Serological under expression of microRNA-21, microRNA-34a and microRNA-126 in colorectal cancer

Expression of specific microRNAs in tissue and plasma in colorectal cancer

BACKGROUND

MicroRNAs (miRNA/miR) play significant roles in the regulation of cell differentiation, cell cycle progression, and apoptosis. They become dysregulated during carcinogenesis and are eventually released into the circulation, enabling their detection in body fluids. Thus, this study compared the miRNA expression in tissue and plasma samples of colorectal cancer (CRC) patients and clinically healthy controls and determined miRNA expression as a potential CRC biomarker.

METHODS

Using quantitative reverse transcription polymerase chain reaction (RT-qPCR), miR-21-5p, miR-29a-3p, miR-92a-3p, miR-135b-5p, miR-196b-5p, and miR-197-3p, expression was analyzed and compared between the malignant (n = 41) and the adjacent neoplasm free mucosal tissues (n = 41) of CRC patients. The findings were validated in plasma samples (n = 36) collected from the same CRC patients prior to surgery or any form of treatment and compared to plasma from their age and sex-matched controls (n = 36).

RESULTS

MiR-21-5p, miR-29a-3p, miR-92a-3p, and miR- 196b-5p were upregulated and miR-135b-5p was downregulated in CRC malignant tissues compared to their expression in adjacent neoplasm-free tissue. This was further observed in the plasma of the same CRC cases compared to controls. MiR-92a-3p showed itself the most sensitive (0.93; p < .001) and most specific (0.95; p < .001) in detecting CRC in tissue. In plasma, miR-196b-5p was the most sensitive (0.97; p < .001) and specific (0.94; p < .001) in detecting CRC. Plasma miR-92a-3p and miR-196b-5p were the most sensitive (0.95; p < .001) and specific (0.94; p < .001) in the early detection of CRC.

CONCLUSIONS

Results show that specific miRNAs dysregulated in malignant tissues are released and can be detected in the circulation, supporting their potential as non-invasive biomarkers of CRC.

Liquid Biopsy as a Source of Nucleic Acid Biomarkers in the Diagnosis and Management of Lynch Syndrome

Lynch syndrome (LS) is an autosomal dominant inherited cancer predisposition disorder, which may manifest as colorectal cancer (CRC), endometrial cancer (EC) or other malignancies of the gastrointestinal and genitourinary tract as well as the skin and brain. Its genetic cause is a defect in one of the four key DNA mismatch repair (MMR) loci. Testing of patients at risk is currently based on the absence of MMR protein staining and detection of mutations in cancer tissue and the germline, microsatellite instability (MSI) and the hypermethylated state of the MLH1 promoter. If LS is shown to have caused CRC, lifetime follow-up with regular screening (most importantly, colonoscopy) is required. In recent years, DNA and RNA markers extracted from liquid biopsies have found some use in the clinical diagnosis of LS. They have the potential to greatly enhance the efficiency of the follow-up process by making it minimally invasive, reproducible, and time effective. Here, we review markers reported in the literature and their current clinical applications, and we comment on possible future directions.

microRNAs: Small molecules with a large impact on colorectal cancer

Colorectal cancer (CRC) accounts for one of the main cancer-related mortality and morbidity worldwide. The molecular mechanisms of CRC development have been broadly investigated and, over the last decade, it has become evident that aberrant transcription of microRNAs (miRNAs), a class of small, noncoding RNA molecules, has a significant role in the inception and promotion of CRC. In the involved tissues of CRC, the transcription profile of miRNAs is modulated, and their expression templates are related with prognosis, diagnosis, and treatment outcomes. Here, in the current review, we attempted to discuss the latest information regarding the aberrantly expressed miRNAs in CRC and the advantages of utilizing miRNAs as biomarkers for early diagnosis and prognosis of CRC as well as potential therapeutic application. The effect of miRNAs involved in various signaling pathways, primarily p53, EGFR, Wnt, and TGF-β pathways, was clarified.

Assessment of Serum MicroRNA-21 Gene Expression for Diagnosis and Prognosis of Colorectal Cancer

BACKGROUND

MicroRNAs (miRNAs) are small, non-coding RNAs that are involved in carcinogenesis through posttranscriptional gene regulatory activity. The current study aimed to evaluate serum miR-21 expression levels as potential biomarkers for diagnosis and prognosis of colorectal cancer (CRC) patients.

