adgre1, Itgax, Mrc1) with miR-155-/- and this was confirmed with immunofluorescence staining for F4/80. miR155-/- increased expression of M1 macrophage marker Nos2 and reduced expression of M2 macrophage markers IL-10, IL-4, Arg1, and MMP9. Overall, miR155 deficiency reduced BrCA and improved the tumor microenvironment through the reduction of genes associated with protumorigenic processes. However, given the inconsistencies in the literature, additional studies are needed before any attempts are made to harness miR155 as a potential oncogenic or tumor suppressive miRNA.NEW & NOTEWORTHY To examine the effects of miR155 in a transgenic model of breast cancer, we developed an MMTV-PyMT mouse-deficient in miR155. We demonstrate that global loss of miR155 resulted in blunted tumor growth through modulating the tumor microenvironment. Specifically, miR155-deficient mice had smaller and less invasive tumors, an increase in apoptosis and a decrease in proliferation, a reduction in tumor-associated macrophages, and the expression of genes associated with protumoral processes.

Ojeok-san ameliorates visceral and somatic nociception in a mouse model of colitis induced colorectal cancer

Cancer patients can develop visceral, somatic, and neuropathic pain, largely due to the malignancy itself and its treatments. Often cancer patients and survivors turn to the use of complementary and alternative medicine (CAM) to alleviate pain and fatigue. Thus, it is necessary to investigate how CAM therapies work as novel analgesics to treat cancer pain. Ojeok-san (OJS) is an herbal formula consisting of seventeen herbs. This herbal formula has been shown to possess anti-inflammatory, immunoregulatory, and analgesic properties. In this study, we examined the potential beneficial effects and mechanism of action of OJS in a preclinical model of colitis-associated colorectal cancer. Male and female C57BL/6J mice were exposed to the carcinogen, azoxymethane (AOM, 10 mg/kg) and a chemical inflammatory driver, dextran sulfate sodium (DSS1-2%), to promote tumorigenesis in the colorectum. OJS was given orally (500, 1000, and 2000 mg/kg) to determine its influence on disease activity, tumor burden, nociception, sedation, Erk signaling, and behavioral and metabolic outcomes. In addition, in vitro studies were performed to assess CT-26 cell viability, dorsal root ganglia (DRG) activation, and bone-marrow-derived macrophage (BMDM) inflammatory response to lipopolysaccharide stimulation after OJS treatment. We found that administration of 2000 mg/kg of OJS was able to mitigate mechanical somatic and visceral nociception via Erk signaling without affecting symptom score and polyp number. Moreover, we discovered that OJS has sedative properties and elicits prolonged total sleeping time in AOM/DSS mice. Our in vitro experiments showed that OJS has the capacity to reduce TNFα gene expression in LPS-stimulated BMDM, but no changes were observed in DRG spike number and CT-26 cell proliferation. Taken together, these data suggest that OJS ameliorates nociception in mice and warrants further examination as a potential CAM therapy to promote analgesia.

From inflammatory bowel disease to colorectal cancer: what's the role of miRNAs?

Inflammatory Bowel Disease (IBD) is a chronic inflammatory disease with relapse and remission periods. Ulcerative colitis and Crohn's disease are two major forms of the disease. IBD imposes a lot of sufferings on the patient and has many consequences; however, the most important is the increased risk of colorectal cancer, especially in patients with Ulcerative colitis. This risk is increased with increasing the duration of disease, thus preventing the progression of IBD to cancer is very important. Therefore, it is necessary to know the details of events contributed to the progression of IBD to cancer. In recent years, the importance of miRNAs as small molecules with 20-22 nucleotides has been recognized in pathophysiology of many diseases, in which IBD and colorectal cancer have not been excluded. As a result, the effectiveness of these small molecules as therapeutic target is hopefully confirmed. This paper has reviewed the related studies and findings about the role of miRNAs in the course of events that promote the progression of IBD to colorectal carcinoma, as well as a review about the effectiveness of some of these miRNAs as therapeutic targets.