METHODS

Quantitative real-time RT-PCR was applied to determine the relative expression level of miR-21 in serum. At the same time, the sensitivity and specificity of this marker were evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

miR-21 expression levels of serum were 3.4 and 1.25 in patient and control, respectively (p < 0.05). The sensitivity and specificity of miR-21 were found to be 95.8% and 91.7%, respectively. The high expression level of serum miR-21 were associated with higher local recurrence, TNM staging, PT staging, venous invasion, liver metastasis, and recurrence (p < 0.05).

CONCLUSION

The results of this study indicated that miR-21 expression levels in serum can be considered as a novel non-invasive biomarker for early detection and prognosis of CRC patients.

A Review on the Role of Nanosensors in Detecting Cellular miRNA Expression in Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) is one of the leading causes of death across the globe. Early diagnosis with high sensitivity can prevent CRC progression, thereby reducing the condition of metastasis.

OBJECTIVE

The purpose of this review is (i) to discuss miRNA based biomarkers responsible for CRC, (ii) to brief on the different methods used for the detection of miRNA in CRC, (iii) to discuss different nanobiosensors so far found for the accurate detection of miRNAs in CRC using spectrophotometric detection, piezoelectric detection.

METHODS

The keywords for the review like micro RNA detection in inflammation, colorectal cancer, nanotechnology, were searched in PubMed and the relevant papers on the topics of miRNA related to CRC, nanotechnology-based biosensors for miRNA detection were then sorted and used appropriately for writing the review.

RESULTS

The review comprises a general introduction explaining the current scenario of CRC, the biomarkers used for the detection of different cancers, especially CRC and the importance of nanotechnology and a general scheme of a biosensor. The further subsections discuss the mechanism of CRC progression, the role of miRNA in CRC progression and different nanotechnology-based biosensors so far investigated for miRNA detection in other diseases, cancer and CRC. A scheme depicting miRNA detection using gold nanoparticles (AuNPs) is also illustrated.

CONCLUSION

This review may give insight into the different nanostructures, like AuNPs, quantum dots, silver nanoparticles, MoS2derived nanoparticles, etc., based approaches for miRNA detection using biosensors.

Circular RNA 0060745, a Novel circRNA, Promotes Colorectal Cancer Cell Proliferation and Metastasis Through miR-4736 Sponging

Purpose

Recent studies have shown that noncoding RNAs (ncRNAs) play essential roles in the development of a number of cancers. Circular RNAs (circRNAs) have been shown to contribute to the progression of colorectal cancer (CRC).

Methods

In this study, the expression levels of circular RNA 0060745 (circ_0060745), and microRNA 4736 (miR-4736) were measured using qRT-PCR. Kaplan–Meier survival analysis and receiver operating characteristic (ROC) analysis were used to evaluate the diagnostic value of circ_0060745. Transwell assay and cell counting kit-8 (CCK8) assay were used to determine the metastatic and proliferative capacity of CRC cells. The expression of chromosome segregation one like (CSE1L) was measured using Western blotting and immunohistochemistry (IHC). In addition, RNA pull-down assay and luciferase assay were performed to verify the targeted binding between miR-473,6 and circ_0060745, and between as miR-4736 and CSE1L.

Results

We showed that circ_0060745 was upregulated in CRC, and was associated with unfavorable clinicopathological characteristics. We also showed that circ_0060745 acted as an oncogene and promoted CRC cell proliferation and metastasis. Circ_0060745 was primarily located in the cytoplasm. Furthermore, miR-4736 was downregulated in CRC, was a downstream target of circ_0060745, and mediated proliferation and metastasis. We showed that circ_0060745 sequestered miR-4736, which resulted in CRC cell proliferation and metastasis. Finally, we showed that CSE1L, a downstream target of miR-4736, was upregulated in CRC and mediated suppression of proliferation and metastasis in CRC.

Conclusion

The results of this study showed that circ_0060745 promoted CRC cell proliferation and metastasis via modulation of miR-4736/CSE1L signaling. The Circ_0060745/miR-4736/CSE1L axis might be a novel target for the treatment of CRC.

A meta-analysis on the prognosis of exosomal miRNAs in all solid tumor patients

BACKGROUND

It has been reported that the encapsulated miRNAs from exosomes are potential biomarkers of tumors prognosis. Yet, the results are controversial, so it is obliged to do a meta-analysis to reach a definite conclusion.

MATERIALS AND METHODS

Studies were searched for published in PubMed, Embase, and Web of Science databases until April 20, 2018. A meta-analysis was conducted to appraise the role of exosomal miRNAs in prognosis of cancer patients.

RESULTS

The different exosomal miRNAs expression was remarkably related to overall survival (OS) (hazard ratio [HR] = 2.02, 95% confidence interval [CI]: 1.84-2.21) and disease-free survival (DFS) (HR = 2.43, 95% CI: 1.86-3.17) of cancer patients. High exosomal miR-21 expression was associated with poor OS (HR = 2.59; 95% CI: 1.71-3.90) and DFS (HR = 1.84; 95% CI: 1.37-2.47). High exosomal miR-451a expression was associated with poor OS (HR = 4.81; 95% CI: 2.33-9.93) and DFS (HR = 2.64; 95% CI: 1.62-4.31). High exosomal miR-1290 expression was associated with poor OS (HR = 1.73; 95% CI: 1.29-2.33). Low exosomal miR-638 expression was associated with poor OS (HR = 2.25; 95% CI: 1.46-3.46).

CONCLUSION

The expression levels of exosomal miRNAs, particularly miR-21, miR-451a, miR-1290, and miR-638 could strongly predict prognosis of solid tumor patients and might be a potential target for tumor treatment.

YAP1-induced MALAT1 promotes epithelial-mesenchymal transition and angiogenesis by sponging miR-126-5p in colorectal cancer

Yes-associated protein 1 (YAP1) exerts significant effects in various malignancies. However, the oncogenic role of YAP1 remains controversial, and the mechanism by which YAP1 regulates non-coding RNAs is still largely unknown. The present study aimed to assess the effect of YAP1 on the malignant behaviors of colorectal carcinoma (CRC) and explore the underlying regulatory mechanism of the YAP1-MALAT1-miR-126-5p axis. YAP1 was highly expressed in CRC tissues as assessed by GSE20916 and its expression was negatively correlated with overall survival in 83 CRC cases. Meanwhile, YAP1 promoted proliferation, invasion, and migration in colon cancer cells, in vitro and in vivo. MALAT1 was obviously expressed, with differential expression of 11 lncRNAs in HCT116 cells after transfection with siYAP1 or si-Ctl. Based on bioinformatics prediction, immunoprecipitation (IP), and chromatin immunoprecipitation (ChIP), the interaction of YAP1 with TCF4/β-catenin was regulated by MALAT1. Bioinformatics prediction, dual luciferase assay, RNA-IP, and RNA pull-down assay demonstrated that YAP1-induced MALAT1 promoted the expression of metastasis-associated molecules such as VEGFA, SLUG, and TWIST, by sponging miR-126-5p in CRC. These findings indicated that the YAP1-MALAT1-miR-126-5p axis could control angiogenesis and epithelial-mesenchymal transition in CRC, providing potential biomarkers and therapeutic targets for CRC.

Relationship between Fusobacterium nucleatum, inflammatory mediators and microRNAs in colorectal carcinogenesis

AIM

To examine the effect of Fusobacterium nucleatum (F. nucleatum) on the microenvironment of colonic neoplasms and the expression of inflammatory mediators and microRNAs (miRNAs).

METHODS

Levels of F. nucleatum DNA, cytokine gene mRNA (TLR2, TLR4, NFKB1, TNF, IL1B, IL6 and IL8), and potentially interacting miRNAs (miR-21-3p, miR-22-3p, miR-28-5p, miR-34a-5p, miR-135b-5p) were measured by quantitative polymerase chain reaction (qPCR) TaqMan^® assays in DNA and/or RNA extracted from the disease and adjacent normal fresh tissues of 27 colorectal adenoma (CRA) and 43 colorectal cancer (CRC) patients. KRAS mutations were detected by direct sequencing and microsatellite instability (MSI) status by multiplex PCR. Cytoscape v3.1.1 was used to construct the postulated miRNA:mRNA interaction network.