TLR4 signaling in the development of colitis-associated cancer and its possible interplay with microRNA-155

Ulcerative colitis (UC) has closely been associated with an increased risk of colorectal cancer. However, the exact mechanisms underlying colitis-associated cancer (CAC) development remain unclear. As a classic pattern-recognition receptor, Toll like receptor (TLR)4 is a canonical receptor for lipopolysaccharide of Gram-negative bacteria (including two CAC-associated pathogens Fusobacterium nucleatum and Salmonella), and functions as a key bridge molecule linking oncogenic infection to colonic inflammatory and malignant processes. Accumulating studies verified the overexpression of TLR4 in colitis and CAC, and the over-expressed TLR4 might promote colitis-associated tumorigenesis via facilitating cell proliferation, protecting malignant cells against apoptosis, accelerating invasion and metastasis, as well as contributing to the creation of tumor-favouring cellular microenvironment. In recent years, considerable attention has been focused on the regulation of TLR4 signaling in the context of colitis-associated tumorigenesis. MicroRNA (miR)-155 and TLR4 exhibited a similar dynamic expression change during CAC development and shared similar CAC-promoting properties. The available data demonstrated an interplay between TLR4 and miR-155 in the context of different disorders or cell lines. miR-155 could augment TLR4 signaling through targeting negative regulators SOCS1 and SHIP1; and TLR4 activation would induce miR-155 expression via transcriptional and post-transcriptional mechanisms. This possible TLR4-miR-155 positive feedback loop might result in the synergistic accelerating effect of TLR4 and miR-155 on CAC development.

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.

Identification of a novel immune-related microRNA prognostic model in clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is a type of kidney cancer, and one of the most common malignant tumors. Many studies have shown that certain microRNAs (miRNAs) play an important role in the occurrence and development of ccRCC. Nevertheless, the prognosis of ccRCC patients is very rarely based on these “immuno-miRs”. Our aim was thus to determine the relationship between immune-related miRNA signatures and ccRCC.

Methods

We downloaded the miRNA expression data from 521 KIRC and 71 normal tissues in The Cancer Genome Atlas (TCGA). We used “limma” package and univariate Cox regression analysis to identify differentially expressed miRNAs (DEMs) that related to overall survival (OS). We applied lasso and multivariate Cox regression analyses to construct a prognostic model based on immuno-miRs. We evaluated the performance of model by using the Kaplan-Meier method. Furthermore, Cox regression analysis was used to determine independent prognostic signatures in ccRCC.

Results

A total of 59 significant immuno-miRs were identified. We use univariate Cox regression analysis to acquire 18 immune-related miRNAs which were markedly related to OS of ccRCC patients in the training set. We then constructed the 9-immune-related-miRNA prognostic model (miR-21, miR-342, miR-149, miR-130b, miR-223, miR-365a, miR-9-1, and miR-146b) by using lasso and multivariate Cox regression. Further analysis suggested that the immune-related prognostic model could be an independent prognostic indicator for patients with ccRCC. The prognostic performance of the 9-immune-related-miRNA prognostic model was further validated successfully in the testing set.

Conclusions

We established a novel immune-based prognostic model of ccRCC based on potential prognostic immune-related miRNAs. Our results indicated that the 9-miRNA signature could be a practical and reliable prognostic tool for ccRCC.

Therapeutic Implications of TGFβ in Cancer Treatment: A Systematic Review

Simple Summary

While the importance of transforming growth factor β (TGFβ) in cancer development and progression has long been recognized, a successful therapy targeting this cytokine has not been developed yet. The difficulty in blocking the tumor-promoting activity of this factor while maintaining the tumor suppressor effects can compromise the expected outcomes. This systematic review summarizes and discusses the different strategies being tested to regulate TGFβ expression in cancer treatment, as well as their associated side effects.

Abstract

Transforming growth factor β (TGFβ) is a pleiotropic cytokine that participates in a wide range of biological functions. The alterations in the expression levels of this factor, or the deregulation of its signaling cascade, can lead to different pathologies, including cancer. A great variety of therapeutic strategies targeting TGFβ, or the members included in its signaling pathway, are currently being researched in cancer treatment. However, the dual role of TGFβ, as a tumor suppressor or a tumor-promoter, together with its crosstalk with other signaling pathways, has hampered the development of safe and effective treatments aimed at halting the cancer progression. This systematic literature review aims to provide insight into the different approaches available to regulate TGFβ and/or the molecules involved in its synthesis, activation, or signaling, as a cancer treatment. The therapeutic strategies most commonly investigated include antisense oligonucleotides, which prevent TGFβ synthesis, to molecules that block the interaction between TGFβ and its signaling receptors, together with inhibitors of the TGFβ signaling cascade-effectors. The effectiveness and possible complications of the different potential therapies available are also discussed.