RESULTS

Overabundance of F. nucleatum in neoplastic tissue compared to matched normal tissue was detected in CRA (51.8%) and more markedly in CRC (72.1%). We observed significantly greater expression of TLR4, IL1B, IL8, and miR-135b in CRA lesions and TLR2, IL1B, IL6, IL8, miR-34a and miR-135b in CRC tumours compared to their respective normal tissues. Only two transcripts for miR-22 and miR-28 were exclusively downregulated in CRC tumour samples. The mRNA expression of IL1B, IL6, IL8 and miR-22 was positively correlated with F. nucleatum quantification in CRC tumours. The mRNA expression of miR-135b and TNF was inversely correlated. The miRNA:mRNA interaction network suggested that the upregulation of miR-34a in CRC proceeds via a TLR2/TLR4-dependent response to F. nucleatum. Finally, KRAS mutations were more frequently observed in CRC samples infected with F. nucleatum and were associated with greater expression of miR-21 in CRA, while IL8 was upregulated in MSI-high CRC.

CONCLUSION

Our findings indicate that F. nucleatum is a risk factor for CRC by increasing the expression of inflammatory mediators through a possible miRNA-mediated activation of TLR2/TLR4.

Role of miRNA-210, miRNA-21 and miRNA-126 as diagnostic biomarkers in colorectal carcinoma: impact of HIF-1α-VEGF signaling pathway

Colorectal cancer (CRC) is a major cause of death worldwide. Novel non-invasive, high diagnostic value screening test is urgently needed to improve survival rate, treatment and prognosis. Stable, small, circulating microRNA (miRNA) offers unique opportunities for the early diagnosis of several diseases. It acts as tumor oncogenes or suppressors and involve in cell death, survival, and metastasis. Communication between miRNA and carcinogenesis is critical but it still not clear and needs further investigation. The aim of our study is to evaluate the role of miR-210, miR-21, miR-126, as non-invasive diagnostic biomarkers for screening, early detection of CRC, studying their correlation with prognostic variables, and clarifying the roles of miRNAs on HIF-1α-VEGF signaling pathway. The expression of miR-210, miR-21 and miR-126 was performed using qRT-PCR in adenocarcinoma (no = 35), adenomas (no = 51), and neoplasm free controls (no = 101). Serum levels of VEGF and HIF-1α was determined by ELISA Kit. The results show that the expression of miR-210, miR-21, VEGF, HIF-1α was significantly up-regulated while that miRNA-126 was down-regulated in both adenocarcinoma and adenomas compared with controls (p < 0.001 for each). No significant difference was noted comparing patients with adenocarcinoma and adenomas. The three miRNAs correlated with VEGF, HIF-α. The miR-210 and miR-21 associated with TNM classification and clinical staging of adenocarcinoma (p < 0.001) and they show high diagnostic value with sensitivity and specificity 88.6%, 90.1% and 91.4%, 95.0% respectively. Our study revealed that circulating miR-210, miR-21 were up-regulated while miR-126 was down-regulated in CRC and adenomas patients, they all correlated with TNM staging and they had high diagnostic value. HIF-1α VEGF signaling pathways regulated by miRNAs played a role in colon cancer initiation. To the best of our knowledge, this is the first study of this miRNAs panel in CRC in our community. These data suggested that these biomarkers could be a potential novel, non-invasive marker for early diagnosis, screening and predicting prognosis of CRC. Understanding the molecular functions by which miRNAs affect cancer and understanding its roles in modulating the signaling output of VEGF might be fruitful in reducing the incidence and slowing the progression of this dark malignancy.

Relevance of MicroRNAs as Potential Diagnostic and Prognostic Markers in Colorectal Cancer

Colorectal cancer (CRC) is currently the third and the second most common cancer in men and in women, respectively. Every year, more than one million new CRC cases and more than half a million deaths are reported worldwide. The majority of new cases occur in developed countries. Current screening methods have significant limitations. Therefore, a lot of scientific effort is put into the development of new diagnostic biomarkers of CRC. Currently used prognostic markers are also limited in assessing the effectiveness of CRC therapy. MicroRNAs (miRNAs) are a promising subject of research especially since single miRNA can recognize a variety of different mRNA transcripts. MiRNAs have important roles in epigenetic regulation of basic cellular processes, such as proliferation, apoptosis, differentiation, and migration, and may serve as potential oncogenes or tumor suppressors during cancer development. Indeed, in a large variety of human tumors, including CRC, significant distortions in miRNA expression profiles have been observed. Thus, the use of miRNAs as diagnostic and prognostic biomarkers in cancer, particularly in CRC, appears to be an inevitable consequence of the advancement in oncology and gastroenterology. Here, we review the literature to discuss the potential usefulness of selected miRNAs as diagnostic and prognostic biomarkers in CRC.

A multi-omic atlas of the human frontal cortex for aging and Alzheimer's disease research

We initiated the systematic profiling of the dorsolateral prefrontal cortex obtained from a subset of autopsied individuals enrolled in the Religious Orders Study (ROS) or the Rush Memory and Aging Project (MAP), which are jointly designed prospective studies of aging and dementia with detailed, longitudinal cognitive phenotyping during life and a quantitative, structured neuropathologic examination after death. They include over 3,322 subjects. Here, we outline the first generation of data including genome-wide genotypes (n=2,090), whole genome sequencing (n=1,179), DNA methylation (n=740), chromatin immunoprecipitation with sequencing using an anti-Histone 3 Lysine 9 acetylation (H3K9Ac) antibody (n=712), RNA sequencing (n=638), and miRNA profile (n=702). Generation of other omic data including ATACseq, proteomic and metabolomics profiles is ongoing. Thanks to its prospective design and recruitment of older, non-demented individuals, these data can be repurposed to investigate a large number of syndromic and quantitative neuroscience phenotypes. The many subjects that are cognitively non-impaired at death also offer insights into the biology of the human brain in older non-impaired individuals.

Levels of MicroRNA Heterogeneity in Cancer Biology

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression, involved in the silencing of messenger RNA (mRNA) translation. The importance of miRNA signatures in disease screening, prognosis, and progression of different tumor types and subtypes is increasing. miRNA expression levels change depending on numerous factors. In this review, we are describing the circumstances under which miRNA levels can change, these are named 'levels' of heterogeneity of miRNAs. miRNAs can have oncogenic, tumor suppressive, or both roles depending on tumor type and target mRNA whose translation they silence. The expression levels of a single miRNA may vary across different cancer types and subtypes, indicating that a miRNA signature may be tissue specific. miRNA levels of expression also vary during disease formation and propagation, indicating the presence of a time profile for their expression. The complexity of the miRNA-mRNA interference network mirrors different genetic and epigenetic changes that influence miRNA and mRNA availability to each other, and hence, their binding ability. The potential role of miRNAs as biomarkers is two-fold; first, for monitoring of the phases of cancer pathogenesis, and second, to characterize the particular type/subtype of cancer. It is important that a particular miRNA should be characterized by examining as many types and subtypes of cancers as are available, as well as being extracted from different types of samples, in order to obtain a complete picture of its behavior and importance in the disease pathology.

Epigenetic Dysregulation of the Dynamin-Related Protein 1 Binding Partners MiD49 and MiD51 Increases Mitotic Mitochondrial Fission and Promotes Pulmonary Arterial Hypertension: Mechanistic and Therapeutic Implications

BACKGROUND

Mitotic fission is increased in pulmonary arterial hypertension (PAH), a hyperproliferative, apoptosis-resistant disease. The fission mediator dynamin-related protein 1 (Drp1) must complex with adaptor proteins to cause fission. Drp1-induced fission has been therapeutically targeted in experimental PAH. Here, we examine the role of 2 recently discovered, poorly understood Drp1 adapter proteins, mitochondrial dynamics protein of 49 and 51 kDa (MiD49 and MiD51), in normal vascular cells and explore their dysregulation in PAH.

METHODS

Immunoblots of pulmonary artery smooth muscle cells (control, n=6; PAH, n=8) and immunohistochemistry of lung sections (control, n=6; PAH, n=6) were used to assess the expression of MiD49 and MiD51. The effects of manipulating MiDs on cell proliferation, cell cycle, and apoptosis were assessed in human and rodent PAH pulmonary artery smooth muscle cells with flow cytometry. Mitochondrial fission was studied by confocal imaging. A microRNA (miR) involved in the regulation of MiD expression was identified using microarray techniques and in silico analyses. The expression of circulatory miR was assessed with quantitative reverse transcription-polymerase chain reaction in healthy volunteers (HVs) versus patients with PAH from Sheffield, UK (plasma: HV, n=29, PAH, n=27; whole blood: HV, n=11, PAH, n=14) and then confirmed in a cohort from Beijing, China (plasma: HV, n=19, PAH, n=36; whole blood: HV, n=20, PAH, n=39). This work was replicated in monocrotaline and Sugen 5416-hypoxia, preclinical PAH models. Small interfering RNAs targeting MiDs or an miR mimic were nebulized to rats with monocrotaline-induced PAH (n=4-10).