Impact of 5 fluorouracil chemotherapy on gut inflammation, functional parameters, and gut microbiota

Emerging evidence suggests that gut microbiota may influence the response to chemotherapy. We sought to characterize the effects of 5 fluorouracil (5FU) chemotherapy on colon inflammation and functional measures in colorectal cancer (CRC) and to further determine whether gut microbiota can influence this response. 50 C57BL/6 were randomized into four groups; Control + Vehicle (n = 10), Control + 5FU (n = 10), AOM/DSS + Vehicle (n = 15), and AOM/DSS + 5FU (n = 15). CRC was induced chemically by a single 10 mg/kg injection of azoxymethane (AOM) followed by two cycles (2% and 1%) of dextran sodium sulfate (DSS). Mice were then treated with 3 cycles of vehicle or 5FU (cycle 1: 40 mg/kg, cycle 2 + 3: 20 mg/kg). Functional tests (grip strength and run-to-fatigue) were performed prior to 5FU treatment (baseline) and at the completion of the second cycle of 5FU. Following the third 5FU cycle, mice were euthanized and the colon was evaluated for expression of inflammatory genes using RT-qPCR and stool samples were profiled using 16S rRNA sequencing. A second experiment used fecal microbiota transplantation from 5FU treated mice to control mice (n = 10-15/group) to determine whether 5FU associated changes in the microbiota could influence functional measures and colon inflammation. 5FU reduced grip strength (p < 0.05) and caused a trending decrease in run-to-fatigue performance in cancer mice (p = 0.06). Select intestinal inflammatory genes were significantly elevated with 5FU treatment and this was further exacerbated with cancer (p < 0.05). Microbiota analysis revealed increased dissimilarity and alterations in bacterial taxonomy in 5FU and AOM/DSS-treated mice (p < 0.05). Fecal transplant from 5FU treated mice reduced functional performance (p < 0.05) and altered select colon inflammatory markers (p < 0.05). This study provides evidence of an effect of 5FU on inflammatory responses and functional measures in a mouse model of CRC and suggests that gut microbes may play a role in some, but not all, 5FU related perturbations.

The intricate role of miR-155 in carcinogenesis: potential implications for esophageal cancer research

MiRNAs have immerged as essential modulators of key cellular procuresses involved in post-transcriptional regulation of the human transcriptome. They are essential components of complex regulatory networks that modulate most important physiological functions of cells. MicroRNA-155 (miR-155) is a multifaceted regulator of cell proliferation, cell cycle, development, immunity and inflammation that plays pivotal, and sometimes contradictory, roles in numerous cancers including esophageal cancer. Here, we review the intricate role of miR-155 in cancer by exemplifying carcinogenesis of various tumors, focusing on recent findings that may provide a link between miR-155 and esophageal cancer-related pathways.

Non-coding RNAs, the Trojan horse in two-way communication between tumor and stroma in colorectal and hepatocellular carcinoma

In a continuous and mutual exchange of information, cancer cells are invariably exposed to microenvironment transformation. This continuous alteration of the genetic, molecular and cellular peritumoral stroma background has become as critical as the management of primary tumor progression events in cancer cells. The communication between stroma and tumor cells within the extracellular matrix is one of the triggers in colon and liver carcinogenesis. All non- codingRNAs including long non-coding RNAs, microRNAs and ultraconserved genes play a critical role in almost all cancers and are responsible for the modulation of the tumor microenvironment in several malignant processes such as initiation, progression and dissemination. This review details the involvement of non codingRNAs in the evolution of human colorectal carcinoma and hepatocellular carcinoma in relationship with the microenvironment. Recent research has shown that a considerable number of dysregulated non- codingRNAs could be valuable diagnostic and prognostic biomarkers in cancer. Therefore, more in-depth knowledge of the role non- codingRNAs play in stroma-tumor communication and of the complex regulatory mechanisms between ultraconserved genes and microRNAs supports the validation of future effective therapeutic targets in patients suffering from hepatocellular and colorectal carcinoma, two distinctive entities which share quite a lot common non-coding RNAs.