RESULTS

MiD expression is increased in PAH pulmonary artery smooth muscle cells, which accelerates Drp1-mediated mitotic fission, increases cell proliferation, and decreases apoptosis. Silencing MiDs (but not other Drp1 binding partners, fission 1 or mitochondrial fission factor) promotes mitochondrial fusion and causes G1-phase cell cycle arrest through extracellular signal-regulated kinases 1/2- and cyclin-dependent kinase 4-dependent mechanisms. Augmenting MiDs in normal cells causes fission and recapitulates the PAH phenotype. MiD upregulation results from decreased miR-34a-3p expression. Circulatory miR-34a-3p expression is decreased in both patients with PAH and preclinical models of PAH. Silencing MiDs or augmenting miR-34a-3p regresses experimental PAH.

CONCLUSIONS

In health, MiDs regulate Drp1-mediated fission, whereas in disease, epigenetic upregulation of MiDs increases mitotic fission, which drives pathological proliferation and apoptosis resistance. The miR-34a-3p-MiD pathway offers new therapeutic targets for PAH.

Colorectal Cancer and Alcohol Consumption-Populations to Molecules

Colorectal cancer (CRC) is a major cause of morbidity and mortality, being the third most common cancer diagnosed in both men and women in the world. Several environmental and habitual factors have been associated with the CRC risk. Alcohol intake, a common and rising habit of modern society, is one of the major risk factors for development of CRC. Here, we will summarize the evidence linking alcohol with colon carcinogenesis and possible underlying mechanisms. Some epidemiologic studies suggest that even moderate drinking increases the CRC risk. Metabolism of alcohol involves ethanol conversion to its metabolites that could exert carcinogenic effects in the colon. Production of ethanol metabolites can be affected by the colon microbiota, another recently recognized mediating factor to colon carcinogenesis. The generation of acetaldehyde and alcohol's other metabolites leads to activation of cancer promoting cascades, such as DNA-adduct formation, oxidative stress and lipid peroxidation, epigenetic alterations, epithelial barrier dysfunction, and immune modulatory effects. Not only does alcohol induce its toxic effect through carcinogenic metabolites, but alcoholics themselves are predisposed to a poor diet, low in folate and fiber, and circadian disruption, which could further augment alcohol-induced colon carcinogenesis.

Circulating Exosomal MicroRNA-21 as a Biomarker in Each Tumor Stage of Colorectal Cancer

OBJECTIVE

We clarified the predictive and prognostic value of circulating plasma exosomal microRNA-21 (miR-21) in each TNM stage of colorectal cancer (CRC) patients.

METHODS

The microRNA (miRNA) profiles of the plasma exosomes, primary tumor tissues, and liver metastasis tissues from the same CRC patients were examined using a microarray. For validation analysis, the plasma exosome samples from 326 CRC patients were measured by TaqMan miRNA assays.

RESULTS

In the miRNA microarray analyses, miR-21 showed the highest upregulation in exosomes, primary tumor tissues, and liver metastasis tissues. Significant correlations were demonstrated between exosomal miR-21 and tissue miR-21 levels. As for the relationship to the pathological condition, exosomal miR-21 showed a significant association with liver metastasis and TNM stage. The overall survival (OS) rates and disease-free survival (DFS) rates in high-exosomal-miR-21 patients were significantly worse than those in low-miR-21 patients. Exosomal miR-21 levels were an independent prognostic factor for OS and DFS in CRC patients with TNM stage II or III, and for OS in patients with TNM stage IV.

CONCLUSION

Plasma exosomal miR-21 levels are a useful biomarker for the prediction of recurrence and poor prognosis in CRC patients with TNM stage II, III, or IV.

Colorectal Carcinoma: A General Overview and Future Perspectives in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death. Most cases of CRC are detected in Western countries, with its incidence increasing year by year. The probability of suffering from colorectal cancer is about 4%–5% and the risk for developing CRC is associated with personal features or habits such as age, chronic disease history and lifestyle. In this context, the gut microbiota has a relevant role, and dysbiosis situations can induce colonic carcinogenesis through a chronic inflammation mechanism. Some of the bacteria responsible for this multiphase process include Fusobacterium spp, Bacteroides fragilis and enteropathogenic Escherichia coli. CRC is caused by mutations that target oncogenes, tumour suppressor genes and genes related to DNA repair mechanisms. Depending on the origin of the mutation, colorectal carcinomas can be classified as sporadic (70%); inherited (5%) and familial (25%). The pathogenic mechanisms leading to this situation can be included in three types, namely chromosomal instability (CIN), microsatellite instability (MSI) and CpG island methylator phenotype (CIMP). Within these types of CRC, common mutations, chromosomal changes and translocations have been reported to affect important pathways (WNT, MAPK/PI3K, TGF-β, TP53), and mutations; in particular, genes such as c-MYC, KRAS, BRAF, PIK3CA, PTEN, SMAD2 and SMAD4 can be used as predictive markers for patient outcome. In addition to gene mutations, alterations in ncRNAs, such as lncRNA or miRNA, can also contribute to different steps of the carcinogenesis process and have a predictive value when used as biomarkers. In consequence, different panels of genes and mRNA are being developed to improve prognosis and treatment selection. The choice of first-line treatment in CRC follows a multimodal approach based on tumour-related characteristics and usually comprises surgical resection followed by chemotherapy combined with monoclonal antibodies or proteins against vascular endothelial growth factor (VEGF) and epidermal growth receptor (EGFR). Besides traditional chemotherapy, alternative therapies (such as agarose tumour macrobeads, anti-inflammatory drugs, probiotics, and gold-based drugs) are currently being studied to increase treatment effectiveness and reduce side effects.

MicroRNAs and long non-coding RNAs in digestive system malignancies

The mammalian transcriptome includes a large number of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Some studies have reported that numerous kinds of miRNAs and lncRNAs have been implicated in playing key regulatory roles in the occurrence and development of digestive system malignances. Therefore, they are closely related to the clinical diagnosis, treatment and prognosis of digestive system malignances. This review focuses on the recent progress in research of miRNAs and lncRNAs in in digestive system malignancies and discusses their epigenetics roles as oncogenes or tumor suppressors. The current and future potential clinical applications of miRNAs and lncRNAs in digestive system malignancies are also discussed, with an aim to provide new ideas and means for the diagnosis, treatment and prognosis of digestive system malignancies.

miR-126 affects the invasion and migration of glioma cells through GATA4

We aimed to explore the relationship between miR-126 and glioma. miR-126 was highly expressed in low-grade clinical glioma tissue samples but lowly expressed in high-grade ones (P < .01). A human endogenous miR-126 expression vector was constructed. The migration capacity of cells transfected with the vector significantly decreased (P < .05). Up-regulation of miR-126 suppressed GATA4 protein expression. After transfection, they slightly contracted and became ovally or spherically shaped. F-actin significantly reduced, and microfilaments shortened or disappeared. The number of membrane-penetrating cells significantly decreased (P < .01). miR-126 inhibits the migration and invasion of glioma cells, which may be linked to GATA4 as a target gene.

Combined expression of miR-34a and Smac mediated by oncolytic vaccinia virus synergistically promote anti-tumor effects in Multiple Myeloma

Despite great progress made in the treatment of multiple myeloma (MM), it is still incurable. Promising phase II clinical results have been reported recently for oncolytic vaccinia virus (OVV) clinic therapeutics. One reason for this has focused on the critical therapeutic importance of the immune response raised by these viruses. However, few studies have performed their applications as an optimal delivery system for therapeutic gene, especially miRNA in MM. In this study, we constructed two novel OVVs (TK deletion) that express anti-tumor genes, miR-34a and Smac, respectively, in MM cell lines and xenograft model. The results demonstrated that the novel OVV can effectively infect MM cell lines, and forcefully enhance the exogenous gene (miR-34a or Smac) expression. Furthermore, utilization of VV-miR-34a combined with VV-Smac synergistically inhibited tumor growth and induced apoptosis in vitro and in vivo. The underlying mechanism is proposed that blocking of Bcl-2 by VV-miR-34a increases the release of cytochrome c from mitochondria and then synergistically amplifies the antitumor effects of Smac-induced cell apoptosis. Our study is the first to utilize OVV as the vector for miR-34a or Smac expression to treat MM, and lays the groundwork for future clinical therapy for MM.