MicroRNA-155 regulates the proliferation, cell cycle, apoptosis and migration of colon cancer cells and targets CBL

MicroRNA-155 (miR-155) is a well-studied miR and acts as an oncomiR in numerous cancer types. However, the biological functions of miR-155 in colon cancer as well as its target genes have remained to be fully elucidated. In order to investigate the biological functions of miR-155, MTT, colony formation and wound healing assays, cell cycle analysis and detection of apoptosis were performed. The results demonstrated that miR-155 promoted the proliferation of colon cancer cells and enhanced their colony formation capacity, promoted their cell cycle progression and inhibited apoptosis. miR-155 also promoted the migration of colon cancer cells. In the present study, casitas B-lineage lymphoma was identified as a novel target of miR-155. The present study suggested that miR-155 functions as an oncomiR in colon cancer cells and may become a promising therapeutic target for colon cancer therapy.

A three-microRNA signature as a diagnostic and prognostic marker in clear cell renal cancer: An In Silico analysis

Accumulating evidence has demonstrated that some specific miRNAs were aberrantly expressed in renal clear cell carcinoma and participated in many biological processes. The aim of this study was to investigate a panel of miRNA signature for diagnosis and prognosis of renal clear cell carcinoma (KIRC). Here, we performed a comprehensive analysis for miRNA expression profiles and corresponding clinical information of 516 KIRC patients from The Cancer Genome Atlas (TCGA). In the study, a total of 63 differentially expressed miRNAs were identified, of which 34 were up-regulated and 29 were down-regulated. We constructed a panel of three-miRNA that were significantly associated with KIRC diagnosis and KIRC patients' prognosis. The three-miRNA signature reached a sensitivity of 98.3% and a specificity of 97.2% in the diagnosis of KIRC. Using the three-miRNA signature, we classified the KIRC patients into high-risk group and low-risk group. The Kaplan- Meier curves showed that KIRC patients with high risk scores had significantly worsen overall survival (OS) and disease free survival (DFS) than KIRC patients with low risk scores. In the univariate and multivariate Cox regression analysis, three-miRNA signature was an independent prognostic factor in OS. In conclusion, the three-miRNA signature could be used as a diagnostic and prognostic biomarker in KIRC, and therefore, may help to provide significant clinical implication for the treatment of KIRC.

Loss of monocyte chemoattractant protein-1 expression delays mammary tumorigenesis and reduces localized inflammation in the C3(1)/SV40Tag triple negative breast cancer model

Monocyte chemoattractant protein 1 (MCP-1) has been implicated as a major modulator in the progression of mammary tumorigenesis, largely due to its ability to recruit macrophages to the tumor microenvironment. Macrophages are key mediators in the connection between inflammation and cancer progression and have been shown to play an important role in tumorigenesis. Thus, MCP-1 may be a potential therapeutic target in inflammatory and difficult-to-treat cancers such as triple negative breast cancer (TNBC). We examined the effect of MCP-1 depletion on mammary tumorigenesis in a model of TNBC. Tumor measurements were conducted weekly (until 22 weeks of age) and at sacrifice (23 weeks of age) in female C3(1)/SV40Tag and C3(1)/SV40Tag MCP-1 deficient mice to determine tumor numbers and tumorvolumes. Histopathological scoring was performed at 12 weeks of age and 23 weeks of age. Gene expression of macrophage markers and inflammatory mediators were measured in the mammary gland and tumor microenvironment at sacrifice. As expected, MCP-1 depletion resulted in decreased tumorigenesis, indicated by reduced primary tumor volume and multiplicity, and a delay in tumor progression represented by histopathological scoring (12 weeks of age). Deficiency in MCP-1 significantly downregulated expression of macrophage markers in the mammary gland (Mertk and CD64) and the tumor microenvironment (CD64), and also reduced expression of inflammatory cytokines in the mammary gland (TNFα and IL-1β) and the tumor microenvironment (IL-6). These data support the hypothesis that MCP-1 expression contributes to increased tumorigenesis in a model of TNBC via recruitment of macrophages and subsequent increase in inflammatory mediators.

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.

Matrix Gla protein repression by miR-155 promotes oncogenic signals in breast cancer MCF-7 cells

MGP is a protein that was initially associated with the inhibition of calcification in skeleton, soft tissues, and arteries, but more recently also implicated in cancer. In breast cancer, higher levels of MGP mRNA were associated with poor prognosis, but since this deregulation was never demonstrated at the protein level, we postulated the involvement of a post-transcriptional regulatory mechanism. In this work we show that MGP is significantly repressed by miR-155 in breast cancer MCF-7 cells, and concomitantly there is a stimulation of cell proliferation and cell invasiveness. This study brings new insights into the putative involvement of MGP and oncomiR-155 in breast cancer, and may contribute to develop new therapeutic strategies.